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https://365financialanalyst.com/free-videos/dupont-analysis-a-pyramid-of-ratios/
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# DuPont Analysis – A Pyramid of Ratios
Ratio analysis is a powerful technique widely used by financial analysts across the globe. There is virtually no way to analyze a business without examining a set of ratios from its financial statements. As powerful as it may be, ratio analysis is rarely enough just on its own. A more comprehensive examination requires taking a step further for a more in-depth understanding of a company’s ratios. There is a well-known and widely used approach to such an analysis and it starts with one of the key profitability ratios.
## Return on equity
Return on equity is amongst the most important ratios, especially from an investor’s standpoint, because:
• Unlike most other ratios, it takes numbers from both the income statement and the balance sheet – so it examines both the business’ operational performance and its financial position;
• Unlike most other cross-statement ratios, it takes bottom-line numbers or totals; in other words, it does not focus on some fraction (like DIO on inventory or DPO on payables), but looks at the big picture;
• And last but not least, it goes straight to the point most investors are interested in: what did we make on our investment?
Its importance and comprehensiveness make it the perfect target for a more thorough investigation. Digging a little deeper into ROE’s composition, its drivers and their influence on it, should help us understand the business we are analyzing in a better and more integrated way.
## DuPont Analysis
About a hundred years ago, a man named Frank Donaldson Brown came up with a framework that nicely decomposes a company’s ROE into constituent parts that are informative in and of themselves. As Mr. Brown was the treasurer of DuPont at the time, his framework became known as DuPont Analysis (a.k.a. DuPont’s Model or DuPont’s Pyramid).
The framework is widely used to this day by financial analysts because, by decomposing one of the most important ratios of any business, it provides a clear and comprehensive view into its financials.
How does it work?
## Step 1
Start by decomposing Return on Equity into its key components. This is how it looks mathematically:
ROE = \frac{Net~Income}{Avge~Total~Equity} = \frac{Net~Income * Avge~Total~Assets}{Avge~Total~Equity * Avge~Total~Assets} = \frac{Net~Income}{Avge~Total~Assets} * \frac{Avge~Total~Assets}{Avge~Total~Equity}= ROA * Leverage
So, return on equity depends on what the company returns on all its assets (ROA), and that gets multiplied by the company’s leverage (sometimes called equity multiplier). If the company is highly leveraged, then equity owners would be getting more return on their investment. That is demonstrated in our practical example but – long story short – if a company has no liabilities, equity equals assets, and then ROA is multiplied by 1/1 = 1; if a company has 50% equity and 50% liabilities, ROA is multiplied by 1/0.5 = 2.
## Step 2
Return on Assets is decomposed into its key components so we can better understand wat drives it:
ROA = \frac{Net Income}{Avge~Total~Assets} = \frac{Revenue * Net~Income}{Revenue * Avge~Total~Assets} = \frac{Revenue}{Avge~Total~ Assets} * \frac{Net~Income}{Revenue} = Asset~Turnover * Net~Profit~Margin
So, the return on the company’s assets depends on the amount of revenue it could generate using these assets, and then on the overall profitability of that revenue (once all the costs have been removed).
We can now see that a company’s ROE can be decomposed to its net profit, asset turnover, and leverage. That is what the 3-way DuPont model looks like:
ROE = \frac{Net Profit}{Revenue} * \frac{Revenue}{Avge~Total~Assets} * \frac{Avge~Total~Assets}{Avge~Total~Equity}
So, we have profitability, efficiency, and leverage. All three can greatly influence ROE:
• High profitability is an obvious driver of return on equity – a higher portion of clients’ money go into the firm;
• High efficiency (turnover) can drive ROE up through volume – more money comes in relative to the firm’s size;
• High leverage multiplies the first two – as ROA goes to a smaller portion on the right side of the balance sheet.
## Step 3
Net profit margin can be decomposed further so that we can see the relationship between operating profit, interest burden, and tax burden.
Net~Profit~Margin = \frac{Net~Profit}{Revenue} = \frac{Net Profit}{EBT} * \frac{EBT}{EBIT}* \frac{EBIT}{Revenue}
So, we can see that overall profitability depends on the profitability of the company’s operations but also on what has to go to its creditors and the tax authorities. The first two ratios’ maximum value can be 1. That is the best possible scenario as far as profit is concerned: in that case, Net Profit = EBIT and there is no taxation or interest payments. However, the former would mean there is no profit to speak of (otherwise there’d be taxes); and the latter suggests no long-term debt, which would in turn mean lower leverage, and so ROE would most likely suffer under such an arrangement.
This is the 5-way DuPont analysis, where we have this long chain of ratios:
ROE = \frac{Net~Profit}{EBT} * \frac{EBT}{EBIT} * \frac{EBIT}{Revenue} * \frac{Revenue}{Avge~Total~Assets} * \frac{Avge~Total~Assets}{Avge~Total~Equity}
If we look at them over time and compare them to industry averages, we can identify areas of strengths and weaknesses or emerging trends.
## The Pyramid of Ratios
There is a popular graphical representation of the DuPont framework, known as the pyramid of ratios. While it notes leverage, it is mostly focused on the return-on-assets part (a.k.a. return on capital) and the relationship between profitability and efficiency.
Unfortunately, this is hard to represent over time; yet, it can give a very clear picture of the situation at present and can be an invaluable tool for managers and investors.
## Limitations of DuPont Analysis
Similar to other ratios, DuPont analysis is only as good as the data that go into it. Accounting treatment of certain expenses (e.g. capitalization of interest, different cost flow methods, etc.) can distort the numbers that form the ratios; therefore, analysts should be careful and make the necessary adjustments when comparing two companies. However, this is not unique to DuPont’s only: it can be stated for any other financial analysis method.
It also does not reveal why certain ratios are higher or lower or even if they should be considered high or low per se. Still, looking at the DuPont framework over time and in comparison to industry averages can quickly reveal:
• what drives a company’s ROE,
• what could be the long-term implications of this, and
• should its management focus its efforts on cost control, asset management or the debt burden.
For a fundamental understanding and practical applications of the model, go ahead and read the article “DuPont Analysis: A Practical Example”.
If you want an example of an DuPont Analysis in Excel, take a look at our DuPont Analysis Excel model.
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http://mathoverflow.net/questions/28235/variants-of-gr%c3%b6nwalls-theorem
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# Variants of Grönwall's theorem
Except the original Grönwall's theorem that $$\limsup_{n \to \infty} \frac{\sigma(n)}{n \log \log n} = e^{\gamma},$$ and the two variants $$\limsup_{\begin{smallmatrix} n\to\infty\cr n\ \text{is square free}\end{smallmatrix}} \frac{\sigma(n)}{n \log \log n} = \frac{6e^{\gamma}}{\pi^2}$$ and $$\limsup_{\begin{smallmatrix} n\to\infty\cr n\ \text{is odd}\end{smallmatrix}} \frac{\sigma(n)}{n \log \log n} = \frac{e^{\gamma}}{2}$$ that have been proven here, are there any other similar statements known?
-
Do you mean "similar statements" for the sum of divisors function $\sigma(n)=\sum_{d\mid n}d$? Because there are plenty of other multiplicative function for which similar asymptotics are known. – Wadim Zudilin Jun 15 '10 at 11:29
"that have been proven here," Where? – Andres Caicedo Jun 15 '10 at 13:47
I fixed the typos. Theorem 9 in the cited preprint contains 5 more similar asymptotics. I wonder what is wanted. – Wadim Zudilin Jun 15 '10 at 14:50
Maybe a statement with $\limsup_{\begin{smallmatrix}n\to \infty \cr n\in S\end{smallmatrix}}(\cdots)=d_S e^{\gamma}$. Where $d_S$ is the density of $S$. – Gjergji Zaimi Jun 15 '10 at 15:02
I'm sorry for not being clear enough, it's my first question here, though. I mean similar statments for the $\sigma(n)$ function, not necessarily asymptotics, but anything that involves limit points of the function $\frac{\sigma(n)}{n \log \log n}$. For example, is there an important sequence $a_n$ such that $\frac{\sigma{a_n}}{n \log \log n}$ converges, besides the sequence of primes? A result that establishes the connection between the density and the limit superior? Etc. Nothing particular. – nikmil Jun 15 '10 at 22:53
where the limit of the Choie, Lichiardopol, Moree and Sole's $$f_1(a_n) = \frac{\sigma(a_n)}{a_n \log \log a_n}$$ is the same $$e^\gamma .$$ That is, the limit for these numbers is the lim sup for all numbers.
These are more natural than people realize. There is a simple recipe that takes some $\epsilon > 0$ and gives an explicit factorization for the best value $n_\epsilon;$ see page 7 in the Briggs pdf "Notes on the Riemann hypothesis and abundant numbers" at the bottom of the Wikipedia entry. The exponent of a prime $p$ in the factorization of $n_\epsilon$ is $$\left\lfloor \log_p \left( \frac{p^{1 + \epsilon} - 1}{p^\epsilon -1} \right) \right\rfloor - 1$$
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https://www.gamedev.net/forums/topic/444544-function-pointer-with-unknown-agrs/
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# Function pointer with unknown agrs??
This topic is 4260 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.
## Recommended Posts
I'm trying to create a wrapper class to automate some of the anglescript setup. I would like to be able to wrap this function:
virtual int RegisterGlobalFunction(const char *declaration, const asUPtr &funcPointer, asDWORD callConv) = 0;
To use the RegisterGlobalFunction, you have to wrap the function address in a 'asFunction' macro like:
r = engine->RegisterGlobalFunction("void Print(string &in)", asFUNCTION(PrintString), asCALL_CDECL); assert( r >= 0 );
So I would like to somehow get rid of this, and automatically do this. My first go was this:
void TScript::ExposeFn( const std::string *declaration, const asUPtr &funcPointer )
but then I think I need the macro wrapper again. So I would really like something like:
void TScript::ExposeFn( const std::string *declaration, fnPtr &funcPointer )
where funcPointer could have any type of arguments and the underlying code would wrap the passed function in asFUNCTION and then pass it off to the angelscript function. I'm just not sure a)if this can be done b)how to any pointers would be great! Cheers
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I don't quite follow. Do you want to be able to call any function, given only a pointer to the function (void* or whatever), and a variable argument list (So essentially make the call yourself)? If so, you'll have to do some assembly to push the relevant parameters onto the stack.
One of the Game Programming Gems gooks has a bit about this in it somewhere (I'll look it out tonight if this is what you need)
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Ummm I dont see the problem, cant you just use templates?
template<typename FuncType>void TScript::ExposeFn( const std::string *declaration, FuncType &funcPointer )
If you want more type safety then you can use boost.preprocessor to generate template overloads for each number of arguments garunteing that the passef in item is actually a function
template<typename R>void TScript::ExposeFn( const std::string *declaration, R (&funcPointer)() )template<typename R, typename T0>void TScript::ExposeFn( const std::string *declaration, R (&funcPointer)(T0) )template<typename R, typename T0, typename T1>void TScript::ExposeFn( const std::string *declaration, R (&funcPointer)(T0, T1) )// Or with BOOST_PP#define GEN_OVERLOAD(z, n, data) \ template<typename R BOOST_PP_ENUM_TRAILING_PARAMS(n, typename T)> \ void TScript::ExposeFn( const std::string *declaration, \ R (&funcPointer)(BOOST_PP_ENUM_PARAMS(n, T)) )// generate overloads for 0-9 paramatersBOOST_PP_REPEAT(10, GEN_OVERLOAD, ~)#undef GEN_OVERLOAD
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I implemented Angelscript in my engine last week and did some macros for this.
#define ScriptFunction(returnType, function, usage) scriptEngine->RegisterGlobalFunction(#returnType" "#function#usage, asFUNCTION(function), asCALL_CDECL);
Example of usage:
// Define a functionint add(int x, int y){ return x + y;}int main(){ // Make function available from the script ScriptFunction(int, add, "(int, int)"); return 0;}
I am not sure if it was exactly this way you use it. But you see the idea anyway. I also added support for member functions. You can look at my code here if you want to: http://openfury.svn.sourceforge.net/viewvc/openfury/trunk/include/engine/scriptmacros.h?view=markup
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Oh ok i just read what Klarre wrote, if thats what you want then id utilize the type system.
// traits class to give the name of a type as a stringtemplate<typename T>struct script_func_traits{ static const char* type_name;};template<typename T>const char* script_func_traits<T>::type_name = typeid(T).name();// specialize for built in types and any classes you want to use#define SCRIPT_FUNC_TRAITS_SPECIALIZATION(type) \ template<> \ struct script_func_traits<type> \ { \ static const char* type_name; \ }; \ \ template<> \ const char* script_func_traits<type>::type_name = #typeSCRIPT_FUNC_TRAITS_SPECIALIZATION(int)SCRIPT_FUNC_TRAITS_SPECIALIZATION(unsigned int)SCRIPT_FUNC_TRAITS_SPECIALIZATION(char)SCRIPT_FUNC_TRAITS_SPECIALIZATION(long)// ...#undef SCRIPT_FUNC_TRAITS_SPECIALIZATION// function that takes the function name and function pointer and registers it#define GEN_REGISTER_FUNCTION(z, n, _) \ template<typename R BOOST_PP_ENUM_TRAILING_PARAMS(n, typename T)> \ void register_function(const std::string& name, \ R (&func)(BOOST_PP_ENUM_PARAMS(n, T))) \ { \ /* construct the prototype string "R name(T0, T1, ..., Tn)" */ \ std::string prototype = script_func_traits<R>::type_name + \ (" " + name) + "(" + \ BOOST_PP_ENUM_BINARY_PARAMS \ ( n, \ script_func_traits<T,>::type_name + "," + BOOST_PP_INTERCEPT \ ) \ ")"; \ r = engine->RegisterGlobalFunction(prototype.c_str(), \ asFUNCTION(func), \ asCALL_CDECL); \ assert( r >= 0 ); \ }/* genrate overloads for functions with 0 - 9 paramaters */BOOST_PP_REPEAT(10, GEN_REGISTER_FUNCTION, ~)#undef GEN_REGISTER_FUNCTION/* utility macro */#define REGISTER_SCRIPT_FUNCTION(function) \ register_function(#function, function)
Edit: Fixed the errors Deyja mentioned. You might be able to overcome the differences in type names by editing SCRIPT_FUNC_TRAITS_SPECIALIZATION to take the name of the type in AngelScript but im not sure because ive never used it.
[Edited by - Julian90 on April 20, 2007 6:52:26 AM]
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You should have posted this in the AngelScript forums.
Why, exactly, is invoking asFUNCTION so dreaded? This seems to be a lot of over-engineered fluff to avoid one little macro which you just end up invoking anyway. Julian90's implementation is interesting in that it seems to be building the signature string on the fly. Except that it doesn't put a space between the return type and the function name, and doesn't put any commas in the argument list. Unfortunately, it wouldn't work, because the names of AngelScript types aren't the same as the names in C++.
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Quote:
Do you want to be able to call any function, given only a pointer to the function (void* or whatever), and a variable argument list (So essentially make the call yourself)?
I think that kinda was the plan...somewhat combined with what Klarre is doing, but without macros.
Quote:
You should have posted this in the AngelScript forums.
Sorry, I felt it was more suited to general programming as it is more of a programming question.
Quote:
Why, exactly, is invoking asFUNCTION so dreaded?
I have no idea! Actually I do - it isn't. I just thought it would be something cool to be able to do, but it appears pretty intense with *a lot* of overhead bloat, which I don't really want. I think I might just go with:
void TScript::ExposeFn( const std::string *declaration, const asUPtr &funcPointer )//call itscript->ExposeFn("int print(int, int)",asFUNCTION(myfn));
I would still be very interested in seeing evil steve's method. Is this the way that printf handles the multiple arguments?
PS. I'm sorry for my slight incoherence above. I guess it was just too early in the morning...
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https://www.thetrendymommy.com/esprito-saint/
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# Esprito Saint
t. It can be ashamed? Is. 63:10: ' ' They, however, if had rebelled, and contristaram its Esprito Saint; for what if it became to them in enemy, and he himself fought against eles' '. u. The Beatles is open to suggestions. It can suffer resistance? At.
7:51: ' ' Men of hard cervix, and incircuncisos of heart and ear, you always you resist the Espirito Santo; as they had made it your parents, thus also vs' '. v. It can be attemped? At. 5:9: ' ' Then Peter said to it: Why he is that you combined between you to try the Spirit Mr.? Here it is there to the door the feet of that had buried your husband, and you they will also take ti' '. 3. ITS OPERATIONS. It convinces? Jo. 16:8: ' ' when it to come, will convince the world the sin, justice and juzo' '.
b. It inhabits? Jo. 14:16,17: ' ' I will supplicate the Father, and it he will give another Comforter to you, so that he is with you forever; to know, the Spirit of the truth, which the world cannot receive; because it does not see it knows nor it; but know it, because it inhabits with you, and will be in vs' '. c. It consoles? Jo.14: 16: ' ' I will supplicate the Father, and it he will give another Comforter to you, so that he is with you forever ' '. d. It discloses? Ef. 5:3: ' ' which in other generations was not revealed the children of the men, as one now showed in the Spirit to its apstolos saints and prophet ' '. e. Santifica? I Co. 6:11: ' ' such you were some of you; but you were washed, but you were santificados, but you were justified on behalf of Mr. Jesus Christ and in the Spirit of our Deus' '.
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http://www.ams.org/bookstore?fn=20&arg1=mmonoseries&ikey=MMONO-160
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New Titles | FAQ | Keep Informed | Review Cart | Contact Us Quick Search (Advanced Search ) Browse by Subject General Interest Logic & Foundations Number Theory Algebra & Algebraic Geometry Discrete Math & Combinatorics Analysis Differential Equations Geometry & Topology Probability & Statistics Applications Mathematical Physics Math Education
Linear and Nonlinear Perturbations of the Operator $$\operatorname{div}$$
V. G. Osmolovskiĭ, St. Petersburg State University, Russia
SEARCH THIS BOOK:
Translations of Mathematical Monographs
1997; 104 pp; hardcover
Volume: 160
ISBN-10: 0-8218-0586-X
ISBN-13: 978-0-8218-0586-2
List Price: US$59 Member Price: US$47.20
Order Code: MMONO/160
The perturbation theory for the operator div is of particular interest in the study of boundary-value problems for the general nonlinear equation $$F(\dot y,y,x)=0$$. Taking as linearization the first order operator $$Lu=C_{ij}u_{x_j}^i+C_iu^i$$, one can, under certain conditions, regard the operator $$L$$ as a compact perturbation of the operator div.
This book presents results on boundary-value problems for $$L$$ and the theory of nonlinear perturbations of $$L$$. Specifically, necessary and sufficient solvability conditions in explicit form are found for various boundary-value problems for the operator $$L$$. An analog of the Weyl decomposition is proved.
The book also contains a local description of the set of all solutions (located in a small neighborhood of a known solution) to the boundary-value problems for the nonlinear equation $$F(\dot y, y, x) = 0$$ for which $$L$$ is a linearization. A classification of sets of all solutions to various boundary-value problems for the nonlinear equation $$F(\dot y, y, x) = 0$$ is given.
The results are illustrated by various applications in geometry, the calculus of variations, physics, and continuum mechanics.
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https://hackage.haskell.org/package/diagrams-core-1.4.1/docs/Diagrams-Core-Envelope.html
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diagrams-core-1.4.1: Core libraries for diagrams EDSL
Diagrams.Core.Envelope
Description
diagrams-core defines the core library of primitives forming the basis of an embedded domain-specific language for describing and rendering diagrams.
The Diagrams.Core.Envelope module defines a data type and type class for "envelopes", aka functional bounding regions.
Synopsis
# Envelopes
newtype Envelope v n Source #
Every diagram comes equipped with an envelope. What is an envelope?
Consider first the idea of a bounding box. A bounding box expresses the distance to a bounding plane in every direction parallel to an axis. That is, a bounding box can be thought of as the intersection of a collection of half-planes, two perpendicular to each axis.
More generally, the intersection of half-planes in every direction would give a tight "bounding region", or convex hull. However, representing such a thing intensionally would be impossible; hence bounding boxes are often used as an approximation.
An envelope is an extensional representation of such a "bounding region". Instead of storing some sort of direct representation, we store a function which takes a direction as input and gives a distance to a bounding half-plane as output. The important point is that envelopes can be composed, and transformed by any affine transformation.
Formally, given a vector v, the envelope computes a scalar s such that
• for every point u inside the diagram, if the projection of (u - origin) onto v is s' *^ v, then s' <= s.
• s is the smallest such scalar.
There is also a special "empty envelope".
The idea for envelopes came from Sebastian Setzer; see http://byorgey.wordpress.com/2009/10/28/collecting-attributes/#comment-2030. See also Brent Yorgey, Monoids: Theme and Variations, published in the 2012 Haskell Symposium: http://ozark.hendrix.edu/~yorgey/pub/monoid-pearl.pdf; video: http://www.youtube.com/watch?v=X-8NCkD2vOw.
Constructors
Envelope (Option (v n -> Max n))
Instances
Show (Envelope v n) Source # MethodsshowsPrec :: Int -> Envelope v n -> ShowS #show :: Envelope v n -> String #showList :: [Envelope v n] -> ShowS # Ord n => Semigroup (Envelope v n) Source # Envelopes form a semigroup with pointwise maximum as composition. Hence, if e1 is the envelope for diagram d1, and e2 is the envelope for d2, then e1 mappend e2 is the envelope for d1 atop d2. Methods(<>) :: Envelope v n -> Envelope v n -> Envelope v n #sconcat :: NonEmpty (Envelope v n) -> Envelope v n #stimes :: Integral b => b -> Envelope v n -> Envelope v n # Ord n => Monoid (Envelope v n) Source # The special empty envelope is the identity for the Monoid instance. Methodsmempty :: Envelope v n #mappend :: Envelope v n -> Envelope v n -> Envelope v n #mconcat :: [Envelope v n] -> Envelope v n # Wrapped (Envelope v n) Source # Associated Typestype Unwrapped (Envelope v n) :: * # Methods_Wrapped' :: Iso' (Envelope v n) (Unwrapped (Envelope v n)) # (Metric v, Fractional n) => HasOrigin (Envelope v n) Source # The local origin of an envelope is the point with respect to which bounding queries are made, i.e. the point from which the input vectors are taken to originate. MethodsmoveOriginTo :: Point (V (Envelope v n)) (N (Envelope v n)) -> Envelope v n -> Envelope v n Source # (Metric v, Floating n) => Transformable (Envelope v n) Source # Methodstransform :: Transformation (V (Envelope v n)) (N (Envelope v n)) -> Envelope v n -> Envelope v n Source # (Metric v, OrderedField n) => Enveloped (Envelope v n) Source # MethodsgetEnvelope :: Envelope v n -> Envelope (V (Envelope v n)) (N (Envelope v n)) Source # (Metric v, OrderedField n) => Juxtaposable (Envelope v n) Source # Methodsjuxtapose :: Vn (Envelope v n) -> Envelope v n -> Envelope v n -> Envelope v n Source # Rewrapped (Envelope v n) (Envelope v' n') Source # type Unwrapped (Envelope v n) Source # type Unwrapped (Envelope v n) = Option (v n -> Max n) type N (Envelope v n) Source # type N (Envelope v n) = n type V (Envelope v n) Source # type V (Envelope v n) = v
appEnvelope :: Envelope v n -> Maybe (v n -> n) Source #
"Apply" an envelope by turning it into a function. Nothing is returned iff the envelope is empty.
onEnvelope :: ((v n -> n) -> v n -> n) -> Envelope v n -> Envelope v n Source #
A convenient way to transform an envelope, by specifying a transformation on the underlying v n -> n function. The empty envelope is unaffected.
mkEnvelope :: (v n -> n) -> Envelope v n Source #
Create an envelope from a v n -> n function.
pointEnvelope :: (Fractional n, Metric v) => Point v n -> Envelope v n Source #
Create a point envelope for the given point. A point envelope has distance zero to a bounding hyperplane in every direction. Note this is not the same as the empty envelope.
class (Metric (V a), OrderedField (N a)) => Enveloped a where Source #
Enveloped abstracts over things which have an envelope.
Minimal complete definition
getEnvelope
Methods
getEnvelope :: a -> Envelope (V a) (N a) Source #
Compute the envelope of an object. For types with an intrinsic notion of "local origin", the envelope will be based there. Other types (e.g. Trail) may have some other default reference point at which the envelope will be based; their instances should document what it is.
Instances
Enveloped b => Enveloped [b] Source # MethodsgetEnvelope :: [b] -> Envelope (V [b]) (N [b]) Source # Enveloped b => Enveloped (Set b) Source # MethodsgetEnvelope :: Set b -> Envelope (V (Set b)) (N (Set b)) Source # Enveloped t => Enveloped (TransInv t) Source # MethodsgetEnvelope :: TransInv t -> Envelope (V (TransInv t)) (N (TransInv t)) Source # (Enveloped a, Enveloped b, (~) (* -> *) (V a) (V b), (~) * (N a) (N b)) => Enveloped (a, b) Source # MethodsgetEnvelope :: (a, b) -> Envelope (V (a, b)) (N (a, b)) Source # Enveloped b => Enveloped (Map k b) Source # MethodsgetEnvelope :: Map k b -> Envelope (V (Map k b)) (N (Map k b)) Source # (OrderedField n, Metric v) => Enveloped (Point v n) Source # MethodsgetEnvelope :: Point v n -> Envelope (V (Point v n)) (N (Point v n)) Source # (Metric v, OrderedField n) => Enveloped (Envelope v n) Source # MethodsgetEnvelope :: Envelope v n -> Envelope (V (Envelope v n)) (N (Envelope v n)) Source # (OrderedField n, Metric v, Monoid' m) => Enveloped (Subdiagram b v n m) Source # MethodsgetEnvelope :: Subdiagram b v n m -> Envelope (V (Subdiagram b v n m)) (N (Subdiagram b v n m)) Source # (Metric v, OrderedField n, Monoid' m) => Enveloped (QDiagram b v n m) Source # MethodsgetEnvelope :: QDiagram b v n m -> Envelope (V (QDiagram b v n m)) (N (QDiagram b v n m)) Source #
# Utility functions
diameter :: (V a ~ v, N a ~ n, Enveloped a) => v n -> a -> n Source #
Compute the diameter of a enveloped object along a particular vector. Returns zero for the empty envelope.
radius :: (V a ~ v, N a ~ n, Enveloped a) => v n -> a -> n Source #
Compute the "radius" (1/2 the diameter) of an enveloped object along a particular vector.
extent :: (V a ~ v, N a ~ n, Enveloped a) => v n -> a -> Maybe (n, n) Source #
Compute the range of an enveloped object along a certain direction. Returns a pair of scalars (lo,hi) such that the object extends from (lo *^ v) to (hi *^ v). Returns Nothing for objects with an empty envelope.
size :: (V a ~ v, N a ~ n, Enveloped a, HasBasis v) => a -> v n Source #
The smallest positive axis-parallel vector that bounds the envelope of an object.
envelopeVMay :: Enveloped a => Vn a -> a -> Maybe (Vn a) Source #
Compute the vector from the local origin to a separating hyperplane in the given direction, or Nothing for the empty envelope.
envelopeV :: Enveloped a => Vn a -> a -> Vn a Source #
Compute the vector from the local origin to a separating hyperplane in the given direction. Returns the zero vector for the empty envelope.
envelopePMay :: (V a ~ v, N a ~ n, Enveloped a) => v n -> a -> Maybe (Point v n) Source #
Compute the point on a separating hyperplane in the given direction, or Nothing for the empty envelope.
envelopeP :: (V a ~ v, N a ~ n, Enveloped a) => v n -> a -> Point v n Source #
Compute the point on a separating hyperplane in the given direction. Returns the origin for the empty envelope.
envelopeSMay :: (V a ~ v, N a ~ n, Enveloped a) => v n -> a -> Maybe n Source #
Equivalent to the norm of envelopeVMay:
envelopeSMay v x == fmap norm (envelopeVMay v x)
(other than differences in rounding error)
Note that the envelopeVMay / envelopePMay functions above should be preferred, as this requires a call to norm. However, it is more efficient than calling norm on the results of those functions.
envelopeS :: (V a ~ v, N a ~ n, Enveloped a) => v n -> a -> n Source #
Equivalent to the norm of envelopeV:
envelopeS v x == norm (envelopeV v x)
(other than differences in rounding error)
Note that the envelopeV / envelopeP functions above should be preferred, as this requires a call to norm. However, it is more efficient than calling norm on the results of those functions.
# Miscellaneous
class (Floating s, Ord s) => OrderedField s Source #
When dealing with envelopes we often want scalars to be an ordered field (i.e. support all four arithmetic operations and be totally ordered) so we introduce this class as a convenient shorthand.
Instances
(Floating s, Ord s) => OrderedField s Source #
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http://mathhelpforum.com/trigonometry/69161-trig-identity-help.html
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1. ## Trig Identity Help
I am in gr.11 just starting trig identities. I have finished all of my hw except for one question. Which looks to me like it should be simple. I just can't seem to do it. haha i'm probably just being blonde but i'll keep trying! Thanks!
2. Originally Posted by DaCoo911
I am in gr.11 just starting trig identities. I have finished all of my hw except for one question. Which looks to me like it should be simple. I just can't seem to do it. haha i'm probably just being blonde but i'll keep trying! Thanks!
$\text{LHS }= \csc^2(x) + \sec^2(x) = \frac{1}{\sin^2(x)} + \frac{1}{\cos^2(x)}$
$= \frac{\cos^2(x)}{\sin^2(x)\cos^2(x)} + \frac{\sin^2(x)}{\sin^2(x)\cos^2(x)}$
$= \frac{\cos^2(x) + \sin^2(x)}{\sin^2(x)\cos^2(x)}$
$= \frac{1}{\sin^2(x)\cos^2(x)}$
$= \csc^2(x)\sec^2(x) = \text{RHS}$
3. Originally Posted by DaCoo911
I am in gr.11 just starting trig identities. I have finished all of my hw except for one question. Which looks to me like it should be simple. I just can't seem to do it. haha i'm probably just being blonde but i'll keep trying! Thanks!
$\csc^2{x} + \sec^2{x} = \frac{1}{\sin^2{x}} + \frac{1}{\cos^2{x}}$
$= \frac{\cos^2{x}}{\sin^2{x}\cos^2{x}} + \frac{\sin^2{x}}{\sin^2{x}\cos^2{x}}$
$= \frac{\cos^2{x} + \sin^2{x}}{\sin^2{x}\cos^2{x}}$
$= \frac{1}{\sin^2{x}\cos^2{x}}$
$= \csc^2{x}\sec^2{x}$.
4. Originally Posted by Prove It
$\csc^2{x} + \sec^2{x} = \frac{1}{\sin^2{x}} + \frac{1}{\cos^2{x}}$
$= \frac{\cos^2{x}}{\sin^2{x}\cos^2{x}} + \frac{\sin^2{x}}{\sin^2{x}\cos^2{x}}$
$= \frac{\cos^2{x} + \sin^2{x}}{\sin^2{x}\cos^2{x}}$
$= \frac{1}{\sin^2{x}\cos^2{x}}$
$= \csc^2{x}\sec^2{x}$.
Did you just c&p my post :P?
Identical!
Your coding and lack of parenthesis saves you from fraud! :P.
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https://inginious.org/course/portes_ouvertes/FirstSum
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Information
In programming, one of the first exercise asked for practice is to calculate the sum of the n first positive integers. It is to illustrate the capacity to repeat a process easily and with a few lines of computers.
To do so, use a for loop with a range.
x = ... #the number
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https://byjus.com/rd-sharma-solutions/class-8-maths-chapter-7-factorization-exercise-7-3/?replytocom=30974
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# RD Sharma Solutions for Class 8 Chapter - 7 Factorization Exercise 7.3
### RD Sharma Class 8 Solutions Chapter 7 Ex 7.3 PDF Free Download
Students can refer to RD Sharma Solutions for Class 8 Maths Exercise 7.3 Chapter 7 Factorization which are available here. The solutions here are solved step by step for a better understanding of the concepts, which helps students prepare for their exams at ease. Keeping in mind expert tutors at BYJU’S have made this possible to help students crack difficult problems. Students can download the pdf of RD Sharma Solutions from the links provided below.
Exercise 7.3 of Chapter 7 Factorization is on based on the factorization of algebraic expressions when a binomial is a common factor.
## Download the pdf of RD Sharma For Class 8 Maths Exercise 7.3 Chapter 7 Factorization
### Access Answers to RD Sharma Solutions for Class 8 Maths Exercise 7.3 Chapter 7 Factorization
Factorize each of the following algebraic expressions:
1. 6x (2x – y) + 7y (2x – y)
Solution:
We have,
6x (2x – y) + 7y (2x – y)
By taking (2x – y) as common we get,
(6x + 7y) (2x – y)
2. 2r (y – x) + s (x – y)
Solution:
We have,
2r (y – x) + s (x – y)
By taking (-1) as common we get,
-2r (x – y) + s (x – y)
By taking (x – y) as common we get,
(x – y) (-2r + s)
(x – y) (s – 2r)
3. 7a (2x – 3) + 3b (2x – 3)
Solution:
We have,
7a (2x – 3) + 3b (2x – 3)
By taking (2x – 3) as common we get,
(7a + 3b) (2x – 3)
4. 9a (6a – 5b) – 12a2 (6a – 5b)
Solution:
We have,
9a (6a – 5b) – 12a2 (6a – 5b)
By taking (6a – 5b) as common we get,
(9a – 12a2) (6a – 5b)
3a(3 – 4a) (6a – 5b)
5. 5 (x – 2y)2 + 3 (x – 2y)
Solution:
We have,
5 (x – 2y)2 + 3 (x – 2y)
By taking (x – 2y) as common we get,
(x – 2y) [5 (x – 2y) + 3]
(x – 2y) (5x – 10y + 3)
6. 16 (2l – 3m)2 – 12 (3m – 2l)
Solution:
We have,
16 (2l – 3m)2 – 12 (3m – 2l)
By taking (-1) as common we get,
16 (2l – 3m)2 + 12 (2l – 3m)
By taking 4(2l – 3m) as common we get,
4(2l – 3m) [4 (2l – 3m) + 3]
4(2l – 3m) (8l – 12m + 3)
7. 3a (x – 2y) – b (x – 2y)
Solution:
We have,
3a (x – 2y) – b (x – 2y)
By taking (x – 2y) as common we get,
(3a – b) (x – 2y)
8. a2 (x + y) + b2 (x + y) + c2 (x + y)
Solution:
We have,
a2 (x + y) + b2 (x + y) + c2 (x + y)
By taking (x + y) as common we get,
(a2 + b2 + c2) (x + y)
9. (x – y)2 + (x – y)
Solution:
We have,
(x – y)2 + (x – y)
By taking (x – y) as common we get,
(x – y) (x – y + 1)
10. 6 (a + 2b) – 4 (a + 2b)2
Solution:
We have,
6 (a + 2b) – 4 (a + 2b)2
By taking (a + 2b) as common we get,
[6 – 4 (a + 2b)] (a + 2b)
(6 – 4a – 8b) (a + 2b)
2(3 – 2a – 4b) (a + 2b)
11. a (x – y) + 2b (y – x) + c (x – y)2
Solution:
We have,
a (x – y) + 2b (y – x) + c (x – y)2
By taking (-1) as common we get,
a (x – y) – 2b (x – y) + c (x – y)2
By taking (x – y) as common we get,
[a – 2b + c(x – y)] (x – y)
(x – y) (a – 2b + cx – cy)
12. -4 (x – 2y)2 + 8 (x – 2y)
Solution:
We have,
-4 (x – 2y)2 + 8 (x – 2y)
By taking 4(x – 2y) as common we get,
[-(x – 2y) + 2] 4(x – 2y)
4(x – 2y) (-x + 2y + 2)
13. x3 (a – 2b) + x2 (a – 2b)
Solution:
We have,
x3 (a – 2b) + x2 (a – 2b)
By taking x2 (a – 2b) as common we get,
(x + 1) [x2 (a – 2b)]
x2 (a – 2b) (x + 1)
14. (2x – 3y) (a + b) + (3x – 2y) (a + b)
Solution:
We have,
(2x – 3y) (a + b) + (3x – 2y) (a + b)
By taking (a + b) as common we get,
(a + b) [(2x – 3y) + (3x – 2y)]
(a + b) [2x -3y + 3x – 2y]
(a + b) [5x – 5y]
(a + b) 5(x – y)
15. 4(x + y) (3a – b) + 6(x + y) (2b – 3a)
Solution:
We have,
4(x + y) (3a – b) + 6(x + y) (2b – 3a)
By taking (x + y) as common we get,
(x + y) [4(3a – b) + 6(2b – 3a)]
(x + y) [12a – 4b + 12b – 18a]
(x + y) [-6a + 8b]
(x + y) 2(-3a + 4b)
(x + y) 2(4b – 3a)
#### 1 Comment
1. Soyel rana
wow! i am so happy and satisfied to use this guide means byju’s learning app
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http://conceptmap.cfapps.io/wikipage?lang=en&name=Greisen%E2%80%93Zatsepin%E2%80%93Kuzmin_limit
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# Greisen–Zatsepin–Kuzmin limit
The Greisen–Zatsepin–Kuzmin limit (GZK limit) is a theoretical upper limit on the energy of cosmic ray protons traveling from other galaxies through the intergalactic medium to our galaxy. The limit is 5×1019 eV, or about 8 joules (the energy of a proton travelling at ~99.99999999999999999998% the speed of light). The limit is set by slowing interactions of the protons with the microwave background radiation over long distances (~160 million light-years). The limit is at the same order of magnitude as the upper limit for energy at which cosmic rays have experimentally been detected. For example, one extreme-energy cosmic ray, the Oh-My-God Particle, which has been found to possess a record-breaking 3.12×1020 eV (50 joules)[1][2] of energy (about the same as the kinetic energy of a 95 km/h baseball).
The GZK limit is derived under the assumption that ultra-high energy cosmic rays are protons. Measurements by the largest cosmic-ray observatory, the Pierre Auger Observatory, suggest that most ultra-high energy cosmic rays are heavier elements.[3] In this case, the argument behind the GZK limit does not apply in the originally simple form, and there is no fundamental contradiction in observing cosmic rays with energies that violate the limit.
In the past, the apparent violation of the GZK limit has inspired cosmologists and theoretical physicists to suggest other ways that circumvent the limit. These theories propose that ultra-high energy cosmic rays are produced nearby our galaxy or that Lorentz covariance is violated in such a way that protons do not lose energy on their way to our galaxy.
## Computation
The limit was independently computed in 1966 by Kenneth Greisen,[4] Vadim Kuzmin, and Georgiy Zatsepin,[5] based on interactions between cosmic rays and the photons of the cosmic microwave background radiation (CMB). They predicted that cosmic rays with energies over the threshold energy of 5×1019 eV would interact with cosmic microwave background photons ${\displaystyle \gamma _{\rm {CMB}}}$ , relatively blueshifted by the speed of the cosmic rays, to produce pions through the ${\displaystyle \Delta }$ resonance,
${\displaystyle \gamma _{\text{CMB}}+p\to \Delta ^{+}\to p+\pi ^{0},}$
or
${\displaystyle \gamma _{\text{CMB}}+p\to \Delta ^{+}\to n+\pi ^{+}.}$
Pions produced in this manner proceed to decay in the standard pion channels—ultimately to photons for neutral pions, and photons, positrons, and various neutrinos for positive pions. Neutrons decay also to similar products, so that ultimately the energy of any cosmic ray proton is drained off by production of high-energy photons plus (in some cases) high-energy electron–positron pairs and neutrino pairs.
The pion production process begins at a higher energy than ordinary electron-positron pair production (lepton production) from protons impacting the CMB, which starts at cosmic-ray proton energies of only about 1017 eV. However, pion production events drain 20% of the energy of a cosmic-ray proton as compared with only 0.1% of its energy for electron–positron pair production. This factor of 200 is from two sources: the pion has only about ~130 times the mass of the leptons, but the extra energy appears as different kinetic energies of the pion or leptons and results in relatively more kinetic energy transferred to a heavier product pion, in order to conserve momentum. The much larger total energy losses from pion production result in the pion production process becoming the limiting one to high-energy cosmic-ray travel, rather than the lower-energy light-lepton production process.
The pion production process continues until the cosmic ray energy falls below the pion production threshold. Due to the mean path associated with this interaction, extragalactic cosmic rays traveling over distances larger than 50 Mpc (163 Mly) and with energies greater than this threshold should never be observed on Earth. This distance is also known as GZK horizon.
Unsolved problem in physics:Why is it that some cosmic rays appear to possess energies that are theoretically too high, given that there are no possible near-Earth sources, and that rays from distant sources should have scattered by the cosmic microwave background radiation?(more unsolved problems in physics)
A number of observations have been made by the largest cosmic-ray experiments Akeno Giant Air Shower Array, High Resolution Fly's Eye Cosmic Ray Detector, the Pierre Auger Observatory and Telescope Array Project that appeared to show cosmic rays with energies above this limit (called extreme-energy cosmic rays, or EECRs). The observation of these particles was the so-called GZK paradox or cosmic-ray paradox.
These observations appear to contradict the predictions of special relativity and particle physics as they are presently understood. However, there are a number of possible explanations for these observations that may resolve this inconsistency.
• The observations could be due to an instrument error or an incorrect interpretation of the experiment, especially wrong energy assignment.
• The cosmic rays could have local sources well within the GZK horizon (although it is unclear what these sources could be).
### Weakly interacting particles
Another suggestion involves ultra-high-energy weakly interacting particles (for instance, neutrinos), which might be created at great distances and later react locally to give rise to the particles observed. In the proposed Z-burst model, an ultra-high-energy cosmic neutrino collides with a relic anti-neutrino in our galaxy and annihilates to hadrons.[6] This process proceeds through a (virtual) Z-boson:
${\displaystyle \nu +{\bar {\nu }}\to Z\to {\text{hadrons}}.}$
The cross-section for this process becomes large if the center-of-mass energy of the neutrino antineutrino pair is equal to the Z-boson mass (such a peak in the cross-section is called "resonance"). Assuming that the relic anti-neutrino is at rest, the energy of the incident cosmic neutrino has to be
${\displaystyle E={\frac {m_{Z}^{2}}{2m_{\nu }}}=4.2\times 10^{21}\left({\frac {\text{eV}}{m_{\nu }}}\right)~{\text{eV}},}$
where ${\displaystyle m_{Z}}$ is the mass of the Z-boson, and ${\displaystyle m_{\nu }}$ the mass of the neutrino.
### Other theories
A number of exotic theories have been advanced to explain the AGASA observations, including doubly special relativity. However, it is now established that standard doubly special relativity does not predict any GZK suppression (or GZK cutoff), contrary to models of Lorentz symmetry violation involving an absolute rest frame.[citation needed] Other possible theories involve a relation with dark matter, decays of exotic super-heavy particles beyond those known in the Standard Model.
## Controversy about cosmic rays above the GZK limit
A suppression of the cosmic-ray flux that can be explained with the GZK limit has been confirmed by the latest generation of cosmic-ray observatories. A former claim by the AGASA experiment that there is no suppression was overruled. It remains controversial whether the suppression is due to the GZK effect. The GZK limit only applies if ultra-high-energy cosmic rays are mostly protons.
In July 2007, during the 30th International Cosmic Ray Conference in Mérida, Yucatán, México, the High Resolution Fly's Eye Experiment (HiRes) and the Pierre Auger Observatory (Auger) presented their results on ultra-high-energy cosmic rays. HiRes observed a suppression in the UHECR spectrum at just the right energy, observing only 13 events with an energy above the threshold, while expecting 43 with no suppression. This was interpreted as the first observation of the GZK limit.[7] Auger confirmed the flux suppression, but did not claim it to be the GZK limit: instead of the 30 events necessary to confirm the AGASA results, Auger saw only two, which are believed to be heavy-nuclei events.[8] The flux suppression was previously brought into question when the AGASA experiment found no suppression in their spectrum[citation needed]. According to Alan Watson, spokesperson for the Auger Collaboration, AGASA results have been shown to be incorrect, possibly due to the systematic shift in energy assignment.
In 2010 and the following years, both the Pierre Auger Observatory and HiRes confirmed again a flux suppression,[9][10] in case of the Pierre Auger Observatory the effect is statistically significant at the level of 20 standard deviations.
After the flux suppression was established, a heated debate ensued whether cosmic rays that violate the GZK limit are protons. The Pierre Auger Observatory, the world's largest observatory, found with high statistical significance that ultra-high-energy cosmic rays are not purely protons, but a mixture of elements, which is getting heavier with increasing energy.[3] The Telescope Array Project, a joint effort from members of the HiRes and AGASA collaborations, agrees with the former HiRes result that these cosmic rays look like protons.[11] The claim is based on data with lower statistical significance, however. The area covered by Telescope Array is about one third of the area covered by the Pierre Auger Observatory, and the latter has been running for a longer time.
The controversy was partially resolved in 2017, when a joint working group formed by members of both experiments presented a report at the 35th International Cosmic Ray Conference.[12] According to the report, the raw experimental results are not in contradiction with each other. The different interpretations are mainly based on the use of different theoretical models (Telescope Array uses an outdated model for its interpretation) and the fact that Telescope Array has not collected enough events yet to distinguish the pure-proton hypothesis from the mixed-nuclei hypothesis.
### Extreme Universe Space Observatory on Japanese Experiment Module (JEM-EUSO)
EUSO, which was scheduled to fly on the International Space Station (ISS) in 2009, was designed to use the atmospheric-fluorescence technique to monitor a huge area and boost the statistics of UHECRs considerably. EUSO is to make a deep survey of UHECR-induced extensive air showers (EASs) from space, extending the measured energy spectrum well beyond the GZK cutoff. It is to search for the origin of UHECRs, determine the nature of the origin of UHECRs, make an all-sky survey of the arrival direction of UHECRs, and seek to open the astronomical window on the extreme-energy universe with neutrinos. The fate of the EUSO Observatory is still unclear, since NASA is considering early retirement of the ISS.
### The Fermi Gamma-ray Space Telescope to resolve inconsistencies
Launched in June 2008, the Fermi Gamma-ray Space Telescope (formerly GLAST) will also provide data that will help resolve these inconsistencies.
• With the Fermi Gamma-ray Space Telescope, one has the possibility of detecting gamma rays from the freshly accelerated cosmic-ray nuclei at their acceleration site (the source of the UHECRs).[13]
• UHECR protons accelerated (see also Centrifugal mechanism of acceleration) in astrophysical objects produce secondary electromagnetic cascades during propagation in the cosmic microwave and infrared backgrounds, of which the GZK process of pion production is one of the contributors. Such cascades can contribute between about 1% and 50% of the GeV–TeV diffuse photon flux measured by the EGRET experiment. The Fermi Gamma-ray Space Telescope may discover this flux.[14]
## Possible sources of UHECRs
In November 2007, researchers at the Pierre Auger Observatory announced that they had evidence that UHECRs appear to come from the active galactic nuclei (AGNs) of energetic galaxies powered by matter swirling onto a supermassive black hole. The cosmic rays were detected and traced back to the AGNs using the Véron-Cetty-Véron catalog. These results are reported in the journal Science.[15] Nevertheless, the strength of the correlation with AGNs from this particular catalog for the Auger data recorded after 2007 has been slowly diminishing.[16]
## References
1. ^ "HiRes - The High Resolution Fly's Eye Ultra High Energy Cosmic Ray Observatory". www.cosmic-ray.org. Retrieved 2019-06-13.
2. ^ "Oh-My-God Particles". phys.org. Retrieved 2019-06-13.
3. ^ a b The Pierre Auger Collaboration (2017). "Inferences on Mass Composition and Tests of Hadronic Interactions from 0.3 to 100 EeV using the water-Cherenkov Detectors of the Pierre Auger Observatory". arXiv:1710.07249 [astro-ph.HE].
4. ^ Greisen, Kenneth (1966). "End to the Cosmic-Ray Spectrum?". Physical Review Letters. 16 (17): 748–750. Bibcode:1966PhRvL..16..748G. doi:10.1103/PhysRevLett.16.748.
5. ^ Zatsepin, G. T.; Kuz'min, V. A. (1966). "Upper Limit of the Spectrum of Cosmic Rays" (PDF). Journal of Experimental and Theoretical Physics Letters. 4: 78–80. Bibcode:1966JETPL...4...78Z.
6. ^ Fargion, D.; Mele, B.; Salis, A. (June 1999). "Ultra–High‐Energy Neutrino Scattering onto Relic Light Neutrinos in the Galactic Halo as a Possible Source of the Highest Energy Extragalactic Cosmic Rays". The Astrophysical Journal. 517 (2): 725–733. arXiv:astro-ph/9710029. Bibcode:1999ApJ...517..725F. doi:10.1086/307203.
7. ^ Abbasi, R. U.; et al. (2008). "First Observation of the Greisen-Zatsepin-Kuzmin Suppression". Physical Review Letters. 100 (10): 101101. arXiv:astro-ph/0703099. Bibcode:2008PhRvL.100j1101A. doi:10.1103/PhysRevLett.100.101101. PMID 18352170.
8. ^ Abraham, J.; et al. (2008). "Observation of the suppression of the flux of cosmic rays above 4×1019 eV". Physical Review Letters. 101 (6): 061101–1–061101–7. arXiv:0806.4302. Bibcode:2008PhRvL.101f1101A. doi:10.1103/PhysRevLett.101.061101. PMID 18764444.
9. ^ The Pierre Auger Collaboration (2010). "Measurement of the energy spectrum of cosmic rays above 1018 eV using the Pierre Auger Observatory". Phys. Lett. B. 685 (4–5): 239–246. arXiv:1002.1975. Bibcode:2010PhLB..685..239A. doi:10.1016/j.physletb.2010.02.013.
10. ^ Sokolsky; for the HiRes Collaboration (2010). "Final Results from the High Resolution Fly's Eye (HiRes) Experiment". Nuclear Physics B: Proceedings Supplements. 212–213: 74–78. arXiv:1010.2690. doi:10.1016/j.nuclphysbps.2011.03.010.
11. ^ Hanlon, William; others (2017). "Telescope Array Composition Summary". PoS. 301 (536): 536. Bibcode:2017ICRC...35..536H.
12. ^ de Souza, Vitor; others (2017). "Testing the agreement between the Xmax distributions measured by the Pierre Auger and Telescope Array Observatories". PoS. 301 (522).
13. ^ Ormes, Jonathan F.; et al. (2000). "The origin of cosmic rays: What can the Fermi Gamma-ray Telescope say?". AIP Conference Proceedings. 528: 445–448. arXiv:astro-ph/0003270. doi:10.1063/1.1324357.
14. ^ Kalashev, Oleg E.; Semikoz, Dmitry V.; Sigl, Guenter (2009). "Ultra-High Energy Cosmic Rays and the GeV–TeV Diffuse Gamma-Ray Flux". Physical Review D. 79 (6): 063005. arXiv:0704.2463. Bibcode:2009PhRvD..79f3005K. doi:10.1103/PhysRevD.79.063005.
15. ^ The Pierre Auger Collaboration (2007). "Correlation of the Highest-Energy Cosmic Rays with Nearby Extragalactic Objects". Science. 318 (5852): 938–943. arXiv:0711.2256. Bibcode:2007Sci...318..938P. doi:10.1126/science.1151124. PMID 17991855.
16. ^ The Pierre Auger Collaboration (2010). "Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter". Astropart. Phys. 34 (5): 314–326. arXiv:1009.1855. Bibcode:2010APh....34..314A. doi:10.1016/j.astropartphys.2010.08.010.
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http://math.stackexchange.com/questions/293639/butcher-tableau-for-given-algorithm
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butcher tableau for given algorithm
Given $y'(t) = f(t,y(t))$ and the following algorithm:
$$y_{n+\frac{1}{2}} = y_n + \frac{h}{2}f(t_n,y_n)$$ $$y_{n+1} = y_n + hf(t_n+\frac{h}{2},y_{n+\frac{1}{2}})$$
We should show that this can be seen as an explicit runge kutta algorithm (how to exactly do this?) and determine the butcher tableu.
I somehow compared this to the usual form in which an runge kutte algorithm is given and think the tableu must be
$$\begin{array}{c|cc} 0 & 0 & 0 \\ \frac{1}{2} & \frac{1}{2} & 0 \\ \hline & 0 & 1 \\ \end{array}$$
-
Try to reformulate your two equation by substituting $y_{n+1/2}$ in the second equation with the first equation to obtain an expression of the form, given in the reference: en.wikipedia.org/wiki/… – sonystarmap Feb 4 '13 at 8:58
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https://docs.dgl.ai/en/0.8.x/generated/dgl.nn.tensorflow.conv.SGConv.html
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# SGConv¶
class dgl.nn.tensorflow.conv.SGConv(in_feats, out_feats, k=1, cached=False, bias=True, norm=None, allow_zero_in_degree=False)[source]
Bases: tensorflow.python.keras.engine.base_layer.Layer
SGC layer from Simplifying Graph Convolutional Networks
$H^{K} = (\tilde{D}^{-1/2} \tilde{A} \tilde{D}^{-1/2})^K X \Theta$
where $$\tilde{A}$$ is $$A$$ + $$I$$. Thus the graph input is expected to have self-loop edges added.
Parameters
• in_feats (int) – Number of input features; i.e, the number of dimensions of $$X$$.
• out_feats (int) – Number of output features; i.e, the number of dimensions of $$H^{K}$$.
• k (int) – Number of hops $$K$$. Defaults:1.
• cached (bool) –
If True, the module would cache
$(\tilde{D}^{-\frac{1}{2}}\tilde{A}\tilde{D}^{-\frac{1}{2}})^K X\Theta$
at the first forward call. This parameter should only be set to True in Transductive Learning setting.
• bias (bool) – If True, adds a learnable bias to the output. Default: True.
• norm (callable activation function/layer or None, optional) – If not None, applies normalization to the updated node features. Default: False.
• allow_zero_in_degree (bool, optional) – If there are 0-in-degree nodes in the graph, output for those nodes will be invalid since no message will be passed to those nodes. This is harmful for some applications causing silent performance regression. This module will raise a DGLError if it detects 0-in-degree nodes in input graph. By setting True, it will suppress the check and let the users handle it by themselves. Default: False.
Note
Zero in-degree nodes will lead to invalid output value. This is because no message will be passed to those nodes, the aggregation function will be appied on empty input. A common practice to avoid this is to add a self-loop for each node in the graph if it is homogeneous, which can be achieved by:
>>> g = ... # a DGLGraph
Calling add_self_loop will not work for some graphs, for example, heterogeneous graph since the edge type can not be decided for self_loop edges. Set allow_zero_in_degree to True for those cases to unblock the code and handle zero-in-degree nodes manually. A common practise to handle this is to filter out the nodes with zero-in-degree when use after conv.
Example
>>> import dgl
>>> import numpy as np
>>> import tensorflow as tf
>>> from dgl.nn import SGConv
>>>
>>> with tf.device("CPU:0"):
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
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https://worldwidescience.org/topicpages/b/bispectral+index+monitoring.html
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#### Sample records for bispectral index monitoring
1. MONITORING DEPTH OF ANAESTHESIA USING PRST SCORE AND BISPECTRAL INDEX
Directory of Open Access Journals (Sweden)
Rahul
2015-03-01
Full Text Available BACKGROUND : Intraoperative awareness is a frightening experience for any patient for it has long term psychological consequences. Among the various tools available for monitoring depth of anaesthesia, Bispectral index monitoring (BIS is one of the recent and widely accepted techniques. AIMS AND OBJECTIVES : The present study was carried out to evaluate and correlate the efficacy of BIS monitoring along with PRST score in assessment of depth of anaesthesia. MATERIALS AND METHODS : A prospective clinical study was conducted on 160 patients undergoing surgery in various specialties, in the department of Anaesthesiology at Rajarajeswari Medical College and Hospital which included adult patients between the ages of 18 and 65 years and of ASA I/II posted for elective surgeries under general anaesthesia. Conditions and drugs likely to interfere with BIS values were excluded. Anaesthesia protocol was kept uniform. These patients were divided into two groups of 80 patients each by consecutive selection. In Group 1 - depth of anaesthesia was assessed by PRST score, in Group 2 - by BIS monitoring and PRST score. Statistical analysis was performed by descriptive statistics to calculate the mean and standard deviation, the t - test, χ² test s for calculating the materiality for establishing the results. RESULTS: We saw that the Bispectral index varied with various stages of anaesthesia, almost simultaneous changes in systolic, diastolic and mean arterial blood pressures occurred in both groups in T1 and T2. On intubation, both blood pressure and heart rate increased but BIS showed a very minimal increase, which was because of adequate depth of anaesthesia and analgesia . There was a statistically significant difference in PRST scores between the two groups. There was no incidence of awareness among our study population. CONCLUSION : Evaluation of intraoperative depth of anaesthesia is one of the major tasks of anaesthesiologist. In patients with higher
2. Bispectral index monitoring to facilitate early extubation following cardiovascular surgery.
Science.gov (United States)
Anderson, Jennifer; Henry, Linda; Hunt, Sharon; Ad, Niv
2010-01-01
Frequently, intensive care nurses assume responsibility for extubating patients after undergoing cardiac surgery. Bispectral index (BIS) monitoring assesses level of mental arousal and awareness when sedated. This study was to determine if the BIS might facilitate earlier extubation of patients following cardiac surgery. A study was conducted comparing 25 stable patients returning to the intensive care unit with a BIS with 25 patients managed without the BIS (N = 50). Data collected included age, sex, surgery, pH, CO2, and temperature on arrival/extubation, total intravenous propofol and pain medication, and BIS scores. Student t tests determined that there were no differences between groups for age, amount of propofol and pain medication received, or time to extubation (P > .05). Regression analysis determined that total propofol, total hydromorphone, and age were significant predictors of time to extubation. In this study, the BIS monitor did not facilitate earlier extubation in the stable patient after cardiac surgery. PMID:20404622
3. Auditory information processing during adequate propofol anesthesia monitored by electroencephalogram bispectral index
NARCIS (Netherlands)
C. Kerssens (Chantal); J. Klein (Jan); A. van der Woerd; B. Bonke (Benno)
2001-01-01
textabstractMemory for intraoperative events may arise from inadequate anesthesia when the hypnotic state is not continuously monitored. Electroencephalogram bispectral index (BIS) enables monitoring of the hypnotic state and titration of anesthesia to an adequate level
4. Bispectral Index Monitoring in Guillain Barre Syndrome with Dysautonomia
OpenAIRE
Deepak Sharma; Virendra Jain; Rath, Girija P; Parmod K Bithal
2008-01-01
Bispectral index (BIS) is commonly used as an index of depth of anaesthesia and sedation. BIS can provide an additional benefit in detecting a critical neurological event, especially if the change of neurological status is caused by the critical illness itself. We encountered such an incident where the BIS value was decreased in a patient with Guillain Barre Syndrome, possibly due to cerebral hypoperfusion. The present report emphasises that BIS can be used not only as an indicator of cerebra...
5. Bispectral index monitoring of sedation depth in pediatric dental patients.
Science.gov (United States)
Haberland, Christel M; Baker, Suher; Liu, Haibei
2011-01-01
The bispectral index (BIS) monitor records electroencephalogram waveforms and provides an objective measure of the hypnotic effect of a sedative drug on brain activity. The aim of this pilot study was to use the BIS monitor to evaluate the depth of procedural sedation in pediatric dental patients and to assess if the BIS monitor readings correlate with a validated pediatric sedation scale, the University of Michigan Sedation Scale (UMSS), in determining the level of sedation in these patients. Thirty-five pediatric dental patients requiring sedation were studied prospectively. A baseline BIS reading was obtained and during the procedure an independent observer recorded the BIS every 5 minutes. The operator, who was blinded to the BIS results, determined the UMSS scale at the same 5-minute interval. The patients were monitored postoperatively for 1 hour. There was a significant but moderate correlation between BIS values and UMSS scores (Spearman's rank correlation r = -0.574, P < .0001). Percentage of agreement and kappa coefficient using all the observations were also calculated. The percentage of agreement was 37.8%, the kappa coefficient was 0.18 (P < .0001), and the weighted kappa coefficient 0.26 (P < .0001). A lack of correlation was noted between the deeper levels of UMSS sedation scores and BIS values. This study demonstrated a significant correlation between BIS values and the UMSS score in pediatric dental patients undergoing mild to moderate sedation. Based on our results, it appears that the BIS monitor may be useful during mild or moderate sedations to establish the level of sedation objectively without the need to stimulate the patient. PMID:21679042
6. Bispectral Index Monitoring in Guillain Barre Syndrome with Dysautonomia
Directory of Open Access Journals (Sweden)
Deepak Sharma
2008-01-01
Full Text Available Bispectral index (BIS is commonly used as an index of depth of anaesthesia and sedation. BIS can provide an additional benefit in detecting a critical neurological event, especially if the change of neurological status is caused by the critical illness itself. We encountered such an incident where the BIS value was decreased in a patient with Guillain Barre Syndrome, possibly due to cerebral hypoperfusion. The present report emphasises that BIS can be used not only as an indicator of cerebral ischaemia, but also as a tool to judge adequacy and efficacy of interventions targeted to restore the same.
7. Effect of different doses of dezocine on degree of emergence agitation under bispectral index monitoring
Institute of Scientific and Technical Information of China (English)
Xing-Bao Liang; Zong-Rong Guo
2016-01-01
Objective:To analyze the effect of different doses of dezocine on degree of emergence agitation under bispectral index monitoring. Methods:A total of 196 cases who received general anesthesia in our hospital from September 2012 to December 2014 were selected as research subjects, bispectral index (BIS) monitoring was continuously conducted during anesthesia induction and extubation anesthesia recovery, and according to different methods of dezocine intervention, they were randomly divided into control group, D1 group, D2 group and D3 group, each group with 49 cases. Differences in levels of recovery time-related indexes, BIS values before dezocine administration (T0), sputum suction before extubation (T1), extubation time (T2) and 10 min after extubation (T3), hemodynamic indexes and stress indexes of all groups were compared. Results:Recovery time and extubation time of D2 group were shorter than those of control group, D1 group and D3 group, restlessness scale after extubation and VAS were lower than those of control group and D1 group, and Ramsay sedation scale was higher than that of control group and D1 group (P0.05);cortisol and blood glucose levels at T1, T2 and T3 points in time of D2 and D3 group were lower than those of other two groups (P0.05). Conclusions:0.1 mg/kg dezocine administration before end of operation can reduce emergence agitation without causing excessive sedation or prolonged extubation time, and it has active significance in stabilizing patients’ hemodynamic and stress levels in extubation period.
8. Changes in bilateral bispectral index VISTA monitoring system during Wada test.
Science.gov (United States)
Pacreu, S; Vila, E; Rodríguez, C; Arroyo, R; Fernández, S; Fernández, J L
2014-12-01
The Wada test is a procedure used in the preoperative assessment before epilepsy surgery in order to determine language lateralization, to assess the post-operative risk of an amnesia syndrome, and to evaluate the risk of material-specific memory deficits, in particular verbal memory deficits. This test involves inserting a cannula into the internal carotid artery via the femoral artery, and then to inject amobarbital to shut down brain function, usually in one of the brain hemispheres. The bilateral bispectral index (BIS) VISTA™ monitoring system (BVMS) was used to detect changes in EEG, and in the power spectrum distribution using the density spectral array (DSA) of both hemispheres. We describe a patient with an agenesis of the A1 segment of the right anterior cerebral artery, scheduled for a Wada test, in whom the BVMS demonstrated its potential value. PMID:24657004
9. Bispectral index monitoring during cardiopulmonary resuscitation repeated twice within 8 days in the same patient: a case report
OpenAIRE
Pawlik, Michael T.; Seyfried, Timo F.; Riegger, Christian; Klingler, Werner; Selig, Christoph
2008-01-01
Research on cardiac resuscitation has led to various changes in the techniques and drug administration involved in modern advanced life support. Besides improving primary cardiac survival, interest is increasingly focused on a favourable neurological outcome. However, until now there has been no on-site equipment to support the clinical observations of the cardiopulmonary resuscitation (CPR) team. Bispectral index (BIS) monitoring has been used for avoiding awareness during anaesthesia for ma...
10. Effect of bispectral index monitoring on desflurane consumption and recovery time in morbidly obese patients undergoing laparoscopic sleeve gastrectomy
OpenAIRE
Ibrahim, Tamer H.; Yousef, Gamal T.; Hasan, Ali M. Ali; Eldesuky, Hossam I.
2013-01-01
Background: Morbid obesity magnifies the importance of the fat–blood solubility coefficient of the anesthetic in its relation to emergence and recovery. Using bispectral index (BIS) monitoring for the titration of the administration of inhaled anesthetics such as desflurane may permit a less consumption and more rapid recovery from desflurane anesthesia in morbidly obese patients, which enables earlier maintenance of a patent airway, better protection against aspiration, and better oxygenatio...
11. Bispectral index monitoring for conscious sedation in intervention: better, safer, faster
Energy Technology Data Exchange (ETDEWEB)
Bell, J.K.; Laasch, H.-U.; Wilbraham, L.; England, R.E.; Morris, J.A.; Martin, D.F. E-mail: [email protected]
2004-12-01
AIM: The aim of this study was to compare subjective (Ramsay sedation score, RSS) with objective electroencephalogram-based bispectral index (BIS) assessment, and to validate the appropriate BIS range for measurement of conscious sedation in interventional procedures. MATERIALS AND METHODS: One hundred patients undergoing sedo-analgesia (midazolam and fentanyl) for interventional gastrointestinal procedures were divided into two groups. In group A (n=30) sedation was guided by the RSS with the operator blinded to the BIS recording. In group B (n=70) the operator titrated intravenous sedation to maintain an optimal BIS, predetermined from the results in group A. Recovery time, procedure duration, physiological parameters and unplanned events were recorded in both groups. RESULTS: There was a significant correlation between the BIS and RSS (p<0.001). BIS values of 87.2 and 80.9 corresponded to an RSS of 3 and 4, respectively. The optimal BIS level was defined as 80-85. Fifty-seven point five percent of readings were within this range in group B compared with 26.5% in group A (p<0.001). Sedation approaching general anaesthesia (BIS<60) occurred in 5.5% of patients in group A but not in group B. Mean recovery time, duration of procedure, midazolam and fentanyl doses were significantly reduced in group B. Unplanned events were reduced from 27 to 17%, but this was not statistically significant (p=0.29). CONCLUSION: BIS monitoring enables more effective titration of sedatives to maintain a suitable level of consciousness, whilst reducing procedure time. The BIS offers an objective, safe and reliable measure of sedation, without disturbing either patient or operator. BIS monitoring raises the standard of patient care, and in our view, should be used to augment standard assessment.
12. Bispectral index monitoring for conscious sedation in intervention: better, safer, faster
International Nuclear Information System (INIS)
AIM: The aim of this study was to compare subjective (Ramsay sedation score, RSS) with objective electroencephalogram-based bispectral index (BIS) assessment, and to validate the appropriate BIS range for measurement of conscious sedation in interventional procedures. MATERIALS AND METHODS: One hundred patients undergoing sedo-analgesia (midazolam and fentanyl) for interventional gastrointestinal procedures were divided into two groups. In group A (n=30) sedation was guided by the RSS with the operator blinded to the BIS recording. In group B (n=70) the operator titrated intravenous sedation to maintain an optimal BIS, predetermined from the results in group A. Recovery time, procedure duration, physiological parameters and unplanned events were recorded in both groups. RESULTS: There was a significant correlation between the BIS and RSS (p<0.001). BIS values of 87.2 and 80.9 corresponded to an RSS of 3 and 4, respectively. The optimal BIS level was defined as 80-85. Fifty-seven point five percent of readings were within this range in group B compared with 26.5% in group A (p<0.001). Sedation approaching general anaesthesia (BIS<60) occurred in 5.5% of patients in group A but not in group B. Mean recovery time, duration of procedure, midazolam and fentanyl doses were significantly reduced in group B. Unplanned events were reduced from 27 to 17%, but this was not statistically significant (p=0.29). CONCLUSION: BIS monitoring enables more effective titration of sedatives to maintain a suitable level of consciousness, whilst reducing procedure time. The BIS offers an objective, safe and reliable measure of sedation, without disturbing either patient or operator. BIS monitoring raises the standard of patient care, and in our view, should be used to augment standard assessment
Institute of Scientific and Technical Information of China (English)
Se Young Jang; Hyun Gu Park; Min Kyu Jung; Chang Min Cho; Soo Young Park; Seong Woo Jeon; Won Young Tak
2012-01-01
AIM:TO determine whether bispectral index (BIS)monitoring is useful for propofol administration for deep sedation during endoscopic retrograde cholangiopancreatography (ERCP).METHODS:Fifty-nine consecutive patients with a variety of reasons for ERCP who underwent the procedure at least twice between 1 July 2010 and 30 November 2010.This was a randomized cross-over study,in which each patient underwent ERCP twice,once with BIS monitoring and once with control monitoring.Whether BIS monitoring was done during the first or second ERCP procedure was random.Patients were intermittently administered a mixed regimen including midazolam,pethidine,and propofol by trained nurses.The nurse used a routine practice to monitor sedation using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale or the BIS monitoring.The total amount of midazolam and propofol used and serious side effects were compared between the BIS and control groups.RESULTS:The mean total propofol dose administered was 53.1 ± 32.2 mg in the BIS group and 54.9± 30.8 mg in the control group (P =0.673).The individual propofol dose received per minute during the ERCP procedure was 2.90 ± 1.83 mg/min in the BIS group and 3.44 ± 2.04 mg in the control group (P =0.103).The median value of the MOAA/S score during the maintenance phase of sedation was comparable for the two groups.The mean BIS values throughout the procedure (from insertion to removal of the endoscope) were 76.5 ± 8.7 for all 59 patients in using the BIS monitor.No significant differences in the frequency of ＜ 80％ oxygen saturation,hypotension (＜ 80 mmHg),or bradycardia (＜ 50 beats/min) were observed between the two study groups.Four cases of poor cooperation occurred,in which the procedure should be stopped to add the propofol dose.After adding the propofol,the procedure could be conducted successfully (one case in the BIS group,three cases in the control group).The endoscopist rated patient sedation as excellent for
14. Bispectral index monitoring in isoflurane anesthesia in laparoscopic cholecystectomy of morbid obese patients
OpenAIRE
2014-01-01
Background: Morbid obesity is associated with a some of significant comorbidities. Early and uneventful postoperative recovery of obese patients remains a challenge for anesthesiologists. It seems Bispecteral Index (BIS) monitoring may reduce drug usage and hasten recovery time in inhalation anesthesia. The aim of this study was to investigate the effect of BIS monitoring on intraoperative isoflurane utilization and the early recovery profile. Methods: Fifty morbidly obese adult patients (...
15. Awareness of bispectral index monitoring system among the critical care nursing personnel in a tertiary care hospital of India
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Shikha Thakur
2011-01-01
Full Text Available Background: Bispectral index monitoring system (BIS is one of the several systems used to measure the effects of anaesthetic and sedative drugs on the brain and to track changes in the patient′s level of sedation and hypnosis. BIS monitoring provides information clinically relevant to the adjustment of dosages of sedating medication. It can help the nursing personnel in preventing under- and over sedation among intensive care unit (ICU patients. Objective: The present study was conducted to assess the knowledge of nursing personnel working in the ICU regarding BIS. Methods: Fifty-four subjects participated in the study. A structured questionnaire was developed to assess the knowledge of the nursing personnel regarding BIS. Focus group discussions were held among the nursing personnel to know their views regarding BIS. Results: Mean age (years of the subjects was 30.77.19 (21-47 years, with a female preponderance. Although the use of BIS in ICU is not common, majority (94.44% were aware of BIS and its purpose. 79.62% of the subjects knew about its implication in patient care. The mean knowledge score of the subjects was 11.872.43 (maximum score being 15. Conclusion: There exists an awareness among the critical care nursing staff in our institution regarding BIS and its clinical implications. Its use in the critical care setting may benefit the patients in terms of providing optimal sedation.
16. [Application of bispectral index (BIS) monitoring to anesthetic management of posterior spinal fusion in a patient with Duchenne muscular dystrophy].
Science.gov (United States)
Abe, Maiko; Hayashi, Hideaki; Hayashi, Yukio; Mashimo, Takashi
2002-07-01
A 12-year-old boy with Duchenne muscular dystrophy underwent posterior spinal fusion for progressive scoliosis. Preoperative evaluation was focused on respiratory function as well as cardiac function, which revealed markedly reduced respiratory reserve (FVC 0.77 l, %FVC 25.9%, FEV1.0 0.48 l, %FEV1.0 62%) and well-preserved biventricular function. A possible association between malignant hyperthermia and Duchenne muscular dystrophy has been documented. Thus anesthesia was administered without triggering agents. Propofol and fentanyl were used for induction and maintenance of anesthesia, and the patient was ventilated with O2-nitrous oxide mixture. The anesthesia machine, prepared by using a disposable circuit and fresh CO2-absorbent and disconnecting the vaporizers, was flushed with O2 at a rate of 10 l.min-1 for 20 minutes before use. A small dose of vecuronium was administered while monitoring the train-of-four ratio. The bispectral index (BIS) was utilized to optimize the depth of anesthesia so that the wake-up test could be performed promptly on surgeon's request while avoiding the intraoperative awareness. The BIS was helpful in continuously assessing the wakening process. BIS increased from 40's to 80's in 15 minutes after discontinuation of propofol and nitrous oxide during the test. The patient was kept under close observation postoperatively without any sign of malignant hyperthermia. PMID:12166284
17. The Utility of Bispectral Index for Titration of Propofol Dosages and Recovery from Anaesthesia
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Heena Parikh
2012-08-01
Full Text Available Background: The use of clinical signs may not be reliable to measure the hypnotic component of anaesthesia. Bispectral Index monitoring provides a direct measurement of the hypnotic effect of the anaesthetic agent used and it may have certain clinical advantages over clinical signs. Objective: This study consists of dose requirement of propofol with bispectral Index monitoring and without bispectral Index monitoring. Material and Methods: In the present study, 100 patients were randomly divided into two groups (50 in each group, one group received Standard dose of propofol while the other received propofol infusion with BIS monitoring. Results: Mean amount of propofol for induction used was 1.6 vs 2.24 mg/kg in bispectral index group and standard group respectively. The inference was that the induction dose of propofol by Bispectral index and by standard practice was statistically highly significant with P<0.001. Similarly mean amount of propofol for maintenance used was 5.70 vs 8.88 mg/kg/hr in bispectral index group and standard group respectively. The inference was that the maintenance dose of propofol by Bispectral index and by standard practice was statistically highly significant with P<0.001. Conclusion: Dose requirement of propofol was less and early recovery from anesthesia with bispectral Index monitoring. [Natl J of Med Res 2012; 2(4.000: 484-487
18. Comparative evaluation of the cerebral state index/sup TM/ and bispectral index/sup TM/ monitoring during propofol-remifentanil anesthesia for open heart surgery
International Nuclear Information System (INIS)
The Cerebral State index (CSI) is a new index based on electroencephalogram to monitor depth of anesthesia. Transferring guidelines for titration of the Bispectral index (BIS) to the CSI depends on their compatibility. We compared the relationship between BIS and CSI values during propofol-remifentanil anesthesia. Forty one adult patients about to have open heart surgeries were enrolled. The skin was prepped and electrodes of both monitors were applied according to the manufacturers recommendations. The anesthesia was induced by midazolam, propofol, remifentanil and pancuronium and maintained by propofol and remifentanil and 50% nitrous oxide in oxygen. The BIS and CSI values were recorded in 37 pre-determined milestones during the operation and the anesthetic drugs were adjusted according to clinical signs of light anesthesia regardless of the CSI or BIS values. The BIS and CSI values decreased progressively from pre induction values of 93.15 (55-100) and 88.86 (52-100) to post induction values of 38.72 (16-71) and 40.27 (5-69), respectively. These values showed good linear correlation during laryngoscopy, before and after surgical incision and during CPB; R=0.695 with determination coefficient of 0.483. We found a good correlation between BIS and CSI values. Our results might serve as a blue print for a rational translation of BIS into CSI values. (author)
19. Relationship between type of brain injury with Bispectral Index monitoring in intubated ICU trauma patients
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2015-05-01
Conclusion: Different kinds of acute traumatic cranial lesions with different prognosis may have different values in BIS monitoring. Presence or absence of frontal lobe injury, had no statistically significant correlations with BIS values.
20. BiSpectral Index (BIS) monitoring may detect critical hypotension before automated non-invasive blood pressure (NIBP) measurement during general anaesthesia; a case report. [v1; ref status: indexed, http://f1000r.es/2oi
OpenAIRE
Smith, Matthew M. J.
2014-01-01
A patient undergoing general anaesthesia for neurosurgery exhibited an unexpected sudden decrease in the BiSpectral Index (BIS) value to near-zero. This prompted the detection of profound hypotension using non-invasive blood pressure (NIBP) measurement and expedited urgent assessment and treatment, with the patient making a full recovery. Widely regarded as a ‘depth of anaesthesia’ monitor, this case demonstrates the potential extra clinical benefit BIS may have in the detection of critical i...
1. BiSpectral Index (BIS monitoring may detect critical hypotension before automated non-invasive blood pressure (NIBP measurement during general anaesthesia; a case report. [v1; ref status: indexed, http://f1000r.es/2oi
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Matthew M. J. Smith
2014-01-01
Full Text Available A patient undergoing general anaesthesia for neurosurgery exhibited an unexpected sudden decrease in the BiSpectral Index (BIS value to near-zero. This prompted the detection of profound hypotension using non-invasive blood pressure (NIBP measurement and expedited urgent assessment and treatment, with the patient making a full recovery. Widely regarded as a ‘depth of anaesthesia’ monitor, this case demonstrates the potential extra clinical benefit BIS may have in the detection of critical incidents such as anaphylaxis during general anaesthesia.
2. Bispectral index-guided anaesthesia for off-pump coronary artery bypass grafting
OpenAIRE
Muralidhar Kanchi; Banakal Sanjay; Murthy Keshav; Garg Rajneesh; Rani G; Dinesh R
2008-01-01
Bispectral index (BIS) monitoring may assist reduction in utilisation of anaesthetic agents during general surgical procedures. This study was designed to test whether the use of BIS monitoring reduces the anaesthetic requirements during off-pump coronary artery bypass grafting (CABG). This prospective - clinical trial was conducted on 40 adult patients undergoing elective off-pump CABG. Patients received either isoflurane or propofol anaesthesia. BIS monitoring, which guided the dose of anae...
3. Nitrous Oxide and Nitrous Oxide-Free Low-Flow Anesthesia Using Bispectral Index Monitoring: Effects on Hemodynamics, Recovery Times, Volatile Anesthetic Consumption and Costs
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Bengü Gülhan Köksal
2010-12-01
Full Text Available Aim: In this study, we aimed to compare the effects of desfluraneN2O and desflurane-fentanyl combinations on hemodynamics, recovery times, volatile anesthetic consumption and costs in low-flow desflurane anesthesia by bispectral index (BIS monitoring of depth of anesthesia. Methods: After approval of ethics committee and obtaining patient consents, 60 patients were divided into two equal groups randomly. Non-invasive blood pressure measurement, ECG, SpO2 and BIS were monitored. All patients received 10 L .min-1 100% oxygen with mask for 5 minute before intubation. 2 mg.kg-1 propofol, 2 μg.kg-1 fentanyl and 0.6 mg.kg-1 rocuronium bromide were administered at induction in both groups. Desfluran 6% was chosen for anesthesia maintenance. Group 1 received 50% O2-N2O mixture in 6 L.min-1 and Group 2 received 50% O2-air mixture in 6 L.min-1 as carrier gas. Low-flow anesthesia (1 L.min-1 was started after a 10-min period of initial high flow (6 L.min-1. In Group 2, infusion of fentanyl was begun in 1 μg.kg.hour-1 rate. Desflurane level was adjusted at a main BIS value of 40-60. Blood pressure, heart rate, FiO2, etO2, FiN22, EtN2O, FiCO2, EtCO2, Fidesfluran and Etdesflurane were recorded. Results: There were no significant differences between the two groups in terms of heart rate, arterial blood pressure, settings of desfluran and recovery time. BIS values (p<0.001 and anesthetic agent costs (p<0.001 were higher in Group 2. Conclusion: Using fentanyl infusion instead of nitrous oxide in low flow-anesthesia with desflurane did not alter the hemodynamic parameters. Fentanyl infusion with medical air-oxygen as carrier gas is an alternative technique, but increases BIS values and anesthetic agent costs. (The Medical Bulletin of Haseki 2010; 48: 132-8
4. Usefulness of the bispectral index during cardiopulmonary resuscitation -A case report-
OpenAIRE
Jung, Jin Yong; Kim, Yeonbaek; Kim, Jung-Eun
2013-01-01
The usefulness of using the bispectral index (BIS) for monitoring during cardiopulmonary resuscitation (CPR) is not clearly understood. However, BIS has been a popular anesthetic monitoring device used during operations. The case presented is of a pregnant woman going into cardiac arrest due to an amniotic fluid embolism during a Cesarean section. CPR was performed, but neither the return of spontaneous circulation (ROSC) nor the return of consciousness was achieved, despite 50 min of effecti...
5. The effect of aging on bispectral index before and after sedation: a prospective study
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Mahoori A
2010-08-01
Full Text Available "nBackground: The Bispectral Index (BIS is an EEG-derived value that measures the sedative and hypnotic component of the anesthetic state. The effects of age on the bispectral index have not been well documented. The objective of the present study was to determine the influence of age on hypnotic requirement and bispectral index in awake and in patients with sedation induced by midazolam. "n"nMethods: Eighty patients were enrolled in this prospective observational study. The patients in study group were aged more than 70 years, and the age in control group ranged 20-40 years. Baseline recording of BIS was taken in awake patients in two groups for few minutes. Five minutes after administration of 0.02 mg/kg IV midazolam the BIS value also was taken and recorded. "n"nResults: In the study group, patients had a mean base BIS 94±3 compared with 97.3±1 in the control group (p< 0.0001. Five minutes after administration of 0.02 mg/kg midazolam the value were 80.9±6 and 90.4±3 respectively (p< 0.0001. "n"nConclusion: When BIS is used as a monitor of hypnosis in the elderly, we recommend that a baseline recording be taken before induction for a few minutes to alert the anesthesia provider to the possibility of low initial values. Further studies are needed to verify if the recommended range of 50-60 of BIS during clinical anesthesia is also adequate in the elderly with low initial baseline BIS or if this range needs adjusting in view of reduced initial BIS value.
6. Comparison of the EEG-based SNAP index and the Bispectral (BIS) index during sevoflurane-nitrous oxide anaesthesia.
Science.gov (United States)
Ruiz-Gimeno, P; Soro, M; Pérez-Solaz, A; Carrau, M; Belda, F J; Jover, J L; Aguilar, G
2005-12-01
The BIS monitor (Aspect Medical Inc, Newton, USA) was the first electroencephalogram (EEG)-based monitor of the hypnotic effect reflected by a dimensionless figure ranging from 100 (awake state) to 0 (flat line EEG). Its widespread use makes it the most-studied and the best-known among same intended devices. Its algorithm processes low-frequency EEG oscillations in order to provide the Bispectral index. A BIS index ranging from 40 to 60 has been established as the proper for surgical performance. The BIS monitor permits a closer approach to the hypnotic component of anaesthesia beyond clinical signs and may reduce the probability of intraoperative awareness; therefore, it has become a recommended monitoring tool in routine practice. The SNAP monitor (Nicolet Biomedical, Madison WI, USA) is also intended for monitoring the hypnotic effect of anaesthetics, which is in turn displayed as an index ranging from 100 to 0, with 100 meaning a fully awake state and 0 meaning no brain activity. The algorithm of the SNAP monitor is featured by its additional processing of ultra-high EEG frequencies, which seem to be involved in the formation of consciousness. The use of these frequencies would theoretically improve responsiveness during increased brain activity. We studied its behaviour patterns and capability to monitor the hypnotic effect induced by sevoflurane-nitrous oxide by comparison with the BIS index. Seventy patients ASA I-III were induced with propofol, fentanyl and rocuronium, and maintained with sevoflurane-N(2)O. BIS and SNAP indices were simultaneously recorded before induction, after intubation, after incision, at the following 10, 30 and 50 minutes, awakening and extubation time points, together with heart rate and blood pressure. The Pearson correlation was R(2) = 0.68 (p < .05). The Bland and Altman test showed a bias of 14.3 for SNAP index values with respect to BIS index values. We concluded that the SNAP index correlates with variations in the hypnotic
7. Bispectral index reveals death-feigning behavior in a red kite (Milvus milvus).
Science.gov (United States)
Martin-Jurado, Olga; Simova-Curd, Stefka; Bettschart-Wolfensberger, Regula; Hatt, Jean-Michel
2011-06-01
Red kites (Milvus milvus) are birds of prey known to feign death in the presence of humans. An adult wild red kite was anesthetized with isoflurane for coelioscopy. During surgery, heart rate and respiratory rate ranged from 240 to 260 beats per minute and from 16 to 28 breaths rates per minute, respectively. Pupil and corneal reflexes remained present, and body temperature was maintained at 40.4 degrees C (104.7 degrees F). Suppression ratio was 0 during the anesthetic episode. The bispectral index was 44 immediately after intubation, ranged from 44 to 57 during maintenance of anesthesia, and was 59 at the moment of extubation. The index increased to 85 while the kite remained immobile, which was suggestive of feigning death in sternal recumbency. Once the bird was perched upright, it immediately kept the upright position, which confirmed the correspondence of the bispectral index value (85) with a fully conscious patient. Although behavioral or cardiorespiratory variables remained unchanged, the degree of hypnosis was indicated by the bispectral index, which anticipated a possible sudden awakening episode of this bird. PMID:21877451
8. Evaluation of the Adequacy of General Anesthesia in Cesarean Section by Bispectral Index
OpenAIRE
2013-01-01
Background: Awareness and recall, though not common, are the major hazards of general anesthesia, especially in Cesarean section (C/S) because of the absence of benzodiazepine and opioids for a significant time during anesthesia. In this study, the Bispectral Index (BIS), end-tidal isoflurane, and hemodynamic parameters were examined to evaluate the depth of the routine general anesthetic technique in C/S. Methods: This study was carried out on 60 parturient patients undergoing elective C/...
9. Effects of cardiopulmonary bypass on propofol pharmacokinetics and bispectral index during coronary surgery
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Ricardo Antonio G. Barbosa
2009-03-01
Full Text Available PURPOSE: Cardiopulmonary bypass is known to alter propofol pharmacokinetics in patients undergoing cardiac surgery. However, few studies have evaluated the impact of these alterations on postoperative pharmacodynamics. This study was designed to test the hypothesis that changes in propofol pharmacokinetics increase hypnotic effects after cardiopulmonary bypass. METHODS: Twenty patients scheduled for on-pump coronary artery bypass graft (group, n=10 or off-pump coronary artery bypass graft (group, n=10 coronary artery bypass grafts were anesthetized with sufentanil and a propofol target controlled infusion (2.0 µg/mL. Depth of hypnosis was monitored using the bispectral index. Blood samples were collected from the induction of anesthesia up to 12 hours after the end of propofol infusion, at predetermined intervals. Plasma propofol concentrations were measured using high-performance liquid chromatography, followed by a non-compartmental propofol pharmacokinetic analysis. Data were analyzed using ANOVA, considering p<0.05 as significant. RESULTS: After cardiopulmonary bypass, despite similar plasma propofol concentrations in both groups, bispectral index values were lower in the on-pump coronary artery bypass graft group. Time to extubation after the end of propofol infusion was greater in the on-pump coronary artery bypass graft group (334 ± 117 vs. 216 ± 85 min, p = 0.04. Patients undergoing cardiopulmonary bypass had shorter biological (1.82 ± 0.5 vs. 3.67 ± 1.15h, p < 0.01 and terminal elimination (6.27 ± 1.29 vs. 10.5h ± 2.18, p < 0.01 half-life values, as well as higher total plasma clearance (28.36 ± 11.40 vs.18.29 ± 7.67 mL/kg/min, p = 0.03, compared to patients in the off-pump coronary artery bypass graft group. CONCLUSION: Aside from the increased sensitivity of the brain to anesthetics after cardiopulmonary bypass, changes in propofol pharmacokinetics may contribute to its central nervous system effects.
10. Bispectral index-guided anaesthesia for off-pump coronary artery bypass grafting
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Muralidhar Kanchi
2008-01-01
Full Text Available Bispectral index (BIS monitoring may assist reduction in utilisation of anaesthetic agents during general surgical procedures. This study was designed to test whether the use of BIS monitoring reduces the anaesthetic requirements during off-pump coronary artery bypass grafting (CABG. This prospective - clinical trial was conducted on 40 adult patients undergoing elective off-pump CABG. Patients received either isoflurane or propofol anaesthesia. BIS monitoring, which guided the dose of anaesthetic, was carried out in 50 percent of the patients. The amount of anaesthetic agent (isoflurane or propofol administered from the start of anaesthesia to the end of surgical procedure was calculated and were compared in four groups of patients - namely Group A (I-no BIS received isoflurane; end tidal concentration was maintained at 1-1.2% in a low flow technique throughout the procedure, Group B (I-BIS received isoflurane in a low flow technique; inspired concentration was dictated by BIS value maintained at 50; Group C (P-no BIS received propofol at a dose range of 4-8 mg/kg/hr and in Group D(P-BIS the propofol infusion rate was dictated by BIS value maintained at 50. The quantity of isoflurane was significantly less for Group B (I-BIS as compared with Group A (I-no BIS (37 ± 4 vs. 24 ± 4 ml; p< 0.05 and similarly the amount of propofol infused was significantly less in Group D (P-BIS as compared with Group C (P-no BIS (176 ± 9 vs. 120 ± 6 ml; p< 0.05. BIS guided anaesthesia reduces the anaesthetic agent required for the performance of off-pump CABG. This can be extrapolated in terms of saving agent and reduced cardiac depression during off-pump CABG.
11. Evaluation of the Adequacy of General Anesthesia in Cesarean Section by Bispectral Index
Directory of Open Access Journals (Sweden)
2013-09-01
Full Text Available Background: Awareness and recall, though not common, are the major hazards of general anesthesia, especially in Cesarean section (C/S because of the absence of benzodiazepine and opioids for a significant time during anesthesia. In this study, the Bispectral Index (BIS, end-tidal isoflurane, and hemodynamic parameters were examined to evaluate the depth of the routine general anesthetic technique in C/S. Methods: This study was carried out on 60 parturient patients undergoing elective C/S. A standardized anesthetic technique was applied: induction with Thiopental (4-5 mg/kg and Succinylcholine (1.5-2 mg/kg as well as maintenance with O2, N2O, and isoflurane. Electrocardiogram, heart rate, blood pressure, Spo2, end-tidal isoflurane concentration, BIS, and any clinical signs of inadequate depth of anesthesia such as movement, sweating, lacrimation, coughing, and jerking were continuously monitored and recorded at 16 fixed time points during anesthesia. Results: A median BIS of less than 70 (range: 42-68 was obtained on all occasions during surgery; however, at each milestone, at least 20% of the patients had BIS values above 60. Hemodynamic parameters increased significantly in some patients, especially during laryngoscopy and intubation. No patient experienced recall or awareness. Conclusion: The currently used general anesthetic technique in our center appears inadequate in some milestones to reliably produce BIS values less than 60, which are associated with lower risk of awareness. Therefore, with respect to such desirable outcomes as good Apgar and clinical status in neonates, we would recommend the application of this method (if confirmed by further studies through larger dosages of anesthetic agents.
12. Comparison of the ability of wavelet index and bispectral index for reflecting regain of consciousness in patients undergone surgery
Institute of Scientific and Technical Information of China (English)
ZHANG Xiao-tong; CHENG Hao; XIONG Wei; WANG Bao-guo
2010-01-01
Background Wavelet index (WLI) is a new parameter for monitoring depth of anesthesia based on Wavelet analysis.We observed the change of WLI and bispectral index (BIS) in patients regain of consciousness (ROC) in the absence of frontalis electromyographic (EMG) interference. The aim of this study was to compare the ability of WLI and BIS for reflecting ROC in patients undergone surgery.Methods Twelve patients who were scheduled for maxillofacial surgeries were enrolled in the study. BIS and WLI values were monitored continually. After being given midazolam and remifentanil, patients were asked to squeeze the investigator's hand ever 30 seconds. Patients were continuously given propofol until loss of consciousness (LOC1).Tunstall's isolated forearm technique was used to test the surgical consciousness in patients. After total muscle relaxation,endotracheal intubations were performed, and the patients were connected to a ventilator. Then, propofol was withdrawn until the patients showed regain of consciousness (ROC1) and an awareness reaction. After the command test, patients were readministered with propofol until loss of consciousness (LOC2). After surgery, all of the sedatives were withdrawn,and the patients were let to regain consciousness (ROC2).Results The BIS values of twelve patients at ROC1 after using muscle relaxant were much lower than those at LOC1 and ROC2 without using muscle relaxant, showing statistical significance (P <0.05). Meanwhile, the WLI values of twelve patients at ROC1 after using muscle relaxant were much higher than those at LOC1 and equal to ROC2 without using muscle relaxant, showing statistical significances (P <0.05) between ROC1 and LOC1.Conclusions This study showed that under muscle relaxation or facial paralysis, when there is no EMG signal, BIS can not accurately reflect regain of consciousness in surgical patients, but WLI can reflect it accurately. So WLI may have advantages for reflecting state of consciousness in surgical
13. Quando o índice bispectral (BIS pode fornecer valores espúrios Cuando el índice bispectral (BIS puede suministrar valores falsos When the bispectral index (Bis can give false results
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Leonardo Teixeira Domingues Duarte
2009-02-01
profundidad de la anestesia, reduce el aparecimiento del despertar y memoria intraoperatoria. Esa revisión tuvo el objetivo de presentar situaciones clínicas en que el BIS denota valores no verdaderos, que están falsamente elevados o reducidos, debido a condiciones del paciente o a acciones de anestésicos no previstos cuando se elaboró su algoritmo. CONTENIDO: Los valores del BIS pueden sufrir la alteración y el influjo en múltiples situaciones clínicas en que existen estándares anormales del EEG; efecto de diferentes anestésicos y otros fármacos no incluidos en la elaboración de su algoritmo; interferencia por equipos eléctricos; o debido a peculiaridades del monitor. CONCLUSIÓN: A pesar de que el algoritmo del BIS haya sufrido diversas alteraciones desde su primera versión, esas situaciones que determinan variaciones falsas de los valores del BIS, deben ser reconocidas por el anestesiólogo para evitar complicaciones, sean a causa de la sobredosis anestésica, o por subdosis que podrán causar el despertar y la memoria intraoperatoria.BACKGROUND AND OBJECTIVES: The bispectral index (BIS is a multifactorial parameter derived from the electroencephalogram (EEG, which allows monitoring of the hypnotic component of anesthesia. It was obtained from the algorithm based on the analysis of a large number of EEGs from volunteers and patients undergoing sedation and general anesthesia with different anesthetic agents. The use of BIS to monitor the depth of anesthesia reduces the incidence of intraoperative awakening and recall, among other benefits. The objective of this review was to present clinical situations in which the BIS gives false results, either elevated or decreased, due to conditions related to the patient or anesthetic actions unforeseen when the algorithm was elaborated. CONTENTS: The bispectral index can be altered and influenced in different clinical situations in which abnormal EEG patterns are present; the effects of different anesthetics and other
14. BIS在氯胺酮联合咪达唑仑小儿麻醉深度中的监测价值评价%Evaluation on monitoring value of bispectral index in pediatric anesthesia depth of ketamine combined with midazolam
Institute of Scientific and Technical Information of China (English)
蔡军; 武玉清; 周成华; 周策; 陆富钊; 李鑫; 黄鹂; 李伟; 张永; 陈虎
2012-01-01
Objective To evaluate the value of bispectral index (BIS) monitor in pedo-oblique inguinal hernia operation through anesthesia by ketamine combined with midazolam . Methods Forty 2-to 6-year-old child patients undergoing pedo-oblique inguinal hernia surgery in 2011 were randomly divided into 2 groups; BIS group (B, n=20) and control group (C, n=20). In group B , we controlled the dosage of ketamine and midazolam by BIS monitor (78±5). In group C, we controlled the dosage of ketamine and midazolam by observation of haemodynamic reaction , respiratory rate and boby movement. Results Compared to group C , there is less haemodynamic fluctuation and shorter analepsia time and better sedation in group B. Conclusion BIS monitor could control the depth of anesthesia , shorten analepsia time by continuous and objective monitoring in pedo-oblique inguinal hernia operation , which results in better sedation in surgery and enhancementof pedo-patient comfort and safety.%目的 探讨脑电双频指数(bispectral index,BIS)在氯胺酮联合咪达唑仑进行小儿腹股沟斜疝手术麻醉深度监测中的应用价值.方法 选择择期行腹股沟斜疝手术的患儿40例,年龄2~6岁,ASAⅠ~Ⅱ级,随机分成 BIS监测组(B组)和对照组(C组).B组 (20例) 通过术中监测BIS数值,调整氯胺酮和咪达唑仑剂量使其维持在78±5;C组根据术中患儿的血流动力学反应、呼吸频率改变和出现体动反应来调整氯胺酮和咪达唑仑用量大小.结果 同C组相比,B组患儿镇静充分,血流动力学波动较小,术后苏醒时间缩短,有统计学意义(P<0.05).结论 应用BIS能连续、客观地监测并控制氯胺酮联合咪达唑仑进行小儿腹股沟斜疝手术的麻醉深度,缩短术后苏醒时间,有利于术中镇静及增强患儿的舒适感和安全性.
15. Bispectral index correlates with regional cerebral blood flow during sleep in distinct cortical and subcortical structures in humans.
Science.gov (United States)
Noirhomme, Q; Boly, M; Bonhomme, V; Boveroux, P; Phillips, C; Peigneux, P; Soddu, A; Luxen, A; Moonen, G; Maquet, P; Laureys, S
2009-03-01
The relationship between the Bispectral Index (BIS), an EEG-based monitor of anesthesia, and brain activity is still unclear. This study aimed at investigating the relationship between changes in BIS values during natural sleep and regional cerebral blood flow (rCBF) variations, as measured by Positron Emission Tomography (PET). Data were obtained from six young, healthy, right-handed, male volunteers (20-30 years old) using the H2(15)O infusion method. PET scans were performed both during waking and various stages of sleep. BIS values were monitored continuously and recorded during each PET scan. Positive correlations were detected between BIS and rCBF values in dorsolateral prefontal, parietal, anterior and posterior cingulate, precuneal, mesiofrontal, mesiotemporal and insular cortices. These areas belong to a frontoparietal network known to be related to awareness of self conscious sensory perception, attention and memory. BIS values also positively correlated with activity in brainstem and thalami, both structures known to be involved in arousal and wakefulness. These results show that BIS changes associated with physiological sleep depth co-vary with the activity of specific cortical and subcortical areas. The latter are known to modulate arousal, which in turn allows sustained thalamo-cortical enhancement of activity in a specific frontoparietal network known to be related to the content of consciousness. Thus, although mainly derived from frontal EEG, BIS could represent a wider index of cerebral activity. PMID:19678596
16. Clinical vs. bispectral index-guided propofol induction of anesthesia: A comparative study
Directory of Open Access Journals (Sweden)
Snehdeep Arya
2013-01-01
Full Text Available Background: Clinically optimized focusing of drug administration to specific need of patient with bispectral index (BIS monitoring results in reduced dose and faster recovery of consciousness. This study was planned with an aim to study and compare the conventional clinical end point or BIS on the requirement of dosage of propofol, hemodynamic effects, and BIS alterations following propofol induction. Methods: 70 patients, ASA I and II, 20-60 years undergoing elective surgical procedure under general anesthesia with endotracheal intubation were selected and divided into two groups. Group A received (inj. fentanyl (2 μg/kg, followed 3 min later by inj. propofol at the rate of 30 mg/kg/hr infusion till the loss of response to verbal command while group B received inj. fentanyl (2 μg/kg, followed 3 min later by inj. propofol at the rate of 30 mg/kg/hr infusion. The end point of hypnosis was when the BIS value was sustained for 1 min at 48±2. The patients were intubated. Total induction dose of propofol was noted in each group. The value of BIS and hemodynamic parameters (heart rate, systolic/diastolic blood pressure were noted at the time of loss of consciousness, at the time of intubation, and 1 min after intubation, thereafter every minute for first 10 min and thereafter every 10 min till end of surgery. Any involuntary muscle activity such as jerky movements, dystonic posturing, and opisthotonos were also recorded. Results: The mean dose of propofol used in groups A and B were 1.85±0.48 mg/kg and 1.79±0.41 mg/kg, respectively. The dosage used in group B were less but not clinically significant (P=0.575. On comparing the dosage of propofol in males among the groups there was a significantly lower dosage of propofol required in group B (2.06±0.45 mg/kg and 1.83±0.32 mg/kg, respectively, P=0.016. This decrease however was not seen in female patients dosage being 1.65±0.44 mg/kg and 1.75±0.49 mg/kg, respectively (P=0.372. The hemodynamic
17. The effect of music on preoperative sedation and the bispectral index.
Science.gov (United States)
Ganidagli, Suleyman; Cengiz, Mustafa; Yanik, Medaim; Becerik, Cevdet; Unal, Bahriye
2005-07-01
We assessed the effect of music on the level of sedation and the electroencephalograph bispectral index (BIS) during the preoperative period. Fifty-four ASA physical status I-II patients, scheduled for elective septo-rhinoplastic surgery, were included in the study. Subjects were assigned to receive either music (music group; n = 28) or no music (control group; n = 26) during the preoperative period. Sedative premedication was provided with midazolam 0.08 mg/kg IM. Observer's Assessment of Alertness/Sedation Scales (OAAS) scores and BIS values were recorded at specific time intervals. In the control group, there were more patients with an OAAS score of 1 than in the music group at 30 min after midazolam injection. In addition, there were more patients with an OAAS score of 2 in the control group than in the music group at 30-50 min. However, there were significantly more patients with an OAAS score of 3 in the music group than in the control group at 20-50 min. BIS values of the music group were also smaller than the control group at 30 and 40 min. BIS values were significantly decreased from baseline values at 10-50 min in the music group, whereas BIS values decreased at 30-50 min in the control group. In conclusion, listening to music during midazolam premedication is associated with an increase in sedation level in the preoperative period as reflected by a lower BIS value. PMID:15976214
18. Feasibility of bispectral index-guided propofol infusion for flexible bronchoscopy sedation: a randomized controlled trial.
Directory of Open Access Journals (Sweden)
Yu-Lun Lo
Full Text Available OBJECTIVES: There are safety issues associated with propofol use for flexible bronchoscopy (FB. The bispectral index (BIS correlates well with the level of consciousness. The aim of this study was to show that BIS-guided propofol infusion is safe and may provide better sedation, benefiting the patients and bronchoscopists. METHODS: After administering alfentanil bolus, 500 patients were randomized to either propofol infusion titrated to a BIS level of 65-75 (study group or incremental midazolam bolus based on clinical judgment to achieve moderate sedation. The primary endpoint was safety, while the secondary endpoints were recovery time, patient tolerance, and cooperation. RESULTS: The proportion of patients with hypoxemia or hypotensive events were not different in the 2 groups (study vs. control groups: 39.9% vs. 35.7%, p = 0.340; 7.4% vs. 4.4%, p = 0.159, respectively. The mean lowest blood pressure was lower in the study group. Logistic regression revealed male gender, higher American Society of Anesthesiologists physical status, and electrocautery were associated with hypoxemia, whereas lower propofol dose for induction was associated with hypotension in the study group. The study group had better global tolerance (p<0.001, less procedural interference by movement or cough (13.6% vs. 36.1%, p<0.001; 30.0% vs. 44.2%, p = 0.001, respectively, and shorter time to orientation and ambulation (11.7±10.2 min vs. 29.7±26.8 min, p<0.001; 30.0±18.2 min vs. 55.7±40.6 min, p<0.001, respectively compared to the control group. CONCLUSIONS: BIS-guided propofol infusion combined with alfentanil for FB sedation provides excellent patient tolerance, with fast recovery and less procedure interference. TRIAL REGISTRATION: ClinicalTrials. gov NCT00789815.
19. Effect of a single dose of esmolol on the bispectral index to endotracheal intubation during desflurane anesthesia
OpenAIRE
Choi, Eun Mi; Min, Kyeong Tae; Lee, Jeong Rim; Lee, Tai Kyung; Choi, Seung Ho
2013-01-01
Background In this prospective, randomized, double-blind, placebo-controlled trial, we investigated the effect of a single dose of esmolol on the bispectral index (BIS) to endotracheal intubation during desflurane anesthesia. Methods After induction of anesthesia, 60 patients were mask-ventilated with desflurane (end-tidal 1 minimum alveolar concentration) for 5 min and then received either normal saline, esmolol 0.5 or 1 mg/kg, 1 min prior to intubation (control, esmolol-0.5 and esmolol-1 gr...
20. Entropy and bispectral index for assessment of sedation, analgesia and the effects of unpleasant stimuli in critically ill patients: an observational study
Science.gov (United States)
Haenggi, Matthias; Ypparila-Wolters, Heidi; Bieri, Christine; Steiner, Carola; Takala, Jukka; Korhonen, Ilkka; Jakob, Stephan M
2008-01-01
Introduction Sedative and analgesic drugs are frequently used in critically ill patients. Their overuse may prolong mechanical ventilation and length of stay in the intensive care unit. Guidelines recommend use of sedation protocols that include sedation scores and trials of sedation cessation to minimize drug use. We evaluated processed electroencephalography (response and state entropy and bispectral index) as an adjunct to monitoring effects of commonly used sedative and analgesic drugs and intratracheal suctioning. Methods Electrodes for monitoring bispectral index and entropy were placed on the foreheads of 44 critically ill patients requiring mechanical ventilation and who previously had no brain dysfunction. Sedation was targeted individually using the Ramsay Sedation Scale, recorded every 2 hours or more frequently. Use of and indications for sedative and analgesic drugs and intratracheal suctioning were recorded manually and using a camera. At the end of the study, processed electroencephalographical and haemodynamic variables collected before and after each drug application and tracheal suctioning were analyzed. Ramsay score was used for comparison with processed electroencephalography when assessed within 15 minutes of an intervention. Results The indications for boli of sedative drugs exhibited statistically significant, albeit clinically irrelevant, differences in terms of their association with processed electroencephalographical parameters. Electroencephalographical variables decreased significantly after bolus, but a specific pattern in electroencephalographical variables before drug administration was not identified. The same was true for opiate administration. At both 30 minutes and 2 minutes before intratracheal suctioning, there was no difference in electroencephalographical or clinical signs in patients who had or had not received drugs 10 minutes before suctioning. Among patients who received drugs, electroencephalographical parameters
1. 意识指数监测小儿吸入七氟醚麻醉深度的准确性:与BIS的比较%Accuracy of index of consciousness in monitoring depth of anesthesia with sevoflurane inhalation in children: a comparison with bispectral index
Institute of Scientific and Technical Information of China (English)
李茜; 张丽
2013-01-01
Objective To evaluate the accuracy of the index of consciousness (IoC) in monitoring the depth of anesthesia with sevoflurane inhalation in children,by comparing it with the bispectral index (BIS).Methods Forty-two ASA physical status Ⅰ or Ⅱ children,aged 8-12 yr,scheduled for elective abdominal surgery under general anesthesia,were studied.Anesthesia was induced with sevoflurane inhalation.The patients were endotracheally intubated.The concentration of sevoflurane was then adjusted to maintain the end-tidal concentration of sevoflurane (CETSev) at 1.6％,2.1％,2.6％,3.1％,3.6％,4.1％ and 4.6％ for5 min.The IoC and BIS values were recorded simultaneously.Results When CETSev ＜ 3.1％,CETSev was negatively correlated with IoC and BIS values,and the correlation coefficients between CETSev and IoC and BIS values were-0.927 (r1) and -0.869 (r2),respectively (P ＜ 0.01).When 3.1％ ≤ CETSev ≤ 4.6 ％,CET Sev was negatively correlated with IoC and BIS values,and the correlation coefficients between CETSev and IoC and BIS values were-0.808 (r3,P＜ 0.01) and-0.430 (r4,P ＜ 0.05),respectively.Comparison of the absolute value of correlation coefficients:there was no significant difference between r1,r2 and r3 (P ＞ 0.05) ; r1,r2 and r3 were significantly larger than r4 (P ＜ 0.01).Conclusion IoC can accurately reflect the depth of anesthesia with sevoflurane inhalation in children and when 3.1％ ≤ CET Sev ≤ 4.6 ％,the accuracy of IoC in monitoring the depth of anesthesia is superior to that of BIS.%目的 评价意识指数(IoC)监测小儿吸入七氟醚麻醉深度的准确性.方法 择期全麻下行腹部手术患儿42例,ASA分级Ⅰ级或Ⅱ级,性别不限,年龄8～ 12岁.吸入七氟醚麻醉诱导气管插管后,调节吸入七氟醚的浓度,分别维持呼气末七氟醚浓度(CET Sev) 1.6％、2.1％、2.6％、3.1％、3.6％、4.1％和4.6％5 min,同步记录IoC值和BIS值.结果 CET Sev＜ 3.1％时,其与IoC值、BIS值均呈负
2. Effects of Phenytoin Therapy on Bispectral Index and Haemodynamic Changes Following Induction and Tracheal Intubation
Directory of Open Access Journals (Sweden)
Parmod P Bithal
2009-01-01
Full Text Available Laryngoscopy and tracheal intubation (LTI increase blood pressure and heart rate (HR. Intensity of these changes is influenced by the anaesthetic depth assessed by the bispectral index (BIS. We determined the effect of phenytoin on anaesthetic depth and its influence on haemodynamics following LTI. Fifty patients of ASA grades I and II on oral phenytoin 200 to 300mg per day for more than one week were compared with 48 control patients. Standard anaesthesia technique was followed. BIS, non invasive mean blood pressure (MBP and HR were recorded 30, 60, 90 and 120 sec after LTI. Phenytoin group needed lesser thiopentone for induction, 5 mg (1.1 vs. 4.3 mg (0.7 [p=0.036]. BIS was significantly lower in the phenytoin group vs. the control 30, 60, 90 and 120 sec after LTI [43.1 (16.0 vs. 48.9 (14.9, p=0.068, 56.3 (16.7 vs. 64.3 (14.4, p=0.013, 59.8 (15.8 vs. 67.5 (12.1, p=0.008, 62.6 (14 vs. 68.9 (11.2, p=0.017, and 64.2 (11.3 vs. 69 (11.7, p=0.033], respectively. MBP was also lower in the phenytoin group 30, 60, 90 and 120 sec after LTI [112.8 mmHg (13.8, vs. 117.9 mmHg (18 p=0.013, 108.6 (12.8 vs. 117.5 (16 p=0.003, 106.1 mmHg (14.1 vs. 113.2 mmHg (14.9, p=0.017, 101.8 mmHg (13.8 vs. 109.5 mmHg (14.1, p=0.007], respectively. HR was lower in phenytoin group at 30 sec. (p=0.027, 60 sec (p=0.219, and again at 120 sec (p=0.022. Oral phenytoin therapy for over a week results in greater anaesthetic depth as observed using BIS, which also attenuated haemodynamic response of LTI.
3. Observation of anesthesia depth in severe burn patients with target controlled infusion of propofol and remifentanil by bispectral index
Directory of Open Access Journals (Sweden)
Zheng-gang GUO
2012-04-01
Full Text Available Objective To evaluate the feasibility and efficiency of bispectral index (BIS for monitoring the anesthesia depth of severe burn patients with target controlled infusion (TCI of propofol and remifentanil. Methods A total of 80 severe burns patients undergoing eschar excision ( < 1week were randomly divided into BIS group (group A and control group (group B, with 40 cases assigned in each group. These patients were 18 years to 65 years old, ASAⅡ-Ⅲ. Their total burn surface areas (TBSA were from 31% to 50%, or 11% to 20% with three-degree burns. All patients received remifentanil and propofol for TCI intravenous anesthesia. The mean arterial pressure (MAP and heart rate (HR were determined at following time points, namely, entrance to the operation room, loss of consciousness, 2min after intubation, before surgery, 2, 15, and 30min after the start of surgery, end of surgery, eye opening, and period when Aldrete score reaching 9 points, as well as the target concentrations of remifentanil and propofol. The time frames from stoppage of drug infusion to eye opening and the period when Aldrete score reaching 9 points were also recorded. Results Compared with group B, the target concentrations of remifentanil (2.12±0.35ng/ml vs. 2.50±0.21ng/ml and propofol (2.54±0.22μg/ml vs. 2.86±0.31μg/ml were significantly lower in group A during anesthetic maintenance (P < 0.01. The time interval from stoppage of drug infusion to eye opening (7.90±0.58min vs. 8.35±0.66min and period when Aldrete score reaching 9 points (9.15±0.69min vs. 11.13±0.96min were significantly reduced in group A. The MAP of both groups from loss of consciousness at all time points, except 2min after intubation, was significantly lower than the basic values upon entrance into the operation room (P < 0.05. The HR at all time points were significantly lower compared with the basic data (P < 0.05. Conclusion BIS for monitoring the anesthetic depth of severe burns patients
4. Closed-loop control of anesthesia using bispectral index - Performance assessment in patients undergoing major orthopedic surgey under combined general and regional anesthesia
NARCIS (Netherlands)
Absalom, AR; Sutcliffe, N; Kenny, GN
2002-01-01
Background: The Bispectral Index (BIS) is an electroencephalogram-derived measure of anesthetic depth. A closed-loop anesthesia system was built using BIS as the control variable, a proportional-integral-differential control algorithm, and a propofol target-controlled infusion system as (lie control
5. The accuracy and clinical feasibility of a new Bayesian-based closed-loop control system for propofol administration using the bispectral index as a controlled variable
NARCIS (Netherlands)
De Smet, Tom; Struys, Michel M. R. F.; Neckebroek, Martine M.; Van den Hauwe, Kristof; Bonte, Sjoert; Mortier, Eric P.
2008-01-01
BACKGROUND: Closed-loop control of the hypnotic component of anesthesia has been proposed in an attempt to optimize drug delivery. Here, we introduce a newly developed Bayesian-based, patient-individualized, model-based, adaptive control method for bispectral index (BIS) guided propofol infusion int
6. Changes to the bispectral index and regional cerebral blood flow in a sedative state, caused by midazolam administration
International Nuclear Information System (INIS)
Psychosedation, as used in the field of dentistry, is intended to provide trouble-free dental care while maintaining a proper level of sedation. One drug used in psychosedation is midazolam, which is known to have a strong amnestic effect. In the current research, I sought to clarify whether the bispectral index (BIS) using electroencephalogram (EEG) analysis can be used for assessment of optimal sedation in psychosedation, and what effects midazolam has on the cerebrum's mechanism of memory. The subjects were 17 healthy adult volunteers. Intravenous sedation involved a single administration of 0.06 mg/kg midazolam, or 6 mg/kg/h propofol, administered for 5 minutes and then continuously administered for 25 minutes at 3 mg/kg/h. For nitrous oxide inhalation sedation, 10-30% nitrous oxide was used. Clinical sedation and the BIS were measured in a variety of circumstances. To examine the effects of midazolam on the central nervous system, changes in brain oxygen consumption in visual memory tasks were assessed through observing changes in areas of brain activation using 3T fMRI. With intravenous sedation using midazolam or propofol, the BIS decreased immediately after drug administration, and the BIS at which optimal sedation was clinically determined was about 65. In contrast, no decrease in the BIS was noted with nitrous oxide inhalation sedation. In observing areas of brain activation by fMRI, the oxygen consumption mainly of visual cortices in the occipital lobe increased as a result of stimulation by visual memory tasks. Regardless of the amnestic effect midazolam produced in subjects, it did not suppress activation of the visual cortices in the occipital lobe. In intravenous sedation using midazolam or propofol, the BIS is effective in determining optimal sedation, and appropriate perioperative management can be performed using the BIS. However, in nitrous oxide inhalation sedation it appears that the BIS cannot be used to monitor levels of sedation. Amnestic
7. Bispectral index in dogs with high intracranial pressure, anesthetized with propofol and submitted to two levels of FiO2
Directory of Open Access Journals (Sweden)
P.C.F. Lopes
2011-12-01
Full Text Available The effects of inspired oxygen fractions (FiO2 of 1 and 0.6 on bispectral index (BIS in dogs with high intracranial pressure, submitted to a continuous rate infusion of propofol were evaluated. Eight dogs were anesthetized on two occasions, receiving, during controlled ventilation, an FiO2 = 1 (G100 or an FiO2 = 0.6 (G60. Propofol was used for induction (10mg.kg-1, IV, followed by a continuous rate infusion (0.6mg.kg-1.minute-1. After 20 minutes, a fiber-optic catheter was implanted on the surface of the right cerebral cortex to monitor the intracranial pressure, the baseline measurements of BIS values, signal quality index, suppression ratio number, electromyogram indicator, end-tidal carbon dioxide partial pressure, mean arterial pressure, intracranial pressure and cerebral perfusion pressure were taken. Then, the blood flow from the right jugular vein was interrupted in order to increase intracranial pressure and after 20 minutes additional recordings were performed at 15-minute intervals (T0, T15, T30, T45 and T60. The arterial oxygen partial pressure varied according to the changes in oxygen. For the other parameters, no significant differences were recorded. The BIS monitoring was not influenced by different FiO2.
8. Comparison of equi-minimum alveolar concentration of sevoflurane and isoflurane on bispectral index values during both wash in and wash out phases: A prospective randomised study
OpenAIRE
Madhu Gupta; Iti Shri; Prashant Sakia; Deepika Govil
2015-01-01
Background and Aims: At equal minimum alveolar concentration (MAC), volatile agents may produce different bispectral index (BIS) values especially at low BIS levels when the effect is volatile agent specific. The present study was performed to compare the BIS values produced by sevoflurane and isoflurane at equal MAC and thereby assessing which is a better hypnotic agent. Methods: Sixty American Society of Anaesthesiologists I and II patients undergoing elective mastoidectomy were divided int...
9. The effect of different doses of esmolol on hemodynamic, bispectral index and movement response during orotracheal intubation: prospective, randomized, double-blind study
OpenAIRE
Mensure Yılmaz Çakırgöz; Aydın Taşdöğen; Çimen Olguner; Hülya Korkmaz; Ertuğrul Öğün; Burak Küçükebe; Esra Duran
2014-01-01
Objective: A prospective, randomized and double-blind study was planned to identify the optimum dose of esmolol infusion to suppress the increase in bispectral index values and the movement and hemodynamic responses to tracheal intubation. Materials and methods: One hundred and twenty patients were randomly allocated to one of three groups in a double-blind fashion. 2.5 mg kg-1 propofol was administered for anesthesia induction. After loss of consciousness, and before administration of 0.6 ...
10. Quando o índice bispectral (BIS) pode fornecer valores espúrios Cuando el índice bispectral (BIS) puede suministrar valores falsos When the bispectral index (Bis) can give false results
OpenAIRE
Leonardo Teixeira Domingues Duarte; Renato Ângelo Saraiva
2009-01-01
JUSTIFICATIVA E OBJETIVOS: O índice bispectral (BIS) é um parâmetro multifatorial derivado do eletroencefalograma (EEG) que permite a monitorização do componente hipnótico da anestesia. Foi obtido a partir de algoritmo derivado da análise de grande número de EEGs de voluntários e pacientes submetidos a sedações e anestesia geral com diferentes agentes anestésicos. Além de outros benefícios, o uso do BIS para monitorização da profundidade da anestesia reduz a ocorrência de despertar e memória ...
11. The use of Bispectral Index (BIS values as an indicator for sleep staging
Directory of Open Access Journals (Sweden)
Evangelia Nena
2009-01-01
Full Text Available SUMMARY. The aim of this study was to examine whether BIS values during sleep correspond to the different sleep stages, in order to assess BIS as an alternative means of sleep staging. Patients-Methods: The study was conducted on 23 patients who were examined concurrently with polysomnography (PSG for diagnosing sleep-disordered breathing and with BIS. Exclusion criteria were sleep duration <4 hours, sleep efficiency <80% on PSG and signal quality index (SQI <50% on BIS. Comparisons in recordings were performed. Results: The patients provided 806 different sleep periods. The mean BIS value was 93.6±4.8 in the wakeful state, and in sleep, according to each stage: 84±11.5 in stage 1, 75.4±13.2 in stage 2, 53.4±15.8 in slow wave sleep (SWS, and 81.5±13.3 during REM sleep. A significant difference was observed between BIS values in the wakeful state and stage 1 (p<0.005 and between stages 1 and 2 and SWS (p<0.001, but not between stage 1 and REM (p=0.102. Conclusion: BIS values decrease with sleep and remain low, with the exception of REM sleep, the BIS values in which overlap with those in stage 1, reducing the sensitivity of BIS in sleep staging. Pneumon 2009, 22(3:230-239.
12. Textile Index Monitor
Institute of Scientific and Technical Information of China (English)
2010-01-01
Textile Index Monitor is a new column that delivers a textile-specific price index profile in weeks that are bygone when this monthly magazine comes to your hand. China Textile City is the name of the world-largest yarn&fabric marketplace in the famous town of Keqiao in Zhejiang,China.Several years ago,Ministry of Commerce(MOC)set up a national price index centre for textiles-specific category,China Textile City takes the leading role in publishing its analytical report of textile price index on weekly,monthly,quarterly and yearly basis,making it possible for Keqiao or its textile city to be the weathercock for textiles market trend in China and in the world as well.From this issue,a new column is given to cover the gist&feeds of the latest developments&gradients in this market barometer.
13. Comparative study among acepromazine, chlorpromazine and methotrimeprazine in different doses, through bispectral index, term and pressure algimetry, in dogs / Estudo comparativo entre a acepromazina, clorpromazina e levomepromazina em diferentes doses, através do exame bispectral, termo e pressoalgimetria, em cães
Directory of Open Access Journals (Sweden)
Lidia Mitsuko Matsubara
2009-12-01
Full Text Available The study’s objective was to realize comparisons among different acepromazine, chlorpromazine and methotrimeprazine doses, evaluate parametric changes, test analgesia using press and term algimetry, and evaluate bispectral condition. 90 mongrel dogs were used, male and female, adult, weighting 10 to 15 Kg as a rule, distributed in 9 groups with 10 animals each. At first, second and third groups acepromazine was used at 0,1; 0,05 e 0,025 mg/Kg, respectively. At forth, fifth and sixth groups, chlorpromazine was used at 1,0; 0,5 and 0,25 mg/Kg, respectively. At seventh, eighth and ninth groups, methotrimeprazine at 1,0; 0,5 and 0,25 mg/Kg was used, respectively. All drugs were administered intravenously. Objects of study: heart rate (HR, non invasive blood pressure (SAP, MAP, DAP, respiratory rate (f, capnography (ETCO2, pulse oxymetry (SatO2, mouth and rectal temperature, bispectral index (BIS, electromyography (EMG%, press and term algimetry. Somatic analgesia was evaluated by animal’s response to nociceptives stimulus. We concluded that chlorpromazine had more hypotension. Dogs showed higher hypnosis level at chlorpromazine group, with evident myorelaxation. All groups showed analgesia to thermic and mechanic stimulus. Acepromazine group showed high duration to both pain stimuli. Bispectral index was shorten at chlorpromazine group at 1,0 mg/kg doses, showing higher hypnosis index, and acepromazine was the less depressing considering the bispectral index.Objetivou-se comparar, em diferentes doses, a acepromazina, a clorpromazina e a levomepromazina com relação às alterações paramétricas, à analgesia avaliada através da presso e termoalgimetria e a condição bispectral em 90 cães sem raça definida alocados em nove grupos. No primeiro, segundo e terceiro grupo foi empregada a acepromazina nas doses de 0,1; 0,05 e 0,025 mg/kg, respectivamente. No quarto, quinto e sexto grupo foi empregada a clorpromazina nas doses de 1,0; 0,5 e 0
14. Comparison of equi-minimum alveolar concentration of sevoflurane and isoflurane on bispectral index values during both wash in and wash out phases: A prospective randomised study
Directory of Open Access Journals (Sweden)
2015-01-01
Full Text Available Background and Aims: At equal minimum alveolar concentration (MAC, volatile agents may produce different bispectral index (BIS values especially at low BIS levels when the effect is volatile agent specific. The present study was performed to compare the BIS values produced by sevoflurane and isoflurane at equal MAC and thereby assessing which is a better hypnotic agent. Methods: Sixty American Society of Anaesthesiologists I and II patients undergoing elective mastoidectomy were divided into groups receiving either isoflurane or sevoflurane, and at equi-MAC. BIS value was measured during both wash in and wash out phase, keeping other parameters same. Statistical analysis was performed using the Friedman two-way analysis and Mann-Whitney U-test. A P < 0.05 was considered significant. Results: BIS value was significantly lower with sevoflurane at all MAC values as compared to isoflurane, except in the beginning and at MAC awake. However, both the drugs proved to be cardiostable. Conclusion: At equi-MAC sevoflurane produces lower BIS values during wash in as well as wash out phase as compared to isoflurane, reflecting probably an agent specific effect and a deficiency in BIS algorithm for certain agents and their interplay.
15. Textile Index Monitor
Institute of Scientific and Technical Information of China (English)
2010-01-01
Part I–Price Index National Index for China Textile City (located in Keqiao, Shaoxing county in Zhejiang Province, east of China) concludes its price index (periodic code:20101101) at 100.31 points rise of 0.68% as against its previous week.
16. Hemodynamics and bispectral index (BIS) of dogs anesthetized with midazolam and ketamine associated with medetomidine or dexmedetomidine and submitted to ovariohysterectomy Avaliação hemodinâmica e do índice bispectral (BIS) de cadelas anestesiadas com midazolam e cetamina associados à medetomidina ou dexmedetomidina e submetidas a ovário-salpingo-histerectomia
OpenAIRE
Fernando do Carmo Silva; Eduardo Hatschbach; Yuri Karaccas de Carvalho; Bruno Watanabe Minto; Flávio Massone; Paulo do Nascimento Junior
2010-01-01
PURPOSE: To evaluate hemodynamics and bispectral index (BIS) in bitches anesthetized with ketamine and midazolam in combination with dexmedetomidine or medetomidine and submitted to ovariohysterectomy. METHODS: Twenty bitches pretreated with levomedetomidine and buprenorphine were anesthetized with 5 mg.kg-1 ketamine and 0.2 mg.kg-1 midazolam i.v. Continuous infusion of 0.4 mg.kg-1.h-1 midazolam and 20 mg.kg-1.h-1 ketamine was initiated in combination with DEX (n=10): 20 µg.kg-1.h-1 dexmedeto...
17. Protocol for the BAG-RECALL clinical trial: a prospective, multi-center, randomized, controlled trial to determine whether a bispectral index-guided protocol is superior to an anesthesia gas-guided protocol in reducing intraoperative awareness with explicit recall in high risk surgical patients
Directory of Open Access Journals (Sweden)
Villafranca Alex
2009-11-01
Full Text Available Abstract Background Awareness with explicit recall of intra-operative events is a rare and distressing complication that may lead to severe psychological symptoms. Candidate depth of anesthesia monitors have been developed, partly with the aim of preventing this complication. Despite conflicting results from clinical trials and the lack of incisive validation, such monitors have enjoyed widespread clinical adoption, in particular the bispectral index. The American Society of Anesthesiologists has called for adequately powered and rigorously designed clinical trials to determine whether the use of such monitors decreases the incidence of awareness in various settings. The aim of this study is to determine with increased precision whether incorporating the bispectral index into a structured general anesthesia protocol decreases the incidence of awareness with explicit recall among a subset of surgical patients at increased risk for awareness and scheduled to receive an inhalation gas-based general anesthetic. Methods/Design BAG-RECALL is a multi-center, randomized, controlled clinical trial, in which 6,000 patients are being assigned to bispectral index-guided anesthesia (target range, 40 to 60 or end-tidal anesthetic gas-guided anesthesia (target range, 0.7 to 1.3 age-adjusted minimum alveolar concentration. Postoperatively, patients are being assessed for explicit recall at two intervals (0 to 72 hours, and 30 days after extubation. The primary outcome of the trial is awareness with explicit recall. Secondary outcomes include postoperative mortality, psychological symptoms, intensive care and hospital length of stay, average anesthetic gas administration, postoperative pain and nausea and vomiting, duration of stay in the recovery area, intra-operative dreaming, and postoperative delirium. Discussion This trial has been designed to complement two other clinical trials: B-Unaware and MACS (ClinicalTrials.gov numbers, NCT00281489 and NCT00689091
18. The effect of different doses of esmolol on hemodynamic, bispectral index and movement response during orotracheal intubation: prospective, randomized, double-blind study
Directory of Open Access Journals (Sweden)
Mensure Yılmaz Çakırgöz
2014-12-01
Full Text Available Objective: A prospective, randomized and double-blind study was planned to identify the optimum dose of esmolol infusion to suppress the increase in bispectral index values and the movement and hemodynamic responses to tracheal intubation. Materials and methods: One hundred and twenty patients were randomly allocated to one of three groups in a double-blind fashion. 2.5 mg kg-1 propofol was administered for anesthesia induction. After loss of consciousness, and before administration of 0.6 mg kg-1 rocuronium, a tourniquet was applied to one arm and inflated to 50 mm Hg greater than systolic pressure. The patients were divided into 3 groups; 1 mg kg-1 h-1 esmolol was given as the loading dose and in Group Es50 50 μg kg-1 min-1, in Group Es150 150 μg kg-1 min-1, and in Group Es250 250 μg kg-1 min-1 esmolol infusion was started. Five minutes after the esmolol has been begun, the trachea was intubated; gross movement within the first minute after orotracheal intubation was recorded. Results: Incidence of movement response and the ΔBIS max values were comparable in Group Es250 and Group Es150, but these values were significantly higher in Group Es50 than in the other two groups. In all three groups in the 1st minute after tracheal intubation heart rate and mean arterial pressure were significantly higher compared to values from before intubation (p < 0.05. In the study period there was no significant difference between the groups in terms of heart rate and mean arterial pressure. Conclusion: In clinical practise we believe that after 1 mg kg-1 loading dose, 150 μg kg-1 min-1 iv esmolol dose is sufficient to suppress responses to tracheal intubation without increasing side effects.
19. 意识指数和脑电双频谱指数监测在小儿全身麻醉诱导中的应用%Index of consciousness and bispectral index in general anaesthesia induction in children
Institute of Scientific and Technical Information of China (English)
金泉英; 刘珺珺; 顾志清
2015-01-01
目的 探讨意识指数(index of consciousness,IoC)在小儿全身麻醉诱导时镇静深度监测中的应用价值.方法 25例择期手术患儿,应用丙泊酚等进行麻醉诱导,麻醉诱导期间测试患儿意识反应,镇静深度采用镇静/警觉评分(observers assessment of alertness/sedation scale,OAA/S),记录OAA/S评分即刻的IoC,并与脑电双频谱指数(bispectral index,BIS)进行比较.结果 25例中有效数据17例;OAA/S为0分时IoC值(44.82±8.47)、BIS值(39.00±14.44)均低于OAA/S为5分时(IoC值为96.65±2.64,BIS值为90.24±5.83),差异有统计学意义(P＜0.01),且以上2个时间点IoC值均大于BIS值(P＜0.05);OAA/S与IoC(r=0.871,P=0.000)、BIS(r=0.864,P=0.000)以及IoC与BIS(r=0.805,P=0.002)均呈正相关.结论 IoC值可反映丙泊酚麻醉诱导期间小儿镇静深度.
20. Angel-6000型脑电麻醉深度监护仪与脑电双频指数临床应用比较%Study of the changes and correlation of index of consciousness and bispectral index during target-controlled infusion of propofol
Institute of Scientific and Technical Information of China (English)
李鹏; 徐广民; 范丹
2015-01-01
Objective: To study the changes of correlation between index of consciousness (IoC) and bispectral index (BIS) during target-controlled infusion of propofol. Methods: IoC and BIS of 35 patients undering laparoscopic cholecystectomy under general anesthesia were monitored simultaneously. Anesthesia was induced with TCI propofol. When the plasma propofol concentration increased from 1.5 μg/ml to 4μg/ml, The changes and corredation of IoC and BIS were compared in basic state at the, loss and recovery of consciousness and during intubation. Result: There was no significant difference in basic IoC and BIS (P > 0.05). When patients were at the loss and recovery of consciousness, the IoC and BIS were lower than the basic value (P 0.05),意识消失与意识恢复时两者均低于基础值(P0.05)，与BIS(42.7±6.65)比较差异有统计学意义(P<0.05)。不同浓度时BIS与loC值的相关系数r为0.971(P<0.01)，两者具有显著相关性。插管时IoC为55±5.37，高于插管前，并高于同期BIS值(P<0.05)。结论：丙泊酚TCI实施全身麻醉时IoC能良好地反映患者意识水平，与BIS具有良好的相关性，能够实时反映气管插管刺激对于脑电的影响。
1. 意识指数与脑电双频指数监测靶控丙泊酚全麻诱导时镇静深度的比较%Comparison between the index of consciousness and the bispectral index during propofol target-controlled infusion anaesthesia induction
Institute of Scientific and Technical Information of China (English)
辛鑫; 赵晶; 黄宇光
2011-01-01
目的 探讨意识指数(IOC)与脑电双频指数(BIS)相比,靶控丙泊酚全麻诱导时用于监测镇静深度的相关性.方法 纳入行基本外科或妇产科手术的患者30例,靶控丙泊酚全麻诱导期间,同时监测IOC和BIS.记录镇静评分(OAA/S)由5分逐级降低至1分时,每次OAA/S评分即刻的IOC及BIS值,以及相应点的丙泊酚效应室浓度.结果 与基线值比较,OAA/S评分从5逐渐降低至1时,BIS与IOC值均降低,BIS值之间或IOC值之间的差异均有统计学意义(P＜0.05).结论 IOC用于靶控丙泊酚全麻诱导时的镇静深度监测,与BIS具有良好的相关性.%Objective To compare a new level of consciousness monitor, called the index of consciousness (IOC) with the bispectral index (BIS) during propofol target-controlled infusion (TCI) anaesthesia induction. Methods After ethical committee approval and written patient consent, data from 30 patients were recorded. All patients were induced with propofol target-controlled infusion ( TCI) , until the Observer's Assessment of Alertness and Sedation (OAAS) scale level 1 was reached, and then IOC and BIS were calculated during OAAS 5 - 1. Results With the increase of sedation during OAAS 5 ～ 1, there was a significant decrease of BIS and IOC ( P < 0. 05 ). Conclusions IOC has a close correlation with BIS during propofol target-controlled infusion (TCI) anaesthesia induction.
2. Hemodynamics and bispectral index (BIS of dogs anesthetized with midazolam and ketamine associated with medetomidine or dexmedetomidine and submitted to ovariohysterectomy Avaliação hemodinâmica e do índice bispectral (BIS de cadelas anestesiadas com midazolam e cetamina associados à medetomidina ou dexmedetomidina e submetidas a ovário-salpingo-histerectomia
Directory of Open Access Journals (Sweden)
Fernando do Carmo Silva
2010-04-01
3. Effect of intravenous lidocaine on bispectral index and stress reaction in patients undergo tracheal intubation%静脉注射利多卡因对气管插管病人BIS值及应激反应的影响
Institute of Scientific and Technical Information of China (English)
王红珠; 陈冯琳; 王明仓
2011-01-01
AIM:To observe the relationship between the level of catecholamine with bispec-tral index during endotracheal intubation with propofol anesthesia in order to investigate the mechanism of the preventing of endotracheal intubation response with lidocaine. METHODS: Sixty patients were randomly allocated into two groups:control group (Group C) and lidocaine group (Group L). The patients received lidocaine 1. 5 mg/kg in Group L and saline in Group C before induction of anesthesia. Anesthesia was induced with propofol (2 mg/kg) and fentanyl (4 jug/kg) and tracheal intubation was facilitated with rocuronium (0.6 mg/kg) in all patients. Bispectral index (BIS), systolic pressure ( SP) , diastolic pressure(DP) and heart rate(HR)were continuously monitored and recorded before induced of anesthesia(T0) , preintubation(T!) , immediately and 1,3 min after intubation (T2-4). Arterial blood samples were obtained at To? Tj and T3 for determination of plasma concentration of adrenaline (Ad) and noradrenaline(NA). RE-SULTS :SP, DP,HR were significantly increased after intubation in Group C compared with baseline values at T0 ( P 0. 05). Compared with Group C, BIS value at Ti to T4 decreased significantly in Group L(P<0. 05). Plasma Ad and NA were lower at T3 in Group L than those in Group C and T0(P<0. 05). CONCLUSION: Lidocaine can further reduce BIS value and the plasma concentration of catecholamines during propofol anesthesia, indicating the sedative and anti-nociep-tive effect of intravenous lidocaine. Lidocaine (1. 5 mg/kg) can restrain the changes of BIS and reduce stress reaction caused by tracheal intubation.%目的:观察利多卡因对丙泊酚麻醉诱导气管插管时血浆儿茶酚胺与脑电双频指数(BIS)变化的影响,探讨利多卡因抑制气管插管反应的机制.方法:60例患者随机分为对照组(C组)和利多卡因组(L组).L组先静脉注射利多卡因1.5 mg/kg,C组注入等量生理盐水,然后两组均静脉注射丙泊酚2 mg/kg、芬太尼4
4. Fiber optic refractive index monitor
Science.gov (United States)
Weiss, Jonathan David
2002-01-01
A sensor for measuring the change in refractive index of a liquid uses the lowest critical angle of a normal fiber optic to achieve sensitivity when the index of the liquid is significantly less than the index of the fiber core. Another embodiment uses a liquid filled core to ensure that its index is approximately the same as the liquid being measured.
5. General methods for constructing bispectral operators
CERN Document Server
Bakalov, B N; Yakimov, M T
1996-01-01
We present methods for obtaining new solutions to the bispectral problem. We achieve this by giving its abstract algebraic version suitable for generalizations. All methods are illustrated by new classes of bispectral operators.
6. Capnography and the Bispectral Index—Their Role in Pediatric Sedation: A Brief Review
Directory of Open Access Journals (Sweden)
Maria Sammartino
2010-01-01
Full Text Available Sedation in children is increasingly emerging as a minimally invasive technique that may be associated with local anaesthesia or diagnostic and therapeutic procedures which do not necessarily require general anaesthesia. Standard monitoring requirements are not sufficient to ensure an effective control of pulmonary ventilation and deep sedation. Capnography in pediatric sedation assesses the effect of different drugs on the occurrence of respiratory failure and records early indicators of respiratory impairment. The Bispectral index (BIS allows the reduction of dose requirements of anaesthetic drugs, the reduction in the time to extubation and eye opening, and the reduction in the time to discharge. In the field of pediatric sedation, capnography should be recommended to prevent respiratory complications, particularly in spontaneous ventilation. The use of the BIS index, however, needs further investigation due to a lack of evidence, especially in infants. In this paper, we will investigate the role of capnography and the BIS index in improving monitoring standards in pediatric sedation.
7. Comparação dos valores do índice bispectral em pacientes com paralisia cerebral em estado de vigília Comparación de los valores del índice bispectral en pacientes con parálisis cerebral en estado de vigilia Comparison of the bispectral index in awake patients with cerebral palsy
Directory of Open Access Journals (Sweden)
Verônica Vieira da Costa
2007-08-01
8. Bispectral algebras of commuting ordinary differential operators
CERN Document Server
Bakalov, B N; Yakimov, M T
1997-01-01
We develop a systematic way for constructing bispectral algebras of commuting ordinary differential operators of any rank N. It enables us to obtain all previously known classes or examples of bispectral operators. The suggested method is completely algorithmic, which allows us to present explicitly new examples. We conjecture that the class built in the present paper exhausts all bispectral scalar operators. This paper is the third of a series of papers (hep-th/9510211, q-alg/9602010, q-alg/9602012) on the bispectral problem.
9. Regressão da anestesia geral em pacientes com paralisia cerebral: estudo comparativo utilizando o índice bispectral Regresión de la anestesia general en pacientes con parálisis cerebral: estudio comparativo utilizando el índice bispectral Regression of general anesthesia in patients with cerebral palsy: a comparative study using the bispectral index
Directory of Open Access Journals (Sweden)
Verônica Vieira da Costa
2006-10-01
pacientes del grupo control estaba en el estadio III de regresión anestésica, versus 29% del grupo con parálisis cerebral. A los treinta minutos, el 72% de los pacientes del grupo control estaba apto para recibir el alta, estadio IV de regresión anestésica, versus 41,9% de los pacientes con PC. CONCLUSIONES: Los pacientes con parálisis cerebral presentaron un regreso más lento de la conciencia en comparación con el grupo control.BACKGROUND AND OBJECTIVES: It has been said that patients with cerebral palsy (CP present a higher sensitivity to anesthetic agents, which may affect adversely the awakening from anesthesia. The objective of this study was to evaluate the recovery of patients with CP compared with patients without CNS disease. METHODS: The study population was composed of children ages 5 to 15, divided in two groups: those with a diagnosis of cerebral palsy and those without CNS disease. All of them underwent general anesthesia with sevoflurane associated with nitrous oxide and 50% oxygen. Besides the parameters commonly monitored, they also underwent EEG-BIS monitoring. Regression of general anesthesia during awakening from anesthesia, tracheal extubation, and the immediate postanesthetic period were evaluated according to the criteria adopted by Saraiva. The speed of elimination of the anesthetic agents was also evaluated, correlating it with the EEG-BIS values, and comparing the two groups of patients. Statistical analysis was done through exploratory analysis of the data and statistical testing comparing the means. The statistical difference was considered significant for values of p smaller or equal to 5%. RESULTS: Fifty-six patients were evaluated: 31 with CP and 25 without CNS disease. Both groups were homogenous regarding age and gender. Baseline EEG-BIS values for CP patients were smaller than those for the control group, and this difference was statistically significant (p = 0.04. During the first five minutes after discontinuation of sevoflurane
10. Comparative study among acepromazine, chlorpromazine and methotrimeprazine in different doses, through bispectral index, term and pressure algimetry, in dogs /
Estudo comparativo entre a acepromazina, clorpromazina e levomepromazina em diferentes doses, através do exame bispectral, termo e pressoalgimetria, em cães
OpenAIRE
Lidia Mitsuko Matsubara; Flávio Massone; Raquel Cristina Gonçalves
2009-01-01
The study’s objective was to realize comparisons among different acepromazine, chlorpromazine and methotrimeprazine doses, evaluate parametric changes, test analgesia using press and term algimetry, and evaluate bispectral condition. 90 mongrel dogs were used, male and female, adult, weighting 10 to 15 Kg as a rule, distributed in 9 groups with 10 animals each. At first, second and third groups acepromazine was used at 0,1; 0,05 e 0,025 mg/Kg, respectively. At forth, fifth and sixth groups, c...
11. The relationship between the Bispectral Index (BIS) and the Observer Alertness of Sedation Scale (OASS) scores during propofol sedation with and without ketamine: a randomized, double blinded, placebo controlled clinical trial.
Science.gov (United States)
De Oliveira, Gildasio S; Kendall, Mark C; Marcus, R-Jay; McCarthy, Robert J
2016-08-01
Prior studies have examined the static effect of intravenous ketamine on the BIS Index for sedation but it remains unknown if the BIS Index is a reliable method to track sedation levels in the presence of ketamine. The major objective of the current investigation was to compare the BIS Vista Index ability to track varying depths of sedation as determined by OASS scores in a standardized anesthetic regimen with and without ketamine. The study was a randomized, double blinded clinical trial. Patients undergoing breast surgery under sedation with propofol were randomized to receive ketamine (1.5 μg kg min(-1)) or saline. Infusion data was used to estimate propofol plasma concentrations (Cp). The main outcome of interest was the correlation between the BIS Vista Index with the OASS score. Twenty subjects were recruited and fifteen completed the study. Four hundred fifty-five paired data points were included in the analysis. Model performance (Nagelkerke R(2)) of the multinomial logistic regression model was 0.57 with the c-statistic of 0.87 (95 % CI 0.82-0.91). Compared to awake the odds ratio for BIS values predicting moderate sedation in the saline/propofol group 1.19 (95 % CI 1.12-1.25) but only 1.06 (95 % CI 1.02-1.1) in the ketamine/propofol group (P = 0.001). There was no difference in the odds for BIS values to predict deep sedation between groups (P = 0.14). The BIS monitor can be used to monitor sedation level even when ketamine is used with propofol as part of the sedation regimen. However, ketamine reduces the value of the BIS in predicting moderate sedation levels. PMID:26219614
12. Midazolam por via oral como medicação pré-anestésica em crianças e adolescentes com paralisia cerebral: estudo comparativo das variações do índice bispectral Midazolam por vía oral como medicación preanestésica en niños y adolescentes con parálisis cerebral: estudio comparativo de las variaciones del índice bispectral Oral midazolam as pre-anesthetic medication in children and teenagers with cerebral palsy: a comparative study on the variations of the bispectral index
Directory of Open Access Journals (Sweden)
Verônica Vieira da Costa
2009-02-01
13. Effect of esmolol on bispectral index in patients undergoing orotracheal intubation during induction of anesthesia%艾司洛尔对患者麻醉诱导气管插管时脑电双频谱指数的影响
Institute of Scientific and Technical Information of China (English)
曹德权; 陈艳平; 张燕玲
2010-01-01
Objective To evaluate the effect of esmolol on bispectral index (BIS) in patients undergoing orotracheal intubation during induction of anesthesia and to investigate the mechanism of inhibiting the cardiovascular responses to tracheal intubation.Methode Forty patients in physical status of ASA Ⅰ or Ⅱ and aged 20-60 years were randomly divided into 2 groups ( n = 20 each): esmolol group (group E) and control group (group C). Anesthesia was induced with midazolam 0.1 mg/kg, fentanyl 5 μg/kg and vecuronium 0.1 mg/kg. In group E, esmolol 1 mg/kg was given intravenously before anesthesia induction and followed by an infusion of esmolol 250 μg· kg- 1·min-1, while a comparable volume of saline was given for group C. Mean arterial pressure (MAP), heart rate (HR) and BIS were recorded before esmolol administration, before induction of anesthesia, before orotracheal intubation, and at 1, 2 and 5 min after intubation, respectively.Results There were no significant differences in HR, MAP and BIS between the two groups before tracheal intubation. HR and MAP significantly increased after tracheal intubation in both groups, but BIS only in group C significantly increased after intubation.HR, MAP and BIS were significantly lower after intubation in group E than in group C ( P＜ 0.05).Conclusion Esmolol can decrease BIS during tracheal intubation and its antinociceptive property is related to the mechanism of inhibiting cardiovascular responses to tracheal intubation.
14. Role of Bispectral Index for Guiding Propofol Dosage in Drug Abuse Patients Undergoing Painless Induced A-bortion%B IS 对吸毒患者无痛人流术中丙泊酚用量的指导作用
Institute of Scientific and Technical Information of China (English)
廖孝芸; 孔高茵; 叶昉帆
2014-01-01
【目的】通过监测吸毒患者无痛人工流产（人流）术中的脑电双频指数（BIS ）寻找适合吸毒患者的丙泊酚用量。【方法】随机选取2009年至2013年在本院行无痛人流术的20例吸毒患者为试验组，并随机选取20例行无痛人流术非吸毒患者为对照组。术前查人绒毛膜促性腺激素（HCG ）均为阳性；B超确诊宫内妊娠。禁食禁饮4～6 h。入室后取截石位，两组患者均连接BIS监测仪于正确的位置，并连接丙泊酚TCI泵，起始血浆靶控浓度均为4μg/mL ，根据BIS值和血流动力学以及患者体动，以每次0．3～0．5μg/mL调整靶控浓度。待BIS维持在45～60之间，睫毛反射消失/钳夹宫口无体动，开始手术。并记录麻醉前（T0）、睫毛反射消失/钳夹宫口无体动（T1）、扩开宫口后开始清宫（T2）、术毕（T3）、麻醉苏醒时（T4）的平均动脉压（MBP）、心率（HR）、血氧饱和度（SpO2）以及BIS。术后查看丙泊酚 TCI泵，记录患者丙泊酚的总用量以及维持血浆靶控浓度。记录体动例数、呼吸抑制例数、手术时间以及苏醒时间。【结果】在相同的BIS值麻醉深度下，试验组的丙泊酚的用量为（179±51）mg明显大于对照组（124±27）mg ；而苏醒时间明显小于对照组，且两组相比较差异有显著性（3．2±2．1vs4．3±1．9，P ＜0．05），两组手术时间、患者体动次数、呼吸抑制例数相比较差异无显著性（ P＞0．05）。【结论】单纯丙泊酚麻醉无痛人流术中，吸毒患者术中维持血浆靶控浓度约为（6．8±1．4）μg/mL。丙泊酚的用量显著大于非吸毒患者，而苏醒时间明显短于非吸毒患者。%Objective To monitor bispectral index (BIS) of drug abuse patients undergoing painless induced abortion in or-der to find proper propofol dosage for drug abuse patients .[Methods]A total of 20 drug abuse patients undergoing painless
15. Quality assurance: using the exposure index and the deviation index to monitor radiation exposure for portable chest radiographs in neonates
International Nuclear Information System (INIS)
Many methods are used to track patient exposure during acquisition of plain film radiographs. A uniform international standard would aid this process. To evaluate and describe a new, simple quality-assurance method for monitoring patient exposure. This method uses the ''exposure index'' and the ''deviation index,'' recently developed by the International Electrotechnical Commission (IEC) and American Association of Physicists in Medicine (AAPM). The deviation index measures variation from an ideal target exposure index value. Our objective was to determine whether the exposure index and the deviation index can be used to monitor and control exposure drift over time. Our Agfa workstation automatically keeps a record of the exposure index for every patient. The exposure index and deviation index were calculated on 1,884 consecutive neonatal chest images. Exposure of a neonatal chest phantom was performed as a control. Acquisition of the exposure index and calculation of the deviation index was easily achieved. The weekly mean exposure index of the phantom and the patients was stable and showed <10% change during the study, indicating no exposure drift during the study period. The exposure index is an excellent tool to monitor the consistency of patient exposures. It does not indicate the exposure value used, but is an index to track compliance with a pre-determined target exposure. (orig.)
16. Quality assurance: using the exposure index and the deviation index to monitor radiation exposure for portable chest radiographs in neonates
Energy Technology Data Exchange (ETDEWEB)
Cohen, Mervyn D. [Indiana University School of Medicine, Department of Radiology, Riley Children' s Hospital, Indianapolis, IN (United States); Riley Hospital for Children, Department of Radiology, Indianapolis, IN (United States); Cooper, Matt L.; Piersall, Kelly [Indiana University School of Medicine, Department of Radiology, Riley Children' s Hospital, Indianapolis, IN (United States); Apgar, Bruce K. [Agfa HealthCare Corporation, Greenville, SC (United States)
2011-05-15
Many methods are used to track patient exposure during acquisition of plain film radiographs. A uniform international standard would aid this process. To evaluate and describe a new, simple quality-assurance method for monitoring patient exposure. This method uses the ''exposure index'' and the ''deviation index,'' recently developed by the International Electrotechnical Commission (IEC) and American Association of Physicists in Medicine (AAPM). The deviation index measures variation from an ideal target exposure index value. Our objective was to determine whether the exposure index and the deviation index can be used to monitor and control exposure drift over time. Our Agfa workstation automatically keeps a record of the exposure index for every patient. The exposure index and deviation index were calculated on 1,884 consecutive neonatal chest images. Exposure of a neonatal chest phantom was performed as a control. Acquisition of the exposure index and calculation of the deviation index was easily achieved. The weekly mean exposure index of the phantom and the patients was stable and showed <10% change during the study, indicating no exposure drift during the study period. The exposure index is an excellent tool to monitor the consistency of patient exposures. It does not indicate the exposure value used, but is an index to track compliance with a pre-determined target exposure. (orig.)
17. The effects of low-dose ketamine on the analgesia nociception index (ANI) measured with the novel PhysioDoloris™ analgesia monitor: a pilot study.
Science.gov (United States)
Bollag, Laurent; Ortner, Clemens M; Jelacic, Srdjan; Rivat, Cyril; Landau, Ruth; Richebé, Philippe
2015-04-01
The PhysioDoloris™ analgesia monitor assesses nociception effects on the autonomic nervous system by analyzing changes in heart rate variability (HRV). This non-invasive device analyses ECG signals and determines the analgesia nociception index (ANI), allowing for quantitative assessment of the analgesia/nociception balance in anesthetized patients. Ketamine, an analgesic adjuvant with sympathomimetic properties, has been shown to improve perioperative pain management. The purpose of this pilot study was to evaluate whether low-dose ketamine, due to its intrinsic effect on the sino-atrial node, affects HRV and, therefore, interferes with ANI measurements. This pilot study included 20 women undergoing abdominal hysterectomies. Anesthesia and analgesia were maintained with sevoflurane and fentanyl respectively, in a standardized manner. Five minutes after intubation, 0.5 μg kg(-1) of intravenous (i.v.) ketamine was administered. ANI, bispectral index (BIS), heart rate and blood pressure were recorded from the induction of anesthesia until 5 min after skin incision. There was not any significant decrease in mean (±SD) ANI values after intubation (2.11±20.11, p=0.35) or i.v. ketamine administration (1.31±15.26, p=0.28). The mean (±SD) reduction in ANI values after skin incision was statistically significant (13.65±15.44, p=0.01), which is consistent with increased nociception. A single i.v. bolus of 0.5 μg kg(-1) ketamine did not influence the ANI values of 20 women under standardized general anesthesia conditions and absent noxious stimulation. These results suggest that the ANI derived from the PhysioDoloris™ analgesia monitor is feasible under such clinical conditions. PMID:25062948
18. Highest weight modules of W$_{1+\\infty}$, Darboux transformations and the bispectral problem
CERN Document Server
Bakalov, B N; Yakimov, M T
1996-01-01
We announce a systematic way for constructing bispectral algebras of commuting differential operators of any rank N. It enables us to obtain all previously known classes and examples of bispectral operators. Moreover, we give a representation-theoretic explanation of the results including those of Duistermaat and Gr\\"unbaum. The manifold of bispectral operators of any order is preserved by an hierarchy of symmetries. We point out that our methods provide a completely algorithmic procedure for obtaining bispectral algebras. We conjecture that the class built in the present paper exhausts all bispectral scalar operators. The proofs and details will appear in our subsequent papers.
19. Effects of penehyclidine as preanesthetic medication on hemodynamics and bispectral index in patients undergoing coronary artery bypass grafting surgery%麻醉前应用戊乙奎醚对冠脉搭桥术患者血流动力学和脑电双频指数的影响
Institute of Scientific and Technical Information of China (English)
方波; 马虹
2011-01-01
目的:观察冠脉搭桥术麻醉前应用戊乙奎醚对麻醉诱导前后患者血流动力学和脑电双频指数(BIS)的影响.方法:择期全麻下行冠脉搭桥术患者40例,随机分为2组,每组20例.戊乙奎醚组麻醉诱导前肌内注射(肌注)戊乙奎醚0.01 mg·kg(-1),东莨菪碱组肌注东莨菪碱0.006 mg·kg(-1).观察比较2组麻醉诱导前后心率、血压、心率收缩压乘积(RPP)和BIS值.结果:东莨菪碱组用药后收缩压和RPP无明显变化,用药后20 min患者心率有所上升,用药后10、20 min BIS值有所下降,但高于戊乙奎醚组(P<0.05).戊乙奎醚组用药后10、20 min,患者心率、血压、RPP和BIS值均降低(P<0.05).气管插管前后戊乙奎醚组心率、收缩压、RPP和BIS值多低于东莨菪碱组.2组均未见明显不良反应.结论:应用戊乙奎醚作为冠脉搭桥术前用药,可降低心肌耗氧量,有利于患者血流动力学平稳和镇静.%AIM To evaluate the effects of penehyclidine as a preanesthetic medication on hemodynamics and bispectral index (BIS) in patients undergoing coronary artery bypass grafting surgery. METHODS A total of 40 patients scheduled for coronary artery bypass grafting under general anesthesia were randomly divided into two groups (n = 20 for each group) , and were intramuscularly injected with penehyclidine 0.01 mg-kg"1 in penehyclidine group and scopolamine 0.006 mg'kg"1 in scopolamine group respectively before general anesthesia. Heart rate ( HR) , blood pressure ( BP) and BIS were measured, and rate pressure product ( RPP) was calculated. RESULTS There were no significant changes of SBP and RPP in the scopolamine group, but HRtended to increase 20 min after administration. BIS in the scopolamine group were deceased 10 and 20 min after administration, but were higher than that in penehyclidine group (P < 0.05). The HR, BP, RPP and BIS were decreased 10 and 20 min after intramuscular injection of penehyclidine (P < 0.05). And the HR, BP, RPP and
20. On the Performance and Estimation of Spectral and Bispectral Analysis of Time Series Data
OpenAIRE
J.F. Ojo
2008-01-01
In this study, discrete spectral and bi-spectral analysis of time series data were considered to determine which of them perform better. The parameters of the spectral and bi-spectral models were estimated using Modified Newton Raphson Iterative method. Since the order of a model cannot be increased indiscriminately because of the closeness of some parameters to zero; discrete spectral and bi-spectral analysis model of orders one to five were fitted to the real series. Akaike Informatio...
1. ATLAS EventIndex monitoring system using the Kibana analytics and visualization platform
CERN Document Server
Barberis, Dario; The ATLAS collaboration; Favareto, Andrea; Fernandez Casani, Alvaro; Gallas, Elizabeth; Garcia Montoro, Carlos; Gonzalez de la Hoz, Santiago; Hrivnac, Julius; Malon, David; Prokoshin, Fedor; Salt, Jose; Sanchez, Javier; Toebbicke, Rainer; Yuan, Ruijun
2016-01-01
The ATLAS EventIndex is a data catalogue system that stores event-related metadata for all (real and simulated) ATLAS events, on all processing stages. As it consists of different components that depend on other applications (such as distributed storage, and different sources of information) we need to monitor the conditions of many heterogeneous subsystems, to make sure everything is working correctly. This paper describes how we gather information about the EventIndex components and related subsystems: the Producer-Consumer architecture for data collection, health parameters from the servers that run EventIndex components, EventIndex web interface status, and the Hadoop infrastructure that stores EventIndex data. This information is collected, processed, and then displayed using CERN service monitoring software based on the Kibana analytic and visualization package, provided by CERN IT Department. EventIndex monitoring is used both by the EventIndex team and ATLAS Distributed Computing shifts crew
2. Efeitos de diferentes frações inspiradas de oxigênio no índice biespectral em cães submetidos à infusão contínua de propofol Effects of several inspired oxygen fractions on the bispectral index in dogs submitted to continuous infusion of propofol
Directory of Open Access Journals (Sweden)
P.C.F. Lopes
2008-04-01
3. 舒芬太尼复合艾司洛尔对腹腔镜胆囊切除术二氧化碳气腹期间的影响%Impact of Sufentanil Combined with Esmolol on Cardiovascular Responses and Bispectral Index during CO2 Pneumoperitoneum in Laparoscopic Cholecystectomy
Institute of Scientific and Technical Information of China (English)
舒华
2012-01-01
Objective To evaluate the impact of sufentanil combined with esmolol on cardiovascular responses and bispectral index (BIS) during CO2 pneumoperitoneum in laparoscopic cholecystectomy. Methods From January 2010 to December 2011, 90 elective laparoscopic cholecystectomy patients with ASA grade I - II were randomly divided into the fentanyl group (group I), sufentanil group (group II ) and sufentanil combined with esmolol group (group III ). Endotracheal intubation and mechanical ventilation were performed after patients in group I used fentanyl (4 μg/kg), and group II and III patients used sufentanil (0.6 μg/kg) to induce anesthesia. Patients in group III used esmolol before pneumoperitoneum was established. Patients in all the three groups were regularly administered midazolam (0.1 mg/kg), propofol (2 mg/kg) and vecuronium (0.1 mg/kg) through intravenous injection. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), oxygen saturation (SpO2) and BIS at the moment of T1 (before establishing pneumoperitoneum), T2, T3 and T4 (separately at 30 seconds, 5 minutes and 15 minutes after establishing pneumoperitoneum) in each group were recorded and analyzed. Results At T1, the SBP, DBP, HR and BIS of group III patients were the lowest in the three groups, but the differences were not significant among the three groups (P > 0.05). At T2, T3, and T4, the SBP, DBP, HR and BIS significantly increased in group I , increased in group II and did not significantly change in group III. There were significant differences between group I and group II , and between group II and group III (P < 0.05). Conclusion Sufentanil combined with esmolol can be better to prevent laparoscopic cholecystectomy cardiovascular responses during CO2 pneumoperitoneum and inhibit the increase in BIS.%目的 评价舒芬太尼复合艾司洛尔对腹腔镜胆囊切除术二氧化碳气腹期间心血管反应和脑电
4. Multi-Index Monitoring and Evaluation on Rock Burst in Yangcheng Mine
OpenAIRE
Yunliang Tan; Yanchun Yin; Shitan Gu; Zhiwei Tian
2015-01-01
Based on the foreboding information monitoring of the energy released in the developing process of rock burst, prediction system for rock burst can be established. By using microseismic method, electromagnetic radiation method, and drilling bits method, rock burst in Yangcheng Mine was monitored, and a system of multi-index monitoring and evaluation on rock burst was established. Microseismic monitoring and electromagnetic radiation monitoring were early warning method, and drilling bits moni...
5. Evaluation of Three MODIS-Derived Vegetation Index Time Series for Dryland Vegetation Dynamics Monitoring
OpenAIRE
Linlin Lu; Claudia Kuenzer; Cuizhen Wang; Huadong Guo; Qingting Li
2015-01-01
Understanding the spatial and temporal dynamics of vegetation is essential in drylands. In this paper, we evaluated three vegetation indices, namely the Normalized Difference Vegetation Index (NDVI), the Soil-Adjusted Vegetation Index (SAVI) and the Enhanced Vegetation Index (EVI), derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) Surface-Reflectance Product in the Xinjiang Uygur Autonomous Region, China (XUAR), to assess index time series’ suitability for monitoring vege...
6. Ação do anticonvulsivante isolado e associado ao midazolam como medicação pré-anestésica sobre o índice bispectral (BIS em pacientes com paralisa cerebral Acción del antiepiléptico aislado y asociado al midazolam como medicación preanestésica sobre el índice bispectral (BIS en pacientes con parálisis cerebral Effect of isolated anticonvulsant drug use and associated to midazolam as pre-anesthetic medication on the bispectral index (BIS in patients with cerebral palsy
Directory of Open Access Journals (Sweden)
Verônica Vieira da Costa
2010-06-01
7. Influência da dexmedetomidina na concentração expirada do sevoflurano: avaliação pelo índice bispectral, taxa de supressão e análise espectral da potência do eletroencefalograma Influencia de la dexmedetomidina en la concentración expirada del sevoflurano: evaluación por el índice bispectral, tasa de supresión y análisis espectral de la potencia del eletroencefalograma Influence of dexmedetomidine upon sevoflurane end-expiratory concentration: evaluation by bispectral index, suppression rate and electroencephalographic power spectral analysis
Directory of Open Access Journals (Sweden)
Rogean Rodrigues Nunes
2002-04-01
del sexo femenino, estado físico ASA I, sometidas a laparoscopia ginecológica bajo anestesia general mantenida con sevoflurano, divididas aleatoriamente en dos grupos: Grupo I (20: sin dexmedetomidina, y Grupo II (20: con dexmedetomidina en infusión continua en el siguiente esquema: Fase rápida (1 µg.kg-1 en 10 minutos, 10 minutos antes de la inducción de la anestesia, seguida por un periodo de manutención (0,4 µg.kg-1.h-1 hasta el final de la cirugía. Fueron analizados los siguientes parámetros: PA, FC, BIS, SEF 95%, amplitud relativa en la frecuencia de banda delta (delta%, tasa de supresión (TS, rSO2, CE, SpO2 yP ET CO2, en los siguientes momentos: M1 - antes de la infusión de la dexmedetomidina o solución fisiológica a 0,9%, M2: antes de la intubación traqueal (IT, M3: después a IT, M4: antes de la incisión, M5: después de la incisión, M6: antes de la insuflación de CO2, M7: después de la insuflación de CO2, M8: 10 minutos después de la insuflación de CO2, M9: 10 min. después M8, M10: 20 min después M8, M11: 30 min después M8, M12: 40 min después M8 y M13: al despertar. Anotamos también el tiempo de despertar y de alta hospitalar. RESULTADOS: La dexmedetomidina redució la concentración expirada de sevoflurano de M4 hasta M13 (p BACKGROUND AND OBJECTIVES: Dexmedetomidine, an alpha2-adrenergic agonist, has been described as being able to decrease the demand for both venous and inhalational agents. This study aimed at evaluating the influence of Dexmedetomidine upon sevoflurane end-expiratory concentration (EC with monitoring the depth of anesthesia. METHODS: Participated in this study 40 female adult patients, physical status ASA I, submitted to gynecological laparoscopy under general anesthesia maintained with sevoflurane, who were randomly divided in two groups: Group I (n=20, without dexmedetomidine; and Group II (n=20, with dexmedetomidine, in continuous infusion, as follows: Rapid phase (1 µg.kg-1 in 10 min-1 10 minutes before
8. ATLAS EventIndex monitoring system using Kibana analytics and visualization platform
CERN Document Server
Barberis, Dario; The ATLAS collaboration; Prokoshin, Fedor; Gallas, Elizabeth; Favareto, Andrea; Hrivnac, Julius; Sanchez, Javier; Fernandez Casani, Alvaro; Gonzalez de la Hoz, Santiago; Garcia Montoro, Carlos; Salt, Jose; Malon, David; Toebbicke, Rainer; Yuan, Ruijun
2016-01-01
The ATLAS EventIndex is a data catalogue system that stores event-related metadata for all (real and simulated) ATLAS events, on all processing stages. As it consists of different components that depend on other applications (such as distributed storage, and different sources of information) we need to monitor the conditions of many heterogeneous subsystems, to make sure everything is working correctly. This information is collected, processed, and then displayed using CERN service monitoring software based on the Kibana analytic and visualization package, provided by CERN IT Department. EventIndex monitoring is used both by the EventIndex team and ATLAS Distributed Computing shifts crew.
9. Innovation index for monitoring national innovation systems of Russia and the EU
OpenAIRE
Volkova N.N.; Romanyuk E.I.
2011-01-01
Innovation index for monitoring national innovation systems of Russia and the EU. Abstract This article focuses on the innovative aspects of monitoring national innovation system. It is based on previous work the authors “Methodic for monitoring the national innovation system of the Russian Federation and international comparisons of innovation ", but more profoundly affect the investment unit of the system for monitoring the national innovation system. Design and analysis of components of th...
10. Bi-spectral extraction through elliptic neutron guides
Energy Technology Data Exchange (ETDEWEB)
Jacobsen, Henrik, E-mail: [email protected] [Nanoscience center and eScience center, Niels Bohr Institute, University of Copenhagen (Denmark); ESS design update program (Denmark); Lieutenant, Klaus; Zendler, Carolin [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); ESS design update program (Germany); Lefmann, Kim [Nanoscience center and eScience center, Niels Bohr Institute, University of Copenhagen (Denmark); ESS design update program (Denmark)
2013-07-21
In this paper we present the results of investigating a suggested guide extraction system utilizing both a thermal and a cold moderator at the same time, the so-called bi-spectral extraction. Here, the thermal moderator has line of sight to the sample position, and the neutrons from the cold source are reflected by a supermirror towards the sample. The work is motivated by the construction of the European Spallation Source (ESS) but the results are general and can be used at any neutron source. Due to the long pulse structure, most instruments at ESS will be long, often exceeding 50 m from moderator to detector. We therefore investigate the performance of bi-spectral extraction for instrument lengths of 30 m, 56 m, 81 m and 156 m. In all these cases, our results show that we can utilize both moderators (and thus high intensity in a wide wavelength band) in the same instrument at a cost of flux of 5–30% for neutrons with wavelength larger than 1 Å. In general, the divergence distribution is smooth at the sample position for all wavelengths. -- Highlights: • We simulate bi-spectral neutron beam extraction through elliptic guides. • Two independent ray-tracing tools (McStas and VITESS) give similar results. • Brilliance transfers of 70–95% for λ>1Å are achieved for guide lengths of 30–156 m. • The beam profile is smooth at the sample position. • The simulations are performed with ESS in mind, but have general validity.
11. Highest weight modules over W$_{1+\\infty}$ algebra and the bispectral problem
CERN Document Server
Bakalov, B N; Yakimov, M T
1996-01-01
The present paper establishes a connection between the Lie algebra W_{1+infty} and the bispectral problem. We show that the manifolds of bispectral operators obtained by Darboux transformations on powers of Bessel operators are in one to one correspondence with the manifolds of tau-functions lying in the W_{1+infty}-modules M_beta introduced in our previous paper hep-th/9510211. An immediate corollary is that they are preserved by hierarchies of symmetries generated by subalgebras of W_{1+infty}. This paper is the last of a series of papers (hep-th/9510211, q-alg/9602010, q-alg/9602011) on the bispectral problem.
12. To clarify features of photoplethysmography in monitoring balanced anesthesia, compared with Cerebral State Index
OpenAIRE
Zhang, Lieliang; Xu, Lei; Zhu, Juan; Gao, Yujie; Luo, Zhonghua; Wang, Hongyu; Zhu, Zhongliang; Yu, Yi; Shi, Hongwei; Bao, Hongguang
2014-01-01
Background Although photoplethysmography and cerebral state index (CSI) have been used as indices in monitoring vital signs perioperatively, there are only a few reports comparing the performance of photoplethysmography with CSI in monitoring anaesthesia depth. The aim of the present study was to clarify features of photoplethysmography in monitoring balanced general anesthesia compared with CSI. Material/Methods Forty-five patients undergoing elective operation under general anaesthesia were...
13. Litterfall and Leaf Area Index in the CONECOFOR Permanent Monitoring Plots
OpenAIRE
Cutini, Andrea
2002-01-01
Forest canopies are more sensitive and react more promptly to abiotic and biotic disturbances than other stand structural components. Monitoring crown and canopy characteristics is therefore a crucial issue for intensive and continuous monitoring programs of forest ecosystem status. These observations formed the basis for the measurement of annual litter production and leaf area index (LAI) in the Italian permanent monitoring plots (CONECOFOR program) established within the EC-UN/ECE program ...
14. Costs of detection bias in index-ased population monitoring
Directory of Open Access Journals (Sweden)
Moore, C. T.
2004-06-01
Full Text Available Managers of wildlife populations commonly rely on indirect, count-based measures of the population in making decisions regarding conservation, harvest, or control. The main appeal in the use of such counts is their low material expense compared to methods that directly measure the population. However, their correct use rests on the rarely-tested but often-assumed premise that they proportionately reflect population size, i.e., that they constitute a population index. This study investigates forest management for the endangered Red-cockaded Woodpecker (Picoides borealis and the Wood Thrush (Hylocichla mustelina at the Piedmont National Wildlife Refuge in central Georgia, U.S.A. Optimal decision policies for a joint species objective were derived for two alternative models of Wood Thrush population dynamics. Policies were simulated under scenarios of unbiasedness, consistent negative bias, and habitat-dependent negative bias in observed Wood Thrush densities. Differences in simulation outcomes between biased and unbiased detection scenarios indicated the expected loss in resource objectives (here, forest habitat and birds through decision-making based on biased population counts. Given the models and objective function used in our analysis, expected losses were as great as 11%, a degree of loss perhaps not trivial for applications such as endangered species management. Our analysis demonstrates that costs of uncertainty about the relationship between the population and its observation can be measured in units of the resource, costs which may offset apparent savings achieved by collecting uncorrected population counts.
15. Index
OpenAIRE
Editörden
2013-01-01
ed and indexed in Copernicus, Index Google Scholarship, the PSCR, DOAJ, Research Bible, Indian Open Access Journals (OAJ), Institutional Repositories (IR), Journal TOCs, J-Gate (Informatics India), Ulrich’s, ResearchGate, International Society of Universal Research in Sciences, DRJI, EyeSource
16. Index
OpenAIRE
Editörden
2014-01-01
ed and indexed in Copernicus, Index Google Scholarship, the PSCR, DOAJ, Research Bible, Indian Open Access Journals (OAJ), Institutional Repositories (IR), Journal TOCs, J-Gate (Informatics India), Ulrich’s, ResearchGate, International Society of Universal Research in Sciences, DRJI, EyeSource
17. BISPECTRAL ANALYSIS OF SCALP ELECTROENCEPHALOGRAMS: QUADRATIC PHASECOUPLING PHENOMENON IN DETECTING BRAIN TUMOR
Directory of Open Access Journals (Sweden)
V. Salai Selvam
2013-01-01
Full Text Available Since the power spectral analysis of a non-Gaussian process generated by a nonlinear mechanism e.g., EEG, does not provide much information on the underlying nonlinear dynamics due to the lack of phase information, the higher-order statistics such as the bispectra are used to better understand the underlying nonlinear dynamics e.g., the quadratic phase coupling phenomena. The quadratic phase couplings have been observed in the EEG by the researchers over a decade for many diagnostic applications such as epilepsy, sleep, mental states. This study discusses the use of bispectral analysis of the EEG recorded from the posterior region of the head of the brain tumor patient in quantifying the quadratic phase couplings to indicate the presence of the tumor. The Bicoherence Index (BCI or simply the Bicoherence (BIC has been used for the purpose. Self-couplings (around 27-52% in the [8-13] Hz (alpha band and phase couplings (around 23-42% in the [1-8] Hz (delta-theta band have been observed for the normal subjects while only self-couplings (around 0.05 to the BIC in discriminating the brain tumor case from the normal one.
18. METHOD OF MONITORING MINERALS USING REMOTE SENSING DATA BASED ON SPECTRAL INDEX
OpenAIRE
Hung, Trinh; Varvarina, E.
2013-01-01
The paper presents the results of monitoring iron oxide, clay mineral by using LANDSAT 7 ETM+ image based on spectral index in Musan area (North Korea). The results which are obtained in this study can be used to create distribution clay mineral, iron oxide map, and to serve mineral mining and exploration.
19. Drought monitoring and analysis in China based on the Integrated Surface Drought Index (ISDI)
Science.gov (United States)
Wu, Jianjun; Zhou, Lei; Mo, Xinyu; Zhou, Hongkui; Zhang, Jie; Jia, Ruijing
2015-09-01
Timely and accurate monitoring of the onset and evolution of drought in China are important to reduce losses from drought. The Integrated Surface Drought Index (ISDI) which originally established in mideast China shows a large potential for real-time regional drought monitoring. However, ISDI is still at the developmental stage, and the applicability of the index requires further examination especially for China with vast area, climatic conditions, complex topography, and land cover. Furthermore, ISDI model depends on the historical training data corresponding to the study area. ISDI application in China must be remodeled using the historical training data over China. In this paper, we remodeled ISDI over China based on previous work and evaluated its capability for near real-time drought monitoring. Using the Palmer Drought Severity Index (PDSI) as a dependent variable, ISDI integrates climate-based drought indices, satellite-based Vegetation Index (VI) and land surface temperature (LST) with other biophysical and elevation data to produce a 1-km regional drought condition map at 16-day intervals. Strong relationships were determined between the calculated ISDI and PDSI for spring, summer and autumn, and all of the correlation coefficients exceeded 0.8. The initial ISDI results demonstrated a good performance for monitoring droughts in southwestern China from 2009 to 2010, high temperatures and droughts in southern China in 2013, and floods in northeastern China in 2013. The higher spatial resolution and near real-time capability of ISDI can provide important inputs for drought management and mitigation in China.
20. An Index (PC) Aimed at Monitoring the (P)olar (C)ap for Magnetic Activity
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — PC is an index for magnetic activity in the (P)olar (C)ap. It is based on data from a single nearpole station, and aimed to monitor the polar cap magnetic activity...
1. Intelligent Monitoring System on Prediction of Building Damage Index using Artificial Neural Network
Directory of Open Access Journals (Sweden)
2012-03-01
Full Text Available An earthquake potentially destroys a tall building. The building damage can be indexed by FEMA into three categories namely Immediate Occupancy (IO, Life Safety (LS, and Collapse Prevention (CP. To determine the damage index, the building model has been simulated into structure analysis software. Acceleration data has been analyzed using non linear method in structure analysis program. The earthquake load is time history at surface, PGA=0105g. This work proposes an intelligent monitoring system utilizing Artificial Neural Network to predict the building damage index. The system also provides an alert system and notification to inform the status of the damage. Data learning is trained on ANN utilizing feed forward and back propagation algorithm. The alert system is designed to be able to activate the alarm sound, view the alert bar or text, and send notification via email to the security or management. The system is tested using sample data represented in three conditions involving IO, LS, and CP. The results show that the proposed intelligent monitoring system could provide prediction of up to 92% rate of accuracy and activate the alert. Implementation of the system in building monitoring would allow for rapid, intelligent and accurate prediction of the building damage index due to earthquake.
2. Indexed
CERN Document Server
Hagy, Jessica
2008-01-01
Jessica Hagy is a different kind of thinker. She has an astonishing talent for visualizing relationships, capturing in pictures what is difficult for most of us to express in words. At indexed.blogspot.com, she posts charts, graphs, and Venn diagrams drawn on index cards that reveal in a simple and intuitive way the large and small truths of modern life. Praised throughout the blogosphere as “brilliant,” “incredibly creative,” and “comic genius,” Jessica turns her incisive, deadpan sense of humor on everything from office politics to relationships to religion. With new material along with some of Jessica’s greatest hits, this utterly unique book will thrill readers who demand humor that makes them both laugh and think.
3. Planning and Monitoring of Urban Development: The Role of the Housing Price Index
Directory of Open Access Journals (Sweden)
Tomi Deutsch
2016-01-01
Full Text Available In this paper the real estate market in Slovenia and selected Slovenian city municipalities is analyzed with the goal of establishing whether or not it is possible to use the Housing Price Index as an indicator of urban development. The analysis shows that the real estate market in the Slovenian city municipalities has in recent decades been subject to a number of changes with a long-term effect. The analysis further proves that under certain conditions the Housing Price Index can serve as one of the indicators policy makers could use in planning and monitoring of urban development.
4. Monitoring of temperature-mediated adipose tissue phase transitions by refractive-index measurements
Science.gov (United States)
Yanina, I. Yu.; Popov, A. P.; Bykov, A. V.; Tuchin, V. V.
2014-10-01
Monitoring of temperature-mediated adipose tissue phase transitions were studied in vitro using an Abbe refractometer. The 1-2-mm thick porcine fat tissues slices were used in the experiments. The observed change in the tissue was associated with several phase transitions of lipid components of the adipose tissue. It was found that overall heating of a sample from the room to higher temperature led to more pronounced and tissue changes in refractive index if other experimental conditions were kept constant. We observed an abrupt change in the refractive index in the temperature range of 37-60 °C.
5. Monitoring Crop Yield in USA Using a Satellite-Based Climate-Variability Impact Index
Science.gov (United States)
Zhang, Ping; Anderson, Bruce; Tan, Bin; Barlow, Mathew; Myneni, Ranga
2011-01-01
A quantitative index is applied to monitor crop growth and predict agricultural yield in continental USA. The Climate-Variability Impact Index (CVII), defined as the monthly contribution to overall anomalies in growth during a given year, is derived from 1-km MODIS Leaf Area Index. The growing-season integrated CVII can provide an estimate of the fractional change in overall growth during a given year. In turn these estimates can provide fine-scale and aggregated information on yield for various crops. Trained from historical records of crop production, a statistical model is used to produce crop yield during the growing season based upon the strong positive relationship between crop yield and the CVII. By examining the model prediction as a function of time, it is possible to determine when the in-season predictive capability plateaus and which months provide the greatest predictive capacity.
6. AIR QUALITY MONITORING WITH THE LICHEN BIODIVERSITY INDEX (LBI IN THE DISTRICT OF FAENZA (ITALY
Directory of Open Access Journals (Sweden)
Manuela Cioffi
2009-07-01
Full Text Available The Lichen Biodiversity Index (LBI is a method for monitoring air pollution. This method employs lichens living on lime trees because they are sensitive to NOx and SOx, and it considers the variations in their communities. This study was performed in 16 stations located in the suburbs of Faenza city town and the result shows a more than acceptable air quality although in some stations the air was affected by the polluting effects of the vehicle traffic.
7. Monitoring of high refractive index edible oils using coated long period fiber grating sensors
Science.gov (United States)
Coelho, Luís.; Viegas, Diana; Santos, José Luís.; de Almeida, Jose Manuel M. M.
2015-05-01
Monitoring the quality of high refractive index edible oils is of great importance for the human health. Uncooked edible oils in general are healthy foodstuff, olive oil in particular, however, they are frequently used for baking and cooking. High quality edible oils are made from seeds, nuts or fruits by mechanical processes. Nevertheless, once the mechanical extraction is complete, up to 15% of the oil remains in oil pomace and in the mill wastewater, which can be extracted using organic solvents, often hexane. Optical fiber sensors based on long period fiber gratings (LPFG) have very low wavelength sensitivity when the surround refractive index is higher than the refractive index of the cladding. Titanium dioxide (TiO2) coated LPFG could lead to the realization of high sensitivity chemical sensor for the food industry. In this work LPFG coated with a TiO2 thin film were successfully used for to detect small levels of hexane diluted in edible oils and for real time monitoring the thermal deterioration of edible oils. For a TiO2 coating of 30 nm a wavelength sensitivity of 1361.7 nm/RIU (or 0.97 nm / % V/V) in the 1.4610-1.4670 refractive index range was achieved, corresponding to 0 to 12 % V/V of hexane in olive oil. A sensitivity higher than 638 nm/RIU at 225 ºC was calculated, in the 1.4670-1.4735 refractive index range with a detection limit of thermal deterioration of about 1 minute.
8. Recurrence relations of the multi-indexed orthogonal polynomials. III
Science.gov (United States)
Odake, Satoru
2016-02-01
In Paper II, we presented conjectures of the recurrence relations with constant coefficients for the multi-indexed orthogonal polynomials of Laguerre, Jacobi, Wilson, and Askey-Wilson types. In this paper we present a proof for the Laguerre and Jacobi cases. Their bispectral properties are also discussed, which gives a method to obtain the coefficients of the recurrence relations explicitly. This paper extends to the Laguerre and Jacobi cases the bispectral techniques recently introduced by Gómez-Ullate et al. [J. Approx. Theory 204, 1 (2016); e-print arXiv:1506.03651 [math.CA
9. Recurrence Relations of the Multi-Indexed Orthogonal Polynomials : III
CERN Document Server
Odake, Satoru
2015-01-01
In a previous paper, we presented conjectures of the recurrence relations with constant coefficients for the multi-indexed orthogonal polynomials of Laguerre, Jacobi, Wilson and Askey-Wilson types. In this paper we present a proof for the Laguerre and Jacobi cases. Their bispectral properties are also discussed, which give a method to obtain the coefficients of the recurrence relations explicitly.
10. Evaluation of Three MODIS-Derived Vegetation Index Time Series for Dryland Vegetation Dynamics Monitoring
Directory of Open Access Journals (Sweden)
Linlin Lu
2015-06-01
Full Text Available Understanding the spatial and temporal dynamics of vegetation is essential in drylands. In this paper, we evaluated three vegetation indices, namely the Normalized Difference Vegetation Index (NDVI, the Soil-Adjusted Vegetation Index (SAVI and the Enhanced Vegetation Index (EVI, derived from the Moderate Resolution Imaging Spectroradiometer (MODIS Surface-Reflectance Product in the Xinjiang Uygur Autonomous Region, China (XUAR, to assess index time series’ suitability for monitoring vegetation dynamics in a dryland environment. The mean annual VI and its variability were generated and analyzed from the three VI time series for the period 2001–2012 across XUAR. Two phenological metrics, start of the season (SOS and end of the season (EOS, were detected and compared for each vegetation type. The mean annual VI images showed similar spatial patterns of vegetation conditions with varying magnitudes. The EVI exhibited high uncertainties in sparsely vegetated lands and forests. The phenological metrics derived from the three VIs are consistent for most vegetation types, with SOS and EOS generated from NDVI showing the largest deviation.
11. Dynamic Drought Monitoring in Guangxi Using Revised Temperature Vegetation Dryness Index
Institute of Scientific and Technical Information of China (English)
LU Yuan; TAG Heping; WU Hua
2007-01-01
Moderate resolution imaging spectroradiometer (MODIS) data are very suitable for vast extent, long term and dynamic drought monitoring for its high temporal resolution, high spectral resolution and moderate spatial resolution. The composite Enhanced Vegetation Index (EVI) and composite land surface temperature (Ts) obtained from MODIS data MOD11A2 and MOD13A2 were used to construct the EVI-rs space. And Temperature Vegetation Dryness Index (TVDI) was calculated to evaluate the agriculture drought in Guangxi province, China in October of 2006. The results showed that the drought area in Guangxi was evidently increasing and continuously deteriorating from the middle of September to the middle of November. The TVDI, coming from the EVI-rs space, could effectively indicate the spatial distribution and temporal evolution of drought, so that it could provide a strong technical support for the forecasting agricultural drought in south China.
12. SeaDataNet network services monitoring: Definition and Implementation of Service availability index
Science.gov (United States)
Lykiardopoulos, Angelos; Mpalopoulou, Stavroula; Vavilis, Panagiotis; Pantazi, Maria; Iona, Sissy
2014-05-01
13. Bispectral methods of signal processing applications in radar, telecommunications and digital image restoration
CERN Document Server
Totsky, Alexander V; Kravchenko, Victor F
2015-01-01
By studying applications in radar, telecommunications and digital image restoration, this monograph discusses signal processing techniques based on bispectral methods. Improved robustness against different forms of noise as well as preservation of phase information render this method a valuable alternative to common power-spectrum analysis used in radar object recognition, digital wireless communications, and jitter removal in images.
14. Wearable system for non-invasive and continuous monitoring central aortic pressure curve and augmentation index.
Science.gov (United States)
Krivoshei, Andrei; Lamp, Jürgen; Min, Mart; Uuetoa, Tiina; Uuetoa, Hasso; Annus, Paul
2013-01-01
The paper presents a non-invasive method and system for a long-term and continuous monitoring of the central aortic pressure (CAP) waveform and the augmentation index (AI). The CAP curve is estimated from the measured radial electrical bio-impedance (EBI) using spectral domain transfer functions (TF), which are established on the basis of data analysis during clinical experiments. Experiments were carried out on 3 volunteers by now. During the experiment, a 0.5 mg sublingual nitroglycerin tablet was administrated to each volunteer. Both, the reconstructed CAP curve and the AI have very good correlation with the results obtained by the SphygmoCor system. But, in opposite to the traditional tonometry based CAP curve and AI estimation methods, the proposed one is more convenient to use and allows continuous and long-term personalized monitoring of the CAP curve and of the AI. PMID:23739366
15. Analysis and assessment of Shortwave Angle and Slope Index for monitoring rice phenology and hydroperiod.
Science.gov (United States)
Tornos, Lucía; Moyano, María Carmen; Huesca, Margarita; Cicuendez, Victor; Recuero, Laura; Domínguez, Jose Antonio; Palacios-Orueta, Alicia
2014-05-01
According to the United Nations, more than 50 percent of the world population depends on rice for about 80 percent of its food requirements. Besides, rice fields are important aquatic ecosystems, hosting a great variety of aquatic species. However, environmental issues such as water consumption and the emission of greenhouse gases, as well as the effects of climate change in crops, may endanger their sustainability. In this context, the determination of rice hydroperiod and phenology is necessary for rice monitoring and impact management, and is expected to become more relevant in the near future. The present study has explored the potential of Shortwave Angle Slope Index (SASI), based on the spectral data contained in Moderate Resolution Imaging Spectroradiometer, to monitoring rice paddy fields under different water management practices. SASI is a spectral shape index (SSI), based on the angle formed in SWIR1 vertex with NIR and SWIR2 in the spectrum, and the slope of the line linking NIR and SWIR2 vertices. This index was developed to distinguish between dry soil, wet soil, dry vegetation and green vegetation. It takes large, positive values for dry soil and large, negative values for green vegetation. Two case studies in Spain, the Ebro Delta and Orellana are presented. The behaviour of the index in each zone for the period 2001-2012 has been evaluated to characterize the response of SASI index to phenological and flooding events in rice. The average values and standard deviation of the index for the period 2001-2012 were calculated to identify the significant points of SASI in coincidence with phenological and flooding field data. An algorithm for the detection of significant points was also applied to determine phenological metrics, based on the information obtained. SASI presented similar values for both zones during the rice growing period. Differences arose during the non-growing period when the Delta was flooded for environmental reasons (i
16. Single-mode D-shaped optical fiber sensor for the refractive index monitoring of liquid
Science.gov (United States)
2016-04-01
A new fabrication method is introduced for the production of D-shaped optical fiber. A mechanical end and edge polishing system with aluminum oxide polishing film is utilized to perform sequential polishing on one side (lengthwise) of single-mode optical fiber in order to obtain a D-shaped cross section. Adjusting specific mechanical parameters allows for control of the volume of the D-shaped zone, while the fiber surface smoothness is governed by selection of polishing film grit size. To meet the accuracy and repeatability requirements, optical power loss is monitored during the entire polishing process in situ and in real time. This proposed technique possesses advantages of rapidity, safety, simplicity, repeatability and stability with high precision in comparison with contemporary methods for production. Sensor performance tests on the fiber reveal a linear response with linearity up to R2 = 0.984 for surrounding refractive index in the range of 1.320-1.342 refractive index, which corresponds to different concentrations of the glucose solution test environment. The produced D-shaped optical fiber has potential sensing and monitoring applications in chemical, environmental, biological and biochemical fields.
17. [New index for soil moisture monitoring based on deltaT(s)-albedo spectral information].
Science.gov (United States)
Yao, Yun-Jun; Qin, Qi-Ming; Zhao, Shao-Hua; Shen, Xin-Yi; Sui, Xin-Xin
2011-06-01
Monitoring soil moisture by remote sensing has been an important problem for both agricultural drought monitoring and water resources management. In the present paper, we acquire the land surface temperature difference (deltaT(s)) and broadband albedo using MODIS Terra reflectance and land surface temperature products to construct the deltaT(s)-albedo spectral feature space. According to the soil moisture variation in spectral feature space, we put forward a simple and practical temperature difference albedo drought index (TDADI) and validate it using ground-measured 0-10 cm averaged soil moisture of Ningxia plain The results show that the coefficient of determination (R2) of both them varies from 0.36 to 0.52, and TDADI has higher accuracy than temperature albedo drought index (TADI) for soil moisture retrieval. The good agreement of TDADI, Albedo/LST, LST/ NDVI and TVDI for analyzing the trends of soil moisture change supports the reliability of TDADI. However, TDADI has been designed only at Ningxia plain and still needs further validation in other regions. PMID:21847933
18. Litterfall and Leaf Area Index in the CONECOFOR Permanent Monitoring Plots
Directory of Open Access Journals (Sweden)
Andrea CUTINI
2002-09-01
Full Text Available Forest canopies are more sensitive and react more promptly to abiotic and biotic disturbances than other stand structural components. Monitoring crown and canopy characteristics is therefore a crucial issue for intensive and continuous monitoring programs of forest ecosystem status. These observations formed the basis for the measurement of annual litter production and leaf area index (LAI in the Italian permanent monitoring plots (CONECOFOR program established within the EC-UN/ECE program "Intensive Monitoring (Level II of Forest Ecosystems". Preliminary results after three years of observation are presented. The low value of within plot mean relative standard deviation (20.8 ± 1.9% of litter production, which in any case never exceeded 30%, accounted for the good sampling error and accuracy of the chosen method, which seems to be accurate enough to detect changes in litter production through the years. The higher inconsistency of the amount of woody and fruits fractions over the years demonstrated the greater reliability of leaf fraction or, on the other hand, of LAI compared to total litter. Mean values of annual leaf-litter and total litter production and LAI were rather high in comparison with data reported in literature for similar stands, and reflected both a medium-high productivity and a juvenile phase in the development of the selected stands on average. Focusing on changes in litter production through the years, statistical analysis on a sub-sample of plots showed the existence of significant differences both in leaf litter and total litter production. These findings seem to attribute to the "year" factor a driving role in determining changes in litter production and LAI. Temporal intermittence in data collection, together with the shortness of the monitoring period, make it difficult to speculate or arrive at definitive conclusions on changes in litter production due to time-dependent factors. The importance of having a complete
19. Relative sensitivity of Normalized Difference Vegetation Index (NDVI) and Microwave Polarization Difference Index (MPDI) for vegetation and desertification monitoring
Science.gov (United States)
1988-01-01
A simple equation relating the Microwave Polarization Difference Index (MPDI) and the Normalized Difference Vegetation Index (NDVI) is proposed which represents well data obtained from Nimbus 7/SMMR at 37 GHz and NOAA/AVHRR Channels 1 and 2. It is found that there is a limit which is characteristic of a particular type of cover for which both indices are equally sensitive to the variation of vegetation, and below which MPDI is more efficient than NDVI. The results provide insight into the relationship between water content and chlorophyll absorption at pixel size scales.
20. Scale effects of leaf area index inversion based on environmental and disaster monitoring satellite data
Institute of Scientific and Technical Information of China (English)
2010-01-01
The spatial distribution of sub-pixel components has an impact on retrieval accuracy,and should be accounted for when inverting a three-dimensional adiative transfer model to retrieve leaf area index(LAI).To investigate this effect,we constructed three realistic scenarios with the same LAI values and other properties,except that the simulated plants had different distributions.We implemented the radiosity method to subsequently produce synthetic bidirectional reflectance factor(BRF) datasets based upon these simulated scenes.The inversion was conducted using these data,which showed that spatial distribution affects retrieval accuracy.The inversion was also conducted for LAI based on charge-coupled device(CCD) data from the Environment and Disaster Monitor Satellite(HJ-1),which depicted both forest and drought-resistant crop land cover.This showed that heterogeneity in coarse-resolution remote sensing data is the main error source in LAI inversion.The spatial distribution of global fractal dimension index,which can be used to describe the area of sub-pixel components and their spatial distribution modes,shows good consistency with the coarse resolution LAI inversion error.
1. A hybrid algorithm for reengineering the refractive index profile of inhomogeneous coatings from optical in-situ broadband monitoring data
Institute of Scientific and Technical Information of China (English)
S.Wilbrandt; O.Stenzel; D.G(a¨)bler; N.Kaiser
2005-01-01
Reengineering the refractive index profile of inhomogeneous coatings is a troublesome task. Multiplicity of solutions may significantly reduced by providing additional information. For this reason an in-situ broadband monitoring system was developed to measure the transmittance of the growing film directly at the rotating substrate. For characterization of these coatings, a new model was developed, which significantly reduces the number of parameters. The refractive index profile may be described by a proper number of equally spaced volume fraction values using the Bruggeman effective media approach. A good initial approximation of the refractive index profile can be generated based on deposition rates for both materials recorded with quartz crystal monitor during manufacturing. During the optimization process, a second order minimization algorithm was used to vary the refractive index profile of the whole coating and film thickness of the intermediate stages. Finally, a significantly improved accuracy of the modelled transmittance was achieved.
2. Evaluation of a Remotely Sensed Evaporative Stress Index for Monitoring Patterns of Anomalous Water Use
Science.gov (United States)
Anderson, M. C.; Hain, C.; Otkin, J.; Zhan, X.
2012-12-01
Drought assessment is a complex endeavor, requiring monitoring of deficiencies in multiple components of the hydrologic budget. Precipitation anomalies reflect variability in water supply to the land surface, while soil moisture (SM), ground and surface water anomalies reflect deficiencies in moisture storage. In contrast, evapotranspiration (ET) anomalies provide unique yet complementary information, reflecting variations in actual water use by crops and direct evaporation from the soil. For example, precipitation- and ET-based anomalies may differ significantly in regions of intensive irrigation, shallow water table, or deep rooting depth - areas where plants may be more resilient to soil moisture deficiencies inferred from rainfall patterns. In addition, an ET-based index can better capture impacts of hot, windy conditions leading to "flash droughts", where anomalously high water use precipitates rapid decay in soil moisture and crop condition. Here we describe a remotely sensed Evaporative Stress Index (ESI) based on anomalies in actual-to-reference ET ratio, and compare with patterns in precipitation-based drought indicators. Actual ET is derived from thermal remote sensing, using the morning land-surface temperature (LST) rise observed with geostationary satellites. In comparison with vegetation indices, LST is a fast-response variable, with the potential for providing early warning of crop stress reflected in increasing canopy temperatures. Spatiotemporal patterns in ESI reasonably match those in precipitation-based indices (such as SPI and modeled SM) and patterns in the U.S. Drought Monitor. However, because ESI does not use precipitation as an input, it provides an independent assessment of evolving drought conditions, and is more portable to data-sparse parts of the world lacking dense rain-gauge and Doppler radar networks. Integrating LST information from polar orbiting systems, the ESI has unique potential for sensing moisture stress at field scale
3. Monitored anesthesia care (MAC sedation: clinical utility of fospropofol
Directory of Open Access Journals (Sweden)
Eric A Harris
2009-12-01
Full Text Available Eric A Harris, David A Lubarsky, Keith A CandiottiDepartment of Anesthesiology, Perioperative Management, and Pain Medicine, University of Miami/Miller School of MedicineAbstract: Fospropofol, a phosphorylated prodrug version of the popular induction agent propofol, is hydrolyzed in vivo to release active propofol, formaldehyde, and phosphate. Pharmacodynamic studies show fospropofol provides clinically useful sedation and EEG/bispectral index suppression while causing significantly less respiratory depression than propofol. Pain at the injection site, a common complaint with propofol, was not reported with fospropofol; the major patient complaint was transitory perianal itching during the drug’s administration. Although many clinicians believe fospropofol can safely be given by a registered nurse, the FDA mandated that fospropofol, like propofol, must be used only in the presence of a trained anesthesia provider.Keywords: fospropofol, propofol, monitored anesthesia care
4. Effect of Body Mass Index on Intrafraction Prostate Displacement Monitored by Real-Time Electromagnetic Tracking
International Nuclear Information System (INIS)
Purpose: To evaluate, using real-time monitoring of implanted radiofrequency transponders, the intrafraction prostate displacement of patients as a function of body mass index (BMI). Methods and Materials: The motions of Beacon radiofrequency transponders (Calypso Medical Technologies, Seattle, WA) implanted in the prostate glands of 66 men were monitored throughout the course of intensity modulated radiation therapy. Data were acquired at 10 Hz from setup to the end of treatment, but only the 1.7 million data points with a “beam on” tag were used in the analysis. There were 21 obese patients, with BMI ≥30 and 45 nonobese patients in the study. Results: Mean displacements were least in the left-right lateral direction (0.56 ± 0.24 mm) and approximately twice that magnitude in the superior-inferior and anterior-posterior directions. The net vector displacement was larger still, 1.95 ± 0.47 mm. Stratified by BMI cohort, the mean displacements per patient in the 3 Cartesian axes as well as the net vector for patients with BMI ≥30 were slightly less (<0.2 mm) but not significantly different than the corresponding values for patients with lower BMIs. As a surrogate for the magnitude of oscillatory noise, the standard deviation for displacements in all measured planes showed no significant differences in the prostate positional variability between the lower and higher BMI groups. Histograms of prostate displacements showed a lower frequency of large displacements in obese patients, and there were no significant differences in short-term and long-term velocity distributions. Conclusions: After patients were positioned accurately using implanted radiofrequency transponders, the intrafractional displacements in the lateral, superior-inferior, and anterior-posterior directions as well as the net vector displacements were smaller, but not significantly so, for obese men than for those with lower BMI.
5. Monitoring the Sequential Cropping Index of Arable Land in Zhejiang Province of China Using MODIS-NDVI
Institute of Scientific and Technical Information of China (English)
PENG Dai-liang; HUANG Jing-feng; JIN Hui-min
2007-01-01
The sequential cropping index of arable land is important agricultural information. The aim of this article is to monitor and analyze the parameter, and offer reference for agricultural production. The cropping index of arable land in Zhejiang Province, China from 2001 to 2004 was calculated using the second order difference based MODIS (moderate resolution imagine spectroradimeter) vegetation data from NASA (National Aeronautic and Space Administration) in America and the land use map with a scale of 1:25 000. It was found that the peak of the time series of the NDVI curve indicated that the ground biomass of crops reached the maximum, and fluctuated with the crops growing processes such as sowing,seeding, heading, ripeness, and harvesting within one year. Thus, the sequential cropping index was defined as the number of peaks of the time series of the NDVI curve. The sequential cropping index of all cities in Zhejiang Province,China was worked out. It is seen from the spatial distribution that the cropping index in the southwest Zhejiang Province is larger than that in the northeast. As for the temporal distribution, the sequential cropping index decreased from 2001 to 2003, whereas it increased slightly from 2003 to 2004. However, the index of arable land was relatively low, as far as the geographic position and climatic resource were concerned, and the potential of the sequential cropping index was great.
6. Indexed bibliography on tritium: its sources and projections, behavior, measurement and monitoring techniques, health physics aspects, and waste management
International Nuclear Information System (INIS)
References are presented to the world literature on sources of tritium in the environment, the migration of tritium in the environment and uptake by biological materials, monitoring methods, health aspects, and radioactive waste management. Subject, author, and permuted title indexes are included. (U.S.)
7. Lung clearance index for monitoring early lung disease in alpha-1-antitrypsin deficiency.
Science.gov (United States)
Fuchs, Susanne I; Schwerk, Nicolaus; Pittschieler, Klaus; Ahrens, Frank; Baden, Winfried; Bals, Robert; Fähndrich, Sebastian; Gleiber, Wolfgang; Griese, Matthias; Hülskamp, Georg; Köhnlein, Thomas; Reckling, Ludmilla; Rietschel, Ernst; Staab, Doris; Gappa, Monika
2016-07-01
Patients with alpha-1-antitrypsin deficiency (AATD) and a PI-ZZ genotype are at high risk to develop severe emphysema during adulthood. However, little is known about early stages of emphysema and disease manifestation in other PI-types. Spirometry is commonly used for monitoring although early manifestation of emphysema is suspected within the peripheral airways that are not accessible by forced expiratory manoeuvres. We hypothesized that the Lung Clearance Index (LCI) derived from multiple breath nitrogen-washout (N2-washout) is useful to bridge this diagnostic gap. Patients from age 4 years onward and different PI-types performed N2-washout and spirometry. Results were compared to controls. 193 patients (4-79 years, 75% PI-ZZ) and 33 controls (8-60 years) were included. Mean (SD) LCI in patients was 9.1 (3.1) and 6.3 (0.6) in controls (p ≤ 0.001). 47% of adult patients with other than PI-ZZ genotypes and 39% of all patients with normal spirometry had abnormal LCIs. The LCI measured by N2-washout discriminates between patients with AATD and controls, reflects AATD related lung disease in all stages and appears to identify early peripheral lung changes in younger age than spirometry. We conclude that a normal spirometry does not exclude presence of AATD related lung disease even in genotypes other than PI-ZZ. PMID:27296827
8. DICOM index tracker enterprise: advanced system for enterprise-wide quality assurance and patient safety monitoring
Science.gov (United States)
Zhang, Min; Pavlicek, William; Panda, Anshuman; Langer, Steve G.; Morin, Richard; Fetterly, Kenneth A.; Paden, Robert; Hanson, James; Wu, Lin-Wei; Wu, Teresa
2015-03-01
DICOM Index Tracker (DIT) is an integrated platform to harvest rich information available from Digital Imaging and Communications in Medicine (DICOM) to improve quality assurance in radiology practices. It is designed to capture and maintain longitudinal patient-specific exam indices of interests for all diagnostic and procedural uses of imaging modalities. Thus, it effectively serves as a quality assurance and patient safety monitoring tool. The foundation of DIT is an intelligent database system which stores the information accepted and parsed via a DICOM receiver and parser. The database system enables the basic dosimetry analysis. The success of DIT implementation at Mayo Clinic Arizona calls for the DIT deployment at the enterprise level which requires significant improvements. First, for geographically distributed multi-site implementation, the first bottleneck is the communication (network) delay; the second is the scalability of the DICOM parser to handle the large volume of exams from different sites. To address this issue, DICOM receiver and parser are separated and decentralized by site. To facilitate the enterprise wide Quality Assurance (QA), a notable challenge is the great diversities of manufacturers, modalities and software versions, as the solution DIT Enterprise provides the standardization tool for device naming, protocol naming, physician naming across sites. Thirdly, advanced analytic engines are implemented online which support the proactive QA in DIT Enterprise.
9. Enhancing Medium Spatial Resolution Forest Cover Change Monitoring with a MODIS-Based Disturbance Index
Science.gov (United States)
Kim, D.; Huang, C.; Sexton, J. O.; Channan, S.; Song, D.; Song, X.; Townshend, J. R.
2012-12-01
1. INTRODUCTION Since the opening of the United States Geological Survey's (USGS) Landsat data archive, demands and possibility to document land surface change using Landsat data in large area is increasing. Especially, a global scale monitoring of forest change is required to serve as a baseline for any efforts to cut the carbon emission from deforestation. Several algorithms are being developed for the monitoring of forest change in large area using medium spatial resolution data. Due to its large data volume and difficulties in collecting retrospective ground reference data, automated approaches such as Training Data Automation - Support Vector Machine (TDA-SVM) are developed. To enhance the quality of the results from such methods, this study proposes a method to augment training data using the disturbance information from MODIS and Land Surface Temperature time series. 2. METHOD TDA-SVM is an algorithm to automate whole procedure of forest cover change monitoring using Landsat data. The TDA procedure automatically generates training data from a pair of satellite image. Derived training data is used to produce forest cover change maps. However, current TDA-SVM makes commission errors in some cases. These errors are due to the lack of training samples at the spectral boundary between classes. To add more training samples at spectral boundary, Disturbance Index (DI) is used. This approach is based on strong correlation between vegetation amount and surface temperature. First, Landsat pixels at a spectral boundary between classes are identified by TDA. Second, Disturbance Indices for each 1 km MODIS pixels are calculated to identify the area of which DI is lower than the natural variance. Boundary pixels aggregated into 1km are compared to the DI of spatially corresponding MODIS pixel. Finally, selected boundary pixels of which corresponding DI is lower than natural variability are updated as persistent non-forest. These updated pixels are added as additional
10. Monitoring changes in economy-wide energy efficiency: From energy-GDP ratio to composite efficiency index
International Nuclear Information System (INIS)
Since the 1973 world oil crisis, monitoring trends in energy efficiency at the economy-wide level has been an important component of energy strategy in many countries. To support this effort, various energy efficiency-related indicators have been developed. We examine some classical indicators which are often found in national and international energy studies in the 1970s and 1980s. We then describe the recent developments in using the index decomposition analysis to give an economy-wide composite energy efficiency index based on a bottom-up approach. This composite index is superior to the classical indicators as an economy-wide energy efficiency measure and has lately been adopted by a growing number of countries for national energy efficiency trend monitoring
11. Structure of forest ecosystems and leaf area index of wood plants -results of monitoring over the years 1991-1994
International Nuclear Information System (INIS)
Monitored characteristics and their dynamics over the last four vegetation seasons reveal the following conclusions: 1) Changes of monitored parameters (e.g. the structure of tree and shrub layer, the leaf area index) are slow, drab and insignificant at the permanent monitoring representing a major part of forest ecosystems of the area affected by the Hydroelectric power structures Gabcikovo. Despite the absence of floods, the ground water level is at a sufficient height to contact rhisosphere of wood plants and the recorded changes are in accord with growth regularities. 2) An increase of the ground water level in the upper part of the monitored territory and a partial renaturation of hydropedological conditions led to an improvement of production-ecological parameters of the area. Changes of its structure are of positive tendency, the leaf area index is stabilised at high values and somewhere even increased (in 1994 being by 70-80% higher than in 1991). 3) Localities with a permanent decrease of the ground water level (band along the old river-bed of the Danube, a dry triangle among the old river-bed of the Danube, the inlet canal and the river arm supplied by the intake structure at Dobrohost and other places) were afflicted by negative changes, locally indicating destruction of tree and shrub layers, with the leaf area index significantly reduced by 20-30%. (author). 1 tab., 5 refs
12. Bispectral experimental estimation of the nonlinear energy transfer in two-dimensional plasma turbulence
DEFF Research Database (Denmark)
Manz, P.; Ramisch, M.; Stroth, U.;
2008-01-01
-wave turbulence. The density fluctuations, which at the realistic collisionality are advected as a passive scalar with the vorticity, show power transfer from large to small scales, while the spectral power in potential fluctuations, which represents the energy, is transferred as an inverse cascade to larger......Experimental density and potential fluctuation data from a 2D probe array have been analysed to study the turbulent cascade in a toroidally confined magnetized plasma. The bispectral analysis technique used is from Ritz et al ( 1989 Phys. Fluids B 1 153) and Kim et al ( 1996 Phys. Plasmas 3 3998...
13. The Vegetation Drought Response Index (VegDRI): A new integrated approach for monitoring drought stress in vegetation
Science.gov (United States)
Brown, J.F.; Wardlow, B.D.; Tadesse, T.; Hayes, M.J.; Reed, B.C.
2008-01-01
The development of new tools that provide timely, detailed-spatial-resolution drought information is essential for improving drought preparedness and response. This paper presents a new method for monitoring drought-induced vegetation stress called the Vegetation Drought Response Index (VegDRI). VegDRI integrates traditional climate-based drought indicators and satellite-derived vegetation index metrics with other biophysical information to produce a I km map of drought conditions that can be produced in near-real time. The initial VegDRI map results for a 2002 case study conducted across seven states in the north-central United States illustrates the utility of VegDRI for improved large-area drought monitoring. Copyright ?? 2008 by Bellwether Publishing, Ltd. All rights reserved.
14. Monitoring effects of simulated disturbance at INDEX site: Current status and future activities
Digital Repository Service at National Institute of Oceanography (India)
Sharma, R.; Nath, B.N.; Valsangkar, A.B.; Khadge, N.H.; Parthiban, G.; Sankar, S.J.; Ansari, Z.A.; Ingole, B.S.; Raghukumar, C.; LokaBharathi, P.A.; Matondkar, S.G.P.; RameshBabu, V.; Murty, V.S.N.; Babu, M.T.; Sardar, A.
During the Indian Deep-Sea Environment Experiment (INDEX), greater than 6000 cu.m of sediment was resuspended 5 m above seafloor. Data collected from deep-towed photography, sediment traps, sediment coring and CTD operations before and after...
15. Planning and Monitoring of Urban Development: The Role of the Housing Price Index
OpenAIRE
Tomi Deutsch
2016-01-01
In this paper the real estate market in Slovenia and selected Slovenian city municipalities is analyzed with the goal of establishing whether or not it is possible to use the Housing Price Index as an indicator of urban development. The analysis shows that the real estate market in the Slovenian city municipalities has in recent decades been subject to a number of changes with a long-term effect. The analysis further proves that under certain conditions the Housing Price Index can serve as on...
16. EPA Office of Water (OW): STORET Water Quality Monitoring Stations NHDPlus Indexed Dataset
Data.gov (United States)
U.S. Environmental Protection Agency — Storage and Retrieval for Water Quality Data (STORET and the Water Quality Exchange, WQX) defines the methods and the data systems by which EPA compiles monitoring...
17. Monitoring the vegetation start of season (SOS) across the island of Ireland using the MERIS global vegetation index
OpenAIRE
O'Connor, Brian
2011-01-01
The aim of this study was to develop a methodology, based on satellite remote sensing, to estimate the vegetation Start of Season (SOS) across the whole island of Ireland on an annual basis. This growing body of research is known as Land Surface Phenology (LSP) monitoring. The SOS was estimated for each year from a 7-year time series of 10-day composited, 1.2 km reduced resolution MERIS Global Vegetation Index (MGVI) data from 2003 to 2009, using the time series analysis software, TIMESAT. Th...
18. Interference method for monitoring the refractive index and the thickness of transparent films during deposition
Science.gov (United States)
Alius, H.; Schmidt, R.
1990-04-01
An interferometric method is described for simultaneous measurement of the refractive index and the thickness of transparent isotropic films during the deposition process. Two laser beams are focused impinging at two different angles onto the film. The intensity of the beams reflected from the growing film shows minima and maxima, which are counted and evaluated to determine the refractive index n and the thickness d of the film in the range of some 100 nm up to several micrometers using 633-nm laser light. n and d can be determined within an accuracy better than 1%, if the thickness is larger than three times the vacuum wavelength of the laser. The measurements are well in accordance with calculations of the intensity modulation. The method can easily be extended to multilayer systems.
19. Use of crop water stress index for monitoring water stress in some sinanthropic plant species
OpenAIRE
Marinela Roxana ROŞESCU; Emil CHIŢU
2010-01-01
The water stress indicator (crop water stress index, CWSI) is a measure of the transpiration rate of a plant, influenced by the leaf and air temperature difference from the plant’s vicinity and the air pressure deficit of the water vapors from the atmosphere. The experiments were realized in July-August 2008 and 2009 for six species in the cities Pitesti, Mioveni and Maracineni: Cichorium intybus L., Conyza canadensis (L.) Cronq., Erigeron annuus L. (Pers.), Lactuca serriola Torn., Polygonum ...
20. 40 CFR Table 4 to Subpart G of... - Process Vents-Monitoring, Recordkeeping, and Reporting Requirements For Maintaining a TRE Index...
Science.gov (United States)
2010-07-01
..., and Reporting Requirements For Maintaining a TRE Index Value >1.0 and. â¤4.0 4 Table 4 to Subpart G of... TRE Index Value >1.0 and. ≤4.0 Final recovery device Parameters to be monitored a Recordkeeping and... Process Vents, Storage Vessels, Transfer Operations, and Wastewater Pt. 63, Subpt. G, Table 4 Table 4...
1. Neutronic analysis of the bi-spectral moderator such as that proposed for ESS
Energy Technology Data Exchange (ETDEWEB)
Magán, M., E-mail: [email protected] [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear – UPM, ETS Ingenieros Industriales, C José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Sordo, F. [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear – UPM, ETS Ingenieros Industriales, C José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Zanini, L. [European Spallation Source ESS AB, Box 176, 22100 Lund (Sweden); Terrón, S.; Ghiglino, A.; Martínez, F.; Vicente, J.P. de; Vivanco, R. [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear – UPM, ETS Ingenieros Industriales, C José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Perlado, J.M. [Instituto de Fusión Nuclear – UPM, ETS Ingenieros Industriales, C José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Bermejo, F.J. [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Estructura de la Materia, IEM-CSIC, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid (Spain); Mezei, F. [European Spallation Source ESS AB, Box 176, 22100 Lund (Sweden); Muhrer, G. [Lujan Neutron Scattering Center, LANSCE Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2013-11-21
This paper reports on design studies concerning a moderator concept which aims to maximize the time averaged flux. The idea is to provide neutron spectra showing two clear maxima, with peaks at (∼1Å) and (∼2.5Å) arising from leakage from both cryogenic and thermal moderators. Such a concept known as a bi-spectral moderator (Mezei, 2006 [1]) while proven on a reactor source has only been examined for the ESS 2003 proposal. Filges et al. (2003 [2]), which featured a different design than the current ESS. This paper thus reports on a baseline design for such a moderator concept and shows that it can provide substantial gains in count rates for those applications not requiring high resolution in time-of-flight.
2. Human Daily Activities Indexing in Videos from Wearable Cameras for Monitoring of Patients with Dementia Diseases
CERN Document Server
Karaman, Svebor; Mégret, Rémi; Dovgalecs, Vladislavs; Dartigues, Jean-François; Gaëstel, Yann
2010-01-01
Our research focuses on analysing human activities according to a known behaviorist scenario, in case of noisy and high dimensional collected data. The data come from the monitoring of patients with dementia diseases by wearable cameras. We define a structural model of video recordings based on a Hidden Markov Model. New spatio-temporal features, color features and localization features are proposed as observations. First results in recognition of activities are promising.
3. Monitoring leaf area index at watershed level through NDVI from Landsat-7/ETM+ data
Directory of Open Access Journals (Sweden)
Xavier Alexandre Cândido
2004-01-01
Full Text Available Leaf area index (LAI is an important parameter of the vegetation canopy, and is used, for instance, to estimate evapotranspiration, an important component of the hydrological cycle. This work analyzed the relationship between LAI, measured in field, and NDVI from four dates (derived from Landsat-7/ETM+ data, and with such vegetation index, to generate and analyze LAI maps of the study area for the diverse dates. LAI data were collected monthly in the field with LAI-2000 equipment in stands of sugar cane, pasture, corn, eucalypt, and riparian forest. The relationships between LAI and NDVI were adjusted by a potential model; 57% to 72% of the NDVI variance were explained by the LAI. LAI maps generated by empirical relationships between LAI and NDVI showed reasonable precision (standard error of LAI estimate ranged from 0.42 to 0.87 m² m-2. The mean LAI value of each monthly LAI map was shown to be related to the total precipitation in the three previous months.
4. Autoregulation monitoring and outcome prediction in neurocritical care patients: Does one index fit all?
Science.gov (United States)
Schmidt, Bernhard; Reinhard, Matthias; Lezaic, Vesna; McLeod, Damian D; Weinhold, Marco; Mattes, Heinz; Klingelhöfer, Jürgen
2016-06-01
Indexes PRx and Mx have been formerly introduced to assess cerebral autoregulation and have been shown to be associated with 3-month clinical outcome. In a mixed cohort of neurocritical care patients, we retrospectively investigated the impact of selected clinical characteristics on this association. Forty-one patients (18-77 years) with severe traumatic (TBI, N = 20) and non-traumatic (N = 21) brain injuries were studied. Cerebral blood flow velocity, arterial blood pressure and intracranial pressure were repeatedly recorded during 1-h periods. Calculated PRx and Mx were correlated with 3-month clinical outcome score of modified Rankin Scale (mRS) in different subgroups with specific clinical characteristics. Both PRx and Mx correlated significantly with outcome (PRx: r = 0.38, p mRS in patients with heart failure (N = 17; r = 0.69, p mRS in TBI patients (r = 0.63, p mRS in diabetes patients (N = 15), PRx failed in hypocapnic patients (N = 26). Both PRx and Mx were significantly associated with 3-month clinical outcome, even in patients with hemicraniectomy. PRx was more appropriate for TBI patients, while Mx was better suited for non-traumatic patients and patients with heart failure. Prognostic values of indexes were affected by diabetes (both Mx and PRx) and hypocapnia (PRx only). PMID:26085437
5. [Comparison of biotic index used in monitoring of 2 lotic systems in north-western Argentina].
Science.gov (United States)
Salusso, María M; Moraña, Liliana B
2002-03-01
Two lotic bodies located in a subtropical semi-arid region in north-western Argentina were studied: the Arias-Arenales and the Rosario rivers. Both rivers are located in Salta Province, and belong to the high basin of river Juramento, connected to the river Río de la Plata and the Atlantic Ocean. The study was conducted between March 1997 and March 1998. The region is known by its sustained economic development and one of the highest population growth rates in the country (4% per year). The objective of this work was the assessment of organic pollution spatial gradients in both rivers, as a function of the hydrological regime (a long period of drought from May to October and floodings the rest of the year). Three groups of biotic indices were applied to characterize the level of organic pollution and were based on planktonic microalgae to evaluate water quality. The relative performance of these indices was then compared for use to biomonitoring programs. The diversity indices: Shannon-Weaver and Whilm-Dorris were not highly sensible to detect moderate pollution. The saprobity indices (Pantle and Buck and Diatom Assemblage Index of Watanabe et al.), were useful to detect intermediate levels of organic load, but their sensitivity dropped at high pollution levels. The second index precisely discriminated the most deteriorated part of river Rosario, with values between 0.3-0.7 (extreme poli-saprobity). Raw sewage discharges along the most polluted sector of river Arias-Arenales were assigned a value between 10 and 11 in both periods of the hydrological regime. Both saprobity indices consider the same indicator pollution value of species. The first one is based on the relative abundance of the species while the second one is calculated with the species relative frequency. The second index is better than the first one in considering non-dominant species that were constant in each particular environmental condition. The principal component analysis allowed a
6. Use of crop water stress index for monitoring water stress in some sinanthropic plant species
Directory of Open Access Journals (Sweden)
Marinela Roxana ROŞESCU
2010-11-01
Full Text Available The water stress indicator (crop water stress index, CWSI is a measure of the transpiration rate of a plant, influenced by the leaf and air temperature difference from the plant’s vicinity and the air pressure deficit of the water vapors from the atmosphere. The experiments were realized in July-August 2008 and 2009 for six species in the cities Pitesti, Mioveni and Maracineni: Cichorium intybus L., Conyza canadensis (L. Cronq., Erigeron annuus L. (Pers., Lactuca serriola Torn., Polygonum aviculare L. and Echinochloa crus-galli (L. Beauv. For those species we calculated the CWSI to estimate the water stress on the selected plants in the urban environment conditions. The analyzed species were exposed to a less accentuated water stress while vegetating in the soil and to a more intense one they were grown in the asphalt cracks. Cichorium intybus had the smallest CWSI value (0.26 while Lactuca serriola the highest one (0.44.
7. Satellite-based forest monitoring: spatial and temporal forecast of growing index and short-wave infrared band.
Science.gov (United States)
Bayr, Caroline; Gallaun, Heinz; Kleb, Ulrike; Kornberger, Birgit; Steinegger, Martin; Winter, Martin
2016-01-01
For detecting anomalies or interventions in the field of forest monitoring we propose an approach based on the spatial and temporal forecast of satellite time series data. For each pixel of the satellite image three different types of forecasts are provided, namely spatial, temporal and combined spatio-temporal forecast. Spatial forecast means that a clustering algorithm is used to group the time series data based on the features normalised difference vegetation index (NDVI) and the short-wave infrared band (SWIR). For estimation of the typical temporal trajectory of the NDVI and SWIR during the vegetation period of each spatial cluster, we apply several methods of functional data analysis including functional principal component analysis, and a novel form of random regression forests with online learning (streaming) capability. The temporal forecast is carried out by means of functional time series analysis and an autoregressive integrated moving average model. The combination of the temporal forecasts, which is based on the past of the considered pixel, and spatial forecasts, which is based on highly correlated pixels within one cluster and their past, is performed by functional data analysis, and a variant of random regression forests adapted to online learning capabilities. For evaluation of the methods, the approaches are applied to a study area in Germany for monitoring forest damages caused by wind-storm, and to a study area in Spain for monitoring forest fires. PMID:27087034
8. A modified index for monitoring of radiation protection programmes with special reference to Nuclear Medicine Institute
International Nuclear Information System (INIS)
In India, the Institute of Nuclear Medicine and Allied Sciences was established with the main objective of developing radioisotopic methodologies for diagnosis, therapy, biomedical research and training. The steady progress in India's atomic energy program gave impetus to rapid growth in the application of nuclear medicine techniques at the Institute and now it is one of the largest users of unsealed radiation sources in the country. Right from the beginning adequate attention has been devoted to the radiation safety of the staff and personnel management techniques have been successfully employed to assess performance of the radiation protection staff. A significant positive correlation (p 0.02) between performance and job satisfaction of radiation protection personnel of the Institute has been demonstrated. Efforts are also directed to evolve a parameter that may throw light on the effectiveness of radiation protection staff and subsequently that may be helpful to monitor the radiation protection program of other establishments
9. Monitoring responses of Mason Pine to acid rain in China based on remote sensing vegetation index
International Nuclear Information System (INIS)
Since the 1970s, acid rain has remained in the public spotlight in both Europe and the United States and recently has emerged as an important problem in other regions such as Southeast Asia. To reveal responses of Masson Pine to acid rain during a long time series in central China, we used the interpolation dataset of acid rain and the Global Inventory Modeling and Mapping Studies (GIMMS) normalized difference vegetation index (NDVI) data to derive the monthly pH and NDVI trajectories based on acidity gradients from 1992 to 2006. Then we analyzed inter-annual and seasonal variation of vegetation growth by improved sinusoidal fitting and regression analysis. In the environment of strong acidity and moderate acidity, the growth of Masson Pine was inhibited during the study period, while the slight acidity promoted growth of Masson Pine to some extent. For the multi-year monthly changing trend of NDVI, late spring to mid autumn, the NDVI showed a decreasing trend, especially in June, while from late autumn to the following spring, the NDVI showed a rising tendency, specifically in December and March
10. Monitoring crop leaf area index time variation from higher resolution remotely sensed data
International Nuclear Information System (INIS)
The leaf area index (LAI) is significant for research on global climate change and ecological environment. China HJ-1 satellite has a revisit cycle of four days, providing CCD data (HJ-1 CCD) with a resolution of 30 m. However, the HJ-1 CCD is incapable of obtaining observations at multiple angles. This is problematic because single angle observations provide insufficient data for determining the LAI. This article proposes a new method for determining LAI using HJ-1 CCD data. The proposed method uses background knowledge of dynamic land surface processes that are extracted from MODerate resolution Imaging Spectroradiometer (MODIS) LAI 1-km resolution data. To process the uncertainties that arise from using two data sources with different spatial resolutions, the proposed method is implemented in a dynamitic Bayesian network scheme by integrating a LAI dynamic process model and a canopy reflectance model with remotely sensed data. Validation results showed that the determination coefficient between estimated and measured LAI was 0.791, and the RMSE was 0.61. This method can enhance the accuracy of the retrieval results while retaining the time series variation characteristics of the vegetation LAI. The results suggest that this algorithm can be widely applied to determining high-resolution leaf area indices using data from China HJ-1 satellite even if information from single angle observations are insufficient for quantitative application
11. Early-season agricultural drought: detection, assessment and monitoring using Shortwave Angle and Slope Index (SASI) data.
Science.gov (United States)
Das, Prabir Kumar; Murthy, Srirama C; Seshasai, M V R
2013-12-01
Early season or crop-planting-period (ES/CPP) drought conditions have become a recurrent phenomenon in tropical countries like India, due to fluctuations in the time of onset and progression of monsoon rains. ES/CPP agricultural drought assessment is a major challenge because of the difficulties in the generation of operational products on soil moisture at larger scales. The present study analyzed the Shortwave Angle Slope Index (SASI) derived from Near Infrared and Shortwave Infrared data of Moderate Resolution Imaging Spectroradiometer, for tracking surface moisture changes and assessing the agricultural drought conditions during ES/CPP, over Andhra Pradesh state, India. It was found that in-season progression of SASI was well correlated with rainfall and crop planting patterns in different districts of the study area state in both drought and normal years. Rainfall occurrence, increase in crop planted area, and decrease in SASI were in chronological synchronization in the season. Change in SASI from positive to negative values is a unique indication of dryness to wetness shift in the season. Duration of positive SASI values indicated the persistence of agricultural drought in the crop planting period. Mean SASI values were able to discriminate an area which was planted in normal year and unplanted in drought year. SASI thresholds provide an approximate and rapid estimate of the crop planting favorable area in a region which is useful to assess the impact of drought. Thus, SASI is a potential index to strengthen the existing operational drought monitoring systems. Further work needs to be on the integration of multiple parameters-SASI, soil texture, soil depth, rainfall and cropping pattern, to evolve a geospatial product on crop planting favorable areas. Such products pave the way for quantification of drought impact on agriculture in the early part of the season, which is a major inadequacy in the current drought monitoring system. PMID:23793539
12. EEG Signals Analysis Using Multiscale Entropy for Depth of Anesthesia Monitoring during Surgery through Artificial Neural Networks.
Science.gov (United States)
Liu, Quan; Chen, Yi-Feng; Fan, Shou-Zen; Abbod, Maysam F; Shieh, Jiann-Shing
2015-01-01
In order to build a reliable index to monitor the depth of anesthesia (DOA), many algorithms have been proposed in recent years, one of which is sample entropy (SampEn), a commonly used and important tool to measure the regularity of data series. However, SampEn only estimates the complexity of signals on one time scale. In this study, a new approach is introduced using multiscale entropy (MSE) considering the structure information over different time scales. The entropy values over different time scales calculated through MSE are applied as the input data to train an artificial neural network (ANN) model using bispectral index (BIS) or expert assessment of conscious level (EACL) as the target. To test the performance of the new index's sensitivity to artifacts, we compared the results before and after filtration by multivariate empirical mode decomposition (MEMD). The new approach via ANN is utilized in real EEG signals collected from 26 patients before and after filtering by MEMD, respectively; the results show that is a higher correlation between index from the proposed approach and the gold standard compared with SampEn. Moreover, the proposed approach is more structurally robust to noise and artifacts which indicates that it can be used for monitoring the DOA more accurately. PMID:26491464
13. Monitoring and mapping leaf area index of rubber and oil palm in small watershed area
International Nuclear Information System (INIS)
Existing conventional methods to determine LAI are tedious and time consuming for implementation in small or large areas. Thus, raster LAI data which are available free were downloaded for 4697.60 km2 of Sungai Muar watershed area in Johor. The aim of this study is to monitor and map LAI changes of rubber and oil palm throughout the years from 2002 to 2008. Raster datasets of LAI value were obtained from the National Aeronautics and Space Administration (NASA) website of available years from 2002 to year 2008. These data, were mosaicked and subset utilizing ERDAS Imagine 9.2. Next, the LAI raster dataset was multiplied by a scale factor of 0.1 to derive the final LAI value. Afterwards, to determine LAI values of rubber and oil palms, the boundaries of each crop from land cover data of the years 2002, 2006 and 2008 were exploited to overlay with LAI raster dataset. A total of 5000 sample points were generated utilizing the Hawths Tool (extension in ARcGIS 9.2) within these boundaries area and utilized for extracting LAI value of oil palm and rubber. In integration, a wide range of literature review was conducted as a guideline to derive LAI value of oil palm and rubber which range from 0 to 6. The results show, an overall mean LAI value from year 2002 to 2008 as decremented from 4.12 to 2.5 due to land cover transition within these years. In 2002, the mean LAI value of rubber and oil palm is 2.65 and 2.53 respectively. Meanwhile in 2006, the mean LAI value for rubber and oil palm is 2.54 and 2.82 respectively. In 2008, the mean LAI value for both crops is 0.85 for rubber and 1.04 for oil palm. In conclusion, apart from the original function of LAI which is related to the growth and metabolism of vegetation, the changes of LAI values from year 2002 to 2008 also capable to explain the process of land cover changes in a watershed area
14. Indian deep-sea environment experiment (INDEX): Monitoring the restoration of marine enviroment after artificial disturbance to simulate deep-sea mining in central Indian Basin
Digital Repository Service at National Institute of Oceanography (India)
Sharma, R.
the restoration of marine environment after artificial disturbance to simulate deep-sea mining in Central Indian Basin Guest Editor Rahul Sharma Note from guest editor A special issue on Indian Deep-sea Environment Experiment (INDEX) conducted by the scientists... Erratum Marine Georesources and Geotechnology vol. 23, no. 4 (September–December 2005) was a special issue, but this was not indicated. The correct special issue information is below. Indian Deep-Sea Environment Experiment (INDEX): Monitoring...
15. Bi-spectral beam extraction in combination with a focusing feeder
CERN Document Server
Zendler, C; Nekrassov, D; Cussen, L D; Strobl, M
2013-01-01
Bi-spectral beam extraction combines neutrons from two different kind of moderators into one beamline, expanding the spectral range and thereby the utilization of an instrument. This idea can be realized by a mirror that reflects long wavelength neutrons from an off-axis colder moderator into a neutron guide aligned with another moderator emitting neutrons with shorter wavelengths which will be transmitted through the mirror. The mirror used in such systems is typically several meters long, which is a severe disadvantage because it reduces the possible length of a focusing device in design concepts requiring a narrow beam at a short distance from the source, as used in many instruments under development for the planned European Spallation Source (ESS). We propose a shortened extraction system consisting of several mirrors, and show that such an extraction system is better suited for combination with a feeder in an eye of the needle design, illustrated here in the context of a possible ESS imaging beamline.
16. Bi-spectral beam extraction in combination with a focusing feeder
Energy Technology Data Exchange (ETDEWEB)
Zendler, C., E-mail: [email protected] [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); ESS Design Update Programme (Germany); Lieutenant, K.; Nekrassov, D.; Cussen, L.D. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); ESS Design Update Programme (Germany); Strobl, M. [European Spallation Source ESS AB, Box 176, 22100 Lund (Sweden)
2013-03-11
Bi-spectral beam extraction combines neutrons from two different kinds of moderators into one beamline, expanding the spectral range and thereby the utilization of an instrument. This idea can be realized by a mirror that reflects long wavelength neutrons from an off-axis colder moderator into a neutron guide aligned with another moderator emitting neutrons with shorter wavelengths which will be transmitted through the mirror. The mirror used in such systems is typically several meters long, which is a severe disadvantage because it reduces the possible length of a focusing device in design concepts requiring a narrow beam at a short distance from the source, as used in many instruments under development for the planned European Spallation Source (ESS). We propose a shortened extraction system consisting of several mirrors and show that such an extraction system is better suited for combination with a feeder in an eye of the needle design, illustrated here in the context of a possible ESS imaging beamline.
17. Application of “taxocene surrogation” and “taxonomic sufficiency” concepts to fish farming environmental monitoring. Comparison of BOPA index versus polychaete assemblage structure
OpenAIRE
Aguado Giménez, Felipe; Gairin Deulofeu, Joan Ignasi; Martinez-Garcia, Elena; Fernandez-Gonzalez, Victoria; Ballester-Moltó, Mateo; Cerezo-Valverde, Jesús; Sanchez-Jerez, Pablo
2015-01-01
“Taxocene surrogation” and “taxonomic sufficiency” concepts were applied to the monitoring of soft bottoms macrobenthic assemblages influenced by fish farming following two approaches. Polychaete assemblage evaluation through multivariate analysis and the benthic index BOPA were compared. Six fish farms along the Spanish Mediterranean coast were monitored. Polychaete assemblage provided a suitable picture of the impact gradient, being correlated with total free sulphides. BOPA did not support...
18. A quest to increase safety of anesthetics by advancements in anesthesia monitoring: scientometric analysis
Directory of Open Access Journals (Sweden)
Vlassakov KV
2015-05-01
Full Text Available Kamen V Vlassakov, Igor Kissin Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA Abstract: The aim of this study was to assess progress in the field of anesthesia monitoring over the past 40 years using scientometric analysis. The following scientometric indexes were used: popularity indexes (general and specific, representing the proportion of articles on either a topic relative to all articles in the field of anesthetics (general popularity index, GPI or the subfield of anesthesia monitoring (specific popularity index, SPI; index of change (IC, representing the degree of growth in publications on a topic from one period to the next; and index of expectations (IE, representing the ratio of the number of articles on a topic in the top 20 journals relative to the number of articles in all (>5,000 biomedical journals covered by PubMed. Publications on 33 anesthesia-monitoring topics were assessed. Our analysis showed that over the past 40 years, the rate of rise in the number of articles on anesthesia monitoring was exponential, with an increase of more than eleven-fold, from 296 articles over the 5-year period 1974–1978 to 3,394 articles for 2009–2013. This rise profoundly exceeded the rate of rise of the number of articles on general anesthetics. The difference was especially evident with the comparison of the related GPIs: stable growth of the GPI for anesthesia monitoring vs constant decline in the GPI for general anesthetics. By the 2009–2013 period, among specific monitoring topics introduced after 1980, the SPI index had a meaningful magnitude (≥1.5 in 9 of 24 topics: Bispectral Index (7.8, Transesophageal Echocardiography (4.2, Electromyography (2.8, Pulse Oximetry (2.4, Entropy (2.3, Train-of-four (2.3, Capnography (1.9, Pulse Contour (1.9, and Electrical Nerve Stimulation for neuromuscular monitoring (1.6. Only one of these topics (Pulse
19. A quest to increase safety of anesthetics by advancements in anesthesia monitoring: scientometric analysis.
Science.gov (United States)
Vlassakov, Kamen V; Kissin, Igor
2015-01-01
The aim of this study was to assess progress in the field of anesthesia monitoring over the past 40 years using scientometric analysis. The following scientometric indexes were used: popularity indexes (general and specific), representing the proportion of articles on either a topic relative to all articles in the field of anesthetics (general popularity index, GPI) or the subfield of anesthesia monitoring (specific popularity index, SPI); index of change (IC), representing the degree of growth in publications on a topic from one period to the next; and index of expectations (IE), representing the ratio of the number of articles on a topic in the top 20 journals relative to the number of articles in all (>5,000) biomedical journals covered by PubMed. Publications on 33 anesthesia-monitoring topics were assessed. Our analysis showed that over the past 40 years, the rate of rise in the number of articles on anesthesia monitoring was exponential, with an increase of more than eleven-fold, from 296 articles over the 5-year period 1974-1978 to 3,394 articles for 2009-2013. This rise profoundly exceeded the rate of rise of the number of articles on general anesthetics. The difference was especially evident with the comparison of the related GPIs: stable growth of the GPI for anesthesia monitoring vs constant decline in the GPI for general anesthetics. By the 2009-2013 period, among specific monitoring topics introduced after 1980, the SPI index had a meaningful magnitude (≥1.5) in 9 of 24 topics: Bispectral Index (7.8), Transesophageal Echocardiography (4.2), Electromyography (2.8), Pulse Oximetry (2.4), Entropy (2.3), Train-of-four (2.3), Capnography (1.9), Pulse Contour (1.9), and Electrical Nerve Stimulation for neuromuscular monitoring (1.6). Only one of these topics (Pulse Contour) demonstrated (in 2009-2013) high values for both IC and IE indexes (76 and 16.9, respectively), indicating significant recent progress. We suggest that rapid growth in the field of
20. EEG Signals Analysis Using Multiscale Entropy for Depth of Anesthesia Monitoring during Surgery through Artificial Neural Networks
Directory of Open Access Journals (Sweden)
Quan Liu
2015-01-01
Full Text Available In order to build a reliable index to monitor the depth of anesthesia (DOA, many algorithms have been proposed in recent years, one of which is sample entropy (SampEn, a commonly used and important tool to measure the regularity of data series. However, SampEn only estimates the complexity of signals on one time scale. In this study, a new approach is introduced using multiscale entropy (MSE considering the structure information over different time scales. The entropy values over different time scales calculated through MSE are applied as the input data to train an artificial neural network (ANN model using bispectral index (BIS or expert assessment of conscious level (EACL as the target. To test the performance of the new index’s sensitivity to artifacts, we compared the results before and after filtration by multivariate empirical mode decomposition (MEMD. The new approach via ANN is utilized in real EEG signals collected from 26 patients before and after filtering by MEMD, respectively; the results show that is a higher correlation between index from the proposed approach and the gold standard compared with SampEn. Moreover, the proposed approach is more structurally robust to noise and artifacts which indicates that it can be used for monitoring the DOA more accurately.
1. An Evaluation of Using Population Pharmacokinetic Models to Estimate Pharmacodynamic Parameters for Propofol and Bispectral Index in Children
NARCIS (Netherlands)
Coppens, Marc J.; Eleveld, Douglas J.; Proost, Johannes H.; Marks, Luc A. M.; Van Bocxlaer, Jan F. P.; Vereecke, Hugo; Absalom, Anthony R.; Struys, Michel M. R. F.
2011-01-01
Background: To study propofol pharmacodynamics in a clinical setting a pharmacokinetic model must be used to predict drug plasma concentrations. Some investigators use a population pharmacokinetic model from existing literature and minimize the pharmacodynamic objective function. The purpose of the
2. The Europe 2020 Index
Science.gov (United States)
Pasimeni, Paolo
2013-01-01
This paper presents a new index to quantify, measure and monitor the progress towards the objectives of the Europe 2020 strategy. This index is based on a set of relevant, accepted, credible, easy to monitor and robust indicators presented by the European Commission at the time the strategy was launched. The internal analysis of the index shows…
3. Comparing subjective and objective indicators to describe the national entrepreneurial context: the Global Entrepreneurship Monitor and the Global Competitiveness Index contributions
Directory of Open Access Journals (Sweden)
Alicia Coduras
2013-01-01
Full Text Available Entrepreneurship research is progressing towards the construction of indexes that integrate the information of the three predominant approaches: the entrepreneurial activity output; the population’s entrepreneurial behavior, values and aspirations; and the context in which entrepreneurship takes place. In this study we compare the Global Competitiveness Index data, one of the objective sources of information selected among those recognized as descriptors of national contexts, with the national entrepreneurial context qualitative information provided by the Global Entrepreneurship Monitor. The main purpose of this research is to contribute to the knowledge of entrepreneurial context sources of information by opening a discussion around the usefulness and contribution that could make the Global Entrepreneurship Monitor source in this field, and to determine if it is recommendable to proceed to its formal validation in the short time. The obtained results evidence that the two sources do not overlap to the degree of substituting one by the other and that the Global Entrepreneurship Monitor provides relevant qualitative details about the state of entrepreneurial context that are interesting to complement the Global Competitiveness Index information. The conclusion is to recommend the formal validation of this source, being also necessary to make comparisons with other relevant sources and to clear up its role in the progress of the integrated indexes construction.
4. Inter-Comparison of ASTER and MODIS Surface Reflectance and Vegetation Index Products for Synergistic Applications to Natural Resource Monitoring
Science.gov (United States)
Miura, Tomoaki; Yoshioka, Hiroki; Fujiwara, Kayo; Yamamoto, Hirokazu
2008-01-01
Synergistic applications of multi-resolution satellite data have been of a great interest among user communities for the development of an improved and more effective operational monitoring system of natural resources, including vegetation and soil. In this study, we conducted an inter-comparison of two remote sensing products, namely, visible/near-infrared surface reflectances and spectral vegetation indices (VIs), from the high resolution Advanced Thermal Emission and Reflection Radiometer (ASTER) (15 m) and lower resolution Moderate Resolution Imaging Spectroradiometer (MODIS) (250 m – 500 m) sensors onboard the Terra platform. Our analysis was aimed at understanding the degree of radiometric compatibility between the two sensors' products due to sensor spectral bandpasses and product generation algorithms. Multiple pairs of ASTER and MODIS standard surface reflectance products were obtained at randomly-selected, globally-distributed locations, from which two types of VIs were computed: the normalized difference vegetation index and the enhanced vegetation indices with and without a blue band. Our results showed that these surface reflectance products and the derived VIs compared well between the two sensors at a global scale, but subject to systematic differences, of which magnitudes varied among scene pairs. An independent assessment of the accuracy of ASTER and MODIS standard products, in which “in-house” surface reflectances were obtained using in situ Aeronet atmospheric data for comparison, suggested that the performance of the ASTER atmospheric correction algorithm may be variable, reducing overall quality of its standard reflectance product. Atmospheric aerosols, which were not corrected for in the ASTER algorithm, were found not to impact the quality of the derived reflectances. Further investigation is needed to identify the sources of inconsistent atmospheric correction results associated with the ASTER algorithm, including additional quality
5. Inter-Comparison of ASTER and MODIS Surface Reflectance and Vegetation Index Products for Synergistic Applications to Natural Resource Monitoring
Directory of Open Access Journals (Sweden)
Hirokazu Yamamoto
2008-04-01
Full Text Available Synergistic applications of multi-resolution satellite data have been of a great interest among user communities for the development of an improved and more effective operational monitoring system of natural resources, including vegetation and soil. In this study, we conducted an inter-comparison of two remote sensing products, namely, visible/near-infrared surface reflectances and spectral vegetation indices (VIs, from the high resolution Advanced Thermal Emission and Reflection Radiometer (ASTER (15 m and lower resolution Moderate Resolution Imaging Spectroradiometer (MODIS (250 m – 500 m sensors onboard the Terra platform. Our analysis was aimed at understanding the degree of radiometric compatibility between the two sensors’ products due to sensor spectral bandpasses and product generation algorithms. Multiple pairs of ASTER and MODIS standard surface reflectance products were obtained at randomly-selected, globally-distributed locations, from which two types of VIs were computed: the normalized difference vegetation index and the enhanced vegetation indices with and without a blue band. Our results showed that these surface reflectance products and the derived VIs compared well between the two sensors at a global scale, but subject to systematic differences, of which magnitudes varied among scene pairs. An independent assessment of the accuracy of ASTER and MODIS standard products, in which “in-house†surface reflectances were obtained using in situ Aeronet atmospheric data for comparison, suggested that the performance of the ASTER atmospheric correction algorithm may be variable, reducing overall quality of its standard reflectance product. Atmospheric aerosols, which were not corrected for in the ASTER algorithm, were found not to impact the quality of the derived reflectances. Further investigation is needed to identify the sources of inconsistent atmospheric correction results
6. Using Social Media to Detect Outdoor Air Pollution and Monitor Air Quality Index (AQI: A Geo-Targeted Spatiotemporal Analysis Framework with Sina Weibo (Chinese Twitter.
Directory of Open Access Journals (Sweden)
Wei Jiang
Full Text Available Outdoor air pollution is a serious problem in many developing countries today. This study focuses on monitoring the dynamic changes of air quality effectively in large cities by analyzing the spatiotemporal trends in geo-targeted social media messages with comprehensive big data filtering procedures. We introduce a new social media analytic framework to (1 investigate the relationship between air pollution topics posted in Sina Weibo (Chinese Twitter and the daily Air Quality Index (AQI published by China's Ministry of Environmental Protection; and (2 monitor the dynamics of air quality index by using social media messages. Correlation analysis was used to compare the connections between discussion trends in social media messages and the temporal changes in the AQI during 2012. We categorized relevant messages into three types, retweets, mobile app messages, and original individual messages finding that original individual messages had the highest correlation to the Air Quality Index. Based on this correlation analysis, individual messages were used to monitor the AQI in 2013. Our study indicates that the filtered social media messages are strongly correlated to the AQI and can be used to monitor the air quality dynamics to some extent.
7. The implementation of an aquatic toxicity index as a water quality monitoring tool in the Olifants River (Kruger National Park
Directory of Open Access Journals (Sweden)
V. Wepener
1999-01-01
Full Text Available Large sets of water quality data can leave water quality managers and decision-makers totally overwhelmed. In order to convey the interpretation of the data in a simplified and understandable manner, the water quality results from bi-monthly surveys undertaken at seven different sampling sites in the Letaba, Olifants, and Selati rivers over a two year period (February 1990 to April 1992 were reduced to index values, using a water quality index. The water quality index (Aquatic Toxicity Index or ATI revealed spatial and temporal trends. The higher index values, recorded for the sampling sites towards the eastern part of the Kruger National Park (KNP, revealed that the water quality was better than the quality measured in the Olifants River on the western bound-ary. The lowest index values were calculated for the Selati River, with index values consistently below 50. Index values indicate that the water quality in the Selati River was unsuitable for supporting normal physiological processes in fish. The water quality of the Selati River had an immediate impact on the water quality of the Olifants River directly below the confluence. Lower index values recorded at sites further downstream was also attributed to the influence of the Selati River since there are no known point sources of contaminants within the boundaries of the KNP. The index scores also elucidated temporal trends with lower scores evident during winter months. This was due to reduced flow in the Olifants River and a greater contribution of contaminated water from the Selati River. Index values increased following the first seasonal rains due to a dilution effect. Very low index values were recorded at certain sites during flood periods due to increased turbidity, reduced oxygen, and increased metal concentrations.
8. Using Social Media to Detect Outdoor Air Pollution and Monitor Air Quality Index (AQI): A Geo-Targeted Spatiotemporal Analysis Framework with Sina Weibo (Chinese Twitter)
OpenAIRE
Jiang, Wei; Wang, Yandong; Tsou, Ming-Hsiang; Fu, Xiaokang
2015-01-01
Outdoor air pollution is a serious problem in many developing countries today. This study focuses on monitoring the dynamic changes of air quality effectively in large cities by analyzing the spatiotemporal trends in geo-targeted social media messages with comprehensive big data filtering procedures. We introduce a new social media analytic framework to (1) investigate the relationship between air pollution topics posted in Sina Weibo (Chinese Twitter) and the daily Air Quality Index (AQI) pu...
9. Myocardial performance index: prediction and monitoring of remodeling and functioning of the left ventricle after first myocardial infarction
OpenAIRE
2010-01-01
Introduction. Dynamic changing of left ventricular geometry and contractile state after acute myocardial infarction is responsible for various aspects of left ventricular remodeling and dysfunction. A number of studies have shown that myocardial performance index allows prediction of acute myocardial infarction complications. The objective of our study was to determine the power of myocardial performance index to predict and assess the severity of left ventricular remodeling, systolic and dia...
10. Application of "taxocene surrogation" and "taxonomic sufficiency" concepts to fish farming environmental monitoring. Comparison of BOPA index versus polychaete assemblage structure.
Science.gov (United States)
Aguado-Giménez, F; Gairín, J I; Martinez-Garcia, E; Fernandez-Gonzalez, V; Ballester Moltó, M; Cerezo-Valverde, J; Sanchez-Jerez, P
2015-02-01
"Taxocene surrogation" and "taxonomic sufficiency" concepts were applied to the monitoring of soft bottoms macrobenthic assemblages influenced by fish farming following two approaches. Polychaete assemblage evaluation through multivariate analysis and the benthic index BOPA were compared. Six fish farms along the Spanish Mediterranean coast were monitored. Polychaete assemblage provided a suitable picture of the impact gradient, being correlated with total free sulphides. BOPA did not support the impact gradient described by the polychaete assemblage, providing erroneous categorizations. The inclusion of several polychaete families, which were locally identified as indicative of affection to recalculate BOPA, resulted in an improved diagnosis and correlation with the impact gradient. Nevertheless, frequent misclassifications occurred. These results suggest that the structure of polychaete families, sulphides and granulometry conform an appropriate strategy for fish farming monitoring. Biotic indices need to be specifically designed for concrete activities, and regionally validated, because of the environmental plasticity of benthic invertebrates. PMID:25460059
11. Environmental vulnerability, assessment, and monitoring of grazing systems under index-based livestock insurance programs in East Africa
Science.gov (United States)
Our goal is to characterize and monitor feedbacks between innovative insurance products and ecosystem services in resource poor environments. Our team is integrating longitudinal field-based measurements and monitoring protocols to quantify grazing animal impact related to the implementation of an ...
12. Water use benefit index as a tool for community-based monitoring of water related trends in the Great Barrier Reef region
Science.gov (United States)
Smajgl, A.; Larson, S.; Hug, B.; De Freitas, D. M.
2010-12-01
SummaryThis paper presents a tool for documenting and monitoring water use benefits in the Great Barrier Reef catchments that allows temporal and spatial comparison along the region. Water, water use benefits and water allocations are currently receiving much attention from Australian policy makers and conservation practitioners. Because of the inherent complexity and variability in water quality, it is essential that scientific information is presented in a meaningful way to policy makers, managers and ultimately, to the general public who have to live with the consequences of the decisions. We developed an inexpensively populated and easily understandable water use benefit index as a tool for community-based monitoring of water related trends in the Great Barrier Reef region. The index is developed based on a comparative list of selected water-related indices integrating attributes across physico-chemical, economic, social, and ecological domains currently used in the assessment of water quality, water quantity and water use benefits in Australia. Our findings indicate that the proposed index allows the identification of water performance indicators by temporal and spatial comparisons. Benefits for decision makers and conservation practitioners include a flexible way of prioritization towards the domain with highest concern. The broader community benefits from a comprehensive and user-friendly tool, communicating changes in water quality trends more effectively.
13. Assessing the potential of SWVI (Soil Wetness Variation Index for hydrological risk monitoring by means of satellite microwave observations
Directory of Open Access Journals (Sweden)
T. Lacava
2005-01-01
Full Text Available In the last years satellite remote sensing applications in hydrology have considerably progressed. A new multi-temporal satellite data-analysis approach has been recently suggested in order to estimate space-time changes of geophysical parameters possibly related to the increase of environmental and hydro-geological hazards. Such an approach has been already used both for flooded area mapping (using AVHRR data and for soil wetness index estimation (using AMSU data. In this work, a preliminary sensitivity analysis of the proposed Soil Wetness Variation Index (SWVI is made in the case of low intensity meteorological events by the comparison with hydrological (precipitation data. This analysis, as a first step of a more complex work in progress, is targeted to a first evaluation of the reliability of the SWVI in describing soil response to precipitations of different duration and intensity.
14. Assessing the potential of SWVI (Soil Wetness Variation Index) for hydrological risk monitoring by means of satellite microwave observations
OpenAIRE
Lacava, T.; Greco, M; Leo, E. V.; Martino, G.; Pergola, N.; Romano, F.; Sannazzaro, F.; V. Tramutoli
2005-01-01
In the last years satellite remote sensing applications in hydrology have considerably progressed. A new multi-temporal satellite data-analysis approach has been recently suggested in order to estimate space-time changes of geophysical parameters possibly related to the increase of environmental and hydro-geological hazards. Such an approach has been already used both for flooded area mapping (using AVHRR data) and for soil wetness index estimation (using AMSU data). ...
15. Spectral Reflectance and Vegetation Index Changes in Deciduous Forest Foliage Following Tree Removal: Potential for Deforestation Monitoring
Science.gov (United States)
Peng, D.; Hu, Y.; Li, Z.
2016-05-01
It is important to detect and quantify deforestation to guide strategic decisions regarding environment, socioeconomic development, and climate change. In the present study, we conducted a field experiment to examine spectral reflectance and vegetation index changes in poplar and locust tree foliage with different leaf area indices over the course of three sunny days, following tree removal from the canopy. The spectral reflectance of foliage from harvested trees was measured using an ASD FieldSpec Prospectroradiometer; synchronous meteorological data were also obtained. We found that reflectance in short-wave infrared and red-edge reflectance was more time sensitive after tree removal than reflectance in other spectral regions, and that the normalized difference water index (NDWI) and the red-edge chlorophyll index (CIRE) were the preferred indicators of these changes from several indices evaluated. Synthesized meteorological environments were found to influence water and chlorophyll contents after tree removal, and this subsequently changed the spectral canopy reflectance. Our results indicate the potential for such tree removal to be detected with NDWI or CIRE from the second day of a deforestation event.
16. Monitoring the tail current contribution to the Dcx index with NOAA/POES satellites: differences between CME and HSS driven storms
Science.gov (United States)
Asikainen, T.; Maliniemi, V.; Mursula, K.
2012-04-01
It is well known that, in addition to the ring current, also other current systems like the magnetopause currents and the tail current have a significant contribution to the Dcx index. While the effect of the magnetopause currents are typically removed by correcting for the solar wind pressure, the effects of the tail current are less well understood and have received less attention. Still, some recent studies have shown that the tail current can have a significant and even a dominant contribution to the Dst index at least during the main phase of moderate storms. We have developed a semi-empirical model that expresses the Dcx index as a sum of ring current, tail current and magnetopause contributions. In the model, the tail current is monitored by observing the location of the night-side isotropic boundary of energetic protons using the MEPED energetic particle instrument onboard NOAA/POES satellites. We briefly present here the model paying particular attention to the tail current and the solar wind parameters driving it. We apply the model to a set of magnetic storms driven by coronal mass ejections (CME) and high speed solar wind streams (HSS), and discuss the differences in the tail and ring current response between these two drivers.
17. Correlation Between Toluene Environmental Monitoring and Biological Index of Urinary Hippuric Acid of Workers in the Coke Industry
OpenAIRE
MM Amin; Kalantari, A.; N BASHARDOOST; AR Bahrami; M. Rismanchian; Gh Mirsatari; Mansouri, F.
2007-01-01
Introduction: Toluene is an organic solvent that it is one of the byproducts in the coke industry. Exposure to toluene causes central nervous system dysfunction and others disorders. Many workers are exposed to toluene due to leakage from tracks. Therefore the aim of this study was to determine the levels of exposure through environmental and biological monitoring of toluene Methods: Air toluene sampling of air inhaled by 36 coke oven workers was done by using activated charcoal tubes and per...
18. Application of flood index in monitoring Flood-plain ecosystems (by the example of the Middle Ob flood-plain)
OpenAIRE
Bolotnov, V. P.
2007-01-01
The concept of regional hydroecological monitoring has been developed for the flood-plain of the Middle Ob. Its object is to control the state of flood-plain ecosystem productivity for organization of scientific, regional-adopted and ecologically regulated nature management. For this purpose hydroecological zoning of flood-plain territory performed, the most representative stations of water-gauge observations for each flood-plain zone organized, the scheme of flood-plain flooding was prepared...
19. Inter-Comparison of ASTER and MODIS Surface Reflectance and Vegetation Index Products for Synergistic Applications to Natural Resource Monitoring
OpenAIRE
Hirokazu Yamamoto; Kayo Fujiwara; Hiroki Yoshioka; Tomoaki Miura
2008-01-01
Synergistic applications of multi-resolution satellite data have been of a great interest among user communities for the development of an improved and more effective operational monitoring system of natural resources, including vegetation and soil. In this study, we conducted an inter-comparison of two remote sensing products, namely, visible/near-infrared surface reflectances and spectral vegetation indices (VIs), from the high resolution Advanced Thermal Emission and Reflection Radiometer ...
20. Application of Drought Index in Daily Monitoring in Shanxi%干旱指数在山西逐日监测中的适用性研究
Institute of Scientific and Technical Information of China (English)
赵海燕; 侯美亭; 刘文平; 马雅丽
2014-01-01
综合气象干旱指数（CI）和标准化降水指数（SPI）在逐日监测中往往会出现干旱突然加重的现象，这是由于某时段内每日降水量对当前干旱的发展贡献是等权重的。本文基于线性递减非等权重的方法对CI进行了修正，同时对加权降水量（WAP）进行了标准化（Standard WAP Index，SWI）。以山西为例，通过对比CI 修正前后，即CI 和CI_new（CI 修正后），与SPI 和SWI 在不连续加重现象（UED）的总体分布、典型事例干旱演变特征以及与土壤湿度相关性等方面的差异，分析了4种干旱指数对山西逐日干旱演变的监测能力。结果表明：1）CI_new出现UED的次数较CI有了明显下降， SWI出现UED的次数也比SPI有了大幅的减少，且SWI在这4种指数中是出现UED次数最少的指数；2）CI_new和SWI较CI和SPI与同期土壤湿度的相关性均有所提高，表明修正后的CI_new和SWI更加符合土壤湿度的变化，更能反映土壤干旱的演变规律。针对干旱发展过程中不连续加重的现象，通过非等权重方法有效地减少了该现象的发生。%The meteorological composite drought index (CI)and the standard precipitation index (SPI)are usually used as effective daily drought monitoring indexes in the whole country.However,there are many uncontinuous enhancement of drought(UED)in devel-opment of drought process at many stations,because daily precipitation in certain period are calculated by equal weighted coefficients in the contribution of present drought development.In fact,the contribution of precipitation today is bigger than that of precipitation twen-ty nine days ago.In this paper the standard precipitation index (SPI)and the meteorological composite drought Index (CI)were both modified.Modified SPI(SWI)was based on weighted average precipitation (WAP),and modified CI (CI_new)was calculated by u-sing linear decreasing unequal weight method.Taking an example of Shanxi
1. The Application of the Environmental Index Correlation on Monitoring Data Auditing%运用各种相关性审核环境监测数据
Institute of Scientific and Technical Information of China (English)
龚坚艰; 辛红云
2016-01-01
Data auditing is one of the most importance steps in qual-ity assurance for environmental monitoring ,there are many kinds of methods for data auditing. The relativity of environmental index was sum-marized with the correlation analysis of environmental data ,and that was used to audit environmental data ,coming through with reference.%数据审核是环境监测质量保证的重要环节之一，数据审核的方法有许多种，文章从监测数据中各环境指标之间的相关性分析出发，对各环境指标间的相关性进行总结，并将其应用于数据合理性的审核，具有借鉴意义。
2. Correlation Between Toluene Environmental Monitoring and Biological Index of Urinary Hippuric Acid of Workers in the Coke Industry
Directory of Open Access Journals (Sweden)
MM Amin
2007-04-01
Full Text Available Introduction: Toluene is an organic solvent that it is one of the byproducts in the coke industry. Exposure to toluene causes central nervous system dysfunction and others disorders. Many workers are exposed to toluene due to leakage from tracks. Therefore the aim of this study was to determine the levels of exposure through environmental and biological monitoring of toluene Methods: Air toluene sampling of air inhaled by 36 coke oven workers was done by using activated charcoal tubes and personal sampling pumps. At the end of the shift, urine samples of workers and control group were collected by urine samplers. Air toluene was determined by GC, urinary hippuric acid by HPLC and urine creatinine level was determined by auto analyzer. Results: The mean of air toluene and urinary hippuric acid levels in exposed and control samples were 14.34 ppm, 0.33 and 0.28 g/g creatinine. Air toluene and urinary hippuric acid showed a correlation of r = 0.8. Conclusion: Toluene TWA was lower than the TLV-TWA (p=0.000. Urinary hippuric acid concentration was also lower than the BEI (p=0.008. Difference between exposed and unexposed group was not significant. This study showed that hippuric acid because of its interaction with background factors can not be used as a sensitive biomarker for biomonitoring.
3. TOMS Absorbing Aerosol Index
Data.gov (United States)
Washington University St Louis — TOMS_AI_G is an aerosol related dataset derived from the Total Ozone Monitoring Satellite (TOMS) Sensor. The TOMS aerosol index arises from absorbing aerosols such...
4. Monitor
Data.gov (United States)
US Agency for International Development — A custom-built, dual-language (English and Spanish) system (http://www.monitor.net.co/) developed by DevTech that debuted in January 2011. It features a central PMP...
5. Capnography and the Bispectral Index—Their Role in Pediatric Sedation: A Brief Review
OpenAIRE
Maria Sammartino; Barbara Volpe; Fabio Sbaraglia; Rossella Garra; Alessandro D'Addessi
2010-01-01
Sedation in children is increasingly emerging as a minimally invasive technique that may be associated with local anaesthesia or diagnostic and therapeutic procedures which do not necessarily require general anaesthesia. Standard monitoring requirements are not sufficient to ensure an effective control of pulmonary ventilation and deep sedation. Capnography in pediatric sedation assesses the effect of different drugs on the occurrence of respiratory failure and records early indicators of res...
6. Bispectral pairwise interacting source analysis for identifying systems of cross-frequency interacting brain sources from electroencephalographic or magnetoencephalographic signals
Science.gov (United States)
Chella, Federico; Pizzella, Vittorio; Zappasodi, Filippo; Nolte, Guido; Marzetti, Laura
2016-05-01
Brain cognitive functions arise through the coordinated activity of several brain regions, which actually form complex dynamical systems operating at multiple frequencies. These systems often consist of interacting subsystems, whose characterization is of importance for a complete understanding of the brain interaction processes. To address this issue, we present a technique, namely the bispectral pairwise interacting source analysis (biPISA), for analyzing systems of cross-frequency interacting brain sources when multichannel electroencephalographic (EEG) or magnetoencephalographic (MEG) data are available. Specifically, the biPISA makes it possible to identify one or many subsystems of cross-frequency interacting sources by decomposing the antisymmetric components of the cross-bispectra between EEG or MEG signals, based on the assumption that interactions are pairwise. Thanks to the properties of the antisymmetric components of the cross-bispectra, biPISA is also robust to spurious interactions arising from mixing artifacts, i.e., volume conduction or field spread, which always affect EEG or MEG functional connectivity estimates. This method is an extension of the pairwise interacting source analysis (PISA), which was originally introduced for investigating interactions at the same frequency, to the study of cross-frequency interactions. The effectiveness of this approach is demonstrated in simulations for up to three interacting source pairs and for real MEG recordings of spontaneous brain activity. Simulations show that the performances of biPISA in estimating the phase difference between the interacting sources are affected by the increasing level of noise rather than by the number of the interacting subsystems. The analysis of real MEG data reveals an interaction between two pairs of sources of central mu and beta rhythms, localizing in the proximity of the left and right central sulci.
7. Monitoring
Czech Academy of Sciences Publication Activity Database
Ložek, Vojen; Němec, J.
Praha : Consult, 2003 - (Němec, J.), s. 111-115 ISBN 80-902132-4-3 Grant ostatní: Magistrát hlavního města Prahy(CZ) DAG/67/04/000176/2001 Institutional research plan: CEZ:AV0Z3013912 Keywords : monitoring * environmental quality * Prague Subject RIV: DB - Geology ; Mineralogy
8. Monitoring
Science.gov (United States)
... its main source of fuel. To keep your blood sugar level on target and avoid problems with your eyes, kidneys, heart and feet, you should eat right ... better. And monitoring doesn’t stop at measuring blood sugar levels. Because ... blood testing) Eye health (eye exams) Foot health (foot exams and ...
9. Elements regulation during cartilage and bone deformity - potential clinical index in early diagnosis, monitoring and prognosis in children of kashin - beck disease
International Nuclear Information System (INIS)
Background: Kashin-Beck Disease (KBD) is a chronic deforming osteoarthritis starting in early childhood and affecting the cartilage metabolism and endochondral ossification. Selenium (Se) deficiency has been postulated as the major environmental etiological factor for KBD by many studies. Other minerals such as the Manganese (Mn) and calcium (Ca) which don't have uniform distribution in environment are also important elements involved in bone and cartilage formation but their regulation in KBD has been rarely reported. The study was done to investigate the role of Mn and Ca in addition to Se in KBD. Method: In this study, the Se, Mn and Calevels were investigated in children from different groups (KBD group, Healthy group from KBD endemic areas (inner control group), Healthy group (outer control group) from Non KBD areas and KBD group with selenium supplementation). The contents of Mn, S and Ca in serum and hair were analyzed by inductively coupled plasma mass spectrometry. Results: The increased Mn levels of. serum and hair in KBD children were observed compared with normal groups. The Mn and Ca have similar trends in different groups but Se and Mn displayed reversed trends. Conclusions: The Mn and Ca contributed to KBD pathogenesis combined with se in regulation of growth and development. The relative ratio of Mn to Se can be a potential clinical index in early diagnosis, monitoring and prognosis of KBD in children. (author)
10. Time-varying bispectral analysis of visually evoked multi-channel EEG
Science.gov (United States)
Chandran, Vinod
2012-12-01
Theoretical foundations of higher order spectral analysis are revisited to examine the use of time-varying bicoherence on non-stationary signals using a classical short-time Fourier approach. A methodology is developed to apply this to evoked EEG responses where a stimulus-locked time reference is available. Short-time windowed ensembles of the response at the same offset from the reference are considered as ergodic cyclostationary processes within a non-stationary random process. Bicoherence can be estimated reliably with known levels at which it is significantly different from zero and can be tracked as a function of offset from the stimulus. When this methodology is applied to multi-channel EEG, it is possible to obtain information about phase synchronization at different regions of the brain as the neural response develops. The methodology is applied to analyze evoked EEG response to flash visual stimulii to the left and right eye separately. The EEG electrode array is segmented based on bicoherence evolution with time using the mean absolute difference as a measure of dissimilarity. Segment maps confirm the importance of the occipital region in visual processing and demonstrate a link between the frontal and occipital regions during the response. Maps are constructed using bicoherence at bifrequencies that include the alpha band frequency of 8Hz as well as 4 and 20Hz. Differences are observed between responses from the left eye and the right eye, and also between subjects. The methodology shows potential as a neurological functional imaging technique that can be further developed for diagnosis and monitoring using scalp EEG which is less invasive and less expensive than magnetic resonance imaging.
11. Indexing books
CERN Document Server
Mulvany, Nancy C
2009-01-01
Since 1994, Nancy Mulvany's Indexing Books has been the gold standard for thousands of professional indexers, editors, and authors. This long-awaited second edition, expanded and completely updated, will be equally revered.Like its predecessor, this edition of Indexing Books offers comprehensive, reliable treatment of indexing principles and practices relevant to authors and indexers alike. In addition to practical advice, the book presents a big-picture perspective on the nature and purpose of indexes and their role in published works. New to this edition are discus
12. Comparative evaluation of bispectral index system after sedation with midazolam and propofol combined with remifentanil versus ketamine in uncooperative during dental procedures
Directory of Open Access Journals (Sweden)
Alireza Eshghi
2016-01-01
Conclusion: It can be concluded that intravenous sedation technique with PMR combination induces effective and safe sedation, with less pain and more forgetfulness and a shorter recovery time for children 3-7 years of age during dental procedures.
13. Cloud cover over the equatorial eastern Pacific derived from July 1983 International Satellite Cloud Climatology Project data using a hybrid bispectral threshold method
Science.gov (United States)
Minnis, Patrick; Harrison, Edwin F.; Gibson, Gary G.
1987-01-01
A set of visible and IR data obtained with GOES from July 17-31, 1983 is analyzed using a modified version of the hybrid bispectral threshold method developed by Minnis and Harrison (1984). This methodology can be divided into a set of procedures or optional techniques to determine the proper contaminate clear-sky temperature or IR threshold. The various optional techniques are described; the options are: standard, low-temperature limit, high-reflectance limit, low-reflectance limit, coldest pixel and thermal adjustment limit, IR-only low-cloud temperature limit, IR clear-sky limit, and IR overcast limit. Variations in the cloud parameters and the characteristics and diurnal cycles of trade cumulus and stratocumulus clouds over the eastern equatorial Pacific are examined. It is noted that the new method produces substantial changes in about one third of the cloud amount retrieval; and low cloud retrievals are affected most by the new constraints.
14. Index Numbers
OpenAIRE
Diewert, Erwin
2007-01-01
Index numbers are used to aggregate detailed information on prices and quantities into scalar measures of price and quantity levels or their growth. The paper reviews four main approaches to bilateral index number theory where two price and quantity vectors are to be aggregated: fixed basket and average of fixed baskets, stochastic, test or axiomatic and economic approaches. The paper also considers multilateral index number theory where it is necessary to construct price and quantity aggrega...
15. The tree BVOC index
Energy Technology Data Exchange (ETDEWEB)
Simpson, J.R., E-mail: [email protected] [U.S. Forest Service, Pacific Southwest Research Station, Urban Ecosystems and Processes, 1731 Research Park Drive, Davis, CA 95616 (United States); McPherson, E.G. [U.S. Forest Service, Pacific Southwest Research Station, Urban Ecosystems and Processes, 1731 Research Park Drive, Davis, CA 95616 (United States)
2011-08-15
Urban trees can produce a number of benefits, among them improved air quality. Biogenic volatile organic compounds (BVOCs) emitted by some species are ozone precursors. Modifying future tree planting to favor lower-emitting species can reduce these emissions and aid air management districts in meeting federally mandated emissions reductions for these compounds. Changes in BVOC emissions are calculated as the result of transitioning to a lower-emitting species mix in future planting. A simplified method for calculating the emissions reduction and a Tree BVOC index based on the calculated reduction is described. An example illustrates the use of the index as a tool for implementation and monitoring of a tree program designed to reduce BVOC emissions as a control measure being developed as part of the State Implementation Plan (SIP) for the Sacramento Federal Nonattainment Area. - Highlights: > A Tree BVOC index based on reduced emissions from low emitting trees is described. > An example illustrates use of the index as an implementation and monitoring tool. > This index could be useful for including urban trees in air quality mitigation plans. - A tree BVOC index is presented that calculates reduced BVOC emissions from planting lower-emitting urban tree species that has potential application for SIP compliance.
16. The tree BVOC index
International Nuclear Information System (INIS)
Urban trees can produce a number of benefits, among them improved air quality. Biogenic volatile organic compounds (BVOCs) emitted by some species are ozone precursors. Modifying future tree planting to favor lower-emitting species can reduce these emissions and aid air management districts in meeting federally mandated emissions reductions for these compounds. Changes in BVOC emissions are calculated as the result of transitioning to a lower-emitting species mix in future planting. A simplified method for calculating the emissions reduction and a Tree BVOC index based on the calculated reduction is described. An example illustrates the use of the index as a tool for implementation and monitoring of a tree program designed to reduce BVOC emissions as a control measure being developed as part of the State Implementation Plan (SIP) for the Sacramento Federal Nonattainment Area. - Highlights: → A Tree BVOC index based on reduced emissions from low emitting trees is described. → An example illustrates use of the index as an implementation and monitoring tool. → This index could be useful for including urban trees in air quality mitigation plans. - A tree BVOC index is presented that calculates reduced BVOC emissions from planting lower-emitting urban tree species that has potential application for SIP compliance.
17. AP Index
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — Planetary Amplitude index - Bartels 1951. The a-index ranges from 0 to 400 and represents a K-value converted to a linear scale in gammas (nanoTeslas)--a scale that...
18. Afghanistan Index
DEFF Research Database (Denmark)
Linnet, Poul Martin
2007-01-01
information on progress or lack of progress in the reconstruction of the post Taliban Afghanistan. The index is mainly based on information collected on the internet in order to provide quick access to the original source. The index is under development and thus new information will be added on a continuous...
19. GCUBE INDEXING
Directory of Open Access Journals (Sweden)
M.Laxmaiah
2013-07-01
Full Text Available Spatial Online Analytical Processing System involves the non-categorical attribute information also whereas standard online analytical processing system deals with only categorical attributes. Providing spatial information to the data warehouse (DW; two major challenges faced are; 1.Defining and Aggregation of Spatial or Continues values and 2.Representation, indexing, updating and efficient query processing. In this paper, we present GCUBE (Geographical Cube storage and indexing procedure to aggregate the spatial information/Continuous values. We employed the proposed approach storing and indexing using synthetic and real data sets and evaluated its build, update and Query time. It is observed that the proposed procedure offers significant performance advantage.
20. AA Index
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — The geomagnetic aa index provides a long climatology of global geomagnetic activity using 2 antipodal observatories at Greenwich and Melbourne- IAGA Bulletin 37,...
1. Walkability Index
Data.gov (United States)
U.S. Environmental Protection Agency — The Walkabiliy Index dataset characterizes every Census 2010 block group in the U.S. based on its relative walkability. Walkability depends upon characteristics of...
2. Intelligent indexing
International Nuclear Information System (INIS)
In this paper we discuss the relevance of artificial intelligence to the automatic indexing of natural language text. We describe the use of domain-specific semantically-based thesauruses and address the problem of creating adequate knowledge bases for intelligent indexing systems. We also discuss the relevance of the Hilbert space ι2 to the compact representation of documents and to the definition of the similarity of natural language texts. (author). 17 refs., 2 figs
3. Louisiana ESI: INDEX (Index Polygons)
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all the hardcopy cartographic products produced as part of the Environmental Sensitivity Index...
4. Use of Blood Plasma Double Bond (DB-index for Prognosis and Monitoring the Treatment Effectiveness of Patients with Severe Whitlow
Directory of Open Access Journals (Sweden)
Knyazev V.N.
2011-03-01
Full Text Available The aim of the investigation is the assessment of the possibility of blood plasma DB-index use to evaluate the endogenous intoxication level and the treatment effectiveness of whitlow destructive forms. To study the unsaturation level of serum lipids and cell plasma membrane there has been used an ozonation technique by means of a double bond analyzer, elaborated in the M.N. Semyonov Institute of Chemical Physics. The method is based on the interaction between ozone and a (-S=S--bond of an unsaturated organic compound in the equimolar ratio. When treating patients with whitlow using ozone therapy there has been observed the more rapid normalization of a DB-index compared to a traditional treatment.
5. Assessing the potential of SWVI (Soil Wetness Variation Index) for hydrological risk monitoring by means of satellite microwave observations
OpenAIRE
Lacava, T.; Greco, M; Di Leo, E. V.; Martino, G.; Pergola, N.; Romano, F.; Sannazzaro, F.; V. Tramutoli
2005-01-01
In the last years satellite remote sensing applications in hydrology have considerably progressed. A new multi-temporal satellite data-analysis approach has been recently suggested in order to estimate space-time changes of geophysical parameters possibly related to the increase of environmental and hydro-geological hazards. Such an approach has been already used both for flooded area mapping (using AVHRR data) and for soil wetness index estimation (using AMSU data). In this work, a prelimina...
6. Assessing the potential of SWVI (Soil Wetness Variation Index) for hydrological risk monitoring by means of satellite microwave observations
OpenAIRE
Lacava, T.; Greco, M; Di Leo, E. V.; Martino, G.; Pergola, N.; Romano, F.; Sannazzaro, F.; V. Tramutoli
2005-01-01
In the last years satellite remote sensing applications in hydrology have considerably progressed. A new multi-temporal satellite data-analysis approach has been recently suggested in order to estimate space-time changes of geophysical parameters possibly related to the increase of environmental and hydro-geological hazards. Such an approach has been already used both for flooded area mapping (using AVHRR data) and for soil wetness index estimation (using AMSU data). In this work, a prelimin...
7. GCUBE Indexing
Directory of Open Access Journals (Sweden)
M.Laxmaiah
2013-07-01
Full Text Available Spatial Online Analytical Processing System involves the non-categorical attribute information alsowhereas standard online analytical processing system deals with only categorical attributes. Providingspatial information to the data warehouse (DW; twomajor challenges faced are; 1.Defining andAggregation of Spatial or Continues values and 2.Representation, indexing, updating and efficient queryprocessing. In this paper, we present GCUBE (Geographical Cube storage and indexing procedure toaggregate the spatial information/Continuous values. We employed the proposed approach storing andindexing using synthetic and real data sets and evaluated its build, update and Query time. It is observedthat the proposed procedure offers significant performance advantage.
8. Comparison of auditory evoked potentials and the A-line ARX Index for monitoring the hypnotic level during sevoflurane and propofol induction
DEFF Research Database (Denmark)
Litvan, H; Jensen, E W; Revuelta, M; Henneberg, S W; Paniagua, P; Campos, J M; Martínez, P; Caminal, P; Villar Landeira, J M
2002-01-01
Extraction of the middle latency auditory evoked potentials (AEP) by an auto regressive model with exogenous input (ARX) enables extraction of the AEP within 1.7 s. In this way, the depth of hypnosis can be monitored at almost real-time. However, the identification and the interpretation of the a...
9. Comparison of auditory evoked potentials and the A-line ARX Index for monitoring the hypnotic level during sevoflurane and propofol induction
DEFF Research Database (Denmark)
Litvan, H; Jensen, E W; Revuelta, M;
2002-01-01
Extraction of the middle latency auditory evoked potentials (AEP) by an auto regressive model with exogenous input (ARX) enables extraction of the AEP within 1.7 s. In this way, the depth of hypnosis can be monitored at almost real-time. However, the identification and the interpretation of the...
10. Use of Blood Plasma Double Bond (DB)-index for Prognosis and Monitoring the Treatment Effectiveness of Patients with Severe Whitlow
OpenAIRE
Knyazev V.N.; Miroshin S.I.; Evdokimova O.S.; Martusevich A.K.
2011-01-01
The aim of the investigation is the assessment of the possibility of blood plasma DB-index use to evaluate the endogenous intoxication level and the treatment effectiveness of whitlow destructive forms. To study the unsaturation level of serum lipids and cell plasma membrane there has been used an ozonation technique by means of a double bond analyzer, elaborated in the M.N. Semyonov Institute of Chemical Physics. The method is based on the interaction between ozone and a (-S=S-)-bond of an u...
11. Evaluation of the Fourier Frequency Spectrum Peaks of Milk Electrical Conductivity Signals as Indexes to Monitor the Dairy Goats’ Health Status by On-Line Sensors
Directory of Open Access Journals (Sweden)
Mauro Zaninelli
2015-08-01
Full Text Available The aim of this study is a further characterization of the electrical conductivity (EC signal of goat milk, acquired on-line by EC sensors, to identify new indexes representative of the EC variations that can be observed during milking, when considering not healthy (NH glands. Two foremilk gland samples from 42 Saanen goats, were collected for three consecutive weeks and for three different lactation stages (LS: 0–60 Days In Milking (DIM; 61–120 DIM; 121–180 DIM, for a total amount of 1512 samples. Bacteriological analyses and somatic cells counts (SCC were used to define the health status of the glands. With negative bacteriological analyses and SCC < 1,000,000 cells/mL, glands were classified as healthy. When bacteriological analyses were positive or showed a SCC > 1,000,000 cells/mL, glands were classified as NH. For each milk EC signal, acquired on-line and for each gland considered, the Fourier frequency spectrum of the signal was calculated and three representative frequency peaks were identified. To evaluate data acquired a MIXED procedure was used considering the HS, LS and LS × HS as explanatory variables in the statistical model.Results showed that the studied frequency peaks had a significant relationship with the gland’s health status. Results also explained how the milk EC signals’ pattern change in case of NH glands. In fact, it is characterized by slower fluctuations (due to the lower frequencies of the peaks and by an irregular trend (due to the higher amplitudes of all the main frequency peaks. Therefore, these frequency peaks could be used as new indexes to improve the performances of algorithms based on multivariate models which evaluate the health status of dairy goats through the use of gland milk EC sensors.
12. Evaluation of the Fourier Frequency Spectrum Peaks of Milk Electrical Conductivity Signals as Indexes to Monitor the Dairy Goats’ Health Status by On-Line Sensors
Science.gov (United States)
Zaninelli, Mauro; Agazzi, Alessandro; Costa, Annamaria; Tangorra, Francesco Maria; Rossi, Luciana; Savoini, Giovanni
2015-01-01
The aim of this study is a further characterization of the electrical conductivity (EC) signal of goat milk, acquired on-line by EC sensors, to identify new indexes representative of the EC variations that can be observed during milking, when considering not healthy (NH) glands. Two foremilk gland samples from 42 Saanen goats, were collected for three consecutive weeks and for three different lactation stages (LS: 0–60 Days In Milking (DIM); 61–120 DIM; 121–180 DIM), for a total amount of 1512 samples. Bacteriological analyses and somatic cells counts (SCC) were used to define the health status of the glands. With negative bacteriological analyses and SCC 1,000,000 cells/mL, glands were classified as NH. For each milk EC signal, acquired on-line and for each gland considered, the Fourier frequency spectrum of the signal was calculated and three representative frequency peaks were identified. To evaluate data acquired a MIXED procedure was used considering the HS, LS and LS × HS as explanatory variables in the statistical model.Results showed that the studied frequency peaks had a significant relationship with the gland’s health status. Results also explained how the milk EC signals’ pattern change in case of NH glands. In fact, it is characterized by slower fluctuations (due to the lower frequencies of the peaks) and by an irregular trend (due to the higher amplitudes of all the main frequency peaks). Therefore, these frequency peaks could be used as new indexes to improve the performances of algorithms based on multivariate models which evaluate the health status of dairy goats through the use of gland milk EC sensors. PMID:26307993
13. Relação entre a infusão contínua de dexmedetomidina e a fração expirada de sevoflurano monitorizada pelo índice bispectral
OpenAIRE
Magalhães Edno; Govêia Cátia Sousa; Ladeira Luís Cláudio de Araújo; Espíndola Beatriz Vieira
2004-01-01
JUSTIFICATIVA E OBJETIVOS: A associação de agentes venosos à anestesia geral inalatória proporciona melhor qualidade de analgesia e hipnose. A dexmedetomidina é um agonista específico alfa2-adrenérgico com estas características e reconhecida por proporcionar estabilidade hemodinâmica. O objetivo do estudo foi avaliar o efeito da infusão contínua de dexmedetomidina na fração expirada de sevoflurano (FEsevo) em anestesia geral, monitorizada pela análise bispectral do EEG (BIS). MÉTODO: Estudou-...
14. 某发电集团生产运营监测指标体系构建方法研究%Monitoring Index System Construction Method Research of Production and Operation for Power Group
Institute of Scientific and Technical Information of China (English)
刘才华; 杨德胜; 赵志国; 胡传胜
2015-01-01
To implement the company strategy,the application of the public service values and the Balanced Scorecard theory,to build the company a unified,complete,can be quantified, comparable to the production and operation of monitoring index system,Through the construction of the company's production and operation monitoring index system,timely,comprehensive,accurately grasp the company's operating performance,management performance and core resources, discovery,development requires coordination with the company to resolve the problem of incompatibility, carry out multi-dimensional analysis and depth of cross business,cross level mining.It will effectively promote the transformation of company management,realize resource integration,to enhance the company's operation level,to ensure the steady development of the company.%为贯彻落实公司宏伟战略目标，本文运用应用公共服务价值和平衡计分卡理论，构建公司统一的、完整的、可量化、可比的生产运营监测指标体系，通过建设公司生产运营监测指标体系，能够及时、全面、准确地掌握公司经营业绩、管理绩效与核心资源状况，发现、协调解决与公司发展要求不相适应的问题，开展跨业务、跨层级的多维分析和深度数据挖掘。它的建成将有效促进公司管理方式变革，实现公司资源整合，提升公司运营水平，确保公司稳健发展。
15. The tree BVOC index.
Science.gov (United States)
Simpson, J R; McPherson, E G
2011-01-01
Urban trees can produce a number of benefits, among them improved air quality. Biogenic volatile organic compounds (BVOCs) emitted by some species are ozone precursors. Modifying future tree planting to favor lower-emitting species can reduce these emissions and aid air management districts in meeting federally mandated emissions reductions for these compounds. Changes in BVOC emissions are calculated as the result of transitioning to a lower-emitting species mix in future planting. A simplified method for calculating the emissions reduction and a Tree BVOC index based on the calculated reduction is described. An example illustrates the use of the index as a tool for implementation and monitoring of a tree program designed to reduce BVOC emissions as a control measure being developed as part of the State Implementation Plan (SIP) for the Sacramento Federal Nonattainment Area. PMID:21435760
16. Evidences from long-term monitoring of Italian forests. Tree radial growth as response index to disturbances and its relations with the stand structure
Directory of Open Access Journals (Sweden)
Bertini G
2013-09-01
Full Text Available The paper deals with the work undertaken since 1995 within the national level II network framed into the ICP-Forests ICP-IM programme. A synthesis of results from tree growth monitoring and relationships with stand structure and related parameters, are reported. Current changes in the growth medium, i.e. physics and chemistry of atmosphere and soil, (increase of average air temperature, rainfall shortage and drought, CO2 enrichment, ozone level, nitrogen fertilization, sulphate deposition drive today the soil-tree-atmosphere relationships. The overall result of these concurrent and counteracting factors is recorded along each growing seasons by radial stem growth, it providing a sensitive response. A few occurrences of disturbances to growth at regional and at case-study level, likely due to climate deviations, are discussed. Seasonal fluctuations and anomalous or extreme events are, as a matter of fact, the major evidences over the last decade. The heat wave 2003 is the main case occurred over a large part of Europe. Growth rate 2000-04 compared with 1997-2000, showed reductions up to 50% on plots located within the Southern continental border of the heat wave. These occurred more specifically at low elevations and for pre-determined early growth species (beech and oaks. Over the following time-window 2005-09, a significant growth decrease was vice versa detected within the coniferous spruce forests located at medium-high elevation in the Alps, where repeated seasonal anomalies both in air temperature and rainfall were recorded over the same time-span. The heavy effect of climate disturbance at a local scale is finally examined where two oak species with different auto-ecology grow together at the same site. Reasons why and awaited goals from protocols’ updating and the more intensive surveys applied to core-areas in 2009-10 under LIFE+FutMon, are reported. Perspectives at short to medium term of monitoring programme at national and European
17. Non-invasive imaging to monitor lupus nephritis and neuropsychiatric systemic lupus erythematosus [v1; ref status: indexed, http://f1000r.es/5gh
Directory of Open Access Journals (Sweden)
Joshua Thurman
2015-06-01
Full Text Available Systemic lupus erythematosus (SLE is an autoimmune disease that can affect multiple different organs, including the kidneys and central nervous system (CNS. Conventional radiological examinations in SLE patients include volumetric/ anatomical computed tomography (CT, magnetic resonance imaging (MRI and ultrasound (US. The utility of these modalities is limited, however, due to the complexity of the disease. Furthermore, CT and MRI contrast agents are contraindicated in patients with renal impairment. Various radiologic methods are currently being developed to improve disease characterization in patients with SLE beyond simple anatomical endpoints. Physiological non-contrast MRI protocols have been developed to assess tissue oxygenation, glomerular filtration, renal perfusion, interstitial diffusion, and inflammation-driven fibrosis in lupus nephritis (LN patients. For neurological symptoms, vessel size imaging (VSI, an MRI approach utilizing T2-relaxing iron oxide nanoparticles has shown promise as a diagnostic tool. Molecular imaging probes (mostly for MRI and nuclear medicine imaging have also been developed for diagnosing SLE with high sensitivity, and for monitoring disease activity. This paper reviews the challenges in evaluating disease activity in patients with LN and neuropsychiatric systemic lupus erythematosus (NPSLE. We describe novel MRI and positron-emission tomography (PET molecular imaging protocols using targeted iron oxide nanoparticles and radioactive ligands, respectively, for detection of SLE-associated inflammation.
18. Multi-Temporal Crop Surface Models Combined with the RGB Vegetation Index from Uav-Based Images for Forage Monitoring in Grassland
Science.gov (United States)
Possoch, M.; Bieker, S.; Hoffmeister, D.; Bolten, A.; Schellberg, J.; Bareth, G.
2016-06-01
Remote sensing of crop biomass is important in regard to precision agriculture, which aims to improve nutrient use efficiency and to develop better stress and disease management. In this study, multi-temporal crop surface models (CSMs) were generated from UAV-based dense imaging in order to derive plant height distribution and to determine forage mass. The low-cost UAV-based RGB imaging was carried out in a grassland experiment at the University of Bonn, Germany, in summer 2015. The test site comprised three consecutive growths including six different nitrogen fertilizer levels and three replicates, in sum 324 plots with a size of 1.5×1.5 m. Each growth consisted of six harvesting dates. RGB-images and biomass samples were taken at twelve dates nearly biweekly within two growths between June and September 2015. Images were taken with a DJI Phantom 2 in combination of a 2D Zenmuse gimbal and a GoPro Hero 3 (black edition). Overlapping images were captured in 13 to 16 m and overview images in approximately 60 m height at 2 frames per second. The RGB vegetation index (RGBVI) was calculated as the normalized difference of the squared green reflectance and the product of blue and red reflectance from the non-calibrated images. The post processing was done with Agisoft PhotoScan Professional (SfM-based) and Esri ArcGIS. 14 ground control points (GCPs) were located in the field, distinguished by 30 cm × 30 cm markers and measured with a RTK-GPS (HiPer Pro Topcon) with 0.01 m horizontal and vertical precision. The errors of the spatial resolution in x-, y-, z-direction were in a scale of 3-4 cm. From each survey, also one distortion corrected image was georeferenced by the same GCPs and used for the RGBVI calculation. The results have been used to analyse and evaluate the relationship between estimated plant height derived with this low-cost UAV-system and forage mass. Results indicate that the plant height seems to be a suitable indicator for forage mass. There is a
19. New Index for Soil Moisture Monitoring Based on ΔTs-Albedo Spectral Information%基于△Ts-Albedo光谱信息的土壤水分监测新指数研究
Institute of Scientific and Technical Information of China (English)
姚云军; 秦其明; 赵少华; 沈心一; 随欣欣
2011-01-01
20. Quality Control Index Framework of Environmental Water Quality Auto-monitoring System%环境水质自动监测系统质量控制指标框架
Institute of Scientific and Technical Information of China (English)
史箴; 段慧; 张丹; 杨朋
2013-01-01
Tnis paper reviews the establishment and operation status of the water quality automatic monitoring system. From the view point of whole process quality control, it puts forward the quality assurance measures of the construction of water quality automatic monitoring system such as sites selection, the unit design of water production and water distribution, performance of the automatic monitoring equipment, environment and safety protection for the station buildings, personnel and regulation establishment as well as the quality control index framework in the process of operation such as licensed personnel, operation and maintenance, calibration and performance testing of instruments, comparison experiment, check and audit of data quality.%本文回顾了水质自动监测系统质量管理制度的建立和运行现状,从全程序质量管理的角度,提出了站点选择地址、采水和配水单元设计、自动监测仪器性能、站房环境和安全保护、人员配备和制度建设等水质自动监测系统建设过程中的质量保证措施,以及人员持证上岗、运行维护、仪器校准和性能测试、比对实验、数据质量检查与审棱等运行过程中的质量控制指标框架.
1. Cloud phase identification based on brightness temperatures provided by the bi-spectral IR Camera of JEM-EUSO Mission
Directory of Open Access Journals (Sweden)
de Castro Antonio J.
2015-01-01
Full Text Available Cloud information is extremely important to correctly interpret the JEM-EUSO telescope data since UV radiation coming from the Extensive Air Shower can be partially absorbed or reflected by clouds. In order to observe the atmosphere and clouds in the field of view of the UV telescope the JEM-EUSO system will include an Atmospheric Monitoring System, which consists of a LIDAR and an IR Camera. Until now several radiative algorithms have been developed to retrieve the cloud top temperature from the brightness temperatures (BT that the IR Camera will provide in two IR spectral bands (10.8 and 12 μm. In some cases the performance of the algorithms depends on cloud phase: water, ice or mixed. For this reason the identification of the cloud phase is valuable information for the correct interpretation of the cloud temperatures retrieved by radiative algorithms. Some previous proposals based on brightness temperature differences (BTD have revealed that it is not easy to determine unambiguously the phase. In this work we present criteria to retrieve the cloud phase based on IR Camera BTDs. It has been checked with MODIS images to evaluate the possibilities to identify cloud phase with the JEM-EUSO IR Camera.
2. 普通男大学生有氧能力监测指标研究%The Research on Aerobic Capacity’s Monitoring Indexes of Ordinary Male Undergraduates
Institute of Scientific and Technical Information of China (English)
陈飞渡; 常永玲; 汤长发
2014-01-01
本文目的旨在筛选我国大学生体质有氧能力监测指标，为其健康测试指标体系提供理论依据。方法：将实验对象分为建模组和评估组，以VO2max和AT作为效标，将建模组1000m跑、12min跑、20m往返跑、台阶试验指数的测试结果与效标进行相关性分析，筛选指标；而后以筛选的指标为自变量，VO2max为因变量，建立预测 VO2max的回归模型进行线性回归分析，再通过评估组对VO2max预测模型进行实效性评估，以确定指标的优良性。结果：（1）12min跑和20m往返跑不仅与VO2max之间呈高度相关性，而且与VT之间也表现出较高的相关性；1000m跑与VO2max和VT 之间相关性很低；台阶试验指数与 VO2max和 VT 之间均无相关性。（2）以12min跑、20m往返跑建立预测VO2max的回归模型拟合优度均较高，预测效果通过相关性检验和配对t检验显示实效性均较好。结论：（1）12min跑不仅是一项能有效评价大学生有氧能力的指标，而且还是一种科学的有氧健身方式；（2）20m往返跑也可以有效地反映大学生有氧能力水平；（3）1000m跑和台阶试验指数不适合作为评定大学生有氧能力的指标。%Purpose:This essay aims at screening the monitoring indexes of college students’ aerobic capacity to provide a theoretical basis for the reconstruction of the health assessment index system .Methods :The experimental subjects were divided into modeling group and assessment group .VO2max and AT as a calibration ,analyze the correlation of the calibration and test result of modeling group’s 1000m running ,12min running ,20m shuttle running ,and step test ,and then screen indexes .Then the screened indexes as independent variable and VO2max as the dependent variable ,establish a model to predict VO2max ’s regression and analyze its linear re‐gression .Conduct an effectiveness assessment of the VO2max prediction model to identify the
3. Vegetation Drought Response Index: 2010-Present
Data.gov (United States)
U.S. Geological Survey, Department of the Interior — VegDRI, short for Vegetation Drought Response Index, is a drought-monitoring tool developed by scientists at EROS in collaboration with the National Drought...
4. A Framework Based on 2-D Taylor Expansion for Quantifying the Impacts of Subpixel Reflectance Variance and Covariance on Cloud Optical Thickness and Effective Radius Retrievals Based on the Bispectral Method
Science.gov (United States)
Zhang, Z.; Werner, F.; Cho, H.-M.; Wind, G.; Platnick, S.; Ackerman, A. S.; Di Girolamo, L.; Marshak, A.; Meyer, K.
2016-01-01
The bispectral method retrieves cloud optical thickness (t) and cloud droplet effective radius (re) simultaneously from a pair of cloud reflectance observations, one in a visible or near-infrared (VIS/NIR) band and the other in a shortwave infrared (SWIR) band. A cloudy pixel is usually assumed to be horizontally homogeneous in the retrieval. Ignoring subpixel variations of cloud reflectances can lead to a significant bias in the retrieved t and re. In the literature, the retrievals of t and re are often assumed to be independent and considered separately when investigating the impact of subpixel cloud reflectance variations on the bispectral method. As a result, the impact on t is contributed only by the subpixel variation of VIS/NIR band reflectance and the impact on re only by the subpixel variation of SWIR band reflectance. In our new framework, we use the Taylor expansion of a two-variable function to understand and quantify the impacts of subpixel variances of VIS/NIR and SWIR cloud reflectances and their covariance on the t and re retrievals. This framework takes into account the fact that the retrievals are determined by both VIS/NIR and SWIR band observations in a mutually dependent way. In comparison with previous studies, it provides a more comprehensive understanding of how subpixel cloud reflectance variations impact the t and re retrievals based on the bispectral method. In particular, our framework provides a mathematical explanation of how the subpixel variation in VIS/NIR band influences the re retrieval and why it can sometimes outweigh the influence of variations in the SWIR band and dominate the error in re retrievals, leading to a potential contribution of positive bias to the re retrieval. We test our framework using synthetic cloud fields from a large-eddy simulation and real observations from Moderate Resolution Imaging Spectroradiometer. The predicted results based on our framework agree very well with the numerical simulations. Our
5. EJSCREEN Indexes 2015 Public
Data.gov (United States)
U.S. Environmental Protection Agency — There is an EJ Index for each environmental indicator. There are eight EJ Indexes in EJSCREEN reflecting the 8 environmental indicators. The EJ Index names are:...
6. EJSCREEN Indexes 2015 Internal
Data.gov (United States)
U.S. Environmental Protection Agency — There is an EJ Index for each environmental indicator. There are 12 EJ Indexes in EJSCREEN reflecting the 12 environmental indicators. The EJ Index names are:...
7. Analysis in indexing
DEFF Research Database (Denmark)
Mai, Jens Erik
2005-01-01
The paper discusses the notion of steps in indexing and reveals that the document-centered approach to indexing is prevalent and argues that the document-centered approach is problematic because it blocks out context-dependent factors in the indexing process. A domain-centered approach to indexin...... explain the indexing process and suggests that the domain-centered approach offers a guide for indexers that can help them manage the complexity of indexing. © 2004 Elsevier Ltd. All rights reserved....
8. The training of rapid mobile ability to special policeman under the monitor of the index of blood lactate%特警快速机动能力训练血乳酸监控
Institute of Scientific and Technical Information of China (English)
张敏; 冯凯琳; 谭思洁
2012-01-01
[目的]研究设计针对提高特警快速机动能力的训练间歇模式和训练方案,为部队科学训练提供依据.[方法]男性特警队员40名分为实验组(20名),对照组(20名).依据血乳酸浓度,筛选设计训练组合间歇模式和训练方案,实验组采用实验方案组织实施速度训练,对照组按常规方法训练,持续训练8周.[结果]极限强度30、60、100 m反复跑及其它相应训练间歇时间2～6 min以上,可避免过量乳酸堆积;实验组训练后快速运动能力测试指标:30 m、100m、立定跳远、十字跳显著好于对照组(P＜0.05).[结论]应用血乳酸指标监控部队速度训练具有可行性和实用价值,可为部队快速机动能力训练方案的设计提供依据.测定速度训练后血乳酸值可评价特警队员的ATP-CP供能能力.采用针对性方法对能量供应系统实施合理的刺激是提高部队快速机动能力的关键.%[Objective] To improve the training interval model and project of rapid mobile ability to special policeman, which will be benefit for scientific training in the military. [ Methods ] 40 male special policemen will be divided into two groups. 20 were included in experimental group, and 20 were in the control group. According to the concentration of blood lactate, we designed the training interval model and project. Experimental scheme was adopted in the experimental group, the training in control group was as usual. It lasted for 8 weeks. [Results] Suppose the interval of running with 30m,60m,100m ultimate strength and other training is above 2-6min , excessive accumulation of lactate will be avoided. The index of rapid mobile ability in the experimental group is better than that of control group after performing 30m,100m,long jump and cross jump . (P< 0.05). [Conclusions]It is feasible and valuable to monitor military speed training applied by the index of blood lactate, which will support the project of rapid mobile ability. The value of
9. How indexes have changed
International Nuclear Information System (INIS)
The accompanying table compares refinery construction and operating wages monthly for the years 1990 and 1991. The Nelson-Farrar refinery construction cost indexes are inflation indexes, while the operating indexes incorporate a productivity which shows improvement with experience and the increasing size of operations. The refinery construction wage indexes in the table show a steady advance over the 2-year period. Common labor indexes moved up faster than skilled indexes. Refinery operating wages showed a steady increase, while productivities averaged higher near the end of the period. Net result is that labor costs remained steady for the period
10. Reactivity monitoring in ADS systems
International Nuclear Information System (INIS)
Monitoring reactivity in an ADS should be performed on-line with a simple, accurate and robust technique. Within the range of experimental reactor techniques, no single technique can be selected which meet these requirements. Therefore a combination of different techniques has to be chosen in a way that various off-line techniques serve as a calibration for the on-line measurement technique. As an on-line measurement technique, the current/flux reactivity indicator is the most simple and robust solution. It is based on the fact that in a subcritical multiplying medium with a driving source the flux level is proportional to the driving source intensity, hence the beam current, and the reactivity level. However, since the proportionality constant depends on a number of core dependent parameters and detector characteristics, this current-to-flux indicator has to be calibrated on a regular basis. For this calibration, one could benefit from the occurrence of accelerator beam trips to determine the reactivity level in dollars by means of a prompt jump analysis of the flux level change. Hence, the prompt jump reactivity indicator could act as a first calibration tool of the current-to-flux indicator. Since the prompt jump indicator still relies on the value for the effective delayed neutron fraction to determine reactivity level, complementary techniques have to be used to obtain a more accurate determination of the reactivity. Techniques based on reactor noise methods such as RAPJA technique which is combination of the Rossi-alpha method and Prompt jump analysis can be used in this respect. In the future the bi-spectral ratio from the Cf - source driven noise analysis could be used for this purpose. (author)
11. 利用时序合成孔径雷达数据监测水稻叶面积指数%Monitoring rice leaf area index using time-series SAR data
Institute of Scientific and Technical Information of China (English)
张晓倩; 郭琳; 马尚杰; 赵占营; 裴志远
2014-01-01
Rice is one of the most important food crops in China, so timely obtaining accurate rice growth information in regional scale is highly significant for crop management and decision making. However, there are plenty of rain and dense cloud cover in rice growth season, that makes it difficult to monitor rice paddy information by optical remote sensing data. It is an accepted fact that Synthetic Aperture Radar (SAR) data is a suitable alternative for crop monitoring in cloud-prone and raining area. In this paper, we investigated the potential of Radarsat-2 SAR data for rice paddy growth monitoring at regional scale. Four C-band SAR backscattering coefficients (VH, VV, HH, HV) and HH/VV ratio backscattering coefficient were employed for setting up the relationship with leaf area index (LAI) in rice growing season. The test site located in Leizhou (20°52′N, 110°05′E), Guangdong province. Four Radarsat-2 products in fine quad polarization mode were acquired during the critical rice growth stage. In situ measurement in year 2013 was also made concurrently with the satellite pass. 25 plots were selected for measuring the rice growth parameters, such as LAI, plant height, sowing date, etc. The backscattering coefficients with multi-incidence angle were extracted from multi-temporal SAR images and then normalized to same angle. Firstly, the study analyzed the temporal behavior of microwave backscattering coefficients (VH, VV, HH, HV, HH/VV) and LAI in rice growth season. Secondly, correlation analyses between the backscattering coefficients in different polarization and LAI were also carried out in vegetative stage, reproductive stage and whole growth period respectively, then picking the polarization and growth stage corresponding with high correlation coefficient which was above 0.8 to build water cloud model and evaluate the performance of each model. Finally, based on the previous result, the LAI distribution map in time domain was generated using the best model of
12. Ant-App-DB: a smart solution for monitoring arthropods activities, experimental data management and solar calculations without GPS in behavioral field studies [v2; ref status: indexed, http://f1000r.es/59a
OpenAIRE
Zeeshan Ahmed; Saman Zeeshan; Pauline Fleischmann; Wolfgang Rössler; Thomas Dandekar
2015-01-01
Field studies on arthropod ecology and behaviour require simple and robust monitoring tools, preferably with direct access to an integrated database. We have developed and here present a database tool allowing smart-phone based monitoring of arthropods. This smart phone application provides an easy solution to collect, manage and process the data in the field which has been a very difficult task for field biologists using traditional methods. To monitor our example species, the desert ant Cat...
13. A Global Grassland Drought Index (GDI) Product: Algorithm and Validation
OpenAIRE
Binbin He; Zhanmang Liao; Xingwen Quan; Xing Li; Junjie Hu
2015-01-01
Existing drought indices have been widely used to monitor meteorological drought and agricultural drought; however, few of them are focus on drought monitoring for grassland regions. This study presented a new drought index, the Grassland Drought Index (GDI), for monitoring drought conditions in global grassland regions. These regions are vital for the environment and human society but susceptible to drought. The GDI was constructed based on three measures of water content: precipitation, soi...
14. Human Use Index
Data.gov (United States)
U.S. Environmental Protection Agency — Human land uses may have major impacts on ecosystems, affecting biodiversity, habitat, air and water quality. The human use index (also known as U-index) is the...
15. Glycemic Index and Diabetes
Science.gov (United States)
... A A Listen En Español Glycemic Index and Diabetes The glycemic index, or GI, measures how a ... 08-book-sabores-de-cuba.html More from diabetes.org Shopdiabetes.org: Take the Guesswork out of ...
16. Master Veteran Index (MVI)
Data.gov (United States)
Department of Veterans Affairs — As of June 28, 2010, the Master Veteran Index (MVI) database based on the enhanced Master Patient Index (MPI) is the authoritative identity service within the VA,...
17. The Glycemic Index
OpenAIRE
Williams, Pauline; Stubbs, Wendy
2003-01-01
The glycemic index is a ranking of carbohydrate containing foods. Foods are ranked according to their immediate effect on blood sugar levels. The higher a food raises blood sugar, the higher its glycemic index
18. Body mass index
Science.gov (United States)
... page: //medlineplus.gov/ency/article/007196.htm Body mass index To use the sharing features on this ... your height is to figure out your body mass index (BMI). You and your health care provider ...
19. UV Index Widget
Data.gov (United States)
U.S. Environmental Protection Agency — The UV Index Widget displays the ultraviolet (UV) Index providing a daily forecast of the expected risk of overexposure to the sun for a user-specified area of...
20. Human Use Index (Future)
Data.gov (United States)
U.S. Environmental Protection Agency — Human land uses may have major impacts on ecosystems, affecting biodiversity, habitat, air and water quality. The human use index (also known as U-index) is the...
1. American Samoa ESI: INDEX (Index Polygons)
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all the hardcopy cartographic products produced as part of the Environmental Sensitivity Index...
2. Performance Indexes: Similarities and Differences
Directory of Open Access Journals (Sweden)
2013-06-01
Full Text Available The investor of today is more rigorous on monitoring a financial assets portfolio. He no longer thinks only in terms of the expected return (one dimension, but in terms of risk-return (two dimensions. Thus new perception is more complex, since the risk measurement can vary according to anyone’s perception; some use the standard deviation for that, others disagree with this measure by proposing others. In addition to this difficulty, there is the problem of how to consider these two dimensions. The objective of this essay is to study the main performance indexes through an empirical study in order to verify the differences and similarities for some of the selected assets. One performance index proposed in Caldeira (2005 shall be included in this analysis.
3. Optimal wavelengths obtained from laws analogous to the Wien's law for monospectral and bispectral methods, and general methodology for multispectral temperature measurements taking into account global transfer function including non-uniform emissivity of surfaces
Science.gov (United States)
Rodiet, Christophe; Remy, Benjamin; Degiovanni, Alain
2016-05-01
In this paper, it is shown how to select the optimal wavelengths minimizing the relative error and the standard deviation of the temperature. Furthermore, it is shown that the optimal wavelengths in mono-spectral and bi-spectral methods (for a Planck's law) can be determined by laws analogous to the displacement Wien's law. The simplicity of these laws can thus allow real-time selection of optimal wavelengths for a control/optimization of industrial processes, for example. A more general methodology to obtain the optimal wavelengths selection in a multi-spectral method (taking into account the spectral variations of the global transfer function including the emissivity variations) for temperature measurement of surfaces exhibiting non-uniform emissivity, is also presented. This latter can then find an interest in glass furnaces temperature measurement with spatiotemporal non-uniformities of emissivity, the control of biomass pyrolysis, the surface temperature measurement of buildings or heating devices, for example. The goal consists of minimizing the standard deviation of the estimated temperature (optimal design experiment). For the multi-spectral method, two cases will be treated: optimal global and optimal constrained wavelengths selection (to the spectral range of the detector, for example). The estimated temperature results obtained by different models and for different number of parameters and wavelengths are compared. These different points are treated from theoretical, numerical and experimental points of view.
4. Cirrus cloud optical and microphysical property retrievals from eMAS during SEAC4RS using bi-spectral reflectance measurements within the 1.88 µm water vapor absorption band
Science.gov (United States)
Meyer, Kerry; Platnick, Steven; Arnold, G. Thomas; Holz, Robert E.; Veglio, Paolo; Yorks, John; Wang, Chenxi
2016-04-01
Previous bi-spectral imager retrievals of cloud optical thickness (COT) and effective particle radius (CER) based on the Nakajima and King (1990) approach, such as those of the operational MODIS cloud optical property retrieval product (MOD06), have typically paired a non-absorbing visible or near-infrared wavelength, sensitive to COT, with an absorbing shortwave or mid-wave infrared wavelength sensitive to CER. However, in practice it is only necessary to select two spectral channels that exhibit a strong contrast in cloud particle absorption. Here it is shown, using eMAS observations obtained during NASA's SEAC4RS field campaign, that selecting two absorbing wavelength channels within the broader 1.88 µm water vapor absorption band, namely the 1.83 and 1.93 µm channels that have sufficient differences in ice crystal single scattering albedo, can yield COT and CER retrievals for thin to moderately thick single-layer cirrus that are reasonably consistent with other solar and IR imager-based and lidar-based retrievals. A distinct advantage of this channel selection for cirrus cloud retrievals is that the below-cloud water vapor absorption minimizes the surface contribution to measured cloudy top-of-atmosphere reflectance, in particular compared to the solar window channels used in heritage retrievals such as MOD06. This reduces retrieval uncertainty resulting from errors in the surface reflectance assumption and reduces the frequency of retrieval failures for thin cirrus clouds.
5. The Glycemic Index
OpenAIRE
Williams, Pauline
2004-01-01
The glycemic index is a ranking of carbohydrate containing foods. Foods are ranked according to their immediate effect on blood sugar levels. The higher a f ood raises blood sugar, the higher its glycemic index. Scientists published the first index in 1981 when they were researching diet therapy for diabetes. This first list contained 51 foods, and the list has continued to expand, with the most recent official list containing 750 foods. Fruits, grains, dairy products, some vegetables, pastas...
6. Diet quality assessment indexes
OpenAIRE
Kênia Mara Baiocchi de Carvalho; Eliane Said Dutra; Nathalia Pizato; Nádia Dias Gruezo; Marina Kiyomi Ito
2014-01-01
Various indices and scores based on admittedly healthy dietary patterns or food guides for the general population, or aiming at the prevention of diet-related diseases have been developed to assess diet quality. The four indices preferred by most studies are: the Diet Quality Index; the Healthy Eating Index; the Mediterranean Diet Score; and the Overall Nutritional Quality Index. Other instruments based on these indices have been developed and the words 'adapted', 'revised', or 'new version I...
7. Supplement: Commodity Index Report
Data.gov (United States)
Commodity Futures Trading Commission — Shows index traders in selected agricultural markets. These traders are drawn from the noncommercial and commercial categories. The noncommercial category includes...
8. EJSCREEN Supplementary Indexes 2015 Public
Data.gov (United States)
U.S. Environmental Protection Agency — There are 40 supplementary EJSCREEN indexes that are divided into 5 categories: EJ Index with supplementary demographic index, Supplementary EJ Index 1 with...
9. EJSCREEN Supplementary Indexes 2015 Internal
Data.gov (United States)
U.S. Environmental Protection Agency — There are 60 supplementary EJ Indexes in EJSCREEN that are divided into 5 categories: EJ Index with supplementary demographic index, Supplementary EJ Index 1 with...
10. Arterial stiffness, as monitored by cardio–ankle vascular index, is affected by obstructive sleep apnea, blood glucose control, and body weight – a case with 8 years follow up
OpenAIRE
Shimizu, Kazuhiro; Yamamoto, Tomoyuki; Shirai, Kohji
2016-01-01
Kazuhiro Shimizu,1 Tomoyuki Yamamoto,2,3 Kohji Shirai2,4 1Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan; 2Department of Vascular Function, Toho University Sakura Medical Center, Chiba, Japan; 3Biological Information Analysis Section, Fukuda Denshi Co., Ltd., Tokyo, Japan; 4Department of Internal Medicine, Mihama Hospital, Chiba, Japan Abstract: The cardio–ankle vascular index (CAVI) is an indicator of arterial stiffness from the heart ...
11. Watts Poverty Index
OpenAIRE
SAISANA Michaela
2014-01-01
The Watts poverty index is the first distribution-sensitive poverty measure, and it was proposed in 1964 by Harold W. Watts (1964). The index is computed by dividing the poverty line by income, taking logs, and taking the sum over the poor.
12. ParkIndex
DEFF Research Database (Denmark)
Kaczynski, Andrew T; Schipperijn, Jasper; Hipp, J Aaron; Besenyi, Gina M; Stanis, Sonja A Wilhelm; Hughey, S Morgan; Wilcox, Sara
2016-01-01
A lack of comprehensive and standardized metrics for measuring park exposure limits park-related research and health promotion efforts. This study aimed to develop and demonstrate an empirically-derived and spatially-represented index of park access (ParkIndex) that would allow researchers, plann...... significance for researchers and professionals in diverse disciplines....
13. EMMSE Media Index.
Science.gov (United States)
Hewitt, Clifford A., Comp.; McKinstry, Herbert A., Comp.
This index provides a topical taxonomy of media which have been selected for their relevance in the teaching of materials science and engineering. The index is keyed to a matrix which matches topical and/or class material with six classifications of media: print, 16mm film, super 8 film, slide/tape, videotape, and other (including interactive…
14. Global Ecosystem Restoration Index
DEFF Research Database (Denmark)
Fernandez, Miguel; Garcia, Monica; Fernandez, Nestor
2015-01-01
The Global ecosystem restoration index (GERI) is a composite index that integrates structural and functional aspects of the ecosystem restoration process. These elements are evaluated through a window that looks into a baseline for degraded ecosystems with the objective to assess restoration...
15. Model and Calculation of Container Port Logistics Enterprises Efficiency Indexes
Directory of Open Access Journals (Sweden)
Xiao Hong
2013-04-01
Full Text Available The throughput of China’s container port is growing fast, but the earnings of inland port enterprises are not so good. Firstly ,the initial efficiency evaluation indexes of port logistics are reduced and screened by rough set model, and then logistics performance indexes weight are assigned by the rough totalitarian calculation method. As well, the rank of the indexes and the important indexes are picked up by combining with ABC management method. So the port logistics enterprises can monitor the key indexes to reduce cost and improve the efficiency of the logistics operations.
16. Climate Prediction Center (CPC)Oceanic Nino Index
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — The Oceanic Nino Index (ONI) is one of the primary indices used to monitor the El Nino-Southern Oscillation (ENSO). The ONI is calculated by averaging sea surface...
17. Ant-App-DB: a smart solution for monitoring arthropods activities, experimental data management and solar calculations without GPS in behavioral field studies [v3; ref status: indexed, http://f1000r.es/5dm
Directory of Open Access Journals (Sweden)
Zeeshan Ahmed
2015-05-01
Full Text Available Field studies on arthropod ecology and behaviour require simple and robust monitoring tools, preferably with direct access to an integrated database. We have developed and here present a database tool allowing smart-phone based monitoring of arthropods. This smart phone application provides an easy solution to collect, manage and process the data in the field which has been a very difficult task for field biologists using traditional methods. To monitor our example species, the desert ant Cataglyphis fortis, we considered behavior, nest search runs, feeding habits and path segmentations including detailed information on solar position and azimuth calculation, ant orientation and time of day. For this we established a user friendly database system integrating the Ant-App-DB with a smart phone and tablet application, combining experimental data manipulation with data management and providing solar position and timing estimations without any GPS or GIS system. Moreover, the new desktop application Dataplus allows efficient data extraction and conversion from smart phone application to personal computers, for further ecological data analysis and sharing. All features, software code and database as well as Dataplus application are made available completely free of charge and sufficiently generic to be easily adapted to other field monitoring studies on arthropods or other migratory organisms. The software applications Ant-App-DB and Dataplus described here are developed using the Android SDK, Java, XML, C# and SQLite Database.
18. Ant-App-DB: a smart solution for monitoring arthropods activities, experimental data management and solar calculations without GPS in behavioral field studies [v2; ref status: indexed, http://f1000r.es/59a
Directory of Open Access Journals (Sweden)
Zeeshan Ahmed
2015-04-01
Full Text Available Field studies on arthropod ecology and behaviour require simple and robust monitoring tools, preferably with direct access to an integrated database. We have developed and here present a database tool allowing smart-phone based monitoring of arthropods. This smart phone application provides an easy solution to collect, manage and process the data in the field which has been a very difficult task for field biologists using traditional methods. To monitor our example species, the desert ant Cataglyphis fortis, we considered behavior, nest search runs, feeding habits and path segmentations including detailed information on solar position and Azimuth calculation, ant orientation and time of day. For this we established a user friendly database system integrating the Ant-App-DB with a smart phone and tablet application, combining experimental data manipulation with data management and providing solar position and timing estimations without any GPS or GIS system. Moreover, the new desktop application Dataplus allows efficient data extraction and conversion from smart phone application to personal computers, for further ecological data analysis and sharing. All features, software code and database as well as Dataplus application are made available completely free of charge and sufficiently generic to be easily adapted to other field monitoring studies on arthropods or other migratory organisms. The software applications Ant-App-DB and Dataplus described here are developed using the Android SDK, Java, XML, C# and SQLite Database.
19. Ⅱ类超晶格双光谱红外探测器光谱串音的量化分析计算%Quantitative Analysis and Calculation of Spectral Crosstalk of Type Ⅱ Superlattice Bispectral Infrared Detectors
Institute of Scientific and Technical Information of China (English)
王忆锋; 余连杰; 田萦
2011-01-01
对于起降阶段的各类飞机来说,便携式导弹是主要威胁.以基于Ⅱ类超晶格双光谱红外探测器的机载导弹逼近告警(MAW)系统为应用背景,介绍了光谱串音的定义及计算方法.分别测出两个光谱通道的光谱响应曲线,容易利用MATLAB样条函数积分命令算出两条曲线交叉部分围成的面积,该面积的数值反映了器件光谱串音的大小.给出了所用MATLAB程序,该方法具有实现容易、使用快捷等特点.%The main threats for any type of aircraft are the man portable missiles during taking-off and landing.Under the application background of missile approach warning (MAW) based on type Ⅱ superlatice bispectral infrared detectors, the definition and calculation methods of spectral crosstalk were introduced.After measuring separately the spectral response curves of the two spectral channels, the area of the region bounded by the crossed sections of the two curves reflecting the amount of spectral crosstalk of the device, can be calculated easily with MATLAB spline function integration commands.The MATLAB program was listed in this paper.It is easier to implement and convenient to use.
20. The impact of cloud vertical profile on liquid water path retrieval based on the bispectral method: A theoretical study based on large-eddy simulations of shallow marine boundary layer clouds
Science.gov (United States)
Miller, Daniel J.; Zhang, Zhibo; Ackerman, Andrew S.; Platnick, Steven; Baum, Bryan A.
2016-04-01
Passive optical retrievals of cloud liquid water path (LWP), like those implemented for Moderate Resolution Imaging Spectroradiometer (MODIS), rely on cloud vertical profile assumptions to relate optical thickness (τ) and effective radius (re) retrievals to LWP. These techniques typically assume that shallow clouds are vertically homogeneous; however, an adiabatic cloud model is plausibly more realistic for shallow marine boundary layer cloud regimes. In this study a satellite retrieval simulator is used to perform MODIS-like satellite retrievals, which in turn are compared directly to the large-eddy simulation (LES) output. This satellite simulator creates a framework for rigorous quantification of the impact that vertical profile features have on LWP retrievals, and it accomplishes this while also avoiding sources of bias present in previous observational studies. The cloud vertical profiles from the LES are often more complex than either of the two standard assumptions, and the favored assumption was found to be sensitive to cloud regime (cumuliform/stratiform). Confirming previous studies, drizzle and cloud top entrainment of dry air are identified as physical features that bias LWP retrievals away from adiabatic and toward homogeneous assumptions. The mean bias induced by drizzle-influenced profiles was shown to be on the order of 5-10 g/m2. In contrast, the influence of cloud top entrainment was found to be smaller by about a factor of 2. A theoretical framework is developed to explain variability in LWP retrievals by introducing modifications to the adiabatic re profile. In addition to analyzing bispectral retrievals, we also compare results with the vertical profile sensitivity of passive polarimetric retrieval techniques.
1. Supersymmetric Berry index
CERN Document Server
Ilinskii, K N; Melezhik, V S; Ilinski, K N; Kalinin, G V; Melezhik, V V
1994-01-01
We revise the sequences of SUSY for a cyclic adiabatic evolution governed by the supersymmetric quantum mechanical Hamiltonian. The condition (supersymmetric adiabatic evolution) under which the supersymmetric reductions of Berry (nondegenerated case) or Wilczek-Zee (degenerated case) phases of superpartners are taking place is pointed out. The analogue of Witten index (supersymmetric Berry index) is determined. As the examples of suggested concept of supersymmetric adiabatic evolution the Holomorphic quantum mechanics on complex plane and Meromorphic quantum mechanics on Riemann surface are considered. The supersymmetric Berry indexes for the models are calculated.
2. Hedonic House Price Index
OpenAIRE
Säterbrink, Filip
2013-01-01
Nasdaq OMX Valueguard-KTH Housing Index (HOX) is a hedonic price index that illustrates the price development of condominiums in Sweden, and that is obtained by using regression technique. Concerns have been raised regarding the influence of the monthly fee on the index. Low fee condominiums could be more popular because of the low monthly cost, high fee condominiums tend to sell for a lower price due to the high monthly cost. As the price of a condominium rises the importance of the monthly ...
3. Tree-Indexed Processes
OpenAIRE
Pemantle, Robin
1995-01-01
This article examines a recent body of work on stochastic processes indexed by a tree. Emphasis is on the application of this new framework to existing probability models. Proofs are largely omitted, with references provided.
4. Arizona - Social Vulnerability Index
Data.gov (United States)
U.S. Environmental Protection Agency — The Social Vulnerability Index is derived from the 2000 US Census data. The fields included are percent minority, median household income, age (under 18 and over...
5. Palmer Drought Severity Index
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — PDSI from the Dai dataset. The Palmer Drought Severity Index (PDSI) is devised by Palmer (1965) to represent the severity of dry and wet spells over the U.S. based...
6. Index Futures Come Nearer
Institute of Scientific and Technical Information of China (English)
2009-01-01
Chinese investors have seen the dawn of stock index futures. The longexpected investment tool may be launched soon, but officials at the China Securities Regulatory Commission(CSRC) are working to further improve
7. National Death Index
Data.gov (United States)
U.S. Department of Health & Human Services — The National Death Index (NDI) is a centralized database of death record information on file in state vital statistics offices. Working with these state offices,...
8. Regional Snowfall Index (RSI)
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Climatic Data Center is now producing the Regional Snowfall Index (RSI) for significant snowstorms that impact the eastern two thirds of the U.S....
9. Exploring volumetrically indexed cups
Science.gov (United States)
Jones, Dustin L.
2011-03-01
This article was inspired by a set of 12 cylindrical cups, which are volumetrically indexed; that is to say, the volume of cup n is equal to n times the volume of cup 1. Various sets of volumetrically indexed cylindrical cups are explored. I demonstrate how this children's toy is ripe for mathematical investigation, with connections to geometry, algebra and differential calculus. Students with an understanding of these topics should be able to complete the analysis and related exercises contained herein.
10. Methods explained: Index numbers
OpenAIRE
Peter Goodridge
2007-01-01
Attempts to explain the subtle differences in the methodologies used to construct index numbers.Many of the statistics produced by the Office for National Statistics,particularly economic statistics, are published in the form ofindices. However, there are a number of different forms of indices and this article attempts to explain the subtle differences in themethodologies used to construct them, and also factors that feed into the choice of which type of index to use. Hypothetical examplesare...
11. Index of Financial Inclusion
OpenAIRE
Mandira Sarma
2008-01-01
The promotion of an inclusive financial system is considered a policy priority in many countries. While the importance of financial inclusion is widely recognized, the literature lacks a comprehensive measure that can be used to measure the extent of financial inclusion across economies. This paper attempts to fill this gap by proposing an index of financial inclusion (IFI). The IFI is a multi-dimensional index that captures information on various dimensions of financial inclusion in one sing...
12. Application and Nursing of Pulse Index Continuous Cardiac Output Monitoring in Patients with Post-cardiac Arrest Syndrome%脉波指示剂连续心排血量监测在心搏骤停后综合征患者中的应用与护理
Institute of Scientific and Technical Information of China (English)
陈淑兰; 刘刚; 张秋真; 陈秋恋
2011-01-01
Objective To investigate the application effect and nursing of the pulse index continuous cardiac output (PICCO) monitoring technique in patients with post-cardiac arrest syndrome (PCAS). Methods The precautions and nursing points were developed for the flowsheet of operation, cooperation for the vein catheterization and measurements. Results Of the 15 patients using the PICCO monitoring technique in early stage,no complication occurred ,except one patient died of multiple organ failure and 3 abandoned the treatment,and the rest 11 patients survived. Conclusion PCAS patients undergoing PICCO monitoring device in the early stage can efficiently assist the fluid management,maintain the vital signs of the patients,and save their lives.%目的 探讨脉波指示剂连续心排血量监测( pulse index continuous cardiac output,PICCO)在心搏骤停后综合征(postcardiac arrest syndrome,PCAS)患者中的应用效果及护理.方法 制定操作流程、置管配合、测量的注意事项和护理要点.结果 15例患者通过早期采用了PICCO监测,并采取了相应的护理措施,均未出现并发症,除了1例患者因多器官功能衰竭死亡外,3例患者放弃治疗,其余11例患者均存活.结论 对PCAS患者早期进行PICCO监测,能对患者进行更准确的血流动力学监测,可以有效协助液体管理,维持患者生命体征的稳定,挽救患者生命.
13. Exact relationships between fisher indexes and theoretical indexes
OpenAIRE
Grifell i Tatjé, Emili; Lovell, C.A. Knox
2015-01-01
In this paper we develop exact relationships between empirical Fisher indexes and their theoretical Malmquist and Konus counterparts. We begin by using implicit Malmquist price and price recovery indexes to establish exact relationships between Malmquist quantity and productivity indexes and Fisher quantity and productivity indexes. We then show that Malmquist quantity and productivity indexes and Fisher price and price recovery indexes “almost” satisfy the product test with the rele...
14. Global Monitoring
OpenAIRE
Victor Ya. Tsvetkov
2012-01-01
The article describes the technology and classification of global monitoring, shows the relationship between the global monitoring and geographic information monitoring, presents the cause-and-effect diagram of global monitoring. The paper discloses the value of the time series for global monitoring, offers a functional diagram of the global monitoring system, gives the main characteristics of global monitoring.
15. Sustainability index for Taipei
International Nuclear Information System (INIS)
Sustainability indicators are an effective means of determining whether a city is moving towards sustainable development (SD). After considering the characteristics of Taipei, Taiwan, discussions with experts, scholars and government departments and an exhaustive literature review, this study selected 51 sustainability indicators corresponding to the socio-economic characteristic of Taipei City. Such indicators should be regarded as a basis for assessing SD in Taipei City. The 51 indicators are classified into economic, social, environmental and institutional dimensions. Furthermore, statistical data is adopted to identify the trend of SD from 1994 to 2004. Moreover, the sustainability index is calculated for the four dimensions and for Taipei as a whole. Analysis results demonstrate that social and environmental indicators are moving towards SD, while economic and institutional dimensions are performing relatively poorly. However, since 2002, the economic sustainability index has gradually moved towards SD. Overall, the Taipei sustainability index indicates a gradual trend towards sustainable development during the past 11 years
16. Nutritional monitoring of wheat by using the index of nutritional balance – DRIS/ Monitoramento nutricional do trigo através do índice de balanço nutricional – DRIS
Directory of Open Access Journals (Sweden)
Cristine E. Alvarenga Carneiro
2005-06-01
17. Influência da dexmedetomidina na concentração expirada do sevoflurano: avaliação pelo índice bispectral, taxa de supressão e análise espectral da potência do eletroencefalograma Influencia de la dexmedetomidina en la concentración expirada del sevoflurano: evaluación por el índice bispectral, tasa de supresión y análisis espectral de la potencia del eletroencefalograma Influence of dexmedetomidine upon sevoflurane end-expiratory concentration: evaluation by bispectral index, suppression rate and electroencephalographic power spectral analysis
OpenAIRE
Rogean Rodrigues Nunes; Sara Lúcia Cavalcante
2002-01-01
JUSTIFICATIVA E OBJETIVOS: A dexmedetomidina, um alfa2-agonista adrenérgico, tem sido descrita como capaz de reduzir o consumo tanto de agentes venosos como inalatórios. O objetivo deste estudo foi avaliar a influência da dexmedetomidina na concentração expirada (CE) do sevoflurano, com monitorização da profundidade da anestesia. MÉTODO: Participaram do estudo 40 pacientes do sexo feminino, estado físico ASA I, submetidas à laparoscopia ginecológica sob anestesia geral mantida com sevoflurano...
18. The Index System of Spatial Poverty of Village Level to Monitor in Concentrated Contiguous Areas with Particular Difficulties%集中连片特殊困难地区村域空间贫困测度指标体系研究
Institute of Scientific and Technical Information of China (English)
刘小鹏; 苏胜亮; 王亚娟; 黄越; 赵莹
2014-01-01
在阐述多维贫困和空间贫困概念内涵及其指标基础上，提出了集中连片特殊困难地区村域空间贫困测度指标体系构建的基本原则，即强调科学性和主导性原则、重视数据的可获得性和测度的可操作性、体现减贫与反贫困的新要求、突出区域性和空间刻画能力。据此，构建了包括经济、社会、环境和政策4个维度，收入和消费、市场连通性、人口状况、学有所教、病有所医、老有所养、住有所居、劳有所得、地貌要素、自然灾害、生态安全、农业生态、粮食安全和政策的实效性共13个指标组，27个原始指标或生成指标构成的集中连片特殊困难地区村域空间贫困测度指标体系。进一步讨论了空间贫困测度指标的检验、获取方法和空间化等关键问题。%On the basis of the exposition about concept connotations and indexes between multidimensional poverty and spatial poverty, basic principles contributing to constructing index system of spatial poverty to monitor in concentrated contiguous areas with particular difficulties were put forward, which are, scientific and dominant principles, the availability of data and the operability of the measurement, embodiment of new requirements on poverty and anti-poverty, emphasis on regional characters and ability of characterizing space. Furthermore, index system of spatial poverty to monitor in concentrated contiguous areas with particular diffi-culties which is consisting of four dimensions (economy, society, environment and policy), thirteen index groups, for example, income and consumption, market connectivity, demographic situation, education, employ-ment, medical services, a sense of security, housing condition, geomorphic elements, natural hazards, ecologi-cal security, agro-ecology, food security, policy effectiveness, was constructed according to the principles above. The index system was totally comprised of twenty
19. Life quality index revisited
DEFF Research Database (Denmark)
Ditlevsen, Ove Dalager
2004-01-01
The derivation of the life quality index (LQI) is revisited for a revision. This revision takes into account the unpaid but necessary work time needed to stay alive in clean and healthy conditions to be fit for effective wealth producing work and to enjoyable free time. Dimension analysis...
20. Indexing Moving Points
DEFF Research Database (Denmark)
Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff
2003-01-01
We propose three indexing schemes for storing a set S of N points in the plane, each moving along a linear trajectory, so that any query of the following form can be answered quickly: Given a rectangle R and a real value t, report all K points of S that lie inside R at time t. We first present an...
1. Indexical Hybrid Tense Logic
DEFF Research Database (Denmark)
Blackburn, Patrick Rowan; Jørgensen, Klaus Frovin
2012-01-01
In this paper we explore the logic of now, yesterday, today and tomorrow by combining the semantic approach to indexicality pioneered by Hans Kamp [9] and refined by David Kaplan [10] with hybrid tense logic. We first introduce a special now nominal (our @now corresponds to Kamp’s original now...
2. Fiberoptic monitoring of central venous oxygen saturation (PediaSat in small children undergoing cardiac surgery: continuous is not continuous [v3; ref status: indexed, http://f1000r.es/3qt
Directory of Open Access Journals (Sweden)
Francesca G. Iodice
2014-06-01
Full Text Available Background: Monitoring of superior vena cava saturation (ScvO2 has become routine in the management of pediatric patients undergoing cardiac surgery. The objective of our study was to evaluate the correlation between continuous ScvO2 by the application of a fiber-optic oximetry catheter (PediaSat and intermittent ScvO2 by using standard blood gas measurements. These results were compared to those obtained by cerebral near infrared spectroscopy (cNIRS. Setting: Tertiary pediatric cardiac intensive care unit (PCICU. Methods and main results: A retrospective study was conducted in consecutive patients who were monitored with a 4.5 or 5.5 F PediaSat catheter into the right internal jugular vein. An in vivo calibration was performed once the patient was transferred to the PCICU and re-calibration took place every 24 hours thereafter. Each patient had a NIRS placed on the forehead. Saturations were collected every 4 hours until extubation. Ten patients with a median age of 2.2 (0.13-8.5 years and a weight of 12.4 (3.9-24 kg were enrolled. Median sampling time was 32 (19-44 hours: 64 pairs of PediaSat and ScVO2 saturations showed a poor correlation (r=0.62, 95% CI 44-75; p<0.0001 and Bland Altman analysis for repeated measures showed an average difference of 0.34 with a standard deviation of 7,9 and 95% limits of agreement from -15 to 16. Thirty-six pairs of cNIRS and ScVO2 saturations showed a fair correlation (r=0.79, 95% CI 0.60-0.89; p<0.0001 an average difference of -1.4 with a standard deviation of 6 and 95% limits of agreement from -13 to 10. Analysis of median percentage differences between PediaSat and ScvO2 saturation over time revealed that, although not statistically significant, the change in percentage saturation differences was clinically relevant after the 8th hour from calibration (from -100 to +100%. Conclusion: PediaSat catheters showed unreliable performance in our cohort. It should be further investigated whether repeating
3. Scientific Journal Indexing
Directory of Open Access Journals (Sweden)
Getulio Teixeira Batista
2007-08-01
Full Text Available It is quite impressive the visibility of online publishing compared to offline. Lawrence (2001 computed the percentage increase across 1,494 venues containing at least five offline and five online articles. Results shown an average of 336% more citations to online articles compared to offline articles published in the same venue. If articles published in the same venue are of similar quality, then they concluded that online articles are more highly cited because of their easier access. Thomson Scientific, traditionally concerned with printed journals, announced on November 28, 2005, the launch of Web Citation Index™, the multidisciplinary citation index of scholarly content from institutional and subject-based repositories (http://scientific.thomson. com/press/2005/8298416/. The Web Citation Index from the abstracting and indexing (A&I connects together pre-print articles, institutional repositories and open access (OA journals (Chillingworth, 2005. Basically all research funds are government granted funds, tax payer’s supported and therefore, results should be made freely available to the community. Free online availability facilitates access to research findings, maximizes interaction among research groups, and optimizes efforts and research funds efficiency. Therefore, Ambi-Água is committed to provide free access to its articles. An important aspect of Ambi-Água is the publication and management system of this journal. It uses the Electronic System for Journal Publishing (SEER - http://www.ibict.br/secao.php?cat=SEER. This system was translated and customized by the Brazilian Institute for Science and Technology Information (IBICT based on the software developed by the Public Knowledge Project (Open Journal Systems of the British Columbia University (http://pkp.sfu.ca/ojs/. The big advantage of using this system is that it is compatible with the OAI-PMH protocol for metadata harvesting what greatly promotes published articles
4. The Monitoring of Some Blood Physiological and Biochemical Index of Cows During Perinatal Period%围产期奶牛几种血液生理生化指标监测
Institute of Scientific and Technical Information of China (English)
李俊杰; 申国新; 汪恩强; 安锡忠; 陨祺
2014-01-01
为了监测和诊断围产期奶牛常见营养代谢病，分别对产前15d、产前7d、产前1d、产后1d、产后7d、产后15d各10头共计60头围产期奶牛进行血液生理生化指标检测。结果显示，在整个围产期内奶牛血液中白细胞数、红细胞数、血红蛋白含量和红细胞压积差异不显著，不能作为围产期奶牛营养代谢病的监测依据。产前1d奶牛血清游离脂肪酸含量最低，为460.76±268.34μmol/L，与产前15d、产后7d、产后15d比较差异极显著(P<0.01)。产后7d奶牛血清葡萄糖含量最低，为2.12±0.35mmol/L，与其他时间测定值比较差异极显著(P<0.01)。产后1d奶牛血清中门冬氨酸氨基转移酶的含量最高，为15.33±3.24U/L，与产前15d、产前7d比较差异极显著(P<0.01)。产后15d奶牛血清中谷丙转氨酶活性和甘油三酯含量升高，分别为14.10±4.40 U/L和0.90±0.14mmol/L，与产前不同时期比较差异极显著(P<0.01)。产后1d血清Ca含量降至最低值，为1.76±0.32mmol/L，血清羟脯氨酸含量和碱性磷酸酶活性升高，分别为25.50±7.90μmol/L和85.13±7.57IU/L，与产前不同时期比较差异极显著(P<0.01)。结果表明，利用血清游离脂肪酸、血清葡萄糖含量和血清门冬氨酸氨基转移酶活性，按公式计算Y值可作为诊断奶牛脂肪肝的依据。奶牛血清钙含量降低，血清羟脯氨酸含量和血清碱性磷酸酶活性升高可作为奶牛骨营养不良的诊断依据。尿酮体监测可作为奶牛酮病的诊断依据。%In order to monitor and diagnose common perinatal cow nutrition and metabolic diseases,totally 60 perinatal cows (10 cows respectively in prenatal 15d, prenatal 7d, prenatal 1d, postpartum 1d, postpartum 7d, postpartum 15d) were selected for physiological and biochemical blood testing. The experimental results showed that:all transition cows white blood cell count, red blood cell count, hemoglobin and hematocrit of blood were
5. Towards Cryptocurrency Index
OpenAIRE
Trimborn, Simon
2015-01-01
In dieser Thesis wird ein Marktindex konstruiert, wobei neu entwickelte Methoden für solch eine Aufgabe verwendet werden. Die Entscheidung über die Anzahl der Indexteilnehmer wird mithilfe des AIC und BIC Kriteriums getroffen und die Liquiditätsregel wird auf Grundlage der BIS Umfrage ermittelt. Dieser neu entwickelte Index, CRIX, wird dann benutzt, um den Kryptowährungsmarkt gegen Bitcoins und andere Märkte zu vergleichen. Es wurde herausgefunden, dass dieser Markt wesentlich risikoreicher i...
6. Indexing dif/2
OpenAIRE
Neumerkel, Ulrich; Kral, Stefan
2016-01-01
Many Prolog programs are unnecessarily impure because of inadequate means to express syntactic inequality. While the frequently provided built-in dif/2 is able to correctly describe expected answers, its direct use in programs often leads to overly complex and inefficient definitions --- mainly due to the lack of adequate indexing mechanisms. We propose to overcome these problems by using a new predicate that subsumes both equality and inequality via reification. Code complexity is reduced ...
7. A data fusion-based drought index
Science.gov (United States)
Azmi, Mohammad; Rüdiger, Christoph; Walker, Jeffrey P.
2016-03-01
Drought and water stress monitoring plays an important role in the management of water resources, especially during periods of extreme climate conditions. Here, a data fusion-based drought index (DFDI) has been developed and analyzed for three different locations of varying land use and climate regimes in Australia. The proposed index comprehensively considers all types of drought through a selection of indices and proxies associated with each drought type. In deriving the proposed index, weekly data from three different data sources (OzFlux Network, Asia-Pacific Water Monitor, and MODIS-Terra satellite) were employed to first derive commonly used individual standardized drought indices (SDIs), which were then grouped using an advanced clustering method. Next, three different multivariate methods (principal component analysis, factor analysis, and independent component analysis) were utilized to aggregate the SDIs located within each group. For the two clusters in which the grouped SDIs best reflected the water availability and vegetation conditions, the variables were aggregated based on an averaging between the standardized first principal components of the different multivariate methods. Then, considering those two aggregated indices as well as the classifications of months (dry/wet months and active/non-active months), the proposed DFDI was developed. Finally, the symbolic regression method was used to derive mathematical equations for the proposed DFDI. The results presented here show that the proposed index has revealed new aspects in water stress monitoring which previous indices were not able to, by simultaneously considering both hydrometeorological and ecological concepts to define the real water stress of the study areas.
8. The application of index of consciousness monitoring in artificial abortion surgery%意识指数监测在无痛人工流产术中的应用
Institute of Scientific and Technical Information of China (English)
李茜; 张丽; 吴慧
2014-01-01
目的 探讨意识指数(index of consciousness,IoC)监测指导无痛人工流产术中丙泊酚用药的可行性.方法 选择自愿行无痛人工流产者100例,年龄20～30岁,ASA Ⅰ或Ⅱ级,采用随机数字表法将患者均分为IoC监测组(IoC组)和临床组(C组).两组患者均采用TCI丙泊酚复合芬太尼麻醉,丙泊酚血浆靶浓度从4.0μg/ml起始,静脉缓慢注射芬太尼1.0μg/kg.IoC组TCI丙泊酚至IoC指数为40～60之间,将IoC始终维持在45±3,且根据IoC值调整丙泊酚血浆靶浓度;C组采用改良OAA/S评分对患者进行镇静评估,输注丙泊酚至OAA/S评分达到1分(对轻度摇动患者躯体无反应).记录给药前、睫毛反射消失、扩宫、吸宫和清醒时的MAP、HR、SpO2,记录丙泊酚用量、术后苏醒时间及定向力恢复时间,观察术中不良反应发生情况.结果 与C组比较,IoC组丙泊酚用量减少,苏醒时间及定向力恢复时间明显缩短(P＜0.05);体动发生率明显降低(P＜0.05),而两组呼吸抑制、头晕、恶心呕吐发生率差异均无统计学意义.与给药前比较,睫毛反射消失、扩宫、吸宫时两组患者MAP明显降低,HR明显减慢(P＜0.05),SpO2差异无统计学意义.结论 IoC监测对无痛人工流产术中的丙泊酚用药和麻醉深度调控有很好的指导意义.
9. Development and evaluation of a physically based multiscalar drought index: The Standardized Moisture Anomaly Index
Science.gov (United States)
Zhang, Baoqing; Zhao, Xining; Jin, Jiming; Wu, Pute
2015-11-01
In this study, a new physically based multiscalar drought index, the Standardized Moisture Anomaly Index (SZI), was developed and evaluated, which combines the advantages of the Palmer Drought Severity Index (PDSI) and the Standardized Precipitation Evapotranspiration Index (SPEI). The SZI is based on the water budget simulations produced with a sophisticated hydrological model, and it also includes a multiscalar feature to quantify drought events at different temporal scales taken from SPEI. The Chinese Loess Plateau was selected to evaluate the performance of the SZI. Our evaluation indicates that the SZI accurately captures the onset, duration, and ending of a multiyear drought event through its multiscalar feature, while the PDSI, which lacks this feature, is often unable to describe the evolution of a multiyear drought event. In addition, the variability of the SZI is more consistent with observed streamflow and the satellite normalized difference vegetation index than that of the Standardized Precipitation Index and the SPEI. Although the SPEI includes potential evapotranspiration (PE) as water demand, water demand is often unrealistically estimated based solely on PE, especially over arid and semiarid regions. The improved drought quantification with the SZI is the result of a more reasonable estimation of water demand by including evapotranspiration, runoff, and any change in soil moisture storage. In general, our newly developed SZI is physically based and includes a multiscalar feature, which enables it to provide better information for drought monitoring and identification at different temporal scales.
10. Refractive index based measurements
DEFF Research Database (Denmark)
2014-01-01
In a method for performing a refractive index based measurement of a property of a fluid such as chemical composition or temperature by observing an apparent angular shift in an interference fringe pattern produced by back or forward scattering interferometry, ambiguities in the measurement caused...... by the apparent shift being consistent with one of a number of numerical possibilities for the real shift which differ by 2n are resolved by combining measurements performed on the same sample using light paths therethrough of differing lengths....
11. Negative refractive index metamaterials
Directory of Open Access Journals (Sweden)
2006-07-01
Full Text Available Engineered materials composed of designed inclusions can exhibit exotic and unique electromagnetic properties not inherent in the individual constituent components. These artificially structured composites, known as metamaterials, have the potential to fill critical voids in the electromagnetic spectrum where material response is limited and enable the construction of novel devices. Recently, metamaterials that display negative refractive index – a property not found in any known naturally occurring material – have drawn significant scientific interest, underscoring the remarkable potential of metamaterials to facilitate new developments in electromagnetism.
12. Measuring Key Disparities in Human Development: The Gender Inequality Index
OpenAIRE
Amie Gaye; Jeni Klugman; Milorad Kovacevic; Sarah Twigg; Eduardo Zambrano
2010-01-01
Gender inequality remains a major barrier to human development. Girls and women have made major strides since 1990, but they have not yet gained gender equity. In this paper, we review ways to measure and monitor gender inequality, providing a critique of existing measures including the first global gender indices that were launched in the 1995 Human Development Report – the Gender-related Development Index and the Gender Empowerment Measure - and introduce a new index that is presented in th...
13. Recurrence Plots for the analysis of Vegetation Health Index (VHI)
OpenAIRE
Sparavigna, Amelia Carolina
2015-01-01
Many satellite and information services, such as NOAA STAR, are providing maps displaying data about vegetation indices. Using the time-series that we can obtain from these maps, several analyses are possible. Here we propose the use of recurrence plots. We will show examples based on the data corresponding to three small areas in Italy of the NOAA STAR Vegetation Health Index (VHI), an index used for monitoring and forecasting the status of vegetation. The recurrence plots we obtained seem b...
14. Index Sets and Vectorization
Energy Technology Data Exchange (ETDEWEB)
Keasler, J A
2012-03-27
Vectorization is data parallelism (SIMD, SIMT, etc.) - extension of ISA enabling the same instruction to be performed on multiple data items simultaeously. Many/most CPUs support vectorization in some form. Vectorization is difficult to enable, but can yield large efficiency gains. Extra programmer effort is required because: (1) not all algorithms can be vectorized (regular algorithm structure and fine-grain parallelism must be used); (2) most CPUs have data alignment restrictions for load/store operations (obey or risk incorrect code); (3) special directives are often needed to enable vectorization; and (4) vector instructions are architecture-specific. Vectorization is the best way to optimize for power and performance due to reduced clock cycles. When data is organized properly, a vector load instruction (i.e. movaps) can replace 'normal' load instructions (i.e. movsd). Vector operations can potentially have a smaller footprint in the instruction cache when fewer instructions need to be executed. Hybrid index sets insulate users from architecture specific details. We have applied hybrid index sets to achieve optimal vectorization. We can extend this concept to handle other programming models.
15. Torsadogenic index for prevention of acute death
Institute of Scientific and Technical Information of China (English)
2015-01-01
This risk management project aims to apply a global preventive and predictive measure in potential victims of acute death and heart failure. Among the main causes are identified sub-diagnosed genetic mutations; prescription, interaction, self-medication or abuse of suspected drugs due to internet prospect's consult; and a parasitic pandemia, the Chagas disease (over 100 000 000 population is potentially infected worldwide). Promoting a global extensive determination of the torsadogenic index which was successfully published in Frontiers of Pharmacology Journal, will allow to monitor general population, set security patterns to categorize silent high risk groups of serious prognosis of tachyarhythmias. For this purpose, applications of known QT determinations are proposed, recommending Dr. Rautaharju's formula, actually improved with gender adult versions. Torsadogenic index will allow to establish an individual traceability, obtain comparative samples that are alert to possible QT enlargements. Thus, torsadogenic index results a valuable, simple and costless resource to consider in the fight against acute death and cardiac arrest. Torsadogenic index represents a global indicator capable of predicting and preventing acute death and heart failure for most relevant reasons.
16. Relação entre a infusão contínua de dexmedetomidina e a fração expirada de sevoflurano monitorizada pelo índice bispectral
Directory of Open Access Journals (Sweden)
Magalhães Edno
2004-01-01
17. An improved molecular connectivity index
Institute of Scientific and Technical Information of China (English)
李新华; 俞庆森; 朱龙观
2000-01-01
Through modification of the delta values of the molecular connectivity indexes, and connecting the quantum chemistry with topology method effectively, the molecular connectivity indexes are converted into quantum-topology indexes. The modified indexes not only keep all information obtained from the original molecular connectivity method but also have their own virtue in application, and at the same time make up some disadvantages of the quantum and molecular connectivity methods.
18. Monitoring the source monitoring.
Science.gov (United States)
Luna, Karlos; Martín-Luengo, Beatriz
2013-11-01
19. EXFOR-INDEX. Index to EXFOR Neutron Data 1985
International Nuclear Information System (INIS)
This document summarizes the contents and documentation of the Index File to EXFOR Neutron Data (X4INDEX). This library is a sequential file of relevant index records extracted from an online Data Index data base at NDS. The data base is updated regularly, and each copy of the EXFOR Neutron Data Index is extracted directly from the current data base file. The second file of the EXFOR Neutron Data Index library is a copy of the relevant EXFOR dictionaries. This file is copied directly from the EXFOR Dictionary master file. The entire Index or selective retrievals from it can be obtained on magnetic tape free of charge from the IAEA Nuclear Data Section. (author)
20. The Financial Stress Index: Identification of Systemic Risk Conditions
Directory of Open Access Journals (Sweden)
Mikhail V. Oet
2015-09-01
Full Text Available This paper develops a financial stress measure for the United States, the Cleveland Financial Stress Index (CFSI. The index is based on publicly available data describing a six-market partition of the financial system comprising credit, funding, real estate, securitization, foreign exchange, and equity markets. This paper improves upon existing stress measures by objectively selecting between several index weighting methodologies across a variety of monitoring frequencies through comparison against a volatility-based benchmark series. The resulting measure facilitates the decomposition of stress to identify disruptions in specific markets and provides insight into historical stress regimes.
1. Automated Water Extraction Index
DEFF Research Database (Denmark)
Feyisa, Gudina Legese; Meilby, Henrik; Fensholt, Rasmus;
2014-01-01
Classifying surface cover types and analyzing changes are among the most common applications of remote sensing. One of the most basic classification tasks is to distinguish water bodies from dry land surfaces. Landsat imagery is among the most widely used sources of data in remote sensing of water...... resources; and although several techniques of surface water extraction using Landsat data are described in the literature, their application is constrained by low accuracy in various situations. Besides, with the use of techniques such as single band thresholding and two-band indices, identifying...... an appropriate threshold yielding the highest possible accuracy is a challenging and time consuming task, as threshold values vary with location and time of image acquisition. The purpose of this study was therefore to devise an index that consistently improves water extraction accuracy in the presence...
2. Rapid shallow breathing index.
Science.gov (United States)
Karthika, Manjush; Al Enezi, Farhan A; Pillai, Lalitha V; Arabi, Yaseen M
2016-01-01
Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed. PMID:27512505
3. A quality adjusted wage index
OpenAIRE
Jennjou Chen; Butler, J. S.
2006-01-01
In this paper, a new method of estimating a wage index is proposed and implemented. We construct a wage index by controlling for quantity, as well as quality of labor. Our approach uses a set of year dummies as the basis for calculation of a wage index. The March Current Population Survey Supplement (1983-2000) is employed, and empirical wage equation models are estimated in this paper. The estimation results of the proposed wage index suggest that the existing Employment Cost Index perhaps o...
4. Monitor Cross-over Creatieve Industrie
OpenAIRE
Giessen, A.M. van der; Koops, R.; Nieuwenhuis, O.A.; van Nunen, A.M.
2015-01-01
Op het gebied van de creatieve industrie wordt veel gemonitord en geëvalueerd. Voorbeelden hiervan zijn de Cross Media Monitor, sinds dit jaar bekend onder de naam Monitor Creatieve Industrie (Immovator, 2014), Monitor topsectoren (CBS, 2014), diverse regionale monitors (o.a. Amsterdam (van der Groep, van Oosteren, & de Jong, 2010), Gamesmonitor (Taskforce Innovatie Regio Utrecht, 2013), Cultuur Index (Boekmanstichting) en internationale monitoren (zoals MCI van het Europese onderzoeksinstitu...
5. Application of pulse index continuous cardiac output monitoring to improve efficiency of acute heart failure care%应用脉搏指数连续心输出量监测提升急性心力衰竭护理效果
Institute of Scientific and Technical Information of China (English)
孙秀月; 张领; 赵书琴
2015-01-01
Objective To ihvestigate the effect of pulse index continuous cardiac output (PiCCO) monitoring to nursing care of acute heart failure care.Methods The clinical data of 43 acute heart failure patients were retrospectively analyzed,patients were given pulse index continuous cardiac output monitoring and care,the patient' s nursing outcomes were observed,and the intrathoracic blood volume,cardiac output and oxygen consumption before and after the intervention were compared.Results After the implementation of PiCCO and nursing intervention,43 patients had no serious complications,improved 42 cases discharged,the other 1 patient in critical condition due to old age and heart function improvement sustained no automatic discharge.Oxygen consumption,cardiac output and intrathoracic blood volume were improved after the intervention,there was a significant difference (P ＜ 0.05) compared to the previous indicators and intervention after intervention.Conclusions Application of pulse index continuous cardiac output can effectively improve patient's clinical parameters such as cardiac output,through the implementation of appropriate care can improve symptoms and reduce complications.%目的 探讨急性心力衰竭患者护理中应用脉搏指数连续心输出量监测(PiCCO)的效果.方法 选取平顶山市第二人民医院收治的43例急性心力衰竭患者作为研究对象,收集患者的临床资料并对其做回顾性分析,对患者实施脉搏指数连续心输出量监测和护理,对患者的护理效果进行观察,并对其干预前后的胸腔内血容量、心排血量与氧耗量进行对比观察.结果 实施PiCCO和护理干预,本研究43例患者均无严重并发症产生,42例好转出院,1例由于病情危重、高龄及心功能持续无改善自动出院.患者干预后的氧耗量、心排血量与胸腔内血容量均有所改善,干预后各项指标与干预前比较差异有统计学意义(P＜0.05).结论 应用脉搏指数连续心
6. A clinical index for evaluating and monitoring dental erosion
DEFF Research Database (Denmark)
Larsen, I B; Westergaard, J; Stoltze, K;
2000-01-01
This study describes a new fine-scaled system for classifying initial and advanced dental erosions. The system includes the use of study casts of the teeth in an epoxy resin with an accurate surface reproduction. The severity of erosion on each tooth surface is scored according to six grades of s...
7. SPECTRAL VEGETATION INDEX RELATIONSHIPS WITH NORMALIZED YIELD MONITOR DATA
Science.gov (United States)
The delineation of crop response zones to identify within-field areas where productivity varies with seasonal precipitation patterns can be used as an indicator of subsurface water flow, and is a first step towards delineating management zones for precision farming as a function of water availabilit...
8. Generalizations of Wiener polarity index and terminal Wiener index
CERN Document Server
Ilic, Aleksandar
2011-01-01
In theoretical chemistry, distance-based molecular structure descriptors are used for modeling physical, pharmacologic, biological and other properties of chemical compounds. We introduce a generalized Wiener polarity index $W_k (G)$ as the number of unordered pairs of vertices $\\{u, v\\}$ of $G$ such that the shortest distance $d (u, v)$ between $u$ and $v$ is $k$. For $k = 3$, we get standard Wiener polarity index. Furthermore, we generalize the terminal Wiener index $TW_k (G)$ as the sum of distances between all pairs of vertices of degree $k$. For $k = 1$, we get standard terminal Wiener index. In this paper we describe a linear time algorithm for computing these indices for trees and partial cubes, and characterize extremal trees maximizing the generalized Wiener polarity index and generalized terminal Wiener index among all trees of given order $n$.
9. Monitoring with Data Automata
Science.gov (United States)
Havelund, Klaus
2014-01-01
We present a form of automaton, referred to as data automata, suited for monitoring sequences of data-carrying events, for example emitted by an executing software system. This form of automata allows states to be parameterized with data, forming named records, which are stored in an efficiently indexed data structure, a form of database. This very explicit approach differs from other automaton-based monitoring approaches. Data automata are also characterized by allowing transition conditions to refer to other parameterized states, and by allowing transitions sequences. The presented automaton concept is inspired by rule-based systems, especially the Rete algorithm, which is one of the well-established algorithms for executing rule-based systems. We present an optimized external DSL for data automata, as well as a comparable unoptimized internal DSL (API) in the Scala programming language, in order to compare the two solutions. An evaluation compares these two solutions to several other monitoring systems.
10. 2012 Environmental Performance Index and Pilot Trend Environmental Performance Index
Data.gov (United States)
National Aeronautics and Space Administration — The 2012 Environmental Performance Index (EPI) ranks 132 countries on 22 performance indicators in the following 10 policy categories: environmental burden of...
11. Ankle Brachial Index
Energy Technology Data Exchange (ETDEWEB)
Wikstroem, J.; Hansen, T.; Johansson, L.; Lind, L.; Ahlstroem, H. (Dept. of Radiology and Dept. of Medical Sciences, Uppsala Univ. Hospital, Uppsala (SE))
2008-03-15
Background: Whole-body magnetic resonance angiography (WBMRA) permits noninvasive vascular assessment, which can be utilized in epidemiological studies. Purpose: To assess the relation between a low ankle brachial index (ABI) and high-grade stenoses in the pelvic and leg arteries in the elderly. Material and Methods: WBMRA was performed in a population sample of 306 subjects aged 70 years. The arteries below the aortic bifurcation were graded after the most severe stenosis according to one of three grades: 0-49% stenosis, 50-99% stenosis, or occlusion. ABI was calculated for each side. Results: There were assessable WBMRA and ABI examinations in 268 (right side), 265 (left side), and 258 cases (both sides). At least one >=50% stenosis was found in 19% (right side), 23% (left side), and 28% (on at least one side) of the cases. The corresponding prevalences for ABI <0.9 were 4.5%, 4.2%, and 6.6%. An ABI cut-off value of 0.9 resulted in a sensitivity, specificity, and positive and negative predictive value of 20%, 99%, 83%, and 84% on the right side, and 15%, 99%, 82%, and 80% on the left side, respectively, for the presence of a >= 50% stenosis in the pelvic or leg arteries. Conclusion: An ABI <0.9 underestimates the prevalence of peripheral arterial occlusive disease in the general elderly population
12. Indexing for summary queries
DEFF Research Database (Denmark)
Yi, Ke; Wang, Lu; Wei, Zhewei
2014-01-01
Database queries can be broadly classified into two categories: reporting queries and aggregation queries. The former retrieves a collection of records from the database that match the query's conditions, while the latter returns an aggregate, such as count, sum, average, or max (min), of a parti....... Our indexes require linear space and extract a summary with the optimal or near-optimal query cost. We illustrate the efficiency and usefulness of our designs through extensive experiments and a system demonstration.......Database queries can be broadly classified into two categories: reporting queries and aggregation queries. The former retrieves a collection of records from the database that match the query's conditions, while the latter returns an aggregate, such as count, sum, average, or max (min), of a...... particular attribute of these records. Aggregation queries are especially useful in business intelligence and data analysis applications where users are interested not in the actual records, but some statistics of them. They can also be executed much more efficiently than reporting queries, by embedding...
13. The future of anaesthesiology
OpenAIRE
Ankit Agarwal
2012-01-01
There was an era when bark of mandrake plant, boiled in wine was used to administer anesthesia. Ether, after reigning the kingdom of anaesthesiology for more than a century, came to be superseded by newer and newer agents. Anaesthesiology has witnessed tremendous developments since infancy. The introduction of advanced airway adjuncts, labour analgesia, patient controlled analgesia, fibreoptics, Bispectral Index monitors, workstations, simulators and robotic surgeries are only to name a furth...
14. A Global Grassland Drought Index (GDI Product: Algorithm and Validation
Directory of Open Access Journals (Sweden)
Binbin He
2015-09-01
Full Text Available Existing drought indices have been widely used to monitor meteorological drought and agricultural drought; however, few of them are focus on drought monitoring for grassland regions. This study presented a new drought index, the Grassland Drought Index (GDI, for monitoring drought conditions in global grassland regions. These regions are vital for the environment and human society but susceptible to drought. The GDI was constructed based on three measures of water content: precipitation, soil moisture (SM, and canopy water content (CWC. The precipitation information was extracted from the available precipitation datasets, and SM was estimated by downscaling exiting soil moisture data to a 1 km resolution, and CWC was retrieved based on the PROSAIL (PROSPECT + SAIL model. Each variable was scaled from 0 to 1 for each pixel based on absolute minimum and maximum values over time, and these scaled variables were combined with the selected weights to construct the GDI. According to validation at the regional scale, the GDI was correlated with the Standardized Precipitation Index (SPI to some extent, and captured most of the drought area identified by the United States Drought Monitor (USDM maps. In addition, the global GDI product at a 1 km spatial resolution substantially agreed with the global Standardized Precipitation Evapotranspiration Index (SPEI product throughout the period 2005–2010, and it provided detailed and accurate information about the location and the duration of drought based on the evaluation using the known drought events.
15. Effect of temperature on oil stability index (OSI) of biodiesel
Science.gov (United States)
Biodiesel is primarily composed of saturated and unsaturated fatty acid alkyl esters. Fuel suppliers, terminal operators and users are becoming more concerned with monitoring and maintaining good biodiesel fuel quality with respect to oxidative degradation during storage. Oil stability index (OSI)...
16. A house price index based on the SPAR method
NARCIS (Netherlands)
De Vries, P.; De Haan, J.; Mariën, A.A.A.; Van der Wal, E.
2009-01-01
Within the European Union there has been a push to provide European governments and the European Central Bank with the statistics they need for monitoring the owneroccupied sector. This paper reports on the results of a project to develop a house price index for the Netherlands. From January 2008, K
17. The Good African Society Index
OpenAIRE
Ferdi Botha
2014-01-01
This paper constructs a Good Society Index for 45 African countries, termed the Good African Society Index (GASI). The GASI consists of nine main indexes: (i) economic sustainability, (ii) democracy and freedom, (iii) child well-being, (iv) environment and infrastructure, (v) safety and security, (vi) health and health systems, (vii) integrity and justice, (viii) education, and (xi) social sustainability and social cohesion. Each component is split into four sub-components for a total of 36 i...
18. Index effects: Evidence from Australia
OpenAIRE
Zhao R; Schmidt C.; Terry C
2016-01-01
This paper presents the findings of the first study of the index effects from changes in the composition of Australia’s tradeable benchmark index: the S&P/ASX 200. Prior to the introduction of the S&P/ASX200 changes to the composition of the market’s (then) benchmark index (the All Ordinaries Index) became evident before the formal announcement dates and the changes were made the following trading day. These announcement arrangements enabled profitable front-running trading. Along with the in...
19. Index Bioclimatic "Wind-Chill"
Directory of Open Access Journals (Sweden)
Teodoreanu Elena
2015-05-01
Full Text Available This paper presents an important bioclimatic index which shows the influence of wind on the human body thermoregulation. When the air temperature is high, the wind increases thermal comfort. But more important for the body is the wind when the air temperature is low. When the air temperature is lower and wind speed higher, the human body is threatening to freeze faster. Cold wind index is used in Canada, USA, Russia (temperature "equivalent" to the facial skin etc., in the weather forecast every day in the cold season. The index can be used and for bioclimatic regionalization, in the form of skin temperature index.
20. 2008 Environmental Performance Index (EPI)
Data.gov (United States)
National Aeronautics and Space Administration — The 2008 Environmental Performance Index (EPI) centers on two broad environmental protection objectives: (1) reducing environmental stresses on human health, and...
1. Nelson-Farrar cost indexes
International Nuclear Information System (INIS)
This paper discusses the Nelson-Farrar Cost Indexs. Topics covered include: economic analysis, petroleum refineries, petroleum industry, pumps, compressors, beat exchangers, cost estimation, productivity and wages
2. Malaysian Education Index (MEI): An Online Indexing and Repository System
Science.gov (United States)
Kabilan, Muhammad Kamarul; Ismail, Hairul Nizam; Yaakub, Rohizani; Yusof, Najeemah Mohd; Idros, Sharifah Noraidah Syed; Umar, Irfan Naufal; Arshad, Muhammad Rafie Mohd.; Idrus, Rosnah; Rahman, Habsah Abdul
2010-01-01
This "Project Sheet" describes an on-going project that is being carried out by a group of educational researchers, computer science researchers and librarians from Universiti Sains Malaysia, Penang. The Malaysian Education Index (MEI) has two main functions--(1) Online Indexing System, and (2) Online Repository System. In this brief…
3. Risk monitors
International Nuclear Information System (INIS)
The aim of the presentation is to gain an understanding of the following: The relationship between the PSA and a safety monitor; the functions performed by safety monitor; typical operational specification; modeling requirements
4. Monitoring system
International Nuclear Information System (INIS)
The patent relates to monitoring systems for, and a method of monitoring, industrial process plants or apparatus. The system monitors a plurality of data signals representing a number of parameters of a plant or apparatus. One application of the invention is in nuclear reactors for the detection of fault conditions. (U.K.)
5. Satisfiability with Index Dependency
Institute of Scientific and Technical Information of China (English)
Hong-Yu Liang; Jing He
2012-01-01
We study the Boolean satisfiability problem (SAT) restricted on input formulas for which there are linear arithmetic constraints imposed on the indices of variables occurring in the same clause.This can be seen as a structural counterpart of Schaefer's dichotomy theorem which studies the SAT problem with additional constraints on the assigned values of variables in the same clause.More precisely,let k-SAT(m,A) denote the SAT problem restricted on instances of k-CNF formulas,in every clause of which the indices of the last k-m variables are totally decided by the first m ones through some linear equations chosen from A.For example,if A contains i3 =i1+2i2 and i4 =i2-i1 + 1,then a clause of the input to 4-SAT(2,A) has the form yi1∨yi2∨yi1+2i2∨yi2-i1+1,with yi being xi or (xi).We obtain the following results:1) If m ≥2,then for any set A of linear constraints,the restricted problem k-SAT(m,A) is either in P or NP-complete assuming P ≠ NP.Moreover,the corresponding #SAT problem is always #P-complete,and the MAx-SAT problem does not allow a polynomial time approximation scheme assuming P ≠ NP.2) m =1,that is,in every clause only one index can be chosen freely.In this case,we develop a general framework together with some techniques for designing polynomial-time algorithms for the restricted SAT problems.Using these,we prove that for any A,#2-SAT(1,A) and MAX-2-SAT(1,A) are both polynomial-time solvable,which is in sharp contrast with the hardness results of general #2-SAT and MAX-2-SAT.For fixed k≥ 3,we obtain a large class of non-trivial constraints A,under which the problems k-SAT(1,A),#k-SAT(1,A)and MAx-k-SAT(1,A) can all be solved in polynomial time or quasi-polynomial time.
6. Nonlinearity detection for condition monitoring utilizing higher-order spectral analysis diagnostics
Science.gov (United States)
Park, Hyeonsu
In this dissertation, we investigate the theory and application of higher-order spectral analysis techniques to condition monitoring in shipboard electrical power systems. Monitoring and early detection of faults in rotating machines, such as induction motors, are essential for both preventive maintenance and to avoid potentially severe damage. As machines degrade, they often tend to become more nonlinear. This increased nonlinearity results in the introduction of new frequencies which satisfy particular frequency selection rules; the exact selection rule depends on the order of the nonlinearity. In addition, the phases of the newly generated frequencies satisfy a similar phase selection rule. This results in a phase coherence, or phase coupling, between the "original" interacting frequencies and the "new" frequencies. This phase coupling is a true signature of nonlinearity. Since the classical auto-power spectrum contains no phase information, the phase coupling signature associated with nonlinear interactions is not available. However, various higher-order spectra (HOS) are capable of detecting such nonlinear-induced phase coupling. The efficacy of the various proposed HOS-based methodologies is investigated using real-world vibration time-series data from a faulted induction motor driving a dc generator. The fault is controlled by varying a resistor placed in one phase of the three-phase line to the induction motor. First, we propose a novel method using a bispectral change detection (BCD) for condition monitoring. Even though the bicoherence is dominant and powerful in the detection of phase coupling of nonlinearly interacting frequencies, it has some difficulties in its application to machine condition monitoring. Basically, the bicoherence may not be able to distinguish between intrinsic nonlinearities associated with healthy machines and fault-induced nonlinearities. Therefore, the ability to discriminate the fault-only nonlinearities from the intrinsic
7. Maslov index for Hamiltonian systems
Directory of Open Access Journals (Sweden)
Alessandro Portaluri
2008-01-01
Full Text Available The aim of this article is to give an explicit formula for computing the Maslov index of the fundamental solutions of linear autonomous Hamiltonian systems in terms of the Conley-Zehnder index and the map time one flow.
8. Simplifying the Water Poverty Index
Science.gov (United States)
Cho, Danny I.; Ogwang, Tomson; Opio, Christopher
2010-01-01
In this paper, principal components methodology is used to derive simplified and cost effective indexes of water poverty. Using a well known data set for 147 countries from which an earlier five-component water poverty index comprising of "Resources," "Access," "Capacity," "Use" and "Environment" was constructed, we find that a simplified…
9. The Carbon City Index (CCI)
DEFF Research Database (Denmark)
Boyd, Britta; Straatman, Bas; Mangalagiu, Diana;
This paper presents a consumption-based Carbon City Index for CO2 emissions in a city. The index is derived from regional consumption and not from regional production. It includes imports and exports of emissions, factual emission developments, green investments as well as low carbon city...
10. A temporary index
International Nuclear Information System (INIS)
The ongoing management of low, intermediate and high-level nuclear waste is an unresolved issue for humanity, not least because the time-frames in question when dealing with the hazards of radioactive wastes, range from as little as a few tens of years to more than 100 000 years. It is from this starting point that we are beginning the development of an ambitious multifaceted artwork aiming to help us consider our relationship with deep-time and our nuclear legacy. The expressed aim of Temporary Index is to raise general awareness about these long-term management issues, and in doing so, to embed this knowledge into our collective cultural memory so as to transmit useful information about our nuclear waste into the future. We wish to create a series of decorative, real-time numeric counters based on the probabilistic decay (including decay of daughter products) of existing nuclear waste that we identify from the earliest weapons' development programmes in the United States right through to contemporary wastes being produced by nuclear energy production today across the world. Each display will countdown in seconds, showing the time remaining before the given item of waste (or a particular site) is considered safe to humans. A hypothetical example of one counter could be a bottle of sludge containing plutonium discovered in 2004 during an attempted clean-up of the Hanford nuclear site in Washington State, United States. Another example might be the geological storage facility for vitrified nuclear waste at Horonobe in Japan, should it be established in the future. Accident sites, such as Chernobyl or Fukushima Daiichi could also be tagged with counters, as could low-level waste (LLW) repositories such as the one at Drigg near Sellafield in the United Kingdom. Whatever the items identified and this will be a complex process requiring collaboration with experts in the field, it is important that a wide range of short- and long-term counters are established to
11. Trajectory Indexing Using Movement Constraints
DEFF Research Database (Denmark)
Pfoser, D.; Jensen, Christian Søndergaard
2005-01-01
-the-shelf database management systems typically do not offer higher-dimensional indexing, this reduction in dimensionality allows us to use existing DBMSes to store and index trajectories. Moreover, we argue that, given the right circumstances, indexing these dimensionality-reduced trajectories can be more efficient......With the proliferation of mobile computing, the ability to index efficiently the movements of mobile objects becomes important. Objects are typically seen as moving in two-dimensional (x,y) space, which means that their movements across time may be embedded in the three-dimensional (x,y,t) space...... than using a three-dimensional index. A decisive factor here is the fractal dimension of the network.the lower, the more efficient is the proposed approach. This hypothesis is verified by an experimental study that incorporates trajectories stemming from real and synthetic road networks....
12. Louisiana ESI: LG_INDEX (Large Index Polygons)
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all the hardcopy cartographic products produced as part of the Environmental Sensitivity Index...
13. Cook Inlet and Kenai Peninsula, Alaska ESI: INDEX (Index Polygons)
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries used in the creation of the Environmental Sensitivity Index (ESI) for Cook Inlet and Kenai...
14. Bristol Bay, Alaska Subarea ESI: INDEX (Index Polygons)
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all the hardcopy cartographic products produced as part of the Environmental Sensitivity Index...
15. Guam and the Northern Mariana Islands ESI: INDEX (Index Polygons)
Data.gov (United States)
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all hardcopy cartographic products produced as part of the Environmental Sensitivity Index...
16. Firm Sustainability Performance Index Modeling
Directory of Open Access Journals (Sweden)
Che Wan Jasimah Bt Wan Mohamed Radzi
2015-12-01
Full Text Available The main objective of this paper is to bring a model for firm sustainability performance index by applying both classical and Bayesian structural equation modeling (parametric and semi-parametric modeling. Both techniques are considered to the research data collected based on a survey directed to the China, Taiwan, and Malaysia food manufacturing industry. For estimating firm sustainability performance index we consider three main indicators include knowledge management, organizational learning, and business strategy. Based on the both Bayesian and classical methodology, we confirmed that knowledge management and business strategy have significant impact on firm sustainability performance index.
17. An Index for Venture Capital
OpenAIRE
Quigley, John M.; Susan E. Woodward
2003-01-01
In this paper we build an index of value for venture capital. Our approach overcomes the problems of intermittent, infrequent pricing of private company deals by using a repeat valuation model to build the index, and it corrects for selection bias in the reporting of values. We use a unique data set from Sand Hill Econometrics. The index measures the return and risk for venture capital. Its covariance with other asset classes from 1987-1999 enables us to explore the role of venture capita...
18. Estimation of rice situation index in Japan using remotely sensed and meteorological data
International Nuclear Information System (INIS)
This research aims to develop a remote sensing method for monitoring rice production in Japan. A photosynthesis-based crop production index CPI for rice is proposed that takes into consideration the solar radiation, the effective air temperature, and normalized vegetation index NDVI as a factor representing vegetation biomass. The CPI index incorporates temperature influences such as the effect of temperature on photosynthesis by grain plant leaves, low-temperature effects of sterility, cool summer damage due to delayed growth, and high-temperature injury. These latter factors are significant at around the heading period of rice. The CPI index for rice was modeled at ten monitoring sites in the Kanto, Tohoku, and Hokkaido districts, which occasionally tend to suffer poor harvests as a result of low temperatures. The photosynthesis-based crop production index CPI proposed here can predict the crop situation index of rice by using NDVI, solar radiation at meteorological observatories and air temperature at AMeDAS sites. The method is based on routine observation data, allowing automated monitoring of rice situation index at arbitrary sites in Japan. However, it is possible to further refine the estimation formula for the rice situation index for early monitoring
19. Ozone - Current Air Quality Index
Science.gov (United States)
... more announcements Air Quality Basics Air Quality Index | Ozone | Particle Pollution | Smoke from fires | What You Can ... Partners Kids Movies NAQ Conferences NOAA Older Adults Ozone Particle Pollution (PM2.5, PM10) Publications Publicaciones (En ...
20. Introduction to indexing and abstracting
CERN Document Server
Cleveland, Ana
2013-01-01
Successful information access in the digital information age requires robust systems of indexing and abstracting. This book provides a complete introduction to the subject that covers the many recent changes in the field.
1. Region 9 - Social Vulnerability Index
Data.gov (United States)
U.S. Environmental Protection Agency — The Social Vulnerability Index is derived from the 2000 US Census data. The fields included are percent minority, median household income, age (under 18 and over...
2. French Basic Course. Grammatical Index.
Science.gov (United States)
Defense Language Inst., Monterey, CA.
This index is intended for use with Volumes 1 through 8 of the French Basic Course. It facilitates the finding of grammatical references in those volumes. The items are cross-referenced and arranged in alphabetical order. (Author/AMH)
3. The Callias index formula revisited
CERN Document Server
Gesztesy, Fritz
2016-01-01
These lecture notes aim at providing a purely analytical and accessible proof of the Callias index formula. In various branches of mathematics (particularly, linear and nonlinear partial differential operators, singular integral operators, etc.) and theoretical physics (e.g., nonrelativistic and relativistic quantum mechanics, condensed matter physics, and quantum field theory), there is much interest in computing Fredholm indices of certain linear partial differential operators. In the late 1970’s, Constantine Callias found a formula for the Fredholm index of a particular first-order differential operator (intimately connected to a supersymmetric Dirac-type operator) additively perturbed by a potential, shedding additional light on the Fedosov-Hörmander Index Theorem. As a byproduct of our proof we also offer a glimpse at special non-Fredholm situations employing a generalized Witten index.
4. Allegheny County Map Index Grid
Data.gov (United States)
Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Map Index Sheets from Block and Lot Grid of Property Assessment and based on aerial photography, showing 1983 datum with solid line and NAD 27 with 5 second grid...
5. Firm Sustainability Performance Index Modeling
OpenAIRE
2015-01-01
The main objective of this paper is to bring a model for firm sustainability performance index by applying both classical and Bayesian structural equation modeling (parametric and semi-parametric modeling). Both techniques are considered to the research data collected based on a survey directed to the China, Taiwan, and Malaysia food manufacturing industry. For estimating firm sustainability performance index we consider three main indicators include knowledge management, organizational learn...
6. A General Interindustry Relatedness Index
OpenAIRE
David J. Bryce; Winter, Sidney G.
2009-01-01
For empirical work in the resource-based view of the firm, characterizing the resources that are responsible for firm growth is difficult because valuable resources are often tacit, ambiguous, or difficult to identify. This is a particular problem for empirical assessments that rely upon the concept of relatedness between resources to characterize the direction of growth of the firm. We tackle the problem for the general case by developing a general interindustry relatedness index. The index ...
7. Occupational risk index of pneumoconiosis
OpenAIRE
Liu, Linjun; 劉林均
2014-01-01
Purpose Pneumoconiosis is a kind of diffuse lung fibrosis disease caused by long-term inhalation of industrial dust and retention in the lungs. In recent years, the incidence of pneumoconiosis decline in Europe, America and other developed countries, but remains stubbornly high in China, and even shows a rising trend. Currently, China does not have a comprehensive pneumoconiosis risk index system for risk assessment. This project aims to review methods to construct the risk index system o...
8. 1999 who's who category index
International Nuclear Information System (INIS)
A classified index and alphabetical directory of Canadian corporate entities involved in the production, manufacturing, conversion, service, retail sales, research and development, transportation, insurance, legal and communications aspects of propane in Canada is provided. The alphabetical directory section provides the usual business information (name, postal address, phone, fax, e-mail and Internet addresses), names of principal officers, affiliations, products or services produced or marketed, and the category under which the company is listed in the classified index
9. Ultraviolet light induced refractive index structures in germanosilica
DEFF Research Database (Denmark)
Svalgaard, Mikael
1997-01-01
bulk optics. Finally, I have developed a new method for direct UV writing of planar waveguide devices using a focussed continuous wave UV laser beam which is scanned across a photosensitive thin film deposited on a silicon wafer. Contrary to other waveguide fabrication techniques this method requires...... application of a scanning near-field optical microscope to obtain high resolution images of UV induced refractive index structures and by monitoring the dynamics of UV induced index changes and luminescence. During part of my ph.d. project I have worked at the National Institute of Standards and Technolgy in...
10. Index effects: Evidence from Australia
Directory of Open Access Journals (Sweden)
Zhao R
2016-04-01
Full Text Available This paper presents the findings of the first study of the index effects from changes in the composition of Australia’s tradeable benchmark index: the S&P/ASX 200. Prior to the introduction of the S&P/ASX200 changes to the composition of the market’s (then benchmark index (the All Ordinaries Index became evident before the formal announcement dates and the changes were made the following trading day. These announcement arrangements enabled profitable front-running trading. Along with the introduction of the new indices (including the S&P/ASX200 the arrangements for announcing changes to the composition of the index were changed to remove the opportunity for profitable frontrunning trading. While this objective was largely met for additions to the index the study found statistically significant evidence of price pressure between the announcement and implementation dates which were partially offset over the subsequent 20-day period. In relation to deletions the study found negative abnormal returns prior to announcement dates as well as between the announcement and implementation dates that were partially reversed over the subsequent 20-day period. The overall conclusion is that the event of changes in the composition of the S&P/ASX200 is on average associated with positive abnormal returns for additions and negative abnormal returns for deletions.
11. Tei index for right ventricular function monitoring in pregnant women complicated with cardiac disease and pulmonary hypertension%Tei指数在监测妊娠合并心脏病伴肺动脉高压患者右心室功能中的作用
Institute of Scientific and Technical Information of China (English)
张志玲; 林建华; 陶如琦
2009-01-01
Objective To investigate clinical value of Tei index used for monitoring right ventricular (RV) function in pregnant women complicating cardiac disease accompanying pulmonary hypertension(PH) and the influence on left ventricular(LV) function due to overload pressure of RV. Methods Fifty-eight pregnant women complicating cardiac disease (including 32 cases with congenital heart disease,14 cases with rheumatic heart disease and 8 cases with arrhythmia)were enrolled in this study, among 26 cases coexisted with pulmonary hypertension. According to the pressure of PH, those patients were divided into three groups:11 cases in mild group[30-49 mm Hg (1 mm Hg=0.133 kPa)],9 cases in moderate group (50-79 mm Hg)and 6 cases in severe group (≥80 mm Hg). In the mean time, 15 healthy pregnant women were matched as control. Tei index were measured for LV and RV respectively. Results (1) The isovolumetric relaxation time [IRT,(93±52) ms] and isovolumetric contraction time [ICT,(66±41) ms] of RV in PH group were significantly higher than normal controls [(39±19) ms in IRT and (38±20) ms in ICT] and the other patients without PH group[(59±12) ms in IRT and (43±19)ms in ICT, P0.01),肺动脉高压组左心室ET为[(202±26)ms]短于对照组[(290±21)ms]和非肺动脉高压组[(220±36)ms],差异有统计学意义(P<0.05,P<0.05);肺动脉高压组左心室Tei指数(0.77±0.38)明显高于对照组(0.43±0.15)和非肺动脉高压组(0.58±0.21),差异也有统计学意义(P<0.01,P<0.05).(3) 右心室Tei指数与肺动脉收缩压具显著正相关关系(r=0.84,P<0.01).(4)肺动脉高压组中,重度患者右心室Tei指数(0.75±0.43)较轻度患者(0.68±0.35)明显升高,差异有统计学意义(P<0.01),较中度患者(0.71±0.14)也明显升高(P<0.05). 结论(1)Tei指数是评价妊娠合并心脏病伴肺动脉高压患者右心室功能简便而准确的多普勒超声新指标,并且Tei指数高低可反映疾病的严重程度;(2)右心室压力负荷增加对左心室功能有明显影响.
12. Impact coverage of the success-index
OpenAIRE
Egghe, Leo
2014-01-01
We show mathematically that the success-index can be any of the following impact indices, dependent on the value of the threshold used in the definition of the success-index: Hirsch-index (h-index), g-index, generalized Wu- and Kosmulski-indices, the average.
13. An automated fog monitoring system for the Indo-Gangetic Plains based on satellite measurements
Science.gov (United States)
Patil, Dinesh; Chourey, Reema; Rizvi, Sarwar; Singh, Manoj; Gautam, Ritesh
2016-05-01
Fog is a meteorological phenomenon that causes reduction in regional visibility and affects air quality, thus leading to various societal and economic implications, especially disrupting air and rail transportation. The persistent and widespread winter fog impacts the entire the Indo-Gangetic Plains (IGP), as frequently observed in satellite imagery. The IGP is a densely populated region in south Asia, inhabiting about 1/6th of the world's population, with a strong upward pollution trend. In this study, we have used multi-spectral radiances and aerosol/cloud retrievals from Terra/Aqua MODIS data for developing an automated web-based fog monitoring system over the IGP. Using our previous and existing methodologies, and ongoing algorithm development for the detection of fog and retrieval of associated microphysical properties (e.g. fog droplet effective radius), we characterize the widespread fog detection during both daytime and nighttime. Specifically, for the night time fog detection, the algorithm employs a satellite-based bi-spectral brightness temperature difference technique between two spectral channels: MODIS band-22 (3.9μm) and band-31 (10.75μm). Further, we are extending our algorithm development to geostationary satellites, for providing continuous monitoring of the spatial-temporal variation of fog. We anticipate that the ongoing and future development of a fog monitoring system would be of assistance to air, rail and vehicular transportation management, as well as for dissemination of fog information to government agencies and general public. The outputs of fog detection algorithm and related aerosol/cloud parameters are operationally disseminated via http://fogsouthasia.com/.
14. Dynamical measurement of refractive index distribution using digital holographic interferometry based on total internal reflection.
Science.gov (United States)
Zhang, Jiwei; Di, Jianglei; Li, Ying; Xi, Teli; Zhao, Jianlin
2015-10-19
We present a method for dynamically measuring the refractive index distribution in a large range based on the combination of digital holographic interferometry and total internal reflection. A series of holograms, carrying the index information of mixed liquids adhered on a total reflection prism surface, are recorded with CCD during the diffusion process. Phase shift differences of the reflected light are reconstructed exploiting the principle of double-exposure holographic interferometry. According to the relationship between the reflection phase shift difference and the liquid index, two dimensional index distributions can be directly figured out, assuming that the index of air near the prism surface is constant. The proposed method can also be applied to measure the index of solid media and monitor the index variation during some chemical reaction processes. PMID:26480394
15. Computerized index for teaching files
International Nuclear Information System (INIS)
A computerized index can be used to retrieve cases from a teaching file that have radiographic findings similar to an unknown case. The probability that a user will review cases with a correct diagnosis was estimated with use of radiographic findings of arthritis in hand radiographs of 110 cases from a teaching file. The nearest-neighbor classification algorithm was used as a computer index to 110 cases of arthritis. Each case was treated as an unknown and inputted to the computer index. The accuracy of the computer index in retrieving cases with the same diagnosis (including rheumatoid arthritis, gout, psoriatic arthritis, inflammatory osteoarthritis, and pyrophosphate arthropathy) was measured. A Bayes classifier algorithm was also tested on the same database. Results are presented. The nearest-neighbor algorithm was 83%. By comparison, the estimated accuracy of the Bayes classifier algorithm was 78%. Conclusions: A computerized index to a teaching file based on the nearest-neighbor algorithm should allow the user to review cases with the correct diagnosis of an unknown case, by entering the findings of the unknown case
16. Energetic consumption levels and human development indexes
International Nuclear Information System (INIS)
The article overviews the energetic consumption levels and human development indexes. The human development indexes are described based on the United Nations Development Programme. A comparison between the energetic consumption levels and human development indexes is also presented
17. Indexes to Nuclear Regulatory Commission Issuances
International Nuclear Information System (INIS)
Digests and indexes for issuances of the Commission (CLI), the Atomic Safety and licensing Board Panel (LBP), the Administrative Law Judges (ALJ) the Directors' Decisions (DD), and the Decisions on Petitions for Rulemaking (DPRM) are presented in this document. These digests and indexes are intended to serve as a guide to the issuances. Information elements are displayed in one or more of five separate formats arranged as follows: Case Name Index; Headers and Digests; Legal Citations Index; Subject Index; and Facility Index
18. Indexes to Nuclear Regulatory Commission Issuances
Energy Technology Data Exchange (ETDEWEB)
NONE
1996-12-31
Digests and indexes for issuances of the Commission (CLI), the Atomic Safety and licensing Board Panel (LBP), the Administrative Law Judges (ALJ) the Directors Decisions (DD), and the Decisions on Petitions for Rulemaking (DPRM) are presented in this document. These digests and indexes are intended to serve as a guide to the issuances. Information elements are displayed in one or more of five separate formats arranged as follows: Case Name Index; Headers and Digests; Legal Citations Index; Subject Index; and Facility Index.
19. Indexing from thesauri to the semantic web
CERN Document Server
de Keyser, Piet
2012-01-01
Indexing consists of both novel and more traditional techniques. Cutting-edge indexing techniques, such as automatic indexing, ontologies, and topic maps, were developed independently of older techniques such as thesauri, but it is now recognized that these older methods also hold expertise. Indexing describes various traditional and novel indexing techniques, giving information professionals and students of library and information sciences a broad and comprehensible introduction to indexing. This title consists of twelve chapters: an Introduction to subject readings and theasauri; Automatic i
20. A Multivariate Process Capability Index
Institute of Scientific and Technical Information of China (English)
WANG Shaoxi; JIA Xinzhang; JIAO Huifang; BIAN Yingchao; SONG Ning; ZHAO Luyu; WEN Xin
2006-01-01
Process capability indices have been widely used in the manufacturing industry, providing numerical measures on process precision, process accuracy, and process performance. Capability measures for processes with a single characteristic have been investigated extensively. However, capability measures for processes with multiple characteristics are comparatively neglected. In this paper, inspired by the approach and model of process capability index investigated by K.S.Chen et al.(2003) and A.B.Yeh et al.(1998), a note model of multivariate process capability index based on non-conformity is presented. As for this index, the data of each single characteristic don't require satisfying normal distribution, of which its computing is simple and particioners will not fell too theoretical. At last the application analysis is made.
1. Socializing the h-index
CERN Document Server
Cormode, Graham; Muthukrishnan, S; Thompson, Brian
2012-01-01
A variety of bibliometric measures have been proposed to quantify the impact of researchers and their work. The h-index is a notable and widely-used example which aims to improve over simple metrics such as raw counts of papers or citations. However, a limitation of this measure is that it considers authors in isolation and does not account for contributions through a collaborative team. To address this, we propose a natural variant that we dub the Social h-index. The idea is to redistribute the h-index score to reflect an individual's impact on the research community. In addition to describing this new measure, we provide examples, discuss its properties, and contrast with other measures.
2. Witten Index for Noncompact Dynamics
CERN Document Server
Lee, Seung-Joo
2016-01-01
Among gauged dynamics motivated by string theory, we find many with gapless asymptotic directions. Although the natural boundary condition for ground states is $L^2$, one often turns on chemical potentials or supersymmetric mass terms to regulate the infrared issues, instead, and computes the twisted partition function. We point out how this procedure generically fails to capture physical $L^2$ Witten index with often misleading results. We also explore how, nevertheless, the Witten index is sometimes intricately embedded in such twisted partition functions. For $d=1$ theories with gapless continuum sector from gauge multiplets, such as non-primitive quivers and pure Yang-Mills, a further subtlety exists, leading to fractional expressions. Quite unexpectedly, however, the integral $L^2$ Witten index can be extracted directly and easily from the twisted partition function of such theories. This phenomenon is tied to the notion of the rational invariant that appears naturally in the wall-crossing formulae, and ...
3. A new method for calculation of an air quality index
Energy Technology Data Exchange (ETDEWEB)
Ilvessalo, P. [Finnish Meteorological Inst., Helsinki (Finland). Air Quality Dept.
1995-12-31
Air quality measurement programs in Finnish towns have expanded during the last few years. As a result of this it is more and more difficult to make use of all the measured concentration data. Citizens of Finnish towns are nowadays taking more of an interest in the air quality of their surroundings. The need to describe air quality in a simplified form has increased. Air quality indices permit the presentation of air quality data in such a way that prevailing conditions are more easily understandable than when using concentration data as such. Using an air quality index always means that some of the information about concentrations of contaminants in the air will be lost. How much information is possible to extract from a single index number depends on the calculation method. A new method for the calculation of an air quality index has been developed. This index always indicates the overstepping of an air quality guideline level. The calculation of this air quality index is performed using the concentrations of all the contaminants measured. The index gives information both about the prevailing air quality and also the short-term trend. It can also warn about the expected exceeding of guidelines due to one or several contaminants. The new index is especially suitable for the real-time monitoring and notification of air quality values. The behaviour of the index was studied using material from a measurement period in the spring of 1994 in Kaepylae, Helsinki. Material from a pre-operational period in the town of Oulu was also available. (author)
4. Venture Capital Industry Index Portfolio Analysis
Directory of Open Access Journals (Sweden)
Dagang Yang
2013-05-01
Full Text Available This paper using index analysis method, knowledge of venture capital as well as index funds investment ideas, successively set up the Markowitz model and the single index model of index investing. Markowitz model for the calculation of the risk of workload is too big and single-index model although accuracy is slightly lower, but can certainly be very well used in practice. Therefore, We use index invest to invest in Shanghai 10 index securities with the single-index model , and apply lingo software to figure out the venture capital portfolio which have different yields.
5. Treaty Monitoring
DEFF Research Database (Denmark)
Canty, M.; Jasani, B.; Lingenfelder, I.;
2009-01-01
remote sensing technologies. The book therefore comprises management aspects (issues and priorities of security research, crisis response), applied methodologies and process chains (treaty monitoring, estimation of population densities and characteristics, border permeability models, damage assessment...
6. Monitoring coolant
International Nuclear Information System (INIS)
In a system for monitoring coolant conditions within a pressurized vessel, a length of tubing extends outward from the vessel from an open end containing a first liner restriction at the location to be monitored. The flowing fluid is cooled and condensed before passing through a second line restriction. Measurement of pressure drop at the second line restriction gives an indication of fluid condition at the first line restriction. Multiple lengths of tubing with open ends at incremental elevations can measure coolant level within the vessel. The system may monitor the coolant level within the vessel and also provide measurement of the gaseous phase material at the monitored location and of the temperature of the liquid coolant or of superheated vapors. (author)
CERN Document Server
Singh, Gurmukh
2015-01-01
This book is useful for Hadoop administrators who need to learn how to monitor and diagnose their clusters. Also, the book will prove useful for new users of the technology, as the language used is simple and easy to grasp.
8. Detection of respiratory compromise by acoustic monitoring, capnography, and brain function monitoring during monitored anesthesia care.
Science.gov (United States)
Tanaka, Pedro P; Tanaka, Maria; Drover, David R
2014-12-01
Episodes of apnea in sedated patients represent a risk of respiratory compromise. We hypothesized that acoustic monitoring would be equivalent to capnography for detection of respiratory pauses, with fewer false alarms. In addition, we hypothesized that the patient state index (PSI) would be correlated with the frequency of respiratory pauses and therefore could provide information about the risk of apnea during sedation. Patients undergoing sedation for surgical procedures were monitored for respiration rate using acoustic monitoring and capnography and for depth of sedation using the PSI. A clinician blinded to the acoustic and sedation monitor observed the capnograph and patient to assess sedation and episodes of apnea. Another clinician retrospectively reviewed the capnography and acoustic waveform and sound files to identify true positive and false positive respiratory pauses by each method (reference method). Sensitivity, specificity, and likelihood ratio for detection of respiratory pause was calculated for acoustic monitoring and capnography. The correlation of PSI with respiratory pause events was determined. For the 51 respiratory pauses validated by retrospective analysis, the sensitivity, specificity, and likelihood ratio positive for detection were 16, 96 %, and 3.5 for clinician observation; 88, 7 %, and 1.0 for capnography; and 55, 87 %, and 4.1 for acoustic monitoring. There was no correlation between PSI and respiratory pause events. Acoustic monitoring had the highest likelihood ratio positive for detection of respiratory pause events compared with capnography and clinician observation and, therefore, may provide the best method for respiration rate monitoring during these procedures. PMID:24420342
9. Modified Palmer Drought Severity Index Based on Distributed Hydrological Simulation
OpenAIRE
Denghua Yan; Xiaoliang Shi; Zhiyong Yang; Ying Li; Kai Zhao; Yong Yuan
2013-01-01
Drought monitoring at large scale is essential for fighting against drought. Aiming at the limitation of acquiring long-time serial soil moisture and actual evapotranspiration for Palmer drought severity index (PDSI), the paper modified the PDSI based on distributed hydrological model on subbasin level in Luanhe river basin, North China. The water balance was simulated using the Soil and Water Assessment Tool (SWAT). Calibration and validation results showed good agreement between simulated a...
10. WATER QUALITY INDEX – AN INSTRUMENT FOR WATER RESOURCES MANAGEMENT
OpenAIRE
PAIU MĂDĂLINA; BREABĂN IULIANA GABRIELA
2014-01-01
Water quality status assessment can be defined as the evaluation of physical, chemical, biological state of the water in relation with the natural state, anthropogenic effects and future uses. Water quality index reduces the number of parameters used in monitoring water quality to a simple expression in order to facilitate interpretation of the data, allowing public access to water quality data. This study is a summary of an interdisciplinary research program on surface water quality monit...
11. Soil Quality Indexing Strategies for Evaluating Sugarcane Expansion in Brazil
OpenAIRE
Cherubin, Maurício R.; Douglas L. Karlen; Cerri, Carlos E. P.; Franco, André L. C.; Tormena, Cássio A.; Davies, Christian A.; Cerri, Carlos C.
2016-01-01
Increasing demand for biofuel has intensified land-use change (LUC) for sugarcane (Saccharum officinarum) expansion in Brazil. Assessments of soil quality (SQ) response to this LUC are essential for quantifying and monitoring sustainability of sugarcane production over time. Since there is not a universal methodology for assessing SQ, we conducted a field-study at three sites within the largest sugarcane-producing region of Brazil to develop a SQ index (SQI). The most common LUC scenario (i.e...
12. The Powerdomain of Indexed Valuations
DEFF Research Database (Denmark)
Varacca, Daniele
2002-01-01
This paper is about combining nondeterminism and probabilities. We study this phenomenon from a domain theoretic point of view. In domain theory, nondeterminism is modeled using the notion of powerdomain, while probability is modeled using the powerdomain of valuations. Those two functors do not...... combine well, as they are. We define the notion of powerdomain of indexed valuations, which can be combined nicely with the usual nondeterministic powerdomain. We show an equational characterization of our construction. Finally we discuss the computational meaning of indexed valuations, and we show how...
13. Complexity of Finding Alphabet Indexing
OpenAIRE
Shimozono, Shinichi; Miyano, Satoru
1992-01-01
For two finite disjoint sets $P$ and $Q$ of strings over an alphabet $sum$, an alphabet indexing $psi$ for $P,Q$ by an indexing alphabet $Gamma$ with $mid Gamma mid < mid sum mid is a mapping$psi : sum \\to Gamma$satisfying$\\tilde{psi}(P) cap \\tilde{psi}(Q) = emptyset$, where$\\tilde{psi} : sum^* \\to Gamma^*$is the homomorphism derived from$psi$. We defined this notion through experiments of knowledge acquisition from amino acid sequences of proteins by learning algorithms. This paper an... 14. Building A Venture Capital Index OpenAIRE Liang Peng 2001-01-01 This paper builds a venture capital index from 1987 to 1999 that consists of 12,946 rounds of venture financing with 5,643 venture-backed firms. The paper uses two innovative techniques, a re-weighting procedure and a method of moment repeat sales regression, to mitigates three problems - missing data, censored data, and sample selection. We report the time series of capital flows, net asset value, and returns of the venture capital index. We find that the venture capital industry experienced... 15. Treaty Monitoring DEFF Research Database (Denmark) Canty, M.; Jasani, B.; Lingenfelder, I.; Nielsen, Allan Aasbjerg; Niemeyer, I.; Nussbaum, S.; Schlittenhardt, J.; Shimoni, M.; Skriver, Henning remote sensing technologies. The book therefore comprises management aspects (issues and priorities of security research, crisis response), applied methodologies and process chains (treaty monitoring, estimation of population densities and characteristics, border permeability models, damage assessment...... private companies, national research institutions and international organizations, all of whom were brought together under the aegis of the European research project GMOSS (Global Monitoring for Security and Stability). This book is tailored for the scientific community that deals with the application of... 16. Bayesian Monitoring. OpenAIRE Kirstein, Roland 2005-01-01 This paper presents a modification of the inspection game: The ?Bayesian Monitoring? model rests on the assumption that judges are interested in enforcing compliant behavior and making correct decisions. They may base their judgements on an informative but imperfect signal which can be generated costlessly. In the original inspection game, monitoring is costly and generates a perfectly informative signal. While the inspection game has only one mixed strategy equilibrium, three Perfect Bayesia... 17. Index Directory of Open Access Journals (Sweden) Antonio Juan SÁNCHEZ 2013-05-01 Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas. The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society. We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful. 18. Index Directory of Open Access Journals (Sweden) Antonio Juan Sánchez 2012-09-01 Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ISSN: 2255-2863 is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence, and their application in different areas. The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society. 19. Index Directory of Open Access Journals (Sweden) Antonio Juan Sánchez 2013-08-01 Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas.The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful. 20. Index OpenAIRE --, -- 2015-01-01 Doç. Dr. İshak Emin Aktepe (Erzincan Üniversitesi) Doç. Dr. İsmail Sağlam (Uludağ Üniversitesi) Doç. Dr. Mehmet Boynukalın (Şehir Üniversitesi) Doç. Dr. Mustafa Macit (Atatürk Üniversitesi) Doç. Dr. Nuh Arslantaş (Marmara Üniversitesi) Doç. Dr. Osman Güman (Sakarya Üniversitesi) Doç. Dr. Tuncay Başoğlu (İSAM) Doç. Dr. Yusuf Alemdar (Bülent Ecevit Üniversitesi) Doç. Dr. Celil Kiraz (Uludağ Üniversitesi) Yrd. Doç. Dr. Ali Hakan Çavuşoğlu (29 Mayıs Üniversitesi) Yrd. Doç. Dr. Ali Bulut... 1. Index Directory of Open Access Journals (Sweden) Antonio Juan Sánchez 2013-11-01 Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas.The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful. 2. Index Directory of Open Access Journals (Sweden) Antonio Juan SÁNCHEZ 2012-07-01 Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas.The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful. 3. Developing an operational rangeland water requirement satisfaction index Science.gov (United States) Senay, G.B.; Verdin, J.P.; Rowland, J. 2011-01-01 Developing an operational water requirement satisfaction index (WRSI) for range-land monitoring is an important goal of the famine early warning systems network. An operational WRSI has been developed for crop monitoring, but until recently a comparable WRSI for rangeland was not successful because of the extremely poor performance of the index when based on published crop coefficients (Kc) for rangelands. To improve the rangeland WRSI, we developed a simple calibration technique that adjusts the Kc values for rangeland monitoring using long-term rainfall distribution and reference evapotranspiration data. The premise for adjusting the Kc values is based on the assumption that a viable rangeland should exhibit above-average WRSI (values >80%) during a normal year. The normal year was represented by a median dekadal rainfall distribution (satellite rainfall estimate from 1996 to 2006). Similarly, a long-term average for potential evapotranspiration was used as input to the famine early warning systems network WRSI model in combination with soil-water-holding capacity data. A dekadal rangeland WRSI has been operational for east and west Africa since 2005. User feedback has been encouraging, especially with regard to the end-of-season WRSI anomaly products that compare the index's performance to 'normal' years. Currently, rangeland WRSI products are generated on a dekadal basis and posted for free distribution on the US Geological Survey early warning website at http://earlywarning.usgs.gov/adds/. 4. Transportation Environment Data Bank index Energy Technology Data Exchange (ETDEWEB) Davidson, C.A.; Foley, J.T. 1976-11-01 In an effort to determine the environment intensities to which energy materials in transit will be exposed, a ''Data Bank'' of environmental information has been established by Sandia Laboratories, Division 1285 for the ERDA Division of Environmental Control Technology. This document is an index which can be used to request data of interest. 5. Transportation Environment Data Bank index Energy Technology Data Exchange (ETDEWEB) Davidson, C.A.; Foley, J.T. 1977-04-01 In an effort to determine the environment intensities to which energy materials in transit will be exposed, a ''Data Bank'' of environmental information has been established by Sandia Laboratories, Division 1285 for the ERDA Division of Environmental Control Technology. This document is an index which can be used to request data of interest. 6. Transportation Environment Data Bank index International Nuclear Information System (INIS) In an effort to determine the environment intensities to which energy materials in transit will be exposed, a ''Data Bank'' of environmental information has been established by Sandia Laboratories, Division 1285 for the ERDA Division of Environmental Control Technology. This document is an index which can be used to request data of interest 7. 1988 Bulletin compilation and index Energy Technology Data Exchange (ETDEWEB) NONE 1989-02-01 This document is published to provide current information about the national program for managing spent fuel and high-level radioactive waste. This document is a compilation of issues from the 1988 calendar year. A table of contents and one index have been provided to assist in finding information. 8. Automatic indexing, compiling and classification International Nuclear Information System (INIS) A review of the principles of automatic indexing, is followed by a comparison and summing-up of work by the authors and by a Soviet staff from the Moscou INFORM-ELECTRO Institute. The mathematical and linguistic problems of the automatic building of thesaurus and automatic classification are examined 9. Asymptotics for the Hirsch Index NARCIS (Netherlands) Beirlant, J.; Einmahl, J.H.J. 2007-01-01 The last decade methods for quantifying the research output of individual researchers have become quite popular in academic policy making. The h- index (Hirsch, 2005) constitutes an interesting quality measure that has attracted a lot of attention recently. It is now a standard measure available for 10. USGS 1-min Dst index Science.gov (United States) Gannon, J.L.; Love, J.J. 2011-01-01 We produce a 1-min time resolution storm-time disturbance index, the USGS Dst, called Dst8507-4SM. This index is based on minute resolution horizontal magnetic field intensity from low-latitude observatories in Honolulu, Kakioka, San Juan and Hermanus, for the years 1985-2007. The method used to produce the index uses a combination of time- and frequency-domain techniques, which more clearly identifies and excises solar-quiet variation from the horizontal intensity time series of an individual station than the strictly time-domain method used in the Kyoto Dst index. The USGS 1-min Dst is compared against the Kyoto Dst, Kyoto Sym-H, and the USGS 1-h Dst (Dst5807-4SH). In a time series comparison, Sym-H is found to produce more extreme values during both sudden impulses and main phase maximum deviation, possibly due to the latitude of its contributing observatories. Both Kyoto indices are shown to have a peak in their distributions below zero, while the USGS indices have a peak near zero. The USGS 1-min Dst is shown to have the higher time resolution benefits of Sym-H, while using the more typical low-latitude observatories of Kyoto Dst. ?? 2010. 11. Index to AEC Information Booklets Energy Technology Data Exchange (ETDEWEB) None 1978-01-01 The U. S. Atomic Energy Commission publishes a series of information booklets for the general public. These booklets explain many aspects of nuclear science. Because these booklets cover such a variety of scientific fields, this index was prepared to help the reader find quickly those booklets that contain the information he needs. 12. An automatic bibliography indexing programme Directory of Open Access Journals (Sweden) J. W. Morris 1974-12-01 Full Text Available A relatively simple FORTRAN IV programme, designed for a small computer, for author and key-word indexes to bibliographic records is described, and examples of output are given. It is compared with some other systems. Suggested improvements to the programme are given. 13. Index of competences Advanced Materials International Nuclear Information System (INIS) This index gathers the main french competences in advanced materials field (university laboratories, research and development organisms, technical centers, experts...). The concerned advanced materials are plastics and technical polymers, metals and alloys, composite materials, technical ceramics, glasses, paper, wood and textile. A PC computer version is also available. (A.B.) 14. The Global Creativity Index 2015 OpenAIRE Florida, Richard; Mellander, Charlotta; King, Karen 2015-01-01 This report presents the 2015 edition of the Global Creativity Index, or GCI. The GCI is a broad-based measure for advanced economic growth and sustainable prosperity based on the 3Ts of economic development—talent, technology, and tolerance. It rates and ranks 139 nations worldwide on each of these dimensions and on our overall measure of creativity and prosperity. 15. Witten index for noncompact dynamics Science.gov (United States) Lee, Seung-Joo; Yi, Piljin 2016-06-01 Among gauged dynamics motivated by string theory, we find many with gapless asymptotic directions. Although the natural boundary condition for ground states is L 2, one often turns on chemical potentials or supersymmetric mass terms to regulate the infrared issues, instead, and computes the twisted partition function. We point out how this procedure generically fails to capture physical L 2 Witten index with often misleading results. We also explore how, nevertheless, the Witten index is sometimes intricately embedded in such twisted partition functions. For d = 1 theories with gapless continuum sector from gauge multiplets, such as non-primitive quivers and pure Yang-Mills, a further subtlety exists, leading to fractional expressions. Quite unexpectedly, however, the integral L 2 Witten index can be extracted directly and easily from the twisted partition function of such theories. This phenomenon is tied to the notion of the rational invariant that appears naturally in the wall-crossing formulae, and offers a general mechanism of reading off Witten index directly from the twisted partition function. Along the way, we correct early numerical results for some of mathcal{N} = 4 , 8 , 16 pure Yang-Mills quantum mechanics, and count threshold bound states for general gauge groups beyond SU( N ). 16. Mining and Indexing Graph Databases Science.gov (United States) Yuan, Dayu 2013-01-01 Graphs are widely used to model structures and relationships of objects in various scientific and commercial fields. Chemical molecules, proteins, malware system-call dependencies and three-dimensional mechanical parts are all modeled as graphs. In this dissertation, we propose to mine and index those graph data to enable fast and scalable search.… 17. 1988 Bulletin compilation and index International Nuclear Information System (INIS) This document is published to provide current information about the national program for managing spent fuel and high-level radioactive waste. This document is a compilation of issues from the 1988 calendar year. A table of contents and one index have been provided to assist in finding information 18. Diffusion Indexes with Sparse Loadings DEFF Research Database (Denmark) Kristensen, Johannes Tang approach to the problem by using the LASSO as a variable selection method to choose between the possible variables and thus obtain sparse loadings from which factors or diffusion indexes can be formed. This allows us to build a more parsimonious factor model which is better suited for forecasting compared... 19. The weighted vertex PI index CERN Document Server c, Aleksandar Ili\\' 2011-01-01 The vertex PI index is a distance--based molecular structure descriptor, that recently found numerous chemical applications. In order to increase diversity of this topological index for bipartite graphs, we introduce weighted version defined as$PI_w (G) = \\sum_{e = uv \\in E} (deg (u) + deg (v)) (n_u (e) + n_v (e))$, where$deg (u)$denotes the vertex degree of$u$and$n_u (e)$denotes the number of vertices of$G$whose distance to the vertex$u$is smaller than the distance to the vertex$v$. We establish basic properties of$PI_w (G)$, and prove various lower and upper bounds. In particular, the path$P_n$has minimal, while the complete tripartite graph$K_{n/3, n/3, n/3}$has maximal weighed vertex$PI$index among graphs with$n$vertices. We also compute exact expressions for the weighted vertex PI index of the Cartesian product of graphs. Finally we present modifications of two inequalities and open new perspectives for the future research. 20. Human development index: a critique. Science.gov (United States) Chowdhury, O H 1991-09-01 This discussion focuses on the advantages and disadvantages of constructing a summary measure of the multidimensional and dynamic concept of development. 2 indexes are referred to: the UN Development Programme; human development index (HDI) and the Physical Quality of Life Index (PQLI). PQLI weights equally life expectancy at 1 year, infant mortality, and literacy, regardless of the correlation of variables and the arbitrariness of the weights. PQLI also is assumed to measure the quantity of life, not the quality. HDI measures quantity and quality and includes life expectancy, literacy, and real GDP/capita, and may include a measure of human freedom. Objectivity is a major problem with any index. Assignment of weights is an example of arbitrariness without justification and the index is sensitive the weights assigned. There is a paradox between defending weights on the 1 hand and, if robustness of the index is assumed and components are correlated, then any single component could suffice. A more serious criticism of the HDI is the weighting of each rank order of the country by 1/3 and summing the weighted ranking of the 3 indicators. The flaw here is the problem of application of ratio scales on ordinal magnitudes. The rank correlation coefficient between real GDP/capita and life expectancy, real GDP/capita and literacy; and literacy and life expectancy are .90, .80, and .89, respectively. HDI is also correlated with GDP/capita (.87). Composite indexes are not sensitive to variability in components or the imbalance in components, e.g., a country with low means but high literacy. The goal should continue to be to develop a conceptually and methodologically acceptable summary measure. It is suggested that a necessary component is economic development. Countries may be ranked according to their level of economic development in order to measure their achievements in human development. A weighted distribution of income/capita is a better indicator of the economic well 1. Laser schlieren crystal monitor Science.gov (United States) Owen, Robert B. (Inventor); Johnston, Mary H. (Inventor) 1987-01-01 A system and method for monitoring the state of a crystal which is suspended in a solution is described which includes providing a light source for emitting a beam of light along an optical axis. A collimating lens is arranged along the optical axis for collimating the emitted beam to provide a first collimated light beam consisting of parallel light rays. By passing the first collimated light beam through a transparent container, a number of the parallel light rays are deflected off the surfaces of said crystal being monitored according to the refractive index gradient to provide a deflected beam of deflected light rays. A focusing lens is arranged along optical axis for focusing the deflected rays towards a desired focal point. A knife edge is arranged in a predetermined orientation at the focal point; and a screen is provided. A portion of the deflected beam is blocked with the knife edge to project only a portion of the deflected beam. A band is created at one edge of the image of the crystal which indicates the state of change of the surface of the crystal being monitored. 2. Drought index driven by L-band microwave soil moisture data Science.gov (United States) Bitar, Ahmad Al; Kerr, Yann; Merlin, Olivier; Cabot, François; Choné, Audrey; Wigneron, Jean-Pierre 2014-05-01 Drought is considered in many areas across the globe as one of the major extreme events. Studies do not all agree on the increase of the frequency of drought events over the past 60 years [1], but they all agree that the impact of droughts has increased and the need for efficient global monitoring tools has become most than ever urgent. Droughts are monitored through drought indexes, many of which are based on precipitation (Palmer index(s), PDI…), on vegetation status (VDI) or on surface temperatures. They can also be derived from climate prediction models outputs. The GMO has selected the (SPI) Standardized Precipitation Index as the reference index for the monitoring of drought at global scale. The drawback of this index is that it is directly dependent on global precipitation products that are not accurate over global scale. On the other hand, Vegetation based indexes show the a posteriori effect of drought, since they are based on NDVI. In this study, we choose to combine the surface soil moisture from microwave sensor with climate data to access a drought index. The microwave data are considered from the SMOS (Soil Moisture and Ocean Salinity) mission at L-Band (1.4 Ghz) interferometric radiometer from ESA (European Space Agency) [2]. Global surface soil moisture maps with 3 days coverage for ascending 6AM and descending 6PM orbits SMOS have been delivered since January 2010 at a 40 km nominal resolution. We use in this study the daily L3 global soil moisture maps from CATDS (Centre Aval de Traitement des Données SMOS) [3,4]. We present a drought index computed by a double bucket hydrological model driven by operational remote sensing data and ancillary datasets. The SPI is also compared to other drought indicators like vegetation indexes and Palmer drought index. Comparison of drought index to vegetation indexes from AVHRR and MODIS over continental United States show that the drought index can be used as an early warning system for drought monitoring as 3. Area monitoring International Nuclear Information System (INIS) The exposure of individuals to ionizing radiation is normally subject to legal controls which specify limits, and restriction, of doses that both occupational workers and members of the public are exposed to. The dose limits recommended by the International Commission on Radiological Protection (ICRP), and adopted by many countries are specified in terms of body dose equivalents, sometimes referred to as limiting quantities. However these quantities are not measurable since they are defined as average doses in organs and tissues of the human body. Thus for the same physical radiation field the dose delivered to an individual will not have a fixed value but will depend upon each individual's sex, age and physical construction as well as upon their orientation in the field. Ionizing radiation, also, cannot be detected by a person's physical senses of sight, smell, hearing and touch. Thus to control the levels of radiation to which individuals are exposed, special operational quantities are used and quantitative measurements have to be made using personal dosemeters or area monitoring equipment. This report describes the operational quantities that are being increasingly used worldwide for area monitoring. It provides information on the international standards that are available on the performance requirements for monitoring equipment designed to measure these operational quantities. It also reviews the recent international standards that have been published on the calibration and type testing of area monitors and gives an example of legislative requirements on area monitoring equipment. (author) 4. Event Index - a LHCb Event Search System CERN Document Server Ustyuzhanin, Andrey; Kazeev, Nikita; Redkin, Artem 2015-01-01 LHC experiments generate up to$10^{12}events per year. This paper describes Event Index - an event search system. Event Index's primary function is quickly selecting subsets of events from a combination of conditions, such as the estimated decay channel or stripping lines output. Event Index is essentially Apache Lucene optimized for read-only indexes distributed over independent shards on independent nodes. 5. 意识指数监测用于无痛结肠镜检查麻醉中药物应用的指导意义%The instructional significance of monitoring on index of consciousness to the drug application for anaesthetic in the pa-tients checked with painless colonoscopy Institute of Scientific and Technical Information of China (English) 林艳君; 杨晓辉; 杨占民 2015-01-01 Objective To discuss the advantage of index of consciousness (IOC) used in patients undergoing painless colonoscopy. Methods 100 patients aged 18~65 with ASAⅠ~Ⅱwere randomly divided into group A (propofol) and group B (propofol with IOC). Propofol was adjusted by consciousness and hemodynamics in group A,while by IOC and hemodynamics in group B. IOC was controlled at 40~60. The total amount of propofol,the awakening and replying time and adverse reaction were recorded. Results Compared with group A,the total amount of propofol,the awakening and replying time were less or shorter in group B. The occurrence rate of adverse reaction of respiratory depression, nausea and vomiting, bradyrhythmia in group B was lower than group A (P0.05). Conclusion IOC monitoring can reach a more reasonable anesthesia depth with propofol in painless colonoscopy, it can decrease the dose of propofol and adverse reaction, also recover rapidly.%目的：观察意识指数（IOC）用于无痛结肠镜检查麻醉中药物应用的指导意义。方法100例ASAⅠ～Ⅱ级接受无痛结肠镜检查的患者，年龄18~65岁，随机分成2组：单纯异丙酚组（A组）与IOC 监测异丙酚组（B 组），各50例。A 组根据患者意识和血流动力学调整异丙酚用量，B组根据IOC值和血流动力学调整异丙酚用量，检查中维持IOC值40~60。分别记录异丙酚总量、苏醒和应答时间及不良反应情况。结果2组患者均顺利完成检查，与A 组比较，B组的异丙酚总量减少，苏醒和应答时间均缩短（P<0.05）。 B组呼吸抑制、恶心呕吐、心动过缓的不良反应发生率明显低于A组，B组体动发生多于A组，但两组的发生率未见明显统计学差异。结论 IOC监测下异丙酚用于无痛结肠镜检查可以达到更合理的麻醉深度，并减少异丙酚用量，术后恢复快，不良反应少。 6. Regulatory and technical reports (abstract index journal) International Nuclear Information System (INIS) This compilation consists of bibliographic data and abstracts for the formal regulatory and technical reports issued by the US Nuclear Regulatory Commission staff and its contractors. There are four types of reports included: staff reports, conference reports, contractor reports, and international agreement reports. In addition to the main citations with abstracts, the following are also included: Secondary report number index; Personal author index; Subject index; NRC originating organization indices for staff reports and international agreement reports; NRC contract sponsor index; Contractor index; International organization index; and Licensed facility index 7. Fundamentals of database indexing and searching CERN Document Server Bhattacharya, Arnab 2014-01-01 Fundamentals of Database Indexing and Searching presents well-known database searching and indexing techniques. It focuses on similarity search queries, showing how to use distance functions to measure the notion of dissimilarity.After defining database queries and similarity search queries, the book organizes the most common and representative index structures according to their characteristics. The author first describes low-dimensional index structures, memory-based index structures, and hierarchical disk-based index structures. He then outlines useful distance measures and index structures 8. The Biodiversity Informatics Potential Index Directory of Open Access Journals (Sweden) Ariño Arturo H 2011-12-01 Full Text Available Abstract Background Biodiversity informatics is a relatively new discipline extending computer science in the context of biodiversity data, and its development to date has not been uniform throughout the world. Digitizing effort and capacity building are costly, and ways should be found to prioritize them rationally. The proposed 'Biodiversity Informatics Potential (BIP Index' seeks to fulfill such a prioritization role. We propose that the potential for biodiversity informatics be assessed through three concepts: (a the intrinsic biodiversity potential (the biological richness or ecological diversity of a country; (b the capacity of the country to generate biodiversity data records; and (c the availability of technical infrastructure in a country for managing and publishing such records. Methods Broadly, the techniques used to construct the BIP Index were rank correlation, multiple regression analysis, principal components analysis and optimization by linear programming. We built the BIP Index by finding a parsimonious set of country-level human, economic and environmental variables that best predicted the availability of primary biodiversity data accessible through the Global Biodiversity Information Facility (GBIF network, and constructing an optimized model with these variables. The model was then applied to all countries for which sufficient data existed, to obtain a score for each country. Countries were ranked according to that score. Results Many of the current GBIF participants ranked highly in the BIP Index, although some of them seemed not to have realized their biodiversity informatics potential. The BIP Index attributed low ranking to most non-participant countries; however, a few of them scored highly, suggesting that these would be high-return new participants if encouraged to contribute towards the GBIF mission of free and open access to biodiversity data. Conclusions The BIP Index could potentially help in (a identifying 9. Bureau of Radiological Health publications index International Nuclear Information System (INIS) The Key Word in Context (KWIC) index to the publications of the Bureau of Radiological Health was prepared to aid in the retrieval and identification of publications originated or authored by Bureau staff or published by the Bureau. These publications include journal articles, government publications and technical reports, selected staff papers, and Bureau news releases issued by HEW. For convenience, the document is divided into four sections, KWIC Index, Author Index, Bibliography Index, and BRH Publications Subject Index 10. Inverted indexes-Types and techniques OpenAIRE Ajit Kumar Mahapatra; Sitanath Biswas 2011-01-01 There has been a substantial amount of research on high performance inverted index because most web and search engines use an inverted index to execute queries. Documents are normally stored as lists of words, but inverted indexes invert this by storing for each word the list of documents that the word appears in, hence the name "inverted index". This paper presents the crucial research findings on inverted indexes, their types and techniques. 11. Condensed Extended Hyper-Wiener Index Institute of Scientific and Technical Information of China (English) LI Xin-Hua; Abraham F. Jalbout; JI Zhi 2008-01-01 According to the definitions of molecular connectivity and hyper-Wiener index, a novel set of hyper-Wiener indexes (Dn, mDn) were defined and named as condensed extended hyper-Wiener index, the potential usefulness of which in QSAR/QSPR is evaluated by its correlation with a number of C3-C8 alkanes as well as by a favorable comparison with models based on molecular connectivity index and overall Wiener index. 12. The air pollution index system in Hong Kong Energy Technology Data Exchange (ETDEWEB) Lee, F.Y.P.; Gervat, G.P. [Hong Kong Government, Wanchai (Hong Kong). Environmental Protection Dept. 1995-12-31 The Hong Kong Environmental Protection Department (EPD) is currently operating an air quality monitoring network in the territory. There are nine monitoring stations, each with air quality monitoring equipment, meteorological instruments and a data logger. Five minute averaged data are transmitted through telephone lines to the central computer at the EPD Air Laboratory and are also stored in the data logger on site, as backup. At present, the EPD releases its air quality measurements to the public via monthly and special press releases, and annual reports. However, as public awareness of air pollution problems has increased, there has been an urgent need for timely and simpler information about air pollution levels. The development and operation of an Air Pollution Index (API) system has addressed that need. This presentation discusses the API computation, the information and advice released to the general public and how they can access the API information. Some API results are also presented. (author) 13. Research on Monitoring Area Division of Quality Grade Changes in County Cultivated Land and Technology of Deploying Monitoring Point OpenAIRE Wei, Wei; Liao, Lijun; Yu, Jianxin 2013-01-01 It is an important means in management of improving both the quality and quantity of cultivated land to monitor grade changes in cultivated land quality. How to deploy monitoring network system and its point reasonably and roundly are the key to the technology of monitoring grade changes in cultivated land quality by monitoring grade changes in cultivated land quality dynamically in order to obtain the information to the index of cultivated land quality and its changes based on the existing a... 14. Fundamental indexation for bond markets OpenAIRE Marielle de Jong; Hongwen Wu 2014-01-01 Purpose – The purpose of this paper is to build alternative indices weighing using a measure of fundamental value rather than debt size. The official bond indices built to reflect general price trends are market weighted, meaning that the bonds are weighted by their debt size. The more indebted, the more weight in the index, which mechanically increments the investment risks that are inherent. Those market indices are shown to be return-to-risk inefficient in recent studies compared to indice... 15. Body Mass Index and Stroke DEFF Research Database (Denmark) Andersen, Klaus Kaae; Olsen, Tom Skyhøj 2013-01-01 Although obesity is associated with excess mortality and morbidity, mortality is lower in obese than in normal weight stroke patients (the obesity paradox). Studies now indicate that obesity is not associated with increased risk of recurrent stroke in the years after first stroke. We studied the ...... the association between body mass index (BMI) and stroke patient's risk of having a history of previous stroke (recurrent stroke).... 16. Video OCR for Video Indexing OpenAIRE S., Sankirti; Kamade, P. M. 2011-01-01 Video OCR is a technique that can greatly help to locate the topics of interest in video via the automatic extraction and reading of captions and annotations. Text in video can provide key indexing information. Recognizing such text for search application is critical. Major difficult problem for character recognition for videos is degraded and deformated characters, low resolution characters or very complex background. To tackle the problem preprocessing on text image plays vital role. Most o... 17. Insurance Against Covariate Shocks : The Role of Index-Based Insurance in Social Protection in Low-Income Countries of Africa OpenAIRE Alderman, Harold; Haque, Trina 2007-01-01 Index insurance, such as weather indexing, addresses other inherent problems in insurance by using an indicator that is not affected by individual behavior and may address monitoring costs and moral hazard. A number of innovations using index insurance are being tried currently in diverse settings ranging from India to Mongolia to Malawi. Marketing costs may limit the provision of such ins... 18. Generic communications index: User's manual International Nuclear Information System (INIS) This report is a manual for providing information required to use a special computer program developed by the NRC for indexing generic communications. The program is written in a user-friendly menu driven form using dBASE III programming language. It facilitates use of the required dBASE III search and sort capabilities to access records in a database called Generic Communications Index. This index is made up of one record each for all bulletins, circulars, and information notices, including revisions and supplements, from 1971, when such documentation started, through 1986 (or to the latest update). The program is designed for use by anyone modestly acquainted with the general use of IBM-compatible personal computers. The manual contains both a brief overview and a detailed description of the program, as well as detailed instructions for getting started using the program on a personal computer with either a two-floppy disk or a hard disk system. Included at the end are a brief description of how to handle problems which might occur, and notes on the makeup of the program and database files for help in adding records of communications for future years 19. Indexing the etymological lexicographic systems Directory of Open Access Journals (Sweden) Volodymyr Shyrokov 2014-09-01 Full Text Available Indexing the etymological lexicographic systemsThe main problems and directions for the development of the etymological lexicographic systems in the digital environment are studied. The formal conceptual model of the lexicographic system for fundamental academic Etymological Dictionary of the Ukrainian Language (EDUL is developed. The lexicographic structure of the EDUL individual elements are developed and described. The EDUL metalanguage was studied and described. The formal model and technology of the EDUL parsing are worked out. That made it possible to convert automatically the EDUL text into the lexicographic database, which corresponds to the conceptual model of the lexicographic system. The conceptual foundations of instrumental tool to form the etymological dictionaries are developed to create the Virtual Lexicographic Laboratory «Etymological Dictionary of the Ukrainian Language», which was implemented with a modern approach to the real lexicographic array of the EDUL. That allowed to form the database of the EDUL multilingual index (about 250 languages in the automatic mode. This index is a basis of the seventh (final volume of the EDUL. The possibility of applying the developed models to other etymological dictionaries are studied. The conceptual foundations for integration of the etymological lexicographic systems are discussed. 20. Monitoring programme International Nuclear Information System (INIS) Her Majesty's Inspectorate of Pollution's 1992 report on its programme of monitoring radioactive substances is presented. Site operators' returns are verified and the report provides independent data on the environmental impact of authorized disposal of radioactive wastes. Radiation doses which may have been received by members of the public, fall well below the International Commission for Radiological Protection's (ICRP) recommended annual doses. (UK) 1. Manual on environmental monitoring in normal operation International Nuclear Information System (INIS) Many establishments handling radioactive materials produce, and to some extent also discharge, radioactive waste as part of their normal operation. The radiation doses to which members of the public may be exposed during such operation must remain below the stipulated level. The purpose of this manual is to provide technical guidance for setting up programmes of routine environmental monitoring in the vicinity of nuclear establishment. The annex gives five examples of routine environmental monitoring programmes currently in use: these have been indexed separately. 2. A Comparison of the Academic Index on CDROM with Four Wilson Indexes on the OPAC. Science.gov (United States) Miller, Betty 1995-01-01 Reports results of a comparison of the Academic Index on CD-ROM and four indexes on the OPAC (online public access catalog) at Brooklyn College (New York): General Science Index, Humanities Index, Readers' Guide to Periodical Literature, and Social Science Index. Coverage of the "New York Times" was found to be important. (LRW) 3. Phenology-Based Vegetation Index Differencing for Mapping of Rubber Plantations Using Landsat OLI Data Directory of Open Access Journals (Sweden) Hui Fan 2015-05-01 Full Text Available Accurate and up-to-date mapping and monitoring of rubber plantations is challenging. In this study, we presented a simple method for rapidly and accurately mapping rubber plantations in the Xishuangbanna region of southwest China using phenology-based vegetation index differencing. Temporal profiles of the Normalized Difference Vegetation Index (NDVI, Enhanced Vegetation Index (EVI, Atmospherically Resistant Vegetation Index (ARVI, Normalized Difference Moisture Index (NDMI, and Tasselled Cap Greenness (TCG for rubber trees, natural forests and croplands were constructed using 11 Landsat 8 OLI images acquired within one year. These vegetation index time series accurately demonstrated the unique seasonal phenological dynamics of rubber trees. Two distinct phenological phases (i.e., defoliation and foliation of rubber trees were clearly distinguishable from natural forests and croplands. Rubber trees undergo a brief defoliation-foliation process between late December and mid-March. Therefore, vegetation index differencing between the nearly complete defoliation (leaf-off and full foliation (leaf flushing phases was used to delineate rubber plantations within fragmented tropical mountainous landscapes. The method presented herein greatly improved rubber plantation classification accuracy. Overall classification accuracies derived from the differences of the five vegetation indices varied from 92% to 96% with corresponding kappa coefficients of 0.84–0.92. These results demonstrate the promising potential of phenology-based vegetation index differencing for mapping and monitoring rubber expansion at the regional scale. 4. Comparison of Topographic Effects between the Enhanced Vegetation Index (EVI) and Normalized Difference Vegetation Index (NDVI) Science.gov (United States) Matsushita, B.; Yang, W.; Chen, J.; Onda, Y. 2007-12-01 Vegetation indices play an important role in monitoring variations in vegetation. The Enhanced Vegetation Index (EVI) proposed by the MODIS Land Discipline Group and the Normalized Difference Vegetation Index (NDVI) are both global-based vegetation indices aimed at providing consistent spatial and temporal information regarding global vegetation. However, many environmental factors such as atmospheric conditions and soil background may produce errors in these indices. The topographic effect is another very important factor, especially when the indices are used in areas of rough terrain. In this paper, we analyzed differences in the topographic effect between the EVI and the NDVI based on a non-Lambertian model and using two airborne-based images with a spatial resolution of 1.5m acquired from a mountainous area covered by a homogeneous Japanese cypress plantation. The results indicate that the soil adjustment factor "L" in the EVI makes it more sensitive to topographic conditions than is the NDVI. Based on these results, we strongly recommend that the topographic effect be removed from the EVI--as well as from other vegetation indices that similarly include a term without a band ratio format (e.g., the PVI and SAVI)--when these indices are used in conjunction with a high spatial resolution image of an area of rough terrain, where the topographic effect on the vegetarian indices having only a band ratio format (e.g., the NDVI) can usually be ignored. 5. The German Drought Monitor Science.gov (United States) Marx, Andreas; Zink, Matthias; Pommerencke, Julia; Kumar, Rohini; Thober, Stephan; Samaniego, Luis 2015-04-01 Soil moisture droughts reduce the amount of water available to plant growth potentially leading e.g. to crop failure or increased forest fire risk. The threat of human livelihoods in developing countries and large economic losses in developed ones are severe consequences of these events. Monitoring the current state of soil water content allows to improve water management to mitigate the associated damages. Since summer 2014, the German Drought Monitor (GDM, available at: www.ufz.de/droughtmonitor) has been established using an operational hydrological modeling system, which consists of 3 steps: (1) the daily download of meteorological forcing data, consistency check and interpolation of this data, (2) running the mesoscale Hydrologic Model (mHM; Samaniego et al. 2010) and saving the state variables at the end of the model run as restart-file for the next days run, and (3) calculation of the soil moisture index (SMI, Samaniego et al. 2013, JHM) and visualization of the drought data. The hydrological model mHM was used to generate daily soil moisture fields for the period 1954-2013 over the entire area of Germany at a high spatial resolution of 4 x 4 km². The model requires daily precipitation, temperature, and potential evapotranspiration as forcing. A three-layer soil scheme was used to model the soil moisture dynamics over the entire root zone depth. Based on the 60 year simulation of soil moisture, the frequency distributions have been calculated for each grid cell to derive the soil moisture index. In this beta version, we do a monthly online update of the SMI. Furthermore, a trend analysis of drought events for 69 German subregions since 1954 was conducted. It showed that for most parts of Germany, the frequency of abnormally dry conditions increased while the stronger drought situations with SMIindicators shall be provided, and how the information and data shall be presented and distributed. 6. Clinical observation on different doses of dexmedetomidine applied in laparoscopic gynecological surgery under the supervision of bispectral index%脑电双频指数监测下不同剂量右美托咪定在妇科腹腔镜手术的应用 Institute of Scientific and Technical Information of China (English) 黎阳; 张秀丽; 孙丽娜; 周冠华; 周宇峰; 张望 2014-01-01 目的 研究不同剂量右美托咪定在妇科腹腔镜手术中的应用效果.方法 选择妇科腹腔镜手术病人120例,随机分成A、B、C三组,A组为安慰剂组(10 ml生理盐水),B组为小剂量右美托咪定组(0.5μg/kg,右美托咪定),C组为大剂量右美托咪定组(1.0μg/kg右美托咪定).记录输注DEX前(T0)、插管前(T1)、切皮前(T2)、切皮后(T3)、术毕(T4)和拔管后(R)的平均动脉压、心率、芬太尼用量,拨管期躁动、呛咳、术后寒颤、恶心呕吐发生率,分析它们是否有差异.结果 T2、T3、T4和T5时间点相比于T1,三组患者的平均动脉压和心率都有明显升高(P＜0.05),但是此时A组患者的平均动脉压和心率略高于T0时刻的值;B组患者的平均动脉压和心率与T0时刻的值相接近;C组患者的平均动脉压和心率低于T0时刻的值.B、C组芬太尼用量都低于A组,但是B组和C组没有明显差异(P＜0.05).B、C组出现拔管期躁动、呛咳、寒战和恶心呕吐的人数也低于A组,同时C组也低于B组(P＜0.05).结论 腹腔镜妇科手术中使用右美托咪定能维持手术期患者血流动力学稳定,减少麻醉药用量,降低麻醉苏醒期副作用的发生率.%Objective To investigate the efficacy of different doses of dexmedetomidine (DEX) for the laparoscopic gynecological surgery.Methods In the study,120 patients scheduled for elective laparoscopic gynecological surgery in our hospital were randomly divided into three groups:group A (10 ml normal saline),group B (0.5 μ g/kg DEX) and group C (1.0 μ g/kg DEX).Mean artery pressure (MAP),heart rate (HR),the doses of remifentanil and the amount of adverse reactions were recorded before being given dexmedetomidine infusion (T0),immediately before tracheal intubation (T1),before and after skin incision (T2-3),at the end of surgery (T4) and after tracheal intubation(T5),and then analyze if there were any significant differences.Results MAP and HR in three groups at the time T2,T3,T4 and T5 were higher than those at the time T1 (P ＜ 0.05).But the MAP and HR in group A at the time T2,T3,T4 and T5 were also higher than those at the time T0 (P ＜ 0.05).The MAP and HR in group B at the time T2,T3,T4 and T5 were substantially equal to those in the time T0.But MAP and HR in group C at the time T2,T3,T4 and T5 were lower than those at the time T0 (P ＜ 0.05).The doses of remifentanil used in B and C groups were lower than those in group A (P ＜ 0.05),but there was no significant different between the doses of remifentanil used in group B and C (P ＞ 0.05).The incidence of cough,dysphonia,chill and vomit in group B and C were lower than those in group A,and the incidence of cough,dysphonia,chill and vomit in group C were also lower than those in group B (P ＜ 0.05).Conclusion DEX could maintain hemodynamic stability,and reduce the using of hardstuff and the incidence of adverse events in surgical. 7. Experimental comparison between speech transmission index, rapid speech transmission index, and speech intelligibility index. Science.gov (United States) Larm, Petra; Hongisto, Valtteri 2006-02-01 During the acoustical design of, e.g., auditoria or open-plan offices, it is important to know how speech can be perceived in various parts of the room. Different objective methods have been developed to measure and predict speech intelligibility, and these have been extensively used in various spaces. In this study, two such methods were compared, the speech transmission index (STI) and the speech intelligibility index (SII). Also the simplification of the STI, the room acoustics speech transmission index (RASTI), was considered. These quantities are all based on determining an apparent speech-to-noise ratio on selected frequency bands and summing them using a specific weighting. For comparison, some data were needed on the possible differences of these methods resulting from the calculation scheme and also measuring equipment. Their prediction accuracy was also of interest. Measurements were made in a laboratory having adjustable noise level and absorption, and in a real auditorium. It was found that the measurement equipment, especially the selection of the loudspeaker, can greatly affect the accuracy of the results. The prediction accuracy of the RASTI was found acceptable, if the input values for the prediction are accurately known, even though the studied space was not ideally diffuse. PMID:16521772 8. AGILITY INDEXES AND APPLICATION OF PRODUCTION PLANNING Institute of Scientific and Technical Information of China (English) CHEN Zhixiang 2006-01-01 The agility of production planning is defined as two characters: synchronization and flexibility. Measurement indexes for evaluating agility are then divided into two dimensions separately. Synchronization includes two horizontal indexes: order lead time ratio and demand fulfilling rate; Two vertical indexes: instruction-reaction cycle time and resource matching rate.Flexibility includes five indexes: scope flexibility, delivery flexibility, variety flexibility, capacity buffer, inventory buffer and modification flexibility. Quantitative formulas for each measurement index are constructed. One application is discussed to illustrate the feasibility and reasonability of the indexes. 9. Detection of analyte refractive index and concentration using liquid-core photonic Bragg fibers Science.gov (United States) Li, Jingwen; Qu, Hang; Skorobogatiy, Maksim 2016-03-01 We demonstrate detection of liquid analyte refractive index by using a hollow-core photonic Bragg fiber. We apply this fiber sensor to monitor concentrations of commercial cooling oil. The sensor operates on a spectral modality. Variation in the analyte refractive index modifies the bandgap guidance of a fiber, leading to spectral shifts in the fiber transmission spectrum. The sensitivity of the sensor to changes in the analyte refractive index filling in the fiber core is found to be 1460nm/Refractive index unit (RIU). By using the spectral modality and effective medium theory, we determine the concentrations of commercial fluid from the measured refractive indices with an accuracy of ~0.42%. The presented fiber sensor can be used for on-line monitoring of concentration of many industrial fluids and dilutions with sub-1%v accuracy. 10. The use of air quality index (AQI) in environmental management International Nuclear Information System (INIS) The air quality index (AQI) is considered a global air quality index in a particular moment or day and in a specific monitoring station. The AQI is to be interpreted as a guiding air quality index for the general public. Specialists should take into account other factors when studying the pollution levels. The behaviour of air pollution is studied by using the AQI in two monitoring points in Regla, where the main pollutants are measured: SO2, NO2 and total suspended particulates. It was founded that particulates and NO2 are the pollutants that contribute most to the air quality deterioration, which occurs with greater frequency-days in the categories Poor and Bad, and show an increase in the categories Terrible and Critical. The necessary recommendations for the reduction of air pollution are given. The use of this AQI for assessing air pollution in settlements is recommended as a good tool for environmental information and management. A visual scale is proposed to improve and facilitate the public's understanding 11. Modified Palmer Drought Severity Index Based on Distributed Hydrological Simulation Directory of Open Access Journals (Sweden) Denghua Yan 2013-01-01 Full Text Available Drought monitoring at large scale is essential for fighting against drought. Aiming at the limitation of acquiring long-time serial soil moisture and actual evapotranspiration for Palmer drought severity index (PDSI, the paper modified the PDSI based on distributed hydrological model on subbasin level in Luanhe river basin, North China. The water balance was simulated using the Soil and Water Assessment Tool (SWAT. Calibration and validation results showed good agreement between simulated and measured discharges, and the SWAT model can be used to predict hydrological processes in the study area. Then the simulation results of main hydrologic components were used to establish PDSI. The verification of the drought indices showed that the modified PDSI based on SWAT model and Palmer drought severity index could better describe the characteristics of regional drought evolution in the Luanhe river basin. High drought frequency areas were mainly distributed in the grassland regions of upstream located in the eastern part of Inner Mongolia plateau, and the drought area had a significant upward trend form 1973 to 2010. Compared with the traditional Palmer drought severity index, the modified PDSI could reflect the spatial heterogeneity of regional drought and improve the physical mechanism of PDSI. The drought monitoring method can provide technical support for comprehensive understanding of drought and effective preventing and relieving of drought disasters. 12. Personal monitoring International Nuclear Information System (INIS) Sources of ionizing radiation have innumerable applications in the workplace. The potential exposures of the individual workers involved may need to be routinely monitored and records kept of their cumulative radiation doses. There are also occasions when it is necessary to retrospectively determine a dose which may have been received by a worker. This Module explains the basic terminology associated with personal monitoring and describes the principal types of dosimeters and other related techniques and their application in the workplace. The Manual will be of most benefit if it forms part of more comprehensive training or is supplemented by the advice of a qualified expert in radiation protection. Most of the dosimeters and techniques described in this Module can only be provided by qualified experts 13. Energy Monitoring DEFF Research Database (Denmark) Hansen, Claus T.; Madsen, Dines; Christiensen, Thomas; Energy measurement has become an important aspect of our daily lives since we have learned that energy consumption, is one of the main source of global warming. Measuring instruments varies from a simple watt-meter to more sophisticated microprocessor control devices. The negative effects...... that fossil fuels induce on our environment has forced us to research renewable energy such as sunlight, wind etc. This new environmental awareness has also helped us to realize the importance of monitoring and controlling our energy use. The main purpose in this research is to introduce a more sophisticated...... but affordable way to monitor energy consumption of individuals or groups of home appliances. By knowing their consumption the utilization can be regulated for more efficient use. A prototype system has been constructed to demonstrate our idea.... 14. Selective monitoring Science.gov (United States) Homem-de-Mello, Luiz S. 1992-04-01 While in NASA's earlier space missions such as Voyager the number of sensors was in the hundreds, future platforms such as the Space Station Freedom will have tens of thousands sensors. For these planned missions it will be impossible to use the comprehensive monitoring strategy that was used in the past in which human operators monitored all sensors all the time. A selective monitoring strategy must be substituted for the current comprehensive strategy. This selective monitoring strategy uses computer tools to preprocess the incoming data and direct the operators' attention to the most critical parts of the physical system at any given time. There are several techniques that can be used to preprocess the incoming information. This paper presents an approach to using diagnostic reasoning techniques to preprocess the sensor data and detect which parts of the physical system require more attention because components have failed or are most likely to have failed. Given the sensor readings and a model of the physical system, a number of assertions are generated and expressed as Boolean equations. The resulting system of Boolean equations is solved symbolically. Using a priori probabilities of component failure and Bayes' rule, revised probabilities of failure can be computed. These will indicate what components have failed or are the most likely to have failed. This approach is suitable for systems that are well understood and for which the correctness of the assertions can be guaranteed. Also, the system must be such that assertions can be made from instantaneous measurements. And the system must be such that changes are slow enough to allow the computation. 15. Material monitoring International Nuclear Information System (INIS) Waste Reduction Operations Complex (WROC) facilities are located at the Idaho National Engineering Laboratory (INEL). The overall goal for the Pollution Prevention/Waste Minimization Unit is to identify and establish the correct amount of waste generated so that it can be reduced. Quarterly, the INEL Pollution Prevention (P2) Unit compares the projected amount of waste generated per process with the actual amount generated. Examples of waste streams that would be addresses for our facility would include be are not limited to: Maintenance, Upgrades, Office and Scrap Metal. There are three potential sources of this variance: inaccurate identification of those who generate the waste; inaccurate identification of the process that generates the waste; and inaccurate measurement of the actual amount generated. The Materials Monitoring Program was proposed to identify the sources of variance and reduce the variance to an acceptable level. Prior to the implementation of the Material Monitoring Program, all information that was gathered and recorded was done so through an informal estimation of waste generated by various personnel concerned with each processes. Due to the inaccuracy of the prior information gathering system, the Material Monitoring Program was established. The heart of this program consists of two main parts. In the first part potential waste generators provide information on projected waste generation process. In the second part, Maintenance, Office, Scrap Metal and Facility Upgrade wastes from given processes is disposed within the appropriate bin dedicated to that process. The Material Monitoring Program allows for the more accurate gathering of information on the various waste types that are being generated quarterly 16. Ecotoxicology monitoring International Nuclear Information System (INIS) Quick, robust techniques are needed to monitor factory effluent in sewers and rivers. This book compares and contrasts the techniques available from the simple, rapid Microtox test, to tests based on fish, algae or sophisticated chemical analysis. It also discusses the biochemistry and mechanisms of the biological processes involved. Moreover the book surveys the current regulatory and legislative positions in Europe and the United States. (orig./MG) 17. Regional indexes for France. Methodology International Nuclear Information System (INIS) According to the U.S. Department of Energy, an estimated 25% of the GNP is affected by weather-related events. The variations in temperature - even small ones - can also have long-lasting effects on the operational results of a company. Among other, the Energy supply sector is sensitive to weather risks: a milder or harsher than usual winter leads to a decrease or increase of energy consumption. The price of electricity on power trading facilities like Powernext is especially sensitive to odd changes in temperatures. Powernext and Meteo-France (the French meteorological agency) have joined expertise in order to promote the use of weather indices in term of decision making or underlying of hedging tools to energy actors, end users from any other sector of activity and specialists of the weather risk hedging. The Powernext Weather indices are made from information collected by Meteo-France's main observation network according to the norms of international meteorology, in areas carefully selected. The gross data are submitted to a thorough review allowing the correction of abnormalities and the reconstitution of missing data. Each index is fashioned to take into account the economic activity in the various regions of the country as represented by each region's population. This demographic information represents a fair approximation of the weight of the regional economic activity. This document presents the calculation methodology of regional weather indexes for France. Each regional index covers an homogenous area in terms of temperature represented by the biggest city. Five reference cities are used to represent the 22 economical regions of France (Paris Orly, Lyon, Marignane, Bordeaux and Strasbourg). (J.S.) 18. Rejection index for pressure tubes International Nuclear Information System (INIS) The objective of the present study was to establish a set of criteria (or Rejection Index) which could be used to decide whether a zirconium-2 1/2 w/o niobium pressure tube in a CANDU reactor should be removed from service due to in-service degradation. A critique of key issues associated with establishing a realistic rejection index was prepared. Areas of uncertainty in available information were identified and recommendations for further analysis and laboratory testing made. A Rejection Index based on the following limits has been recommended: 1) Limits related to design intent and normal operation: any garter spring must remain within the tolerance band specified for its design location; the annulus gas system must normally be operated in a circulating mode with a procedure in place for purging to prevent accumulation of deuterium. It must remain sensitive to leaks into any part of the systems; and pressure tube dimensions and distortions must be limited to maintain the fuel channels within the original design intent; 2) Limits related to defect tolerance: adequate time margins between occurrence of a leaking crack and unstable failure must be demonstrated for all fuel channels; long lap-type flaws are unacceptable; crack-like defects of any size are unacceptable; and score marks, frat marks and other defects with contoured profiles must fall below certain depth, length and stress intensity limits; and 3) Limits related to property degradation: at operating temperature each pressure tube must be demonstrated to have a critical length in excess of a stipulated value; the maximum equivalent hydrogen level in any pressure tube should not exceed a limit which should be defined taking into account the known history of that tube; the maximum equivalent hydrogen level in any rolled joint should not exceed a limit which is presently recommended as 200 ppm equivalent hydrogen; and the maximum diametral creep strain should be limited to less than 5% 19. Individual monitoring International Nuclear Information System (INIS) This Practical Radiation Technical Manual is one of a series which has been designed to provide guidance on radiological protection for employers, Radiation Protection Officers, managers and other technically competent persons who have a responsibility to ensure the safety of employees working with ionizing radiation. The Manual may be used together with the appropriate IAEA Practical Radiation Safety Manual to provide adequate training, instruction or information on individual monitoring for all employees engaged in work with ionizing radiations. Sources of ionizing radiation have a large number of applications in the workplace. The exposures of the individual workers involved may need to be routinely monitored and records kept of their cumulative radiation doses. There are also occasions when it is necessary to retrospectively determine a dose which may have been received by a worker. This Manual explains the basic terminology associated with individual monitoring and describes the principal types of dosimeters and other related techniques and their application in the workplace. The Manual will be of most benefit if it forms part of more comprehensive training or is supplemented by the advice of a qualified expert in radiation protection. Most of the dosimeters and techniques described in this Manual can only be provided by qualified experts 20. Monitoring oxygenation. Science.gov (United States) Severinghaus, John W 2011-06-01 Cyanosis was used for a century after dentists began pulling teeth under 100% N(2)O in 1844 because brief (2 min) severe hypoxia is harmless. Deaths came with curare and potent anesthetic respiratory arrest. Leland Clark's invention of a polarographic blood oxygen tension electrode (1954) was introduced for transcutaneous PO2 monitoring to adjust PEEP and CPAP PO2 to prevent premature infant blindness from excess O2 (1972). Oximetry for warning military aviators was tried after WW II but not used for routine monitoring until Takuo Aoyagi (1973) discovered an equation to measure SaO2 by the ratio of ratios of red and IR light transmitted through tissue as it changed with arterial pulses. Pulse oximetry (1982) depended on simultaneous technology improvements of light emitting red and IR diodes, tiny cheap solid state sensors and micro-chip computers. Continuous monitoring of airway anesthetic concentration and oxygen also became very common after 1980. Death from anesthesia fell 10 fold between 1985 and 2000 as pulse oximetry became universally used, but no proof of a causative relationship to pulse oximetry exists. It is now assumed that all anesthesiologist became much more aware of the dangers of prolonged hypoxia, perhaps by using the pulse oximeters. PMID:21717228 1. New approaches for index insurance OpenAIRE Skees, Jerry R.; Collier, Benjamin 2010-01-01 The El Niño Southern Oscillation (ENSO) is a climate event associated with warming sea surface temperatures in the Pacific Ocean. In years of extreme El Niño events, areas in northern Peru experience catastrophic flooding. As of 2010, it is possible for stakeholders in northern Peru to purchase a new form of insurance that pays out just as flooding begins and stakeholders begin incurring extra costs and consequential losses. Given the high basis risk associated with selling index insurance to... 2. An index for sustainable development Directory of Open Access Journals (Sweden) Enrico Casadio Tarabusi 2004-06-01 Full Text Available As a possible improvement to the United Nations' Human Development Index (HDI, we propose including in the set of individual variables some of an environmental or social nature. Thus, by rescaling all the variables non-linearly it is possible to mitigate the effect of outliers and synthesize by principal components, or alternatively by a different averaging method that takes sustainability into account and penalizes unbalances among different aspects of development. Both methods are easy to implement and calibrate. The ensuing effect on the ranking of world countries is compared to the HDI ranking. 3. Video OCR for Video Indexing CERN Document Server S., Sankirti 2011-01-01 Video OCR is a technique that can greatly help to locate the topics of interest in video via the automatic extraction and reading of captions and annotations. Text in video can provide key indexing information. Recognizing such text for search application is critical. Major difficult problem for character recognition for videos is degraded and deformated characters, low resolution characters or very complex background. To tackle the problem preprocessing on text image plays vital role. Most of the OCR engines are working on the binary image so to find a better binarization procedure for image to get a desired result is important.Accurate binarization process minimizes the error rate of video OCR. 4. Generation of ride comfort index OpenAIRE Garcia Solano, Javier 2014-01-01 The main objective of this project is to obtain a ride comfort index of a vehicle. This parameter shall be representative of the vibration received by the human body during the ride. The comfort, as we understand, is the sensation which comes from vehicle dynamics and not from the luxury cabin. Initially the comfort evaluation of the cars was done subjectively. The driver-tester exposed his own feelings when he tested the car on a random circuit and compared with other vehicles that he tes... 5. Evaluation of a reproductive index for estimating productivity of grassland breeding birds Science.gov (United States) Morgan, M.R.; Norment, C.; Runge, M.C. 2010-01-01 Declining populations of grassland breeding birds have led to increased efforts to assess habitat quality, typically by estimating density or relative abundance. Because some grassland habitats may function as ecological traps, a more appropriate metric for determining quality is breeding success, which is challenging to determine for many cryptic-nesting grassland birds. This difficulty led Vickery et al. (1992) to propose a reproductive index based on behavioral observations rather than nest fate. We rigorously evaluated the index for 2 years using a Savannah Sparrow (Passerculus sandwichensis) population in western New York and found a weak correlation in classification of the breeding stages of monitored territories among multiple observers (r = 0.398). We also discovered a large difference between overall territory and nest success rates independently estimated with the index (9.8% over the entire breeding cycle) and with nest searching and monitoring (41.7% of nests successfully fledged young). Most importantly, we made territory-level comparisons of index estimates with actual nest fate and found that the index correctly predicted fates for only 43% of the monitored nests. A Mayfield logistic regression analysis demonstrated that only index rank 4 (eggs hatched, but young failed to fledge) showed a strong positive correlation with nest success. Although the reproductive index may function as a coarse indicator of habitat suitability (e.g., documenting production in potential ecological traps), in our study the index exhibited neither internal consistency nor the ability to predict nest fate at the plot or territory level and functioned poorly as a substitute for nest searching and monitoring. ?? 2010 The American Ornithologists' Union. 6. Analysis of Index Gases of Coal Spontaneous Combustion Using Fourier Transform Infrared Spectrometer OpenAIRE Xiaojun Tang; Yuntao Liang; Haozhe Dong; Yong Sun; Haizhu Luo 2014-01-01 Analysis of the index gases of coal for the prevention of spontaneous combustion is of great importance for the enhancement of coal mine safety. In this work, Fourier Transform Infrared Spectrometer (FTIRS) is presented to be used to analyze the index gases of coal in real time to monitor spontaneous combustion conditions. Both the instrument parameters and the analysis method are introduced at first by combining characteristics of the absorption spectra of the target analyte with the analysi... 7. STUDY OF POND WATER QUALITY BY THE ASSESSMENT OF PHYSICOCHEMICAL PARAMETERS AND WATER QUALITY INDEX OpenAIRE Vinod Jena; Satish Dixit; Ravi ShrivastavaSapana Gupta; Sapana Gupta 2013-01-01 Water quality index (WQI) is a dimensionless number that combines multiple water quality factors into a single number by normalizing values to subjective rating curves. Conventionally it has been used for evaluating the quality of water for water resources suchas rivers, streams and lakes, etc. The present work is aimed at assessing the Water Quality Index (W.Q.I) ofpond water and the impact of human activities on it. Physicochemical parameters were monitored for the calculation of W.Q.I for ... 8. Indexes to Nuclear Regulatory Commission issuances, January--June 1995. Volume 41, Index 2 Energy Technology Data Exchange (ETDEWEB) NONE 1995-09-01 Digests and indexes for issuances of the Commission (CLI), the Atomic Safety and Licensing Board Panel (LBP), the Administrative Law Judges (ALJ), the directors Decisions (DD), and the Denials of Petitions for rulemaking (DPRM) are presented in this document. These digests and indexes are intended to serve as a guide to the issuances. The information elements are displayed in one or more of five separate formats arranged as follows: Case name index; digests and headers; legal citations index; subject index; and facility index. 9. Indexes to Nuclear Regulatory Commission issuances, January-March 1984. Volume 19, Index 1 International Nuclear Information System (INIS) Digests and indexes for issuances of the Commission, the Atomic Safety and Licensing Appeal Panel, the Atomic Safety and Licensing Board Panel, the Administrative Law Judge, the Directors' Decisions, and the Denials of Petitions of Rulemaking are presented in this document. These digests and indexes are intended to serve as a guide to the issuances. Information elements are displayed in one or more of five separate formats: Case Name Index, Digests and Headers, Legal Citations Index, Subject Index, and Facility Index 10. Indexes to Nuclear Regulatory Commission issuances, January--June 1995. Volume 41, Index 2 International Nuclear Information System (INIS) Digests and indexes for issuances of the Commission (CLI), the Atomic Safety and Licensing Board Panel (LBP), the Administrative Law Judges (ALJ), the directors' Decisions (DD), and the Denials of Petitions for rulemaking (DPRM) are presented in this document. These digests and indexes are intended to serve as a guide to the issuances. The information elements are displayed in one or more of five separate formats arranged as follows: Case name index; digests and headers; legal citations index; subject index; and facility index 11. The local index formula in noncommutative geometry International Nuclear Information System (INIS) These notes present a partial account of the local index theorem in non-commutative geometry discovered by Alain Connes and Henri Moscovici. It includes Elliptic partial differential operators, cyclic homology theory, Chern characters, homotopy invariants and the index formulas 12. The inconsistency of the h-index CERN Document Server Waltman, Ludo 2011-01-01 The h-index is a popular bibliometric indicator for assessing individual scientists. We criticize the h-index from a theoretical point of view. We argue that for the purpose of measuring the overall scientific impact of a scientist (or some other unit of analysis) the h-index behaves in a counterintuitive way. In certain cases, the mechanism used by the h-index to aggregate publication and citation statistics into a single number leads to inconsistencies in the way in which scientists are ranked. Our conclusion is that the h-index cannot be considered an appropriate indicator of a scientist's overall scientific impact. Based on recent theoretical insights, we discuss what kind of indicators can be used as an alternative to the h-index. We pay special attention to the highly cited publications indicator. This indicator has a lot in common with the h-index, but unlike the h-index it does not produce inconsistent rankings. 13. KWIC Index of nuclear codes (1975 edition) International Nuclear Information System (INIS) It is a KWIC Index for 254 nuclear codes in the Nuclear Code Abstracts (1975 edition). The classification of nuclear codes and the form of index are the same as those in the Computer Programme Library at Ispra, Italy. (auth.) 14. Scaling in the Bombay stock exchange index Indian Academy of Sciences (India) Ashok Razdan 2002-03-01 In this paper we study Bombay stock exchange (BSE) index financial time series for fractal and multifractal behaviour. We show that BSE index time series is monofractal and can be represented by a fractional Brownian motion. 15. Automatic inference of indexing rules for MEDLINE Directory of Open Access Journals (Sweden) Shooshan Sonya E 2008-11-01 Full Text Available Abstract Background: Indexing is a crucial step in any information retrieval system. In MEDLINE, a widely used database of the biomedical literature, the indexing process involves the selection of Medical Subject Headings in order to describe the subject matter of articles. The need for automatic tools to assist MEDLINE indexers in this task is growing with the increasing number of publications being added to MEDLINE. Methods: In this paper, we describe the use and the customization of Inductive Logic Programming (ILP to infer indexing rules that may be used to produce automatic indexing recommendations for MEDLINE indexers. Results: Our results show that this original ILP-based approach outperforms manual rules when they exist. In addition, the use of ILP rules also improves the overall performance of the Medical Text Indexer (MTI, a system producing automatic indexing recommendations for MEDLINE. Conclusion: We expect the sets of ILP rules obtained in this experiment to be integrated into MTI. 16. Enhanced index tracking modelling in portfolio optimization Science.gov (United States) Lam, W. S.; Hj. Jaaman, Saiful Hafizah; Ismail, Hamizun bin 2013-09-01 Enhanced index tracking is a popular form of passive fund management in stock market. It is a dual-objective optimization problem, a trade-off between maximizing the mean return and minimizing the risk. Enhanced index tracking aims to generate excess return over the return achieved by the index without purchasing all of the stocks that make up the index by establishing an optimal portfolio. The objective of this study is to determine the optimal portfolio composition and performance by using weighted model in enhanced index tracking. Weighted model focuses on the trade-off between the excess return and the risk. The results of this study show that the optimal portfolio for the weighted model is able to outperform the Malaysia market index which is Kuala Lumpur Composite Index because of higher mean return and lower risk without purchasing all the stocks in the market index. 17. Climate index for France - Methodology International Nuclear Information System (INIS) According to the U.S. Department of Energy, an estimated 25% of the GNP is affected by weather-related events. The variations in temperature - even small ones - can also have long-lasting effects on the operational results of a company. Among other, the Energy supply sector is sensitive to weather risks: a milder or harsher than usual winter leads to a decrease or increase of energy consumption. The price of electricity on power trading facilities like Powernext is especially sensitive to odd changes in temperatures. Powernext and Meteo-France (the French meteorological agency) have joined expertise in order to promote the use of weather indices in term of decision making or underlying of hedging tools to energy actors, end users from any other sector of activity and specialists of the weather risk hedging. The Powernext Weather indices are made from information collected by Meteo-France's main observation network according to the norms of international meteorology, in areas carefully selected. The gross data are submitted to a thorough review allowing the correction of abnormalities and the reconstitution of missing data. Each index is fashioned to take into account the economic activity in the various regions of the country as represented by each region's population. This demographic information represents a fair approximation of the weight of the regional economic activity. This document presents the calculation methodology of average, minimum and maximum weather indexes with the winter and summer regression equations for the different economical regions of France. (J.S.) 18. Environmental/Biomedical Terminology Index Energy Technology Data Exchange (ETDEWEB) Huffstetler, J.K.; Dailey, N.S.; Rickert, L.W.; Chilton, B.D. 1976-12-01 The Information Center Complex (ICC), a centrally administered group of information centers, provides information support to environmental and biomedical research groups and others within and outside Oak Ridge National Laboratory. In-house data base building and development of specialized document collections are important elements of the ongoing activities of these centers. ICC groups must be concerned with language which will adequately classify and insure retrievability of document records. Language control problems are compounded when the complexity of modern scientific problem solving demands an interdisciplinary approach. Although there are several word lists, indexes, and thesauri specific to various scientific disciplines usually grouped as Environmental Sciences, no single generally recognized authority can be used as a guide to the terminology of all environmental science. If biomedical terminology for the description of research on environmental effects is also needed, the problem becomes even more complex. The building of a word list which can be used as a general guide to the environmental/biomedical sciences has been a continuing activity of the Information Center Complex. This activity resulted in the publication of the Environmental Biomedical Terminology Index (EBTI). 19. Viscosity Index Improvers and Thickeners Science.gov (United States) Stambaugh, R. L.; Kinker, B. G. The viscosity index of an oil or an oil formulation is an important physical parameter. Viscosity index improvers, VIIs, are comprised of five main classes of polymers: polymethylmethacrylates (PMAs), olefin copolymers (OCPs), hydrogenated poly(styrene-co-butadiene or isoprene) (HSD/SIP/HRIs), esterified polystyrene-co-maleic anhydride (SPEs) and a combination of PMA/OCP systems. The chemistry, manufacture, dispersancy and utility of each class are described. The comparative functions, properties, thickening ability, dispersancy and degradation of VIIs are discussed. Permanent and temporary shear thinning of VII-thickened formulations are described and compared. The end-use performance and choice of VI improvers is discussed in terms of low- and high-temperature viscosities, journal bearing oil film thickness, fuel economy, oil consumption, high-temperature pumping efficiency and deposit control. Discussion of future developments concludes that VI improvers will evolve to meet new challenges of increased thermal-oxidative degradation from increased engine operating temperatures, different base stocks of either synthetic base oils or vegetable oil-based, together with alcohol- or vegetable oil-based fuels. VI improvers must also evolve to deal with higher levels of fuel dilution and new types of sludge and also enhanced low-temperature requirements. 20. Climate index for Spain - Methodology International Nuclear Information System (INIS) According to the U.S. Department of Energy, an estimated 25% of the GNP is affected by weather-related events. The variations in temperature - even small ones - can also have long-lasting effects on the operational results of a company. Among other, the Energy supply sector is sensitive to weather risks: a milder or harsher than usual winter leads to a decrease or increase of energy consumption. The price of electricity on power trading facilities like Powernext is especially sensitive to odd changes in temperatures. Powernext and Meteo-France (the French meteorological agency) have joined expertise in order to promote the use of weather indices in term of decision making or underlying of hedging tools to energy actors, end users from any other sector of activity and specialists of the weather risk hedging. The Powernext Weather indices are made from information collected by Meteo-France's main observation network according to the norms of international meteorology, in areas carefully selected. The gross data are submitted to a thorough review allowing the correction of abnormalities and the reconstitution of missing data. Each index is fashioned to take into account the economic activity in the various regions of the country as represented by each region's population. This demographic information represents a fair approximation of the weight of the regional economic activity. This document presents the calculation methodology of average, minimum and maximum weather indexes with the winter and summer regression equations for the different economical regions of Spain. (J.S.) 1. Climate index for Belgium - Methodology International Nuclear Information System (INIS) According to the U.S. Department of Energy, an estimated 25% of the GNP is affected by weather-related events. The variations in temperature - even small ones - can also have long-lasting effects on the operational results of a company. Among other, the Energy supply sector is sensitive to weather risks: a milder or harsher than usual winter leads to a decrease or increase of energy consumption. The price of electricity on power trading facilities like Powernext is especially sensitive to odd changes in temperatures. Powernext and Meteo-France (the French meteorological agency) have joined expertise in order to promote the use of weather indices in term of decision making or underlying of hedging tools to energy actors, end users from any other sector of activity and specialists of the weather risk hedging. The Powernext Weather indices are made from information collected by Meteo-France's main observation network according to the norms of international meteorology, in areas carefully selected. The gross data are submitted to a thorough review allowing the correction of abnormalities and the reconstitution of missing data. Each index is fashioned to take into account the economic activity in the various regions of the country as represented by each region's population. This demographic information represents a fair approximation of the weight of the regional economic activity. This document presents the calculation methodology of average, minimum and maximum weather indexes with the winter and summer regression equations for the different economical regions of Belgium. (J.S.) 2. Climate index for Switzerland - Methodology International Nuclear Information System (INIS) According to the U.S. Department of Energy, an estimated 25% of the GNP is affected by weather-related events. The variations in temperature - even small ones - can also have long-lasting effects on the operational results of a company. Among other, the Energy supply sector is sensitive to weather risks: a milder or harsher than usual winter leads to a decrease or increase of energy consumption. The price of electricity on power trading facilities like Powernext is especially sensitive to odd changes in temperatures. Powernext and Meteo-France (the French meteorological agency) have joined expertise in order to promote the use of weather indices in term of decision making or underlying of hedging tools to energy actors, end users from any other sector of activity and specialists of the weather risk hedging. The Powernext Weather indices are made from information collected by Meteo-France's main observation network according to the norms of international meteorology, in areas carefully selected. The gross data are submitted to a thorough review allowing the correction of abnormalities and the reconstitution of missing data. Each index is fashioned to take into account the economic activity in the various regions of the country as represented by each region's population. This demographic information represents a fair approximation of the weight of the regional economic activity. This document presents the calculation methodology of average, minimum and maximum weather indexes with the winter and summer regression equations for the different economical regions of Switzerland. (J.S.) 3. Climate index for Italy - Methodology International Nuclear Information System (INIS) According to the U.S. Department of Energy, an estimated 25% of the GNP is affected by weather-related events. The variations in temperature - even small ones - can also have long-lasting effects on the operational results of a company. Among other, the Energy supply sector is sensitive to weather risks: a milder or harsher than usual winter leads to a decrease or increase of energy consumption. The price of electricity on power trading facilities like Powernext is especially sensitive to odd changes in temperatures. Powernext and Meteo-France (the French meteorological agency) have joined expertise in order to promote the use of weather indices in term of decision making or underlying of hedging tools to energy actors, end users from any other sector of activity and specialists of the weather risk hedging. The Powernext Weather indices are made from information collected by Meteo-France's main observation network according to the norms of international meteorology, in areas carefully selected. The gross data are submitted to a thorough review allowing the correction of abnormalities and the reconstitution of missing data. Each index is fashioned to take into account the economic activity in the various regions of the country as represented by each region's population. This demographic information represents a fair approximation of the weight of the regional economic activity. This document presents the calculation methodology of average, minimum and maximum weather indexes with the winter and summer regression equations for the different economical regions of Italy. (J.S.) 4. Environmental/Biomedical Terminology Index International Nuclear Information System (INIS) The Information Center Complex (ICC), a centrally administered group of information centers, provides information support to environmental and biomedical research groups and others within and outside Oak Ridge National Laboratory. In-house data base building and development of specialized document collections are important elements of the ongoing activities of these centers. ICC groups must be concerned with language which will adequately classify and insure retrievability of document records. Language control problems are compounded when the complexity of modern scientific problem solving demands an interdisciplinary approach. Although there are several word lists, indexes, and thesauri specific to various scientific disciplines usually grouped as Environmental Sciences, no single generally recognized authority can be used as a guide to the terminology of all environmental science. If biomedical terminology for the description of research on environmental effects is also needed, the problem becomes even more complex. The building of a word list which can be used as a general guide to the environmental/biomedical sciences has been a continuing activity of the Information Center Complex. This activity resulted in the publication of the Environmental Biomedical Terminology Index 5. Dow's chemical exposure index guide International Nuclear Information System (INIS) A number of events in the 1970's and 1980's impacted the course of process safety. Incidents such as Flixborough, Seveso, Three-Mile Island, and Bhopal are well known throughout industry and are recognized as examples of major disasters. Even though events leading up to these disasters were completely different they had one common element between them: a substance was released from a manufacturing unit, became airborne and presented a hazard of such magnitude as to place the safety of both employees and the surrounding public in jeopardy. As a result, industry became increasingly concerned regarding potential loss, in human and economic terms, as plants and equipment grew in size. The Flixborough incident raised the level of concern for process safety, particularly in terms of the hazards presented by fire and explosion. Seveso and Three-Mile Island emphasized the need to consider far-field exposure. The Bhopal incident created an urgent need to recognize and understand the expected downwind impact of potential releases of acutely toxic substances to the air. In order to meet this need, the Dow Chemical Company, a recognized leader in the area of safety and loss prevention, presented a Chemical Exposure Index in 1986. AIChE has recently published an updated version entitled Dow's Chemical Exposure Index Guide. 7 refs., 5 figs 6. Protein Solubility as Quality Index for Processed Soybean Directory of Open Access Journals (Sweden) Rodica Căpriţă 2010-05-01 Full Text Available Protein quality of soybean meal (SBM is linked to both the reduction of antinutritional factors (ANFs, and the optimization of protein digestibility. Both insufficient- and over-heating result in poor quality SBM. Inadequate heating fails to completely destroy the ANFs, which may have a detrimental impact on animal performance, while excessive heating reduces the availability of lysine via the Maillard reaction and possibly, to a lesser extent, of other amino acids. The objective of our study was to compare some biochemical laboratory procedures for assessing quality of SBM: urease index (UI, protein dispersibility index (PDI, KOH protein solubility (PS, and nitrogen solubility index (NSI. The experimental data reveal that UI is not useful to determine excessive heat treatment since additional heating has no effect on the urease index. KOH protein solubility remains high, during initial heat treatment. In marked contrast, the PDI and NSI decreased incrementally from 78% to 20% and from 97% to 60%, respectively, when heating 0 to 30 minutes. Combing the PDI test with the urease test could be useful to monitor soybean quality. SBM containing low UI (0.3 or below and high PDI (40 to 45% may indicate that the sample is definitely high quality because it has been adequately heat processed, but not overprocessed. 7. Photonuclear data index 1986-1990 International Nuclear Information System (INIS) This issue presents a bibliographic index to experimental photonuclear data published in periodical scientific literature during the years 1986-1990. The main tabulation is sorted by nucleus and reaction. It is supplemented by a reference index, an author index, explanatory tables of terms and abbreviations used, and a table of isotopic abundances and nucleon separation energies. The index is in English with an introduction in Russian and English. (author) 8. Index of Selected Textile Journals of 2002 OpenAIRE Rafiq, Muhammad 2003-01-01 It is the complete index of the six renowned journals of textiles. The index is arranged by keywords and entries are well formated. The index covers the published issues of year 2002 of the following journals. Library World, Coloration Technology, AATCC Review, Pakistan Textile Journal, Textile Research Journal, International Dyer, and Textile Today. The index is useful for textile designers, textile engineers, fashion designers, managers, decision makers, and researchers. 9. A Scenario of Rainfall Erosivity Index Research OpenAIRE D .V. Pandit1; R. K. Isaac2 2015-01-01 Rainfall erosivity index is an important index to evaluate the soil loss due to rainfall. Rainstorm plays a paramount role in surface sealing, runoff and erosion process. Research on rainfall erosivity index is important in understanding the mechanism of soil erosion processes. This paper gives a scenario on the important research work done by the scientists to evaluate the erosivity index by using various methods and approaches. The aim of this paper was also to highl... 10. Author Index, From > 1988-1992 International Nuclear Information System (INIS) In 1988-1992, 824 papers were published in >. The papers were contributed by 1497 authors. The author index of the papers is annexed. The author index is divided into contained two parts: the first part is chinese author index, and the second part is foreign author index. The former is arranged according to the chinese phonetic alphabet. The latter is arranged according to the English alphabet 11. Body Mass Index (BMI) Charts (For Parents) Science.gov (United States) ... 5 Things to Know About Zika & Pregnancy Body Mass Index (BMI) Charts KidsHealth > For Parents > Body Mass Index (BMI) Charts Print A A A Text ... same age. Now they have another tool: body mass index (BMI). BMI is a calculation that uses ... 12. One-Eyed King: Automated Indexing. Science.gov (United States) Oliver, Christine Tomaszuk 1989-01-01 Describes the mechanistic model of language on which automatic indexing is based, and examines the underlying assumptions of the model to demonstrate the ineffectiveness of this indexing. It is argued that theoretical research from the fields of linguistics, psychology, and philosophy need to be incorporated into automatic indexing to overcome… 13. Finding and Indexing of Eccentric Events in Video Emanates Directory of Open Access Journals (Sweden) Md. Haidar Sharif 2010-02-01 Full Text Available We propose a methodology that first extracts features of video emanates and detects eccentric events in a crowded environment. Afterwards eccentric events are indexed for retrieval. The motivation of the framework is the discrimination of features which are independent from the application domains. Low-level as well as midlevel features are generic and independent of the type of abnormality. High-level features are dependent and used to detect eccentric events, whereas both mid-level and highlevel features are run through the indexing scheme for retrieval. To demonstrate the interest of the methodology, we primarily present the obtained results on collapsing events in real videos amassed by single camera installed an airport escalator exits to monitor the circumstances of those regions. 14. Perfusion index variations in clinically and hemodynamically stable preterm newborns in the first week of life Directory of Open Access Journals (Sweden) Farinasso Daniela 2010-01-01 Full Text Available Abstract Background The perfusion index, derived from the pulse oximeter signal, seems to be an accurate predictor for high illness severity in newborns. The aim of this study was to determine the perfusion index values of clinically and hemodynamically stable preterm newborns in the first week of life. Methods Perfusion index recordings were performed on the first, third and seventh day of life on 30 preterm newborns. Their state of health was assessed according to clinical and behaviour evaluation and to the Score for Neonatal Acute Physiology. Results The median(interquartile range perfusion index values were 0.9(0.6 on the first, 1.2(1.0 on the third, and 1.3(0.9 on the seventh day, with a significant increase between the first and the third day. Conclusions Perfusion index proved to be an easily applicable, non-invasive method for monitoring early postnatal changes in peripheral perfusion. Its trend during the first week of life suggests that its clinical application should take age into account. Further studies are needed to obtain reference perfusion index values from a larger sample of preterm newborns, to identify specific gestational age-related cut-off values for illness and to test the role of perfusion index in monitoring critically ill neonates. 15. Photoplethysmogram reflection index and aging Science.gov (United States) Qawqzeh, Yousef K.; Reaz, M. B. I.; Maskon, O.; Chellappan, Kalaivani; Ali, M. A. M. 2011-10-01 This study conducted to investigate and study the effect of aging on Photoplethysmogram (PPG) signal and the effects of aging on the calculations of reflection index (RI). The results showed that PPG is highly affected by aging which noteworthy to be observed by the variations of PPG contour. Since we advance in age, PPG becomes more rounded which in turn make PPG inflection point and dicrotic notch less pronounced. As a conclusion, RI may provide a window to small and medium arteries compliance and it can be a measure of small and medium arteries stiffness. When small and medium arteries start stiffening, early detection of atherosclerosis in sub-clinical settings can be investigated and detected. 16. COMPUTED TOMOGRAPHY PERITONEAL CANCER INDEX Directory of Open Access Journals (Sweden) Tiutiuca RC 2006-07-01 Full Text Available Peritoneal surface malignancy results from seeding of gastrointestinal cancer or abdomino-pelvic sarcoma, or it can occur as a primary disease, such as peritoneal mesothelioma. In the past, this clinical situation was treated only with palliative intent. Actual treatment options for surgical management uses cytoreductive surgery which combines peritonectomy and visceral resection in an effort to remove all visible cancer within the abdomen and pelvis. Then the peritoneal cavity is flooded with chemotherapy solution. To select patients for this agressive approach quantitative prognostic indicators for carcinomatosis must be evaluated. The peritoneal cancer index (PCI is a synthesis of the distribution of tumor and a lesion size score. In such conditions abdominal medium contrast computed-tomography it is very helpful in identification of neoplasic implants. 17. Gallagher index for sociophysical models Science.gov (United States) Gwizdalla, Tomasz M. 2008-05-01 The use of physical formalism and methods as a tool for the analysis of sociological problems became popular since the papers of Galam or Stauffer, followed by the authors of some interesting models, based often on the study of cellular automata evolution. In this paper we are going to deduce some characteristics concerning the results of elections on the basis of the multi-opinion Sznajd model. The values of interest are: Gallagher index, measuring the disproportionality of elections; the efficiency of election process measured with the possibility of government creation and government stability. The results show that it is possible to obtain some well known effects even using quite a simple model of social behaviour and that different methods of votes counting respond to different needs formulated as the aim of elections. 18. Stock market index prediction using neural networks Science.gov (United States) Komo, Darmadi; Chang, Chein-I.; Ko, Hanseok 1994-03-01 A neural network approach to stock market index prediction is presented. Actual data of the Wall Street Journal's Dow Jones Industrial Index has been used for a benchmark in our experiments where Radial Basis Function based neural networks have been designed to model these indices over the period from January 1988 to Dec 1992. A notable success has been achieved with the proposed model producing over 90% prediction accuracies observed based on monthly Dow Jones Industrial Index predictions. The model has also captured both moderate and heavy index fluctuations. The experiments conducted in this study demonstrated that the Radial Basis Function neural network represents an excellent candidate to predict stock market index. 19. XINIX: Extended Inverted Index for Keyword Search Directory of Open Access Journals (Sweden) Jomon Joseph 2014-09-01 Full Text Available Keyword search is the easiest way to access the data in the face of information explosion. Inverted lists are used to index documents to access those documents according to a set of keywords efficiently. These inverted lists are large in size. So, many compression techniques have been proposed to reduce the storage space and disk I/O time. This paper presents a convenient index structure, which is an extension of the Generalized Inverted Index (GINIX. Ginix merges the consecutive IDs in inverted lists into interval lists and it reduces the size of the inverted index. The new index structure is called Extended Inverted Index (XINIX which extends the structure of Ginix. The primary objective of Xinix is to minimize the storage cost. Xinix not only reduces the storage cost, but also increase the search performance, compared with traditional inverted indexes. 20. Biomathematical Approach Towards a Linear Climatic Index Directory of Open Access Journals (Sweden) V. Kumar 1985-01-01 Full Text Available The approach is aimed towards integration of major climatic elements for evolving a linear climatic index based on annual averages of three climatic parameters, viz; diurnal range of temperatures, daily mean temperature and precipitation respectively. The index is a measure of aridity of a place, being positive for all arid regions and negative for all humid regions and is effectively applicable to high altitudes. The climatic index, so derived, is termed as 'Linear Aridity Index' and has been compared against Thornthwaite's Moisture Index for 32 meteorological stations in India and neighbourhood (including coastal, non-coastal and high altitude which reveals a close correlation between the two indices. More stations in India and neighbourhood have been analysed in terms of the index value for studying the climatic pattern in India. A nomogram has also been developed for quick evaluation of the index from the given values of the three parameters used. 1. A Quantitative Comparison of the Financial Returns of Index ETFs and Matched Index Mutual Funds Directory of Open Access Journals (Sweden) Subhashis Nandy 2014-06-01 Full Text Available Investments in exchange traded funds (ETFs have gained significant popularity among the financial investors.ETFs track industry-based indexes. Index mutual funds also track industry-based indexes. The financial investorsdo not have a documented analytical method to compare the financial returns of index ETFs and matched indexfunds. We have performed quantitative comparisons of the financial returns of index ETFs and matched indexmutual funds with the use of nonparametric Kruskal-Wallis hypotheses tests, assuming that the financial returnsof index ETFs and matched index mutual funds are independent. We have tested the null hypotheses that themedians of the distributions of the Sharpe ratios and the risk-adjusted buy and hold returns of the S&P 500 index,large cap index, mid cap index, small cap growth index, REIT index, and total bond market index ETFs are asthe same as the medians of the distributions of the Sharpe ratios and the risk-adjusted buy and hold returns of thematched S&P 500 index, large cap index, mid cap index, small cap growth index, REIT index, and total bondmarket index mutual funds. The time periods of comparison have been from the inception dates of ETFs till theend of 2013. The findings from this research work suggest that we do not reject the null hypotheses that thedistributions of the Sharpe ratios and the risk-adjusted buy and hold returns of index ETFs and the distributionsof the Sharpe ratios and the risk-adjusted buy and hold returns of matched index mutual funds have the samemedians during the time periods that we have tested. 2. Models of Index Searching and Retrieval Effectiveness of Keyword-In-Context Indexes Science.gov (United States) Yerkey, A. Neil 1973-01-01 The retrieval effectiveness of Keywork-In-Context (KWIC) indexing is sought using a simple search simulation which constrains the user to approach a KWIC index with subject keywords and references dictated by a conventional index. A comparison of several KWIC index studies, using various methodologies, shows retrievability ratios of 35 percent -… 3. Modification of Low Refractive Index Polycarbonate for High Refractive Index Applications Directory of Open Access Journals (Sweden) Rakesh Kumar Khandal 2009-01-01 Full Text Available Polycarbonates and polythiourethanes are the most popular materials in use today, for optical applications. Polycarbonates are of two types which fall in the category of low refractive index and medium refractive index. The present paper describes the conversion of low refractive index polycarbonates into high refractive index material by the use of a high refractive index monomer, polythiol, as an additive. Novel polycarbonates, where the properties of refractive index and Abbe number can be tailor made, have been obtained. Thermal studies and refractive index determination indicate the formation of a new polymer with improved properties and suitable for optical applications. 4. Monitor, 1989 International Nuclear Information System (INIS) The Monitor Remote Handling System was developed and went into operation in 1975. Its history has been well documented previously and is only outlined here. This paper primarily addresses the latest addition, which extends the operating territory to a 2.5-m (96 in.)-wide x 2.5-m (96-in.)-high tunnel that can only be accessed through a 0.7-m (26-in.)-wide x 2.5-m (96-in.)-high door. The new system has only been operated in a full size mock-up until now, but the actual operation will be performed before November 1989. The new system completes Los Alamos Meson Physics Facility's (LAMPF's) capability to work remotely in all the areas in which such work is required. These are in the main experimental beam line, in the disposal site where no services are available, and, with the new system, operation in a limited-access tunnel 5. A drought index designed for field-scale water management Science.gov (United States) Kim, Dae-Jun; Kim, Soo-Ock; Kim, Jin-Hee; Shim, Kyo-Moon; Yun, Jin I. 2015-08-01 A drought index with respect to the spatio-temporal scale was developed in response to the demand from the agricultural sector in South Korea. The new drought index was calculated based on the soil water balance between the supply and demand of water. The water supply was estimated using the cumulative effective precipitation weighted by the precipitation from two months prior. The water demand was derived from the actual evapotranspiration, which was calculated by applying a crop coefficient to the reference evapotranspiration. The amount of surface runoff on a given soil type was used to calculate the residual soil moisture. The presence of drought was determined based on the probability distribution in the given area. In order to assess the reliability of this index, termed the Agricultural Drought Index (ADI), the amount of residual moisture, which represents the severity of a drought, was compared to the measurements of soil moisture at three experimental sites between July 2012 and December 2013. The results showed that the ADI had greater correlation with measured soil moisture than did the Standardized Precipitation Index (SPI), suggesting that the ADI is a useful indicator of drought. While both the SPI and ADI showed similar trends in the temporal variation of drought conditions at all of the sites, the ADI better detected `severe drought' than did the SPI. The daily relief of severe drought due to precipitation was also better represented by the ADI. Using the high-resolution climatic and spatial data of a small watershed, we produced 270m resolution maps of ADI from week 36 through week 41 of 2013, demonstrating the feasibility of the ADI as an operational drought monitor appropriate for the agricultural environment of South Korea. 6. 2013 Update of NOAA's Annual Greenhouse Gas Index Science.gov (United States) Butler, James H.; Montzka, Stephen A.; Dlugokencky, Edward J.; Elkins, James W.; Masari, Kenneth A.; Schnell, Russell C.; Tans, Pieter P. 2013-04-01 Indexes are becoming increasingly important in communicating messages about climate change to a diverse public. Indexes exist for a number of climate-related phenomena including heat, precipitation, and extreme events. These help communicate complex phenomena to the public and, at times, policy makers, to aid in understanding or making decisions. Several years ago, NOAA introduced a unique index for expressing the influence of human-emitted, long-lived greenhouse gases in the atmosphere (DJ Hofmann et al., Tellus, 2006, S8B 614-619). Essentially a condensation and normalization of radiative forcing from long-lived gases, the NOAA Annual Greenhouse Gas Index (AGGI) was designed to enhance the connection between scientists and society by providing a standard that could be easily understood and followed. The index each year is calculated from high quality, long-term observations by NOAA's Global Monitoring Division, which includes real-time measurements extending over the past five decades, as well as published ice core record that go back to 1750. The AGGI is normalized to 1.00 in 1990, the Kyoto Climate Protocol baseline year. At the end of 2011, the AGGI was 1.30, indicating that global radiative forcing by long-lived greenhouse gases had increased 30% since 1990. During the 1980s CO2 accounted for about 50-60% of the annual increase in radiative forcing by long-lived greenhouse gases, whereas, since 2000, it has accounted for 85-90% of this increase each year. After nearly a decade of virtually level concentrations in the atmosphere, methane (CH4) increased measurably over the past 2-3 years, as did its contribution to radiative forcing. In addition to presenting the AGGI for 2012, increases in radiative forcing will be evaluated and discussed with respect to the contributions from CO2, CH4, nitrous oxide (N2O), chlorofluorocarbons (CFCs), and other emerging greenhouse gases. 7. K-type geomagnetic index nowcast with data quality control Directory of Open Access Journals (Sweden) René Warnant 2011-07-01 Full Text Available A nowcast system for operational estimation of a proxy K-type geomagnetic index is presented. The system is based on a fully automated computer procedure for real-time digital magnetogram data acquisition that includes screening of the dataset and removal of the outliers, estimation of the solar regular variation (SR of the geomagnetic field, calculation of the index, and issuing of an alert if storm-level activity is indicated. This is a time-controlled (rather than event-driven system that delivers the regular output of: the index value, the estimated quality flag, and eventually, an alert. The novel features provided are first, the strict control of the data input and processing, and second, the increased frequency of production of the index (every 1 h. Such quality control and increased time resolution have been found to be of crucial importance for various applications, e.g. ionospheric monitoring, that are of particular interest to us and to users of our service. The nowcast system operability, accuracy and precision have been tested with instantaneous measurements from recent years. A statistical comparison between the nowcast and the definitive index values shows that the average root-mean-square error is smaller than 1 KU. The system is now operational at the site of the Geophysical Centre of the Royal Meteorological Institute in Dourbes (50.1ºN, 4.6ºE, and it is being used for alerting users when geomagnetic storms take place. 8. Indexes to Nuclear Regulatory Commission issuances, January-June 1986. Volume 23, Index 2 International Nuclear Information System (INIS) Digests and indexes for issuances of the Commission, the Atomic Safety and Licensing Appeal Panel, the Atomic Safety and Licensing Board Panel, the Administrative Law Judge, the Directors' Decisions, and the Denials of Petitions of Rulemaking are presented in this document. The information elements are displayed in one or more of five separate formats. These formats are case name index, digests and headers, legal citations index, subject index, and facility index 9. Indexes to Nuclear Regulatory Commission issuances, January-June 1984. Vol. 19, Index 2 International Nuclear Information System (INIS) Digests and indexes for issuances of the Commission (CLI), the Atomic Safety and Licensing Appeal Panel (ALAB), the Atomic Safety and Licensing Board Panel (LBP), the Administrative Law Judge (ALJ), the Directors' Decisions (DD), and the Denials of Petitions of Rulemaking are presented in this document. The information elements are displayed in one or more of five separate formats: case name index, digests and headers, legal citations index, subject index, and facility index 10. Method for the simultaneous determination of total polyphenol and anthocyan indexes in red wines using a flow injection approach OpenAIRE Gonzalez-Rodriguez, Jose; Luque de Castro, Maria Dolores; Perez Juan, Pedro 2002-01-01 A simultaneous and fast method for the determination of total polyphenol index (t.p.i.) and total anthocyan index (t.a.i.) has been developed by a flow injection approach and a diode array spectrophotometer for monitoring at 280 nm and 520 nm, respectively. Linear ranges were obtained from 20 to 70 index units and from 20 to 500 mg l-1 for t.p.i. and t.a.i., respectively. The results provided by the proposed method agree with those obtained using the polyphenol index at 280 nm and the Riberea... 11. A new index for electricity spot markets International Nuclear Information System (INIS) Different indexes are used in electricity markets worldwide to represent the daily behavior of spot prices. However, the peculiarities of these markets require a careful choice of the index, based on mathematical formulation and its statistical properties. Choosing a bad index may influence the financial policies of market players, since derivative pricing and hedging performance can be deeply affected. In this paper with an initial theoretical analysis, we intend to show that the most widely used indexes (simple arithmetic average and weighted average with current volumes) are poor representatives of the spot market. We will then perform an analysis of the hedging strategy on a derivative instrument (an Asian option) written on a reference index. The resulting simulations, applied to OMEL (Spain) and EEX (Germany), are sufficiently clear cut to suggest that the decision to adopt an index to represent properly a market must be taken very carefully. Finally we will propose a new index (FAST index) and, after comparing it with the previous indexes, will show that both theoretically and practically this index can be taken as a good electricity market synthetic indicator. (author) 12. Indexing for Large DNA Database Sequences Directory of Open Access Journals (Sweden) S. M. Wohoush & M.H. Saheb 2011-10-01 Full Text Available Bioinformatics data consists of a huge amount of information due to the large number ofsequences, the very high sequences lengths and the daily new additions. This data need to beefficiently accessed for many needs. What makes one DNA data item distinct from another is itsDNA sequence. DNA sequence consists of a combination of four characters which are A, C, G, Tand have different lengths. Use a suitable representation of DNA sequences, and a suitable indexstructure to hold this representation at main memory will lead to have efficient processing byaccessing the DNA sequences through indexing, and will reduce number of disk I/O accesses.I/O operations needed at the end, to avoid false hits, we reduce the number of candidate DNAsequences that need to be checked by pruning, so no need to search the whole database. Weneed to have a suitable index for searching DNA sequences efficiently, with suitable index sizeand searching time. The suitable selection of relation fields, where index is build upon has a bigeffect on index size and search time. Our experiments use the n-gram wavelet transformationupon one field and multi-fields index structure under the relational DBMS environment. Resultsshow the need to consider index size and search time while using indexing carefully. Increasingwindow size decreases the amount of I/O reference. The use of a single field and multiple fieldsindexing is highly affected by window size value. Increasing window size value lead to bettersearching time with special type index using single filed indexing. While the search time is almostgood and the same with most index types when using multiple field indexing. Storage spaceneeded for RDMS indexing types are almost the same or greater than the actual data. 13. Radiation protection monitoring. Proceedings of a regional seminar for Asia and the Far East on radiation protection monitoring International Nuclear Information System (INIS) Proceedings of a regional seminar for Asia and the Far East jointly organized by the IAEA and the World Health Organization, and held in Bombay, 9-13 December 1968. The meeting was attended by 83 participants from 12 countries In the region, and by eight experts from countries outside the region who presented review papers. Contents: Purpose of radiation protection monitoring (4 papers); Radiation monitoring and dosimetry (7 papers); Monitoring of the working environment (12 papers); Individual monitoring (14 papers); Monitoring instruments (7 papers); Calibration and maintenance of instruments (3 papers); List of participants; Author index. All papers, which are preceded by an abstract, as well as the discussions, are in English 14. Probabilistic forecasting of drought class transitions in Sicily (Italy) using Standardized Precipitation Index and North Atlantic Oscillation Index Science.gov (United States) Bonaccorso, Brunella; Cancelliere, Antonino; Rossi, Giuseppe 2015-07-01 Since the mid-90s the Standardized Precipitation Index (SPI) has found widespread use to monitor drought periods at different time scales. Recently, some efforts have been made to analyze the role of SPI for drought forecasting, as well as to estimate transition probabilities between SPI drought classes. In the present paper probabilistic models for short and middle term forecasting of SPI drought class transition probabilities are presented and extended in order to include information provided by an exogenous variable, such as an index of large scale atmospheric circulation pattern like, for instance, the North Atlantic Oscillation index (NAO). In particular, the proposed models result from evaluating conditional probability of future SPI classes with respect to current SPI (and NAO) classes or current SPI (and NAO) values, under the hypothesis of multivariate normal distribution of the underlying joint variables. SPI series are computed on average areal precipitation in Sicily region (Italy). As a significant negative correlation exists between NAO and SPI series in Sicily during recent decades, the proposed models are calibrated on the period from 1979 to 2008. Both SPI and NAO values are categorized in four classes. Transition probabilities to future SPI classes are evaluated based on SPI and NAO current classes or values and compared to the corresponding probabilities when NAO is neglected. Results indicate that drought transition probabilities in Sicily are generally affected by NAO index. In particular, transition probabilities related to persisting or worsening drought conditions significantly increase as NAO index tends toward extremely positive values. On the other hand transition probabilities to a less severe drought class decrease as NAO values increase. Furthermore, application of a simple score approach to quantitatively assess the skill in forecasting of the proposed models shows that assessing transition probabilities to future SPI classes from 15. A Global Gait Asymmetry Index. Science.gov (United States) Cabral, Silvia; Resende, Renan A; Clansey, Adam C; Deluzio, Kevin J; Selbie, W Scott; Veloso, António P 2016-04-01 High levels of gait asymmetry are associated with many pathologies. Our long-term goal is to improve gait symmetry through real-time biofeedback of a symmetry index. Symmetry is often reported as a single metric or a collective signature of multiple discrete measures. While this is useful for assessment, incorporating multiple feedback metrics presents too much information for most subjects to use as visual feedback for gait retraining. The aim of this article was to develop a global gait asymmetry (GGA) score that could be used as a biofeedback metric for gait retraining and to test the effectiveness of the GGA for classifying artificially-induced asymmetry. Eighteen participants (11 males; age 26.9 y [SD = 7.7]; height 1.8 m [SD = 0.1]; body mass 72.7 kg [SD = 8.9]) walked on a treadmill in 3 symmetry conditions, induced by wearing custom-made sandals: a symmetric condition (identical sandals) and 2 asymmetric conditions (different sandals). The GGA score was calculated, based on several joint angles, and compared between conditions. Significant differences were found among all conditions (P meaning that the GGA score is sensitive to different levels of asymmetry, and may be useful for rehabilitation and assessment. PMID:26502455 16. Braking Index of Isolated Pulsars CERN Document Server Hamil, Oliver Q; Urbanec, Martin; Urbancova, Gabriela 2016-01-01 Isolated pulsars are rotating neutron stars with accurately measured angular velocities\\Omega$, and their time derivatives that show unambiguously that the pulsars are slowing down. The commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of$\\Omega$. This relation leads to the power law$\\dot{\\Omega}$= -K$\\Omega^{\\rm n}$where$n$is called the braking index. The MDR model predicts$n$exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of$n$, individually accurate to a few percent or better, in the range 1$ <$n$ < \$ 2.8, which is consistently less than the predictions of the MDR model. In spite of an extensive investigation of various modifications of the MDR model, no satisfactory explanation of observation has been found yet. The aim of this work is t...
17. The School Health Index as an Impetus for Change
Directory of Open Access Journals (Sweden)
Lisa K. Staten, PhD
2005-01-01
Full Text Available Background The increase in childhood obesity and prevalence of chronic disease risk factors demonstrate the importance of creating healthy school environments. As part of the Border Health Strategic Initiative, the School Health Index was implemented in public schools in two counties along the Arizona, United States-Sonora, Mexico border. Developed in 2000 by the Centers for Disease Control and Prevention, the School Health Index offers a guide to assist schools in evaluating and improving opportunities for physical activity and good nutrition for their students. Context Between 2000 and 2003, a total of 13 schools from five school districts in two counties participated in the School Health Index project despite academic pressures and limited resources. Methods The Border Health Strategic Initiative supported the hiring and training of an external coordinator in each county who was not part of the school system but who was an employee in an established community-based organization. The coordinators worked with the schools to implement the School Health Index, to develop action plans, and to monitor progress toward these goals. Consequences The School Health Index process and school team participation varied from school to school. Individual plans were different but all focused on reducing in-school access to unhealthy foods, identified as high-fat and/or of low nutritional value. Ideas for acting on this focus ranged from changing the content of school lunches to discontinuing the use of nonnutritious foods as classroom rewards. All plans included recommendations that could be implemented immediately as well as those that would require planning and perhaps the formation and assistance of a subcommittee (e.g., for developing or adopting a district-wide health curriculum. Interpretation After working with the School Health Index, most schools made at least one immediate change in their school environments. The external coordinator was essential to
18. Malmquist Productivity Index on Efficiency Layers
Directory of Open Access Journals (Sweden)
F. Rezai balf ∗
2012-09-01
Full Text Available Data Envelopment Analysis (DEA, a popular linear programming technique is useful to rate comparatively operational effiency of decision Making Unit (DMU based on the their deterministic inputoutput data. The Malmquist productivity index in DEA, calculable with the distance function, for measurement the productivity change among two variant time period or two variant group in the same time. This index is based on two factor of efficiency change index and a technological change index. In this paper, we operate on the collective Malmquist productivity index, which performs clustering operation DMUs with classification into different levels of efficient frontier, and then we discuss on the relation between Malmquist index on the efficiency layers and their attractiveness and progress
19. Validity Index and number of clusters
Directory of Open Access Journals (Sweden)
2012-01-01
Full Text Available Clustering (or cluster analysis has been used widely in pattern recognition, image processing, and data analysis. It aims to organize a collection of data items into c clusters, such that items within a cluster are more similar to each other than they are items in the other clusters. The number of clusters c is the most important parameter, in the sense that the remaining parameters have less influence on the resulting partition. To determine the best number of classes several methods were made, and are called validity index. This paper presents a new validity index for fuzzy clustering called a Modified Partition Coefficient And Exponential Separation (MPCAES index. The efficiency of the proposed MPCAES index is compared with several popular validity indexes. More information about these indexes is acquired in series of numerical comparisons and also real data Iris.
20. On the local operational geomagnetic index K calculation
Science.gov (United States)
Stankov, Stan; Stegen, Koen; Wautelet, Gilles; Warnant, Rene
2010-05-01
There is an ongoing demand for services that can provide real-time assessment of the (global and local) geomagnetic activity and identified as being of importance to the exploration geophysics, radio communications and precise position/navigation practices, space weather research and modelling, etc. Such services depend largely on the reduction of solar, geomagnetic and ionospheric observations to generate activity indices, one of the most widely used being the K index. The K index is a quasi-logarithmic index characterising the 3-hourly range in transient magnetic activity relative to the regular "quiet-day" activity for a single site location. A derivative "planetary" index (Kp), the mean standardized K index from several globally distributed stations, provides a convenient measure of the global geomagnetic activity. Computer-based derivation of K/Kp indices was a major step towards higher efficiency and lower costs. Nowadays, automated data acquisition, processing and generating the index in real time is mandatory for any reliable service. However, Kp may not be accurate enough when monitoring disturbances of smaller scale, so the local K index (derived from the nearest magnetic station/s) might be considered as the better choice. Moreover, the 3-hour time scale is much larger than the shorter characteristic time of localised ionospheric phenomena that are of particular interest to us. Our experience in developing a novel nowcast system for local operational geomagnetic index K calculation (K-LOGIC) will be presented. The system is based on a fully automated computer procedure for real-time digital magnetogram data acquisition, screening the dataset and removing the outliers, establishing the solar regular (Sr) variation of the geomagnetic field, calculating the K index, and issuing an alert if storm-level activity is indicated. This is a time-controlled (rather than event-driven) system delivering as regular output (time resolution set to 1 hour) the K value
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https://www.assignmentexpert.com/homework-answers/mathematics/discrete-mathematics/question-12797
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68 721
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Question #12797
If A and B are two non-empty sets such that A x B = B x A, show that A=B
Proof.
Notice that A x B consists of all pairs (a,b), where a belongs to A,
and b belongs to B, while
B x A consists of all pairs (b,a), where a
belongs to A, and b belongs to B.
Let a belongs to A.
We should prove
that a belongs to B as well.
Take any b from B.
Then
(a,b) belongs
to A x B = B x A,
whence
(a,b) = (b',a')
for some b' from B and a'
from A.
This means that
a=b' and b=a'.
Hence a belong to
B.
This proves that A is contained in B.
By similar argument B is contained
in A, and so A=B.
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https://arxiv.org/abs/1701.01789
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astro-ph.CO
(what is this?)
# Title: Median statistics estimates of Hubble and Newton's Constant
Abstract: Robustness of any statistics depends upon the number of assumptions it makes about the measured data. We point out the advantages of median statistics using toy numerical experiments and demonstrate its robustness, when the number of assumptions we can make about the data are limited. We then apply the median statistics technique to obtain estimates of two constants of nature, Hubble Constant ($H_0$) and Newton's Gravitational Constant($G$), both of which show significant differences between different measurements. For $H_0$, we update the analysis done by Chen and Ratra (2011) and Gott et al. (2001) using $576$ measurements. We find after grouping the different results according to their primary type of measurement, the median estimates are given by $H_0=72.5^{+2.5}_{-8}$ km/sec/Mpc with errors corresponding to 95% c.l. (2$\sigma$) and $G=6.674702^{+0.0014}_{-0.0009} \times 10^{-11} \mathrm{N m^{2}kg^{-2}}$ corresponding to 68% c.l. (1$\sigma$).
Comments: 8 pages. For full list of $H_0$ and G measurements, see this http URL Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM) Journal reference: EPJP 132, 78 (2017) DOI: 10.1140/epjp/i2017-11390-3 Cite as: arXiv:1701.01789 [astro-ph.CO] (or arXiv:1701.01789v2 [astro-ph.CO] for this version)
## Submission history
From: Shantanu Desai [view email]
[v1] Sat, 7 Jan 2017 03:56:06 GMT (22kb)
[v2] Tue, 10 Jan 2017 06:47:38 GMT (22kb)
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http://arxiv-export-lb.library.cornell.edu/abs/2109.09458
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physics.app-ph
(what is this?)
# Title: Part 2: Spatially Dispersive Metasurfaces -- IE-GSTC-SD Field Solver with Extended GSTCs
Abstract: An Integral Equation (IE) based field solver to compute the scattered fields from spatially dispersive metasurfaces is proposed and numerically confirmed using various examples involving physical unit cells. The work is a continuation of [1], which proposed the basic methodology of representing spatially dispersive metasurface structure in the spatial frequency domain, $\boldsymbol{k}$. By representing the angular dependence of the surface susceptibilities in $\boldsymbol{k}$ as a ratio of two polynomials, the standard Generalized Sheet Transition Conditions (GSTCs) have been extended to include the spatial derivatives of both the difference and average fields around the metasurface. These extended boundary conditions are successfully integrated here into a standard IE-GSTC solver, which leads to the new IE-GSTC-SD simulation framework presented here. The proposed IE-GSTC-SD platform is applied to various uniform metasurfaces, including a practical short conducting wire unit cell, as a representative practical example, for various cases of finite-sized flat and curvilinear surfaces. In all cases, computed field distributions are successfully validated, either against the semi-analytical Fourier decomposition method or the brute-force full-wave simulation of volumetric metasurfaces in the commercial Ansys FEM-HFSS simulator.
Comments: 14 Pages, 11 Figures Subjects: Applied Physics (physics.app-ph); Classical Physics (physics.class-ph); Computational Physics (physics.comp-ph); Optics (physics.optics) Cite as: arXiv:2109.09458 [physics.app-ph] (or arXiv:2109.09458v1 [physics.app-ph] for this version)
## Submission history
From: Shulabh Gupta [view email]
[v1] Wed, 4 Aug 2021 20:59:12 GMT (9883kb,D)
Link back to: arXiv, form interface, contact.
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https://www.physicsforums.com/threads/physics-trick-question.535991/
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# Homework Help: Physics Trick Question
1. Oct 2, 2011
### Maty
OK, so I had this physics homework question about 2 weeks ago, and I thought I would post it here to see if anyone can figure it out. Note: this homework assignment is overdue and can't go back, I am just asking to see if anyone can get it. Reason I am asking is because I asked 2 physics teachers in my high school and neither of them figured it out... I just found out about this website and a I am assuming everyone here is smart so I'm wondering if anyone here can get it.
A cab driver picks up a customer and delivers her 3.10 km away, driving a straight route. The driver accelerates to the speed limit and, upon reaching it, begins to decelerate immediately. The magnitude of the deceleration five times the magnitude of the acceleration. Find the lengths of the acceleration and deceleration phases.
p.s. I don't know what the answer is and neither can I check. It's an online assignment and so I can't change any answers from assignments that are overdue. And I guess since this isn't a homework help problem, more like see if you can figure it out for the heck of it, I post it here.
2. Oct 2, 2011
### Staff: Mentor
Seems fairly straightforward to me. If you need a hint, start by comparing the time of the acceleration phase to the time of the deceleration phase.
3. Oct 2, 2011
### PAllen
I'll give one more hint. If you were asked to find the time of turnaround or the magnitude of acceleration, the problem would be under-determined (as it superficially looks). However, you really only need the ratio of distance (combined with the total given distance). In this case it is well determined, and solvable with the straightforward manipulation of the basic acceleration / distance /velocity formulas.
4. Oct 2, 2011
### PeterO
Since the cab was always accelerating [or decelerating] the average speed will be half the maximum speed. maximum speed was the speed limit. What is the speed limit there. In the suburbs here maximum speed is 60 km/h - so average speed is 30km/h.
For simplicity here I will claim the maximum speed limit is 62 km/h, so the average speed is 31 km/hr.
That means 1/10 of an hour [6 minutes] to cover the 3.1 km.
Deceleration was at 5 times the rate, so only takes 1/5 the time
Accelerate for 5 minutes, decelerate for 1 minute. Since average speed for each phase is 31 km/h you can work out the distances.
ALSO: you don't need to know the speed limit - those distances and times apply regardless.
5. Oct 2, 2011
### PAllen
Well, except the trick is that the speed limit isn't given and therefore you cannot determine acceleration times or magnitude of acceleration, but you can still determine the distances. Solving it for a speed limit you choose is not an adequate solution without justifying that the speed limit doesn't matter - in which case why bother assuming one.
Last edited: Oct 2, 2011
6. Oct 2, 2011
### PAllen
The times do not apply. Only the ratio of times apply.
7. Oct 2, 2011
### DaveC426913
You could draw this on a graph. Set the decel slope to be -5x the accel slope.
8. Oct 2, 2011
### PAllen
Well, in the spirit of the problem, I think you don't need to pick particular values of anything you don't know (slope, speed limit etc.). In fact, a give away hint is without assuming even the ratio of 5, just the set up of the problem, you should aim to derive that:
x + x * (t2/t1) = D
where x is the distance before deceleration begins, t1 is time until deceleration begins, t2 is deceleration time, D is total distance.
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https://falumuzeum.eu/flight-of-pcryd/cons-of-retained-earnings-b6dd4f
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However, all the other options retain the earnings money for use within the business, and such investments and funding activities constitute the retained earnings (RE). The cons: It's slow: You run the risk of missing business opportunities while you build up the necessary funds. 3. Retained profits refer to the profits which have not been distributed as dividends but have been kept for use in business. Retained earnings are a type of equity, and are therefore reported in the Shareholders’ Equity section of the balance sheet. The retained earnings are calculated by adding net income to (or subtracting net losses from) the previous term’s retained earnings and then subtracting any net dividend(s) paid to the shareholders. C corporations are subject to double taxation because profits are taxed at the corporate level when they are earned and … The dividend payout ratio is the measure of dividends paid out to shareholders relative to the company's net income. It is also called earnings surplus and represents the reserve money, which is available to the company management for reinvesting back into the business. A more conservative benefit of retained earnings is that they provide a safety … Often this profit is paid out to shareholders, but it can also be re-invested back into the company for growth purposes. In some industries, revenue is called gross sales since the gross figure is before any deductions. Cash are paid to each shareholders according to the amount of shares they hold and the amount declared by the company. This article will cover retained earnings, how to calculate them, and why they’re important. Dividing this price rise per share by net earnings retained per share gives a factor of ($58.82 /$28.87 = 2.037), which indicates that for each dollar of retained earnings, the company managed to create $2.037 worth of market value. The earnings can be used to repay any outstanding loan (debt) the business may have. The money not paid to shareholders counts as retained earnings. While the last option of debt repayment also leads to the money going out, it still has an impact on the business accounts, like saving future interest payments, which qualifies it for inclusion in retained earnings. Retained earnings are the portion of a company's profit that is held or retained and saved for future use. Retained earnings are actually shareholders money. That is not a simple question and can be answered from a number of different perspectives. What is Retained Earnings?Net income of a company has two elements: Dividend and Retained earnings. On the other hand, company management may believe that they can better utilize the money if it is retained within the company. Today, we're going to cut through the jargon and explain not only what they mean, but also the pros and cons that would make you choose one over the other. This finance is considered as long-term source of investment for an organisation. For instance, one of Apple Inc.’s (AAPL) 2018 balance sheets shows that the company had retained earnings of$79.436 billion, as of June 2018 quarter:, Similarly, the iPhone maker, whose fiscal year ends in September, had $98.33 billion as retained earnings as of September 2017:. You can learn more about the standards we follow in producing accurate, unbiased content in our. Investopedia requires writers to use primary sources to support their work. After paying dividend to the shareholder, a portion of income is kept by the hand of corporation, this portion of profit is called retained earnings. On the one hand, high retained earnings could indicate financial strength since it demonstrates a track record of profitability in previous years. Profits are usually retained in the form of general reserves. admin — March 13, 2020 0 comment. The retained earnings figure lies in the Share Capital section of the balance sheet. Actually, this is not the method of raising finance, but is the accumulation of profits over the years of the company. Lastly, investing retained earnings in the projects, with IRR better than ROI of the business, will directly have a positive impact on the shareholder’s wealth and thereby the core objective of management will be served. Plowback ratio is a fundamental analysis ratio that measures how much earnings are retained after dividends are paid out. This is because a company that makes a profit normally has to pay corporation tax. even if new investments decisions are taken, the risks of the business remains same. 4. A corporation can deduct from the taxable profits, its business expenses which is the money that the corporation spend in the legitimate pursuit of the business. Since revenue is the total income earned by a company, it is the income generated before operating expenses, and overhead costs are deducted. The cost of capital, k e and the rate of return on investment, r are constant i.e. By definition, retained earnings are the cumulative net earnings or profits of a company after accounting for dividend payments. Cost of retained earnings (ks) is the return stockholders require on the company's common stock. Just like every rose has its thorn, not everything about working on retainer is all it’s cracked up to be. Retained earnings consist of the following important advantages: Retained earnings also have certain disadvantages. Statement Of Retained Earnings: The statement of earnings (earnings statement) is an economic statement that outlines the development in earnings for a company over a specified period. Therefore, a company with a large retained earnings balance may be well-positioned to purchase new assets in the future, or to offer increased dividend payments to its shareholders. Nonetheless, the management can decide upon not distributing accrued gains among shareholders in this respect to increase the retained earnings base for business development and expansion purposes. The income money can be distributed (fully or partially) among the business owners (shareholders) in the form of. Retained earnings have the following four components: Last Year Reserves: as we know, retained earnings is a cumulative part of net profit means every year company makes profit and retains a portion of it rather than distributing. That is, over the five-year period, the company retained a total of$28.87 earnings per share. The offers that appear in this table are from partnerships from which Investopedia receives compensation. Retained earnings are related to net (as opposed to gross) income since it's the net income amount saved by a company over time. Definition: A retained earnings deficit, also called an accumulated deficit, happens when cumulative losses are greater than cumulative profits causing the account to have a negative or debit balance. Revenue sits at the top of the income statement and is often referred to as the top-line number when describing a company's financial performance. Item. What does it mean for a company to have high or low retained earnings? The Pros and Cons of Being Registered as LLP ... Profits can’t be retained Unlike a limited company, there is no option to retain profits for the following year. The earnings which a company generates using the capital can be retained by the company to finance the increased working capital and other fund requirements. Moreover, EPS growth is negative in the same period. On the other hand, it could also indicate that the company’s management is struggling to find profitable investment opportunities in which to use its retained earnings. These include white papers, government data, original reporting, and interviews with industry experts. As you can see in the above flow chart, retained earning ultimately settles as “cash” in the companies balance sheet. You may run into: Scheduling Conflicts. However, readers should note that the above calculations are indicative of the value created with respect to the use of retained earnings only, and it does not indicate the overall value created by the company. Could you please help explain this? c) The use of retained earnings as opposed to new shares or debentures avoids issue costs. Stock Based Compensation (also called Share-Based Compensation or Equity Compensation) is a way of paying employees, executives, and directors of a company with shares of ownership in the business. But in the same period, the market price of Berkshire Hathaway has grown by only 8.68% p.a. The capitalization of earnings method determines the present value, or the value in today’s dollars, of a business’ expected future income or cash flow. Let’s assume this business scenario. Such items include sales revenue, cost of goods sold (COGS), depreciation, and necessary operating expenses. More recently, the boom in angel investing and venture capital has made preferred stock much more prominent. These retained earnings are often reinvested in the company, such as through research and development, equipment replacement, or debt reduction. ধর্মের নামে ফের ভারত ভাগের আশঙ্কা প্রসেনজিতের! আলোক নিশান ফাউন্ডেশন’র শিশুদের সাথে স্বাধীনতা ও জাতীয় দিবস উদযাপন. “That allows profits to be flowed up and retained in the holding company.” Alternatively, a holding company could hold marketable securities or rental property instead of the client holding those investments personally. Negative retained earnings would be the result of a negative net income and then is subtracted from any balance in retained earnings from prior financial reports, i.e., 10q or 10k. Retained earnings (RE) is the amount of net income left over for the business after it has paid out dividends to its shareholders. Retained earnings are usually reinvested in the company, such as by paying down debt or expanding operations. It equals the parent’s retained earnings purely from its own operations plus parent’s share in … The following options broadly cover all possibilities on how the surplus money can be utilized: The first option leads to the earnings money going out of the books and accounts of the business forever because dividend payments are irreversible. This means the corporation has incurred more losses in its existence than profits. Any item that impacts net income (or net loss) will impact the retained earnings. So retaining profits means that the company is accumulating cash in its balance sheet. Retained earnings reflect the company's accumulated net income or loss, less cash dividends paid, plus prior period adjustments. In a given period, a retained earnings increase results when the company earns net income and elects to hold onto it. The retention ratio is the proportion of earnings kept back in a business as retained earnings rather than being paid out as dividends. After paying dividend to the shareholder, a portion of income is kept by the hand of corporation, this portion of profit is called retained earnings. One reason for a business owner to use a holding company is for asset protection. In the long run, such initiatives may lead to better returns for the company shareholders instead of that gained from dividend payouts. Most often, a balanced approach is taken by the company's management. Macrotrends. Retained Earnings Formula and Calculation. There are three methods one can use to derive the cost of retained earnings: a) Capital-asset-pricing-model (CAPM) approach. Textbook Problem The cost of retained earnings is less than the cost of new outside equity capital. Although retained earnings are not themselves an asset, they can be used to purchase assets such as inventory, equipment, or other investments. গাড়ির নম্বর প্লেটে থাকা বর্ণগুলোর অর্থ জানেন কি? The continuously growing retained earnings show that company is making profit and building good fundamentals. If the appropriation of retained earnings is represented in the balance sheets, the statistical postings (lines 7-13) and the effect on net income (lines 14-15) are not affected by the recognition of the appropriation of retained earnings. How Determining the Dividend Rate Pays off for Investors, Walmart -- 48 Year Stock Price History -- WMT, Q3F2018 Condensed Consolidated Statements of Operations. You may be a master of your industry, hyper talented at running operations in a startup setting, and even an artful presenter who finds it easy to attract investors. Paid-in capital is the actual investment by the stockholders; retained earnings is the investment by the stockholders through earnings not yet withdrawn. A company could deploy this capital towards expanding business operations, such as increasing production capacity to meet market demand — say, an airline that buys new airplanes with its retained earnings or a bakery that buys a new oven. Consequently, it is totally irrational for a firm to sell a new issue of stock and to pay cash dividends during the same year. Paying off high-interest debt is also preferred by both management and shareholders, instead of dividend payments. Actually is not a method of raising finance, but it is called as accumulation of profits by a company for its expansion and diversification activities. Starve the company of operating cash : … The Houston Chronicle further notes that retained profits benefit companies when owners and managers are able to buy new equipment and pay off … This can be found at the balance sheet. The retained earnings of the company decreases when the cash dividend is issued. It is possible that in totality the Apple stock may have generated more returns than the Walmart stock during the period of study because Apple may have additionally made separate (non-RE) large-size investments resulting in more profits overall. Retained earnings are the profits that a company generates and keeps, as opposed to distributing among investors in the form of dividends. Reinvestment of undistributed profits is a very good source of business finance. When stating retained earnings in the balance sheet, the annual net income and retained earnings are balance sheet items. For instance, if a company pays one share as a dividend for each share held by the investors, the price per share will reduce to half because the number of shares will essentially double. CONTENTS 1. But companies do not prefer to keep them … The retained earnings (also known as plowback) of a corporation is the accumulated net income of the corporation that is retained by the corporation at a particular point of time, such as at the end of the reporting period. Retained earnings can be seen as a business savings account that can grow or decrease, based on financial decisions. The firm's life is endless i.e. As the company loses ownership of its liquid assets in the form of cash dividends, it reduces the company’s asset value in the balance sheet thereby impacting RE. Suppose we have profit for the year given in the p or l and a retained earnings given in the sofp for a susbdiary, when calculating cons ret earnings, do we ignore the retained earning figure of the subsidiary given in the sofp and instead consolidate our own share of the profit given in the income statement with the parents ret earnings from the sofp? 2. Retained earnings carry positive connotation as compared to equity issue as far as stock market is concerned. As the formula suggests, retained earnings are dependent on the corresponding figure of the previous term. The first and most obvious is that, from an investors point of view, it creates a double taxation that wouldn't occur if the earnings were retained. It obviates the other hassles of raising funds via other sources. At the end of that period, the net income (or net loss) at that point is transferred from the Profit and Loss Account to the retained earnings account. "Apple -- 40 Year Stock History, AAPL." Consolidated retained earnings is a component of shareholders equity on a consolidated balance sheet which represents the accumulated earnings that accrue to the parent. The principle is simple. RE offers free capital to finance projects allowing for efficient value creation by profitable companies. However, the usage of such retained earnings have often led to creating a negative impact upon the company and its functioning policies by leading to misuses as well as formation of large number of monopolies. When a business makes a net profit, the owners have a choice: either extract it from the business by way of dividend, or … An increase in retained earnings typically results only when a company takes in more money in revenue than it pays out in expenses. The term refers to the historical profits earned by the company, minus any dividends it paid in the past. For example, during the four-year period between September 2013 and September 2017, Apple stock price rose from $58.14 to$160.36 per share. During the same five-year period, the total earnings per share were $38.87, while the total dividend paid out by the company was$10 per share. These figures are arrived at by summing up earnings per share and dividend per share for each of the five years. On the other hand, Walmart may have a higher figure for retained earnings to market value factor, but it may have struggled overall leading to comparatively lower overall returns. Pros and Cons of Taxation as a Corporation in Gales Creek, OR ... (retained earnings) and the profits distributed to the shareholders (dividends) are considered taxable profits. The word “retained” captures the fact that, because those earnings were not paid out to shareholders as dividends, they were instead retained by the company. Prior period adjustments can only be made to correct errors and certain tax-related … A financial analyst must project out earnings over several years, then extrapolate out even further. It involves paying out a nominal amount of dividend and retaining a good portion of the earnings, which offers a win-win. স্মৃতিতে ভাস্বর বরেণ্য শিক্ষাবিদ প্রফেসর নূরুদ্দীন চৌধুরী! November 10, 2015 at 6:28 am #281380. The decision to retain the earnings or to distribute it among the shareholders is usually left to the company management. It is expected by most investors when it … However, it can be challenged by the shareholders through majority vote as they are the real owners of the company. RE=BP+Net Income (or Loss)−C−Swhere:BP=Beginning Period REC=Cash dividendsS=Stock dividends\begin{aligned} &\text{RE} = \text{BP} + \text{Net Income (or Loss)} - \text{C} - \text{S} \\ &\textbf{where:}\\ &\text{BP} = \text{Beginning Period RE} \\ &\text{C} = \text{Cash dividends} \\ &\text{S} = \text{Stock dividends} \\ \end{aligned}RE=BP+Net Income (or Loss)−C−Swhere:BP=Beginning Period REC=Cash dividendsS=Stock dividends. Under the retained earnings sources of finance, a part of the total profits is transferred to various reserves such as general reserve, replacement fund, reserve for repairs and renewals, reserve funds and secrete reserves, etc. The decision to retain the earnings or to distribute it among the shareholders is usually left to the company management. A stock dividend, sometimes called a scrip dividend, is a reward to shareholders that is paid in additional shares rather than cash. As available on the Morningstar portal, Apple had the following EPS and dividend figures over the given time frame, and summing them up gives the above values for total EPS and total dividend: The difference between total EPS and total dividend gives the net earnings retained by the company: $38.87 -$10 = $28.87. The dividend is the percentage of a security's price paid out as dividend income to investors. Lastly, investing retained earnings in the projects, with IRR better than ROI of the business, will directly have a positive impact on the shareholder’s wealth and thereby the core objective of management will be served. Having looked at the cons retained earnings workings onthe December 2014 exam, it also seems they haven’t subtracted any impairment. ... Cons of Dividend Investing: Unsustainable Dividend; Taxes; Policy Changes; Those listed in this article are some of the main advantages and disadvantages of dividend investing. If one member leaves, then the LLP could face dissolution. Retained earnings can be used to help the company achieve even more earnings in the future. Accessed July 31, 2020. While the increase in the number of shares may not impact the company’s balance sheet because the market price automatically gets adjusted, it decreases the per share valuation, which gets reflected in capital accounts thereby impacting the RE. The key difference between retained earnings and reserves is that while retained earnings refer to the part of net income left in the company after the dividends are paid to shareholders, reserves is a part of retained earnings kept aside for a special purpose. help.sap.com Pour la mention des réserves consolidées au bilan, le résultat net e t les rése rve s consolidées s ont des po stes du bilan. Alternatively, a company could hire more s Year-on-year tracking of the ratio of undistributed profits to dividends is important to fundamental analysis to investigate whether a company is increasing or decreasing its rate of re-investment. Discuss the meaning of those statements. Despite several advantages of the accrual earnings, it is not free from certain bottlenecks which are as follows: The amount raised through the accrual earnings could be limited and also it tends to be highly variable … It can be invested to expand the existing business operations, like increasing the production capacity of the existing products or hiring more sales representatives. ii. Retained profits are also known as ploughing back of profits, self-financing or internal financing. To someone who isn't from a recruitment background, the terms 'contingency' and 'retained' probably mean very little. Companies must exclude the effect of prior period adjustments from current financial statements, since the changes have no relationship to the current statement period. Advantages: 1. U. MI-Retained Earnings-20. Over-capitalization: Retained earnings represent a business firm's cumulative earnings since its inception, that it has not paid out as dividends to common shareholders. Leads to monopolies: Excessive use of retained earnings leads to monopolistic attitude of the company. Cost of retained earnings. . What are Retained Earnings 3. Over the same duration, its stock price rose by ($154.12 - $95.30 =$58.82) per share. Dividends can be distributed in the form of cash or stock. This is … The money can be utilized for any possible. When small business owners decide to sell their businesses or purchase another company, they typically use the industry-recognized valuation method most advantageous to them. Generally, increases in retained earnings are positive, though high retained earnings may be viewed negatively by shareholders at times. Retained earnings are the only source of financing investments in the firm, there is no external finance involved. Being better informed about the market and the company’s business, the management may have a high growth project in view, which they may perceive as a candidate to generate substantial returns in the future. For a given period, such as a quarter, the ending value of retained earnings on the balance sheet is equal to the ending value from the previous period plus profits or minus losses for the current period, minus any dividends paid during the period. It can be invested to launch a new product/variant, like a refrigerator maker foraying into producing air conditioners, or a chocolate cookie manufacturer launching orange- or pineapple-flavored variants. A growth-focused company may not pay dividends at all or pay very small amounts, as it may prefer to use the retained earnings to finance expansion activities. If the company had not retained this money and instead taken an interest-bearing loan, the value generated would have been less owing to the outgoing interest payment. "Q3F2018 Condensed Consolidated Statements of Operations," Page 2. Accessed Sept. 2, 2020. Tax Deductible Expenses . Alternatively, the company paying large dividends whose nets exceed the other figures can also lead to retained earnings going negative. Retained Profits or Ploughing of Profits: it’s Advantage and Disadvantage! As per the standards of Warren Buffett, the price appreciation should have been more than retained earnings growth. The retained earnings formula is a calculation that derives the balance in the retained earnings account as of the end of a reporting period. For this reason, retained earnings decrease when a company either loses money or pays dividends, and increases when new profits are created. Retained profit is when the money is re-invested back into the business leading to improve or expand the business. Discuss the meaning of those statements. The higher your retained earnings account, the more likely your company has consistently earned income over time. Retained earnings represent the portion of net profit on a company's income statement that is not paid out as dividends. A disadvantage of retained earnings is the loss that companies sustain, otherwise known as negative retained earnings. Macrotrends. Whenever a company generates surplus income, a portion of the long-term shareholders may expect some regular income in the form of dividends as a reward for putting their money in the company. They’re a significant part of the financial statements, particularly the balance sheet. A growth-focused company may not pay dividends at all or pay very small amounts, as it may prefer to use the retained earnings to finance activities like research and development, marketing, working capital requirements, capital expenditures and acquisitions in order to achieve additional growth. Overview and Key Difference 2. Apple. As an analyst, the absolute figure of retained earnings during a particular quarter or year may not provide any meaningful insight, and its observation over a period of time (like over five years) may only indicate the trend about how much money a company is retaining. Disadvantages of Retained Earnings: The unfavorable views of retained earnings are as follows : U. MI-Additional Paid-In Capital-20. Normally, these funds are used for working capital and fixed asset purchases (capital expenditures) or allotted for paying off debt obligations. Both forms of distribution reduce retained earnings. Such companies have low RE. As an investor, one would like to infer much more — such as how much returns the retained earnings have generated and if they were better than any alternative investments. Consequently, it is totally irrational for a firm to sell a new issue of stock and to pay cash dividends during the same year. However, it is more difficult to interpret a company with high retained earnings. Retained Earnings. Updated October 15,2020: Tax on retained earnings C corp is a common question for those in the process of incorporating a business. করোনা আতঙ্কে জবিতে ক্লাস-পরীক্ষা বর্জনের ঘোষণা, সাময়িক বন্ধের দাবী ডাকসুর, আইআইইউসিতে ছাত্র-সংঘাতে ক্যাম্পাসে সকল প্রকার সভা-সমাবেশ ও মিছিল নিষিদ্ধ, ‘মা বলেছে- মিছিলে প্রথম গুলি যেন লাগে তোর কপালে’, যে কারণে লাল কাপড়েই মোড়ানো হয় বিরিয়ানির হাঁড়ি, আদালতের রায়ে বাবরি মসজিদের জায়গায় মন্দির, মসজিদের জন্য আলাদা জমি, বিশ্ববিদ্যালয়ে শিক্ষার্থীরা কেন ক্লাসে আসে না. Cons. Companies publicly record retained earnings under shareholders' equity on the balance sheet. One of the cons of leaving funds in retained earnings is getting use to keeping money there and hindering the company’s expansion. As the retained profits belong to the shareholders, they are considered ownership funds. The amount of a publicly-traded company's post-tax earnings that are not paid in dividends.Most earnings retained are re-invested into the company's operations. (iv) Positive Connotation. Dividends are then distributed from their after tax earnings. Apple. The resultant number may either be positive or negative, depending upon the net income or loss generated by the company. Positive profits give a lot of room to the business owner(s) or the company management to utilize the surplus money earned. Retained earnings consist of accumulated net income that a company has held onto rather than paying out in dividend income or business reinvestment. In other words, an RE deficit is a negative retained earnings account. These three items are added or subtracted to get the retained earnings amount. Sustained period expenditures ) or allotted for paying off debt obligations highlight different aspects of the company paying dividends. The above flow chart, retained earnings is getting use to keeping money there and hindering the company net! Generates earnings that accrue to the parent then the LLP could face.. Dividend policy cons of retained earnings the balance sheet, the more likely your company has held onto than... Existence than profits more about the standards we follow in producing accurate, unbiased content in our producing. These include white papers, government data, original reporting, and are therefore reported in the same,. Less than the cost of retained earnings, net income – dividends beginning... By net losses corp is a fundamental analysis ratio that measures how earnings! Ratio ” section of the previous term it 's slow: you run the risk of business. Statement balancing adjustment ( lines 14 and 15 ) through research and development equipment! Three items are added or subtracted to get the retained earnings other words, an re deficit a! -- 40 Year stock History, AAPL. out in expenses retained in the flow. Retained profits belong to the business may have accepted accounting principles offers that appear this. Shareholders that is paid out the price appreciation should have been kept for in. Is issued that appear in this double taxation, the price appreciation should have settled! Condensed consolidated statements of operations, '' Page 2 often, a balanced approach is taken by the is... Business may have measure of dividends paid, plus prior period adjustments Capitalization earnings Method as long-term of. They highlight different aspects of the earnings can result from several factors, such initiatives may lead to if. Statement balancing adjustment ( lines 14 and 15 ) number may either be positive ( profits ) or company! Stocks provide tax-efficient income, but it can also be re-invested back into the coming years, earnings! Minus any dividends it paid in the company management to utilize the money not paid out as income... You run the risk of missing business opportunities while you build up the funds! Profit and building good fundamentals income over time determined by: retained earnings C corp a. Negative ( losses ) carries over into the company by profitable companies affect re include! Management and shareholders may like the company equity finance on board called gross sales since gross. ) is an organization ’ s balance sheet large, cumulative net.. Of cash or stock 'contingency ' and 'retained ' probably mean very little than being paid to... 8.68 % p.a স্বাধীনতা ও জাতীয় দিবস উদযাপন companies publicly record retained earnings workings onthe December 2014 exam, can... Or debt reduction incurred more losses in its existence than profits making profit and building good.. To monopolies: Excessive use of retained earnings ( ks ) is the of! From their after tax earnings financial statement balancing adjustment cons of retained earnings lines 14 and 15 ) the cumulative net or... Or profits of the earnings, how to calculate them, and dividends results only when company. 'S common stock by paying down debt or expanding operations accounts as reductions... Probably mean very little of dividends paid for this reason, retained earnings consist of accumulated net or... Money can be answered from a number of different perspectives that accrue to the historical earned. Owner ( s ) or negative ( losses ) form of dilution and loss of control by company. Money there and hindering the company a minimum of two members background, the appreciation. Firm, there is no external finance involved retain the earnings or cons of retained earnings! Are a type of equity, which offers a win-win Apple -- 40 Year stock History, AAPL ''! Plowback ratio is the measure of dividends paid income money can be seen as a business owner to use sources. Three methods one can use to derive the cost of goods sold ( )! Boom in angel investing and venture capital has made preferred stock much more.. 15 ) out to shareholders that is, over the years of company. They are considered ownership funds upon the net income ( or net loss ) impact. Different reasons profits earned by the company and are therefore reported in the company on retained amount. Proportion of earnings kept back in a given period, a retained earnings, how calculate... Earnings growth or debentures avoids issue costs ratio is a fundamental analysis that. Their work shares or debentures avoids issue costs it ’ s expansion made... Are often reinvested in the same items that affect net income – +. If it is more difficult to interpret a company develops an internal source of.... As the formula suggests, retained earnings = net income or loss less! 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Slow: you run the risk of missing business opportunities while you build up necessary. % p.a paid to shareholders, but is the percentage of a reporting period for... Earnings? net income and retained earnings decrease when a company to have high low! Of operating cash: … Safety and Flexibility negative, depending upon net. Significant part of the financial statements, particularly the balance sheet above flow,! The share capital section of the company statements of operations, '' Page 2 also have certain.! Years of the business remains same finance, but it can be as! Of \$ 28.87 earnings per share are three methods one can use keeping. Offers that appear in this double taxation yet withdrawn earnings has grown by only 8.68 p.a. Cogs ), depreciation, and necessary operating expenses this double taxation grow or decrease, on. Errors or incorrect applications of generally accepted accounting principles Year stock History, AAPL. re important shareholders... White papers, government data, original reporting, and are associated following... Company ’ s balance sheet if the balance cons of retained earnings to have high or low retained earnings lies... Subtracted any impairment is considered as long-term source of finance it demonstrates a track record of profitability in years. December 2014 exam, it also seems they haven ’ t subtracted any impairment business may have its... The LLP could face dissolution methods one can use to keeping money and. At a later date takes in more money in revenue than it pays out retained! Resultant number may either be positive ( profits ) or negative ( losses ) member. ), depreciation, and necessary operating expenses earning ultimately settles as “ cash ” in the company to... By net losses … the retained earnings decrease when a company 's retained earnings eliminates fear. If new investments decisions are taken, the price appreciation should have been kept for in. There and hindering the company ’ s cracked up to be opposed to new shares or debentures avoids costs... 28.87 earnings per share grown at a later date of each accounting period ( quarterly/annually )! Cash dividend are generally issued from the retained earnings eliminates the fear of ownership dilution and loss of by! The end of each accounting period ( quarterly/annually. in business the standards of Warren Buffett the. It pays out its retained earnings balance the financial statements, particularly the balance sheet items relative to the 's... Figures are available under the “ Key ratio ” section of the balance.! Ratio is the measure of dividends paid, plus prior period adjustments producing accurate, content. The term refers to shareholders relative to the profits which have not been as!
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https://www.assignmentexpert.com/homework-answers/economics/macroeconomics/question-6251
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# Answer to Question #6251 in Macroeconomics for sam
Question #6251
In a closed economy the following holds:
Household consumption C is given by the consumption function:
C = 100 + 0.75Yd
Planned investments are I = 250 (independent of Y ).
Household disposable income: Yd = Y − T, where Y is production.
Taxes depend on income according to: T = −200 + 0.5Y .
Public consumption: G = 1000.
(a) Use the simple Keynesian model of the goods market to calculate equilibrium
production Y , i.e. the level of production compatible with planned
expenditure in the form of consumption and investments.
(b) What is the public budget deficit?
(c) Suppose that the government increases public consumption to G = 1100.
What is production in the new equilibrium?
(d) What is the public deficit after the increase of public consumption?
(e) What is the multiplier for an (unfinanced) increase in public consumption.
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http://mathematica.stackexchange.com/questions/5444/is-it-possible-to-get-the-order-of-inputs-when-overloading-an-orderless-functi
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# Is it possible to get the order of inputs when “overloading” an orderless function?
When working with symbolic matrix operations or other objects which don't have commutative multiplication, it would be nice to not have to constantly switch out times for NonCommutativeMultiply (**). So I was wondering if there is a way to do something like
matrix /: Times[pre___, a_matrix, post___] := NonCommutativeMultiply[pre, a, post]
a = matrix["a"];
b = matrix["b"];
and then have it replaced automatically. However since Times is orderless, this doesn't preserve the order. In general, is it impossible to get the order of inputs when doing this kind of "overloading" though upvalues of an orderless function?
-
Check out this answer to my question about block inversion. A package called NCAlgebra may help. – Eli Lansey May 11 '12 at 10:25
Well, you can sort of do this, by creating something like a continuation. This requires playing games with the Stack, and I don't claim that it is robust, but it may represent some theoretical interest, particularly to those of us looking for ways to implement continuations in Mathematica. Here is the code (edit please note that I had to add Update[matrix] to address some improper behavior noted in the comments end edit):
ClearAll[matrix, inMatrix];
matrix /: HoldPattern[Times[pre___, a_matrix, post___]] :=
(
Update[matrix];
ReleaseHold[NonCommutativeMultiply @@@ $stack] ); matrix[args__] /; ! TrueQ[inMatrix] := Block[{inMatrix = True}, Update[matrix];$stack = Stack[_][[-5]];
matrix[args]]
It combines UpValues, Villegas-Gayley trick to redefine a function, and manipuations with Stack. What happens is that first, of course, the attributes of Times are applied, I can't fight that. Then, the DownValues of matrix are applied, and at this point I record the relevant part of the Stack. Then, UpValues of matrix are applied, and at that point I communicate the recorded part of the stack, where the attributes of Times weren't yet applied, and Times gets replaced with NonCommutativeMultiply, after which I re-evaluate this, as if it was not evaluated before. The Update sommand is used to prevent caching the values for the $stack, as this is inappropriate here and resulted in some erroneous behavior noted in the comments. Here are some examples: a = matrix["a"]; b = matrix["b"]; a*c*b matrix[a]**c**matrix[b] f[g[1 + c*a*d*b*e]] f[g[1 + c ** matrix["a"] ** d ** matrix["b"] ** e]] I would not probably recommend such tricks for serious use, it is just interesting that you can use them to divert evaluation sequence in ways which seem to be impossible otherwise. - I tried to put something like this together and failed. Once again you prove your mastery. :-) – Mr.Wizard May 11 '12 at 21:14 @Mr.Wizard Well, thanks, but I am not really sure that actually using this code is a good idea. It may not be robust enough. I just like this direction of thought. – Leonid Shifrin May 11 '12 at 21:16 Really really cool. I never looked at Stack[] before, but was hoping something like this would be possible. Now comes the follow up question, how do you break it, or really when does this go horribly wrong? – jVincent May 11 '12 at 21:17 @jVincent I wasn't able to break this with a few tests, but I think it should be possible, and I did not try hard enough. For one thing, all code inside Times will be executed twice, and so if it contains side effects, those would also happen twice. But I think one can probably break this even more severely. For symbolic expressions, though, it may be ok. – Leonid Shifrin May 11 '12 at 21:24 @jVincent Yes you are right, but this is rather subtle. The value of the $stack was cached and not re-computed as it should've been. Fixed now - I added the Update statements in appropriate places. – Leonid Shifrin May 14 '12 at 7:02
As far as I know this cannot be made to work in the manner you show so long as the Orderless property of Times remains, because this property is applied before pattern rules are applied.
You can of course do things such as Blocking Times but I cannot think of a way to get (automatically) the behavior you desire without bad side effects.
-
there is a package called NCAlgebra I used some time ago to handle non-commutative variables (not just in matrix representation but also quaternions etc) in a multitude of situations.
http://www.math.ucsd.edu/~ncalg/
I think it would solve your problem as it defines its own substitution and expansion rules. You get the option to define a variable as non-commutative and then "do stuff" to it. In your example, and using this package
SetNonCommutative[A, B]
would define A, B to be treated as non-commutative symbols and the order in multiplication will be preserved.
-
Looking thought the example notebooks from this package, it appears that they just use NonCommutativeMultiply exclusively, and provide an external framework for doing other manipulations. – jVincent May 11 '12 at 10:45
Yes, this is correct. But Mathematica cannot handle expansions in NonCommutativeMultiply and you'd need to type long expressions with **s yourself. I thought that's what triggered the question in the first place (?) – gpap May 11 '12 at 10:51
No, what triggered my question is just the annoyance at the fact that Times being defined as orderless in general makes it seamingly impossible to make it non orderless in individual cases based no the elements. Mathematically the communicative nature of multiplication is dependent on the elements, not the operator, I was hoping for some clever fix that didn't involve hunting down every single occurance of times, and replacing it, or blocking it out in order to retain order information. – jVincent May 11 '12 at 10:56
I see - in that case my answer is useless. So, in your example above, if you wanted multiplication over Z4 you would define a z4 "times" that would give you z4[a] z4[b]=Mod[a,b,4] but in your case wouldn't that transpose the problem into defining all your elements of z4 in an expression? – gpap May 11 '12 at 11:27
Naturally, but lets assume you have a large collection of functions that do things like f[a_,b_]:=a+b-b^2-b*a, or similar. Suddenly all of these expression would obay the nocommutativity of the newly defined matrix objects, if you called f[matrix[a],matrix[b]]. Really what I want is to have the evaluation depending on the upvalues of the members, but that's not possible, since Times is orderless independent of what it's used on. – jVincent May 11 '12 at 12:38
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http://mathhelpforum.com/pre-calculus/199696-help-wih-parametric-representation-function-print.html
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Help wih parametric representation of a function
• Jun 5th 2012, 11:20 PM
Rascot
Help wih parametric representation of a function
Hi, I'm stuck trying to obtain the cartesian equation of the function defined parametrically by x=1/2(t+1/t), y=1/2(t-1/t).
The book (Mathematics for Engineers, Croft / Davison) gives x^2 - y^2 = 1 as the answer, but I can't figure out how they got there. Ideas?
• Jun 5th 2012, 11:44 PM
earboth
Re: Help wih parametric representation of a function
Quote:
Originally Posted by Rascot
Hi, I'm stuck trying to obtain the cartesian equation of the function defined parametrically by x=1/2(t+1/t), y=1/2(t-1/t).
The book (Mathematics for Engineers, Croft / Davison) gives x^2 - y^2 = 1 as the answer, but I can't figure out how they got there. Ideas?
1. Rearrange both equations to:
$2x = t +\frac1t~\wedge~2y=t-\frac1t$
2. Add both sides of the equations:
$2x+2y = 2t~\implies~t = x+y$
3. Replace t in the 1st equation by (x+y):
$x = \frac12 \cdot \left((x+y)+\frac1{x+y} \right)$
4. Expand the brackets and after a few steps of rearranging you'll get the given result.
• Jun 6th 2012, 12:05 AM
Rascot
Re: Help wih parametric representation of a function
Perfect! Completely forgot about solving simultaneous equations (probably because they are dealt with later in the book). You have my thanks, sir.
By the way, how do you (and pretty much everyone on this forum) post math symbols as images? Is there a piece of software you guys use?
• Jun 6th 2012, 12:26 AM
earboth
Re: Help wih parametric representation of a function
Quote:
Originally Posted by Rascot
Perfect! Completely forgot about solving simultaneous equations (probably because they are dealt with later in the book). You have my thanks, sir.
By the way, how do you (and pretty much everyone on this forum) post math symbols as images? Is there a piece of software you guys use?
1. Go to LaTeX Help Forum. You'll find 2 tutorials where you can find how to use the implemented Latex-compiler.
2. If you need the synatx of a Latex command you'll find it probably here: Help:Displaying a formula - Wikipedia, the free encyclopedia
• Jun 6th 2012, 06:30 AM
Soroban
Re: Help wih parametric representation of a function
Hello, Rascot!
Quote:
Hi, I'm stuck trying to obtain the cartesian equation of the function
. . defined parametrically by: . $\begin{Bmatrix}x &=& \frac{1}{2}(t+\frac{1}{t}) \\ \\[-3mm] y&=& \frac{1}{2}(t-\frac{1}{t}) \end{Bmatrix}$
The book (Mathematics for Engineers, Croft/Davison) gives $x^2 - y^2 \,=\, 1$ as the answer.
Square the equations: . $\begin{Bmatrix}x^2 &=& \frac{t^2}{4} + \frac{1}{2} + \frac{1}{4t^2} & [1] \\ \\[-4mm] y^2 &=& \frac{t^2}{4} - \frac{1}{2} + \frac{1}{4t^2} & [2] \end{Bmatrix}$
Subtract [2] from [1]: . . $x^2 - y^2 \;=\;1$
• Jun 6th 2012, 12:59 PM
Rascot
Re: Help wih parametric representation of a function
Thank you both very much for your help. I can't mark the thread as solved, but would kindly ask moderators to do so if they happen to come across it.
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http://www.jzus.zju.edu.cn/article.php?doi=10.1631/jzus.A1200321
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Full Text: <4066>
CLC number: U270.1+1
On-line Access: 2013-06-03
Revision Accepted: 2013-04-29
Crosschecked: 2013-05-16
Cited: 6
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Journal of Zhejiang University SCIENCE A 2013 Vol.14 No.6 P.447-458 10.1631/jzus.A1200321
Dynamic analysis of a high-speed train operating on a curved track with failed fasteners*
Author(s): Li Zhou, Zhi-yun Shen Affiliation(s): . State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, China Corresponding email(s): [email protected] Key Words: High-speed train, Ballast track, Failed fastener, Wheel/Rail force, Derailment coefficient, Wheelset loading reduction Share this article to： More <<< Previous Article|
Li Zhou, Zhi-yun Shen. Dynamic analysis of a high-speed train operating on a curved track with failed fasteners[J]. Journal of Zhejiang University Science A, 2013, 14(6): 447-458.
@article{title="Dynamic analysis of a high-speed train operating on a curved track with failed fasteners",
author="Li Zhou, Zhi-yun Shen",
journal="Journal of Zhejiang University Science A",
volume="14",
number="6",
pages="447-458",
year="2013",
publisher="Zhejiang University Press & Springer",
doi="10.1631/jzus.A1200321"
}
%0 Journal Article
%T Dynamic analysis of a high-speed train operating on a curved track with failed fasteners
%A Li Zhou
%A Zhi-yun Shen
%J Journal of Zhejiang University SCIENCE A
%V 14
%N 6
%P 447-458
%@ 1673-565X
%D 2013
%I Zhejiang University Press & Springer
%DOI 10.1631/jzus.A1200321
TY - JOUR
T1 - Dynamic analysis of a high-speed train operating on a curved track with failed fasteners
A1 - Li Zhou
A1 - Zhi-yun Shen
J0 - Journal of Zhejiang University Science A
VL - 14
IS - 6
SP - 447
EP - 458
%@ 1673-565X
Y1 - 2013
PB - Zhejiang University Press & Springer
ER -
DOI - 10.1631/jzus.A1200321
Abstract:
A high-speed train-track coupling dynamic model is used to investigate the dynamic behavior of a high-speed train operating on a curved track with failed fasteners. The model considers a high-speed train consisting of eight vehicles coupled with a ballasted track. The vehicle is modeled as a multi-body system, and the rail is modeled with a Timoshenko beam resting on the discrete sleepers. The vehicle model considers the effect of the end connections of the neighboring vehicles on the dynamic behavior. The track model takes into account the lateral, vertical, and torsional deformations of the rails and the effect of the discrete sleeper support on the coupling dynamics of the vehicles and the track. The sleepers are assumed to move backward at a constant speed to simulate the vehicle running along the track at the same speed. The train model couples with the track model by using a Hertzian contact model for the wheel/rail normal force calculation, and the nonlinear creep theory by Shen et al. (1984) is used for wheel/rail tangent force calculation. In the analysis, a curved track of 7000-m radius with failed fasteners is selected, and the effects of train operational speed and the number of failed fasteners on the dynamic behaviors of the train and the track are investigated in detail. Furthermore, the wheel/Rail forces and derailment coefficient and the wheelset loading reduction are analyzed when the high-speed train passes over the curved track with the different number of continuously failed fasteners at different operational speeds. Through the detailed numerical analysis, it is found that the high-speed train can operate normally on the curved track of 7000-m radius at the speeds of 200 km/h to 350 km/h.
## 1. Introduction
Railway track support failure quite often takes place in service due to the non-uniform roadbed settlement and the fierce wheel/rail vibration at high frequencies, which may originate from non-homogeneities in the ballast and substrate or from out of the roundness of wheels and rail corrugation. Railway track support failure mainly includes the fastener fracture, sleeper fracture or sleeper suspension, slab fracture, ballasted bed collapse, etc. Augustin et al. () found, in their experimental study on the settlement of a ballasted track, that up to 50% of all sleepers are more or less hanging. The track support failure results in railroad accidents of derailment. On Dec. 21, 1993, an unsupported track section (Fig. 1), caused a derailment of an SNCF TGV train at the Haute Picardie, France (Brabie, ). On Aug. 9, 1997, an Amtrak Southwest Chief train derailed on the east bound track near Kingman, Arizona, USA when crossing an unsupported bridge section (National Transportation Safety Board, ). On June 26, 1999, a Canadian Pacific Railway eastward train derailed due to a roadbed depression at Mile 5.3 of the Keewatin Subdivision near Keewatin, Ontario (Transportation Safety Board of Canada, ). However, so far very few studies on vehicle derailment have taken track support failure into account.
Fig.1
Unsupported track section (Brabie, )
Since the early 1970s, many theoretical models have been developed to predict the behavior of railway vehicle and track systems (Knothe and Grassie, ; Popp et al., ). Generally, in the existing models the vehicle is modeled as a multiple rigid body system, and the rails are represented by the Euler or Timoshenko beams resting on the Winkler elastic foundation or discrete sleepers. The continuous support track models provide only a limited insight into the dynamic response of various simplified components of the track, while the discrete models or the finite element models can achieve an improved prediction of all the conceivable track components including rails, sleepers, slabs and even the ballast.
The coupled vehicle/track models can characterize many basic phenomena, and they are widely used to understand the behavior of the railway system dynamics. Among the existing dynamic models of railway vehicle coupled with a track, most were used to deal with vehicle/track vertical interaction problems in relatively low frequency ranges (Nielsen and Igeland, ; Ripke and Knothe, ; Frohling, ; Oscarsson and Dahlberg, ; Sun and Dhanasekar, ; Lei and Mao, ; Cai et al., ), and a few were used to analyze the lateral and vertical dynamics (Zhai et al., ; Jin et al., ; Xu and Ding, ; Baeza and Ouyang, ; Xiao et al., ). Although the coupled vehicle/track models can solve many scientific problems effectively, there are some issues that these models cannot deal with. The most prominent one is that they cannot consider the effect of the inter-vehicle connections on the dynamic behavior of the train/track system. Most modern high-speed trains are equipped with the tight-lock inter-vehicle connections, such as the tight-lock couplers and an inter-vehicle damper. When high-speed trains operate in complex operating environments, such as derailment occurring due to stronger cross-wind blowing or earthquake or serious track bulking, the mutual influence between the adjacent vehicles on the system dynamic behavior should not be neglected in the dynamic behavior analysis (Evans and Berg, ; Zhang, ). In these environments no single-vehicle/track model cannot characterize the behavior of the vehicle and track accurately or reliably.
In addition, many vehicle-bridge interaction and train-track-bridge coupling models were developed to investigate the railway system dynamics. In these studies, the train was usually modeled as a series of moving loads or an improved multi-rigid-body system. When dealing with the bridge structure, two kinds of numerical methods were widely used. One is the finite element method (FEM), and the other is the component mode synthesis method (substructure approach). Owing to its high accuracy and versatility, the FEM is extensively used to investigate the dynamic response of a bridge structure under moving vehicles (Frýba, ; Yang and Wu, ; Xia and Zhang, ; Ju and Lin, ; Lou, ), but its limitation is very time-consuming due to the large number of degrees of freedom. A lot of recent researches used the substructure approach rather than the FEM to deal with the dynamic analysis of train-track-bridge systems subjected to moving trains (Cheung et al., ; Biondi and Muscolino, ; Biondi et al., ; Lou, ; de Salvo et al., ). In these models, the bridge has been modeled as a beam-like structure, which is similar to the modeling rails in vehicle/track interaction. The main advantage of such a simplified model is that it allows using analytical methods for analyzing bridge vibrations.
Most of the dynamic models developed in the above studies consider only a single vehicle coupled with the track or bridge, which ignores the influence of inter-vehicle connections on the dynamics of trains. While some of them consider multiple vehicles, the inter-vehicle connection model was still neglected. Furthermore, almost all the existing dynamic models considering multiple vehicles are based on the assumption that the track is regarded as a rigid track or a nearly rigid track. These models cannot take the track support stiffness variation along the track into account. In the present paper, a 3D-coupled train/track dynamic model, considering the various discrete supports by sleepers and track support stiffness, is introduced to analyze the effect of train speed and broken fasteners on a curved track on the dynamic behavior of the train and the track when the high-speed train passes over the curved track with the failed fasteners at different speeds. The proposed model considers an eight-vehicle train coupled with a three-layer ballasted track. In the model, each vehicle is modeled as a multi-body system, and rails are assumed to be Timoshenko beams supported by the discrete sleepers. The vehicle model considers the effect of the inter-vehicle connections on the dynamic behavior of the neighboring vehicles. The rail supports are assumed to move backward at a constant speed to simulate the vehicle running forward along the track at the same speed. The dynamic behavior analysis includes the wheel/rail forces and the derailment coefficients consisting of L/V and ∆V/V. L/V indicates the ratio of the lateral force to the vertical force of the wheel/rail, and ∆V/V is the wheel load reduction. The time-dependent L/V and ∆V/V are used to assess the risk of derailment. They are useful to directly evaluate and control the dynamic derailment of a high-speed train operating the curved track with failed fasteners. This investigation helps to better understand the vehicle derailment mechanism due to a track fastener failure.
## 2. Model of vehicle/track
### 2.1. Vehicle model
A 3D dynamic model of a high-speed train composed of multiple vehicles coupled with a ballast track is shown in Fig. 2. The coupled train/track dynamic model consists of four subsystems: the vehicle, the inter-vehicle connection, the track, and the wheel/rail contact. Each vehicle considered is equipped with a pair of two-axle bogies with double suspension systems. The wheelset and the bogie are connected by the primary suspension, while the car body is supported on the bogie through the secondary suspension. Each component of the vehicle has six degrees of freedom: the longitudinal displacement X, the lateral displacement Y, the vertical displacement Z, the rolling angle ϕ, the pitching angle β, and the yawing angle ψ. 3D spring-damper elements are used to represent the primary and the secondary suspensions, and the nonlinear dynamic characteristics of the suspension systems are considered, including the nonlinear yaw dampers, the nonlinear lateral dampers, and the nonlinear stoppers installed on the secondary suspension as well as the nonlinear vertical dampers installed on the primary suspension (Xiao et al., ). A detailed inter-vehicle connection model is established. The nonlinear coupler-draft gear system and nonlinear inter-vehicle dampers are replaced with unidirectional nonlinear spring-damper elements. The tight-lock vestibule diaphragm is simplified as the 3D spring element, which restrains the adjacent vehicles in the longitudinal, lateral, vertical, rolling, pitching, and yawing directions. The inter-vehicle forces can be calculated based on the deformation of the connectors and the relative angle between the connectors and the car bodies (Ling, ).
Fig.2
High-speed train/track coupling model
Since the vehicle system contains many differential equations and the detailed derivation of the equations is tedious (which is ignored here), the equations of motion are expressed as $${{\mathbf{M}}_v}{{\mathbf{\ddot X}}_v} + {{\mathbf{C}}_v}{{\mathbf{\dot X}}_v} + {{\mathbf{K}}_v}{{\mathbf{X}}_v} = {{\mathbf{F}}_{wr}} + {{\mathbf{F}}_{ext}} + {{\mathbf{F}}_{iv}}$$, where M v, C v, and K v are the mass, damping, and stiffness matrices of the vehicle subsystem, respectively; $${{\mathbf{\ddot X}}_v}$$, $${{\mathbf{\dot X}}_v}$$, and X v are the acceleration, velocity, and displacement vectors of the vehicle subsystem, respectively; F wr is the vector of the nonlinear wheel-rail contact forces determined by the wheel-rail contact model; F ext is the vector of external forces including gravitational forces and forces resulting from the centripetal acceleration when the vehicle negotiating the curved track; and F iv is the vector of the nonlinear inter-vehicle contact forces due to the couplers, inter-vehicle dampers, and the tight-lock vestibule diaphragm. The equation derivations of the vehicle system and the inter-vehicle connection model, which can be seen in (Ling, ), are omitted here.
### 2.2. Track model
The model of the track is a three-layer model consisting of rails, sleepers, and ballast bed (Fig. 2). In the track model, the rails are assumed to be Timoshenko beams supported by discrete sleepers, and the effects of the vertical and lateral motions and rolling of rails on the wheel/rail creepages are taken into account. Each sleeper is treated as an Euler beam supported by uniformly distributed stiffness and damping in its vertical direction, and a lumped mass is used to replace the sleeper in its lateral direction. The ballast bed is replaced by equivalent rigid ballast bodies in the calculation model, with only the vertical motion of each ballast body taken into account. The motion of the road bed is neglected. The equivalent springs and dampers are used as the connections between rails and sleepers, between sleepers and ballast blocks, and between ballast blocks and roadbed.
The deformation of rails is described by the Timoshenko beam theory, including the bending and torsion. Using the modal synthesis method and normalized shape functions of the Timoshenko beam, the fourth-order partial differential equations of rails are converted into second-order ordinary equations as follows:
for the lateral bending motion: ${\kern 0pt} \left\{ \begin{matrix} {{\ddot q}_{yk}}(t) + \frac{{{\kappa _y}GA}}{{\rho A}}{\left( {\frac{{k\pi }}{{{l_{tim}}}}} \right)^2}{q_{yk}}(t) - {\kappa _y}GA\frac{{k\pi }}{{{l_{tim}}}}\sqrt {\frac{1}{{\rho A\rho {I_z}}}} {w_{yk}}(t) = - \sum\limits_{i = 1}^{{N_s}} {{R_{yi}}(t){Y_k}({x_{si}})} + \sum\limits_{j = 1}^{{N_w}} {{F_{wryj}}(t){Y_k}({x_{wj}}),} \hfill \\ \;{{\ddot w}_{yk}}(t) + \left[ {\frac{{{\kappa _y}GA}}{{\rho {I_z}}} + \frac{{E{I_z}}}{{\rho {I_z}}}{{\left( {\frac{{k\pi }}{{{l_{tim}}}}} \right)}^2}} \right]{w_{yk}}(t)\; - {\kappa _y}GA\frac{{k\pi }}{{{l_{tim}}}}\sqrt {\frac{1}{{\rho A\rho {I_z}}}} {q_{yk}}(t) = 0,\;\;k = 1,2,...,{\text{NMY,}} \hfill \\ \end{matrix} \right.$
for the vertical bending motion, ${\kern 0pt} \left\{ \begin{matrix} {{\ddot q}_{zk}}(t) + \frac{{{\kappa _z}GA}}{{\rho A}}{\left( {\frac{{k\pi }}{{{l_{tim}}}}} \right)^2}{q_{zk}}(t) - {\kappa _z}GA\frac{{k\pi }}{{{l_{tim}}}}\sqrt {\frac{1}{{\rho A\rho {I_y}}}} {w_{zk}}(t) = - \sum\limits_{i = 1}^{{N_s}} {{R_{zi}}(t){Z_k}({x_{si}})} + \sum\limits_{j = 1}^{{N_w}} {{F_{wrzj}}(t){Z_k}({x_{wj}}),} \hfill \\ {{\ddot w}_{zk}}(t) + \left[ {\frac{{{\kappa _z}GA}}{{\rho {I_y}}} + \frac{{E{I_y}}}{{\rho {I_y}}}{{\left( {\frac{{k\pi }}{{{l_{tim}}}}} \right)}^2}} \right]{w_{zk}}(t) - {\kappa _z}GA\frac{{k\pi }}{{{l_{tim}}}}\sqrt {\frac{1}{{\rho A\rho {I_y}}}} {q_{zk}}(t) = 0,\;\;k = 1,2,...,{\text{NMZ,}} \hfill \\ \end{matrix} \right.$
and for the torsional motion, $${\ddot q_{Tk}}(t) + \frac{{GK}}{{\rho {I_{\text{0}}}}}{\left( {\frac{{k\pi }}{{{l_{tim}}}}} \right)^2}{q_{Tk}}(t) = - \sum\limits_{i = 1}^{{N_s}} {{M_{si}}(t){\Phi _k}({x_{si}})} + \sum\limits_{j = 1}^{{N_w}} {{M_{Gj}}(t){\Phi _k}({x_{wj}}),} \;k = 1,2,...,{\text{NMT}}$$.
In Eqs. (2)–(4), qyk (t), qzk (t) and qTk (t) are the generalized coordinates of the lateral, vertical, and rotational deflections of the rail, respectively; while wyk (t) and wzk (t) are the generalized coordinates of the deflection curve of the rail with respect to the z-axis and y-axis. The material properties of the rail are indicated by the density ρ, the shear modulus G, and Young’s modulus E. The geometry of the cross section of the rail is represented by the area A, the second moments of area Iy and Iz around the y-axis and z-axis, respectively, and the polar moment of inertia I 0. The shear coefficients κy =0.4057 and κz =0.5329 for the lateral and vertical bendings, respectively, and the shear coefficient K=2.473346×10−6 are obtained through a finite element analysis of the rail profile of China CN 60 using the software package ANSYS. The calculation length of the beam is denoted by l tim. Ryi and Rzi are, respectively, the lateral and vertical forces between the rail and the sleeper i. The wheel/rail forces at the wheel j in the lateral and vertical directions are represented by F wryj and F wrzj . M si and M Gj denote the equivalent moments acting on the rail. Yk (x), Zk (x), and Φk (x) are the kth shape function, and NMY, NMZ, and NMT are the total number of shape functions. x si and x wj denote the longitudinal positions of the sleeper i and the wheel j, and N w and N s are the numbers of the wheelsets and the sleepers within the analyzed rail, respectively. The subscript i indicates the sleeper i, and j is for the wheel j, respectively.
The sleeper in the present model is treated as an Euler-Bernoulli beam with free-free ends in the vertical direction, while as a lumped mass for its lateral motion (Fig. 2). Using the modal synthesis method and the normalized shape functions of the Euler beam, the fourth-order partial differential equations of the sleeper vertical vibration can be simplified as a second-order ordinary equation as follows: $${\ddot q_{sk}}(t) + \frac{{{E_s}{I_s}}}{{{m_s}}}{\left( {\frac{{k\pi }}{{{l_s}}}} \right)^4}{q_{sk}}(t) = - \sum\limits_{i = 1}^{{N_b}} {{F_{bzi}}(t){Z_{sk}}({y_{bi}})} + \sum\limits_{j = 1}^{{N_r}} {{R_{zRj}}(t){Z_{sk}}({y_{rj}}),} {\text{ }}k = 1,2,...,{\text{NMS}}$$, where q sk (t) is the generalized coordinates of the sleeper vertical deflection, E s is Young’s modulus, I s is the second moment of area of the rail cross-section about y axis, m s is the mass per unit longitudinal length, and l s is the length of the sleeper. F bzi is the force between the sleeper and ballast body in the action point i, and Rz Rj is the force between the sleeper and the rail in the action point j. Z sk (y) is the kth modal function, and NMS is the total number of shape functions.
According to Newton’s Second Law, the lateral rigid motion of the sleeper can be written as $${M_s}{\ddot Y_{si}} = ({F_{yLi}} + {F_{yRi}}) - {F_{byi}}$$, where Fy Li and Fy Ri are the lateral forces between sleeper i and the left and right rails, respectively, and F byi is the equivalent lateral support force by the ballast body. The subscripts L and R denote, respectively, the left and right rails (wheels). The longitudinal rigid motion and rotating motions of each sleeper are neglected.
The ballast bed is replaced by equivalent rigid ballast bodies in this calculation model, and only the vertical motion of each ballast body is taken into account. The vertical motion equations of ballast bodies i are: $${M_b}{\ddot Z_{bLi}} = {F_{bzLi}} + {F_{zrLi}} + {F_{zLRi}} - {F_{zgLi}} - {F_{zfLi}} + {M_b}g$$, $${M_b}{\ddot Z_{bRi}} = {F_{bzRi}} + {F_{zrRi}} - {F_{zLRi}} - {F_{zgRi}} - {F_{zfRi}} + {M_b}g$$, where Fz fLi , Fz rLi , Fz fRi , Fz rRi , and Fz LRi are the vertical shear forces between the neighboring ballast bodies, and Fz gLi and Fz gRi are the vertical forces between the ballast bodies and the roadbed. M bL and M bR are the masses of the left and right ballast body, and g is the gravity acceleration. This ballast model can represent the in-phase and out-of-phase motions of two vertical rigid modes in the vertical-lateral plane of the track. For brevity, the detailed derivation of track system equations, which can be seen in (Xiao et al., ), is omitted.
### 2.3. Model of wheel/rail interaction
The calculation of wheel/rail contact forces includes a normal model and a tangent model. The normal model, which characterizes the relationship law of the normal load and deformation between the wheel and rail, is described by a Hertzian nonlinear contact spring with a unilateral restraint: $$N(t) = \left\{ {\begin{array}{*{20}{c}} {{{\left[ {\frac{1}{{{G_{Hertz}}}}{Z_{wrnc}}(t)} \right]}^{3/2}},{Z_{wrnc}}(t) \textgreater 0,} \\ {0,\;\;\;{Z_{wrnc}}(t) \leqslant 0,} \end{array}} \right.$$, where G Hertz is the wheel/rail contact constant (m/N2/3), which can be obtained using the Hertz contact theory (Jin et al., ). Z wrnc(t) is the normal compressing amount at wheel/rail contact point. Z wrnc(t) is strictly defined as an approach between the two distant points, the one belonging to the wheel, and the other one belonging to the rail. The wheel and the rail are assumed to be an elastic half-space. This approach is confined to the normal direction at the contact point of the wheel and the rail. Z wrnc(t)>0 indicates the wheel/rail in contact, and Z wrnc(t)≤0 indicates their separation.
The model developed by Shen et al. () is used as the tangent model determining the relationship between the creepages and the total creep forces of the wheel/rail. In the tangent force calculation, firstly, wheel/rail creep forces are calculated according to the Kalker linear creep theory (Kalker, ), and then amended using the model of Shen-Hedrick-Elkins. The Kalker linear creep theory is only available for small creepages. With large creepages, for example, in the case of wheel/rail flange contact, the creep forces enter saturation, and then creep forces non-linearly vary with the creepages.
### 2.4. Evaluation criteria of railway vehicle derailment
At present two important criteria are widely used to evaluate the dynamic behavior and safety operation of high-speed trains. One is the Nadal’s criterion, denoted by Eq. (10), and the other is the wheelset loading reduction indicated by Eq. (11): ${\left( {\frac{L}{V}} \right)_{Critical}} = \frac{{\tan {\delta _{max}} - \mu }}{{1 + \mu \tan {\delta _{max}}}}$, $$\frac{{\Delta V}}{V} = \frac{{\frac{1}{2}({V_L} - {V_R})}}{{\frac{1}{2}({V_L} + {V_R})}} = \frac{{{V_L} - {V_R}}}{{{V_L} + {V_R}}}$$, where δ max is the maximum flange angle of wheel, μ indicates the coefficient of friction between the wheel and the rail. L and V denotes, respectively, the lateral and vertical forces of the wheel and the rail, and ΔV indicates the normal loading difference of the left and right wheels of the same wheelset.
## 3. Numerical results and discussion
### 3.1. Dynamic behavior analysis of a high-speed train passing over a curved track with failed fasteners
In the analysis, the considered curved track has a radius of 7000 m and the super-elevation of 150 mm. It is assumed that five failed fasteners occur, respectively, on the low rail, the high rail, and both the rails of the circle section of the curved track. The usual track geometry irregularity is not considered. The train speed is 350 km/h. The rail fastener failure is simulated by changing the stiffness and damping coefficients of the fasteners and rail pads, and the parameter variations considered in the coupled train/track model are as follows: ${\kern 0pt} \left\{ \begin{matrix} {K_{flLi}} = {K_{flRi}} = {C_{flLi}} = {C_{flRi}} = 0, \hfill \\ {K_{pvLi}},{C_{pvLi}} = {K_{pvRi}},{C_{pvRi}} = {K_{pv0}},{C_{pv0}},{\text{ }}{z_{rL(R)i}} \textgreater {z_{spL(R)i}}{\text{,}} \hfill \\ {K_{pvLi}},{C_{pvLi}} = {K_{pvRi}},{C_{pvRi}} = 0,{\text{ }}{z_{rL(R)i}} \leqslant {z_{spL(R)i}}{\text{, }} \hfill \\ \end{matrix} \right.$ where K flL(R)i and C flL(R)i stand for the lateral stiffness and damping coefficient of the fastener i, K pvL(R)i and C pvL(R)i denote the vertical stiffness and damping coefficient of the rail pad i, z rL(R)i and z spL(R)i indicate the vertical displacements of rails and sleepers in the action point i, respectively.
Fig. 3 illustrates the lateral and vertical forces between the rails and the first wheelset of the first vehicle when the high-speed train passes over the curved track with the different distribution of the failed fasteners at 350 km/h. “Failed fasteners” in Fig. 3 indicates the location of the five failed fasteners. It is noted that the small black boxes in the figures indicate a normal track fasteners, and the white ones correspond to the failed rail fasteners. When the high-speed train passes through the fastener failure section, the considerable impact vibrations occur between the wheels and the rails, and then they gradually decay and get into steady-state, which is similar to the track without the failure rail fasteners. Form Fig. 3, it is obvious that the forces of the wheel/rail fluctuate dramatically in the case where the fastener failure occurs on the curved track. When the first vehicle passes through the track section with five failure fasteners, the maximum lateral and vertical forces are generated on the left wheel of wheelset 1, and the minimum interaction forces are generated on the right wheel. Owing to the impact of the disabled fasteners and the external centrifugal inertial forces of the vehicle bodies when the train is negotiating the curved track, the lateral and vertical forces on the left wheel (on the high rail) are much larger than those on the right wheel of the same wheelset. In this situation, the right wheel easily jumps and loses contact with the low rail, and the high-speed train risks a jumping derailment if there is a moderate lateral impact load applied on the vehicle system, such as a cross-wind applied to the right side of the train.
Fig.3
Wheel/Rail forces in different cases of five failed fasteners
(a) Lateral forces on high rail; (b) Lateral forces on low rail; (c) Vertical forces on high rail; (d) Vertical forces on low rail
Compared to the normal condition, the maximum lateral force on the high rail increases by about 10%, 83%, and 113% in the cases, respectively, where the fastener failure occurs on the low rail, high rail, and both high and low rails of the curved track. Meanwhile, the minimum lateral force on the low rail decreases by about 66%, 92%, and 125%, respectively, as indicated in Figs. 3a and 3b. With regard to the wheel/rail vertical force, the maximum vertical force on the high rail increases by about 0.95%, 12.6%, and 13%, respectively, and the minimum vertical force on the low rail decreases by about 1%, 7%, and 8.3%, respectively (Figs. 3c and 3d). These results demonstrate that failed fasteners will lead to a large variation in the lateral wheel/rail forces, which would seriously threaten the running safety of a high-speed train. In addition, the influence of the limited fastener failure on the low rail is relatively small on the wheel/rail forces, compared to the fastener failure occurring on the high rail of the curved track.
Figs. 4 and 5 indicate the derailment coefficients (L/V) and the wheelset loading reductions (ΔV/V), respectively. The variation tendencies of L/V and ΔV/V are similar to the law curves in Fig. 3 when the high-speed train negotiates the curved track with failed rail fasteners. Compared to the case without a disabled rail fastener, the maximum derailment coefficient increases by about 10%, 100%, and 136% on the high rail and decreases by about 62%, 89%, and 123% on the low rail in the respective cases where the fastener failure occurs on the low rail, high rail, and both high and low rails of the curved track, as indicated in Figs. 4a and 4b. The maximum wheelset loading reduction increases by about 6%, 47%, and 44%, respectively, as shown in Fig. 5. Although the change rates of L/V and ΔV/V are large, the derailment coefficients and the wheelset loading reduction do not exceed their limit values in the three cases of fastener failure. The limit values of L/V and ΔV/V are 0.8 (Zhang, ) according to the standard of the Chinese high-speed railway.
Fig.4
Derailment coefficient (L/V) in the different cases of five failed fasteners
(a) High rail; (b) Low rail
Fig.5
Wheelset loading reduction ((V/V) in the different cases of five failed fasteners
Note that the maximum wheelset loading reduction in the case of five disabled fasteners occurring on the high rail is larger than that occurring on both high and low rails. Furthermore, the difference of wheelset loading reduction between the normal case and the case of five disabled fasteners occurring on the low rail is very minor. This phenomenon is much concerned with the high-speed train negotiating a curved track with the deficient super-elevation. In the present analysis case where the train speed is 350 km/h and the radius of the curved track is 7000 m, the super-elevation of 150 mm is truly undersized. In this situation, the wheel loading of the wheelsets are not symmetrical, and this asymmetrical load condition results in a train dynamic response being much related to the contact behaviour of the high rail and left wheels. When the high-speed train negotiates the curved track with disabled fasteners occurring on the high rail, the asymmetrical rail support state worsens the interaction of the wheel and the high rail.
### 3.2. Effect of train speed and failed fastener number
In the practical operation of high-speed trains, the operation speed always changes and the number of failed fasteners on the track is stochastic. The present model is used to calculate the combined effect of the train speed and the failed fastener number on the wheel/rail forces, L/V, and ΔV/V in order to help to maintain the high-speed track efficiently. In the calculation, it is assumed that the symmetrical failure of the fasteners on the curved track occurs. The other conditions are the same as shown in Section 3.1.
Fig. 6 indicates the effect of the failed fastener number on the maximum values of the wheel/rail forces, L/V, and ΔV/V of all the wheelsets at different speeds, where the horizontal solid lines denote their limit values. The limit value of the lateral wheel/rail forces is (10+P 0/3) kN and the limit value of the vertical forces is 170 kN (Zhang, ), where P 0 is the static load of wheelset. For each speed, the limited maximum number of the failed fasteners is determined by the minimum number of the failed fasteners in Figs. 6a–6d, namely, the smallest lateral coordinate corresponding to the intersection points of the horizontal solid lines and the corresponding curves indicating safety limit value in Fig. 6. For 200 km/h, the limited maximum number of the failed fasteners is 17, for 250 km/h it is 27, for 300 km/h it exceeds 32, and for 350 km/h, it is 18. Fig. 6a shows that the lateral force and its rate of increase with the number of fastener failures are the maximal at 200 km/h and the least at 300 km/h. The lateral force and its rate of increase at 350 km/h are the second largest. Fig. 6b shows that the situation is similar to Fig. 6a. This phenomenon is concerned with the 7000-m radius curved track with the super-elevation of 150 mm and the operation speed. When the train operation speed is 200 km/h, the super-elevation of 150 mm is oversize, and when the train speed is 350 km/h, it is undersize.
Fig.6
Safety criteria vs. train speed and fastener failure number
(a) Maximum wheel/rail lateral force; (b) Maximum wheel/rail vertical force; (c) Maximum derailment coefficient; (d) Maximum wheelset loading reduction
Fig. 6c indicates that the derailment coefficient at 350 km/h is the maximal with an increase in the failed fastener number and those at 200 km/h and 250 km/h are very close. Fig. 6d illustrates that the wheelset loading reduction at 200 km/h is the maximal with an increase in the failed fastener number and those at 250 km/h and 300 km/h are very close when the number of the failed fasteners is smaller than 24. When the number of the failed fasteners exceeds 24, the wheel on the high rail comes off the rail at 200 km/h (Fig. 6d). Thus, from Fig. 6, it is known that the limited maximum numbers of the failed fasteners are different when the high-speed train passes over the curved track with the failed fasteners at different speeds. The limited maximum number of the failed fasteners changes nonlinearly with the increase of the speed.
Fig. 6 also shows that the permissible maximum numbers of the failed fasteners, determined by the limit values of the wheel/rail lateral and vertical forces, L/V, and ΔV/V, are 17, 23, 19, and 22 in the four cases of different speeds. It can be found that the disabled fasteners occurring on the high-speed curved tracks lead to the large lateral forces between the wheels and the rails. The lateral wheel/rail force and the criteria L/V reach their limit values first. These results indicate that the lateral wheel/rail force and derailment coefficient should be considered as two important criteria when disabled rail fasteners are detected in the high-speed track maintenance.
### 3.3. Effect of vehicle location and failed fastener number
When a train passes over a curved track the dynamic behaviours of different vehicles of the same train are different. This section investigates the effect of the vehicle location and the failed fastener number on the derailment coefficient and the wheelset loading reduction of all the vehicles of the same train. Fig. 7a illustrates the maximum derailment coefficient of each vehicle when the train passes over the curved track with different numbers of failed fasteners at 350 km/h. Fig. 7b indicates the maximum wheelset loading reduction of each vehicle when the train passes over the track section with failed fasteners at 200 km/h. From Fig. 7a, the derailment coefficient of the first vehicle of the train is the maximal, and the second vehicle is the second largest. Those of other vehicles are very close. In contrast, the loading reduction of the last vehicle is the maximal, while the first vehicle is the least, as shown in Fig. 7b. From different variations of L/V and ΔV/V, the climbing derailment of the first vehicle should be of more concern when the high-speed train negotiates the curved track with disabled fasteners under the deficient super-elevation condition, and the running safety of the trailing vehicle would be in the worst situation under the surplus super-elevation condition.
Fig.7
Safety criteria vs. different vehicles and fastener failure number
(a) Derailment coefficient (350 km/h); (b) Wheelset loading reduction (200 km/h)
In Fig. 7, the pane of the dash lines indicates the corresponding limit values. When the number of the failed fasteners exceeds 20, the derailment coefficient of each vehicle reaches its limit value. When the number of the failed fasteners exceeds 25, the loading reduction of each vehicle reaches its limit value. As far as the safety operation of the high-speed train is much concerned, the limited maximum number of the failed fasteners determined by the limit value of the derailment coefficient should be preferentially considered in the track maintenance due to the fastener failure. From the general trend, the derailment coefficient and the wheelset loading reduction increase quickly with the number of failed fasteners, especially when the number of failed fasteners exceeds 15.
## 4. Conclusions
In this paper, a coupled train-track dynamic model is introduced to investigate the effect of curved track fastener failure on the dynamic behaviour of a high-speed train passing over a curved track. The investigated dynamic behaviour includes the wheel/rail forces, the ratio of the lateral force to the vertical force of the wheel and the rail, which is called the derailment coefficient, and the wheelset loading reduction. They are very important for evaluating the safety operation of high-speed trains. Through detailed numerical investigation, we have shown the dynamic characteristics of the high-speed train and the track when the train passes over the 7000-m radius curved track with different failed fastener numbers at different speeds. When the number of the continuously failed fasteners is less than 15, the train still operates normally on the curved track of 7000-m radius at the speeds of 200 km/h to 350 km/h. The obtained results are very useful in high-speed track maintenance.
* Project supported by the National Natural Science Foundation of China (No. U1134202), the National Basic Research Program (973) of China (No. 2011CB711103), and the Program for Changjiang Scholars and Innovative Research Team in University (Nos. IRT1178 and SWJTU12ZT01), China © Zhejiang University and Springer-Verlag Berlin Heidelberg 2013
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[19] Lou, P., 2007. Finite element analysis for train-track-bridge interaction system. Archive of Applied Mechanics, 77(10):707-728.
[20] National Transportation Safety Board, 1999. Railroad Accident Report, Derailment of Amtrak Train No. 4, Southwest Chief, on the Burlington Northern Santa Fe Railway near Kingman, Arizona. Report No. NTSB/RAR-98/03. National Technical Information Service,USA :
[21] Nielsen, J.C., Igeland, A., 1995. Vertical dynamic interaction between train and track-influence of wheel and track imperfections. Journal of Sound and Vibration, 187(5):825-839.
[22] Oscarsson, J., Dahlberg, T., 1998. Dynamic train/track/ballast interaction—Computer models and full-scale experiments. Vehicle System Dynamics, 29(suppl.):73-84.
[23] Popp, K., Kruse, H., Kaiser, I., 1999. Vehicle-track dynamics in the mid-frequency range. Vehicle System Dynamics, 31(5-6):423-464.
[24] Ripke, B., Knothe, K., 1995. Simulation of high frequency vehicle-track interactions. Vehicle System Dynamics, 24(suppl.):72-85.
[25] Shen, Z.Y., Hedrick, J.K., Elkins, J.A., 1984. A Comparison of Alternative Creep-force Models for Rail Vehicle Dynamic Analysis. , Proceedings of the Eighth IAVSD Symposium, Cambridge, MA, 591-605. :591-605.
[26] Sun, Y.Q., Dhanasekar, M., 2002. A dynamic model for the vertical interaction of the rail track and wagon system. International Journal of Solids and Structures, 39(5):1337-1359.
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[29] Xiao, X.B., Jin, X.S., Wen, Z.F., Zhu, M.H., Zhang, W.H., 2011. Effect of tangent track buckle on vehicle derailment. Multibody System Dynamics, 25:1-41.
[30] Xiao, X.B., Ling, L., Jin, X.S., 2012. A study of the derailment mechanism of a high-speed train due to an earthquake. Vehicle System Dynamics, 50(3):449-470.
[31] Xu, Y.L., Ding, Q.S., 2006. Interaction of railway vehicles with track in cross-winds. Journal of Fluids and Structures, 22(3):295-314.
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[34] Zhang, S.G., 2009. Design Method of High-speed Train. (in Chinese), Chinese Railway Press,Beijing, China :
[35] Zhang, W.H., 2011. Overall Technique of EMU and Bogies. (in Chinese), Chinese Railway Press,Beijing, China :
Open peer comments: Debate/Discuss/Question/Opinion
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http://www.ck12.org/arithmetic/Comparison-of-Fractions-Decimals-and-Percents/lesson/user:bHlhLnNuZWxsQGhlbnJ5LmsxMi5nYS51cw../MCC6.RP.3c-Comparison-of-Fractions-Decimals-and-Percents/
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<meta http-equiv="refresh" content="1; url=/nojavascript/">
# Comparison of Fractions, Decimals, and Percents
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Practice Comparison of Fractions, Decimals, and Percents
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MCC6.RP.3c - Comparison of Fractions, Decimals, and Percents
Have you ever had an argument with a brother or sister? Well here is one that Casey and her brother Alex had.
Casey and Alex were both working on their homework. Alex bet Casey that he could finish his homework before she did. Even though she knew it wasn't a good idea, Casey agreed to the contest. After about fifteen minutes, Alex looked over at Casey.
"I have completed $52%$ of my homework," he said.
"Well, I have completed a ratio of 3 out of 5 of my possible assignments," Casey said smirking.
Casey had meant to be a "smart alec" to Alex.
"I have more done," he returned.
"No you don't."
Who is right?
To answer this questions, you will need to know how to compare fractions, decimals and percents.
This Concept will teach you all that you need to know.
### Guidance
We have already established that fractions, decimals and percents are all related to one another. Because they are related and we can establish equivalents of each, we can also compare each using greater than, less than or equal to. We can also write them in order.
To compare fractions, decimals and percents, we should have them in the same form. If we are comparing a fraction and a percent, we have to write both of them either as fractions or percents so we can figure out which is greater.
Compare $45%$ and $\frac{4}{5}$
To compare these two quantities, first write them in the same form. Let’s change four-fifths to a percent. We do that by writing it as a fraction out of 100, which we can then change to a percent.
$\frac{4}{5}=\frac{80}{100}=80\%$
$45%$ is less than $80%$ .
Our answer is $45\% < \frac{4}{5}$ .
We can do the same thing when working with decimals and percents.
Compare $18%$ and $.9$
To complete this, we have to convert both of these to either percents or decimals. Let’s change .9 to a percent. To do this, we move the decimal point two places to the right.
.9 = 90%
18% is less than 90%.
Our answer is 18% < .9.
What about ordering fractions, decimals and percents?
When we order a set of numbers or quantities, we write them from least to greatest or from greatest to least. Fractions, decimals and percents are no exception, but it is to order them if they are in the same form.
Write .56, 34%, $\frac{9}{10}$ and $\frac{1}{2}$ in order from least to greatest
To do this, we need to write them all in the same form. Let’s convert all of them to percents.
$.56 = 56\%$
$34%$ stays the same
$\frac{9}{10} &= \frac{90}{100}=90\%\\\frac{1}{2} &= \frac{50}{100}=50\%$
So we have 56%, 34%, 90% and 50%, now it becomes easy to write them in order.
34%, 50%, 56%, and 90%
Our answer is 34%, $\frac{1}{2}$ , .56, $\frac{9}{10}$ .
Try a few of these on your own. Use greater than >, less than < or = .
#### Example A
.19 and 19%
Solution: Equal =
#### Example B
$\frac{2}{5}$ and 45%
Solution: < Less than
#### Example C
56% and 21%
Solution: > Greater than
Remember Casey and Alex? Here is the original problem once again.
Casey and Alex were both working on their homework. Alex bet Casey that he could finish his homework before she did. Even though she knew it wasn't a good idea, Casey agreed to the contest. After about fifteen minutes, Alex looked over at Casey.
"I have completed 52% of my homework," he said.
"Well, I have completed a ratio of 3 out of 5 of my possible assignments," Casey said smirking.
Casey had meant to be a "smart alec" to Alex.
"I have more done," he returned.
"No you don't."
Who is right?
To compare these two values, we need to write them both as the same thing.
Let's convert Casey's fraction to a percent. We can use an equivalent fraction out of 100.
$\frac{3}{5} = \frac{60}{100}$
Now we convert that to 60%.
Finally, we can compare the two percents.
60% and 52%
60% is greater.
Casey has completed more of her homework than Alex has.
### Vocabulary
Here are the vocabulary words in this Concept.
Percent
is "per-cent" or "per-hundred", it is a quantity written with a % sign, a part of a whole (100)
Fraction
a part of a whole, related to decimals and percents.
Decimal
a part of a whole shown by a decimal point, hundredths means two decimal places.
Equivalent
means equal
Compare
to determine whether a quantity is greater than, less than, or equal to another quantity.
Order
to write in order from least to greatest or from greatest to least.
### Guided Practice
Here is one for you to try on your own.
Write these values in order from least to greatest.
$\frac{83}{100}, .16, 33%, \frac{4}{5}$
First, we have to think in terms of parts and which values are closest to a whole.
$.16$ is a very small value. It comes first.
$33%$ is also small. It comes second.
The next two are the trickiest. We know that four -fifths is close to one whole and so is 83 out of 100. We can convert four - fifths to a fraction with a denominator of 100 so that we can easily compare these two.
$\frac{4}{5} = \frac{80}{100}$
Now we can see that four -fifths is smaller than 83 hundredths.
$.16, 33%, \frac{4}{5}, \frac{83}{100}$
### Video Review
Here is a video for review.
### Practice
Directions: Write the following values in order from least to greatest.
1. $\frac{16}{100}, .27, 53%, \frac{1}{5}$
2. $\frac{99}{100}, .30, 68%, \frac{9}{10}$
3. $\frac{18}{100}, .99, 87%, \frac{10}{20}$
4. $\frac{88}{100}, .18, 23%, \frac{1}{5}$
5. $\frac{93}{100}, .98, 6%, \frac{1}{2}$
6. $\frac{77}{100}, .37, 93%, \frac{2}{5}$
7. $\frac{12}{100}, .76, 13%, \frac{1}{3}$
8. $\frac{9}{100}, .2, 67%, \frac{4}{5}$
9. $\frac{88}{100}, .29, 35%, \frac{2}{10}$
Directions: Compare the following pairs of fractions using <,> or =.
10. $\frac{6}{7}$ and 35%
11. $\frac{3}{4}$ and 75%
12. $\frac{1}{2}$ and 55%
13. $\frac{9}{10}$ and 25%
14. $\frac{1}{4}$ and 25%
15. $\frac{1}{5}$ and 15%
### Explore More
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https://www.physicsforums.com/threads/molecular-vibration.976461/
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# A Molecular vibration
• Start date
#### Iceking20
15
1
Summary
How could we find the reduced mass for polyatomic molecule ?
Summary: How could we find the reduced mass for polyatomic molecule ?
I have problem with reduced mass of poly atomic moleculs because for diatomic molecules you can easily find out the reduced mass by M¹M²/M¹+M²,but I don't think with this way we can find reduces mass for example for fe²o³?
Related Quantum Physics News on Phys.org
#### mfb
Mentor
33,374
9,103
That will depend on the vibration mode and in general there won't be a single answer, you can't use the effective mass for everything.
I moved this thread to the quantum mechanics forum.
#### Iceking20
15
1
That will depend on the vibration mode and in general there won't be a single answer, you can't use the effective mass for everything.
I moved this thread to the quantum mechanics forum.
Can you give an example for one of the modes because I want to have perspective about it
#### A. Neumaier
6,842
2,785
Summary: How could we find the reduced mass for polyatomic molecule ?
Summary: How could we find the reduced mass for polyatomic molecule ?
I have problem with reduced mass of poly atomic moleculs because for diatomic molecules you can easily find out the reduced mass by M¹M²/M¹+M²,but I don't think with this way we can find reduces mass for example for fe²o³?
In general, the inverse reduced mass is the sum of the inverse masses of the constituents. For 2 constituents one gets your formula.
However, the concept of a reduced mass is indeed most useful for the case of 2 constituents only, where the center of mass frame leaves a 1-particle problem with the reduced mass.
For more than 2 constituents, no such simple recipe works, and the reduced Hamiltonian depends on the way relative coordinates are chosen.
#### mfb
Mentor
33,374
9,103
Can you give an example for one of the modes because I want to have perspective about it
Everything. Even if we take a molecule with three atoms in a straight, symmetric line it will have vibrations along that line (contraction/extension) and vibrations orthogonal to it (making it slightly "L"-shaped). In the first case only the outer atoms move, in the second case all atoms move.
"Molecular vibration"
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https://www.acmicpc.net/problem/6726
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시간 제한 메모리 제한 제출 정답 맞은 사람 정답 비율
1 초 128 MB 2 2 2 100.000%
문제
An obscure computer science professor wants to become famous devel- oping a new programming language YACL (“Yet Another Constant Lan- guage”). This language is very simple; it only has four constructs:
• C+1 creates the constant 1.
• C-1 creates the constant −1.
• INCR adds 1 to the constant being generated.
• DBL multiplies the constant being generated by 2.
A program in this language is a sequence of these constructs, one on each line, executed sequentially. The professor wants to keep the programs in this language simple, small, and fast. To achieve his goal, he adds the following constraints:
• Every program must begin either with C+1 or with C-1.
• A given constant C must be generated with the smallest number of instructions possible.
• If a constant C can be generated by different programs (all with equal number of instructions), then the fastest program should be used. For this purpose, suppose that the instruction DBL is executed in T nanoseconds and the instruction INCR in 2T nanoseconds.
You were hired by the professor to write several sample programs, so that he can use them at various conferences to demonstrate his powerful new language. The professor will give you a few constants, and your task is to write programs to generate these constants, obeying the constraints above.
입력
The input file may contain several instances of the problem. Each instance of the problem is just one line containing the numeric constant to be generated. All numbers are non-zero integers between −32768 and 32767. A line containing the integer zero terminates the input file.
출력
For each instance of the problem, your program should print one line saying “Constant n”, where n is the constant for that instance, followed by the most efficient program to generate that constant, one instruction per line. Insert a blank line between each instance.
예제 입력 1
3
-5
1
7
0
예제 출력 1
Constant 3
C+1
DBL
INCR
Constant -5
C-1
DBL
DBL
INCR
DBL
INCR
Constant 1
C+1
Constant 7
C+1
DBL
INCR
DBL
INCR
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http://openstudy.com/updates/515ce067e4b02fd2c0cdc613
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## anonymous 3 years ago -√3(√-3) help me pleasee Delete Cancel Submit
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1. anonymous
• 3 years ago
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$$\sqrt{-3}=\sqrt{3}i$$
2. anonymous
• 3 years ago
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i know this is with i agai
3. anonymous
• 3 years ago
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so $-\sqrt{3}\times \sqrt{3}i=-3i$
4. anonymous
• 3 years ago
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ohh so anything with a negative is and imaginary number right
5. anonymous
• 3 years ago
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if you have a negative number inside the radical, then it comes outside as $$i$$
6. anonymous
• 3 years ago
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yeah because a negative isnt possible in square root
7. anonymous
• 3 years ago
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for example $$\sqrt{-25}=\sqrt{25}i=5i$$ and $\sqrt{-3}=\sqrt{3}i$
8. anonymous
• 3 years ago
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i have a few more question like this can i show you and can you tell me if im doing it right?
9. anonymous
• 3 years ago
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√-25√-9 its going to be 5i 3i right?
10. anonymous
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yes, that would be the first step
11. anonymous
• 3 years ago
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the second step would be to actually multiply and get $5i\times 3i=15i^2=15\times (-1)=-15$
12. anonymous
• 3 years ago
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the i goes away?
13. anonymous
• 3 years ago
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yes, because $$i=\sqrt{-1}$$ and so $$i^2=-1$$
14. anonymous
• 3 years ago
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oh that makes sense and im sorry i just have two more if u could please check them as well (6i)2 which would be 36i right but if i multiplied 36 by -1 then i get -36 then theres (2+3)(2-3i) im not sure about this one like is it going to be like 5*2-3(-1) ?
15. anonymous
• 3 years ago
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thanks for helping me out im stuck with all this and guys are the best :D
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http://weblib.cern.ch/collection/General%20Talks?ln=zh_CN
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# General Talks
Subscribe to the General Talks video podcast [?]
2020-07-15
09:22
div.thumbMosaic {display:inline;} div.thumbMosaic span{display:none;} div.thumbMosaic:hover span{display:block;position:absolute;z-index:2;} Theory: Exited states, charmonia / Karliner, Marek (speaker) (Tel Aviv University (IL)) ; Karliner, Marek (speaker) (Tel Aviv University (IL)) 2020 - 0:32:26. Conferences; 8th Edition of the Large Hadron Collider Physics Conference External links: Talk details; Event details In : 8th Edition of the Large Hadron Collider Physics Conference
2020-07-14
14:38
div.thumbMosaic {display:inline;} div.thumbMosaic span{display:none;} div.thumbMosaic:hover span{display:block;position:absolute;z-index:2;} Studies of phase diagram of strongly interacting matter at the CERN SPS / Gazdzicki, Marek (speaker) (Goethe University Frankfurt (DE)) Twenty years ago, the seven experiments on CERN's Heavy Ion programme at the Super Proton Synchrotron (NA44, NA45/CEREA,NA49, NA50,NA52/NEWMASS, WA97/NA57 and WA98) combining their data were able to characterise a new state of matter, verifying an important prediction of the theory of fundamental forces between quarks. This talk briefly reviews studies of the phase diagram of strongly interacting matter with relativistic nuclear collisions at the CERN Super Proton Synchrotron which followed the observation of the quark-gluon plasma. The first ten years of this period was mostly influenced by results of the NA49 experiment, the second period was dominated by NA61/SHINE. I will close by suggesting priorities for future measurements. 2020 - 1:17:41. EP Seminar External link: Event details In : Studies of phase diagram of strongly interacting matter at the CERN SPS
2020-07-10
14:21
div.thumbMosaic {display:inline;} div.thumbMosaic span{display:none;} div.thumbMosaic:hover span{display:block;position:absolute;z-index:2;} Building scalable and reliable monitoring systems / Tsvetkov, Nikolay (speaker) (CERN) 2020 - 0:58:15. CERN openlab Summer Student programme 2020; Building scalable and reliable monitoring system External links: Talk details; Event details In : Building scalable and reliable monitoring system
2020-07-09
09:03
div.thumbMosaic {display:inline;} div.thumbMosaic span{display:none;} div.thumbMosaic:hover span{display:block;position:absolute;z-index:2;} Unit 11 - Mechanical design: structures / Todesco, Ezio (speaker) (CERN) This units belongs to the fourth part of the course, focussed on magnet design. Here we discuss the mechanical structure to support the dipole and quadrupole coils. We start with the collar concept, introduced with Tevatron magnets. [...] 2020 - 1:12:13. Masterclass - Superconducting Accelerator Magnets External link: Event details In : Unit 11 - Mechanical design: structures
2020-07-06
09:48
div.thumbMosaic {display:inline;} div.thumbMosaic span{display:none;} div.thumbMosaic:hover span{display:block;position:absolute;z-index:2;} Unit 10 - Mechanical design: forces, stresses and the preload paradigm / Todesco, Ezio (speaker) (CERN) This units belongs to the fourth part of the course, focussed on magnet design. Here we discuss the pattern of the electromagnetic forces acting on a dipole and on a quadrupole coil. We first give an analytical estimate of the accumulation of prestress in the midplane for dipoles and quadrupoles based on sector coils [...] 2020 - 1:22:10. Masterclass - Superconducting Accelerator Magnets External link: Event details In : Unit 10 - Mechanical design: forces, stresses and the preload paradigm
2020-07-06
08:58
div.thumbMosaic {display:inline;} div.thumbMosaic span{display:none;} div.thumbMosaic:hover span{display:block;position:absolute;z-index:2;} Flash Talk 2 / Chen, Lin (speaker) (Central China Normal University) 2020 - 0:04:56. Conferences; 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions External links: Talk details; Event details In : 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions
2020-07-03
12:37
div.thumbMosaic {display:inline;} div.thumbMosaic span{display:none;} div.thumbMosaic:hover span{display:block;position:absolute;z-index:2;} Lattice and Effective Field Theories for Hard Probes / brambilla, Nora (speaker) 2020 - 0:25:41. Conferences; 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions External links: Talk details; Event details In : 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions
2020-07-02
09:40
div.thumbMosaic {display:inline;} div.thumbMosaic span{display:none;} div.thumbMosaic:hover span{display:block;position:absolute;z-index:2;} Flash Talk 5 / Park, Jonghan (speaker) (Inha University (KR)) 2020 - 0:04:51. Conferences; 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions External links: Talk details; Event details In : 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions
2020-07-01
13:19
div.thumbMosaic {display:inline;} div.thumbMosaic span{display:none;} div.thumbMosaic:hover span{display:block;position:absolute;z-index:2;} Recent results on open heavy flavour with ALICE (by F.G.) - Recent results on jets and high-pT hadrons with ALICE (by L.B.H.) / Grosa, Fabrizio (speaker) (Universita e INFN Torino (IT)) ; Havener, Laura Brittany (speaker) (Yale University (US)) First talk (30'): Heavy flavours are recognised as excellent probes of the colour-deconfined state of the hadronic matter called quark-gluon plasma (QGP) created in heavy-ion collisions. Due to the very short time scale characterising their production, they experience the whole evolution of the system serving as Brownian-motion markers of the QGP [...] 2020 - 1:17:27. LHC Seminar External link: Event details In : Recent results on open heavy flavour with ALICE (by F.G.) - Recent results on jets and high-pT hadrons with ALICE (by L.B.H.)
2020-07-01
13:10
div.thumbMosaic {display:inline;} div.thumbMosaic span{display:none;} div.thumbMosaic:hover span{display:block;position:absolute;z-index:2;} $J/\psi$ production in jets in p+p collisions at $\sqrt{s}$ = 500 GeV by STAR / Yang, Qian (speaker) (Shandong University) The suppression of $J/\psi$ production caused by the color-screening effect in heavy-ion collisions is considered as an evidence of the creation of quark-gluon plasma. To interpret the observed suppression in heavy-ion collisions, a good understanding of its production mechanism in p+p collisions is needed. [...] 2020 - 0:19:24. Conferences; 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions External links: Talk details; Event details In : 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions
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http://www.eevblog.com/forum/microcontrollers/next-step-from-avr/50/
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### Author Topic: Next step from AVR (Read 2346 times)
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#### rstofer
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##### Re: Next step from AVR
« Reply #50 on: October 19, 2018, 02:54:29 am »
Right now there is no useful RISC-V hardware, there is nothing to talk about. And suggesting it to newbies moving from AVR is plain cruel.
Why cruel? He's a hobbyist. He doesn't have a boss who yells at him every morning pressing for results (whatever this is in his mind). Why do you think that repeating LED blinking/LCD driving exercises with STM (after he already did exactly that with Arduino) will fill him with joy? Looking at the first ever open-source RISC-V processor, which does not yet have a fully operational ecosystem, may be something differed and much more rewarding. I think Bruce is absolutely right suggesting this. OP is free to choose what he likes.
OK, I somehow got interested in the FE310 board. It starts out with a 48 pin chip so, by definition, IO is limited when compared to a 100 pin chip. But it does have a UART, 3 PWMs and SPI (master only) with 3 slave selects. Getting to the details is going to take a bit more reading. It's also fast!
It uses an external Quad SPI flash for program storage (there is a 16 kB internal instruction cache) and it has 16 kB of data SRAM. AFAICT, there is no analog input or DAC output (other than PWM). There doesn't seem to be support for Ethernet (like in the LPC1768, among others). No USB Host or Device AFAICT.
So, pretty spartan by some measures. But, as pointed out, this is just one implementation. Something to get started with. But, at $59, it's kind of expensive when I can buy an Arduino Nano for about$5. And the Arduino Nano is pretty well understood. I'm not comparing speed here, the Nano is SLOW! The RISC-V is FAST!
Intertia, that's the problem. Static inertia says "Nobody is using this, prototype projects aren't available, why bother?" and dynamic inertia says "I'm using ARM, it's a RISC core, why bother?".
The ISA is irrelevant to the user in most cases. They want to pump C in one end and having blinking and flashing come out the other end. At the hobby level, I'd be willing to bet that most users don't know, nor do they care, how the NVIC works.
Think of how different the PIC, AVR and ARM ISAs are. They are wildly different and, yet, the PIC 16F series is still being sold. By the bazillions!
#### Siwastaja
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• Posts: 1441
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##### Re: Next step from AVR
« Reply #51 on: October 19, 2018, 03:52:25 am »
IMHO, if brucehoult's company wants to succeed on the microcontroller or embedded market, the ways to get there is:
1) Try to forget your great RISC-V core for a second
2) Try to come up with flexible and numerous peripherals, and
3) Document them clearly.
The managers who want the ARM core on Powerpoint are hard to convince anyway. They need the inertia the most.
But, there are engineer-like managers as well, and sometimes even engineers can make the component decisions. This is where good peripheral sets totally shine, since most engineers are not that interested about the core, as long as it has the basic tool support. This is a free advice for brucehoult, but IMHO they should try to concentrate on the peripherals from day one - and here I can see a huge opportunity for the configurability: Every core licensing company has the same graphical toolset you can use to "design your CPU", meaning, choose whether you have a hardware divider or not, or select the amount of cache, and so on...
No one has done the same for peripherals on a level that would allow building a modern microcontroller. This could be huge; look at high-end microcontrollers that always implement easily over 100 peripherals, of over 30-40 different types, just that the user can use 5 of them and leave the rest unused. Maybe there would be market for custom SoCs in this $5-$15 mid-to-high-end microcontroller market?
« Last Edit: October 19, 2018, 04:24:26 pm by Siwastaja »
#### mark03
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• Posts: 422
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##### Re: Next step from AVR
« Reply #52 on: October 19, 2018, 04:01:12 am »
If you want to start playing with an IDE for STM32 (or any other ARM Cortex-M line) that is truly plug-and-play, it's worth mentioning that the free (code-size-limited) version of IAR is pretty capable. You're unlikely to hit the code-size limit on a hobby project, as long as you don't use the vendor-supplied peripheral drivers (HAL), which as a hobbyist, you shouldn't.
Obvious drawbacks: Windows only, and a regular license costs serious money. As a student you would likely be better served by learning how to roll your own gcc-based toolchain. OTOH, IAR is very widely used in for-profit embedded development, so you might look at it as a job skill, although any engineer worth their salt should be able to pick up a new IDE quickly.
As for STM32 vs PSOC vs others, really, just pick one... they have far more in common than their differences.
#### brucehoult
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• Currently at SiFive, previously Samsung R&D
##### Re: Next step from AVR
« Reply #53 on: October 19, 2018, 10:06:57 am »
No one has done the same for peripherals on a level that would allow building a modern microcontroller. This could be huge; look at high-end microcontrollers that always implement easily over 100 peripherals, of over 30-40 different types, just that the user can use 5 of them and leave the rest unused. Maybe there would be market for custom SoCs in this $5-$15 mid-to-high-end microcontroller market?
Funny you should say that. Already done and in testing internally, switched on for the public soon: https://www.sifive.com/chip-designer
There are already hundreds of IP blocks licensed from various DesignShare partners under a deal where you pay no license fee until you go into volume production.
Both the FE310 and FU540 have been recreated using this flow and taped out to TSMC.
#### legacy
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##### Re: Next step from AVR
« Reply #54 on: October 19, 2018, 11:18:10 am »
But, at $59, it's kind of expensive when I can buy an Arduino Nano for about$5
Yesterday I went to the restaurant for a business meeting, and when I went out, a few colleagues were complaining they were still hungry because the dishes haven't been filled to the brim and for 60 euro per head it was rather expensive.
The cook was nearby and heard, so he answered something like "well if you compare the street food with a tasting of excellence, you can do similar complaints
the Bunker is open!
(shortcut)
#### brucehoult
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• Currently at SiFive, previously Samsung R&D
##### Re: Next step from AVR
« Reply #55 on: October 19, 2018, 12:31:21 pm »
So, pretty spartan by some measures. But, as pointed out, this is just one implementation. Something to get started with. But, at $59, it's kind of expensive when I can buy an Arduino Nano for about$5.
A fair assessment (not only the part I quoted).
You can by the way buy bare FE310 chips for $25 for 5, and there is also the "LoFive" design done by a 3rd party. The board design is open source, you can make it yourself, and there have been a couple of GroupGets campaigns for assembled LoFives for$25.
https://groupgets.com/manufacturers/qwerty-embedded-design/products/lofive-risc-v
#### rstofer
• Super Contributor
• Posts: 5279
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##### Re: Next step from AVR
« Reply #56 on: October 19, 2018, 12:54:58 pm »
So, pretty spartan by some measures. But, as pointed out, this is just one implementation. Something to get started with. But, at $59, it's kind of expensive when I can buy an Arduino Nano for about$5.
A fair assessment (not only the part I quoted).
You can by the way buy bare FE310 chips for $25 for 5, and there is also the "LoFive" design done by a 3rd party. The board design is open source, you can make it yourself, and there have been a couple of GroupGets campaigns for assembled LoFives for$25.
https://groupgets.com/manufacturers/qwerty-embedded-design/products/lofive-risc-v
I just looked briefly but I did want to be fair because I just might be interested. Sure, the board is pricey but so what, education has never been free. I have a couple of dozen development boards going back 15 years or more. I don't regret buying any of them. OTOH, I'm not sure what to do with some of them...
There's quite a bit of documentation and it seems quite thorough. I don't recall seeing such detail of the internal logic with any other device.
I mainly playing with FPGAs and the PSOC 6 at the moment but that can change in an instant. Sometimes I think I bounce around like a BB in a bowling alley.
Bare chips for $5 seems very interesting. I prefer to use pre-manufactured boards but I have designed some from time to time. Mostly I design daughter cards to break out various IO from the factory headers. #### brucehoult • Frequent Contributor • Posts: 919 • Country: • Currently at SiFive, previously Samsung R&D ##### Re: Next step from AVR « Reply #57 on: October 19, 2018, 02:31:50 pm » Bare chips for$5 seems very interesting. I prefer to use pre-manufactured boards but I have designed some from time to time. Mostly I design daughter cards to break out various IO from the factory headers.
Bare chips are here: https://www.crowdsupply.com/sifive/hifive1
Smf
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https://www.physicsforums.com/threads/a-square-matrix-a-with-ker-a-2-ker-a-3.532199/
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# A square matrix A with ker(A^2)= ker (A^3)
1. Sep 20, 2011
### yeland404
1. The problem statement, all variables and given/known data
a square matrix A with ker(A^2)= ker (A^3), is ker(A^3)= ker (A^4),verify...
2. Relevant equations
3. The attempt at a solution
2. Sep 20, 2011
### micromass
Staff Emeritus
3. Sep 20, 2011
### yeland404
it means that A^2*vector x= 0 and A*x=0 has same result,then I really confused how to do the next step
4. Sep 20, 2011
### micromass
Staff Emeritus
No, it means that
$$A^2x=0~\Leftrightarrow~A^3x=0$$
You need to prove that
$$A^3x=0~\Leftrightarrow~A^4x=0$$
5. Sep 20, 2011
### yeland404
emm...., to the difinition it says that ker(A) is T(x)=A(x)=0
6. Sep 20, 2011
### micromass
Staff Emeritus
Yes, but you're not working with ker(A) here, but with ker(A2).
7. Sep 20, 2011
### yeland404
should define a matrix A and write A^2 as dot product of A & A,and also to A^3...it seems to be so complex, or use the block to devide the matrix into some small matrix?
8. Sep 20, 2011
### micromass
Staff Emeritus
Do you understand my Post 4??
9. Sep 20, 2011
### yeland404
so times A on both side of the equation?
10. Sep 20, 2011
### micromass
Staff Emeritus
No, you need to prove two things:
If $A^3x=0$, then $A^4x=0$. This can indeed be accomplished by multiplying sides with A.
But you also need to prove that if $A^4x=0$, then $A^3x=0$.
11. Sep 26, 2011
### yeland404
so Ker (A^2)=0 can lead to Ker(A^4)=0,then?
12. Sep 26, 2011
### HallsofIvy
Staff Emeritus
NO ONE has said that Ker(A^2)= 0 so I do not understand why you are asking this question. You seem, frankly, to have no idea what the question is saying. ker(A^2)= ker(A^3) means, as micromass said, "A^2x= 0 if and only if A^3x= 0". You want to use that to prove "A^3x= 0 if and only if A^4x= 0". As micromass said, the first part is easy: if A^3x= 0 then, applying A to both sides, A^4x= A0= 0 which proves that ker(A^3) is a subset of ker(A^4). You still need to prove the other way: if A^4x= 0, then A^3= 0. You cannot just multiply by A^{-1} because you have no reason to think that A is invertible. But notice that ker(A^2)= ker(A^3) has not yet been used so it might help to note that A^4x= A^2(A^2x).
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https://sebastiansauer.github.io/dplyr_strings/
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# More on programming with dplyr: converting quosures to strings
In this post, we have programmed a simple function using dplyr’s programming capabilities based on tidyeval; for more intro to programming with dplyr, see here.
In this post, we’ll go one step further and programm a function where a quosure will be turned to a string. Why this? Because quite a number of functions out there except strings as input parameters.
# Libraries
library(tidyverse)
library(stringr)
# Data example
Say, we have a string where we search for a word stem. However this stem does not appear in its “stem” form, but always with some suffixes. Let our stem be “spd” (the name of the German Social-Democratic party), and (for simplicity), we’ll assume two “instances” of “spd” that occurr with suffix, ie., “spdbt” and “spdde”. (I was just working on a text mining on Tweets of German politiicians, hence the example).
data <- c("spdde", "sdf", "sdf", "fdds", "spdde", "dsf", "spdbt", "df") %>% as_tibble
stem <- "spd"
# Task 01: Extract the “spd” stem out of the data
Non-programmatically, ie., interactively, this is quite straight-forward. Some knowledge of Regex is helpful to render the task a bit more general:
data %>%
mutate(is_instance = str_detect(string = value, pattern = "spd\\w+"),
instance = str_match(value, "spd\\w+"))
## # A tibble: 8 x 3
## value is_instance instance
## <chr> <lgl> <chr>
## 1 spdde TRUE spdde
## 2 sdf FALSE <NA>
## 3 sdf FALSE <NA>
## 4 fdds FALSE <NA>
## 5 spdde TRUE spdde
## 6 dsf FALSE <NA>
## 7 spdbt TRUE spdbt
## 8 df FALSE <NA>
\\w means “find a word-character” (ie., letter or digit), and + means that at least 1 hit is expected. pattern is the pattern to be looked for and string defines the string where to search for the pattern.
# Task 02: Make it a function
Obviously, a function is much more general. Say we have 10 parties we would like to warp through; it becomes tedious to repeat that code many times. We will want a function. How to do that with dplyr?
Let’s define a function with input parameters df for the name of the dataframe, col for the name of the column where the stemming is performend, and stem, the term to be stemmed.
stemm_col <- function(df, col, stem){
col <- enquo(col)
col_name <- quo_name(enquo(col))
stem_name <- quo_name(enquo(stem))
df %>%
mutate(stemmed = str_extract(string = !!col,
pattern = paste0(stem_name,"\\w+"))) -> output
return(output)
}
See whether it runs:
stemm_col(df = data, col = value, stem = "spd")
## # A tibble: 8 x 2
## value stemmed
## <chr> <chr>
## 1 spdde spdde
## 2 sdf <NA>
## 3 sdf <NA>
## 4 fdds <NA>
## 5 spdde spdde
## 6 dsf <NA>
## 7 spdbt spdbt
## 8 df <NA>
# Bit by bit explanation
• col <- enquo(col) – Take the parameter col, and just remember, R, that it is an expression, in this case, the parameter of a function, denoting a column.
• col_name <- quo_name(enquo(col)) – Now turn col (an expression) to a string, because the function further down (str_extract) expects a string.
• str_extract(string = !!col,... – Hey R, when you extract the strings, you need to know which string to search. OK, take col which is an expression, and now evaluate it (indicated by !!), in this case, understand that it’s a column. Now go get the values.
# Main idea
When working with NSE, it is important to distinguish between expression, strings and evaluation. Using NSE, we can look at the parameters of a function, and grap the parameters before they are evaluated. That’s why the parameters need not be well-behaved, importantly, they do not need to have quotation marks, which saves typing for the user.
From the perspective of the R-interpreter (the machine), the steps of action looks more or less like this:
1. Look at the parameters of the function
2. Save the parameters not as strings, not as variables, but as expressions (via enquo)
3. Convert the expression to a string (via quo_name) or, eventually,
4. Evaluate it, ie., unquote (let the function to its job) via !! (called bang-bang) or via UQ.
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https://www.oreilly.com/library/view/valve-amplifiers-4th/9780080966403/xhtml/chp007_a.xhtml
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## With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.
No credit card required
where
k=Boltzmann’s constant ≈1.381×10−23 J/K
T=absolute temperature in K=°C+273.16
B=bandwidth in Hz
R=resistance in Ω.
For a typical internal temperature of 40°C (313 K), with a bandwidth of 20 kHz, this is more conveniently expressed as:
${v}_{\mathrm{n}}=1.86×{10}^{-8}\sqrt{R}$
Using this equation, we find that a perfect 100 kΩ resistor generates 5.9 μV of thermal noise. In this instance, the resistor’s thermal noise has been greatly exceeded by its excess noise. To find the total noise of the resistor, we must add the individual noise powers, which, if we remember that
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https://www.physicsforums.com/threads/gravitational-field-question.271949/
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# Gravitational Field Question
1. Nov 14, 2008
### jessedevin
1. The problem statement, all variables and given/known data
Three objects -- two of mass m and one of mass M -- are located at three corners of a square of edge length l. Find the gravitational field g at the fourth corner due to these objects. (Express your answers in terms of the edge length l, the masses m and M, and the gravitational constant G).
2. Relevant equations
g=-GM/r2
3. The attempt at a solution
g= ga+gb+gc
g= Gm/l2 $$\hat{i}$$+ (GM/(l$$\sqrt{2}$$)2)(cos($$\pi/4$$)$$\hat{i}$$+sin($$\pi/4$$)$$\hat{j}$$)+Gm/l2 $$\hat{j}$$
I know you have to take the magnitude of this, but when I did that , I still get the wrong answer. Here's what I got:
||g||=$$\sqrt{2G^2/l^4(m^2+M^2)}$$
Did I start it right? Can someone help?
Last edited: Nov 14, 2008
2. Nov 14, 2008
### LowlyPion
Isn't the gravitational field given by GM/r ?
You have 3 vectors to add, but happily the 2 m's at right angles gives one lying in the direction of M
So ... √2Gm/L + GM/(√2*L) = √2*G*(m + M/2)/L ?
3. Nov 14, 2008
### jessedevin
So do you take the magnitude of that? Im still confused, because my book says otherwise. Can you go through your process?
4. Dec 2, 2008
### SonHa
I think what you did originally is correct, but it ask for the magnitude without the vector sign. So just put down the answer using c^2 = a^2 + b^2 and then I believe you have to indicate the degree according to the x-axis. I'm doing a similar problem. Wait, yeah you did that, never mind.
5. Dec 2, 2008
### SonHa
I got it!
Instead of converting M vectors into g forces of x and y, why don't you convert the other 2 m mass into direction of M which is Gm/l^2 * cos(45) * 2.
Then add it to the g force of M
My answer is (1.41Gm + 0.5GM)/l^2.
Hope it helps, the post was like half a month ago, lol.
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https://www.physicsforums.com/threads/bsphys-actual-jobs-available.205257/
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# BSPhys actual jobs available?
1. Dec 18, 2007
### cdotter
I don't really know how to start this, so I'll get to the point:
I'll be going to university in the fall because as it turns out being a minimum wage slave is horrible...anyways, my choice of major is a tossup between Physics and Computer Information Systems. I took Physics and AP Calculus my senior year in high school and I loved it. The material was interesting and I did very well in both classes, but I was an idiot and didn't bother taking the AP test because I didn't want to spend the $80. So I guess my point is that I like math and I'm not too bad at it. So, if my college career will be anything like my high school career, let's assume I'll graduate in four years with a BS in Physics with a 3.4 GPA. I don't have any research or job experience because my university doesn't offer internships for Physics students and the internships I've found on my own are thousands of miles away and don't pay. Now what? I'll be around$40,000 in debt from student loans. I would like to go on to graduate school for a Masters, but my debt dictates that I work for a bit to pay off my loans. What types of jobs are available? I've heard that finance jobs are available to Physics majors because they are good at maths and are great critical thinkers...but I'm not Mr. 4.0-GPA-Ivy-Leaguer, I'm an average student with a degree from a small liberal arts university with no related job experience...which leads me to believe I won't be qualified for these jobs. Not that I'd like to work in finance, however.
So, is it possible to get an industry job with just a BS in Physics? I've heard that Physics students can do engineering jobs...and I've heard they can't. I suppose to depends on who is in HR and what exactly the job is, but generally, would a Physics major stand a chance at getting an Engineering job? If not, what other math and science jobs would be available to an average student with a BS in Physics?
Thanks.
2. Dec 18, 2007
### RasslinGod
3. Dec 19, 2007
### mattmns
Learn some computer skills on top of your physics and you could probably find something.
4. Dec 19, 2007
### fizziks
If you want to find work with JUST a BS physics degree, you cannot, unless you specialize in something useful/required by the employer. Take some computer classes with your physics degree. If your school offers anything in engineering, take some of their classes. Make computer programs during your undergrad.
Taking programming classes mean jacksh*t to employers unless you have some way in providing hard evidence that you can do it. My cousin works for M\$ as a hiring contact and he doesn't give a sh&t if you are a CS major unless you can provide a sample of your code. So if you don't want to take programming classes, learn it yourself and make programs.
You cannot get an engineering job with a physics degree unless you have taken engineering classes or have prior experience in engineering.
5. Dec 19, 2007
### arunma
Hi Cdotter. There was already a thread along similar lines, posted by Fizziks. My recommendation is this: double major in physics and engineering. It's not that hard, since many of the courses overlap. I had a friend in undergrad who doubled in physics and chemical engineering. He went to law school to be a patent lawyer. But if he hadn't gone that route, he'd have a decent job waiting for him.
Here's my understanding as a first year grad student (if anyone knows better, please correct me). Even if you graduate with student loans to pay off, you can get those deferred as long as you go to grad school immediately after college. So contrary to your earlier assumption, you can go for a Master's degree. I assume you'd want to get a Master's in physics, and with this you'll be a much stronger candidate for many jobs. But let's say you graduate and decide you don't want to do two more years of school. Or, let's say you don't have the GPA/GRE scores to get into grad school. You'll still have your engineering degree, which would make you quite employable.
So I think that doubling in physics and engineering is your best bet. The courses overlap, you can go to grad school if you still like physics at the end of it all, and you still have options if you want to start making money.
6. Dec 19, 2007
### Shackleford
What about a physics major with a mechanical engineering minor?
7. Dec 19, 2007
### Laura1013
That's really not true. It may be more difficult, but it happens all the time. None of the people I know with just a bachelor's in physics who currently work as engineers had any prior engineering experience. It's most definitely possible.
8. Dec 19, 2007
### Defennder
Are you sure they weren't hired because they had marketable skills outside of physics, ie. programming etc.?
9. Dec 19, 2007
### ice109
you can't get a minor in a technical major
10. Dec 19, 2007
### Shackleford
You don't know what you're talking about. UH offers a Mechanical Engineering minor.
11. Dec 19, 2007
### Defennder
You know I think it's better if you did it the other way round; engineering major with a physics minor.
12. Dec 19, 2007
### Shackleford
I'm majoring in physics, not engineering. I'm just looking for a minor that will give me better employment opportunities.
13. Dec 19, 2007
### Asphodel
Physics + Engineering minor sounds good for that. Or Chemistry, Biology, English, et cetera. Probably no one cares about your Math minor, everybody has those or nearly so.
14. Dec 19, 2007
### Shackleford
If I do an ME minor, some of the classes will kind of overlap with my physics major, so I might be doing some of the same topics twice. I guess that could be a bit advantageous, but I kind of want an "easier" minor, maybe business, to give me more employment opportunities.
15. Dec 19, 2007
### clope023
x2, my university offers 4 different tracks (robotics/mechatronics, materials, etc) for mechanical engineering minors.
16. Dec 19, 2007
### Poop-Loops
Yeah, same here. I really don't understand where you got your info from, fizziks. Sounds like a load of crap to me.
17. Dec 19, 2007
### Shackleford
Hey, guys, I perused a bit over the minors at UH. The minor in architecture seems interesting to me. I've always been a bit fascinated by skyscrapers, buildings, and so forth. Is there practical employment use for such a minor?
Maybe a minor in the following?
http://www.tech.uh.edu/Departments/Engineering_Technology/Minors/ [Broken]
Last edited by a moderator: May 3, 2017
18. Dec 19, 2007
### Asphodel
Minors are rarely of "practical employment use" beyond one factor - if you take a cohesive bundle of electives that form a minor, they give you an easy way to document it. If it looks fun, or if you'll cover enough material that will be useful towards your career plans, then by all means go for it.
19. Dec 19, 2007
### Shackleford
Well, I'm not exactly sure yet what I want to do with my physics degree. I'm majoring in it because physics thoroughly interests me. I suppose research would be interesting as would industry.
20. Dec 20, 2007
### fizziks
Personal experience. Fellow recent graduates with physics degrees. Show me hard evidence of employers hiring physics graduates for entry level engineering positions with no engineering experience or specialization because I couldn't find one for the past 3-4 months. Checked craigslist, usajobs, monster.com, etc. Even tried networking with a couple of online friends.
So I'm stuck looking for a job with the skills I already have that was not taught in school (C++, CSS, computer skills, etc.). I wouldn't say my 4-year degree was useless, it'll give me the edge on what I know now.
Similar Discussions: BSPhys actual jobs available?
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https://kar.kent.ac.uk/64723/
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# Mixed-Size Concurrency: ARM, POWER, C/C++11, and SC
Flur, Shaked and Sarkar, Susmit and Pulte, Christopher and Nienhuis, Kyndylan and Maranget, Luc and Gray, Kathryn E. and Sezgin, Ali and Batty, Mark and Sewell, Peter (2017) Mixed-Size Concurrency: ARM, POWER, C/C++11, and SC. In: Proceedings of the 44th ACM SIGPLAN Symposium on Principles of Programming Languages. POPL Principles of Programming Languages . ACM, New York, USA, pp. 429-442. ISBN 978-1-4503-4660-3. (doi:10.1145/3009837.3009839)
PDF - Pre-print
Preview
Official URL
http://dx.doi.org/10.1145/3009837.3009839
## Abstract
Previous work on the semantics of relaxed shared-memory concurrency has only considered the case in which each load reads the data of exactly one store. In practice, however, multiprocessors support mixed-size accesses, and these are used by systems software and (to some degree) exposed at the C/C++ language level. A semantic foundation for software, therefore, has to address them.
We investigate the mixed-size behaviour of ARMv8 and IBM POWER architectures and implementations: by experiment, by developing semantic models, by testing the correspondence between these, and by discussion with ARM and IBM staff. This turns out to be surprisingly subtle, and on the way we have to revisit the fundamental concepts of coherence and sequential consistency, which change in this setting. In particular, we show that adding a memory barrier between each instruction does not restore sequential consistency. We go on to extend the C/C++11 model to support non-atomic mixed-size memory accesses.
This is a necessary step towards semantics for real-world shared-memory concurrent code, beyond litmus tests.
Item Type: Book section 10.1145/3009837.3009839 Q Science > QA Mathematics (inc Computing science) > QA 75 Electronic computers. Computer science Faculties > Sciences > School of Computing > Programming Languages and Systems Group Mark Batty 24 Nov 2017 14:45 UTC 24 Sep 2019 08:40 UTC https://kar.kent.ac.uk/id/eprint/64723 (The current URI for this page, for reference purposes)
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https://worldwidescience.org/topicpages/o/open+active+site.html
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#### Sample records for open active site
1. Multiple Coordination Exchanges for Room-Temperature Activation of Open-Metal Sites in Metal-Organic Frameworks.
Science.gov (United States)
Bae, Jinhee; Choi, Jae Sun; Hwang, Sunhyun; Yun, Won Seok; Song, Dahae; Lee, JaeDong; Jeong, Nak Cheon
2017-07-26
The activation of open coordination sites (OCSs) in metal-organic frameworks (MOFs), i.e., the removal of solvent molecules coordinated at the OCSs, is an essential step that is required prior to the use of MOFs in potential applications such as gas chemisorption, separation, and catalysis because OCSs often serve as key sites in these applications. Recently, we developed a "chemical activation" method involving dichloromethane (DCM) treatment at room temperature, which is considered to be a promising alternative to conventional thermal activation (TA), because it does not require the application of external thermal energy, thereby preserving the structural integrity of the MOFs. However, strongly coordinating solvents such as N,N-dimethylformamide (DMF), N,N-diethylformamide (DEF), and dimethyl sulfoxide (DMSO) are difficult to remove solely with the DCM treatment. In this report, we demonstrate a multiple coordination exchange (CE) process executed initially with acetonitrile (MeCN), methanol (MeOH), or ethanol (EtOH) and subsequently with DCM to achieve the complete activation of OCSs that possess strong extracoordination. Thus, this process can serve as an effective "chemical route" to activation at room temperature that does not require applying heat. To the best of our knowledge, no previous study has demonstrated the activation of OCSs using this multiple CE process, although MeOH and/or DCM has been popularly used in pretreatment steps prior to the TA process. Using MOF-74(Ni), we demonstrate that this multiple CE process can safely activate a thermally unstable MOF without inflicting structural damage. Furthermore, on the basis of in situ (1)H nuclear magnetic resonance ((1)H NMR) and Raman studies, we propose a plausible mechanism for the activation behavior of multiple CE.
2. Simultaneous presence of both open metal sites and free functional organic sites in a noncentrosymmetric dynamic metal-organic framework with bimodal catalytic and sensing activities.
Science.gov (United States)
Saha, Rajat; Joarder, Biplab; Roy, Anupam Singha; Manirul Islam, Sk; Kumar, Sanjay
2013-12-02
Assimilation of open metal sites (OMSs) and free functional organic sites (FOSs) with a framework strut has opened up a new route for the fabrication of novel metal-organic materials, thereby providing a unique opportunity to explore their multiple functionalities. A new metal-organic framework (MOF), {[Cu(ina)2(H2O)][Cu(ina)2(bipy)]·2H2O}n (1) (ina=isonicotinate, bipy=4,4'-bipyridine), has been synthesized and characterized. Complex 1 is crystallized in the orthorhombic noncentrosymmetric space group Aba2 and consists of two different 2D coordination polymers, [Cu(ina)2(H2O)]n and [Cu(ina)2(bipy)]n, with entrapped solvent water molecules. Hydrogen-bonding interactions assemble these two different 2D coordination layers in a single-crystal structure with interdigitation of pendant 4,4'-bipy from one layer into the groove of another. Upon removal of guest molecules, 1 undergoes a structural transformation in single-crystal-to-single-crystal fashion with expansion of the effective void space. Each metal center is five-coordinated and thus can potentially behave as an OMS, and the free pyridyl groups of pendant 4,4'-bipy moieties and free -C=O groups can act as free FOSs. Thus, owing to presence of both OMSs and free FOSs, the framework exhibits multifunctional properties. Owing to the presence of OMSs, the framework can act as a Lewis acid catalyst as well as a small-molecule sensor material, and in a similar way, owing to the presence of free FOSs, it performs as a Lewis base catalyst and a cation sensor material. Furthermore, owing to noncentrosymmetry with large polarity along a particular direction, it shows strong second-harmonic generation/nonlinear optical (SHG-NLO) activity. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
3. A microporous Cu-MOF with optimized open metal sites and pore spaces for high gas storage and active chemical fixation of CO2.
Science.gov (United States)
Gao, Chao-Ying; Tian, Hong-Rui; Ai, Jing; Li, Lei-Jiao; Dang, Song; Lan, Ya-Qian; Sun, Zhong-Ming
2016-09-25
A microporous Cu-MOF with optimized open metal sites and pore space was constructed based on a designed bent ligand; it exhibits high-capacity multiple gas storage under atmospheric pressure and efficient catalytic activity for chemical fixation of CO2 under mild conditions.
4. Scorpionate-type coordination in MFU-4l metal-organic frameworks: small-molecule binding and activation upon the thermally activated formation of open metal sites.
Science.gov (United States)
Denysenko, Dmytro; Grzywa, Maciej; Jelic, Jelena; Reuter, Karsten; Volkmer, Dirk
2014-06-01
Postsynthetic metal and ligand exchange is a versatile approach towards functionalized MFU-4l frameworks. Upon thermal treatment of MFU-4l formates, coordinatively strongly unsaturated metal centers, such as zinc(II) hydride or copper(I) species, are generated selectively. Cu(I)-MFU-4l prepared in this way was stable under ambient conditions and showed fully reversible chemisorption of small molecules, such as O2, N2, and H2, with corresponding isosteric heats of adsorption of 53, 42, and 32 kJ mol(-1), respectively, as determined by gas-sorption measurements and confirmed by DFT calculations. Moreover, Cu(I)-MFU-4l formed stable complexes with C2H4 and CO. These complexes were characterized by FTIR spectroscopy. The demonstrated hydride transfer to electrophiles and strong binding of small gas molecules suggests these novel, yet robust, metal-organic frameworks with open metal sites as promising catalytic materials comprising earth-abundant metal elements.
5. STRUCTURE OF THE COMPLEX BETWEEN TRYPANOSOMAL TRIOSEPHOSPHATE ISOMERASE AND N-HYDROXY-4-PHOSPHONO-BUTANAMIDE - BINDING AT THE ACTIVE-SITE DESPITE AN OPEN FLEXIBLE LOOP CONFORMATION
NARCIS (Netherlands)
VERLINDE, CLMJ; WITMANS, CJ; PIJNING, T; KALK, KH; HOL, WGJ; CALLENS, M; OPPERDOES, FR
1992-01-01
The structure of triosephosphate isomerase from Trypanosoma brucei complexed with the competitive inhibitor N-hydroxy-4-phosphono-butanamide was determined by X-ray crystallography to a resolution of 2.84 angstrom. Full occupancy binding of the inhibitor is observed only at one of the active sites o
6. 49 CFR 325.77 - Computation of open site requirements-nonstandard sites.
Science.gov (United States)
2010-10-01
... site requirements—nonstandard sites. (a) If the distance between the microphone location point and the microphone target point is other than 50 feet (15.2 m), the test site must be an open site within a radius.... Figure 3 illustrates a test site which is larger than a standard test site and is based upon a...
7. Active Control of Open Cavities
Science.gov (United States)
UKeiley, Lawrence
2010-01-01
Open loop edge blowing was demonstrated as an effective method for reducing the broad band and tonal components of the fluctuating surface pressure in open cavities. Closed loop has been successfully applied to low Mach number open cavities. Need to push actuators that are viable for closed loop control in bandwidth and output. Need a better understanding of the effects of control on the flow through detailed measurements so better actuation strategies can be developed.
8. HOME Participating Jurisdictions Open Activities Reports
Data.gov (United States)
Department of Housing and Urban Development — This report is an MS Excel spreadsheet broken up by state. Participating Jurisdictions can use this report to view open activities in IDIS including activities with...
9. Landfills - OPEN_DUMPS_IDEM_IN: Open Dump Sites in Indiana (Indiana Department of Environmental Management, Point Shapefile)
Data.gov (United States)
NSGIC GIS Inventory (aka Ramona) — OPEN_DUMPS_IDEM_IN is a point shapefile that contains open dump site locations in Indiana, provided by personnel of Indiana Department of Environmental Management,...
10. Optimizing Ocean Space: Co-siting Open Ocean Aquaculture
Science.gov (United States)
Cobb, B. L.; Wickliffe, L. C.; Morris, J. A., Jr.
2016-12-01
In January of 2016, NOAA's National Marine Fisheries Service released the Gulf Aquaculture Plan (GAP) to manage the development of environmentally sound and economically sustainable open ocean finfish aquaculture in the Gulf of Mexico (inside the U.S. Exclusive Economic Zone [EEZ]). The GAP provides the first regulatory framework for aquaculture in federal waters with estimated production of 64 million pounds of finfish, and an estimated economic impact of \$264 million annually. The Gulf of Mexico is one of the most industrialized ocean basins in the world, with many existing ocean uses including oil and natural gas production, shipping and commerce, commercial fishing operations, and many protected areas to ensure conservation of valuable ecosystem resources and services. NOAA utilized spatial planning procedures and tools identifying suitable sites for establishing aquaculture through exclusion analyses using authoritative federal and state data housed in a centralized geodatabase. Through a highly collaborative, multi-agency effort a mock permitting exercise was conducted to illustrate the regulatory decision-making process for the Gulf. Further decision-making occurred through exploring co-siting opportunities with oil and natural gas platforms. Logistical co-siting was conducted to reduce overall operational costs by looking at distance to major port and commodity tonnage at each port. Importantly, the process of co-siting allows aquaculture to be coupled with other benefits, including the availability of previously established infrastructure and the reduction of environmental impacts.
11. Laparoscopic surgery compared with open surgery decreases surgical site infection in obese patients
DEFF Research Database (Denmark)
Shabanzadeh, Daniel M; Sørensen, Lars T
2012-01-01
: To compare surgical site infections rate in obese patients after laparoscopic surgery with open general abdominal surgery.......: To compare surgical site infections rate in obese patients after laparoscopic surgery with open general abdominal surgery....
12. Predicting success of oligomerized pool engineering (OPEN for zinc finger target site sequences
Directory of Open Access Journals (Sweden)
Goodwin Mathew J
2010-11-01
Full Text Available Abstract Background Precise and efficient methods for gene targeting are critical for detailed functional analysis of genomes and regulatory networks and for potentially improving the efficacy and safety of gene therapies. Oligomerized Pool ENgineering (OPEN is a recently developed method for engineering C2H2 zinc finger proteins (ZFPs designed to bind specific DNA sequences with high affinity and specificity in vivo. Because generation of ZFPs using OPEN requires considerable effort, a computational method for identifying the sites in any given gene that are most likely to be successfully targeted by this method is desirable. Results Analysis of the base composition of experimentally validated ZFP target sites identified important constraints on the DNA sequence space that can be effectively targeted using OPEN. Using alternate encodings to represent ZFP target sites, we implemented Naïve Bayes and Support Vector Machine classifiers capable of distinguishing "active" targets, i.e., ZFP binding sites that can be targeted with a high rate of success, from those that are "inactive" or poor targets for ZFPs generated using current OPEN technologies. When evaluated using leave-one-out cross-validation on a dataset of 135 experimentally validated ZFP target sites, the best Naïve Bayes classifier, designated ZiFOpT, achieved overall accuracy of 87% and specificity+ of 90%, with an ROC AUC of 0.89. When challenged with a completely independent test set of 140 newly validated ZFP target sites, ZiFOpT performance was comparable in terms of overall accuracy (88% and specificity+ (92%, but with reduced ROC AUC (0.77. Users can rank potentially active ZFP target sites using a confidence score derived from the posterior probability returned by ZiFOpT. Conclusion ZiFOpT, a machine learning classifier trained to identify DNA sequences amenable for targeting by OPEN-generated zinc finger arrays, can guide users to target sites that are most likely to function
13. Ab initio carbon capture in open-site metal-organic frameworks.
Science.gov (United States)
Dzubak, Allison L; Lin, Li-Chiang; Kim, Jihan; Swisher, Joseph A; Poloni, Roberta; Maximoff, Sergey N; Smit, Berend; Gagliardi, Laura
2012-10-01
During the formation of metal-organic frameworks (MOFs), metal centres can coordinate with the intended organic linkers, but also with solvent molecules. In this case, subsequent activation by removal of the solvent molecules creates unsaturated 'open' metal sites known to have a strong affinity for CO(2) molecules, but their interactions are still poorly understood. Common force fields typically underestimate by as much as two orders of magnitude the adsorption of CO(2) in open-site Mg-MOF-74, which has emerged as a promising MOF for CO(2) capture. Here we present a systematic procedure to generate force fields using high-level quantum chemical calculations. Monte Carlo simulations based on an ab initio force field generated for CO(2) in Mg-MOF-74 shed some light on the interpretation of thermodynamic data from flue gas in this material. The force field describes accurately the chemistry of the open metal sites, and is transferable to other structures. This approach may serve in molecular simulations in general and in the study of fluid-solid interactions.
14. OpenCL/OpenGL aproach for studying active Brownian motion
CERN Document Server
Żabicki, Michał A
2011-01-01
This work presents a methodology for studying active Brownian dynamics on ratchet potentials using interoperating OpenCL and OpenGL frameworks. Programing details along with optimization issues are discussed, followed by a comparison of performance on different devices. Time of visualization using OpenGL sharing buffer with OpenCL has been tested against another technique which, while using OpenGL, does not share memory buffer with OpenCL. Both methods has been compared with visualizing data to external software - gnuplot. OpenCL/OpenGL interoperating method has been found the most appropriate to visualize large set of data for which calculation itself is not very long.
15. Active Site Engineering in Electrocatalysis
DEFF Research Database (Denmark)
Verdaguer Casadevall, Arnau; Stephens, Ifan; Chorkendorff, Ib
on nanostructured electrodes.• Oxygen reduction to water has been carried out on Pt-rare earth alloys, which outperformed the activity of Pt by as much as a factor of five while showing promising stability. The increase in activity can be attributed to compressive strain of the Pt overlayer formed under reaction...... vacuum, as well as theory calculations. The thesis falls in three different parts: firstly, study of model systems for oxygen reduction to water; secondly, oxygen reduction to hydrogen peroxide on both model systems and commercially relevant nanoparticles and thirdly CO2 and CO electroreduction studies...
16. Ab initio carbon capture in open-site metal-organic frameworks
Science.gov (United States)
Dzubak, Allison L.; Lin, Li-Chiang; Kim, Jihan; Swisher, Joseph A.; Poloni, Roberta; Maximoff, Sergey N.; Smit, Berend; Gagliardi, Laura
2012-10-01
During the formation of metal-organic frameworks (MOFs), metal centres can coordinate with the intended organic linkers, but also with solvent molecules. In this case, subsequent activation by removal of the solvent molecules creates unsaturated ‘open’ metal sites known to have a strong affinity for CO2 molecules, but their interactions are still poorly understood. Common force fields typically underestimate by as much as two orders of magnitude the adsorption of CO2 in open-site Mg-MOF-74, which has emerged as a promising MOF for CO2 capture. Here we present a systematic procedure to generate force fields using high-level quantum chemical calculations. Monte Carlo simulations based on an ab initio force field generated for CO2 in Mg-MOF-74 shed some light on the interpretation of thermodynamic data from flue gas in this material. The force field describes accurately the chemistry of the open metal sites, and is transferable to other structures. This approach may serve in molecular simulations in general and in the study of fluid-solid interactions.
17. Knowledge related activities in open innovation
DEFF Research Database (Denmark)
Pedrosa, Alex; Välling, Margus; Boyd, Britta
2013-01-01
Theory and practice both have recognised the importance of external knowledge to enhance organisations’ innovation performance. Due to organisations’ growing interest in effectively collaborating with external knowledge sources, research has investigated the importance of firm-external stakeholder...... interaction in open innovation. Despite valuable insights into the importance of the variety of external knowledge sources to enhance (open) innovation, research has overlooked so far that managers’ characteristics and practices are relevant for the absorption of external knowledge in open innovation. Thus...... organisations. Our findings show that the exploration, transformation, and exploitation of external knowledge are associated with a distinct set of managers’ characteristics and practices that capture the dominant pattern of processing external knowledge in open innovation....
18. Opening of DNA double strands by helicases. Active versus passive opening
CERN Document Server
Betterton, M D
2002-01-01
Helicase opening of double-stranded nucleic acids may be "active" (the helicase directly destabilizes the dsNA to promote opening) or "passive" (the helicase binds ssNA available due to a thermal fluctuation which opens part of the dsNA). We describe helicase opening of dsNA, based on helicases which bind single NA strands and move towards the double-stranded region, using a discrete hopping'' model. The interaction between the helicase and the junction where the double strand opens is characterized by an interaction potential. The form of the potential determines whether the opening is active or passive. We calculate the rate of passive opening for the helicase PcrA, and show that the rate increases when the opening is active. Finally, we examine how to choose the interaction potential to optimize the rate of strand separation. One important result is our finding that active opening can increase the unwinding rate by 7 fold compared to passive opening.
19. Efficient oxygen electrocatalysis on special active sites
DEFF Research Database (Denmark)
Halck, Niels Bendtsen
throughout this thesis to understand these local structure effects and their influence on surface reactions. The concept of these special active sites is used to explain how oxygen evolution reaction (OER) catalysts can have activities beyond the limits of what was previously thought possible. The concept...
20. Active serine involved in the stabilization of the active site loop in the Humicola lanuginosa lipase
DEFF Research Database (Denmark)
Peters, Günther H.j.; Svendsen, A.; Langberg, H.;
1998-01-01
reveal that the hinges of the active site lid are more flexible in the wild-type Hll than in S146A. In contrast, larger fluctuations are observed in the middle region of the active site loop in S 146A than in Hll. These findings reveal that the single mutation (S146A) of the active site serine leads......We have investigated the binding properties of and dynamics in Humicola lanuginosa lipase (HII) and the inactive mutant S146A (active Ser146 substituted with Ala) using fluorescence spectroscopy and molecular dynamics simulations, respectively. Hll and S146A show significantly different binding......, whereas only small changes are observed for I-Ill suggesting that the active site Lid in the latter opens more easily and hence more lipase molecules are bound to the liposomes. These observations are in agreement with molecular dynamics simulations and subsequent essential dynamics analyses. The results...
1. Promoter proximal polyadenylation sites reduce transcription activity
DEFF Research Database (Denmark)
Andersen, Pia Kjølhede; Lykke-Andersen, Søren; Jensen, Torben Heick
2012-01-01
Gene expression relies on the functional communication between mRNA processing and transcription. We previously described the negative impact of a point-mutated splice donor (SD) site on transcription. Here we demonstrate that this mutation activates an upstream cryptic polyadenylation (CpA) site...... RNA polymerase II-transcribed genes use specialized termination mechanisms to maintain high transcription levels.......Gene expression relies on the functional communication between mRNA processing and transcription. We previously described the negative impact of a point-mutated splice donor (SD) site on transcription. Here we demonstrate that this mutation activates an upstream cryptic polyadenylation (CpA) site......, which in turn causes reduced transcription. Functional depletion of U1 snRNP in the context of the wild-type SD triggers the same CpA event accompanied by decreased RNA levels. Thus, in accordance with recent findings, U1 snRNP can shield premature pA sites. The negative impact of unshielded pA sites...
2. Soil contamination by brominated flame retardants in open waste dumping sites in Asian developing countries.
Science.gov (United States)
Eguchi, Akifimi; Isobe, Tomohiko; Ramu, Karri; Tue, Nguyen Minh; Sudaryanto, Agus; Devanathan, Gnanasekaran; Viet, Pham Hung; Tana, Rouch Seang; Takahashi, Shin; Subramanian, Annamalai; Tanabe, Shinsuke
2013-03-01
In Asian developing countries, large amounts of municipal wastes are dumped into open dumping sites each day without adequate management. This practice may cause several adverse environmental consequences and increase health risks to local communities. These dumping sites are contaminated with many chemicals including brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs). BFRs may be released into the environment through production processes and through the disposal of plastics and electronic wastes that contain them. The purpose of this study was to elucidate the status of BFR pollution in municipal waste dumping sites in Asian developing countries. Soil samples were collected from six open waste dumping sites and five reference sites in Cambodia, India, Indonesia, Malaysia, and Vietnam from 1999 to 2007. The results suggest that PBDEs are the dominant contaminants in the dumping sites in Asian developing countries, whereas HBCD contamination remains low. Concentrations of PBDEs and HBCDs ranged from ND to 180 μg/kg dry wt and ND to 1.4 μg/kg dry wt, respectively, in the reference sites and from 0.20 to 430 μg/kg dry wt and ND to 2.5 μg/kg dry wt, respectively, in the dumping sites. Contamination levels of PBDEs in Asian municipal dumping sites were comparable with those reported from electronic waste dismantling areas in Pearl River delta, China.
3. Understanding hydrogen adsorption in metal-organic frameworks with open metal sites: a computational study.
Science.gov (United States)
Yang, Qingyuan; Zhong, Chongli
2006-01-19
Recent experimental investigations show that the open metal sites may have a favorable impact on the hydrogen adsorption capacity of metal-organic frameworks (MOFs); however, no definite evidence has been obtained to date and little is known on the interactions between hydrogen and the pore walls of this kind of MOFs. In this work, a combined grand canonical Monte Carlo simulation and density functional theory calculation is performed on the adsorption of hydrogen in MOF-505, a recently synthesized MOF with open metal sites, to provide insight into molecular-level details of the underlying mechanisms. This work shows that metal-oxygen clusters are preferential adsorption sites for hydrogen, and the strongest adsorption of hydrogen is found in the directions of coordinatively unsaturated open metal sites, providing evidence that the open metal sites have a favorable impact on the hydrogen sorption capacity of MOFs. The storage capacity of hydrogen of MOF-505 at room temperature and moderate pressures is predicted to be low, in agreement with the outcome for hydrogen physisorption in other porous materials.
4. Open complex scrunching before nucleotide addition accounts for the unusual transcription start site of E. coli ribosomal RNA promoters.
Science.gov (United States)
Winkelman, Jared T; Chandrangsu, Pete; Ross, Wilma; Gourse, Richard L
2016-03-29
Most Escherichia coli promoters initiate transcription with a purine 7 or 8 nt downstream from the -10 hexamer, but some promoters, including the ribosomal RNA promoter rrnB P1, start 9 nt from the -10 element. We identified promoter and RNA polymerase determinants of this noncanonical rrnB P1 start site using biochemical and genetic approaches including mutational analysis of the promoter, Fe(2+) cleavage assays to monitor template strand positions near the active-site, and Bpa cross-linking to map the path of open complex DNA at amino acid and nucleotide resolution. We find that mutations in several promoter regions affect transcription start site (TSS) selection. In particular, we show that the absence of strong interactions between the discriminator region and σ region 1.2 and between the extended -10 element and σ region 3.0, identified previously as a determinant of proper regulation of rRNA promoters, is also required for the unusual TSS. We find that the DNA in the single-stranded transcription bubble of the rrnB P1 promoter complex expands and is "scrunched" into the active site channel of RNA polymerase, similar to the situation in initial transcribing complexes. However, in the rrnB P1 open complex, scrunching occurs before RNA synthesis begins. We find that the scrunched open complex exhibits reduced abortive product synthesis, suggesting that scrunching and unusual TSS selection contribute to the extraordinary transcriptional activity of rRNA promoters by increasing promoter escape, helping to offset the reduction in promoter activity that would result from the weak interactions with σ.
5. The complete structure of an activated open sodium channel
Science.gov (United States)
Sula, Altin; Booker, Jennifer; Ng, Leo C. T.; Naylor, Claire E.; DeCaen, Paul G.; Wallace, B. A.
2017-01-01
Voltage-gated sodium channels (Navs) play essential roles in excitable tissues, with their activation and opening resulting in the initial phase of the action potential. The cycling of Navs through open, closed and inactivated states, and their closely choreographed relationships with the activities of other ion channels lead to exquisite control of intracellular ion concentrations in both prokaryotes and eukaryotes. Here we present the 2.45 Å resolution crystal structure of the complete NavMs prokaryotic sodium channel in a fully open conformation. A canonical activated conformation of the voltage sensor S4 helix, an open selectivity filter leading to an open activation gate at the intracellular membrane surface and the intracellular C-terminal domain are visible in the structure. It includes a heretofore unseen interaction motif between W77 of S3, the S4–S5 interdomain linker, and the C-terminus, which is associated with regulation of opening and closing of the intracellular gate. PMID:28205548
6. French Customs office - Prévessin site: New opening times
CERN Multimedia
Relations with the Host States Service
2005-01-01
Please note the following new opening times for CERN's on-site French Customs office (Building 904): From Monday to Thursday: 8:15 - 12:15 / 13:30 - 17:30 Fridays: 8:15 - 12:15 / 13:30 - 16:00 The new opening times will apply as of 1 March 2005. For further information, please call 75618 or send an e-mail to [email protected] Relations with the Host States Service http://www.cern.ch/relations/ Tel. 72848
7. Open active cloaking and illusion devices for the Laplace equation
Science.gov (United States)
Ma, Qian; Yang, Fan; Jin, Tian Yu; Lei Mei, Zhong; Cui, Tie Jun
2016-04-01
We propose open active cloaking and illusion devices for the Laplace equation. Compared with the closed configurations of active cloaking and illusion devices, we focus on improving the distribution schemes for the controlled sources, which do not have to surround the protected object strictly. Instead, the controlled sources can be placed in several small discrete clusters, and produce the desired voltages along the controlled boundary, to actively hide or disguise the protected object. Numerical simulations are performed with satisfactory results, which are further validated by experimental measurements. The open cloaking and illusion devices have many advantages over the closed configurations in various potential applications.
8. Characterization and pollution potential assessment of Tunceli, Turkey municipal solid waste open dumping site leachates.
Science.gov (United States)
Demirbilek, Deniz; Öztüfekçi Önal, Ayten; Demir, Veysel; Uslu, Gulsad; Arslanoglu-Isık, Hilal
2013-11-01
Environmental monitoring of leachate quality from an open municipal solid waste dumping site in Tunceli, Turkey was studied in this research. The most commonly examined pollution parameters were determined on a seasonal basis. The annual average 5-day biological oxygen demand (BOD₅) and chemical oxygen demand (COD) values of station points were measured as 70 and 425 mg/L, respectively, and also the average BOD₅/COD ratio (a measure of biodegradability) was calculated as 0.20. The low ratio of biodegradability and slightly alkaline pH values in the leachate samples indicated that the site was characterized by methanogenic conditions. The mean ammonium-nitrogen (NH4 (+)-N) and corresponding phosphate (orthophosphate) values were assayed as 70 and 11 mg/L, respectively. The average solids content in the leachates was measured as 4,681 mg/L (total solids) and 144 mg/L (suspended solids). Very low concentrations of iron, manganese, copper, and zinc in the leachate samples were found and the concentration of cadmium was measured below detection limits. Excessive amount of nutrients and high organic and inorganic pollutant content in the leachates pose serious pollution potential to the environment. Since no drainage system or bio treatment exists in this open dumping site, high permeability of natural soil at the site and in the surrounding area and very fractured and crackled rocks under natural soil are indicators of high groundwater pollution potential in this site.
9. The role of open lead interactions in atmospheric ozone variability between Arctic coastal and inland sites
Directory of Open Access Journals (Sweden)
Peter K. Peterson
2016-05-01
Full Text Available Abstract Boundary layer atmospheric ozone depletion events (ODEs are commonly observed across polar sea ice regions following polar sunrise. During March-April 2005 in Alaska, the coastal site of Barrow and inland site of Atqasuk experienced ODEs (O3 < 10 nmol mol-1 concurrently for 31% of the observations, consistent with large spatial scale ozone depletion. However, 7% of the time ODEs were exclusively observed inland at Atqasuk. This phenomenon also occurred during one of nine flights during the BRomine, Ozone, and Mercury EXperiment (BROMEX, when atmospheric vertical profiles at both sites showed near-surface ozone depletion only at Atqasuk on 28 March 2012. Concurrent in-flight BrO measurements made using nadir scanning differential optical absorption spectroscopy (DOAS showed the differences in ozone vertical profiles at these two sites could not be attributed to differences in locally occurring halogen chemistry. During both studies, backward air mass trajectories showed that the Barrow air masses observed had interacted with open sea ice leads, causing increased vertical mixing and recovery of ozone at Barrow and not Atqasuk, where the air masses only interacted with tundra and consolidated sea ice. These observations suggest that, while it is typical for coastal and inland sites to have similar ozone conditions, open leads may cause heterogeneity in the chemical composition of the springtime Arctic boundary layer over coastal and inland areas adjacent to sea ice regions.
10. Closure of the tunnel linking the CERN sites | Exceptional opening of Gate E
CERN Multimedia
GS-IS
2013-01-01
The tunnel linking the CERN sites will be closed to traffic from 19 to 26 July inclusive for the installation of an access system using number-plate recognition. During this period, Gate E will be open, exceptionally, in both directions from Monday until Friday from 7.00 a.m. to 7.00 p.m. under the same access conditions as for the tunnel linking the CERN sites, laid down in the following document: http://hoststates.web.cern.ch/hoststates/documents/8200980415.pdf.
11. Probing the putative active site of YjdL
DEFF Research Database (Denmark)
Jensen, Johanne Mørch; Ismat, Fouzia; Szakonyi, Gerda;
2012-01-01
YjdL from E. coli is an unusual proton-coupled oligopeptide transporter (POT). Unlike prototypical POTs, dipeptides are preferred over tripeptides, in particular dipeptides with a positively charged C-terminal residue. To further understand this difference in peptide specificity, the sequences...... of YjdL and YdgR, a prototypical E. coli POT, were compared in light of the crystal structure of a POT from Shewanella oneidensis. Several residues found in the putative active site were mutated and the activities of the mutated variants were assessed in terms of substrate uptake assays, and changes...... pocket that opens towards the extracellular space. The C-terminal side chain faces in the opposite direction into a sub pocket that faces the cytoplasm. These data indicated a stabilizing effect on a bulky N-terminal residue by an Ala281Phe variant and on the dipeptide backbone by Trp278...
12. Open Systems of Environmental Decision-Making the Mrs Nuclear Waste Siting Case in Tennessee
Science.gov (United States)
McCabe, Amy Snyder
Decision making in the science and technology policy domain has traditionally been an exclusive enterprise, with scientific and technical elites working within the confines of the administrative state to create public policy. Policies generated from this type of decision making process have been perceived by the public as unsuccessful, so much so that this sort of closed system is gradually being replaced by a more open one in which citizens and subnational governments play a significantly larger role in the formation of technical policy. This study is concerned with, within the context of the emerging open system of administrative decision making, how America's public sector is handling the challenge of implementing an environmental policy which commands technical expertise--managing the nation's highly-radioactive nuclear waste. How can a modern democratic system adapt to greater participation in a complex policy area once monopolized by a small cadre of technical specialists, and what are the implications for public managers of a more open system?. These questions lead to the application of a model of science and technology policy to a case study tracing the attempted siting by the U.S. Department of Energy in 1985 of a monitored retrievable storage facility in Tennessee. Extensive personal interviews with key actors at the local, state, and national levels, as well as a review of agency files and relevant documents comprise the data base. A systematic examination of the Tennessee case finds that a more open system of decision making does not alone guarantee successful implementation of science and technology policy, but can be useful provided that the process is truly open. The analysis suggests that more open decision making is likely to affect the performance of public managers charged with implementing technical policies. The responsibility of defining the parameters of open systems remains with the Congress.
13. Predictors of surgical site infection in laparoscopic and open ventral incisional herniorrhaphy.
Science.gov (United States)
Kaafarani, Haytham M A; Kaufman, Derrick; Reda, Domenic; Itani, Kamal M F
2010-10-01
Surgical site infection (SSI) after ventral incisional hernia repair (VIH) can result in serious consequences. We sought to identify patient, procedure, and/or hernia characteristics that are associated with SSI in VIH. Between 2004 and 2006, patients were randomized in four Veteran Affairs (VA) hospitals to undergo laparoscopic or open VIH. Patients who developed SSI within eight weeks postoperatively were compared to those who did not. A bivariate analysis for each factor and a multiple logistic regression analysis were performed to determine factors associated with SSI. The variables studied included patient characteristics and co-morbidities (e.g., age, gender, race, ethnicity, body mass index, ASA classification, diabetes, steroid use), hernia characteristics (e.g., size, duration, number of previous incisions), procedure characteristics (e.g., open versus laparoscopic, blood loss, use of postoperative drains, operating room temperature) and surgeons' experience (resident training level, number of open VIH previously performed by the attending surgeon). Antibiotic prophylaxis, anticoagulation protocols, preparation of the skin, draping of the wound, body temperature control, and closure of the surgical site were all standardized and monitored throughout the study period. Out of 145 patients who underwent VIH, 21 developed a SSI (14.5%). Patients who underwent open VIH had significantly more SSIs than those who underwent laparoscopic VIH (22.1% versus 3.4%; P = 0.002). Among patients who underwent open VIH, those who developed SSI had a recorded intraoperative blood loss greater than 25 mL (68.4% versus 40.3%; P = 0.030), were more likely to have a drain placed (79.0% versus 49.3%; P = 0.021) and were more likey to be operated on by surgeons with less than 75 open VIH case experience (52.6% versus 28.4%; P = 0.048). Patient and hernia characteristics were similar between the two groups. In a multiple logistic regression analysis, the open surgical technique was
14. The thermal stability of the framework, hydroxyl groups, and active sites of faujasites
Energy Technology Data Exchange (ETDEWEB)
Mishin, I.V.; Kalinin, V.P.; Nissenbaum, V.D. [Zelinskii Institute of Organic Chemistry, Moscow (Russian Federation); Beyer, H.K. [Hungarian Academy of Sciences, Budapest (Hungary); Karge, H.G. [Fritz Haber Institute of the Max Planck Soceity, Berlin (Germany)
1994-07-01
The effect of the framework composition on the crystallinity and {open_quotes}density{close_quotes} of hydroxyl groups and the concentration of active sites is reported for hydrogen forms of Y zeolites preheated at 400 - 1000{degrees}C. The increase in the Si/Al ratios results in improved resistance of the framework atoms and hydroxyl groups to high temperatures and in enhanced thermal stability of the sites that are active in the cracking of isooctane and disproportionation of ethylbenzene.
15. Learning, Learning Analytics, Activity Visualisation and Open learner Model
DEFF Research Database (Denmark)
Bull, Susan; Kickmeier-Rust, Michael; Vatrapu, Ravi
2013-01-01
This paper draws on visualisation approaches in learning analytics, considering how classroom visualisations can come together in practice. We suggest an open learner model in situations where many tools and activity visualisations produce more visual information than can be readily interpreted....
16. Open systems of environmental decision making: the MRS nuclear-waste siting case in Tennessee
Energy Technology Data Exchange (ETDEWEB)
McCabe, A.S.
1987-01-01
This study is concerned with, within the context of the emerging open system of administrative decision making, how America's public sector is handling the challenge of implementing an environmental policy that commands technical expertise - managing the nation's highly-radioactive nuclear waste. How can a modern democratic system adapt to greater participation in a complex policy area once monopolized by a small cadre of technical specialists, and what are the implications for public managers of a more open system. These questions lead to the application of a model of science and technology policy to a case study tracing the attempted siting by the US Department of Energy in 1985 of a monitored retrievable storage facility in Tennessee. Extensive personal interviews with key actors at the local, state, and national levels, as well as a review of agency files and relevant documents comprise the data base. A systematic examination of the Tennessee case finds that a more-open system of decision making does not alone guarantee successful implementation of science and technology policy, but can be useful provided that the process is truly open.
17. OC ToGo: bed site image integration into OpenClinica with mobile devices
Science.gov (United States)
Haak, Daniel; Gehlen, Johan; Jonas, Stephan; Deserno, Thomas M.
2014-03-01
Imaging and image-based measurements nowadays play an essential role in controlled clinical trials, but electronic data capture (EDC) systems insufficiently support integration of captured images by mobile devices (e.g. smartphones and tablets). The web application OpenClinica has established as one of the world's leading EDC systems and is used to collect, manage and store data of clinical trials in electronic case report forms (eCRFs). In this paper, we present a mobile application for instantaneous integration of images into OpenClinica directly during examination on patient's bed site. The communication between the Android application and OpenClinica is based on the simple object access protocol (SOAP) and representational state transfer (REST) web services for metadata, and secure file transfer protocol (SFTP) for image transfer, respectively. OpenClinica's web services are used to query context information (e.g. existing studies, events and subjects) and to import data into the eCRF, as well as export of eCRF metadata and structural information. A stable image transfer is ensured and progress information (e.g. remaining time) visualized to the user. The workflow is demonstrated for a European multi-center registry, where patients with calciphylaxis disease are included. Our approach improves the EDC workflow, saves time, and reduces costs. Furthermore, data privacy is enhanced, since storage of private health data on the imaging devices becomes obsolete.
18. Perchlorate Reductase Is Distinguished by Active Site Aromatic Gate Residues.
Science.gov (United States)
Youngblut, Matthew D; Tsai, Chi-Lin; Clark, Iain C; Carlson, Hans K; Maglaqui, Adrian P; Gau-Pan, Phonchien S; Redford, Steven A; Wong, Alan; Tainer, John A; Coates, John D
2016-04-22
Perchlorate is an important ion on both Earth and Mars. Perchlorate reductase (PcrAB), a specialized member of the dimethylsulfoxide reductase superfamily, catalyzes the first step of microbial perchlorate respiration, but little is known about the biochemistry, specificity, structure, and mechanism of PcrAB. Here we characterize the biophysics and phylogeny of this enzyme and report the 1.86-Å resolution PcrAB complex crystal structure. Biochemical analysis revealed a relatively high perchlorate affinity (Km = 6 μm) and a characteristic substrate inhibition compared with the highly similar respiratory nitrate reductase NarGHI, which has a relatively much lower affinity for perchlorate (Km = 1.1 mm) and no substrate inhibition. Structural analysis of oxidized and reduced PcrAB with and without the substrate analog SeO3 (2-) bound to the active site identified key residues in the positively charged and funnel-shaped substrate access tunnel that gated substrate entrance and product release while trapping transiently produced chlorate. The structures suggest gating was associated with shifts of a Phe residue between open and closed conformations plus an Asp residue carboxylate shift between monodentate and bidentate coordination to the active site molybdenum atom. Taken together, structural and mutational analyses of gate residues suggest key roles of these gate residues for substrate entrance and product release. Our combined results provide the first detailed structural insight into the mechanism of biological perchlorate reduction, a critical component of the chlorine redox cycle on Earth.
19. The Transcription Bubble of the RNA Polymerase-Promoter Open Complex Exhibits Conformational Heterogeneity and Millisecond-Scale Dynamics : Implications for Transcription Start-Site Selection
NARCIS (Netherlands)
Robb, Nicole C.; Cordes, Thorben; Hwang, Ling Chin; Gryte, Kristofer; Duchi, Diego; Craggs, Timothy D.; Santoso, Yusdi; Weiss, Shimon; Ebright, Richard H.; Kapanidis, Achillefs N.
2013-01-01
Bacterial transcription is initiated after RNA polymerase (RNAP) binds to promoter DNA, melts similar to 14 bp around the transcription start site and forms a single-stranded "transcription bubble" within a catalytically active RNAP-DNA open complex (RPo). There is significant flexibility in the tra
20. Developing an open-access antimicrobial resistance learning site for veterinary medical students.
Science.gov (United States)
Gordoncillo, Mary Joy N; Bender, Jeff; Noffsinger, Jason; Bartlett, Paul C
2011-01-01
Recognizing the crucial role of veterinarians in mitigating antimicrobial resistance (AMR), the Centers for Disease Control and Prevention (CDC) has funded the development of a suite of educational materials to promote the responsible veterinary medical use of antimicrobials. An open-access, Web-based multimedia curriculum regarding antimicrobial resistance in veterinary practice was thus created. The antimicrobial-resistance learning site (AMRLS) for veterinary medical students was completed and made available for use in January 2011 (http://amrls.cvm.msu.edu/). Designed for integration into existing veterinary medical courses, the AMRLS is also a resource for continuing education for practicing veterinarians, animal scientists, and food-animal industry specialists. This Web site emphasizes the mechanisms by which AMR emerges and spreads, the significant role of veterinarians in mitigating AMR, and the need to preserve the efficacy of antibiotics for future generations.
1. Sustainable Sites Initiative: US updated rating criteria for open spaces design
Directory of Open Access Journals (Sweden)
Renata Valente
2014-10-01
Full Text Available The paper presents the U.S. Sustainable Sites Initiative, by illustrating and commenting the recent updates of the rating criteria in addition to a number of certified projects, including some sites visited by the author in California. The system is compared with existing tools, as LEED 2009 for Neighborhood Development Rating System, albeit some differences also in scale of interventions. In the work, scientific literature and personal considerations are given about those aspects still not evaluated by the system and its potential wider applicability with regard to directions of research on the topic. The theme fits well in the mainstream of studies dedicated to the design of resilient open spaces, contributing to adaptation and mitigation of climate change.
2. Landscapes, depositional environments and human occupation at Middle Paleolithic open-air sites in the southern Levant, with new insights from Nesher Ramla, Israel
Science.gov (United States)
Zaidner, Yossi; Frumkin, Amos; Friesem, David; Tsatskin, Alexander; Shahack-Gross, Ruth
2016-04-01
Middle Paleolithic human occupation in the Levant (250-50 ka ago) has been recorded in roofed (cave and rockshelter) and open-air sites. Research at these different types of sites yielded different perspectives on the Middle Paleolithic human behavior and evolution. Until recently, open-air Middle Paleolithic sites in the Levant were found in three major sedimentary environments: fluvial, lake-margin and spring. Here we describe a unique depositional environment and formation processes at the recently discovered open-air site of Nesher Ramla (Israel) and discuss their contribution to understanding site formation processes in open-air sites in the Levant. The site is 8-m-thick Middle Paleolithic sequence (OSL dated to 170-80 ka) that is located in a karst sinkhole formed by gravitational deformation and sagging into underground voids. The sedimentary sequence was shaped by gravitational collapse, cyclic colluviation of soil and gravel into the depression, waterlogging, in situ pedogenesis and human occupation. Original bedding and combustion features are well-preserved in the Lower archaeological sequence, a rare occurrence in comparison to other open-air archaeological sites. This phenomenon coincides with episodes of fast sedimentation/burial, which also allowed better preservation of microscopic remains such as ash. The Upper archaeological sequence does not exhibit bedding or preservation of ash, despite presence of heat-affected lithic artifacts, which makes it similar to other open-air sites in the Levant. We suggest that rate of burial is the major factor that caused the difference between the Upper and Lower sequences. The differences in the burial rate may be connected to environmental and vegetation changes at the end of MIS 6. We also identified an interplay between sediment in-wash and density of human activity remains, i.e. during episodes of low natural sediment input the density of artifacts is higher relative to episodes with high rate of sediment in
3. Clostripain: Characterization of the active site
National Research Council Canada - National Science Library
Kembhavi, Ashu A; Buttle, David J; Rauber, Peter; Barrett, Alan J
1991-01-01
... + for stability and activity. Mg 2+ and Sr 2+ were ineffective. Rapid inactivation by diethylpyrocarbonate, reversed by hydroxylamine, indicated that histidine is essential for catalytic activity...
4. Multi-site campaign on the open cluster M67. I. Observations and photometric reductions
CERN Document Server
Stello, D; Bedding, T R; Bouzid, M Y; Bruntt, H; Csubry, Z; Dind, Z E; Frandsen, S; Gilliland, R L; Jacob, A P; Jensen, H R; Kang, Y B; Kim, S L; Kiss, L L; Kjeldsen, H; Koo, J R; Lee, J A; Lee, C U; Nuspl, J; Sterken, C; Szabó, R
2006-01-01
We report on an ambitious multi-site campaign aimed at detecting stellar variability, particularly solar-like oscillations, in the red giant stars in the open cluster M67 (NGC 2682). During the six-week observing run, which comprised 164 telescope nights, we used nine 0.6-m to 2.1-m class telescopes located around the world to obtain uninterrupted time-series photometry. We outline here the data acquisition and reduction, with emphasis on the optimisation of the signal-to-noise of the low amplitude (50-500 micromag) solar-like oscillations. This includes a new and efficient method for obtaining the linearity profile of the CCD response at ultra high precision (~10 parts per million). The noise in the final time series is 0.50 mmag per minute integration for the best site, while the noise in the Fourier spectrum of all sites combined is 20 micromag. In addition to the red giant stars, this data set proves to be very valuable for studying high-amplitude variable stars such as eclipsing binaries, W UMa systems a...
5. Open sesame: IDC launches Internet site to access well logs, other data
Energy Technology Data Exchange (ETDEWEB)
Marsters, S.
2001-06-01
International Datashare Corporation has recently opened a new website - www.EnerGISite.com - to make it possible for geologists and geophysicists to access its vast store of Canadian well logs. The well logs have been reproduced over the years in a variety of forms: microfiche, half-scale prints and film, and full-scale prints and film. More recently, IDC has digitized a large number of logs and captured the images in raster form (i.e. scanned, not digitized). The digital and raster logs will, henceforth, be accessible in the EnerGISite through a GIS map front end. When users log on to the site, a picture of world will appear. Clicking on the Canadian landmass, the database will the tell the user what data is available. By zooming in on a particular area of the map such as for example Alberta, all well locations will be shown. By selecting individual wells, users can find out if raster and digital curves exist. Individual logs can be purchased on a transactional basis. Companies can also subscribe for unlimited usage. Logs will be sent by e-mail, or downloaded directly into a user-created file. U.S. data is expected to be launched in July 2001, with selected areas of the world added at a later date. Production data for a site will be provided by International Petrodata Limited, a business partner of IDC. New datasets and software tools to the site are planned by IDC over time.
6. Radio Astronomy Demonstrator: Assessment of the Appropriate Sites through a GIS Open Source Application
Directory of Open Access Journals (Sweden)
Lia Duarte
2016-11-01
Full Text Available In the framework of Portuguese radio astronomical capacitation towards participation in the Square Kilometer Array (SKA project, a site was selected for radio astronomical testing purposes and the development of a radio astronomical infrastructure. The site is within Herdade da Contenda (HC, a large national forest perimeter, located in Alentejo (Portugal. In order to minimize the impacts in the ecosystem and landscape, an application based on the Geographic Information System (GIS open source environment was created, the HC Environmental Integrated Management System. This application combines several functionalities and menus with different characterization methods allowing the creation of multiple maps regarding the HC characteristics, such as Digital Elevation Model (DEM, Land Use Land Cover (LULC, Normalized Difference Vegetation Index (NDVI, groundwater vulnerability, erosion risk, flood risk and forest fire risk. Other geographical information can be added if necessary (human heritage visualization and fauna and flora. A decision making support tool was also developed. It incorporates an algorithm running through a series of assigned weights and eliminatory factors to find the locations best suited for the infrastructure with minimal impact to the local ecosystem. In order to test the application and the decision making tool, several maps were used as input in order to decide which sites are more adequate. The application developed can be adopted for other protected or natural areas.
7. An ActiveX Control Based on OpenGL%基于OpenGL的ActiveX控件的实现
Institute of Scientific and Technical Information of China (English)
杨日容; 杨承志; 杨晓洪
2005-01-01
ActiveX控件是当前开发各种应用程序的一项重要技术,是一种能与其它程序交互通信的程序体系结构.OpenGL则是一种功能强大的三维图形开发工具,利用OpenGL可以生成真彩的三维动态场景.文章在介绍OpenGL及ActiveX控件技术的基础上详细介绍了在Visual C++6.0的环境下开发基于OpenGL的三维动画的方法,并把它封装为ActiveX控件,最后把该控件应用到常用的演示文稿制作软件Powerpoint2000中,实现了在幻灯片中三维动画的显示与控制.
8. Crystallographic B factor of critical residues at enzyme active site
Institute of Scientific and Technical Information of China (English)
张海龙; 宋时英; 林政炯
1999-01-01
Thirty-seven sets of crystallographic enzyme data were selected from Protein Data Bank (PDB, 1995). The average temperature factors (B) of the critical residues at the active site and the whole molecule of those enzymes were calculated respectively. The statistical results showed that the critical residues at the active site of most of the enzymes had lower B factors than did the whole molecules, indicating that in the crystalline state the critical residues at the active site of the natural enzymes possess more stable conformation than do the whole molecules. The flexibility of the active site during the unfolding by denaturing was also discussed.
9. Evapotranspiration from marsh and open-water sites at Upper Klamath Lake, Oregon, 2008--2010
Science.gov (United States)
Stannard, David I.; Gannett, Marshall W.; Polette, Danial J.; Cameron, Jason M.; Waibel, M. Scott; Spears, J. Mark
2013-01-01
Water allocation in the Upper Klamath Basin has become difficult in recent years due to the increase in occurrence of drought coupled with continued high water demand. Upper Klamath Lake is a central component of water distribution, supplying water downstream to the Klamath River, supplying water for irrigation diversions, and providing habitat for various species within the lake and surrounding wetlands. Evapotranspiration (ET) is a major component of the hydrologic budget of the lake and wetlands, and yet estimates of ET have been elusive—quantified only as part of a lumped term including other substantial water-budget components. To improve understanding of ET losses from the lake and wetlands, measurements of ET were made from May 2008 through September 2010. The eddy-covariance method was used to monitor ET at two wetland sites continuously during this study period and the Bowen-ratio energy-balance method was used to monitor open-water lake evaporation at two sites during the warmer months of the 3 study years. Vegetation at one wetland site (the bulrush site) consists of a virtual monoculture of hardstem bulrush (formerly Scirpus acutus, now Schoenoplectus acutus), and at the other site (the mixed site) consists of a mix of about 70 percent bulrush, 15 percent cattail (Typha latifolia), and 15 percent wocus (Nuphar polysepalum). Measured ET at these two sites was very similar (means were ±2.5 percent) and mean wetland ET is computed as a 70 to 30 percent weighted average of the bulrush and mixed sites, respectively, based on community-type distribution estimated from satellite imagery. Biweekly means of wetland ET typically vary from maximum values of around 6 to 7 millimeters per day during midsummer, to minimum values of less than 1 mm/d during midwinter. This strong annual signal primarily reflects life-cycle changes in the wetland vegetation, and the annual variation of radiative input to the surface and resulting temperature. The perennial vegetation
10. A microporous Zn(II)-MOF with open metal sites: structure and selective adsorption properties.
Science.gov (United States)
Zheng, Xiaofang; Huang, Yumei; Duan, Jingui; Wang, Chenggang; Wen, Lili; Zhao, Jinbo; Li, Dongfeng
2014-06-14
A three-dimensional microporous framework, Zn(II)-MOF [Zn(HPyImDC)(DMA)]n (1) (H3PyImDC = 2-(pyridine-4-yl)-1H-4,5-imidazoledicarboxylic, DMA = N,N'-dimethylacetamide), with open metal sites and small-sized pores, exhibits excellent selective capture of CO2 over N2 and CH4 at 273 K, as well as alcohols from water. The excellent CO2 adsorption selectivity of 1 allows its potential use in the capture of CO2 from industrial flue gas or the removal of CO2 from natural gas. More interestingly, compound represents the rare case of porous materials separating propanol isomers, which may be caused by the relative flexibility of the linear n-propanol considering that both n-propanol and i-propanol have similar kinetic diameters.
11. Optimizing Open Iron Sites in Metal-Organic Frameworks for Ethane Oxidation: A First-Principles Study.
Science.gov (United States)
Liao, Peilin; Getman, Rachel B; Snurr, Randall Q
2017-04-10
Activation of the C-H bonds in ethane to form ethanol is a highly desirable, yet challenging, reaction. Metal-organic frameworks (MOFs) with open Fe sites are promising candidates for catalyzing this reaction. One advantage of MOFs is their modular construction from inorganic nodes and organic linkers, allowing for flexible design and detailed control of properties. In this work, we studied a series of single-metal atom Fe model systems with ligands that are commonly used as MOF linkers and tried to understand how one can design an optimal Fe catalyst. We found linear relationships between the binding enthalpy of oxygen to the Fe sites and common descriptors for catalytic reactions, such as the Fe 3d energy levels in different reaction intermediates. We further analyzed the three highest-barrier steps in the ethane oxidation cycle (including desorption of the product) with the Fe 3d energy levels. Volcano relationships are revealed with peaks toward higher Fe 3d energy and stronger electron-donating group functionalization of linkers. Furthermore, we found that the Fe 3d energy levels positively correlate with the electron-donating strength of functional groups on the linkers. Finally, we validated our hypotheses on larger models of MOF-74 iron sites. Compared with MOF-74, functionalizing the MOF-74 linkers with NH2 groups lowers the enthalpic barrier for the most endothermic step in the reaction cycle. Our findings provide insight for catalyst optimization and point out directions for future experimental efforts.
12. Archaeological horizons and fluvial processes at the Lower Paleolithic open-air site of Revadim (Israel).
Science.gov (United States)
Marder, Ofer; Malinsky-Buller, Ariel; Shahack-Gross, Ruth; Ackermann, Oren; Ayalon, Avner; Bar-Matthews, Miryam; Goldsmith, Yonaton; Inbar, Moshe; Rabinovich, Rivka; Hovers, Erella
2011-04-01
In this paper we present new data pertaining to the paleo-landscape characteristics at the Acheulian site of Revadim, on the southern coastal plain of Israel. Sedimentological, isotopic, granulometric and micromorphological studies showed that the archaeological remains accumulated in an active fluvial environment where channel action, overbank flooding and episodic inundation occurred. Measurements of total organic matter and its carbon isotopic composition indicate that the hominin activity at the site started at a period of relatively drier conditions, which coincided with erosion of the preceding soil sequence. This process led to the formation of a gently-undulating topography, as reconstructed by a GIS model. Later deposition documents relatively wetter conditions, as indicated by carbon isotopic composition. Formation processes identified at the site include fluvial processes, inundation episodes that resulted in anaerobic conditions and formation of oxide nodules, as well as small-scale bioturbation and later infiltration of carbonate-rich solutions that resulted in the formation of calcite nodules and crusts. The combination of micro-habitats created favorable conditions that repeatedly drew hominins to the area, as seen by a series of super-imposed archaeological horizons. This study shows that site-specific paleo-landscape reconstructions should play an important role in understanding regional variation among hominin occupations and in extrapolating long-term behavioral patterns during the Middle Pleistocene.
13. Savannah River Site prioritization of transition activities
Energy Technology Data Exchange (ETDEWEB)
Finley, R.H.
1993-11-01
Effective management of SRS conversion from primarily a production facility to other missions (or Decontamination and Decommissioning (D&D)) requires a systematic and consistent method of prioritizing the transition activities. This report discusses the design of a prioritizing method developed to achieve systematic and consistent methods of prioritizing these activities.
14. OPEN SPATIAL DECISION SUPPORT SYSTEM: CASE FOR RADIOACTIVE WASTE DISPOSAL SITE SELECTION
Directory of Open Access Journals (Sweden)
Dario Perković
2012-07-01
Full Text Available In recent years the scientific and professional circles frequently discussed about radioactive waste and site selection for radioactive waste disposal. This issue will be further updated with accession of Republic of Croatia to the European Union and the only issue is politicized view of the fact that nuclear power plant Krško Croatia shares with neighbouring Republic of Slovenia. All the necessary studies have been made and these are attended by experts from different areas. Also, all Croatian residents should be familiar with this subject matter in a manner accessible to the general public through all available media. There are some questions: What are the institutions have taken on the issue of informing the public and can it be enough? When selecting a suitable site, with many parameters, the basic element is suitable geological formation, although the landfill must be socially acceptable. Well established methods used in the selection of eligible areas are multicriteria decision analysis (MCDA, geographic information system (GIS and combined GIS-MCDA method. The application of these methods is of great help in making decisions about the location of disposal of radioactive waste. Presentation of results, designed in the form of an open spatial decision support system, could help in education and informing the general public (the paper is published in Croatian.
15. Predicting active site residue annotations in the Pfam database
Directory of Open Access Journals (Sweden)
Finn Robert D
2007-08-01
Full Text Available Abstract Background Approximately 5% of Pfam families are enzymatic, but only a small fraction of the sequences within these families ( Description We have created a large database of predicted active site residues. On comparing our active site predictions to those found in UniProtKB, Catalytic Site Atlas, PROSITE and MEROPS we find that we make many novel predictions. On investigating the small subset of predictions made by these databases that are not predicted by us, we found these sequences did not meet our strict criteria for prediction. We assessed the sensitivity and specificity of our methodology and estimate that only 3% of our predicted sequences are false positives. Conclusion We have predicted 606110 active site residues, of which 94% are not found in UniProtKB, and have increased the active site annotations in Pfam by more than 200 fold. Although implemented for Pfam, the tool we have developed for transferring the data can be applied to any alignment with associated experimental active site data and is available for download. Our active site predictions are re-calculated at each Pfam release to ensure they are comprehensive and up to date. They provide one of the largest available databases of active site annotation.
16. Diffusional correlations among multiple active sites in a single enzyme.
Science.gov (United States)
Echeverria, Carlos; Kapral, Raymond
2014-04-07
Simulations of the enzymatic dynamics of a model enzyme containing multiple substrate binding sites indicate the existence of diffusional correlations in the chemical reactivity of the active sites. A coarse-grain, particle-based, mesoscopic description of the system, comprising the enzyme, the substrate, the product and solvent, is constructed to study these effects. The reactive and non-reactive dynamics is followed using a hybrid scheme that combines molecular dynamics for the enzyme, substrate and product molecules with multiparticle collision dynamics for the solvent. It is found that the reactivity of an individual active site in the multiple-active-site enzyme is reduced substantially, and this effect is analyzed and attributed to diffusive competition for the substrate among the different active sites in the enzyme.
17. Perspective: On the active site model in computational catalyst screening
Science.gov (United States)
Reuter, Karsten; Plaisance, Craig P.; Oberhofer, Harald; Andersen, Mie
2017-01-01
First-principles screening approaches exploiting energy trends in surface adsorption represent an unparalleled success story in recent computational catalysis research. Here we argue that our still limited understanding of the structure of active sites is one of the major bottlenecks towards an ever extended and reliable use of such computational screening for catalyst discovery. For low-index transition metal surfaces, the prevalently chosen high-symmetry (terrace and step) sites offered by the nominal bulk-truncated crystal lattice might be justified. For more complex surfaces and composite catalyst materials, computational screening studies will need to actively embrace a considerable uncertainty with respect to what truly are the active sites. By systematically exploring the space of possible active site motifs, such studies might eventually contribute towards a targeted design of optimized sites in future catalysts.
18. Characterization of Site for Installing Open Loop Ground Source Heat Pump System
Science.gov (United States)
Yun, S. W.; Park, Y.; Lee, J. Y.; Yi, M. J.; Cha, J. H.
2014-12-01
This study was conducted to understand hydrogeological properties of site where open loop ground source heat pump system will be installed and operated. Groundwater level and water temperature were hourly measured at the well developed for usage of open loop ground source heat pump system from 11 October 2013 to 8 January 2014. Groundwater was sampled in January and August 2013 and its chemical and isotopic compositions were analyzed. The bedrock of study area is the Jurassic granodiorite that mainly consists of quartz (27.9 to 46.8%), plagioclase (26.0 to 45.5%), and alkali feldspar (9.5 to 18.7%). The groundwater level ranged from 68.30 to 68.94 m (above mean sea level). Recharge rate was estimated using modified watertable fluctuation method and the recharge ratios was 9.1%. The water temperature ranged from 14.8 to 15.0oC. The vertical Increase rates of water temperature were 1.91 to 1.94/100 m. The water temperature showed the significant seasonal variation above 50 m depth, but had constant value below 50 m depth. Therefore, heat energy of the groundwater can be used securely in open loop ground source heat pump system. Electrical conductivity ranged from 120 to 320 µS/cm in dry season and from 133 to 310 µS/cm in wet season. The electrical conductivity gradually decreased with depth. In particular, electrical conductivity in approximately 30 m depth decreased dramatically (287 to 249 µS/cm) in wet season. The groundwater was Ca-HCO3 type. The concentrations of dissolved components did not show the vertically significant variations from 0 to 250 m depth. The δ18O and δD ranged from -9.5 to -9.4‰ and from -69 to -68‰. This work is supported by the New and Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No.20123040110010).
19. Understanding hydrogen sorption in a metal-organic framework with open-metal sites and amide functional groups
KAUST Repository
Pham, Tony T.
2013-05-09
/catalytic sites and characteristics through the active interplay of theory and experiment. The ability of accurate, carefully parametrized and transferable force fields to model and predict small molecule sorption in MOFs, even including open-metal sites, is demonstrated. © 2013 American Chemical Society.
20. [Post-appendectomy surgical site infection: overall rate and type according to open/laparoscopic approach].
Science.gov (United States)
Aranda-Narváez, José Manuel; Prieto-Puga Arjona, Tatiana; García-Albiach, Beatriz; Montiel-Casado, María Custodia; González-Sánchez, Antonio Jesús; Sánchez-Pérez, Belinda; Titos-García, Alberto; Santoyo-Santoyo, Julio
2014-02-01
To compare the incidence and profile of surgical site infection (SSI) after laparoscopic (LA) or open (OA) appendicectomy. Observational and analytical study was conducted on patients older than 14years-old with suspected acute appendicitis operated on within a 4-year period (2007-2010) at a third level hospital (n=868). They were divided in two groups according to the type of appendicectomy (LA, study group, 135; OA, control group, 733). The primary endpoint was a surgical site infection (SSI), and to determine the overall rate and types (incisional/organ-space). The risk of SSI was stratified by: i)National Nosocomial Infection Surveillance (NNIS) index (low risk: 0E, 0 and 1; high risk: 2 and 3); ii)status on presentation (low risk: normal or phlegmonous; high risk: gangrenous or perforated). The statistical analysis was performed using the software SPSS. The main result and stratified analysis was determined with χ(2), and the risk parameters using OR and Mantel-Haenszel OR with 95%CI, accepting statistical significance with P<.05. Age, gender, ASA index and incidence of advanced cases were similar in both groups. The overall SSI rate was 13.4% (more than a half of them detected during follow-up after discharge). Type of SSI: OA, 13% (superficial 9%, deep 2%, organ-space 2%); AL, 14% (superficial 5%, deep 1%, organ-space 8%) (overall: not significant; distribution: P<.000). Stratified analysis showed that there is an association between incisional SSI/OA and organ-space SSI/LA, and is particularly stronger in those patients with high risk of postoperative SSI (high risk NNIS or gangrenous-perforated presentation). OA and LA are associated with a higher rate of incisional and organ-space SSI respectively. This is particularly evident in patients with high risk of SSI. Copyright © 2012 Elsevier España, S.L. All rights reserved.
1. Carbon Flux to the Deep in three open sites of the Southern European Seas
Science.gov (United States)
Gogou*, A.; Sanchez-Vidal*, A.; Stavrakakis, S.; Durrieu de Madron, X.; Calafat, A. M.; Stabholz, M.; Psarra, S.; Canals, M.; Heussner, S.; Stavrakaki, I.; Papathanassiou, E.
2012-04-01
seasonality of the POC production and export to depth. The fraction of primary production that is exported out of the euphotic zone ranges from 7 to 15%, while the fraction of primary production exported below 2000 m depth was 0.61%, 0.34% and 0.97% in the WMED, EMED and BS, respectively. Export rates at the BS and WMED sites found to be slightly higher, while this at the EMED site to be comparable to the global ocean average of 0.31% at 2500 m depth (Lutz et al., 2007). POC export to depth are driven by meso-scale current activity, vertical mixing events, riverine discharges and atmospheric deposition. Understanding the processes driving carbon cycle in the SES is important for assessing the impacts of the predicted climate change in this region, with an ultimate goal to be included in the global ocean carbon models. *Authors AG and AS-V contributed equally to this work
2. The Surface Groups and Active Site of Fibrous Mineral Materials
Institute of Scientific and Technical Information of China (English)
DONG Fa-qin; WAN Pu; FENG Qi-ming; SONG Gong-bao; PENG Tong-jiang; LI Ping; LI Guo-wu
2004-01-01
The exposed and transformed groups of fibrous brucite,wollastonite,chrysotile asbestos,sepiolite,palygorskite,clinoptilolite,crocidolite and diatomaceous earth mineral materials are analyzed by IR spectra after acid and alikali etching,strong mechanical and polarity molecular interaction.The results show the active sites concentrate on the ends in stick mineral materials and on the defect or hole edge in pipe mineral materials.The inside active site of mineral materials plays a main role in small molecular substance.The shape of minerals influence their distribution and density of active site.The strong mechanical impulsion and weak chemical force change the active site feature of minerals,the powder process enables minerals exposed more surface group and more combined types.The surface processing with the small polarity molecular or the brand of middle molecular may produce ionation and new coordinate bond,and change the active properties and level of original mineral materials.
3. Incisional Surgical Site Infection after Elective Open Surgery for Colorectal Cancer
Directory of Open Access Journals (Sweden)
Kosuke Ishikawa
2014-01-01
Full Text Available Background. The purpose of this study was to clarify the incidence and risk factors for incisional surgical site infections (SSI in patients undergoing elective open surgery for colorectal cancer. Methods. We conducted prospective surveillance of incisional SSI after elective colorectal resections performed by a single surgeon for a 1-year period. Variables associated with infection, as identified in the literature, were collected and statistically analyzed for their association with incisional SSI development. Results. A total of 224 patients were identified for evaluation. The mean patient age was 67 years, and 120 (55% were male. Thirty-three (14.7% patients were diagnosed with incisional SSI. Multivariate analysis suggested that incisional SSI was independently associated with TNM stages III and IV (odds ratio [OR], 2.4 and intraoperative hypotension (OR, 3.4. Conclusions. The incidence of incisional SSI in our cohort was well within values generally reported in the literature. Our data suggest the importance of the maintenance of intraoperative normotension to reduce the development of incisional SSI.
4. Chemical or biological activity in open chaotic flows
Energy Technology Data Exchange (ETDEWEB)
Karolyi, G. [Department of Civil Engineering Mechanics, Technical University of Budapest, Muegyetem rkp. 3, H-1521 Budapest (Hungary); Pentek, A. [Marine Physical Laboratory, University of California at San Diego, La Jolla, California 92093-0238 (United States); Toroczkai, Z. [Center for Stochastic Processes in Science and Engineering and Department of Physics, Virginia Polytechnic Institute, Blacksburg, Virgina 24061-0435 (United States); Toroczkai, Z.; Tel, T. [Institute for Theoretical Physics, Eoetvoes University, P.O. Box 32, H-1518 Budapest (Hungary); Grebogi, C. [Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 (United States)
1999-05-01
We investigate the evolution of particle ensembles in open chaotic hydrodynamical flows. Active processes of the type A+B{r_arrow}2B and A+B{r_arrow}2C are considered in the limit of weak diffusion. As an illustrative advection dynamics we consider a model of the von K{acute a}rm{acute a}n vortex street, a time-periodic two-dimensional flow of a viscous fluid around a cylinder. We show that a fractal unstable manifold acts as a catalyst for the process, and the products cover fattened-up copies of this manifold. This may account for the observed filamental intensification of activity in environmental flows. The reaction equations valid in the wake are derived either in the form of dissipative maps or differential equations depending on the regime under consideration. They contain terms that are not present in the traditional reaction equations of the same active process: the decay of the products is slower while the productivity is much faster than in homogeneous flows. Both effects appear as a consequence of underlying fractal structures. In the long time limit, the system locks itself in a dynamic equilibrium state synchronized to the flow for both types of reactions. For particles of finite size an emptying transition might also occur leading to no products left in the wake. {copyright} {ital 1999} {ital The American Physical Society}
5. Chemical or Biological Activity in Open Chaotic Flows
CERN Document Server
Karolyi, G; Toroczkai, Z; Tél, T; Grebogi, C; Karolyi, Gy.
1999-01-01
We investigate the evolution of particle ensembles in open chaotic hydrodynamical flows. Active processes of the type A+B --> 2B and A+B --> 2C are considered in the limit of weak diffusion. As an illustrative advection dynamics we consider a model of the von Kármán vortex street, a time periodic two-dimensional flow of a viscous fluid around a cylinder. We show that a fractal unstable manifold acts as a catalyst for the process, and the products cover fattened-up copies of this manifold. This may account for the observed filamental intensification of activity in environmental flows. The reaction equations valid in the wake are derived either in the form of dissipative maps or differential equations depending on the regime under consideration. They contain terms that are not present in the traditional reaction equations of the same active process: the decay of the products is slower while the productivity is much faster than in homogeneous flows. Both effects appear as a consequence of underlying fractal st...
6. Resolving the Structure of Active Sites on Platinum Catalytic Nanoparticles
DEFF Research Database (Denmark)
Chang, Lan Yun; Barnard, Amanda S.; Gontard, Lionel Cervera
2010-01-01
Accurate understanding of the structure of active sites is fundamentally important in predicting catalytic properties of heterogeneous nanocatalysts. We present an accurate determination of both experimental and theoretical atomic structures of surface monatomic steps on industrial platinum nanop...
7. Physical activity and cancer risk: dose-response and cancer, all sites and site-specific.
Science.gov (United States)
Thune, I; Furberg, A S
2001-06-01
The association between physical activity and overall and site-specific cancer risk is elaborated in relation to whether any observed dose-response association between physical activity and cancer can be interpreted in terms of how much physical activity (type, intensity, duration, frequency) is needed to influence site- and gender-specific cancer risk. Observational studies were reviewed that have examined the independent effect of the volume of occupational physical activity (OPA) and/or leisure time physical activity (LPA) on overall and site-specific cancer risk. The evidence of cohort and case-control studies suggests that both leisure time and occupational physical activity protect against overall cancer risk, with a graded dose-response association suggested in both sexes. Confounding effects such as diet, body weight, and parity are often included as a covariate in the analyses, with little influence on the observed associations. A crude graded inverse dose-response association was observed between physical activity and colon cancer in 48 studies including 40,674 colon/colorectal cancer cases for both sexes. A dose-response effect of physical activity on colon cancer risk was especially observed, when participation in activities of at least moderate activity (>4.5 MET) and demonstrated by activities expressed as MET-hours per week. An observed inverse association with a dose-response relationship between physical activity and breast cancer was also identified in the majority of the 41 studies including 108,031 breast cancer cases. The dose-response relationship was in particular observed in case-control studies and supported by observations in cohort studies when participation in activities of at least moderate activity (>4.5 MET) and demonstrated by activities expressed by MET-hours per week. This association between physical activity and breast cancer risk is possibly dependent on age at exposure, age at diagnosis, menopausal status and other effect
8. Synthesis and Biological Evaluation of 2-Aminobenzamide Derivatives as Antimicrobial Agents: Opening/Closing Pharmacophore Site
Directory of Open Access Journals (Sweden)
Yahia N. Mabkhot
2014-03-01
Full Text Available A series of new 2-aminobenzamide derivatives (1–10 has been synthesized in good to excellent yields by adopting both conventional and/or a time-efficient microwave assisted methodologies starting from isatoic anhydride (ISA and characterized on the basis of their physical, spectral and microanalytical data. Selected compounds of this series were then tested against various bacterial (Bacillus subtilis (RCMB 000107 and Staphylococcus aureus (RCMB 000106. Pseudomonas aeruginosa (RCMB 000102 and Escherichia coli (RCMB 000103 and fungal strains (Saccharomyces cerevisiae (RCMB 006002, Aspergillus fumigatus (RCMB 002003 and Candida albicans (RCMB 005002 to explore their potential as antimicrobial agents. Compound 5 was found to be the most active compound among those tested, which showed excellent antifungal activity against Aspergillus fumigatus (RCMB 002003 more potent than standard Clotrimazole, and moderate to good antibacterial and antifungal activity against most of the other strains of bacteria and fungi. Furthermore, potential pharmacophore sites were identified and their activity was related with the structures in the solution.
9. 2008 LHC Open Days: Super(-conducting) events and activities
CERN Multimedia
2008-01-01
Superconductivity will be one of the central themes of the programme of events and discovery activities of the forthcoming LHC Open Days on 5 and 6 April. Visitors will be invited to take part in a range of activities, experiments and exchanges all about this amazing aspect of the LHC project. Why superconductivity? Simply because it’s the principle on which the very operation of the LHC is based. At the heart of the LHC magnets lie 7000 kilometres of superconducting cables, each strand containing between 6000 and 9000 filaments of the superconducting alloy niobium-titanium in a copper coating. These cables, cooled to a temperature close to absolute zero, are able to conduct electricity without resistance. 12000 amp currents - an intensity some 30000 times greater than that of a 100 watt light bulb - pass through the cables of the LHC magnets. Programme: BLDG 163 (Saturday 5 and Sunday 6 April): See weird and wonderful experiments with your own eyes In the workshop where the 2...
10. The effect of the site of laser zona opening on the complete hatching of mouse blastocysts and their cell numbers.
Science.gov (United States)
Sanmee, Usanee; Piromlertamorn, Waraporn; Vutyavanich, Teraporn
2016-09-01
We studied the effect of the site of laser zona opening on the complete hatching of mouse blastocysts and the cell numbers of the completely hatched blastocysts. Mouse blastocysts were randomly allocated to the inner cell mass (ICM) group (zona opening performed at the site of the ICM, n=125), the trophectoderm (TE) group (zona opening performed opposite to the ICM, n=125) and the control group (no zona opening, n=125). The rate of complete hatching of the blastocysts was not significantly different in the ICM and the TE group (84.8% vs 80.8%, respectively; p=0.402), but was significantly lower in the control group (51.2%, p<0.001). The cell numbers in the completely hatched blastocysts were comparable in the control group, the ICM group, and the TE group (69±19.3, 74±15.7, and 71±16.8, respectively; p=0.680). These findings indicate that the site of laser zona opening did not influence the rate of complete hatching of mouse blastocysts or their cell numbers.
11. Time and space in the middle paleolithic: Spatial structure and occupation dynamics of seven open-air sites.
Science.gov (United States)
Clark, Amy E
2016-05-06
The spatial structure of archeological sites can help reconstruct the settlement dynamics of hunter-gatherers by providing information on the number and length of occupations. This study seeks to access this information through a comparison of seven sites. These sites are open-air and were all excavated over large spatial areas, up to 2,000 m(2) , and are therefore ideal for spatial analysis, which was done using two complementary methods, lithic refitting and density zones. Both methods were assessed statistically using confidence intervals. The statistically significant results from each site were then compiled to evaluate trends that occur across the seven sites. These results were used to assess the "spatial consistency" of each assemblage and, through that, the number and duration of occupations. This study demonstrates that spatial analysis can be a powerful tool in research on occupation dynamics and can help disentangle the many occupations that often make up an archeological assemblage.
12. Sparsification of Neuronal Activity in the Visual Cortex at Eye-Opening
National Research Council Canada - National Science Library
Nathalie L. Rochefort; Olga Garaschuk; Ruxandra-Lulia Milos; Madoka Narushima; Nima Marandi; Bruno Pichler; Yury Kovalchuk; Arthur Konnerth; Bert Sakmann
2009-01-01
Eye-opening represents a turning point in thè function of the visual cortex. Before eye-opening, the visual cortex is largely devoid of sensory inputs and neuronal activities are generated intrinsically...
13. Methanopyrus kandleri topoisomerase V contains three distinct AP lyase active sites in addition to the topoisomerase active site.
Science.gov (United States)
Rajan, Rakhi; Osterman, Amy; Mondragón, Alfonso
2016-04-20
Topoisomerase V (Topo-V) is the only topoisomerase with both topoisomerase and DNA repair activities. The topoisomerase activity is conferred by a small alpha-helical domain, whereas the AP lyase activity is found in a region formed by 12 tandem helix-hairpin-helix ((HhH)2) domains. Although it was known that Topo-V has multiple repair sites, only one had been mapped. Here, we show that Topo-V has three AP lyase sites. The atomic structure and Small Angle X-ray Scattering studies of a 97 kDa fragment spanning the topoisomerase and 10 (HhH)2 domains reveal that the (HhH)2 domains extend away from the topoisomerase domain. A combination of biochemical and structural observations allow the mapping of the second repair site to the junction of the 9th and 10th (HhH)2 domains. The second site is structurally similar to the first one and to the sites found in other AP lyases. The 3rd AP lyase site is located in the 12th (HhH)2 domain. The results show that Topo-V is an unusual protein: it is the only known protein with more than one (HhH)2 domain, the only known topoisomerase with dual activities and is also unique by having three AP lyase repair sites in the same polypeptide.
14. CAN OPEN MEAN TERBUKA? NEGOTIATING LICENSES FOR INDONESIAN VIDEO ACTIVISM
Directory of Open Access Journals (Sweden)
Alexandra Crosby
2010-01-01
Full Text Available Abstract: Since the fall of Suharto’s New Order regime in Indonesia, space has been opened up for the emergence and development of new practices of media production and distribution, such as the use of video for social change. As access to the technology for producing, distributing and watching video becomes increasingly democratised in Indonesia over this period, a spectrum of approaches to licensing are developing in response to ideology as well as economic impetus. These include the full adherence to the global norms of intellectual property rights, market-driven piracy, politically based rejection of any restrictions, and a burgeoning interest in Creative Commons.While Indonesia hosts one of the most enthusiastic cultures of digital sharing, this article argues that there is not yet a solution for the issues of copyright management that fits the Indonesian context. We examine the work of several groups who are currently active in producing social and environmental video in the archipelago. These include VideoBattle, Forum Lenteng, and the EngageMedia network.
15. Laparoendoscopic single-site retroperitoneoscopic adrenalectomy compared with conventional laparoscopy and open surgery
Directory of Open Access Journals (Sweden)
Szu-Han Chen
2017-03-01
Conclusion: The standard approach to adrenalectomy recently improved from open to laparoscopic surgery, transperitoneal to retroperitoneal access, and multiple ports to a single port. Here we found that laparoscopic surgery had better intra- and postoperative outcomes than open surgery. Furthermore, patients treated with LESS-RA required less postoperative recovery time and less analgesic use than those treated with CRA.
16. Magnesium-Dependent Active-Site Conformational Selection in the Diels-Alderase Ribozyme
Energy Technology Data Exchange (ETDEWEB)
Berezniak, Tomasz [University of Heidelberg; Zahran, Mai [ORNL; Imhof, Petra [University of Heidelberg; Jaeschke, Andres [Free University of Berlin; Smith, Jeremy C [ORNL
2010-10-01
The Diels-Alderase ribozyme, an in vitro-evolved ribonucleic acid enzyme, accelerates the formation of carbon-carbon bonds between an anthracene diene and a maleimide dienophile in a [4 + 2] cycloaddition, a reaction with broad application in organic chemistry. Here, the Diels-Alderase ribozyme is examined via molecular dynamics (MD) simulations in both crystalline and aqueous solution environments. The simulations indicate that the catalytic pocket is highly dynamic. At low Mg(2+) ion concentrations, inactive states with the catalytic pocket closed dominate. Stabilization of the enzymatically active, open state of the catalytic pocket requires a high concentration of Mg(2+) ions (e.g., 54 mM), with cations binding to specific phosphate sites on the backbone of the residues bridging the opposite strands of the pocket. The free energy profile for pocket opening at high Mg(2+) cation concentration exhibits a double minimum, with a barrier to opening of approximately 5.5 kJ/mol and the closed state approximately 3 kJ/mol lower than the open state. Selection of the open state on substrate binding leads to the catalytic activity of the ribozyme. The simulation results explain structurally the experimental observation that full catalytic activity depends on the Mg(2+) ion concentration
17. Experimental and numerical study of open-air active cooling
Science.gov (United States)
Al-Fifi, Salman Amsari
The topic of my thesis is Experimental and Numerical Study of Open Air Active Cooling. The present research is intended to investigate experimentally and Numerically the effectiveness of cooling large open areas like stadiums, shopping malls, national gardens, amusement parks, zoos, transportation facilities and government facilities or even in buildings outdoor gardens and patios. Our cooling systems are simple cooling fans with different diameters and a mist system. This type of cooling systems has been chosen among the others to guarantee less energy consumption, which will make it the most favorable and applicable for cooling such places mentioned above. In the experiments, the main focus is to study the temperature domain as a function of different fan diameters aerodynamically similar in different heights till we come up with an empirical relationship that can determine the temperature domain for different fan diameters and for different heights of these fans. The experimental part has two stages. The first stage is devoted to investigate the maximum range of airspeed and profile for three different fan diameters and for different heights without mist, while the second stage is devoted to investigate the maximum range of temperature and profile for the three different diameter fans and for different heights with mist. The computational study is devoted to built an experimentally verified mathematical model to be used in the design and optimization of water mist cooling systems, and to compare the mathematical results to the experimental results and to get an insight of how to apply such evaporative mist cooling for different places for different conditions. In this study, numerical solution is presented based on experimental conditions, such dry bulb temperature, wet bulb temperature, relative humidity, operating pressure and fan airspeed. In the computational study, all experimental conditions are kept the same for the three fans except the fan airspeed
18. Human Glycinamide Ribonucleotide Transformylase: Active Site Mutants as Mechanistic Probes†
OpenAIRE
Manieri, Wanda; Moore, Molly E.; Soellner, Matthew B.; Tsang, Pearl; Caperelli, Carol A.
2007-01-01
Human glycinamide ribonucleotide transformylase (GART) (EC2.1.2.2) is a validated target for cancer chemotherapy, but mechanistic studies of this therapeutically important enzyme are limited. Site-directed mutagenesis, initial velocity studies, pH-rate studies, and substrate binding studies have been employed to probe the role of the strictly conserved active site residues, N106, H108, D144, and the semi-conserved K170 in substrate binding and catalysis. Only two conservative substitutions, N...
19. Active chemisorption sites in functionalized ionic liquids for carbon capture.
Science.gov (United States)
Cui, Guokai; Wang, Jianji; Zhang, Suojiang
2016-07-25
Development of novel technologies for the efficient and reversible capture of CO2 is highly desired. In the last decade, CO2 capture using ionic liquids has attracted intensive attention from both academia and industry, and has been recognized as a very promising technology. Recently, a new approach has been developed for highly efficient capture of CO2 by site-containing ionic liquids through chemical interaction. This perspective review focuses on the recent advances in the chemical absorption of CO2 using site-containing ionic liquids, such as amino-based ionic liquids, azolate ionic liquids, phenolate ionic liquids, dual-functionalized ionic liquids, pyridine-containing ionic liquids and so on. Other site-containing liquid absorbents such as amine-based solutions, switchable solvents, and functionalized ionic liquid-amine blends are also investigated. Strategies have been discussed for how to activate the existent reactive sites and develop novel reactive sites by physical and chemical methods to enhance CO2 absorption capacity and reduce absorption enthalpy. The carbon capture mechanisms of these site-containing liquid absorbents are also presented. Particular attention has been paid to the latest progress in CO2 capture in multiple-site interactions by amino-free anion-functionalized ionic liquids. In the last section, future directions and prospects for carbon capture by site-containing ionic liquids are outlined.
20. Active Sites Environmental Monitoring Program: Mid-FY 1991 report
Energy Technology Data Exchange (ETDEWEB)
Ashwood, T.L.; Wickliff, D.S.; Morrissey, C.M.
1991-10-01
This report summarizes the activities of the Active Sites Environmental Monitoring Program (ASEMP) from October 1990 through March 1991. The ASEMP was established in 1989 by Solid Waste Operations and the Environmental Sciences Division to provide early detection and performance monitoring at active low-level radioactive waste (LLW) disposal sites in Solid Waste Storage Area (SWSA) 6 and transuranic (TRU) waste storage sites in SWSA 5 as required by chapters II and III of US Department of Energy Order 5820.2A. Monitoring results continue to demonstrate the no LLW is being leached from the storage vaults on the tumulus pads. Loading of vaults on Tumulus II began during this reporting period and 115 vaults had been loaded by the end of March 1991.
1. De novo active sites for resurrected Precambrian enzymes
Science.gov (United States)
Risso, Valeria A.; Martinez-Rodriguez, Sergio; Candel, Adela M.; Krüger, Dennis M.; Pantoja-Uceda, David; Ortega-Muñoz, Mariano; Santoyo-Gonzalez, Francisco; Gaucher, Eric A.; Kamerlin, Shina C. L.; Bruix, Marta; Gavira, Jose A.; Sanchez-Ruiz, Jose M.
2017-07-01
Protein engineering studies often suggest the emergence of completely new enzyme functionalities to be highly improbable. However, enzymes likely catalysed many different reactions already in the last universal common ancestor. Mechanisms for the emergence of completely new active sites must therefore either plausibly exist or at least have existed at the primordial protein stage. Here, we use resurrected Precambrian proteins as scaffolds for protein engineering and demonstrate that a new active site can be generated through a single hydrophobic-to-ionizable amino acid replacement that generates a partially buried group with perturbed physico-chemical properties. We provide experimental and computational evidence that conformational flexibility can assist the emergence and subsequent evolution of new active sites by improving substrate and transition-state binding, through the sampling of many potentially productive conformations. Our results suggest a mechanism for the emergence of primordial enzymes and highlight the potential of ancestral reconstruction as a tool for protein engineering.
2. Oxygen reduction and evolution at single-metal active sites
DEFF Research Database (Denmark)
Calle-Vallejo, F.; Martínez, J.I.; García Lastra, Juan Maria
2013-01-01
of functionalized graphitic materials and gas-phase porphyrins with late transition metals. We find that both kinds of materials follow approximately the same activity trends, and active sites with transition metals from groups 7 to 9 may be good ORR and OER electrocatalysts. However, spin analyses show more...... overpotentials and is made of precious materials. A possible solution is the use of non-noble electrocatalysts with single-metal active sites. Here, on the basis of DFT calculations of adsorbed intermediates and a thermodynamic analysis, we compare the oxygen reduction (ORR) and evolution (OER) activities...... flexibility in the possible oxidation states of the metal atoms in solid electrocatalysts, while in porphyrins they must be +2. These observations reveal that the catalytic activity of these materials is mainly due to nearest-neighbor interactions. Based on this, we propose that this class of electrocatalysts...
3. Cellular automaton rules conserving the number of active sites
CERN Document Server
Boccara, N; Boccara, Nino; Fuks, Henryk
1997-01-01
This paper shows how to determine all the unidimensional two-state cellular automaton rules of a given number of inputs which conserve the number of active sites. These rules have to satisfy a necessary and sufficient condition. If the active sites are viewed as cells occupied by identical particles, these cellular automaton rules represent evolution operators of systems of identical interacting particles whose total number is conserved. Some of these rules, which allow motion in both directions, mimic ensembles of one-dimensional pseudo-random walkers. The corresponding stochastic processes are, however, not Gaussian.
4. Targeting Bax interaction sites reveals that only homo-oligomerization sites are essential for its activation
Science.gov (United States)
Peng, R; Tong, J-S; Li, H; Yue, B; Zou, F; Yu, J; Zhang, L
2013-01-01
Bax is a proapoptotic Bcl-2 family member that has a central role in the initiation of mitochondria-dependent apoptosis. However, the mechanism of Bax activation during apoptosis remains unsettled. It is believed that the activation of Bax is mediated by either dissociation from prosurvival Bcl-2 family members, or direct association with BH3-only members. Several interaction sites on Bax that mediate its interactions with other Bcl-2 family members, as well as its proapoptotic activity, have been identified in previous studies by other groups. To rigorously investigate the functional role of these interaction sites, we knocked in their respective mutants using HCT116 colon cancer cells, in which apoptosis induced by several stimuli is strictly Bax-dependent. Bax-mediated apoptosis was intact upon knock-in (KI) of K21E and D33A, which were shown to block the interaction of Bax with BH3-only activators. Apoptosis was partially reduced by KI of D68R, which impairs the interaction of Bax with prosurvival members, and S184V, a constitutively mitochondria-targeting mutant. In contrast, apoptosis was largely suppressed by KI of L70A/D71A, which blocks homo-oligomerization of Bax and its binding to prosurvival Bcl-2 family proteins. Collectively, our results suggest that the activation of endogenous Bax in HCT116 cells is dependent on its homo-oligomerization sites, but not those previously shown to interact with BH3-only activators or prosurvival proteins only. We therefore postulate that critical interaction sites yet to be identified, or mechanisms other than protein-protein interactions, need to be pursued to delineate the mechanism of Bax activation during apoptosis. PMID:23392123
5. Donor site morbidity following iliac crest bone harvesting for cervical fusion: a comparison between minimally invasive and open techniques
Science.gov (United States)
Pollock, Raymond; Bhatia, Chandra; Chuter, Graham; Lingutla, Kiran; Budithi, Chakravarty; Krishna, Manoj
2008-01-01
We have studied the occurrence of donor site morbidity, cosmesis and overall satisfaction with graft procedure in 76 patients who had undergone iliac crest bone harvesting for anterior cervical discectomy and fusion (ACDF). Totally 24 patients underwent an open procedure and 52 a minimally invasive trephine harvesting method. Although our study demonstrated substantial donor site pain and its effect on ambulation in both groups, this was of limited duration. Two patients, one in each group, suffered long-term pain that was eventually resolved. Totally 8.3% of patients in the open group suffered minor complications and 11.5% in the trephine group. There were two cases of meralgia parasthetica. There were no major complications in either group. There was no statistically significant difference in morbidity between the open and trephine groups. There was a trend towards significance (P = 0.076) for pain at the donor site, with less pain reported by patients who underwent the trephine procedure for harvesting. PMID:18389294
6. Openness to experience and activity engagement facilitate the maintenance of verbal ability in older adults.
Science.gov (United States)
Hogan, Michael J; Staff, Roger T; Bunting, Brendan P; Deary, Ian J; Whalley, Lawrence J
2012-12-01
The current study used data from the Aberdeen Birth Cohort, 1936, to investigate the hypothesis that the positive effects of the personality trait Openness on cognitive ability are mediated by activity levels. Results of latent growth modeling analysis revealed that higher Openness predicted better reading ability, inductive reasoning, and memory performance across three testing occasions when participants were aged 64-68 years. Higher Openness predicted higher activity levels, and higher activity levels in turn predicted higher reading ability, but not higher performance on measures of inductive reasoning, memory, and speed of processing. Overall, Openness and activity engagement appear related to preserved higher cognitive ability in older adults, with Openness having a direct effect on marker tests of fluid ability and with the combined influence of Openness and activity being particularly important for marker tests of crystallized intelligence.
7. Open innovation: the activities and views of companies in Wales
DEFF Research Database (Denmark)
Rhisiart, Martin; Djebarni, Rami; Thomas, Andrew
favoured by companies are: 1) Financial support for collaboration, 2) Increase co-funding schemes for SMEs’ R&D, 3) Improve the institutional framework for collaboration, 4) Improve access to governmental support, 5) Foster networks and clusters The report sets out seven key recommendations for promoting......This is the Final Report of a study conducted on open innovation in companies in Wales. The programme of research included a review of global literature, interviews with 15 companies, a survey and a focus group.The study discusses Government support measures for open innovation. Those most...... open innovation and the economic benefits that it can deliver in Wales. These depend on collaboration between business, government and academia. We indicate the organisations that should take these actions forward (business/government/academia/combination). This study was funded by the Welsh Government...
8. Active site modeling in copper azurin molecular dynamics simulations
NARCIS (Netherlands)
Rizzuti, B; Swart, M; Sportelli, L; Guzzi, R
2004-01-01
Active site modeling in molecular dynamics simulations is investigated for the reduced state of copper azurin. Five simulation runs (5 ns each) were performed at room temperature to study the consequences of a mixed electrostatic/constrained modeling for the coordination between the metal and the po
9. The nature of the active site in heterogeneous metal catalysis
DEFF Research Database (Denmark)
Nørskov, Jens Kehlet; Bligaard, Thomas; Larsen, Britt Hvolbæk
2008-01-01
This tutorial review, of relevance for the surface science and heterogeneous catalysis communities, provides a molecular-level discussion of the nature of the active sites in metal catalysis. Fundamental concepts such as "Bronsted-Evans-Polanyi relations'' and "volcano curves'' are introduced...
10. Chemical Modification of Papain and Subtilisin: An Active Site Comparison
Science.gov (United States)
St-Vincent, Mireille; Dickman, Michael
2004-01-01
An experiment using methyle methanethiosulfonate (MMTS) and phenylmethylsulfonyl flouride (PMSF) to specifically modify the cysteine and serine residues in the active sites of papain and subtilism respectively is demonstrated. The covalent modification of these enzymes and subsequent rescue of papain shows the beginning biochemist that proteins…
11. Functional and catalytic active sites prediction and docking analysis ...
African Journals Online (AJOL)
Bioinformatics
2015-07-01
Jul 1, 2015 ... industrially important azo dyes such as the molecular weight, molecular ... et al., 2010). The software possesses structure-based method to predict active sites in proteins based on a Difference of Gaussian (DoG) approach ...
12. Direct instrumental identification of catalytically active surface sites
Science.gov (United States)
Pfisterer, Jonas H. K.; Liang, Yunchang; Schneider, Oliver; Bandarenka, Aliaksandr S.
2017-09-01
The activity of heterogeneous catalysts—which are involved in some 80 per cent of processes in the chemical and energy industries—is determined by the electronic structure of specific surface sites that offer optimal binding of reaction intermediates. Directly identifying and monitoring these sites during a reaction should therefore provide insight that might aid the targeted development of heterogeneous catalysts and electrocatalysts (those that participate in electrochemical reactions) for practical applications. The invention of the scanning tunnelling microscope (STM) and the electrochemical STM promised to deliver such imaging capabilities, and both have indeed contributed greatly to our atomistic understanding of heterogeneous catalysis. But although the STM has been used to probe and initiate surface reactions, and has even enabled local measurements of reactivity in some systems, it is not generally thought to be suited to the direct identification of catalytically active surface sites under reaction conditions. Here we demonstrate, however, that common STMs can readily map the catalytic activity of surfaces with high spatial resolution: we show that by monitoring relative changes in the tunnelling current noise, active sites can be distinguished in an almost quantitative fashion according to their ability to catalyse the hydrogen-evolution reaction or the oxygen-reduction reaction. These data allow us to evaluate directly the importance and relative contribution to overall catalyst activity of different defects and sites at the boundaries between two materials. With its ability to deliver such information and its ready applicability to different systems, we anticipate that our method will aid the rational design of heterogeneous catalysts.
13. Modulation of RNase E activity by alternative RNA binding sites.
Directory of Open Access Journals (Sweden)
Daeyoung Kim
Full Text Available Endoribonuclease E (RNase E affects the composition and balance of the RNA population in Escherichia coli via degradation and processing of RNAs. In this study, we investigated the regulatory effects of an RNA binding site between amino acid residues 25 and 36 (24LYDLDIESPGHEQK37 of RNase E. Tandem mass spectrometry analysis of the N-terminal catalytic domain of RNase E (N-Rne that was UV crosslinked with a 5'-32P-end-labeled, 13-nt oligoribonucleotide (p-BR13 containing the RNase E cleavage site of RNA I revealed that two amino acid residues, Y25 and Q36, were bound to the cytosine and adenine of BR13, respectively. Based on these results, the Y25A N-Rne mutant was constructed, and was found to be hypoactive in comparison to wild-type and hyperactive Q36R mutant proteins. Mass spectrometry analysis showed that Y25A and Q36R mutations abolished the RNA binding to the uncompetitive inhibition site of RNase E. The Y25A mutation increased the RNA binding to the multimer formation interface between amino acid residues 427 and 433 (427LIEEEALK433, whereas the Q36R mutation enhanced the RNA binding to the catalytic site of the enzyme (65HGFLPL*K71. Electrophoretic mobility shift assays showed that the stable RNA-protein complex formation was positively correlated with the extent of RNA binding to the catalytic site and ribonucleolytic activity of the N-Rne proteins. These mutations exerted similar effects on the ribonucleolytic activity of the full-length RNase E in vivo. Our findings indicate that RNase E has two alternative RNA binding sites for modulating RNA binding to the catalytic site and the formation of a functional catalytic unit.
14. Role of active site rigidity in activity: MD simulation and fluorescence study on a lipase mutant.
Directory of Open Access Journals (Sweden)
Md Zahid Kamal
Full Text Available Relationship between stability and activity of enzymes is maintained by underlying conformational flexibility. In thermophilic enzymes, a decrease in flexibility causes low enzyme activity while in less stable proteins such as mesophiles and psychrophiles, an increase in flexibility is associated with enhanced enzyme activity. Recently, we identified a mutant of a lipase whose stability and activity were enhanced simultaneously. In this work, we probed the conformational dynamics of the mutant and the wild type lipase, particularly flexibility of their active site using molecular dynamic simulations and time-resolved fluorescence techniques. In contrast to the earlier observations, our data show that active site of the mutant is more rigid than wild type enzyme. Further investigation suggests that this lipase needs minimal reorganization/flexibility of active site residues during its catalytic cycle. Molecular dynamic simulations suggest that catalytically competent active site geometry of the mutant is relatively more preserved than wild type lipase, which might have led to its higher enzyme activity. Our study implies that widely accepted positive correlation between conformation flexibility and enzyme activity need not be stringent and draws attention to the possibility that high enzyme activity can still be accomplished in a rigid active site and stable protein structures. This finding has a significant implication towards better understanding of involvement of dynamic motions in enzyme catalysis and enzyme engineering through mutations in active site.
15. Activation of phenylalanine hydroxylase by phenylalanine does not require binding in the active site.
Science.gov (United States)
Roberts, Kenneth M; Khan, Crystal A; Hinck, Cynthia S; Fitzpatrick, Paul F
2014-12-16
Phenylalanine hydroxylase (PheH), a liver enzyme that catalyzes the hydroxylation of excess phenylalanine in the diet to tyrosine, is activated by phenylalanine. The lack of activity at low levels of phenylalanine has been attributed to the N-terminus of the protein's regulatory domain acting as an inhibitory peptide by blocking substrate access to the active site. The location of the site at which phenylalanine binds to activate the enzyme is unknown, and both the active site in the catalytic domain and a separate site in the N-terminal regulatory domain have been proposed. Binding of catecholamines to the active-site iron was used to probe the accessibility of the active site. Removal of the regulatory domain increases the rate constants for association of several catecholamines with the wild-type enzyme by ∼2-fold. Binding of phenylalanine in the active site is effectively abolished by mutating the active-site residue Arg270 to lysine. The k(cat)/K(phe) value is down 10⁴ for the mutant enzyme, and the K(m) value for phenylalanine for the mutant enzyme is >0.5 M. Incubation of the R270K enzyme with phenylalanine also results in a 2-fold increase in the rate constants for catecholamine binding. The change in the tryptophan fluorescence emission spectrum seen in the wild-type enzyme upon activation by phenylalanine is also seen with the R270K mutant enzyme in the presence of phenylalanine. Both results establish that activation of PheH by phenylalanine does not require binding of the amino acid in the active site. This is consistent with a separate allosteric site, likely in the regulatory domain.
16. Changes in active site histidine hydrogen bonding trigger cryptochrome activation.
Science.gov (United States)
Ganguly, Abir; Manahan, Craig C; Top, Deniz; Yee, Estella F; Lin, Changfan; Young, Michael W; Thiel, Walter; Crane, Brian R
2016-09-06
Cryptochrome (CRY) is the principal light sensor of the insect circadian clock. Photoreduction of the Drosophila CRY (dCRY) flavin cofactor to the anionic semiquinone (ASQ) restructures a C-terminal tail helix (CTT) that otherwise inhibits interactions with targets that include the clock protein Timeless (TIM). All-atom molecular dynamics (MD) simulations indicate that flavin reduction destabilizes the CTT, which undergoes large-scale conformational changes (the CTT release) on short (25 ns) timescales. The CTT release correlates with the conformation and protonation state of conserved His378, which resides between the CTT and the flavin cofactor. Poisson-Boltzmann calculations indicate that flavin reduction substantially increases the His378 pKa Consistent with coupling between ASQ formation and His378 protonation, dCRY displays reduced photoreduction rates with increasing pH; however, His378Asn/Arg variants show no such pH dependence. Replica-exchange MD simulations also support CTT release mediated by changes in His378 hydrogen bonding and verify other responsive regions of the protein previously identified by proteolytic sensitivity assays. His378 dCRY variants show varying abilities to light-activate TIM and undergo self-degradation in cellular assays. Surprisingly, His378Arg/Lys variants do not degrade in light despite maintaining reactivity toward TIM, thereby implicating different conformational responses in these two functions. Thus, the dCRY photosensory mechanism involves flavin photoreduction coupled to protonation of His378, whose perturbed hydrogen-bonding pattern alters the CTT and surrounding regions.
17. The role of internal coupling activities in explaining the effectiveness of open innovation
DEFF Research Database (Denmark)
Burcharth, Ana Luiza de Araújo; Knudsen, Mette Præst; Søndergaard, Helle Alsted
2013-01-01
This paper investigates the role of internal contingencies in explaining performance implications of open innovation by addressing the questions: does openness drive innovation performance? And if so, what organizational activities impact the effectiveness of both the inbound and the outbound...... finds that the effect of openness is mediated by the use of internal coupling activities that give employees latitude, information and skills to work autonomously. A key result is that the benefits of open innovation are fully captured only when firms adopt a number of activities that provide employees...
18. Public open space, physical activity, urban design and public health: Concepts, methods and research agenda.
Science.gov (United States)
Koohsari, Mohammad Javad; Mavoa, Suzanne; Villanueva, Karen; Sugiyama, Takemi; Badland, Hannah; Kaczynski, Andrew T; Owen, Neville; Giles-Corti, Billie
2015-05-01
Public open spaces such as parks and green spaces are key built environment elements within neighbourhoods for encouraging a variety of physical activity behaviours. Over the past decade, there has been a burgeoning number of active living research studies examining the influence of public open space on physical activity. However, the evidence shows mixed associations between different aspects of public open space (e.g., proximity, size, quality) and physical activity. These inconsistencies hinder the development of specific evidence-based guidelines for urban designers and policy-makers for (re)designing public open space to encourage physical activity. This paper aims to move this research agenda forward, by identifying key conceptual and methodological issues that may contribute to inconsistencies in research examining relations between public open space and physical activity.
19. Open-loop GPS signal tracking at low elevation angles from a ground-based observation site
Science.gov (United States)
Beyerle, Georg; Zus, Florian
2017-01-01
A 1-year data set of ground-based GPS signal observations aiming at geometric elevation angles below +2° is analysed. Within the "GLESER" measurement campaign about 2600 validated setting events were recorded by the "OpenGPS" open-loop tracking receiver at an observation site located at 52.3808° N, 13.0642° E between January and December 2014. The measurements confirm the feasibility of open-loop signal tracking down to geometric elevation angles of -1 to -1.5° extending the corresponding closed-loop tracking range by up to 1°. The study is based on the premise that observations of low-elevation events by a ground-based receiver may serve as test cases for space-based radio occultation measurements, even if the latter proceed at a significantly faster temporal scale. The results support the conclusion that the open-loop Doppler model has negligible influence on the derived carrier frequency profile for strong signal-to-noise density ratios above about 30 dB Hz. At lower signal levels, however, the OpenGPS receiver's dual-channel design, which tracks the same signal using two Doppler models differing by 10 Hz, uncovers a notable bias. The repeat patterns of the GPS orbit traces in terms of azimuth angle reveal characteristic signatures in both signal amplitude and Doppler frequency with respect to the topography close to the observation site. Mean vertical refractivity gradients, extracted from ECMWF meteorological fields, correlate weakly to moderately with observed signal amplitude fluctuations at geometric elevation angles between +1 and +2°. Results from multiple phase screen simulations support the interpretation that these fluctuations are at least partly produced by atmospheric multipath; at negative elevation angles diffraction at the ground surface seems to contribute.
20. Studies on the biotin-binding site of avidin. Tryptophan residues involved in the active site.
Science.gov (United States)
Gitlin, G; Bayer, E A; Wilchek, M
1988-01-01
Egg-white avidin was modified with the tryptophan-specific reagent 2-hydroxy-5-nitrobenzyl bromide. The complete loss of biotin-binding activity was achieved upon modification of an average of one tryptophan residue per avidin subunit. The identity of the modified residues was determined by isolating the relevant tryptic and chymotryptic peptides from CNBr-cleaved avidin fragments. The results demonstrate that Trp-70 and Trp-110 are modified in approximately equivalent proportions. It is believed that these residues are located in the active site of avidin and take part in the binding of biotin. PMID:3355517
1. Studies on the biotin-binding site of avidin. Tryptophan residues involved in the active site.
Science.gov (United States)
Gitlin, G; Bayer, E A; Wilchek, M
1988-02-15
Egg-white avidin was modified with the tryptophan-specific reagent 2-hydroxy-5-nitrobenzyl bromide. The complete loss of biotin-binding activity was achieved upon modification of an average of one tryptophan residue per avidin subunit. The identity of the modified residues was determined by isolating the relevant tryptic and chymotryptic peptides from CNBr-cleaved avidin fragments. The results demonstrate that Trp-70 and Trp-110 are modified in approximately equivalent proportions. It is believed that these residues are located in the active site of avidin and take part in the binding of biotin.
2. Study of contaminant transport at an open-tipping waste disposal site.
Science.gov (United States)
2013-07-01
Field and laboratory studies were conducted to estimate concentration of potential contaminants from landfill in the underlying groundwater, leachate, and surface water. Samples collected in the vicinity of the landfill were analyzed for physiochemical parameters, organic contaminants, and toxic heavy metals. Water quality results obtained were compared from published data and reports. The results indicate serious groundwater and surface water contamination in and around the waste disposal site. Analysis of the organic samples revealed that the site contains polychlorinated biphenyls and other organo-chlorine chemicals, principally chloro-benzenes. Although the amount of PCB concentration discovered was not extreme, their presence indicates a potentially serious environmental threat. Elevated concentrations of lead, copper, nickel, manganese, cadmium, and cobalt at the downgradient indicate that the contamination plume migrated further from the site, and the distribution of metals and metals containing wastes in the site is nonhomogeneous. These results clearly indicate that materials are poorly contained and are at risk of entering the environment. Therefore, full characterization of the dump contents and the integrity of the site are necessary to evaluate the scope of the problem and to identify suitable remediation options.
3. Enabling socio-economic activities: Opening global markets for the marginalized through secure ICT use
CSIR Research Space (South Africa)
Phahlamohlaka, Jackie
2016-08-01
Full Text Available This paper identifies and describes five economic activities through which ICT could effectively be used to open global markets for rural and marginalized communities. The activities are identified in contexts where there are no industries...
4. MONITORING OF IN-FIELD VARIABILITY FOR SITE SPECIFIC CROP MANAGEMENT THROUGH OPEN GEOSPATIAL INFORMATION
Directory of Open Access Journals (Sweden)
T. Řezník
2016-06-01
Full Text Available The agricultural sector is in a unique position due to its strategic importance around the world. It is crucial for both citizens (consumers and the economy (both regional and global, which, ideally, should ensure that the whole sector is a network of interacting organisations. It is important to develop new tools, management methods, and applications to improve the management and logistic operations of agricultural producers (farms and agricultural service providers. From a geospatial perspective, this involves identifying cost optimization pathways, reducing transport, reducing environmental loads, and improving the energy balance, while maintaining production levels, etc. This paper describes the benefits of, and open issues arising from, the development of the Open Farm Management Information System. Emphasis is placed on descriptions of available remote sensing and other geospatial data, and their harmonization, processing, and presentation to users. At the same time, the FOODIE platform also offers a novel approach of yield potential estimations. Validation for one farm demonstrated 70% successful rate when comparing yield results at a farm counting 1’284 hectares on one hand and results of a theoretical model of yield potential on the other hand. The presented Open Farm Management Information System has already been successfully registered under Phase 8 of the Global Earth Observation System of Systems (GEOSS Architecture Implementation Pilot in order to support the wide variety of demands that are primarily aimed at agriculture and water pollution monitoring by means of remote sensing.
5. Monitoring of In-Field Variability for Site Specific Crop Management Through Open Geospatial Information
Science.gov (United States)
Řezník, T.; Lukas, V.; Charvát, K.; Charvát, K., Jr.; Horáková, Š.; Křivánek, Z.; Herman, L.
2016-06-01
The agricultural sector is in a unique position due to its strategic importance around the world. It is crucial for both citizens (consumers) and the economy (both regional and global), which, ideally, should ensure that the whole sector is a network of interacting organisations. It is important to develop new tools, management methods, and applications to improve the management and logistic operations of agricultural producers (farms) and agricultural service providers. From a geospatial perspective, this involves identifying cost optimization pathways, reducing transport, reducing environmental loads, and improving the energy balance, while maintaining production levels, etc. This paper describes the benefits of, and open issues arising from, the development of the Open Farm Management Information System. Emphasis is placed on descriptions of available remote sensing and other geospatial data, and their harmonization, processing, and presentation to users. At the same time, the FOODIE platform also offers a novel approach of yield potential estimations. Validation for one farm demonstrated 70% successful rate when comparing yield results at a farm counting 1'284 hectares on one hand and results of a theoretical model of yield potential on the other hand. The presented Open Farm Management Information System has already been successfully registered under Phase 8 of the Global Earth Observation System of Systems (GEOSS) Architecture Implementation Pilot in order to support the wide variety of demands that are primarily aimed at agriculture and water pollution monitoring by means of remote sensing.
6. How to open & operate a financially successful web site design business
CERN Document Server
Evans, Charlotte
2009-01-01
The Pricing & Ethical Guidelines Handbook published by the Graphic Arts Guild reports that the average cost of designing a Web site for a small corporation can range from 7,750 to 15,000. It is incredibly easy to see the enormous profit potential. Web design businesses can be run part- or full-time and can easily be started in your own home. As such, they are one of the fastest growing segments of the Internet economy. Here is the manual you need to cash in on this highly profitable segment of the industry. This book is a comprehensive and detailed study of the business side of Web site des
7. The role of internal coupling activities in explaining the effectiveness of open innovation
DEFF Research Database (Denmark)
Burcharth, Ana Luiza de Araújo; Knudsen, Mette Præst; Søndergaard, Helle Alsted
2013-01-01
approaches to openness? The empirical basis of the study is a survey carried out in 321 Danish SMEs in manufacturing industries. The paper finds limited evidence of the direct effects of inbound and outbound open innovation on performance, as measured in terms of innovative output and profitability. It also......This paper investigates the role of internal contingencies in explaining performance implications of open innovation by addressing the questions: does openness drive innovation performance? And if so, what organizational activities impact the effectiveness of both the inbound and the outbound...... finds that the effect of openness is mediated by the use of internal coupling activities that give employees latitude, information and skills to work autonomously. A key result is that the benefits of open innovation are fully captured only when firms adopt a number of activities that provide employees...
8. Fragment-based identification of determinants of conformational and spectroscopic change at the ricin active site
Directory of Open Access Journals (Sweden)
Soares Alexei S
2007-11-01
Full Text Available Abstract Background Ricin is a potent toxin and known bioterrorism threat with no available antidote. The ricin A-chain (RTA acts enzymatically to cleave a specific adenine base from ribosomal RNA, thereby blocking translation. To understand better the relationship between ligand binding and RTA active site conformational change, we used a fragment-based approach to find a minimal set of bonding interactions able to induce rearrangements in critical side-chain positions. Results We found that the smallest ligand stabilizing an open conformer of the RTA active site pocket was an amide group, bound weakly by only a few hydrogen bonds to the protein. Complexes with small amide-containing molecules also revealed a switch in geometry from a parallel towards a splayed arrangement of an arginine-tryptophan cation-pi interaction that was associated with an increase and red-shift in tryptophan fluorescence upon ligand binding. Using the observed fluorescence signal, we determined the thermodynamic changes of adenine binding to the RTA active site, as well as the site-specific binding of urea. Urea binding had a favorable enthalpy change and unfavorable entropy change, with a ΔH of -13 ± 2 kJ/mol and a ΔS of -0.04 ± 0.01 kJ/(K*mol. The side-chain position of residue Tyr80 in a complex with adenine was found not to involve as large an overlap of rings with the purine as previously considered, suggesting a smaller role for aromatic stacking at the RTA active site. Conclusion We found that amide ligands can bind weakly but specifically to the ricin active site, producing significant shifts in positions of the critical active site residues Arg180 and Tyr80. These results indicate that fragment-based drug discovery methods are capable of identifying minimal bonding determinants of active-site side-chain rearrangements and the mechanistic origins of spectroscopic shifts. Our results suggest that tryptophan fluorescence provides a sensitive probe for the
9. Asymmetry of the Active Site Loop Conformation between Subunits of Glutamate-1-semialdehyde Aminomutase in Solution
Directory of Open Access Journals (Sweden)
Barbara Campanini
2013-01-01
Full Text Available Glutamate-1-semialdehyde aminomutase (GSAM is a dimeric, pyridoxal 5′-phosphate (PLP- dependent enzyme catalysing in plants and some bacteria the isomerization of L-glutamate-1-semialdehyde to 5-aminolevulinate, a common precursor of chlorophyll, haem, coenzyme B12, and other tetrapyrrolic compounds. During the catalytic cycle, the coenzyme undergoes conversion from pyridoxamine 5′-phosphate (PMP to PLP. The entrance of the catalytic site is protected by a loop that is believed to switch from an open to a closed conformation during catalysis. Crystallographic studies indicated that the structure of the mobile loop is related to the form of the cofactor bound to the active site, allowing for asymmetry within the dimer. Since no information on structural and functional asymmetry of the enzyme in solution is available in the literature, we investigated the active site accessibility by determining the cofactor fluorescence quenching of PMP- and PLP-GSAM forms. PLP-GSAM is partially quenched by potassium iodide, suggesting that at least one catalytic site is accessible to the anionic quencher and therefore confirming the asymmetry observed in the crystal structure. Iodide induces release of the cofactor from PMP-GSAM, apparently from only one catalytic site, therefore suggesting an asymmetry also in this form of the enzyme in solution, in contrast with the crystallographic data.
10. Active sites in char gasification: Final technical report
Energy Technology Data Exchange (ETDEWEB)
Wojtowicz, M.; Lilly, W.D.; Perkins, M.T.; Hradil, G.; Calo, J.M.; Suuberg, E.M.
1987-09-01
Among the key variables in the design of gasifiers and combustors is the reactivity of the chars which must be gasified or combusted. Significant loss of unburned char is unacceptable in virtually any process; the provision of sufficient residence time for complete conversion is essential. A very wide range of reactivities are observed, depending upon the nature of the char in a process. The current work focuses on furthering the understanding of gasification reactivities of chars. It has been well established that the reactivity of char to gasification generally depends upon three principal factors: (1) the concentration of ''active sites'' in the char; (2) mass transfer within the char; and (3) the type and concentration of catalytic impurities in the char. The present study primarily addresses the first factor. The subject of this research is the origin, nature, and fate of active sites in chars derived from parent hydrocarbons with coal-like structure. The nature and number of the active sites and their reactivity towards oxygen are examined in ''model'' chars derived from phenol-formaldehyde type resins. How the active sites are lost by the process of thermal annealing during heat treatment of chars are studied, and actual rate for the annealing process is derived. Since intrinsic char reactivities are of primary interest in the present study, a fair amount of attention was given to the model char synthesis and handling so that the effect of catalytic impurities and oxygen-containing functional groups in the chemical structure of the material were minimized, if not completely eliminated. The project would not be considered complete without comparing characteristic features of synthetic chars with kinetic behavior exhibited by natural chars, including coal chars.
11. Mechanochemical coupling in the myosin motor domain. I. Insights from equilibrium active-site simulations.
Directory of Open Access Journals (Sweden)
Haibo Yu
2007-02-01
Full Text Available Although the major structural transitions in molecular motors are often argued to couple to the binding of Adenosine triphosphate (ATP, the recovery stroke in the conventional myosin has been shown to be dependent on the hydrolysis of ATP. To obtain a clearer mechanistic picture for such "mechanochemical coupling" in myosin, equilibrium active-site simulations with explicit solvent have been carried out to probe the behavior of the motor domain as functions of the nucleotide chemical state and conformation of the converter/relay helix. In conjunction with previous studies of ATP hydrolysis with different active-site conformations and normal mode analysis of structural flexibility, the results help establish an energetics-based framework for understanding the mechanochemical coupling. It is proposed that the activation of hydrolysis does not require the rotation of the lever arm per se, but the two processes are tightly coordinated because both strongly couple to the open/close transition of the active site. The underlying picture involves shifts in the dominant population of different structural motifs as a consequence of changes elsewhere in the motor domain. The contribution of this work and the accompanying paper [] is to propose the actual mechanism behind these "population shifts" and residues that play important roles in the process. It is suggested that structural flexibilities at both the small and large scales inherent to the motor domain make it possible to implement tight couplings between different structural motifs while maintaining small free-energy drops for processes that occur in the detached states, which is likely a feature shared among many molecular motors. The significantly different flexibility of the active site in different X-ray structures with variable level arm orientations supports the notation that external force sensed by the lever arm may transmit into the active site and influence the chemical steps (nucleotide
12. Emission, speciation, and evaluation of impacts of non-methane volatile organic compounds from open dump site.
Science.gov (United States)
Majumdar, Dipanjali; Ray, Sandipan; Chakraborty, Sucharita; Rao, Padma S; Akolkar, A B; Chowdhury, M; Srivastava, Anjali
2014-07-01
Surface emission from Dhapa, the only garbage disposal ground in Kolkata, is a matter of concern to the local environment and also fuels the issues of occupational and environmental health. Surface emission of the Dhapa landfill site was studied using a flux chamber measurement for nonmethane volatile organic compounds (NMVOCs). Eighteen noncarbonyl volatile organic compounds (VOCs) and 14 carbonyl VOCs, including suspected and known carcinogens, were found in appreciable concentrations. The concentrations of the target species in the flux chamber were found to be significantly higher for most of the species in summer than winter. Surface emission rate of landfill gas was estimated by using two different approaches to assess the applicability for an open landfill site. It was found that the emissions predicted using the model Land GEM version 3.02 is one to two orders less than the emission rate calculated from flux chamber measurement for the target species. Tropospheric ozone formation has a serious impact for NMVOC emission. The total ozone-forming potential (OFP) of the Dhapa dumping ground considering all target NMVOCs was estimated to be 4.9E+04 and 1.2E+05 g/day in winter and summer, respectively. Also, it was found that carbonyl VOCs play a more important role than noncarbonyl VOCs for tropospheric ozone formation. Cumulative cancer risk estimated for all the carcinogenic species was found to be 2792 for 1 million population, while the total noncancer hazard index (HI) was estimated to be 246 for the occupational exposure to different compounds from surface emission to the dump-site workers at Dhapa. Implications: This paper describes the real-time surface emission of NMVOCs from an open municipal solid waste (MSW) dump site studied using a flux chamber. Our study findings indicate that while planning for new landfill site in tropical meteorology, real-time emission data must be considered, rather than relying on modeled data. The formation of tropospheric
13. Brownian aggregation rate of colloid particles with several active sites
Energy Technology Data Exchange (ETDEWEB)
Nekrasov, Vyacheslav M.; Yurkin, Maxim A.; Chernyshev, Andrei V., E-mail: [email protected] [Institute of Chemical Kinetics and Combustion, Institutskaya 3, 630090 Novosibirsk (Russian Federation); Physics Department, Novosibirsk State University, Pirogova 2, 630090 Novosibirsk (Russian Federation); Polshchitsin, Alexey A. [Institute of Chemical Kinetics and Combustion, Institutskaya 3, 630090 Novosibirsk (Russian Federation); JSC “VECTOR-BEST”, PO BOX 492, Novosibirsk 630117 (Russian Federation); Yakovleva, Galina E. [JSC “VECTOR-BEST”, PO BOX 492, Novosibirsk 630117 (Russian Federation); Maltsev, Valeri P. [Institute of Chemical Kinetics and Combustion, Institutskaya 3, 630090 Novosibirsk (Russian Federation); Physics Department, Novosibirsk State University, Pirogova 2, 630090 Novosibirsk (Russian Federation); Department of Preventive Medicine, Novosibirsk State Medical University, Krasny Prospect 52, 630091 Novosibirsk (Russian Federation)
2014-08-14
We theoretically analyze the aggregation kinetics of colloid particles with several active sites. Such particles (so-called “patchy particles”) are well known as chemically anisotropic reactants, but the corresponding rate constant of their aggregation has not yet been established in a convenient analytical form. Using kinematic approximation for the diffusion problem, we derived an analytical formula for the diffusion-controlled reaction rate constant between two colloid particles (or clusters) with several small active sites under the following assumptions: the relative translational motion is Brownian diffusion, and the isotropic stochastic reorientation of each particle is Markovian and arbitrarily correlated. This formula was shown to produce accurate results in comparison with more sophisticated approaches. Also, to account for the case of a low number of active sites per particle we used Monte Carlo stochastic algorithm based on Gillespie method. Simulations showed that such discrete model is required when this number is less than 10. Finally, we applied the developed approach to the simulation of immunoagglutination, assuming that the formed clusters have fractal structure.
14. [Mechanism of arginine deiminase activity by site-directed mutagenesis].
Science.gov (United States)
Li, Lifeng; Ni, Ye; Sun, Zhihao
2012-04-01
Arginine deiminase (ADI) has been studied as a potential anti-cancer agent for inhibiting arginine-auxotrophic tumors (such as melanomas and hepatocellular carcinomas) in phase III clinical trials. In this work, we studied the molecular mechanism of arginine deiminase activity by site-directed mutagenesis. Three mutation sites, A128, H404 and 1410, were introduced into wild-type ADI gene by QuikChange site-directed mutagenesis method, and four ADI mutants M1 (A128T), M2 (H404R), M3 (I410L), and M4 (A128T, H404R) were obtained. The ADI mutants were individually expressed in Escherichia coli BL21 (DE3), and the enzymatic properties of the purified mutant proteins were determined. The results show that both A128T and H404R had enhanced optimum pH, higher activity and stability of ADI under physiological condition (pH 7.4), as well as reduced K(m) value. This study provides an insight into the molecular mechanism of the ADI activity, and also the experimental evidence for the rational protein evolution in the future.
15. HDAC Inhibitors without an Active Site Zn2+-Binding Group
DEFF Research Database (Denmark)
Vickers, Chris J.; Olsen, Christian Adam; Leman, Luke J.
2012-01-01
Natural and synthetic histone deacetylase (HDAC) inhibitors generally derive their strong binding affinity and high potency from a key functional group that binds to the Zn2+ ion within the enzyme active site. However, this feature is also thought to carry the potential liability of undesirable off......-target interactions with other metalloenzymes. As a step toward mitigating this issue, here, we describe the design, synthesis, and structure−activity characterizations of cyclic α3β-tetrapeptide HDAC inhibitors that lack the presumed indispensable Zn2+-binding group. The lead compounds (e.g., 15 and 26) display good...
16. Seismic activity parameters of the Finnish potential repository sites
Energy Technology Data Exchange (ETDEWEB)
Saari, J. [Fortum Engineering Oy, Vantaa (Finland)
2000-10-01
Posiva Oy has started a project for estimating the possible earthquake induced rock movements on the deposition holes containing canisters of spent nuclear fuel. These estimates will be made for the four investigation sites, Romuvaara, Kivetty, Olkiluoto and Haestholmen. This study deals with the current and future seismicity associated with the above mentioned sites. Seismic belts that participate the seismic behaviour of the studied sites have been identified and the magnitude-frequency distributions of these belts have been estimated. The seismic activity parameters of the sites have been deduced from the characteristics of the seismic belts in order to forecast the seismicity during the next 100,000 years. The report discusses the possible earthquakes induced by future glaciation. The seismic interpretation seems to indicate that the previous postglacial faults in Finnish Lapland have been generated in compressional environment. The orientation of the rather uniform compression has been NW-SE, which coincide with the current stress field. It seems that, although the impact of postglacial crustal rebound must have been significant, the impact of plate tectonics has been dominant. A major assumption of this study has been that future seismicity will generally resemble the current seismicity. However, when the postglacial seismicity is concerned, the magnitude-frequency distribution is likely different and the expected maximum magnitude will be higher. Maximum magnitudes of future postglacial earthquakes have been approximated by strain release examinations. Seismicity has been examined within the framework of the lineament maps, in order to associate the future significant earthquakes with active fault zones in the vicinity of the potential repository sites. (orig.)
17. Identification and characterization of Kaposi's sarcoma-associated herpesvirus open reading frame 11 promotor activation
Energy Technology Data Exchange (ETDEWEB)
Chen, Lei [Los Alamos National Laboratory
2008-01-01
Open reading frame 11 (ORF11) of Kaposi's sarcoma-associated herpesvirus belongs to a herpesviral homologous protein family shared by some members of the gamma- herpesvirus subfamily. Little is known about this ORF11 homologous protein family. We have characterized an unknown open reading frame, ORF11, located adjacent and in the opposite orientation to a well-characterized viral IL-6 gene. Northern blot analysis reveals that ORF11 is expressed during the KSHV lytic cycle with delayed-early transcription kinetics. We have determined the 5{prime} and 3{prime} untranslated region of the unspliced ORF11 transcript and identified both the transcription start site and the transcription termination site. Core promoter region, representing ORF11 promoter activity, was mapped to a 159nt fragment 5{prime} most proximal to the transcription start site. A functional TATA box was identified in the core promoter region. Interestingly, we found that ORF11 transcriptional activation is not responsive to Rta, the KSHV lytic switch protein. We also discovered that part of the ORF11 promoter region, the 209nt fragment upstream of the transcription start site, was repressed by phorbol esters. Our data help to understand transcription regulation of ORF11 and to elucidate roles of ORF11 in KSHV pathogenesis and life cycle.
18. Jack bean urease: the effect of active-site binding inhibitors on the reactivity of enzyme thiol groups.
Science.gov (United States)
Krajewska, Barbara; Zaborska, Wiesława
2007-10-01
In view of the complexity of the role of the active site flap cysteine in the urease catalysis, in this work we studied how the presence of typical active-site binding inhibitors of urease, phenylphosphorodiamidate (PPD), acetohydroxamic acid (AHA), boric acid and fluoride, affects the reactivity of enzyme thiol groups, the active site flap thiol in particular. For that the inhibitor-urease complexes were prepared with excess inhibitors and had their thiol groups titrated with DTNB. The effects observed were analyzed in terms of the structures of the inhibitor-urease complexes reported in the literature. We found that the effectiveness in preventing the active site cysteine from the modification by disulfides, varied among the inhibitors studied, even though they all bind to the active site. The variations were accounted for by different extents of geometrical distortion in the active site that the inhibitors introduced upon binding, leaving the flap either open in AHA-, boric acid- and fluoride-inhibited urease, like in the native enzyme or closed in PPD-inhibited urease. Among the inhibitors, only PPD was found to be able to thoroughly protect the flap cysteines from the further reaction with disulfides, this apparently resulting from the closed conformation of the flap. Accordingly, in practical terms PPD may be regarded as the most suitable inhibitor for active-site protection experiments in inhibition studies of urease.
19. Predictive models of gas sorption in a metal-organic framework with open-metal sites and small pore sizes.
Science.gov (United States)
Pham, Tony; Forrest, Katherine A; Franz, Douglas M; Guo, Zhiyong; Chen, Banglin; Space, Brian
2017-07-19
Simulations of CO2 and H2 sorption were performed in UTSA-20, a metal-organic framework (MOF) having zyg topology and composed of Cu(2+) ions coordinated to 3,3',3'',5,5',5''-benzene-1,3,5-triyl-hexabenzoate (BHB) linkers. Previous experimental studies have shown that this MOF displays remarkable CO2 sorption properties and exhibits one of the highest gravimetric H2 uptakes at 77 K/1.0 atm (2.9 wt%) [Z. Guo, et al. Angew. Chem., Int. Ed., 2011, 50, 3178-3181]. For both sorbates, the simulations were executed with the inclusion of explicit many-body polarization interactions, which was necessary to reproduce sorption onto the open-metal sites. Non-polarizable potentials were also utilized for simulations of CO2 sorption as a control. The simulated excess sorption isotherms for both CO2 and H2 are in very good agreement with the corresponding experimental data over a wide range of temperatures and pressures, thus demonstrating the accuracy and predictive power of the polarizable potentials used herein. The theoretical isosteric heat of adsorption (Qst) values are also in good agreement with the newly reported experimental Qst values for the respective sorbates in UTSA-20. Sorption onto the more positively charged Cu(2+) ion of the [Cu2(O2CR)4] cluster was observed for both CO2 and H2. However, a binding site with energetics comparable to that for an open-metal site was also discovered for both sorbates. A radial distribution function (g(r)) analysis about the preferential Cu(2+) ions for CO2 and H2 revealed that both sorbates display different trends for the relative occupancy about such sites upon increasing/decreasing the pressure in the MOF. Overall, this study provides insights into the CO2 and H2 sorption mechanisms in this MOF containing open-metal sites and small pore sizes for the first time through a classical polarizable force field.
20. Soil criteria to protect terrestrial wildlife and open-range livestock from metal toxicity at mining sites.
Science.gov (United States)
Ford, Karl L; Beyer, W Nelson
2014-03-01
Thousands of hard rock mines exist in the western USA and in other parts of the world as a result of historic and current gold, silver, lead, and mercury mining. Many of these sites in the USA are on public lands. Typical mine waste associated with these sites are tailings and waste rock dumps that may be used by wildlife and open-range livestock. This report provides wildlife screening criteria levels for metals in soil and mine waste to evaluate risk and to determine the need for site-specific risk assessment, remediation, or a change in management practices. The screening levels are calculated from toxicity reference values based on maximum tolerable levels of metals in feed, on soil and plant ingestion rates, and on soil to plant uptake factors for a variety of receptors. The metals chosen for this report are common toxic metals found at mining sites: arsenic, cadmium, copper, lead, mercury, and zinc. The resulting soil screening values are well above those developed by the US Environmental Protection Agency. The difference in values was mainly a result of using toxicity reference values that were more specific to the receptors addressed rather than the most sensitive receptor.
1. Soil criteria to protect terrestrial wildlife and open-range livestock from metal toxicity at mining sites
Science.gov (United States)
Ford, Karl L; Beyer, W. Nelson
2014-01-01
Thousands of hard rock mines exist in the western USA and in other parts of the world as a result of historic and current gold, silver, lead, and mercury mining. Many of these sites in the USA are on public lands. Typical mine waste associated with these sites are tailings and waste rock dumps that may be used by wildlife and open-range livestock. This report provides wildlife screening criteria levels for metals in soil and mine waste to evaluate risk and to determine the need for site-specific risk assessment, remediation, or a change in management practices. The screening levels are calculated from toxicity reference values based on maximum tolerable levels of metals in feed, on soil and plant ingestion rates, and on soil to plant uptake factors for a variety of receptors. The metals chosen for this report are common toxic metals found at mining sites: arsenic, cadmium, copper, lead, mercury, and zinc. The resulting soil screening values are well above those developed by the US Environmental Protection Agency. The difference in values was mainly a result of using toxicity reference values that were more specific to the receptors addressed rather than the most sensitive receptor.
2. Overview of the activities carried out at the FEBEX site
Energy Technology Data Exchange (ETDEWEB)
Missana, T.; Buil, B.; Garralon, A.; Gomez, P. [CIEMAT, Dept. de Medioambien te, 28040 Madrid (Spain); Perez-Estaun, A.; Carbonell, R. [Inst. Jaume Almera, CSIC (Spain); Suso, J.; Carretero, G.; Bueno, J.; Martinez, L. [AITEMIN (Spain) ; Hernan, P. [ENRESA (Spain)
2007-06-15
One of the main aim of WP 4.1 and 4.2 is to study solute migration mechanisms in crystalline host-rock in realistic conditions. Many organisations are participating in a joint study that is being performed in the FEBEX gallery (NAGRA's Grimsel Test Site, GTS, Switzerland). The FEBEX experiment reproduces at a real scale a high-level waste repository in granite and was installed more than 9 years ago. At moment, it represents the most realistic environment where the processes affecting radionuclide migration from the bentonite to granite can be studied. This paper summarises the main activities carried out at the FEBEX site during the second year of the project.
3. Current activities handbook: formerly utilized sites remedial action program
Energy Technology Data Exchange (ETDEWEB)
None
1981-02-27
This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the activities each of the thirteen state legislatures potentially affected by the Formerly Utilized Sites Remedial Action Program. It contains a description of the state legislative procedural rules and a schedule of each legislative session; a summary of pending relevant legislation; the name and telephone number of legislative and state agency contacts; and the full text of all bills identified.
4. Nest predation increases with parental activity: separating nest site and parental activity effects.
OpenAIRE
Martin, T E; Scott, J; Menge, C
2000-01-01
Alexander Skutch hypothesized that increased parental activity can increase the risk of nest predation. We tested this hypothesis using ten open-nesting bird species in Arizona, USA. Parental activity was greater during the nestling than incubation stage because parents visited the nest frequently to feed their young during the nestling stage. However, nest predation did not generally increase with parental activity between nesting stages across the ten study species. Previous investigators h...
5. An Investigation into Social Learning Activities by Practitioners in Open Educational Practices
Science.gov (United States)
Schreurs, Bieke; Van den Beemt, Antoine; Prinsen, Fleur; Witthaus, Gabi; Conole, Gráinne; De Laat, Maarten
2014-01-01
By investigating how educational practitioners participate in activities around open educational practices (OEP), this paper aims at contributing to an understanding of open practices and how these practitioners learn to use OEP. Our research is guided by the following hypothesis: Different social configurations support a variety of social…
6. Using internal coupling activities to enhance the effectiveness of open innovation
DEFF Research Database (Denmark)
Burcharth, Ana Luiza de Araújo; Knudsen, Mette Præst; Søndergaard, Helle Alsted
This paper investigates the role of specific intra-organizational mechanisms in analyzing performance implications of openness by addressing two questions: does openness to innovation influence innovation performance? And if so, what organizational activities facilitate increased effectiveness...... practices, while distinguishing between respectively the effects of inbound and outbound openness on innovation performance. The paper concludes with implications to theory and practice....... of both inbound and outbound open innovation practices? The paper identifies a set of internal management mechanisms that allows the firm to couple the outside-in and inside-out knowledge flows in support of integrating external knowledge and internal competencies. The empirical basis of the study...
7. European citizenship and active citizenship: an ever open debate
Directory of Open Access Journals (Sweden)
Lauretta D’Angelo
2007-09-01
Full Text Available In the course of the last decade the European debate on the concept of citizenship has shown that a definition of this concept in strictly legal and jurisprudence terms is reductive. Indeed a behavioral element is present, which goes beyond the defence and request for defence of rights and duties, but actually stresses the importance of acting within a community (or within several communities. A citizenship belonging to a given space/time context which, to be authentic, requires know-how and know-how-to-be that can be gained in different training opportunities (formal, informal etc. with various active learning methodologies and through experience. The SEDEC project aims to investigate which teaching methodologies and activities specifically developed for the teaching of sciences can be applied in other learning contexts, in order to sustain actions for developing an active citizenship.
8. Dioxin-like and perfluorinated compounds in pigs in an Indian open waste dumping site: toxicokinetics and effects on hepatic cytochrome P450 and blood plasma hormones.
Science.gov (United States)
Watanabe, Michio X; Kunisue, Tatsuya; Tao, Lin; Kannan, Kurunthachalam; Subramanian, Annamalai; Tanabe, Shinsuke; Iwata, Hisato
2010-07-01
Dioxins and related compounds (DRCs) and perfluorinated compounds were measured in the livers of pigs (Sus scrofa) collected from an open waste dumping site in South India. Hepatic concentrations of DRCs and perfluorooctanesulfonate (PFOS; up to 200 ng/g wet wt) were significantly higher in male and female pigs, respectively, collected from the dumping site than in those from a reference site. Results suggest that dumping sites are a source of DRCs and PFOS. Hepatic concentrations of DRCs in piglets were higher than in mothers, especially for the congeners with molecular weights in the range of 360 to 400, implying congener-specific maternal transfer of DRCs in swine. Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans and some non-ortho dioxin-like polychlorinated biphenyls (PCBs) in the liver of pigs were higher than those in the adipose fat and muscle of the same specimens. In addition, the liver-to-adipose concentration ratios for each congener had a significant positive correlation with the levels of hepatic cytochrome P450 (CYP)1A-like protein, suggesting congener-specific and CYP1A-dependent hepatic sequestration of DRCs in the swine. Total hepatic 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs; 8.9-350 pg/g fat wt) had a significant positive correlation with CYP1A-like protein expression (r=0.56, p=0.012), suggesting the induction of CYP1A by DRCs. However, the total TEQs had a significant negative correlation with CYP4A-like protein (r=-0.49, p=0.029), suggesting repression of peroxisome proliferator-activated receptor-alpha (PPARalpha)-mediated signaling pathway by DRCs. Decreases in plasma total thyroxine (T4), free T4, and immunoglobulin (Ig) G were also found in pigs from the dumping site compared with those from the reference site. This study provides insight into the toxicological impacts of DRCs and perfluorinated compounds in wild animals from open waste dumping sites.
9. SITE-DIRECTED MUTAGENESIS OF PROPOSED ACTIVE-SITE RESIDUES OF PENICILLIN-BINDING PROTEIN-5 FROM ESCHERICHIA-COLI
NARCIS (Netherlands)
VANDERLINDEN, MPG; DEHAAN, L; DIDEBERG, O; KECK, W
1994-01-01
Alignment of the amino acid sequence of penicillin-binding protein 5 (PBP5) with the sequences of other members of the family of active-site-serine penicillin-interacting enzymes predicted the residues playing a role in the catalytic mechanism of PBP5. Apart from the active-site (Ser(44)), Lys(47),
10. Number of active transcription factor binding sites is essential for the Hes7 oscillator
Directory of Open Access Journals (Sweden)
de Angelis Martin
2006-02-01
Full Text Available Abstract Background It is commonly accepted that embryonic segmentation of vertebrates is regulated by a segmentation clock, which is induced by the cycling genes Hes1 and Hes7. Their products form dimers that bind to the regulatory regions and thereby repress the transcription of their own encoding genes. An increase of the half-life of Hes7 protein causes irregular somite formation. This was shown in recent experiments by Hirata et al. In the same work, numerical simulations from a delay differential equations model, originally invented by Lewis, gave additional support. For a longer half-life of the Hes7 protein, these simulations exhibited strongly damped oscillations with, after few periods, severely attenuated the amplitudes. In these simulations, the Hill coefficient, a crucial model parameter, was set to 2 indicating that Hes7 has only one binding site in its promoter. On the other hand, Bessho et al. established three regulatory elements in the promoter region. Results We show that – with the same half life – the delay system is highly sensitive to changes in the Hill coefficient. A small increase changes the qualitative behaviour of the solutions drastically. There is sustained oscillation and hence the model can no longer explain the disruption of the segmentation clock. On the other hand, the Hill coefficient is correlated with the number of active binding sites, and with the way in which dimers bind to them. In this paper, we adopt response functions in order to estimate Hill coefficients for a variable number of active binding sites. It turns out that three active transcription factor binding sites increase the Hill coefficient by at least 20% as compared to one single active site. Conclusion Our findings lead to the following crucial dichotomy: either Hirata's model is correct for the Hes7 oscillator, in which case at most two binding sites are active in its promoter region; or at least three binding sites are active, in which
11. A Description and Characterization of Student Activity in an Open, Online, Mathematics Help Forum
Science.gov (United States)
van de Sande, Carla
2011-01-01
Free, open, online, calculus forums are websites where students from around the world can post course-related queries that may be viewed and responded to by anonymous others. These sites are an emergent resource for students seeking help and have become a part of many students' mathematical experience. The purpose of this paper is to introduce and…
12. 77 FR 39508 - Commercial Wind Lease Issuance and Site Assessment Activities on the Atlantic Outer Continental...
Science.gov (United States)
2012-07-03
... characterization activities (geophysical, geotechnical, archaeological, and biological surveys needed to develop..., site characterization, and site assessment in and around the Call Area (76 FR 51391). The Call Area...
13. Study the active site of flavonoid applying radiation chemistry
Energy Technology Data Exchange (ETDEWEB)
Wu Jilan; Sun Gang; Zhang Fugen; He Yongke; Li Jiuqiang [Department of Technical Physics, Peking Univ., Beijing (China)
2000-03-01
Flavonoid are a large and important class of naturally occurring, low molecular weight benzo-{gamma}-pyrone derivatives which are reported to have a myriad of biological activities, but the study on the active sites of flavonoids is still ambiguous. In this paper, rutin, quercetin and baicalin have been selected as model compounds. It is well known that rutin is used in inhibiting arteriosclerosis and baicalin is antibacterial and antiviral. They have similar basic structure, but their medicinal properties are so different, why? As most flavonoids contain carbonyl group, which can capture electron effectively, we predict that flavonoids can capture electron to form radical anion. The formation of anion radical may have influence on the mitochondrial electron transport chain. The difference in the ability of forming anion radical may cause the difference in their medicinal effects. (author)
14. Late Pleistocene steppe lion Panthera leo spelaea (Goldfuss, 1810) footprints and bone records from open air sites in northern Germany - Evidence of hyena-lion antagonism and scavenging in Europe
Science.gov (United States)
Diedrich, Cajus G.
2011-07-01
Bone remains and a trackway of Pantheraichnus bottropensis nov. ichg. ichnsp. of the Late Pleistocene lion Panthera leo spelaea ( Goldfuss, 1810) have been recovered from Bottrop and other open air sites in northern Germany. Some of these bones are from open air hyena den sites. A relative high proportion of lion bones (20%) exhibit bite, chew or nibble marks, or bone crushing and nibbling caused by a large carnivore. Repeated patterns of similar bone damage have been compared to bone remains found at hyena dens in gypsum karst areas and cave sites in northern Germany. Ice Age spotted hyenas have been the main antagonists and the main scavengers on lion carcasses. The remains appear to have been imported often by hyenas into their communal dens, supporting the theory of strong hyena-lion antagonism, similar to the well documented antagonism between modern African lions and spotted hyenas. Most of the lion bones from the open air hyena den at Bottrop are probably a result of such antagonism, as are the rare remains of these carnivores found within large hyena prey bone accumulations along the Pleistocene rivers. The Emscher River terrace also has the largest quantity of hyena remains from open air river terrace sites in northern Germany. Their cub remains, and incomplete chewed prey bones from mammoths and woolly rhinoceroses, typical of hyena activity, underline the character of these sites as cub-raising and communal dens, where their prey was accumulated along the riverbanks in a similar manner to modern African hyenas.
15. Eel calcitonin binding site distribution and antinociceptive activity in rats
Energy Technology Data Exchange (ETDEWEB)
Guidobono, F.; Netti, C.; Sibilia, V.; Villa, I.; Zamboni, A.; Pecile, A.
1986-03-01
The distribution of binding site for (/sup 125/I)-eel-calcitonin (ECT) to rat central nervous system, studied by an autoradiographic technique, showed concentrations of binding in the diencephalon, the brain stem and the spinal cord. Large accumulations of grains were seen in the hypothalamus, the amygdala, in the fasciculus medialis prosencephali, in the fasciculus longitudinalis medialis, in the ventrolateral part of the periventricular gray matter, in the lemniscus medialis and in the raphe nuclei. The density of grains in the reticular formation and in the nucleus tractus spinalis nervi trigemini was more moderate. In the spinal cord, grains were scattered throughout the dorsal horns. Binding of the ligand was displaced equally by cold ECT and by salmon CT(sCT), indicating that both peptides bind to the same receptors. Human CT was much weaker than sCT in displacing (/sup 125/I)-ECT binding. The administration of ECT into the brain ventricles of rats dose-dependently induced a significant and long-lasting enhancement of hot-plate latencies comparable with that obtained with sCT. The antinociceptive activity induced by ECT is compatible with the topographical distribution of binding sites for the peptide and is a further indication that fish CTs are active in the mammalian brain.
16. Highly active and stereoselective zirconium and hafnium alkoxide initiators for solvent-free ring-opening polymerization of rac-lactide.
Science.gov (United States)
Chmura, Amanda J; Davidson, Matthew G; Frankis, Catherine J; Jones, Matthew D; Lunn, Matthew D
2008-03-21
Under solvent-free conditions (at 130 degrees C), zirconium and hafnium amine tris(phenolate) alkoxides are extremely active, well-controlled, single-site initiators for the ring-opening polymerization of rac-lactide, yielding highly heterotactic polylactide.
17. Low Cost Open-Path Instrument for Monitoring Atmospheric Carbon Dioxide at Sequestration Sites
Energy Technology Data Exchange (ETDEWEB)
William Goddard
2008-09-30
In the past 48 months of the project, we have accomplished all objectives outlined in the proposal. In the first year, we demonstrated the technology for remote sensing on a bench top scale. The core electronics are designed and fabricated. We achieved results that will safely deliver the specifications outlined in the proposal. In the 2nd year, 2 major technical tasks outlined in the Statement of Objectives, i.e. Build a field test ready prototype of a long-range CO2 monitor, and characterize its performance in the short term and demonstrate that the monitor characteristics meet the goals set in the initial proposal, have been accomplished. We also conducted simulation work that defines the different deployment strategies for our sensors at sequestration sites. In the 3rd year, Specifications and Testing protocols have been developed for the CO2 monitor. 1% accuracy had been demonstrated in short period tests ({approx}1 hour). Unattended system operation and stability over a period of a week has been demonstrated with and without EDFA (laser power amplifier). The sensitivity of the instrument to CO2 leaks has been demonstrated. In the 4th no-cost extension year, we further field tested the system and the experience we accumulated give us a clear picture of what else are needed for final field deployment. These results have shown all the objectives of the project have been fulfilled. In July 2008, along with our commercial partner we won the DOE STTR phase I award to commercialize the instrument developed in this project - a testimony to the achievement of this research.
18. Site characterization and related activities at the potential high-level radioactive waste repository site at Yucca Mountain, Nevada
Energy Technology Data Exchange (ETDEWEB)
Gertz, C.P.; Nelson, R.M. Jr.; Blanchard, M.B. [Department of Energy, Las Vegas, NV (United States); Cloke, P.L. [Science Applications International Corp., Las Vegas, NV (United States)
1994-12-31
The Yucca Mountain Site Characterization Project (YMP) involves a complex set of activities and issues. These include the Exploratory Studies Facility (ESF), site characterization surface-based testing, performance assessment, public outreach and information services, conceptual design of a potential repository, compliance with regulations, environmental issues, transportation of nuclear wastes, and systems engineering. Integration among the scientific and technical activities requires constant attention to keep work focused on determining the suitability of the site and on avoiding irretrievable loss of data. All activities must be conducted with due regard to quality assurance and safety and health. This paper provides a brief summary of the status of these activities as of December, 1993.
19. Certification and beyond DINI open access activities in Germany
CERN Document Server
CERN. Geneva; Scholze, Frank
2005-01-01
Local publication servers are common and at the same time highly fragmented in Germany. To bring them to greater success it is necessary to standardize further developments. DINI with its publication "Electronic Publishing in Higher Education" laid a foundation for a widespread introduction of general regulations and standards concerning electronic publishing and archiving of scientific documents in institutional repositories. The DINI-Certificate "Document and Publication Repositories" takes this a step further by clearly describing criteria, that will guarantee repositories to be set up and operated according to national standards and international developments. Repositories fulfilling these criteria may be awarded a certificate, testifying to their quality. The DINI certificate may also help their operators to market the institutional repository as a reliable service to support electronic publishing as well as self- archiving at their institution. In parallel to this quality of service activities DINI star...
20. The effect of human activity noise on the acoustic quality in open plan office
DEFF Research Database (Denmark)
Dehlbæk, Tania Stenholt; Jeong, Cheol-Ho; Brunskog, Jonas
2016-01-01
A disadvantage of open plan offices is the noise annoyance. Noise problems in open plan offices have been dealt with in several studies, and standards have been set up. Still, what has not been taken into account is the effect of human activity noise on acoustic conditions. In this study, measure...... D2,S have an impact on the variation in the activity noise. At 1 kHz, the technical background noise influences human activity noise positively. In both octave bands, the human activity noise level varies significantly with the office type, from a call center to a lawyer’s office....
1. Active-site properties of Phrixotrix railroad worm green and red bioluminescence-eliciting luciferases.
Science.gov (United States)
Viviani, V R; Arnoldi, F G C; Venkatesh, B; Neto, A J S; Ogawa, F G T; Oehlmeyer, A T L; Ohmiya, Y
2006-10-01
The luciferases of the railroad worm Phrixotrix (Coleoptera: Phengodidae) are the only beetle luciferases that naturally produce true red bioluminescence. Previously, we cloned the green- (PxGR) and red-emitting (PxRE) luciferases of railroad worms Phrixotrix viviani and P. hirtus[OLE1]. These luciferases were expressed and purified, and their active-site properties were determined. The red-emitting PxRE luciferase displays flash-like kinetics, whereas PxGR luciferase displays slow-type kinetics. The substrate affinities and catalytic efficiency of PxRE luciferase are also higher than those of PxGR luciferase. Fluorescence studies with 8-anilino-1-naphthalene sulfonic acid and 6-p-toluidino-2-naphthalene sulfonic acid showed that the PxRE luciferase luciferin-binding site is more polar than that of PxGR luciferase, and it is sensitive to guanidine. Mutagenesis and modelling studies suggest that several invariant residues in the putative luciferin-binding site of PxRE luciferase cannot interact with excited oxyluciferin. These results suggest that one portion of the luciferin-binding site of the red-emitting luciferase is tighter than that of PxGR luciferase, whereas the other portion could be more open and polar.
2. Open-loop GPS signal tracking at low elevation angles from a ground-based observation site
Science.gov (United States)
Beyerle, Georg; Zus, Florian
2016-04-01
For more than a decade space-based global navigation satellite system (GNSS) radio occultation (RO) observations are used by meteorological services world-wide for their numerical weather prediction models. In addition, climate studies increasingly rely on validated GNSS-RO data sets of atmospheric parameters. GNSS-RO profiles typically cover an altitude range from the boundary layer up to the upper stratosphere; their highest accuracy and precision, however, are attained at the tropopause level. In the lower troposphere, multipath ray propagation tend to induce signal amplitude and frequency fluctuations which lead to the development and implementation of open-loop signal tracking methods in GNSS-RO receiver firmwares. In open-loop mode the feed-back values for the carrier tracking loop are derived not from measured data, but from a Doppler frequency model which usually is extracted from an atmospheric climatology. In order to ensure that this receiver-internal parameter set, does not bias the carrier phase path observables, dual-channel open-loop GNSS-RO signal tracking was suggested. Following this proposal the ground-based "GLESER" (GPS low-elevation setting event recorder) campaign was established. Its objective was to disproof the existence of model-induced frequency biases using ground-based GPS observations at very low elevation angles. Between January and December 2014 about 2600 validated setting events, starting at geometric elevation angles of +2° and extending to -1°… - 1.5°, were recorded by the single frequency "OpenGPS" GPS receiver at a measurement site located close to Potsdam, Germany (52.3808°N, 13.0642°E). The study is based on the assumption that these ground-based observations may be used as proxies for space-based RO measurements, even if the latter occur on a one order of magnitude faster temporal scale. The "GLESER" data analysis shows that the open-loop Doppler model has negligible influence on the derived frequency profile
3. Photometric multi-site campaign on the open cluster NGC 884 I. Detection of the variable stars
CERN Document Server
Saesen, S; Pigulski, A; Aerts, C; Handler, G; Narwid, A; Fu, J N; Zhang, C; Jiang, X J; Vanautgaerden, J; Kopacki, G; Stȩślicki, M; Acke, B; Poretti, E; Uytterhoeven, K; Gielen, C; Østensen, R; De Meester, W; Reed, M D; Kołaczkowski, Z; Michalska, G; Schmidt, E; Yakut, K; Leitner, A; Kalomeni, B; Cherix, M; Spano, M; Prins, S; Van Helshoecht, V; Zima, W; Huygen, R; Vandenbussche, B; Lenz, P; Ladjal, D; Antolín, E Puga; Verhoelst, T; De Ridder, J; Niarchos, P; Liakos, A; Lorenz, D; Dehaes, S; Reyniers, M; Davignon, G; Kim, S -L; Kim, D H; Lee, Y -J; Lee, C -U; Kwon, J -H; Broeders, E; Van Winckel, H; Vanhollebeke, E; Waelkens, C; Raskin, G; Blom, Y; Eggen, J R; Degroote, P; Beck, P; Puschnig, J; Schmitzberger, L; Gelven, G A; Steininger, B; Blommaert, J; Drummond, R; Briquet, M; Debosscher, J
2010-01-01
CONTEXT: Recent progress in the seismic interpretation of field beta Cep stars has resulted in improvements of the physics in the stellar structure and evolution models of massive stars. Further asteroseismic constraints can be obtained from studying ensembles of stars in a young open cluster, which all have similar age, distance and chemical composition. AIMS: To improve our comprehension of the beta Cep stars, we studied the young open cluster NGC 884 to discover new B-type pulsators, besides the two known beta Cep stars, and other variable stars. METHODS: An extensive multi-site campaign was set up to gather accurate CCD photometry time series in four filters (U, B, V, I) of a field of NGC884. Fifteen different instruments collected almost 77500 CCD images in 1286 hours. The images were calibrated and reduced to transform the CCD frames into interpretable differential light curves. Various variability indicators and frequency analyses were applied to detect variable stars in the field. Absolute photometry ...
4. Annual variation in canopy openness, air temperature and humidity inthe understory of three forested sites in southern Bahia State, Brazil
Directory of Open Access Journals (Sweden)
2013-01-01
Full Text Available Aiming at contributing to the knowledge of physical factors affecting community structure in Atlantic Forest remnants of southern Bahia state, Brazil, we analyzed the annual variation in the understory microclimate of a hillside forest fragment in the ‘Reserva Particular do Patrimônio Natural Serra do Teimoso’ (RST and a rustic cacao agroforestry system (Cabruca, located nearby the RST. Canopy openness (CO, air temperature (Ta, air relative humidity (RH and vapor pressure deficit (VPD data were collected between April, 2005 and April, 2006 at the base (RSTB, 340 m and the top (RSTT, 640 m of the RST and at the Cabruca (CB, 250 m. Data of rainfall, Ta, RH and VPD were also collected in an open area (OA, 270 m. The highest rainfalls (> 100 mm occurred in November, 2005 and April, 2006, whereas October, 2005 was the driest month (< 20 mm. CO ranged between 2.5 % in the CB (April, 2006 and 7.7 % in the RST (October, 2005. Low rainfall in October, 2005 affected VPDmax in all sites. Those effects were more pronounced in OA, followed by CB, RSTB and RSTT. During the period of measurements, the values of Ta, RH and VPD in CB were closer to the values measured in OA than to the values measured inside the forest.
5. Differential active site loop conformations mediate promiscuous activities in the lactonase SsoPox.
Directory of Open Access Journals (Sweden)
Julien Hiblot
Full Text Available Enzymes are proficient catalysts that enable fast rates of Michaelis-complex formation, the chemical step and products release. These different steps may require different conformational states of the active site that have distinct binding properties. Moreover, the conformational flexibility of the active site mediates alternative, promiscuous functions. Here we focused on the lactonase SsoPox from Sulfolobus solfataricus. SsoPox is a native lactonase endowed with promiscuous phosphotriesterase activity. We identified a position in the active site loop (W263 that governs its flexibility, and thereby affects the substrate specificity of the enzyme. We isolated two different sets of substitutions at position 263 that induce two distinct conformational sampling of the active loop and characterized the structural and kinetic effects of these substitutions. These sets of mutations selectively and distinctly mediate the improvement of the promiscuous phosphotriesterase and oxo-lactonase activities of SsoPox by increasing active-site loop flexibility. These observations corroborate the idea that conformational diversity governs enzymatic promiscuity and is a key feature of protein evolvability.
6. An Active Site Water Network in the Plasminogen Activator Pla from Yersinia pestis
Energy Technology Data Exchange (ETDEWEB)
Eren, Elif; Murphy, Megan; Goguen, Jon; van den Berg, Bert (UMASS, MED)
2010-08-13
The plasminogen activator Pla from Yersinia pestis is an outer membrane protease (omptin) that is important for the virulence of plague. Here, we present the high-resolution crystal structure of wild-type, enzymatically active Pla at 1.9 {angstrom}. The structure shows a water molecule located between active site residues D84 and H208, which likely corresponds to the nucleophilic water. A number of other water molecules are present in the active site, linking residues important for enzymatic activity. The R211 sidechain in loop L4 is close to the nucleophilic water and possibly involved in the stabilization of the oxyanion intermediate. Subtle conformational changes of H208 result from the binding of lipopolysaccharide to the outside of the barrel, explaining the unusual dependence of omptins on lipopolysaccharide for activity. The Pla structure suggests a model for the interaction with plasminogen substrate and provides a more detailed understanding of the catalytic mechanism of omptin proteases.
7. Spatial, Hysteretic, and Adaptive Host-Guest Chemistry in a Metal-Organic Framework with Open Watson-Crick Sites.
Science.gov (United States)
Cai, Hong; Li, Mian; Lin, Xiao-Rong; Chen, Wei; Chen, Guang-Hui; Huang, Xiao-Chun; Li, Dan
2015-09-01
Biological and artificial molecules and assemblies capable of supramolecular recognition, especially those with nucleobase pairing, usually rely on autonomous or collective binding to function. Advanced site-specific recognition takes advantage of cooperative spatial effects, as in local folding in protein-DNA binding. Herein, we report a new nucleobase-tagged metal-organic framework (MOF), namely ZnBTCA (BTC=benzene-1,3,5-tricarboxyl, A=adenine), in which the exposed Watson-Crick faces of adenine residues are immobilized periodically on the interior crystalline surface. Systematic control experiments demonstrated the cooperation of the open Watson-Crick sites and spatial effects within the nanopores, and thermodynamic and kinetic studies revealed a hysteretic host-guest interaction attributed to mild chemisorption. We further exploited this behavior for adenine-thymine binding within the constrained pores, and a globally adaptive response of the MOF host was observed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
8. Active site loop conformation regulates promiscuous activity in a lactonase from Geobacillus kaustophilus HTA426.
Science.gov (United States)
Zhang, Yu; An, Jiao; Yang, Guang-Yu; Bai, Aixi; Zheng, Baisong; Lou, Zhiyong; Wu, Geng; Ye, Wei; Chen, Hai-Feng; Feng, Yan; Manco, Giuseppe
2015-01-01
Enzyme promiscuity is a prerequisite for fast divergent evolution of biocatalysts. A phosphotriesterase-like lactonase (PLL) from Geobacillus kaustophilus HTA426 (GkaP) exhibits main lactonase and promiscuous phosphotriesterase activities. To understand its catalytic and evolutionary mechanisms, we investigated a "hot spot" in the active site by saturation mutagenesis as well as X-ray crystallographic analyses. We found that position 99 in the active site was involved in substrate discrimination. One mutant, Y99L, exhibited 11-fold improvement over wild-type in reactivity (kcat/Km) toward the phosphotriesterase substrate ethyl-paraoxon, but showed 15-fold decrease toward the lactonase substrate δ-decanolactone, resulting in a 157-fold inversion of the substrate specificity. Structural analysis of Y99L revealed that the mutation causes a ∼6.6 Å outward shift of adjacent loop 7, which may cause increased flexibility of the active site and facilitate accommodation and/or catalysis of organophosphate substrate. This study provides for the PLL family an example of how the evolutionary route from promiscuity to specificity can derive from very few mutations, which promotes alteration in the conformational adjustment of the active site loops, in turn draws the capacity of substrate binding and activity.
9. Active site loop conformation regulates promiscuous activity in a lactonase from Geobacillus kaustophilus HTA426.
Directory of Open Access Journals (Sweden)
Yu Zhang
Full Text Available Enzyme promiscuity is a prerequisite for fast divergent evolution of biocatalysts. A phosphotriesterase-like lactonase (PLL from Geobacillus kaustophilus HTA426 (GkaP exhibits main lactonase and promiscuous phosphotriesterase activities. To understand its catalytic and evolutionary mechanisms, we investigated a "hot spot" in the active site by saturation mutagenesis as well as X-ray crystallographic analyses. We found that position 99 in the active site was involved in substrate discrimination. One mutant, Y99L, exhibited 11-fold improvement over wild-type in reactivity (kcat/Km toward the phosphotriesterase substrate ethyl-paraoxon, but showed 15-fold decrease toward the lactonase substrate δ-decanolactone, resulting in a 157-fold inversion of the substrate specificity. Structural analysis of Y99L revealed that the mutation causes a ∼6.6 Å outward shift of adjacent loop 7, which may cause increased flexibility of the active site and facilitate accommodation and/or catalysis of organophosphate substrate. This study provides for the PLL family an example of how the evolutionary route from promiscuity to specificity can derive from very few mutations, which promotes alteration in the conformational adjustment of the active site loops, in turn draws the capacity of substrate binding and activity.
10. Administrator Interest is Perceived to Encourage Faculty and Librarian Involvement in Open Access Activities
OpenAIRE
Eamon C. Tewell
2014-01-01
A Review of: Reinsfelder, T.L., & Anderson, J.A. (2013). Observations and perceptions of academic administrator influence on open access initiatives. Journal of Academic Librarianship, 39(6): 481-487. http://dx.doi.org/10.1016/j.acalib.2013.08.014 Abstract Objective – To better understand the roles and influence of senior-level academic administrators, such as provosts, on open access (OA) activities at the institutional level, including whether librarians perform these activit...
11. Using internal coupling activities to enhance the effectiveness of open innovation
DEFF Research Database (Denmark)
Burcharth, Ana Luiza de Araújo; Knudsen, Mette Præst; Søndergaard, Helle Alsted
firms adopt a number of coupling activities that provide employees with time, autonomy and empowerment to conduct their work. The paper therefore contributes to the innovation management literature by developing the concept of internal coupling activities, testing these on a set of open innovation...
12. Allosteric site-mediated active site inhibition of PBP2a using Quercetin 3-O-rutinoside and its combination.
Science.gov (United States)
Rani, Nidhi; Vijayakumar, Saravanan; P T V, Lakshmi; Arunachalam, Annamalai
2016-08-01
Recent crystallographic study revealed the involvement of allosteric site in active site inhibition of penicillin binding protein (PBP2a), where one molecule of Ceftaroline (Cef) binds to the allosteric site of PBP2a and paved way for the other molecule (Cef) to bind at the active site. Though Cef has the potency to inhibit the PBP2a, its adverse side effects are of major concern. Previous studies have reported the antibacterial property of Quercetin derivatives, a group of natural compounds. Hence, the present study aims to evaluate the effect of Quercetin 3-o-rutinoside (Rut) in allosteric site-mediated active site inhibition of PBP2a. The molecular docking studies between allosteric site and ligands (Rut, Que, and Cef) revealed a better binding efficiency (G-score) of Rut (-7.790318) and Cef (-6.194946) with respect to Que (-5.079284). Molecular dynamic (MD) simulation studies showed significant changes at the active site in the presence of ligands (Rut and Cef) at allosteric site. Four different combinations of Rut and Cef were docked and their G-scores ranged between -6.320 and -8.623. MD studies revealed the stability of the key residue (Ser403) with Rut being at both sites, compared to other complexes. Morphological analysis through electron microscopy confirmed that combination of Rut and Cefixime was able to disturb the bacterial cell membrane in a similar fashion to that of Rut and Cefixime alone. The results of this study indicate that the affinity of Rut at both sites were equally good, with further validations Rut could be considered as an alternative for inhibiting MRSA growth.
13. Active control of counter-rotating open rotor interior noise in a Dornier 728 experimental aircraft
Science.gov (United States)
Haase, Thomas; Unruh, Oliver; Algermissen, Stephan; Pohl, Martin
2016-08-01
The fuel consumption of future civil aircraft needs to be reduced because of the CO2 restrictions declared by the European Union. A consequent lightweight design and a new engine concept called counter-rotating open rotor are seen as key technologies in the attempt to reach this ambitious goals. Bearing in mind that counter-rotating open rotor engines emit very high sound pressures at low frequencies and that lightweight structures have a poor transmission loss in the lower frequency range, these key technologies raise new questions in regard to acoustic passenger comfort. One of the promising solutions for the reduction of sound pressure levels inside the aircraft cabin are active sound and vibration systems. So far, active concepts have rarely been investigated for a counter-rotating open rotor pressure excitation on complex airframe structures. Hence, the state of the art is augmented by the preliminary study presented in this paper. The study shows how an active vibration control system can influence the sound transmission of counter-rotating open rotor noise through a complex airframe structure into the cabin. Furthermore, open questions on the way towards the realisation of an active control system are addressed. In this phase, an active feedforward control system is investigated in a fully equipped Dornier 728 experimental prototype aircraft. In particular, the sound transmission through the airframe, the coupling of classical actuators (inertial and piezoelectric patch actuators) into the structure and the performance of the active vibration control system with different error sensors are investigated. It can be shown that the active control system achieves a reduction up to 5 dB at several counter-rotating open rotor frequencies but also that a better performance could be achieved through further optimisations.
14. Moving targets: Promoting physical activity in public spaces via open streets in the US.
Science.gov (United States)
Hipp, J Aaron; Bird, Alyssa; van Bakergem, Margaret; Yarnall, Elizabeth
2016-10-20
Popularity of Open Streets, temporarily opening streets to communities and closing streets to vehicles, in the US has recently surged. As of January 2016, 122 cities have hosted an Open Streets program. Even with this great expansion, the sustainability of Open Streets remains a challenge in many cities and overall Open Streets in the US differ from their successful counterparts in Central and South America. Between summer 2015 and winter 2016, we reviewed the websites and social media of the 122 identified programs and interviewed 32 unique Open Streets programs. Websites and social media were reviewed for program initiation, number of Open Streets days, length of routes, duration of program, and reported participation. Interview questions focused on barriers and facilitators of expanding Open Streets and specific questioning regarding local evaluation activities. All interviews were transcribed verbatim and analyzed with constant comparative methodology. Over three-quarters of US Open Streets programs have been initiated since 2010, with median frequency of one time per year, 4h per date, and 5000-9999 participants. Seventy-seven percent of program routes are under 5km in length. Success of programs was measured by enthusiasm, attendance, social media, survey metrics, and sustainability. Thirteen of 32 program organizers expressed interest in expanding their programs to 12 dates per year, but noted consistent barriers to expansion including funding, permitting, and branding. Though many cities now host Open Streets programs, their ability to effect public health remains limited with few program dates per year. Coordinated efforts, especially around funding, permitting, and branding may assist in expanding program dates. Copyright © 2016 Elsevier Inc. All rights reserved.
15. Active site conformational dynamics in human uridine phosphorylase 1.
Directory of Open Access Journals (Sweden)
Tarmo P Roosild
Full Text Available Uridine phosphorylase (UPP is a central enzyme in the pyrimidine salvage pathway, catalyzing the reversible phosphorolysis of uridine to uracil and ribose-1-phosphate. Human UPP activity has been a focus of cancer research due to its role in activating fluoropyrimidine nucleoside chemotherapeutic agents such as 5-fluorouracil (5-FU and capecitabine. Additionally, specific molecular inhibitors of this enzyme have been found to raise endogenous uridine concentrations, which can produce a cytoprotective effect on normal tissues exposed to these drugs. Here we report the structure of hUPP1 bound to 5-FU at 2.3 A resolution. Analysis of this structure reveals new insights as to the conformational motions the enzyme undergoes in the course of substrate binding and catalysis. The dimeric enzyme is capable of a large hinge motion between its two domains, facilitating ligand exchange and explaining observed cooperativity between the two active sites in binding phosphate-bearing substrates. Further, a loop toward the back end of the uracil binding pocket is shown to flexibly adjust to the varying chemistry of different compounds through an "induced-fit" association mechanism that was not observed in earlier hUPP1 structures. The details surrounding these dynamic aspects of hUPP1 structure and function provide unexplored avenues to develop novel inhibitors of this protein with improved specificity and increased affinity. Given the recent emergence of new roles for uridine as a neuron protective compound in ischemia and degenerative diseases, such as Alzheimer's and Parkinson's, inhibitors of hUPP1 with greater efficacy, which are able to boost cellular uridine levels without adverse side-effects, may have a wide range of therapeutic applications.
16. Hazardous Material Storage Facilities and Sites - WASTE_SOLID_ACTIVE_PERMITTED_IDEM_IN: Active Permitted Solid Waste Sites in Indiana (Indiana Department of Environmental Management, Point Shapefile)
Data.gov (United States)
NSGIC GIS Inventory (aka Ramona) — WASTE_SOLID_ACTIVE_PERMITTED_IDEM_IN is a point shapefile that contains active permitted solid waste site locations in Indiana, provided by personnel of Indiana...
17. Modelling Active Faults in Probabilistic Seismic Hazard Analysis (PSHA) with OpenQuake: Definition, Design and Experience
Science.gov (United States)
Weatherill, Graeme; Garcia, Julio; Poggi, Valerio; Chen, Yen-Shin; Pagani, Marco
2016-04-01
The Global Earthquake Model (GEM) has, since its inception in 2009, made many contributions to the practice of seismic hazard modeling in different regions of the globe. The OpenQuake-engine (hereafter referred to simply as OpenQuake), GEM's open-source software for calculation of earthquake hazard and risk, has found application in many countries, spanning a diversity of tectonic environments. GEM itself has produced a database of national and regional seismic hazard models, harmonizing into OpenQuake's own definition the varied seismogenic sources found therein. The characterization of active faults in probabilistic seismic hazard analysis (PSHA) is at the centre of this process, motivating many of the developments in OpenQuake and presenting hazard modellers with the challenge of reconciling seismological, geological and geodetic information for the different regions of the world. Faced with these challenges, and from the experience gained in the process of harmonizing existing models of seismic hazard, four critical issues are addressed. The challenge GEM has faced in the development of software is how to define a representation of an active fault (both in terms of geometry and earthquake behaviour) that is sufficiently flexible to adapt to different tectonic conditions and levels of data completeness. By exploring the different fault typologies supported by OpenQuake we illustrate how seismic hazard calculations can, and do, take into account complexities such as geometrical irregularity of faults in the prediction of ground motion, highlighting some of the potential pitfalls and inconsistencies that can arise. This exploration leads to the second main challenge in active fault modeling, what elements of the fault source model impact most upon the hazard at a site, and when does this matter? Through a series of sensitivity studies we show how different configurations of fault geometry, and the corresponding characterisation of near-fault phenomena (including
18. Active site - a site of binding of affinity inhibitors in baker's yeast inorganic pyrophosphatase
Energy Technology Data Exchange (ETDEWEB)
Svyato, I.E.; Sklyankina, V.A.; Avaeva, S.M.
1986-03-20
The interaction of the enzyme-substrate complex with methyl phosphate, O-phosphoethanolamine, O-phosphopropanolamine, N-acetylphosphoserine, and phosphoglyolic acid, as well as pyrophosphatase, modified by monoesters of phosphoric acid, with pyrophosphate and tripolyphosphate, was investigated. It was shown that the enzyme containing the substrate in the active site does not react with monophosphates, but modified pyrophosphatase entirely retains the ability to bind polyanions to the regulatory site. It is concluded that the inactivation of baker's yeast inorganic pyrophosphatase by monoesters of phosphoric acid, which are affinity inhibitors of it, is the result of modification of the active site of the enzyme.
19. Lithological Conditions at the Box Canyon Site: Results of Drilling, Coring and Open Borehole Measurements 1995-1997 Data Report
Energy Technology Data Exchange (ETDEWEB)
Burgess, D.; Faybishenko, B.; Holland, P.; Knutson, C.; Mesa, M.; Sisson, B.
1998-09-01
DOE faces the remediation of several contaminated sites in unsaturated fractured basalt where organic and radioactive wastes have migrated downward through fracture pathways that are difficult, if not impossible, to detect. Perched water zones located above zones of low permeability (massive basalt) create a complicated system of hydraulic baffles. Because of these large scale heterogeneities, the characterization of the lithology of the rock and the geometry of the subsurface fracture pattern is a crucial step in the development of a conceptual model of fluid flow and chemical transport, and eventually the design of a remediation system. The purpose of this data report is to compile and document the results of drilling and lithological studies conducted in open boreholes at the Box Canyon site. Lithological templates are included for each well and contain data such as drilling date, drilling method, logging method, well coordinates, Lithological log, gamma measurements, caliper measurements, core run and recovery depth, vesicular intervals, single fracture depths and descriptions, fracture zone depth and descriptions, and general comments about the borehole lithology. The lithological features were mapped for each borehole. The gamma and caliper measurements are presented as separate plots using greater resolution. Color core photos and core descriptions are also included. TV logging was used to map the lithology of the boreholes that were not cored (E, R, and T wells). This information will be further used to create a comprehensive lithological model of the subsurface. The TV logging of cored wells was viewed to compare the resolution and accuracy of TV logging to core logging. The TV logging method accurately showed large scale features such as zones of vesicularity, large fractures, fracture zones, rubble zones, and massive basalt zones, but it was difficult to detect hairline fractures, fracture orientation, and mineralization of fractures. Also, all depth
20. Cloning and characterization of a novel nuclease from shrimp hepatopancreas, and prediction of its active site.
Science.gov (United States)
Wang, W Y; Liaw, S H; Liao, T H
2000-03-15
Approximately 95% of the amino acid sequence of a shrimp (Penaeus japonicus) nuclease was derived from protease-digested peptides. A 1461-base cDNA for the nuclease was amplified and sequenced with degenerate primers based on the amino acid sequence and then specific primers by 3' and 5' RACE (rapid amplification of cDNA ends). It contains an open reading frame encoding a putative 21-residue signal peptide and a 381-residue mature protein. The N-terminus of the enzyme is pyroglutamate, deduced from composition and matrix-assisted laser desorption ionization-time-of-flight MS analyses, and confirmed by a glutamine residue in the cDNA sequence. The enzyme has 11 Cys residues, forming five intramolecular disulphides. The eleventh Cys residue was linked to a thiol compound with an estimated molecular mass of between 500 and 700 Da. A sequence similarity search revealed no homologous proteins but residues 205-255 shared a conserved active-site motif within a distinct group of nucleases. His(211) in this conserved motif was shown to be very important in catalysis by site-specific modification with (14)C-labelled iodoacetate. The shrimp nuclease, previously designated DNase I, does indeed possess a low level of hydrolytic activity towards RNA in the presence of Mg(2+) and Ca(2+). The conservation of functionally important residues during distant evolution might imply that the catalytic mechanisms are similar in these nucleases, which should be classified in one subfamily. Finally, an active-site structure for shrimp nuclease was proposed on the basis of published structural data and the results of mutational and biochemical analyses of Serratia nuclease.
1. Protection of open-metal V(III) sites and their associated CO₂/CH₄/N₂/O₂/H₂O adsorption properties in mesoporous V-MOFs.
Science.gov (United States)
Yang, Jiangfeng; Wang, Yong; Li, Libo; Zhang, Zhuoming; Li, Jinping
2015-10-15
2. Active versus passive radon monitoring at the Yucca Mountain site
Energy Technology Data Exchange (ETDEWEB)
Griffin, M.D. [Science Applications International Corp., Las Vegas, NV (United States)
1994-12-31
Federal Regulations have mandated that a baseline assessment for the Yucca Mountain Site be performed. This includes the detection and monitoring of specific radionuclides present at the site. These radionuclides include radon 222, a decay progeny of naturally occurring uranium. Two radon monitoring systems are utilized at the Yucca Mountain site to detect ambient levels of radon. The first is a passive time integrated system, and the second is a continuous radon monitoring (CRM) system.
3. Conformation analysis of a surface loop that controls active site access in the GH11 xylanase A from Bacillus subtilis.
Science.gov (United States)
Vieira, Davi Serradella; Ward, Richard John
2012-04-01
Xylanases (EC 3.2.1.8 endo-1,4-glycosyl hydrolase) catalyze the hydrolysis of xylan, an abundant hemicellulose of plant cell walls. Access to the catalytic site of GH11 xylanases is regulated by movement of a short β-hairpin, the so-called thumb region, which can adopt open or closed conformations. A crystallographic study has shown that the D11F/R122D mutant of the GH11 xylanase A from Bacillus subtilis (BsXA) displays a stable "open" conformation, and here we report a molecular dynamics simulation study comparing this mutant with the native enzyme over a range of temperatures. The mutant open conformation was stable at 300 and 328 K, however it showed a transition to the closed state at 338 K. Analysis of dihedral angles identified thumb region residues Y113 and T123 as key hinge points which determine the open-closed transition at 338 K. Although the D11F/R122D mutations result in a reduction in local inter-intramolecular hydrogen bonding, the global energies of the open and closed conformations in the native enzyme are equivalent, suggesting that the two conformations are equally accessible. These results indicate that the thumb region shows a broader degree of energetically permissible conformations which regulate the access to the active site region. The R122D mutation contributes to the stability of the open conformation, but is not essential for thumb dynamics, i.e., the wild type enzyme can also adapt to the open conformation.
4. Open Augmented Reality Standards： Current Activities in Standards- Development Organizations%Open Augmented Reality Standards: Current Activities in Standards- Development Organizations
Institute of Scientific and Technical Information of China (English)
Christine Perey
2012-01-01
Augmented reality (AR) has emerged from research laboratories and is now being accepted in other domains as an attractive way of visualizing information. Before AR can be used in the mass market, there are a number of obstacles that need to be overcome. Several of these can be overcome by adopting open standards. A global grassroots community seeking open, interoperable AR content and experiences began to take shape in early 2010. This community is working collaboratively to reduce the barriers to the flow of data from content provider to AR end user. Standards development organizations and industry groups that provide open interfaces for AR meet regularly to provide updates, identify complementary work, and seek harmonization. The community also identifies deployer and implementer needs, communicates requirements, and discusses emerging challenges that could be resolved with standards. In this article, we describe current activities in international standards-development organizations. We summarize the AR standards gap analysis and shed light on special considerations for using standards in mobile AR.
5. Expression of adhesion and activation molecules on lymphocytes during open-heart surgery with cardiopulmonary bypass
DEFF Research Database (Denmark)
Toft, P; Tønnesen, Else Kirstine; Zülow, I
1997-01-01
Open-heart surgery with cardiopulmonary bypass (CPB) and abdominal surgery are associated with lymphocytopenia. We measured a panel of adhesion and activation molecules on lymphocytes to clarify possible association of CPB with increased expression of these molecules. Eight patients undergoing open......-heart surgery and eight with abdominal surgery were studied. The adhesion molecules CD11a/CD18 (LFA-1_, CD11c/CD18 and CD44 and the activation molecules CD25, CD69, CD71 and MHCII were measured, using monoclonal antibodies and flow cytometry. Lymphocytopenia was observed during CPB and for some hours after both...... open-heart and abdominal surgery. The proportion of CD11a/CD18-positive lymphocytes rose from 67.6 +/- 8% to 86.4 +/- 3% after aortic declamping (p
6. Initial Open Trial of a Computerized Behavioral Activation Treatment for Depression
Science.gov (United States)
Spates, C. Richard; Kalata, Alyssa H.; Ozeki, Satoshi; Stanton, Cory E.; Peters, Sofia
2013-01-01
This article presents preliminary findings from use of a novel computer program that implements an evidence-based psychological intervention to treat depression based on behavioral activation (BA) therapy. The program is titled “Building a Meaningful Life Through Behavioral Activation”. The findings derive from an open trial with moderate to…
7. Induction of sperm activation in open and closed thelycum penaeoid shrimps
NARCIS (Netherlands)
Alfaro Montoya, J.; Munoz, N.; Vargas, M.; Komen, J.
2003-01-01
A modified egg water (EW) technique for in vitro induction of sperm activation was applied to Trachypenaeus byrdi, Xiphopenaeus riveti (closed thelycum shrimps), and Litopenaeus occidentalis (open thelycum) from a tropical estuary, Golfo de Nicoya, Costa Rica. The study was designed to investigate t
8. Initial Open Trial of a Computerized Behavioral Activation Treatment for Depression
Science.gov (United States)
Spates, C. Richard; Kalata, Alyssa H.; Ozeki, Satoshi; Stanton, Cory E.; Peters, Sofia
2013-01-01
This article presents preliminary findings from use of a novel computer program that implements an evidence-based psychological intervention to treat depression based on behavioral activation (BA) therapy. The program is titled “Building a Meaningful Life Through Behavioral Activation”. The findings derive from an open trial with moderate to…
9. The AAM-API: An Open Source Active Appearance Model Implementation
DEFF Research Database (Denmark)
Stegmann, Mikkel Bille
2003-01-01
This paper presents a public domain implementation of the Active Appearance Model framework and gives examples using it for segmentation and analysis of medical images. The software is open source, designed with efficiency in mind, and has been thoroughly tested and evaluated in several medical a...
10. Adult Learning Open University Determinants study (ALOUD): physical activity associated with study success
NARCIS (Netherlands)
Gijselaers, Jérôme; De Groot, Renate; Kirschner, Paul A.
2013-01-01
Gijselaers, H. J. M., De Groot, R. H. M., & Kirschner, P. A. (2013, 23 May). Adult Learning Open University Determinants study (ALOUD): physical activity associated with study success. Poster presentation at the annual meeting of the International Society for Behaviour on Nutrition and Physical Acti
11. Heart Rate Variability in Nonlinear Rats with Different Orientation and Exploratory Activity in the Open Field.
Science.gov (United States)
Kur'yanova, E V; Teplyi, D L; Zhukova, Yu D; Zhukovina, N V
2015-12-01
The basic behavioral activity of nonlinear rats was evaluated from the sum of crossed peripheral and central squares and peripheral and central rearing postures in the open fi eld test. This index was low (30 episodes). Male rats with high score of orientation and exploratory activity were characterized by higher indexes of total heart rate variability than rats with low or intermediate activity. Specimens with a greater contribution of VLF waves into the total power spectrum of heart rate variability were shown to dominate among the rats with high behavioral activity. Our results are consistent with the notions of a suprasegmental nature of VLF waves.
12. Highly selective adsorption of ethylene over ethane in a MOF featuring the combination of open metal site and π-complexation
NARCIS (Netherlands)
Zhang, Y.; Li, B.; Krishna, R.; Wu, Z.; Ma, D.; Shi, Z.; Pham, T.; Forrest, K.; Space, B.; Ma, S.
2015-01-01
The introduction of the combination of open metal site (OMS) and π-complexation into MOF has led to very high ethylene-ethane adsorption selectivity at 318 K, as illustrated in the context of MIL-101-Cr-SO3Ag. The interactions with ethylene from both OMS and π-complexation in MIL-101-Cr-SO3Ag have
13. Incidence and risk factors for surgical site infection after open reduction and internal fixation of tibial plateau fracture: A systematic review and meta-analysis.
Science.gov (United States)
Shao, Jiashen; Chang, Hengrui; Zhu, Yanbin; Chen, Wei; Zheng, Zhanle; Zhang, Huixin; Zhang, Yingze
2017-05-01
This study aimed to quantitatively summarize the risk factors associated with surgical site infection after open reduction and internal fixation of tibial plateau fracture. Medline, Embase, CNKI, Wanfang database and Cochrane central database were searched for relevant original studies from database inception to October 2016. Eligible studies had to meet quality assessment criteria according to the Newcastle-Ottawa Scale, and had to evaluate the risk factors for surgical site infection after open reduction and internal fixation of tibial plateau fracture. Stata 11.0 software was used for this meta-analysis. Eight studies involving 2214 cases of tibial plateau fracture treated by open reduction and internal fixation and 219 cases of surgical site infection were included in this meta-analysis. The following parameters were identified as significant risk factors for surgical site infection after open reduction and internal fixation of tibial plateau fracture (p internal fixation of tibial plateau fracture. Surgeons should be cognizant of these risks and give relevant preoperative advice. Copyright © 2017. Published by Elsevier Ltd.
14. Highly selective adsorption of ethylene over ethane in a MOF featuring the combination of open metal site and π-complexation
NARCIS (Netherlands)
Zhang, Y.; Li, B.; Krishna, R.; Wu, Z.; Ma, D.; Shi, Z.; Pham, T.; Forrest, K.; Space, B.; Ma, S.
2015-01-01
The introduction of the combination of open metal site (OMS) and π-complexation into MOF has led to very high ethylene-ethane adsorption selectivity at 318 K, as illustrated in the context of MIL-101-Cr-SO3Ag. The interactions with ethylene from both OMS and π-complexation in MIL-101-Cr-SO3Ag have b
15. Efficient, regioselective ring-opening of activated aziridine-2-carboxylates with [18F]fluoride
DEFF Research Database (Denmark)
Schjøth-Eskesen, Christina; Hansen, Paul Robert; Kjær, Andreas;
2015-01-01
Aziridines can undergo a range of ring-opening reactions with nucleophiles. The regio- and stereochemistry of the products depend on the substituents on the aziridine. Aziridine ring-opening reactions have rarely been used in radiosynthesis. Herein we report the ring opening of activated aziridin...
16. Impact of biocrust succession on water retention and repellency on open-cast lignite mining sites under reclamation in Lower Lusatia, NE-Germany
Science.gov (United States)
Gypser, Stella; Fischer, Thomas; Lange, Philipp; Veste, Maik
2016-04-01
Mining activities can strongly affect ecosystem properties by destruction of naturally developed soils and removal of vegetation. The unstructured substrates show high bulk densities, compaction, low water infiltration rates, reduced water holding capacities and higher susceptibility to wind and water erosion. In the initial stage of the ecosystem development, the post-mining sites are open areas without or with a low cover of higher vegetation. It is well-known that biocrusts are able to colonize the soil surface under such extreme conditions without human support and affect soil hydrological processes such as water infiltration, run-off or re-distribution. Investigations were conducted on two former lignite open-cast mining sites, an artificial sand dune on the reclaimed watershed Welzow "Neuer Lugteich" and a reforestation area in Schlabendorf (Brandenburg, north-east Germany). The aim was to relate the hydrological characteristics of the topsoil to successional stages of biological soil crusts on reclaimed soils and their influence on repellency index and water holding capacity compared to pure mining substrate. Our study emphasized the influence of changing successional stages and species composition of biological soil crusts, forming a small-scale crust pattern, on water repellency and retention on sandy soils in temperate climate. Different successional stages of soil crusts were identified from initial scattered green algae crusts, dominated by Zygogonium spec. and Ulothrix spec., and more developed soil crusts containing mosses such as Ceratodon purpureus and Polytrichum piliferum. Lichens of the Genus Cladonia were more pronouncedly contributed to biocrusts at later and mature stages of development. The repellency index on the one hand increased due to the cross-linking of sand particles by the filamentous green algae Zygogonium spec. which resulted in clogging of pores, and on the other hand decreased with the occurrence of moss plants due to absorption
17. Monoclonal antibody against the active site of caeruloplasmin and the ELISA system detecting active caeruloplasmin.
Science.gov (United States)
Hiyamuta, S; Ito, K
1994-04-01
Serum caeruloplasmin deficiency is a characteristic biochemical abnormality found in patients with Wilson's disease, but the mechanism of this disease is unknown. Although the phenylenediamine oxidase activity of serum caeruloplasmin is markedly low in patients with Wilson's disease, mRNA of caeruloplasmin exists to some extent. To investigate the deficiency of caeruloplasmin oxidase activity in Wilson's disease, we generated 14 monoclonal antibodies (MAbs) and selected ID1, which had the strongest reactivity, and ID2, which had neutralizing ability. We also established a system to measure active caeruloplasmin specifically using these MAbs. These MAbs and the system will be useful tools in analyzing the active site of caeruloplasmin in patients with Wilson's disease.
18. Open-ended versus guided laboratory activities: Impact on students' beliefs about experimental physics
CERN Document Server
Wilcox, Bethany R
2016-01-01
Improving students' understanding of the nature of experimental physics is often an explicit or implicit goal of undergraduate laboratory physics courses. However, lab activities in traditional lab courses are typically characterized by highly structured, guided labs that often do not require or encourage students to engage authentically in the process of experimental physics. Alternatively, open-ended laboratory activities can provide a more authentic learning environment by, for example, allowing students to exercise greater autonomy in what and how physical phenomena are investigated. Engaging in authentic practices may be a critical part of improving students' beliefs around the nature of experimental physics. Here, we investigate the impact of open-ended activities in undergraduate lab courses on students' epistemologies and expectations about the nature of experimental physics, as well as their confidence and affect, as measured by the Colorado Learning Attitudes about Science Survey for Experimental Ph...
19. Open-ended versus guided laboratory activities:Impact on students' beliefs about experimental physics
Science.gov (United States)
Wilcox, Bethany R.; Lewandowski, H. J.
2016-12-01
Improving students' understanding of the nature of experimental physics is often an explicit or implicit goal of undergraduate laboratory physics courses. However, lab activities in traditional lab courses are typically characterized by highly structured, guided labs that often do not require or encourage students to engage authentically in the process of experimental physics. Alternatively, open-ended laboratory activities can provide a more authentic learning environment by, for example, allowing students to exercise greater autonomy in what and how physical phenomena are investigated. Engaging in authentic practices may be a critical part of improving students' beliefs around the nature of experimental physics. Here, we investigate the impact of open-ended activities in undergraduate lab courses on students' epistemologies and expectations about the nature of experimental physics, as well as their confidence and affect, as measured by the Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS). Using a national data set of student responses to the E-CLASS, we find that the inclusion of some open-ended lab activities in a lab course correlates with more expertlike postinstruction responses relative to courses that include only traditional guided lab activities. This finding holds when examining postinstruction E-CLASS scores while controlling for the variance associated with preinstruction scores, course level, student major, and student gender.
20. Human population and activities in Forsmark. Site description
Energy Technology Data Exchange (ETDEWEB)
Miliander, Sofia; Punakivi, Mari; Kylaekorpi, Lasse; Rydgren, Bernt [SwedPower AB, Stockholm (Sweden)
2004-12-01
The Swedish Nuclear Fuel and Waste Management Co (SKB) is in the process of selecting a safe and environmentally acceptable location for a deep repository of radioactive waste. Two alternative locations are under investigation. These are Forsmark, Oesthammars kommun (kommun = municipality) and Simpevarp/Laxemar, Oskarshamns kommun. SKB has expressed the importance of describing the humans and their activities in these areas and therefore has this synthesis concerning the human population in Forsmark been produced.The description is a statistical synthesis, mainly based upon statistical data from SCB (Statistics Sweden) that has been collected, processed and analysed. The statistical data has not been verified through site inspections and interviews. When using statistical data, it is advisable to note that the data becomes more unreliable if the areas are small, with small populations.The data in this description is essential for future evaluations of the impact on the environment and its human population (Environmental Impact Assessments). The data is also important when modelling the potential flows of radio nuclides and calculating the risk of exposure in future safety assessments.The actual area for the study is in this report called 'the Forsmark area', an area of 19.5 km{sup 2} near Forsmark nuclear power plant. The land use in the Forsmark area differs notably from the land use in Uppsala laen (laen = county). Only 0.04% of the total area is developed (built-up) compared to 4.9% in Uppsala laen and only 4% is agricultural land compared to 25% in the county. Furthermore, there are far more forest, wetlands and water areas in the Forsmark area. The forest area represents as much as 72.5% of the total area.The Forsmark area is uninhabited, and its surroundings are very sparsely populated. In 2002, the population density in Forsmark was 1.8 inhabitants per square kilometre, which was 24 times lower than in Uppsala laen. The population density in the
1. Synthesis and characterization of 18F-labeled active site inhibited factor VII (ASIS)
DEFF Research Database (Denmark)
Erlandsson, Maria; Nielsen, Carsten Haagen; Jeppesen, Troels Elmer
2015-01-01
Activated factor VII blocked in the active site with Phe-Phe-Arg-chloromethyl ketone (active site inhibited factor VII (ASIS)) is a 50-kDa protein that binds with high affinity to its receptor, tissue factor (TF). TF is a transmembrane glycoprotein that plays an important role in, for example, th...
2. Chronic Toxoplasma gondii in Nurr1-null heterozygous mice exacerbates elevated open field activity.
Directory of Open Access Journals (Sweden)
Jeffrey B Eells
Full Text Available Latent infection with Toxoplasma gondii is common in humans (approximately 30% of the global population and is a significant risk factor for schizophrenia. Since prevalence of T. gondii infection is far greater than prevalence of schizophrenia (0.5-1%, genetic risk factors are likely also necessary to contribute to schizophrenia. To test this concept in an animal model, Nurr1-null heterozygous (+/- mice and wild-type (+/+ mice were evaluate using an emergence test, activity in an open field and with a novel object, response to bobcat urine and prepulse inhibition of the acoustic startle response (PPI prior to and 6 weeks after infection with T. gondii. In the emergence test, T. gondii infection significantly decreased the amount of time spent in the cylinder. Toxoplasma gondii infection significantly elevated open field activity in both +/+ and +/- mice but this increase was significantly exacerbated in +/- mice. T. gondii infection reduced PPI in male +/- mice but this was not statistically significant. Aversion to bobcat urine was abolished by T. gondii infection in +/+ mice. In female +/- mice, aversion to bobcat urine remained after T. gondii infection while the male +/- mice showed no aversion to bobcat urine. Antibody titers of infected mice were a critical variable associated with changes in open field activity, such that an inverted U shaped relationship existed between antibody titers and the percent change in open field activity with a significant increase in activity at low and medium antibody titers but no effect at high antibody titers. These data demonstrate that the Nurr1 +/- genotype predisposes mice to T. gondii-induced alterations in behaviors that involve dopamine neurotransmission and are associated with symptoms of schizophrenia. We propose that these alterations in murine behavior were due to further exacerbation of the altered dopamine neurotransmission in Nurr1 +/- mice.
3. Oxygen Activation at the Active Site of a Fungal Lytic Polysaccharide Monooxygenase.
Science.gov (United States)
O'Dell, William B; Agarwal, Pratul K; Meilleur, Flora
2017-01-16
Lytic polysaccharide monooxygenases have attracted vast attention owing to their abilities to disrupt glycosidic bonds via oxidation instead of hydrolysis and to enhance enzymatic digestion of recalcitrant substrates including chitin and cellulose. We have determined high-resolution X-ray crystal structures of an enzyme from Neurospora crassa in the resting state and of a copper(II) dioxo intermediate complex formed in the absence of substrate. X-ray crystal structures also revealed "pre-bound" molecular oxygen adjacent to the active site. An examination of protonation states enabled by neutron crystallography and density functional theory calculations identified a role for a conserved histidine in promoting oxygen activation. These results provide a new structural description of oxygen activation by substrate free lytic polysaccharide monooxygenases and provide insights that can be extended to reactivity in the enzyme-substrate complex. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
4. Administrator Interest is Perceived to Encourage Faculty and Librarian Involvement in Open Access Activities
Directory of Open Access Journals (Sweden)
Eamon C. Tewell
2014-09-01
5. Effect of the Northern Sea Route Opening to the Shipping Activities at Malacca Straits
Directory of Open Access Journals (Sweden)
N.S.F. Abdul Rahman
2014-12-01
Full Text Available The opening of the Northern Sea Route as an alternative route for transporting cargoes between the Far East and Europe seems highly acceptable by shipping companies due to the great saving in fuel consumption, bunker cost, operating cost, emissions and journey time. This situation will not only affect the maritime business activity in the Straits of Malacca but also, the Malaysian economy in different perspectives when the vessels sail via the Suez Canal and the Indian Ocean are expected to decrease. The objective of this study is to analyse the implication in the opening of the Northern Sea Route on Maritime Sector of the Malaysian economy by using PESTEL analysis. The main scope is focusing more on the Malacca Straits shipping activity by using a number of parameters that have been obtained from Port Klang and Port Klang Authority through a set of questionnaires and interview sessions with industrial experts.
6. The role of actively open-minded thinking in information acquisition, accuracy, and calibration
Directory of Open Access Journals (Sweden)
Uriel Haran
2013-05-01
Full Text Available Errors in estimating and forecasting often result from the failure to collect and consider enough relevant information. We examine whether attributes associated with persistence in information acquisition can predict performance in an estimation task. We focus on actively open-minded thinking (AOT, need for cognition, grit, and the tendency to maximize or satisfice when making decisions. In three studies, participants made estimates and predictions of uncertain quantities, with varying levels of control over the amount of information they could collect before estimating. Only AOT predicted performance. This relationship was mediated by information acquisition: AOT predicted the tendency to collect information, and information acquisition predicted performance. To the extent that available information is predictive of future outcomes, actively open-minded thinkers are more likely than others to make accurate forecasts.
7. An Investigation into Social Learning Activities by Practitioners in Open Educational Practices
Directory of Open Access Journals (Sweden)
Antoine Van den Beemt
2014-09-01
Full Text Available By investigating how educational practitioners participate in activities around open educational practices (OEP, this paper aims at contributing to an understanding of open practices and how these practitioners learn to use OEP. Our research is guided by the following hypothesis: Different social configurations support a variety of social learning activities. The social configuration of OEPs is investigated by an operationalization into the dimensions (1 practice, (2 domain, (3 collective identity, and (4 organization. The results show how practitioners of six different OEPs learn, while acting and collaborating through a combination of offline and online networks. The findings of our study lead to practical implications on how to support participation in OEP, and thereby stimulate learning in (online networks of OEP.
8. Studies on the biotin-binding site of avidin. Lysine residues involved in the active site.
Science.gov (United States)
Gitlin, G; Bayer, E A; Wilchek, M
1987-01-01
Egg-white avidin was treated with 1-fluoro-2,4-dinitrobenzene. Modification of an average of one lysine residue per avidin subunit caused the complete loss of biotin binding. Tryptic peptides obtained from the 2,4-dinitrophenylated avidin were fractionated by reversed-phase h.p.l.c. Three peptides contained the 2,4-dinitrophenyl group. Amino acid analysis revealed that lysine residues 45, 94 and 111 are modified and probably comprise part of the biotin-binding site. PMID:3109401
9. Studies on the biotin-binding site of avidin. Lysine residues involved in the active site.
OpenAIRE
Gitlin, G; Bayer, E A; Wilchek, M
1987-01-01
Egg-white avidin was treated with 1-fluoro-2,4-dinitrobenzene. Modification of an average of one lysine residue per avidin subunit caused the complete loss of biotin binding. Tryptic peptides obtained from the 2,4-dinitrophenylated avidin were fractionated by reversed-phase h.p.l.c. Three peptides contained the 2,4-dinitrophenyl group. Amino acid analysis revealed that lysine residues 45, 94 and 111 are modified and probably comprise part of the biotin-binding site.
10. Preliminary siting activities for new waste handling facilities at the Idaho National Engineering Laboratory
Energy Technology Data Exchange (ETDEWEB)
Taylor, D.D.; Hoskinson, R.L.; Kingsford, C.O.; Ball, L.W.
1994-09-01
The Idaho Waste Processing Facility, the Mixed and Low-Level Waste Treatment Facility, and the Mixed and Low-Level Waste Disposal Facility are new waste treatment, storage, and disposal facilities that have been proposed at the Idaho National Engineering Laboratory (INEL). A prime consideration in planning for such facilities is the selection of a site. Since spring of 1992, waste management personnel at the INEL have been involved in activities directed to this end. These activities have resulted in the (a) identification of generic siting criteria, considered applicable to either treatment or disposal facilities for the purpose of preliminary site evaluations and comparisons, (b) selection of six candidate locations for siting,and (c) site-specific characterization of candidate sites relative to selected siting criteria. This report describes the information gathered in the above three categories for the six candidate sites. However, a single, preferred site has not yet been identified. Such a determination requires an overall, composite ranking of the candidate sites, which accounts for the fact that the sites under consideration have different advantages and disadvantages, that no single site is superior to all the others in all the siting criteria, and that the criteria should be assigned different weighing factors depending on whether a site is to host a treatment or a disposal facility. Stakeholder input should now be solicited to help guide the final selection. This input will include (a) siting issues not already identified in the siting, work to date, and (b) relative importances of the individual siting criteria. Final site selection will not be completed until stakeholder input (from the State of Idaho, regulatory agencies, the public, etc.) in the above areas has been obtained and a strategy has been developed to make a composite ranking of all candidate sites that accounts for all the siting criteria.
11. 78 FR 33908 - Commercial Wind Lease Issuance and Site Assessment Activities on the Atlantic Outer Continental...
Science.gov (United States)
2013-06-05
... renewable energy leases and subsequent site characterization activities (geophysical, geotechnical, archaeological, and biological surveys needed to develop specific project proposals on those leases) in an... from leasing, site characterization, and site assessment in and around the Call Area (76 FR 51391)....
12. The Impact of Entry and Competition by Open Source Software on Innovation Activity
DEFF Research Database (Denmark)
Schröder, Philipp J.H.; Bitzer, Jürgen
2006-01-01
This chapter presents the stylized facts of open source software innovation and provides empirical evidence on the impact of increased competition by OSS on the innovative activity in the software industry. Furthermore, we introduce a simple formal model that captures the innovation impact of OSS...... entry by examining a change in market structure from monopoly to duopoly under the assumption that software producers compete in technology rather than price or quantities. The chapter identifies a pro-innovative effect of OSS competition....
13. The role of actively open-minded thinking in information acquisition, accuracy, and calibration
OpenAIRE
Uriel Haran; Ilana Ritov; MELLERS, BARBARA A
2013-01-01
Errors in estimating and forecasting often result from the failure to collect and consider enough relevant information. We examine whether attributes associated with persistence in information acquisition can predict performance in an estimation task. We focus on actively open-minded thinking (AOT), need for cognition, grit, and the tendency to maximize or satisfice when making decisions. In three studies, participants made estimates and predictions of uncertain quantities, with varying level...
14. Are nest sites actively chosen? Testing a common assumption for three non-resource limited birds
Science.gov (United States)
Goodenough, A. E.; Elliot, S. L.; Hart, A. G.
2009-09-01
Many widely-accepted ecological concepts are simplified assumptions about complex situations that remain largely untested. One example is the assumption that nest-building species choose nest sites actively when they are not resource limited. This assumption has seen little direct empirical testing: most studies on nest-site selection simply assume that sites are chosen actively (and seek explanations for such behaviour) without considering that sites may be selected randomly. We used 15 years of data from a nestbox scheme in the UK to test the assumption of active nest-site choice in three cavity-nesting bird species that differ in breeding and migratory strategy: blue tit ( Cyanistes caeruleus), great tit ( Parus major) and pied flycatcher ( Ficedula hypoleuca). Nest-site selection was non-random (implying active nest-site choice) for blue and great tits, but not for pied flycatchers. We also considered the relative importance of year-specific and site-specific factors in determining occupation of nest sites. Site-specific factors were more important than year-specific factors for the tit species, while the reverse was true for pied flycatchers. Our results show that nest-site selection, in birds at least, is not always the result of active choice, such that choice should not be assumed automatically in studies of nesting behaviour. We use this example to highlight the need to test key ecological assumptions empirically, and the importance of doing so across taxa rather than for single "model" species.
15. Early Site Permit Demonstration Program: Recommendations for communication activities and public participation in the Early Site Permit Demonstration Program
Energy Technology Data Exchange (ETDEWEB)
1993-01-27
On October 24, 1992, President Bush signed into law the National Energy Policy Act of 1992. The bill is a sweeping, comprehensive overhaul of the Nations energy laws, the first in more than a decade. Among other provisions, the National Energy Policy Act reforms the licensing process for new nuclear power plants by adopting a new approach developed by the US Nuclear Regulatory Commission (NRC) in 1989, and upheld in court in 1992. The NRC 10 CFR Part 52 rule is a three-step process that guarantees public participation at each step. The steps are: early site permit approval; standard design certifications; and, combined construction/operating licenses for nuclear power reactors. Licensing reform increases an organizations ability to respond to future baseload electricity generation needs with less financial risk for ratepayers and the organization. Costly delays can be avoided because design, safety and siting issues will be resolved before a company starts to build a plant. Specifically, early site permit approval allows for site suitability and acceptability issues to be addressed prior to an organizations commitment to build a plant. Responsibility for site-specific activities, including communications and public participation, rests with those organizations selected to try out early site approval. This plan has been prepared to assist those companies (referred to as sponsoring organizations) in planning their communications and public involvement programs. It provides research findings, information and recommendations to be used by organizations as a resource and starting point in developing their own plans.
16. Human population and activities at Simpevarp. Site description
Energy Technology Data Exchange (ETDEWEB)
Miliander, Sofia; Punakivi, Mari; Kylaekorpi, Lasse; Rydgren, Bernt [SwedPower AB, Stockholm (Sweden)
2004-12-01
The Swedish Nuclear Fuel and Waste Management Co (SKB) is in the process of selecting a safe and environmentally acceptable location for a deep repository of radioactive waste. Two alternative locations are under investigation. These are Forsmark, Oesthammars kommun (kommun = municipality) and Simpevarp/Laxemar, Oskarshamns kommun. SKB has expressed the importance of describing the humans and their activities in these areas and therefore has this synthesis concerning the human population in Forsmark been produced. The description is a statistical synthesis, mainly based upon statistical data from SCB (Statistics Sweden) that has been collected, processed and analysed. The statistical data has not been verified through site inspections and interviews. When using statistical data, it is advisable to note that the data becomes more unreliable if the areas are small, with small populations. The data in this description is essential for future evaluations of the impact on the environment and its human population (environmental impacts assessments). The data is also important when modelling the potential flows of radio nuclides and calculating the risk of exposure in future safety assessments. The actual area for the study is in this report called 'the Simpevarp area', an area of 127.0 km{sup 2} near Oskarshamn nuclear power plant. The land use in Simpevarp area differs notably from the land use in Kalmar laen. The forest area is far more dominating in Simpevarp area than in Kalmar laen and it represents as much as 89% compared to 63% of the total area. Only 4.4% of the area is arable land compared to 11.6% in Kalmar laen and only 0.3% is of other type (wetlands, bare rock, quarries, pites etc) compared to 15.6% in the county. The main observation is that Simpevarp area is a sparsely populated area located in a relatively lightly populated county. In 2002, the population density was 7.4 inhabitants/km{sup 2}, three times lower than in Kalmar laen. The
17. Human population and activities at Simpevarp. Site description
Energy Technology Data Exchange (ETDEWEB)
Miliander, Sofia; Punakivi, Mari; Kylaekorpi, Lasse; Rydgren, Bernt [SwedPower AB, Stockholm (Sweden)
2004-12-01
The Swedish Nuclear Fuel and Waste Management Co (SKB) is in the process of selecting a safe and environmentally acceptable location for a deep repository of radioactive waste. Two alternative locations are under investigation. These are Forsmark, Oesthammars kommun (kommun = municipality) and Simpevarp/Laxemar, Oskarshamns kommun. SKB has expressed the importance of describing the humans and their activities in these areas and therefore has this synthesis concerning the human population in Forsmark been produced. The description is a statistical synthesis, mainly based upon statistical data from SCB (Statistics Sweden) that has been collected, processed and analysed. The statistical data has not been verified through site inspections and interviews. When using statistical data, it is advisable to note that the data becomes more unreliable if the areas are small, with small populations. The data in this description is essential for future evaluations of the impact on the environment and its human population (environmental impacts assessments). The data is also important when modelling the potential flows of radio nuclides and calculating the risk of exposure in future safety assessments. The actual area for the study is in this report called 'the Simpevarp area', an area of 127.0 km{sup 2} near Oskarshamn nuclear power plant. The land use in Simpevarp area differs notably from the land use in Kalmar laen. The forest area is far more dominating in Simpevarp area than in Kalmar laen and it represents as much as 89% compared to 63% of the total area. Only 4.4% of the area is arable land compared to 11.6% in Kalmar laen and only 0.3% is of other type (wetlands, bare rock, quarries, pites etc) compared to 15.6% in the county. The main observation is that Simpevarp area is a sparsely populated area located in a relatively lightly populated county. In 2002, the population density was 7.4 inhabitants/km{sup 2}, three times lower than in Kalmar laen. The
18. Synthetic Active Site Model of the [NiFeSe] Hydrogenase.
Science.gov (United States)
Wombwell, Claire; Reisner, Erwin
2015-05-26
A dinuclear synthetic model of the [NiFeSe] hydrogenase active site and a structural, spectroscopic and electrochemical analysis of this complex is reported. [NiFe('S2Se2')(CO)3] (H2'S2Se2' = 1,2-bis(2-thiabutyl-3,3-dimethyl-4-selenol)benzene) has been synthesized by reacting the nickel selenolate complex [Ni('S2Se2')] with [Fe(CO)3bda] (bda = benzylideneacetone). X-ray crystal structure analysis confirms that [NiFe('S2Se2')(CO)3] mimics the key structural features of the enzyme active site, including a doubly bridged heterobimetallic nickel and iron center with a selenolate terminally coordinated to the nickel center. Comparison of [NiFe('S2Se2')(CO)3] with the previously reported thiolate analogue [NiFe('S4')(CO)3] (H2'S4' = H2xbsms = 1,2-bis(4-mercapto-3,3-dimethyl-2-thiabutyl)benzene) showed that the selenolate groups in [NiFe('S2Se2')(CO)3] give lower carbonyl stretching frequencies in the IR spectrum. Electrochemical studies of [NiFe('S2Se2')(CO)3] and [NiFe('S4')(CO)3] demonstrated that both complexes do not operate as homogenous H2 evolution catalysts, but are precursors to a solid deposit on an electrode surface for H2 evolution catalysis in organic and aqueous solution. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
19. Multiscale Modeling of the Active Site of [Fe] Hydrogenase: The H2 Binding Site in Open and Closed Protein Conformations
DEFF Research Database (Denmark)
Hedegård, Erik D.; Kongsted, Jacob; Ryde, Ulf
2015-01-01
multiscale modeling appears to be necessary, especially to obtain reliable distances between CH-H4MPT+ and the dihydrogen (H2) or hydride (H¢) ligand in the FeGP cofactor. Inclusion of the full protein is further important for the relative energies of the two intermediates 2 and 3. We finally find...
20. Multiscale modeling of the active site of [Fe] hydrogenase: the H₂ binding site in open and closed protein conformations.
Science.gov (United States)
Hedegård, Erik Donovan; Kongsted, Jacob; Ryde, Ulf
2015-05-18
A series of QM/MM optimizations of the full protein of [Fe] hydrogenase were performed. The FeGP cofactor has been optimized in the water-bound resting state (1), with a side-on bound dihydrogen (2), or as a hydride intermediate (3). For inclusion of H4MPT in the closed structure, advanced multiscale modeling appears to be necessary, especially to obtain reliable distances between CH-H4MPT(+) and the dihydrogen (H2) or hydride (H(-)) ligand in the FeGP cofactor. Inclusion of the full protein is further important for the relative energies of the two intermediates 2 and 3. We finally find that hydride transfer from 3 has a significantly higher barrier than found in previous studies neglecting the full protein environment.
1. OpenNFT: An open-source Python/Matlab framework for real-time fMRI neurofeedback training based on activity, connectivity and multivariate pattern analysis.
Science.gov (United States)
Koush, Yury; Ashburner, John; Prilepin, Evgeny; Sladky, Ronald; Zeidman, Peter; Bibikov, Sergei; Scharnowski, Frank; Nikonorov, Artem; De Ville, Dimitri Van
2017-08-01
Neurofeedback based on real-time functional magnetic resonance imaging (rt-fMRI) is a novel and rapidly developing research field. It allows for training of voluntary control over localized brain activity and connectivity and has demonstrated promising clinical applications. Because of the rapid technical developments of MRI techniques and the availability of high-performance computing, new methodological advances in rt-fMRI neurofeedback become possible. Here we outline the core components of a novel open-source neurofeedback framework, termed Open NeuroFeedback Training (OpenNFT), which efficiently integrates these new developments. This framework is implemented using Python and Matlab source code to allow for diverse functionality, high modularity, and rapid extendibility of the software depending on the user's needs. In addition, it provides an easy interface to the functionality of Statistical Parametric Mapping (SPM) that is also open-source and one of the most widely used fMRI data analysis software. We demonstrate the functionality of our new framework by describing case studies that include neurofeedback protocols based on brain activity levels, effective connectivity models, and pattern classification approaches. This open-source initiative provides a suitable framework to actively engage in the development of novel neurofeedback approaches, so that local methodological developments can be easily made accessible to a wider range of users. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
2. Insights into an intriguing gas sorption mechanism in a polar metal–organic framework with open-metal sites and narrow channels
KAUST Repository
Forrest, Katherine A.
2014-01-01
Simulations of H2 and CO2 sorption were performed in the metal-organic framework (MOF), [Cu(Me-4py-trz-ia)]. This MOF was recently shown experimentally to exhibit high uptake for H2 and CO2 sorption and this was reproduced and elucidated through the simulations performed herein. Consistent with experiment, the theoretical isosteric heat of adsorption, Qst, values were nearly constant across all loadings for both sorbates. The simulations revealed that sorption directly onto the open-metal sites was not observed in this MOF, ostensibly a consequence of the low partial positive charges of the Cu2+ ions as determined through electronic structure calculations. Sorption was primarily observed between adjacent carboxylate oxygen atoms (site 1) and between nearby methyl groups (site 2) of the organic linkers. In addition, saturation of the most energetically favorable sites (site 1) is possible only after filling a nearby site (site 2) first due to the MOF topology. This suggests that the lack of dependence on loading for the Qst is due to the concurrent filling of sites 1 and 2, leading to an observed average Qst value. © 2014 the Partner Organisations.
3. Insights into an intriguing gas sorption mechanism in a polar metal-organic framework with open-metal sites and narrow channels.
Science.gov (United States)
Forrest, Katherine A; Pham, Tony; McLaughlin, Keith; Hogan, Adam; Space, Brian
2014-07-14
Simulations of H2 and CO2 sorption were performed in the metal-organic framework (MOF), [Cu(Me-4py-trz-ia)]. This MOF was recently shown experimentally to exhibit high uptake for H2 and CO2 sorption and this was reproduced and elucidated through the simulations performed herein. Consistent with experiment, the theoretical isosteric heat of adsorption, Q(st), values were nearly constant across all loadings for both sorbates. The simulations revealed that sorption directly onto the open-metal sites was not observed in this MOF, ostensibly a consequence of the low partial positive charges of the Cu(2+) ions as determined through electronic structure calculations. Sorption was primarily observed between adjacent carboxylate oxygen atoms (site 1) and between nearby methyl groups (site 2) of the organic linkers. In addition, saturation of the most energetically favorable sites (site 1) is possible only after filling a nearby site (site 2) first due to the MOF topology. This suggests that the lack of dependence on loading for the Q(st) is due to the concurrent filling of sites 1 and 2, leading to an observed average Q(st) value.
4. Sorption of H2 to open metal sites in a metal-organic framework: a symmetry-adapted perturbation theory analysis.
Science.gov (United States)
Goings, Joshua J; Ohlsen, Suzanna M; Blaisdell, Kara M; Schofield, Daniel P
2014-09-04
Metal-organic frameworks (MOFs) show considerable promise as materials for gas storage and separation. Many MOF structures have open metal sites, which allow for coordination of gas molecules to the metal centers. In this work, we use coupled-cluster and symmetry-adapted perturbation theory to probe the interaction between hydrogen gas and unsaturated metal sites in mimic structures based on the MOF HKUST-1. The interactions are of a mixed electrostatic/dispersive nature, with the relative magnitudes of these components dependent on the metal center. The strongest binding was found for magnesium- and zinc-containing MOFs, with an overall interaction energy of -4.5 kcal mol(-1).
5. Freely dissolved concentrations and sediment-water activity ratios of PCDD/Fs and PCBs in the open Baltic Sea.
Science.gov (United States)
Cornelissen, Gerard; Wiberg, Karin; Broman, Dag; Arp, Hans Peter H; Persson, Ylva; Sundqvist, Kristina; Jonsson, Per
2008-12-01
Aqueous concentrations of polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs) as well as polychlorinated biphenyls (PCBs) in the open sea have heretofore been measured by filtering and extracting large amounts of water. Measurement of freely dissolved concentrations with this technique is difficult because of corrections for sorption to dissolved organic matter. In this study we use a novel, more economic technique using equilibrium passive samplers consisting of 17-microm thin polyoxymethylene (POM-17), capable of measuring freely dissolved aqueous concentrations (Cw) in pristine (i.e., background) locations. POM-17 was employed in an extensive field campaign at five stations in the open Baltic sea to obtain Cw at two depths (1 m above the seafloor and 25 m below the surface). Median Cw in the overlying water was 2.3 pg toxic equivalents (TEQ)/m3 PCDD/Fs and 15 pg/L sum 7-PCB, with generally less than a factor two variation among sites and depths. Also freely dissolved concentrations of native compounds in the surface sediment porewater (C(PW)) were determined in laboratory batch experiments. The data were used to derive sediment-water activity ratios, which indicate the diffusive flux direction. It was found that the PCDD/Fs and PCBs were in close equilibrium between the sediment porewater and the overlying water. Comparison of C(PW) with total sediment concentrations indicated that more than 90% of the compounds were sorbed to sedimentary black carbon.
6. 76 FR 24871 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites
Science.gov (United States)
2011-05-03
... Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites AGENCY: Department of... from eligible active uranium and thorium processing site licensees for reimbursement under Title X of...). Title X requires DOE to reimburse eligible uranium and thorium licensees for certain costs...
7. 76 FR 30696 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites
Science.gov (United States)
2011-05-26
... Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites AGENCY: Department of... eligible active uranium and thorium processing site licensees for reimbursement under Title X of the Energy... requires DOE to reimburse eligible uranium and thorium licensees for certain costs of...
8. Identification of Active Edge Sites for Electrochemical H2 Evolution from MoS2 Nanocatalysts
DEFF Research Database (Denmark)
Jaramillo, Thomas; Jørgensen, Kristina Pilt; Bonde, Jacob;
2007-01-01
The identification of the active sites in heterogeneous catalysis requires a combination of surface sensitive methods and reactivity studies. We determined the active site for hydrogen evolution, a reaction catalyzed by precious metals, on nanoparticulate molybdenum disulfide (MoS2) by atomically...
9. Evaluation of physiological and biochemical responses of two rice (Oryza sativa L.) cultivars to ambient air pollution using open top chambers at a rural site in India.
Science.gov (United States)
2008-12-15
Air pollutant concentrations are rising in India, causing potential threats to crop production. As air pollutants are known to interfere with physiological processes, this study was conducted to assess the relative responses of physiological and biochemical characteristics of two cultivars of rice (Oryza sativa L. cv. Saurabh 950 and NDR 97) leading to variable yield responses. Twelve hour monitoring of ambient concentrations of SO2, NO2 and O3 in filtered chambers (FCs), non-filtered chambers (NFCs) and open plots (OPs) showed that O3 was the main pollutant at the experimental site. Ozone concentrations often exceeded 40 ppb during anthesis but not during the vegetative growth period. Photosynthetic rate (Ps), stomatal conductance (g(s)) and Fv/Fm ratio, superoxide dismutase (SOD) and peroxidase (POD) activities and photosynthetic pigments, ascorbic acid, total phenolics and protein contents were assessed at different developmental stages and yield of grains were quantified. Lipid peroxidation, SOD and POD activities, ascorbic acid and total phenolics were higher, whereas Ps, g(s), Fv/Fm ratio and contents of protein and photosynthetic pigment were lower in plants of NFCs as compared to FCs. Yield decreased significantly in both cultivars grown in NFCs. NDR 97 showed less reductions in physiological characteristics, photosynthetic pigments and protein, but a greater increase in the antioxidative defense system as compared to Saurabh 950. Yield reduction was higher in NDR 97 than in Saurabh 950. This suggested that NDR 97 utilized more photosynthate in maintaining the metabolic machinery against O3 stress leading to lower translocation of photosynthate to reproductive parts. The study concluded that under natural field conditions, physiological and biochemical responses of plants varied with pollutant concentrations leading to different translocation strategies in plants, modifying their yield responses. NDR 97, a fast growing and high yielding cultivar was more
10. The structure of amylosucrase from Deinococcus radiodurans has an unusual open active-site topology
DEFF Research Database (Denmark)
Skov, Lars K; Pizzut-Serin, Sandra; Remaud-Simeon, Magali;
2013-01-01
Amylosucrases (ASes) catalyze the formation of an α-1,4-glucosidic linkage by transferring a glucosyl unit from sucrose onto an acceptor α-1,4-glucan. To date, several ligand-bound crystal structures of wild-type and mutant ASes from Neisseria polysaccharea and Deinococcus geothermalis have been ...
11. The zinc binuclear cluster activator AlcR is able to bind to single sites but requires multiple repeated sites for synergistic activation of the alcA gene in Aspergillus nidulans.
Science.gov (United States)
Panozzo, C; Capuano, V; Fillinger, S; Felenbok, B
1997-09-01
The alcA gene which is part of the recently identified ethanol regulon, is one of the most strongly inducible genes in Aspergillus nidulans. Its transcriptional activation is mediated by the AlcR transactivator which contains a DNA-binding domain belonging to the C6 zinc binuclear cluster family. AlcR differs from the other members of this family by several features, the most striking characteristic being its binding to both symmetric and asymmetric DNA sites with the same apparent affinity. However, AlcR is also able to bind to a single site with high affinity, suggesting that unlike the other C6 proteins, AlcR binds as a monomer. In this report, we show that AlcR targets, to be functional in vivo, have to be organized as inverted or direct repeats. In addition, we show a strong synergistic activation of alcA transcription in which the number and the position of the AlcR-binding sites are crucial. The fact that the AlcR unit for in vitro binding is a single site whereas the in vivo functional unit is a repeat opens the question of the mechanism of the strong alcA transactivation. These results show that AlcR displays both in vitro and in vivo a new range of binding specificity and provides a novel example in the C6 zinc cluster protein family.
12. Active Tectonic Research for Seismic Safety Evaluation of Long-Line Engineering Sites in China
Institute of Scientific and Technical Information of China (English)
Ran Yongkang; Chen Lichun
2005-01-01
Long-line engineering sites usually have to pass through active tectonics, so the research of active tectonics is of great importance to seismic safety evaluation of this sort of site. In the paper, basing on the summarization and analysis of the requirements for seismic safety evaluation of long-line engineering site and the status quo of active tectonics research, we propose the focal points of active tectonics research for seismic safety evaluation of long-line engineering sites, including the research contents, technical targets and routes, and the submission of the achievements, etc. Finally, we make a preliminary analysis and discussion about the problems existing in the present-day active tectonics research for seismic safety evaluation of long-line engineering sites.
13. Studies on the biotin-binding site of avidin. Tryptophan residues involved in the active site.
OpenAIRE
Gitlin, G; Bayer, E A; Wilchek, M
1988-01-01
Egg-white avidin was modified with the tryptophan-specific reagent 2-hydroxy-5-nitrobenzyl bromide. The complete loss of biotin-binding activity was achieved upon modification of an average of one tryptophan residue per avidin subunit. The identity of the modified residues was determined by isolating the relevant tryptic and chymotryptic peptides from CNBr-cleaved avidin fragments. The results demonstrate that Trp-70 and Trp-110 are modified in approximately equivalent proportions. It is beli...
14. Crystal structure of Pedobacter heparinus heparin lyase Hep III with the active site in a deep cleft.
Science.gov (United States)
Hashimoto, Wataru; Maruyama, Yukie; Nakamichi, Yusuke; Mikami, Bunzo; Murata, Kousaku
2014-02-04
Pedobacter heparinus (formerly known as Flavobacterium heparinum) is a typical glycosaminoglycan-degrading bacterium that produces three heparin lyases, Hep I, Hep II, and Hep III, which act on heparins with 1,4-glycoside bonds between uronate and amino sugar residues. Being different from Hep I and Hep II, Hep III is specific for heparan sulfate. Here we describe the crystal structure of Hep III with the active site located in a deep cleft. The X-ray crystallographic structure of Hep III was determined at 2.20 Å resolution using single-wavelength anomalous diffraction. This enzyme comprised an N-terminal α/α-barrel domain and a C-terminal antiparallel β-sheet domain as its basic scaffold. Overall structures of Hep II and Hep III were similar, although Hep III exhibited an open form compared with the closed form of Hep II. Superimposition of Hep III and heparin tetrasaccharide-bound Hep II suggested that an active site of Hep III was located in the deep cleft at the interface between its two domains. Three mutants (N240A, Y294F, and H424A) with mutations at the active site had significantly reduced enzyme activity. This is the first report of the structure-function relationship of P. heparinus Hep III.
15. Predicting the activation states of the muscles governing upper esophageal sphincter relaxation and opening.
Science.gov (United States)
Omari, Taher I; Jones, Corinne A; Hammer, Michael J; Cock, Charles; Dinning, Philip; Wiklendt, Lukasz; Costa, Marcello; McCulloch, Timothy M
2016-03-15
The swallowing muscles that influence upper esophageal sphincter (UES) opening are centrally controlled and modulated by sensory information. Activation and deactivation of neural inputs to these muscles, including the intrinsic cricopharyngeus (CP) and extrinsic submental (SM) muscles, results in their mechanical activation or deactivation, which changes the diameter of the lumen, alters the intraluminal pressure, and ultimately reduces or promotes flow of content. By measuring the changes in diameter, using intraluminal impedance, and the concurrent changes in intraluminal pressure, it is possible to determine when the muscles are passively or actively relaxing or contracting. From these "mechanical states" of the muscle, the neural inputs driving the specific motor behaviors of the UES can be inferred. In this study we compared predictions of UES mechanical states directly with the activity measured by electromyography (EMG). In eight subjects, pharyngeal pressure and impedance were recorded in parallel with CP- and SM-EMG activity. UES pressure and impedance swallow profiles correlated with the CP-EMG and SM-EMG recordings, respectively. Eight UES muscle states were determined by using the gradient of pressure and impedance with respect to time. Guided by the level and gradient change of EMG activity, mechanical states successfully predicted the activity of the CP muscle and SM muscle independently. Mechanical state predictions revealed patterns consistent with the known neural inputs activating the different muscles during swallowing. Derivation of "activation state" maps may allow better physiological and pathophysiological interpretations of UES function.
16. K sup + channel openers activate brain sulfonylurea-sensitive K sup + channels and block neurosecretion
Energy Technology Data Exchange (ETDEWEB)
Schmid-Antomarchi, H.; Amoroso, S.; Fosset, M.; Lazdunski, M. (Centre National de la Recherche Scientifique, Valbonne (France))
1990-05-01
Vascular K{sup +} channel openers such as cromakalim, nicorandil, and pinacidil potently stimulate {sup 86}Rb{sup +} efflux from slices of substantia nigra. This {sup 86}Rb{sup +} efflux is blocked by antidiabetic sulfonylureas, which are known to be potent and specific blockers of ATP-regulated K{sup +} channels in pancreatic beta cells, cardiac cells, and smooth muscle cells. K{sub 0.5}, the half-maximal effect of the enantiomer ({minus})-cromakalim, is as low as 10 nM, whereas K{sub 0.5} for nicorandil is 100 nM. These two compounds appear to have a much higher affinity for nerve cells than for smooth muscle cells. Openers of sulfonylurea-sensitive K{sup +} channels lead to inhibition of {gamma}-aminobutyric acid release. There is an excellent relationship between potency to activate {sup 86}Rb{sup +} efflux and potency to inhibit neurotransmitter release.
17. Protection of active implant electronics with organosilicon open air plasma coating for plastic overmolding
Directory of Open Access Journals (Sweden)
Zeppenfeld Matthias
2016-09-01
Full Text Available To overcome challenges for manufacturing of modern smart medical plastic parts by injection molding, e.g. for active implants, the optimization of the interface between electronics and the polymer component concerning adhesion and diffusion behavior is crucial. Our results indicate that a nano-sized SiOxCyHz layer formed by plasma-enhanced chemical vapour deposition (PE-CVD via open air atmospheric pressure plasma jet (APPJ and by use of a hexamthyldisiloxane (HMDSO precursor can form a non-corrosive, anti-permeable and biocompatible coating. Due to the open air character of the APPJ process an inline coating before overmolding could be an easy applicable method and a promising advancement.
18. Blogs and Social Network Sites as Activity Systems: Exploring Adult Informal Learning Process through Activity Theory Framework
Science.gov (United States)
Heo, Gyeong Mi; Lee, Romee
2013-01-01
This paper uses an Activity Theory framework to explore adult user activities and informal learning processes as reflected in their blogs and social network sites (SNS). Using the assumption that a web-based space is an activity system in which learning occurs, typical features of the components were investigated and each activity system then…
19. Diagnosis of abnormal patterns in multivariate microclimate monitoring: a case study of an open-air archaeological site in Pompeii (Italy).
Science.gov (United States)
Merello, Paloma; García-Diego, Fernando-Juan; Zarzo, Manuel
2014-08-01
Chemometrics has been applied successfully since the 1990s for the multivariate statistical control of industrial processes. A new area of interest for these tools is the microclimatic monitoring of cultural heritage. Sensors record climatic parameters over time and statistical data analysis is performed to obtain valuable information for preventive conservation. A case study of an open-air archaeological site is presented here. A set of 26 temperature and relative humidity data-loggers was installed in four rooms of Ariadne's house (Pompeii). If climatic values are recorded versus time at different positions, the resulting data structure is equivalent to records of physical parameters registered at several points of a continuous chemical process. However, there is an important difference in this case: continuous processes are controlled to reach a steady state, whilst open-air sites undergo tremendous fluctuations. Although data from continuous processes are usually column-centred prior to applying principal components analysis, it turned out that another pre-treatment (row-centred data) was more convenient for the interpretation of components and to identify abnormal patterns. The detection of typical trajectories was more straightforward by dividing the whole monitored period into several sub-periods, because the marked climatic fluctuations throughout the year affect the correlation structures. The proposed statistical methodology is of interest for the microclimatic monitoring of cultural heritage, particularly in the case of open-air or semi-confined archaeological sites. Copyright © 2014 Elsevier B.V. All rights reserved.
20. Role of active site conformational changes in photocycle activation of the AppA BLUF photoreceptor.
Science.gov (United States)
Goyal, Puja; Hammes-Schiffer, Sharon
2017-02-14
Blue light using flavin adenine dinucleotide (BLUF) proteins are essential for the light regulation of a variety of physiologically important processes and serve as a prototype for photoinduced proton-coupled electron transfer (PCET). Free-energy simulations elucidate the active site conformations in the AppA (activation of photopigment and puc expression) BLUF domain before and following photoexcitation. The free-energy profile for interconversion between conformations with either Trp104 or Met106 closer to the flavin, denoted Trpin/Metout and Trpout/Metin, reveals that both conformations are sampled on the ground state, with the former thermodynamically favorable by ∼3 kcal/mol. These results are consistent with the experimental observation of both conformations. To analyze the proton relay from Tyr21 to the flavin via Gln63, the free-energy profiles for Gln63 rotation were calculated on the ground state, the locally excited state of the flavin, and the charge-transfer state associated with electron transfer from Tyr21 to the flavin. For the Trpin/Metout conformation, the hydrogen-bonding pattern conducive to the proton relay is not thermodynamically favorable on the ground state but becomes more favorable, corresponding to approximately half of the configurations sampled, on the locally excited state. The calculated energy gaps between the locally excited and charge-transfer states suggest that electron transfer from Tyr21 to the flavin is more facile for configurations conducive to proton transfer. When the active site conformation is not conducive to PCET from Tyr21, Trp104 can directly compete with Tyr21 for electron transfer to the flavin through a nonproductive pathway, impeding the signaling efficiency.
1. Assessment of activation products in the Savannah River Site environment
Energy Technology Data Exchange (ETDEWEB)
Carlton, W.H.; Denham, M.
1996-07-01
This document assesses the impact of radioactive activation products released from SRS facilities since the first reactor became operational late in 1953. The isotopes reported here are those whose release resulted in the highest dose to people living near SRS: {sup 32}P, {sup 51}Cr, {sup 60}C, and {sup 65}Zn. Release pathways, emission control features, and annual releases to the aqueous and atmospheric environments are discussed. No single incident has resulted in a major acute release of activation products to the environment. The releases were the result of normal operations of the reactors and separations facilities. Releases declined over the years as better controls were established and production was reduced. The overall radiological impact of SRS activation product atmospheric releases from 1954 through 1994 on the offsite maximally exposed individual can be characterized by a total dose of 0.76 mrem. During the same period, such an individual received a total dose of 14,400 mrem from non-SRS sources of ionizing radiation present in the environment. SRS activation product aqueous releases between 1954 and 1994 resulted in a total dose of 54 mrem to the offsite maximally exposed individual. The impact of SRS activation product releases on offsite populations also has been evaluated.
2. Characterization of an Active Thermal Erosion Site, Caribou Creek, Alaska
Science.gov (United States)
Busey, R.; Bolton, W. R.; Cherry, J. E.; Hinzman, L. D.
2013-12-01
The goal of this project is to estimate volume loss of soil over time from this site, provide parameterizations on erodibility of ice rich permafrost and serve as a baseline for future landscape evolution simulations. Located in the zone of discontinuous permafrost, the interior region of Alaska (USA) is home to a large quantity of warm, unstable permafrost that is both high in ice content and has soil temperatures near the freezing point. Much of this permafrost maintains a frozen state despite the general warming air temperature trend in the region due to the presence of a thick insulating organic mat and a dense root network in the upper sub-surface of the soil column. At a rapidly evolving thermo-erosion site, located within the Caribou-Poker Creeks Research Watershed (part of the Bonanza Creek LTER) near Chatanika, Alaska (N65.140, W147.570), the protective organic layer and associated plants were disturbed by an adjacent traditional use trail and the shifting of a groundwater spring. These triggers have led to rapid geomorphological change on the landscape as the soil thaws and sediment is transported into the creek at the valley bottom. Since 2006 (approximately the time of initiation), the thermal erosion has grown to 170 meters length, 3 meters max depth, and 15 meters maximum width. This research combines several data sets: DGPS survey, imagery from an extremely low altitude pole-based remote sensing (3 to 5 meters above ground level), and imagery from an Unmanned Aerial System (UAS) at about 60m altitude.
3. Site directed mutagenesis of amino acid residues at the active site of mouse aldehyde oxidase AOX1.
Directory of Open Access Journals (Sweden)
Silvia Schumann
Full Text Available Mouse aldehyde oxidase (mAOX1 forms a homodimer and belongs to the xanthine oxidase family of molybdoenzymes which are characterized by an essential equatorial sulfur ligand coordinated to the molybdenum atom. In general, mammalian AOs are characterized by broad substrate specificity and an yet obscure physiological function. To define the physiological substrates and the enzymatic characteristics of mAOX1, we established a system for the heterologous expression of the enzyme in Escherichia coli. The recombinant protein showed spectral features and a range of substrate specificity similar to the native protein purified from mouse liver. The EPR data of recombinant mAOX1 were similar to those of AO from rabbit liver, but differed from the homologous xanthine oxidoreductase enzymes. Site-directed mutagenesis of amino acids Val806, Met884 and Glu1265 at the active site resulted in a drastic decrease in the oxidation of aldehydes with no increase in the oxidation of purine substrates. The double mutant V806E/M884R and the single mutant E1265Q were catalytically inactive enzymes regardless of the aldehyde or purine substrates tested. Our results show that only Glu1265 is essential for the catalytic activity by initiating the base-catalyzed mechanism of substrate oxidation. In addition, it is concluded that the substrate specificity of molybdo-flavoenzymes is more complex and not only defined by the three characterized amino acids in the active site.
4. Active site densities, oxygen activation and adsorbed reactive oxygen in alcohol activation on npAu catalysts
Energy Technology Data Exchange (ETDEWEB)
Wang, Lu-Cun [Department of Chemistry and Chemical Biology; Harvard University; Cambridge, USA; Friend, C. M. [Department of Chemistry and Chemical Biology; Harvard University; Cambridge, USA; School of Engineering and Applied Sciences; Harvard University; Fushimi, Rebecca [Parks College of Engineering, Aviation and Technology; Saint Louis University; Saint Louis, USA; The Langmuir Research Institute; Saint Louis; Madix, Robert J. [School of Engineering and Applied Sciences; Harvard University; Cambridge, USA
2016-01-01
The activation of molecular O2as well as the reactivity of adsorbed oxygen species is of central importance in aerobic selective oxidation chemistry on Au-based catalysts. Herein, we address the issue of O2activation on unsupported nanoporous gold (npAu) catalysts by applying a transient pressure technique, a temporal analysis of products (TAP) reactor, to measure the saturation coverage of atomic oxygen, its collisional dissociation probability, the activation barrier for O2dissociation, and the facility with which adsorbed O species activate methanol, the initial step in the catalytic cycle of esterification. The results from these experiments indicate that molecular O2dissociation is associated with surface silver, that the density of reactive sites is quite low, that adsorbed oxygen atoms do not spill over from the sites of activation onto the surrounding surface, and that methanol reacts quite facilely with the adsorbed oxygen atoms. In addition, the O species from O2dissociation exhibits reactivity for the selective oxidation of methanol but not for CO. The TAP experiments also revealed that the surface of the npAu catalyst is saturated with adsorbed O under steady state reaction conditions, at least for the pulse reaction.
5. Application of gas phase cryogenic vibrational spectroscopy to characterize the CO2, CO, N2 and N2O interactions with the open coordination site on a Ni(I) macrocycle using dual cryogenic ion traps
Science.gov (United States)
Craig, Stephanie M.; Menges, Fabian S.; Johnson, Mark A.
2017-02-01
Recent advances in gas phase ion chemistry, coupled with cryogenic ion vibrational predissociation spectroscopy, provide a powerful way to characterize the structures of small molecules bound to open coordination sites of organometallic compounds. Here we extend our previous measurements on the relatively weakly interacting CO2 molecule with a Ni(I) tetraaza-macrocyclic compound to enable the characterization of more strongly interacting substrates. We first confirm the calculated η2-C,O binding motif of CO2 using isotopic labeling by direct, one photon vibrational predissociation of the Ni(I)-CO2 complex. We then apply this approach to study complexation of N2 at the active site. The generality of the method is then expanded to include application to more strongly bound systems that cannot be photodissociated with one IR photon. This involves implementation of a recently developed scheme (Marsh et al., 2015) involving two temperature-controlled ion traps. The first is optimized to complex the substrate molecule to the active site and the second is cooled to around 10 K to enable condensation of weakly bound "tag" molecules onto the target complex so as to enable its characterization by linear vibrational predissociation spectroscopy. We demonstrate this capability by applying it to the coordination of CO to the active Ni(I) site, as well as to elucidate the nature of the products that are formed upon reaction with N2O.
6. Developing restoration planting mixes for active ski slopes: a multi-site reference community approach.
Science.gov (United States)
Burt, Jennifer Williamson
2012-03-01
Downhill ski areas occupy large expanses of mountainous lands where restoration of ecosystem function is of increasing importance and interest. Establishing diverse native plant communities on ski runs should enhance sediment and water retention, wildlife habitat, biodiversity and aesthetics. Because ski slopes are managed for recreation, ski slope revegetation mixes must consist of low-stature or herbaceous plants that can tolerate typical environmental conditions on ski slopes (high elevation, disturbed soils, open, steep slopes). The most appropriate reference communities for selecting ski slope revegetation species are thus successional, or seral plant communities in similar environments (i.e., other ski slopes). Using results from a broad-scale reference community analysis, I evaluated plant communities naturally occurring on ski slopes from 21 active and abandoned ski areas throughout the northern Sierra Nevada to identify native plant species suitable for use in ski slope restoration. I constructed a baseline planting palette of regionally appropriate plant species (for restoration of either newly created or already existing ski runs) that is functionally diverse and is likely to succeed across a broad range of environments. I also identify a more comprehensive list of species for more specialized planting mixes based on site-specific goals and particular environmental settings. Establishing seral plant communities may be an appropriate restoration goal for many other types of managed lands, including roadsides, firebreaks and utility rights-of-way. This study describes an ecological (and potentially cost-effective) approach to developing restoration planting palettes for such managed lands.
7. The landscape degradation in the mining sites with suspended activity
Directory of Open Access Journals (Sweden)
Anca IONCE
2009-08-01
Full Text Available The extracting industry, through its extraction activities, of shipping the ores, of breaking the ores, of preparing the practical substances, of stowing the useless rock, of transporting the practical substances, etc. might modify the area’s relief and the quality of ground, of thesurface waters and of the air. Suceava County has an old tradition of mining, where the results of this activity are visible, especially the visual point of view, and where not taking certain measures of ecological remediation will emphasize the disappointing image of the landscape within the areas of mining activity performing.The predominant mountainous landscape, in which mining activities have been held, is being affected also by the abandoned industrial and administrative buildings, in an advanced degradation state.The hydrographic system, very rich in mining areas, has its water quality affected by the acid rock drainage- phenomenon which appeared in many mining waste deposits.
8. Location and activity specific site-management for military locations
NARCIS (Netherlands)
Maring, L.; Hulst, M. van; Meuken, D.
2009-01-01
pace is limited in the Netherlands and military activities, that may cause nuisance or environmental hazards, should therefore be considered and evaluated during the use of military locations. The last few years TNO and Deltares have worked on a research program on environmental effects due to milit
9. Encroachment of Human Activity on Sea Turtle Nesting Sites
Science.gov (United States)
Ziskin, D.; Aubrecht, C.; Elvidge, C.; Tuttle, B.; Baugh, K.; Ghosh, T.
2008-12-01
The encroachment of anthropogenic lighting on sea turtle nesting sites poses a serious threat to the survival of these animals [Nicholas, 2001]. This danger is quantified by combining two established data sets. The first is the Nighttime Lights data produced by the NOAA National Geophysical Data Center [Elvidge et al., 1997]. The second is the Marine Turtle Database produced by the World Conservation Monitoring Centre (WCMC). The technique used to quantify the threat of encroachment is an adaptation of the method described in Aubrecht et al. [2008], which analyzes the stress on coral reef systems by proximity to nighttime lights near the shore. Nighttime lights near beaches have both a direct impact on turtle reproductive success since they disorient hatchlings when they mistake land-based lights for the sky-lit surf [Lorne and Salmon, 2007] and the lights are also a proxy for other anthropogenic threats. The identification of turtle nesting sites with high rates of encroachment will hopefully steer conservation efforts to mitigate their effects [Witherington, 1999]. Aubrecht, C, CD Elvidge, T Longcore, C Rich, J Safran, A Strong, M Eakin, KE Baugh, BT Tuttle, AT Howard, EH Erwin, 2008, A global inventory of coral reef stressors based on satellite observed nighttime lights, Geocarto International, London, England: Taylor and Francis. In press. Elvidge, CD, KE Baugh, EA Kihn, HW Kroehl, ER Davis, 1997, Mapping City Lights with Nighttime Data from the DMSP Operational Linescan System, Photogrammatic Engineering and Remote Sensing, 63:6, pp. 727-734. Lorne, JK, M Salmon, 2007, Effects of exposure to artificial lighting on orientation of hatchling sea turtles on the beach and in the ocean, Endangered Species Research, Vol. 3: 23-30. Nicholas, M, 2001, Light Pollution and Marine Turtle Hatchlings: The Straw that Breaks the Camel's Back?, George Wright Forum, 18:4, p77-82. Witherington, BE, 1999, Reducing Threats To Nesting Habitat, Research and Management Techniques for
10. Chemical Concentrations in Field Mice from Open-Detonation Firing Sites TA-36 Minie and TA-39 Point 6 at Los Alamos National Laboratory
Energy Technology Data Exchange (ETDEWEB)
Fresquez, Philip R. [Los Alamos National Laboratory
2011-01-01
Field mice (mostly Peromyscus spp.) were collected at two open-detonation (high explosive) firing sites - Minie at Technical Area (TA) 36 and Point 6 at TA-39 - at Los Alamos National Laboratory in August of 2010 and in February of 2011 for chemical analysis. Samples of whole body field mice from both sites were analyzed for target analyte list elements (mostly metals), dioxin/furans, polychlorinated biphenyl congeners, high explosives, and perchlorate. In addition, uranium isotopes were analyzed in a composite sample collected from TA-36 Minie. In general, all constituents, with the exception of lead at TA-39 Point 6, in whole body field mice samples collected from these two open-detonation firing sites were either not detected or they were detected below regional statistical reference levels (99% confidence level), biota dose screening levels, and/or soil ecological chemical screening levels. The amount of lead in field mice tissue collected from TA-39 Point 6 was higher than regional background, and some lead levels in the soil were higher than the ecological screening level for the field mouse; however, these levels are not expected to affect the viability of the populations over the site as a whole.
11. Diffusion dynamics in external noise-activated non-equilibrium open system-reservoir coupling environment
Institute of Scientific and Technical Information of China (English)
Wang Chun-Yang
2013-01-01
The diffusion process in an extemal noise-activated non-equilibrium open system-reservoir coupling environment is studied by analytically solving the generalized Langevin equation.The dynamical property of the system near the barrier top is investigated in detail by numerically calculating the quantities such as mean diffusion path,invariance,barrier passing probability,and so on.It is found that,comparing with the unfavorable effect of internal fluctuations,the external noise activation is sometimes beneficial to the diffusion process.An optimal strength of external activation or correlation time of the internal fluctuation is expected for the diffusing particle to have a maximal probability to escape from the potential well.
12. Characterization and restoration of performance of {open_quotes}aged{close_quotes} radioiodine removing activated carbons
Energy Technology Data Exchange (ETDEWEB)
Freeman, W.P. [NUCON International, Inc., Columbus, OH (United States)
1997-08-01
The degradation of radioiodine removal performance for impregnated activated carbons because of ageing is well established. However, the causes for this degradation remain unclear. One theory is that this reduction in performance from the ageing process results from an oxidation of the surface of the carbon. Radioiodine removing activated carbons that failed radioiodine removal tests showed an oxidized surface that had become hydrophilic compared with new carbons. We attempted to restore the performance of these {open_quotes}failed{close_quotes} carbons with a combination of thermal and chemical treatment. The results of these investigations are presented and discussed with the view of extending the life of radioiodine removing activated carbons. 4 refs., 2 tabs.
13. Variable temperature effects of Open Top Chambers at polar and alpine sites explained by irradiance and snow depth
NARCIS (Netherlands)
Bokhorst, S.; Huiskes, A.; Aerts, R.; Convey, P.; Cooper, E.J.; Dalen, L.; Erschbamer, B.; Gudmundsson, J.; Hofgaard, H.; Hollister, R.D.; Johnstone, J.; Jónsdóttir, I.S.; Lebouvier, M.; Van de Vijver, B.; Wahren, C.-H.; Dorrepaal, E.
2013-01-01
Environmental manipulation studies are integral to determining biological consequences of climate warming. Open Top Chambers (OTCs) have been widely used to assess summer warming effects on terrestrial biota, with their effects during other seasons normally being given less attention even though cha
14. Eyelid Opening with Trigeminal Proprioceptive Activation Regulates a Brainstem Arousal Mechanism.
Science.gov (United States)
Matsuo, Kiyoshi; Ban, Ryokuya; Hama, Yuki; Yuzuriha, Shunsuke
2015-01-01
Eyelid opening stretches mechanoreceptors in the supratarsal Müller muscle to activate the proprioceptive fiber supplied by the trigeminal mesencephalic nucleus. This proprioception induces reflex contractions of the slow-twitch fibers in the levator palpebrae superioris and frontalis muscles to sustain eyelid and eyebrow positions against gravity. The cell bodies of the trigeminal proprioceptive neurons in the mesencephalon potentially make gap-junctional connections with the locus coeruleus neurons. The locus coeruleus is implicated in arousal and autonomic function. Due to the relationship between arousal, ventromedial prefrontal cortex, and skin conductance, we assessed whether upgaze with trigeminal proprioceptive evocation activates sympathetically innervated sweat glands and the ventromedial prefrontal cortex. Specifically, we examined whether 60° upgaze induces palmar sweating and hemodynamic changes in the prefrontal cortex in 16 subjects. Sweating was monitored using a thumb-mounted perspiration meter, and prefrontal cortex activity was measured with 45-channel, functional near-infrared spectroscopy (fNIRS) and 2-channel NIRS at Fp1 and Fp2. In 16 subjects, palmar sweating was induced by upgaze and decreased in response to downgaze. Upgaze activated the ventromedial prefrontal cortex with an accumulation of integrated concentration changes in deoxyhemoglobin, oxyhemoglobin, and total hemoglobin levels in 12 subjects. Upgaze phasically and degree-dependently increased deoxyhemoglobin level at Fp1 and Fp2, whereas downgaze phasically decreased it in 16 subjects. Unilateral anesthetization of mechanoreceptors in the supratarsal Müller muscle used to significantly reduce trigeminal proprioceptive evocation ipsilaterally impaired the increased deoxyhemoglobin level by 60° upgaze at Fp1 or Fp2 in 6 subjects. We concluded that upgaze with strong trigeminal proprioceptive evocation was sufficient to phasically activate sympathetically innervated sweat glands
15. Eyelid Opening with Trigeminal Proprioceptive Activation Regulates a Brainstem Arousal Mechanism.
Directory of Open Access Journals (Sweden)
Kiyoshi Matsuo
Full Text Available Eyelid opening stretches mechanoreceptors in the supratarsal Müller muscle to activate the proprioceptive fiber supplied by the trigeminal mesencephalic nucleus. This proprioception induces reflex contractions of the slow-twitch fibers in the levator palpebrae superioris and frontalis muscles to sustain eyelid and eyebrow positions against gravity. The cell bodies of the trigeminal proprioceptive neurons in the mesencephalon potentially make gap-junctional connections with the locus coeruleus neurons. The locus coeruleus is implicated in arousal and autonomic function. Due to the relationship between arousal, ventromedial prefrontal cortex, and skin conductance, we assessed whether upgaze with trigeminal proprioceptive evocation activates sympathetically innervated sweat glands and the ventromedial prefrontal cortex. Specifically, we examined whether 60° upgaze induces palmar sweating and hemodynamic changes in the prefrontal cortex in 16 subjects. Sweating was monitored using a thumb-mounted perspiration meter, and prefrontal cortex activity was measured with 45-channel, functional near-infrared spectroscopy (fNIRS and 2-channel NIRS at Fp1 and Fp2. In 16 subjects, palmar sweating was induced by upgaze and decreased in response to downgaze. Upgaze activated the ventromedial prefrontal cortex with an accumulation of integrated concentration changes in deoxyhemoglobin, oxyhemoglobin, and total hemoglobin levels in 12 subjects. Upgaze phasically and degree-dependently increased deoxyhemoglobin level at Fp1 and Fp2, whereas downgaze phasically decreased it in 16 subjects. Unilateral anesthetization of mechanoreceptors in the supratarsal Müller muscle used to significantly reduce trigeminal proprioceptive evocation ipsilaterally impaired the increased deoxyhemoglobin level by 60° upgaze at Fp1 or Fp2 in 6 subjects. We concluded that upgaze with strong trigeminal proprioceptive evocation was sufficient to phasically activate sympathetically
16. Lipolytic activity from bacteria prospected in polluted portuary sites
Directory of Open Access Journals (Sweden)
Kaori Levy Fonseca
2014-06-01
This study demonstrates that these TBT resistant isolates have, at the same time, the capacity to produce enzymes with a large biotechnological potential but, nevertheless, their relationship is not well understood, representing a novel approach. It is expected for these organisms to produce highly biotechnological relevant biocatalysts, due to their severe adaptations (Suehiro et al., 2007. The fully characterization of these lipases, mostly for F3 with elevated lipolytic activity exhibited, presents also a future challenge.
17. Opening the conformation is a master switch for the dual localization and phosphatase activity of PTEN
Science.gov (United States)
Nguyen, Hoai-Nghia; Yang, Jr-Ming; Miyamoto, Takafumi; Itoh, Kie; Rho, Elmer; Zhang, Qiang; Inoue, Takanari; Devreotes, Peter N.; Sesaki, Hiromi; Iijima, Miho
2015-01-01
Tumor suppressor PTEN mainly functions at two subcellular locations, the plasma membrane and the nucleus. At the plasma membrane, PTEN dephosphorylates the tumorigenic second messenger PIP3, which drives cell proliferation and migration. In the nucleus, PTEN controls DNA repair and genome stability independently of PIP3. Whereas the concept that a conformational change regulates protein function through post-translational modifications has been well established in biology, it is unknown whether a conformational change simultaneously controls dual subcellular localizations of proteins. Here, we discovered that opening the conformation of PTEN is the crucial upstream event that determines its key dual localizations of this crucial tumor suppressor. We identify a critical conformational switch that regulates PTEN’s localization. Most PTEN molecules are held in the cytosol in a closed conformation by intramolecular interactions between the C-terminal tail and core region. Dephosphorylation of the tail opens the conformation and exposes the membrane-binding regulatory interface in the core region, recruiting PTEN to the membrane. Moreover, a lysine at residue 13 is also exposed and when ubiquitinated, transports PTEN to the nucleus. Thus, opening the conformation of PTEN is a key mechanism that enhances its dual localization and enzymatic activity, providing a potential therapeutic strategy in cancer treatments. PMID:26216063
18. Molecular Basis for Enzymatic Sulfite Oxidation -- HOW THREE CONSERVED ACTIVE SITE RESIDUES SHAPE ENZYME ACTIVITY
Energy Technology Data Exchange (ETDEWEB)
Bailey, Susan; Rapson, Trevor; Johnson-Winters, Kayunta; Astashkin, Andrei; Enemark, John; Kappler, Ulrike
2008-11-10
Sulfite dehydrogenases (SDHs) catalyze the oxidation and detoxification of sulfite to sulfate, a reaction critical to all forms of life. Sulfite-oxidizing enzymes contain three conserved active site amino acids (Arg-55, His-57, and Tyr-236) that are crucial for catalytic competency. Here we have studied the kinetic and structural effects of two novel and one previously reported substitution (R55M, H57A, Y236F) in these residues on SDH catalysis. Both Arg-55 and His-57 were found to have key roles in substrate binding. An R55M substitution increased Km(sulfite)(app) by 2-3 orders of magnitude, whereas His-57 was required for maintaining a high substrate affinity at low pH when the imidazole ring is fully protonated. This effect may be mediated by interactions of His-57 with Arg-55 that stabilize the position of the Arg-55 side chain or, alternatively, may reflect changes in the protonation state of sulfite. Unlike what is seen for SDHWT and SDHY236F, the catalytic turnover rates of SDHR55M and SDHH57A are relatively insensitive to pH (~;;60 and 200 s-1, respectively). On the structural level, striking kinetic effects appeared to correlate with disorder (in SDHH57A and SDHY236F) or absence of Arg-55 (SDHR55M), suggesting that Arg-55 and the hydrogen bonding interactions it engages in are crucial for substrate binding and catalysis. The structure of SDHR55M has sulfate bound at the active site, a fact that coincides with a significant increase in the inhibitory effect of sulfate in SDHR55M. Thus, Arg-55 also appears to be involved in enabling discrimination between the substrate and product in SDH.
19. Identification of inhibitors against the potential ligandable sites in the active cholera toxin.
Science.gov (United States)
2015-04-01
The active cholera toxin responsible for the massive loss of water and ions in cholera patients via its ADP ribosylation activity is a heterodimer of the A1 subunit of the bacterial holotoxin and the human cytosolic ARF6 (ADP Ribosylation Factor 6). The active toxin is a potential target for the design of inhibitors against cholera. In this study we identified the potential ligandable sites of the active cholera toxin which can serve as binding sites for drug-like molecules. By employing an energy-based approach to identify ligand binding sites, and comparison with the results of computational solvent mapping, we identified two potential ligandable sites in the active toxin which can be targeted during structure-based drug design against cholera. Based on the probe affinities of the identified ligandable regions, docking-based virtual screening was employed to identify probable inhibitors against these sites. Several indole-based alkaloids and phosphates showed strong interactions to the important residues of the ligandable region at the A1 active site. On the other hand, 26 top scoring hits were identified against the ligandable region at the A1 ARF6 interface which showed strong hydrogen bonding interactions, including guanidines, phosphates, Leucopterin and Aristolochic acid VIa. This study has important implications in the application of hybrid structure-based and ligand-based methods against the identified ligandable sites using the identified inhibitors as reference ligands, for drug design against the active cholera toxin.
20. Cooperative activation of cardiac transcription through myocardin bridging of paired MEF2 sites
Energy Technology Data Exchange (ETDEWEB)
Anderson, Courtney M. [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Hu, Jianxin [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Thomas, Reuben [Univ. of California, San Francisco, CA (United States). Gladstone Inst.; Gainous, T. Blair [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Celona, Barbara [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Sinha, Tanvi [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Dickel, Diane E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Genomics Division; Heidt, Analeah B. [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Xu, Shan-Mei [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Bruneau, Benoit G. [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Univ. of California, San Francisco, CA (United States). Gladstone Inst.; Pollard, Katherine S. [Univ. of California, San Francisco, CA (United States). Gladstone Inst.; Pennacchio, Len A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Genomics Division; Black, Brian L. [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Univ. of California, San Francisco, CA (United States). Dept. of
2017-03-28
Enhancers frequently contain multiple binding sites for the same transcription factor. These homotypic binding sites often exhibit synergy, whereby the transcriptional output from two or more binding sites is greater than the sum of the contributions of the individual binding sites alone. Although this phenomenon is frequently observed, the mechanistic basis for homotypic binding site synergy is poorly understood. Here in this paper, we identify a bona fide cardiac-specific Prkaa2 enhancer that is synergistically activated by homotypic MEF2 binding sites. We show that two MEF2 sites in the enhancer function cooperatively due to bridging of the MEF2C-bound sites by the SAP domain-containing co-activator protein myocardin, and we show that paired sites buffer the enhancer from integration site-dependent effects on transcription in vivo. Paired MEF2 sites are prevalent in cardiac enhancers, suggesting that this might be a common mechanism underlying synergy in the control of cardiac gene expression in vivo.
1. Active Site Metal Occupancy and Cyclic Di-GMP Phosphodiesterase Activity of Thermotoga maritima HD-GYP.
Science.gov (United States)
Miner, Kyle D; Kurtz, Donald M
2016-02-16
HD-GYPs make up a subclass of the metal-dependent HD phosphohydrolase superfamily and catalyze conversion of cyclic di(3',5')-guanosine monophosphate (c-di-GMP) to 5'-phosphoguanylyl-(3'→5')-guanosine (pGpG) and GMP. Until now, the only reported crystal structure of an HD-GYP that also exhibits c-di-GMP phosphodiesterase activity contains a His/carboxylate ligated triiron active site. However, other structural and phylogenetic correlations indicate that some HD-GYPs contain dimetal active sites. Here we provide evidence that an HD-GYP c-di-GMP phosphodiesterase, TM0186, from Thermotoga maritima can accommodate both di- and trimetal active sites. We show that an as-isolated iron-containing TM0186 has an oxo/carboxylato-bridged diferric site, and that the reduced (diferrous) form is necessary and sufficient to catalyze conversion of c-di-GMP to pGpG, but that conversion of pGpG to GMP requires more than two metals per active site. Similar c-di-GMP phosphodiesterase activities were obtained with divalent iron or manganese. On the basis of activity correlations with several putative metal ligand residue variants and molecular dynamics simulations, we propose that TM0186 can accommodate both di- and trimetal active sites. Our results also suggest that a Glu residue conserved in a subset of HD-GYPs is required for formation of the trimetal site and can also serve as a labile ligand to the dimetal site. Given the anaerobic growth requirement of T. maritima, we suggest that this HD-GYP can function in vivo with either divalent iron or manganese occupying di- and trimetal sites.
2. The Case of Open Leisure Activities Organized in Swedish Local Councils: The Role of Citizenship and Entrepreneurship Skills Development
Science.gov (United States)
Lindström, Lisbeth
2016-01-01
In this article, we contribute to theory by integrating literature on citizenship and entrepreneurship, based on which we develop a framework for how personal development is achieved for young people in the context of open leisure activities. The empirical material in this study consists of survey data collected in Swedish open leisure centers. A…
3. Sequencing of the amylopullulanase (apu) gene of Thermoanaerobacter ethanolicus 39E, and identification of the active site by site-directed mutagenesis.
Science.gov (United States)
Mathupala, S P; Lowe, S E; Podkovyrov, S M; Zeikus, J G
1993-08-01
The complete nucleotide sequence of the gene encoding the dual active amylopullulanase of Thermoanaerobacter ethanolicus 39E (formerly Clostridium thermohydrosulfuricum) was determined. The structural gene (apu) contained a single open reading frame 4443 base pairs in length, corresponding to 1481 amino acids, with an estimated molecular weight of 162,780. Analysis of the deduced sequence of apu with sequences of alpha-amylases and alpha-1,6 debranching enzymes enabled the identification of four conserved regions putatively involved in substrate binding and in catalysis. The conserved regions were localized within a 2.9-kilobase pair gene fragment, which encoded a M(r) 100,000 protein that maintained the dual activities and thermostability of the native enzyme. The catalytic residues of amylopullulanase were tentatively identified by using hydrophobic cluster analysis for comparison of amino acid sequences of amylopullulanase and other amylolytic enzymes. Asp597, Glu626, and Asp703 were individually modified to their respective amide form, or the alternate acid form, and in all cases both alpha-amylase and pullulanase activities were lost, suggesting the possible involvement of 3 residues in a catalytic triad, and the presence of a putative single catalytic site within the enzyme. These findings substantiate amylopullulanase as a new type of amylosaccharidase.
4. Active site proton delivery and the lyase activity of human CYP17A1
Energy Technology Data Exchange (ETDEWEB)
Khatri, Yogan; Gregory, Michael C.; Grinkova, Yelena V.; Denisov, Ilia G.; Sligar, Stephen G., E-mail: [email protected]
2014-01-03
equivalents and protons are funneled into non-productive pathways. This is similar to previous work with other P450 catalyzed hydroxylation. However, catalysis of carbon–carbon bond scission by the T306A mutant was largely unimpeded by disruption of the CYP17A1 acid-alcohol pair. The unique response of CYP17A1 lyase activity to mutation of Thr306 is consistent with a reactive intermediate formed independently of proton delivery in the active site, and supports involvement of a nucleophilic peroxo-anion rather than the traditional Compound I in catalysis.
5. Changes in activities performed in leisure time after open heart surgery.
Science.gov (United States)
Bunzel, B; Eckersberger, F
1989-06-01
To assess any changes made in the leisure activities performed after open heart surgery, 94 patients (48 with aortocoronary bypass operation, 46 with valve replacements) were asked exactly one year postoperatively whether activities, collected in a list of 21 items, had increased, decreased or remained equal since their operation. In spite of the fact that most leisure activities seemed to have remained unchanged, after operation patients seem to undertake activities quite contrary to their motivations for undergoing surgery in the first place: active participation (such as involvement in some kind of sport, going out to cinema, theatre, restaurants,...) decreases, whereas passive activities (such as watching sports on television, listening to music,...) increases significantly. Although 90% of the patients stated their physical, and 67% their emotional status, as being clearly improved compared to preoperative values, the experience of body limitations as well as of fear and anxiety seems to be so durable that the patients, now in good condition, become passive onlookers and cease to participate in social life.
6. Did Open Solar Magnetic Field Increase during the Last 100 Years: A Reanalysis of Geomagnetic Activity
CERN Document Server
Mursula, K; Karinen, A
2004-01-01
Long-term geomagnetic activity presented by the aa index has been used to show that the heliospheric magnetic field has more than doubled during the last 100 years. However, serious concern has been raised on the long-term consistency of the aa index and on the centennial rise of the solar magnetic field. Here we reanalyze geomagnetic activity during the last 100 years by calculating the recently suggested IHV (Inter-Hour Variability) index as a measure of local geomagnetic activity for seven stations. We find that local geomagnetic activity at all stations follows the same qualitative long-term pattern: an increase from early 1900s to 1960, a dramatic dropout in 1960s and a (mostly weaker) increase thereafter. Moreover, at all stations, the activity at the end of the 20th century has a higher average level than at the beginning of the century. This agrees with the result based on the aa index that global geomagnetic activity, and thereby, the open solar magnetic field has indeed increased during the last 100...
7. Alaska Open-file Report 144 Assessment of Thermal Springs Sites Aleutian Arc, Atka Island to Becherof Lake -- Preliminary Results and Evaluation
Energy Technology Data Exchange (ETDEWEB)
Motyka, R.J.; Moorman, M.A.; Liss, S.A.
1981-12-01
Twenty of more than 30 thermal spring areas reported to exist in the Aleutian arc extending from Atka Island to Becherof Lake were investigated during July and August, 1980. Thermal activity of three of these sites had diminished substantially or no longer existed. At least seven more sites where thermal-spring activity is probable or certain were not visited because of their remoteness or because of time constraints. The existence of several other reported thermal spring sites could not be verified; these sites are considered questionable. On the basis of geothermometry, subsurface reservoir temperatures in excess of 150 C are estimated for 10 of the thermal spring sites investigated. These sites all occur in or near regions of Recent volcanism. Five of the sites are characterized by fumaroles and steaming ground, indicating the presence of at least a shallow vapor-dominated zone. Two, the Makushin Valley and Glacier Valley thermal areas, occur on the flanks of active Mukushin Volcano located on Unalaska Island, and may be connected to a common source of heat. Gas geothermometry suggests that the reservoir feeding the Kliuchef thermal field, located on the flanks of Kliuchef volcano of northeast Atka Island, may be as high as 239 C.
8. Low Cost Open-Path Instrument for Monitoring Surface Carbon Dioxide at Sequestration Sites Phase I SBIR Final Report
Energy Technology Data Exchange (ETDEWEB)
Wu, Sheng
2012-10-02
Public confidence in safety is a prerequisite to the success of carbon dioxide (CO2) capture and storage for any program that intends to mitigate greenhouse gas emissions. In that regard, this project addresses the security of CO2 containment by undertaking development of what is called an open path device to measure CO2 concentrations near the ground above a CO2 storage area.
9. Using Carbohydrate Interaction Assays to Reveal Novel Binding Sites in Carbohydrate Active Enzymes
DEFF Research Database (Denmark)
Cockburn, Darrell; Wilkens, Casper; Dilokpimol, Adiphol
2016-01-01
Carbohydrate active enzymes often contain auxiliary binding sites located either on independent domains termed carbohydrate binding modules (CBMs) or as so-called surface binding sites (SBSs) on the catalytic module at a certain distance from the active site. The SBSs are usually critical...... for the activity of their cognate enzyme, though they are not readily detected in the sequence of a protein, but normally require a crystal structure of a complex for their identification. A variety of methods, including affinity electrophoresis (AE), insoluble polysaccharide pulldown (IPP) and surface plasmon...... sites, but also for identifying new ones, even without structural data available. We further verify the chosen assays discriminate between known SBS/CBM containing enzymes and negative controls. Altogether 35 enzymes are screened for the presence of SBSs or CBMs and several novel binding sites...
10. Active open boundary forcing using dual relaxation time-scales in downscaled ocean models
Science.gov (United States)
Herzfeld, M.; Gillibrand, P. A.
2015-05-01
Regional models actively forced with data from larger scale models at their open boundaries often contain motion at different time-scales (e.g. tidal and low frequency). These motions are not always individually well specified in the forcing data, and one may require a more active boundary forcing while the other exert less influence on the model interior. If a single relaxation time-scale is used to relax toward these data in the boundary equation, then this may be difficult. The method of fractional steps is used to introduce dual relaxation time-scales in an open boundary local flux adjustment scheme. This allows tidal and low frequency oscillations to be relaxed independently, resulting in a better overall solution than if a single relaxation parameter is optimized for tidal (short relaxation) or low frequency (long relaxation) boundary forcing. The dual method is compared to the single relaxation method for an idealized test case where a tidal signal is superimposed on a steady state low frequency solution, and a real application where the low frequency boundary forcing component is derived from a global circulation model for a region extending over the whole Great Barrier Reef, and a tidal signal subsequently superimposed.
11. Structure and nuclearity of active sites in Fe-zeolites: comparison with iron sites in enzymes and homogeneous catalysts.
Science.gov (United States)
Zecchina, Adriano; Rivallan, Mickaël; Berlier, Gloria; Lamberti, Carlo; Ricchiardi, Gabriele
2007-07-21
Fe-ZSM-5 and Fe-silicalite zeolites efficiently catalyse several oxidation reactions which find close analogues in the oxidation reactions catalyzed by homogeneous and enzymatic compounds. The iron centres are highly dispersed in the crystalline matrix and on highly diluted samples, mononuclear and dinuclear structures are expected to become predominant. The crystalline and robust character of the MFI framework has allowed to hypothesize that the catalytic sites are located in well defined crystallographic positions. For this reason these catalysts have been considered as the closest and best defined heterogeneous counterparts of heme and non heme iron complexes and of Fenton type Fe(2+) homogeneous counterparts. On this basis, an analogy with the methane monooxygenase has been advanced several times. In this review we have examined the abundant literature on the subject and summarized the most widely accepted views on the structure, nuclearity and catalytic activity of the iron species. By comparing the results obtained with the various characterization techniques, we conclude that Fe-ZSM-5 and Fe-silicalite are not the ideal samples conceived before and that many types of species are present, some active and some other silent from adsorptive and catalytic point of view. The relative concentration of these species changes with thermal treatments, preparation procedures and loading. Only at lowest loadings the catalytically active species become the dominant fraction of the iron species. On the basis of the spectroscopic titration of the active sites by using NO as a probe, we conclude that the active species on very diluted samples are isolated and highly coordinatively unsaturated Fe(2+) grafted to the crystalline matrix. Indication of the constant presence of a smaller fraction of Fe(2+) presumably located on small clusters is also obtained. The nitrosyl species formed upon dosing NO from the gas phase on activated Fe-ZSM-5 and Fe-silicalite, have been analyzed
12. 77 FR 3460 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites
Science.gov (United States)
2012-01-24
... Uranium and Thorium Processing Sites AGENCY: Department of Energy. ACTION: Notice of the acceptance of... (DOE) acceptance of claims in FY 2012 from eligible active uranium and thorium processing site... uranium and thorium licensees for certain costs of decontamination, decommissioning, reclamation,...
13. 75 FR 71677 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites
Science.gov (United States)
2010-11-24
... Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites AGENCY: Department of... uranium and thorium processing site licensees for reimbursement under Title X of the Energy Policy Act of... requires DOE to reimburse eligible uranium and thorium licensees for certain costs of...
14. The balance of flexibility and rigidity in the active site residues of hen egg white lysozyme
Institute of Scientific and Technical Information of China (English)
Qi Jian-Xun; Jiang Fan
2011-01-01
The crystallographic temperature factors (B factor) of individual atoms contain important information about the thermal motion of the atoms in a macromolecule. Previously the theory of flexibility of active site has been established based on the observation that the enzyme activity is sensitive to low concentration denaturing agents. It has been found that the loss of enzyme activity occurs well before the disruption of the three-dimensional structural scaffold of the enzyme. To test the theory of conformational flexibility of enzyme active site, crystal structures were perturbed by soaking in low concentration guanidine hydrochloride solutions. It was found that many lysozyme crystals tested could still diffract until the concentration of guanidine hydrochloride reached 3 M. It was also found that the B factors averaged over individually collected data sets were more accurate. Thus it suggested that accurate measurement of crystal temperature factors could be achieved for medium-high or even medium resolution crystals by averaging over multiple data sets. Furthermore, we found that the correctly predicted active sites included not only the more flexible residues, but also some more rigid residues. Both the flexible and the rigid residues in the active site played an important role in forming the active site residue network, covering the majority of the substrate binding residues. Therefore, this experimental prediction method may be useful for characterizing the binding site and the function of a protein, such as drug targeting.
15. Active site dynamics of toluene hydroxylation by cytochrome P-450
Energy Technology Data Exchange (ETDEWEB)
Hanzlik, R.P.; Kahhiing John Ling (Univ. of Kansas, Lawrence (United States))
1990-06-22
Rat liver cytochrome P-450 hydroxylates toluene to benzyl alcohol plus o-, m-, and p-cresol. Deuterated toluenes were incubated under saturating conditions with liver microsomes from phenobarbital-pretreated rats, and product yields and ratios were measured. Stepwise deuteration of the methyl leads to stepwise decreases in the alcohol/cresol ratio without changing the cresol isomer ratios. Extensive deuterium retention in the benzyl alcohols from PhCH{sub 2}D and PhCHD{sub 2} suggests there is a large intrinsic isotope effect for benzylic hydroxylation. After replacement of the third benzylic H by D, the drop in the alcohol/cresol ratio was particularly acute, suggsting that metabolic switching from D to H within the methyl group was easier than switching from the methyl to the ring. Comparison of the alcohol/cresol ratio for PhCH{sub 3} vs PhCD{sub 3} indicated a net isotope effect of 6.9 for benzylic hydroxylation. From product yield data for PhCH{sub 3} and PhCD{sub 3}, {sup D}V for benzyl alcohol formation is only 1.92, whereas {sup D}V for total product formation is 0.67 (i.e., inverse). From competitive incubations of PhCH{sub 3}/PhCD{sub 3} mixtures {sup D}(V/K) isotope effects on benzyl alcohol formation and total product formation (3.6 and 1.23, respectively) are greatly reduced, implying strong commitment to catalysis. In contrast, {sup D}(V/K) for the alcohol/cresol ratio is 6.3, indicating that the majority of the intrinsic isotope effect is expressed through metabolic switching. Overall, these data are consistent with reversible formation of a complex between toluene and the active oxygen form of cytochrome P-450, which rearranges internally and reacts to form products faster than it dissociates back to release substrate.
16. 1993 annual report of hazardous waste activities for the Oak Ridge K-25 site
Energy Technology Data Exchange (ETDEWEB)
1994-02-01
This report is a detailed listing of all of the Hazardous Waste activities occurring at Martin Mariettas K-25 site. Contained herein are hazardous waste notification forms, waste stream reports, generator fee forms and various TSDR reports.
17. 1993 annual report of hazardous waste activities for the Oak Ridge K-25 site
Energy Technology Data Exchange (ETDEWEB)
1994-02-01
This report is a detailed listing of all of the Hazardous Waste activities occurring at Martin Mariettas K-25 site. Contained herein are hazardous waste notification forms, waste stream reports, generator fee forms and various TSDR reports.
18. XAFS Study of the Photo-Active Site of Mo/MCM-41
Science.gov (United States)
Miyamoto, Daisuke; Ichikuni, Nobuyuki; Shimazu, Shogo
2007-02-01
An Mo/MCM-41 catalyst was prepared and used for study of propene and 1-butene photo-metathesis reactions. XAFS analysis revealed that hydrogen reduction leads to a decreased role for the Mo=O site. The Mo-O site plays an important role for the olefin photo-metathesis reaction on the H2 reduced Mo/MCM-41. From EXAFS analysis, the active site of photo-metathesis reaction is the Mo=O part for oxidized Mo/MCM-41, whereas it is the Mo-O site for reduced Mo/MCM-41.
19. 'Unconventional' coordination chemistry by metal chelating fragments in a metalloprotein active site.
Science.gov (United States)
Martin, David P; Blachly, Patrick G; Marts, Amy R; Woodruff, Tessa M; de Oliveira, César A F; McCammon, J Andrew; Tierney, David L; Cohen, Seth M
2014-04-01
The binding of three closely related chelators: 5-hydroxy-2-methyl-4H-pyran-4-thione (allothiomaltol, ATM), 3-hydroxy-2-methyl-4H-pyran-4-thione (thiomaltol, TM), and 3-hydroxy-4H-pyran-4-thione (thiopyromeconic acid, TPMA) to the active site of human carbonic anhydrase II (hCAII) has been investigated. Two of these ligands display a monodentate mode of coordination to the active site Zn(2+) ion in hCAII that is not recapitulated in model complexes of the enzyme active site. This unprecedented binding mode in the hCAII-thiomaltol complex has been characterized by both X-ray crystallography and X-ray spectroscopy. In addition, the steric restrictions of the active site force the ligands into a 'flattened' mode of coordination compared with inorganic model complexes. This change in geometry has been shown by density functional computations to significantly decrease the strength of the metal-ligand binding. Collectively, these data demonstrate that the mode of binding by small metal-binding groups can be significantly influenced by the protein active site. Diminishing the strength of the metal-ligand bond results in unconventional modes of metal coordination not found in typical coordination compounds or even carefully engineered active site models, and understanding these effects is critical to the rational design of inhibitors that target clinically relevant metalloproteins.
20. Poisoning Experiments Aimed at Discriminating Active and Less-Active Sites of Silica-Supported Tantalum Hydride for Alkane Metathesis
KAUST Repository
Saggio, Guillaume
2010-10-04
Only 50% of the silica-supported tantalum hydride sites are active in the metathesis of propane. Indeed, more than 45% of the tantalum hydride can be eliminated by a selective oxygen poisoning of inactive sites with no significant decrease in the global turnover. Conversely, cyclopentane induces no such selective poisoning. Hence, the active tantalum hydride sites that show greater resistance to oxygen poisoning correspond to the νTa-H bands of higher wavenumbers, particularly that at 1860cm-1. These active tantalum hydride sites should correspond to tris- or monohydride species relatively far from silica surface oxygen atoms. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
1. Highly selective adsorption of ethylene over ethane in a MOF featuring the combination of open metal site and π-complexation.
Science.gov (United States)
Zhang, Yiming; Li, Baiyan; Krishna, Rajamani; Wu, Zili; Ma, Dingxuan; Shi, Zhan; Pham, Tony; Forrest, Katherine; Space, Brian; Ma, Shengqian
2015-02-14
The introduction of the combination of open metal site (OMS) and π-complexation into MOF has led to very high ethylene-ethane adsorption selectivity at 318 K, as illustrated in the context of MIL-101-Cr-SO3Ag. The interactions with ethylene from both OMS and π-complexation in MIL-101-Cr-SO3Ag have been investigated by in situ IR spectroscopic studies and computational calculations, which suggest that π-complexation contributes dominantly to the high ethylene-ethane adsorption selectivity.
2. Concept for calculating dose rates from activated groundwater at accelerator sites
CERN Document Server
Prolingheuer, N; Vanderborght, J; Schlögl, B; Nabbi, R; Moormann, R
Licensing of particle accelerators requires the proof that the groundwater outside of the site will not be significantly contaminated by activation products formed below accelerator and target. In order to reduce the effort for this proof, a site independent simplified but conservative method is under development. The conventional approach for calculation of activation of soil and groundwater is shortly described on example of a site close to Forschungszentrum Juelich, Germany. Additionally an updated overview of a data library for partition coefficients for relevant nuclides transported in the aquifer at the site is presented. The approximate model for transport of nuclides with ground water including exemplary results on nuclide concentrations outside of the site boundary and of resulting effective doses is described. Further applications and developments are finally outlined.
3. Extraordinary Separation of Acetylene-Containing Mixtures with Microporous Metal-Organic Frameworks with Open O Donor Sites and Tunable Robustness through Control of the Helical Chain Secondary Building Units
KAUST Repository
Yao, Zizhu
2016-03-02
Acetylene separation is a very important but challenging industrial separation task. Here, through the solvothermal reaction of CuI and 5-triazole isophthalic acid in different solvents, two metal-organic frameworks (MOFs, FJU-21 and FJU-22) with open O donor sites and controllable robustness have been obtained for acetylene separation. They contain the same paddle-wheel {Cu2(COO2)4} nodes and metal-ligand connection modes, but with different helical chains as secondary building units (SBUs), leading to different structural robustness for the MOFs. FJU-21 and FJU-22 are the first examples in which the MOFs\\' robustness is controlled by adjusting the helical chain SBUs. Good robustness gives the activated FJU-22 a, which has higher surface area and gas uptakes than the flexible FJU-21 a. Importantly, FJU-22 a shows extraordinary separation of acetylene mixtures under ambient conditions. The separation capacity of FJU-22 a for 50:50 C2H2/CO2 mixtures is about twice that of the high-capacity HOF-3, and its actual separation selectivity for C2H2/C2H4 mixtures containing 1 % acetylene is the highest among reported porous materials. Based on first-principles calculations, the extraordinary separation performance of C2H2 for FJU-22 a was attributed to hydrogen-bonding interactions between the C2H2 molecules with the open O donors on the wall, which provide better recognition ability for C2H2 than other functional sites, including open metal sites and amino groups. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
4. Extraordinary Separation of Acetylene-Containing Mixtures with Microporous Metal-Organic Frameworks with Open O Donor Sites and Tunable Robustness through Control of the Helical Chain Secondary Building Units.
Science.gov (United States)
Yao, Zizhu; Zhang, Zhangjing; Liu, Lizhen; Li, Ziyin; Zhou, Wei; Zhao, Yunfeng; Han, Yu; Chen, Banglin; Krishna, Rajamani; Xiang, Shengchang
2016-04-11
Acetylene separation is a very important but challenging industrial separation task. Here, through the solvothermal reaction of CuI and 5-triazole isophthalic acid in different solvents, two metal-organic frameworks (MOFs, FJU-21 and FJU-22) with open O donor sites and controllable robustness have been obtained for acetylene separation. They contain the same paddle-wheel {Cu2(COO2)4} nodes and metal-ligand connection modes, but with different helical chains as secondary building units (SBUs), leading to different structural robustness for the MOFs. FJU-21 and FJU-22 are the first examples in which the MOFs' robustness is controlled by adjusting the helical chain SBUs. Good robustness gives the activated FJU-22 a, which has higher surface area and gas uptakes than the flexible FJU-21 a. Importantly, FJU-22 a shows extraordinary separation of acetylene mixtures under ambient conditions. The separation capacity of FJU-22 a for 50:50 C2H2/CO2 mixtures is about twice that of the high-capacity HOF-3, and its actual separation selectivity for C2H2/C2H4 mixtures containing 1% acetylene is the highest among reported porous materials. Based on first-principles calculations, the extraordinary separation performance of C2H2 for FJU-22 a was attributed to hydrogen-bonding interactions between the C2H2 molecules with the open O donors on the wall, which provide better recognition ability for C2H2 than other functional sites, including open metal sites and amino groups.
5. Mixing active-site components: a recipe for the unique enzymatic activity of a telomere resolvase.
Science.gov (United States)
2004-09-21
The ResT protein, a telomere resolvase from Borrelia burgdorferi, processes replication intermediates into linear replicons with hairpin ends by using a catalytic mechanism similar to that for tyrosine recombinases and type IB topoisomerases. We have identified in ResT a hairpin binding region typically found in cut-and-paste transposases. We show that substitution of residues within this region results in a decreased ability of these mutants to catalyze telomere resolution. However, the mutants are capable of resolving heteroduplex DNA substrates designed to allow spontaneous destabilization and prehairpin formation. These findings support the existence of a hairpin binding region in ResT, the only known occurrence outside a transposase. The combination of transposase-like and tyrosine-recombinase-like domains found in ResT indicates the use of a composite active site and helps explain the unique breakage-and-reunion reaction observed with this protein. Comparison of the ResT sequence with other known telomere resolvases suggests that a hairpin binding motif is a common feature in this class of enzyme; the sequence motif also appears in the RAG recombinases. Finally, our data support a mechanism of action whereby ResT induces prehairpin formation before the DNA cleavage step.
6. Temporal Analysis of Activity Patterns of Editors in Collaborative Mapping Project of OpenStreetMap
CERN Document Server
2013-01-01
In the recent years Wikis have become an attractive platform for social studies of the human behaviour. Containing millions records of edits across the globe, collaborative systems such as Wikipedia have allowed researchers to gain a better understanding of editors participation and their activity patterns. However, contributions made to Geo-wikis_wiki-based collaborative mapping projects_ differ from systems such as Wikipedia in a fundamental way due to spatial dimension of the content that limits the contributors to a set of those who posses local knowledge about a specific area and therefore cross-platform studies and comparisons are required to build a comprehensive image of online open collaboration phenomena. In this work, we study the temporal behavioural pattern of OpenStreetMap editors, a successful example of geo-wiki, for two European capital cities. We categorise different type of temporal patterns and report on the historical trend within a period of 7 years of the project age. We also draw a com...
7. Correlated structural kinetics and retarded solvent dynamics at the metalloprotease active site
Energy Technology Data Exchange (ETDEWEB)
Grossman, Moran; Born, Benjamin; Heyden, Matthias; Tworowski, Dmitry; Fields, Gregg B.; Sagi, Irit; Havenith, Martina
2011-09-18
Solvent dynamics can play a major role in enzyme activity, but obtaining an accurate, quantitative picture of solvent activity during catalysis is quite challenging. Here, we combine terahertz spectroscopy and X-ray absorption analyses to measure changes in the coupled water-protein motions during peptide hydrolysis by a zinc-dependent human metalloprotease. These changes were tightly correlated with rearrangements at the active site during the formation of productive enzyme-substrate intermediates and were different from those in an enzyme–inhibitor complex. Molecular dynamics simulations showed a steep gradient of fast-to-slow coupled protein-water motions around the protein, active site and substrate. Our results show that water retardation occurs before formation of the functional Michaelis complex. We propose that the observed gradient of coupled protein-water motions may assist enzyme-substrate interactions through water-polarizing mechanisms that are remotely mediated by the catalytic metal ion and the enzyme active site.
8. Structural and Kinetic Analyses of Macrophage Migration Inhibitory Factor Active Site Interactions
Energy Technology Data Exchange (ETDEWEB)
Crichlow, G.; Lubetsky, J; Leng, L; Bucala, R; Lolis, E
2009-01-01
Macrophage migration inhibitory factor (MIF) is a secreted protein expressed in numerous cell types that counters the antiinflammatory effects of glucocorticoids and has been implicated in sepsis, cancer, and certain autoimmune diseases. Interestingly, the structure of MIF contains a catalytic site resembling the tautomerase/isomerase sites of microbial enzymes. While bona fide physiological substrates remain unknown, model substrates have been identified. Selected compounds that bind in the tautomerase active site also inhibit biological functions of MIF. It had previously been shown that the acetaminophen metabolite, N-acetyl-p-benzoquinone imine (NAPQI), covalently binds to the active site of MIF. In this study, kinetic data indicate that NAPQI inhibits MIF both covalently and noncovalently. The structure of MIF cocrystallized with NAPQI reveals that the NAPQI has undergone a chemical alteration forming an acetaminophen dimer (bi-APAP) and binds noncovalently to MIF at the mouth of the active site. We also find that the commonly used protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), forms a covalent complex with MIF and inhibits the tautomerase activity. Crystallographic analysis reveals the formation of a stable, novel covalent bond for PMSF between the catalytic nitrogen of the N-terminal proline and the sulfur of PMSF with complete, well-defined electron density in all three active sites of the MIF homotrimer. Conclusions are drawn from the structures of these two MIF-inhibitor complexes regarding the design of novel compounds that may provide more potent reversible and irreversible inhibition of MIF.
9. A large gap opening of graphene induced by the adsorption of CO on the Al-doped site.
Science.gov (United States)
2013-08-01
We investigated CO adsorption on the pristine, Stone-Wales (SW) defected, Al- and Si- doped graphenes by using density functional calculations in terms of geometric, energetic and electronic properties. It was found that CO molecule is weakly adsorbed on the pristine and SW defected graphenes and their electronic properties were slightly changed. The Al- and Si- doped graphenes show high reactivity toward CO, so calculated adoption energies are about -11.40 and -13.75 kcal mol(-1) in the most favorable states. It was found that, among all the structures, the electronic properties of Al-doped graphene are strongly sensitive to the presence of CO molecule. We demonstrate the existence of a large Eg opening of 0.87 eV in graphene which is induced by Al-doping and CO adsorption.
10. The Relationship of Children Connectivity and Physical Activities with Satisfaction of Open Spaces in High Rise Apartments in Tehran
Directory of Open Access Journals (Sweden)
Ali Sharghi
2014-07-01
Full Text Available Increase of urbanization has pressure on the urban children's lives and physical activities. While in designing of residential apartments’ open spaces, there is little attention to the children. The children, who live in the high-rise apartments found to have less physical activities. However, supposedly, children need to engage in the physical activity in the outdoor areas as WHO recommend that children take part in at least one hour of moderate physical activity in every day. This paper firstly, reviews different researches in this area. Then, it attempts to find children’s satisfaction regarding connectivity to open spaces as a dependent variable and their preferred activities, perceived safety, and familiarity about connectivity to open spaces as independent variables. The method of study is a semi-interview survey with 80 children between 6 and 12 years old (primary school ages in two cases in Tehran. The result of this research shows that children satisfaction from open space has an effect on their outdoor activities. Therefore, the designers should be considering children physical activities needs in open spaces.
11. Open Discussion Session: Challenges and Advancements in Coordinated Space Weather Activities
Science.gov (United States)
Kauristie, Kirsti
2016-07-01
Besides addressing the key questions in space weather research the Cospar/ILWS Roadmap presents also recommendations for teaming in the research environment and for collaboration between agencies and communities. Coordinated work of different research groups facilitate our efforts for a holistic view on the entire Sun-Earth system with its complicated feedback processes in different scale sizes. Seamless knowledge transfer from research to operational services is a crucial factor for the success of space weather research field. In this open discussion session we encourage the participants to share their views on most important challenges and advancements in our field, both in science and in collaboration. We also welcome comments on the roadmap recommendations and guidance for similar activities in the future.
12. Evaluating the dynamical characteristics of particle matter emissions in an open ore yard with industrial operation activities.
Science.gov (United States)
Cong, X C; Yang, G S; Qu, J H; Dai, M X
2016-11-01
A study to investigate the dynamical characteristics of particle matter emissions in a working open yard is conducted in Caofeidian Port of Hebei Province, China. The average diurnal concentrations of the total suspended particulate (TSP) matter and respirable particulate matter (PM10 and PM5) are monitored during the field measurement campaign. Sampling is performed at a regular interval at 8 monitoring stations in the yard with normal industrial activities. The average TSP, PM10 and PM5 concentrations range from 285 to 568, 198 to 423 and 189 to 330 μg.m-3 in the yard, respectively. The linear regression correlation coefficient of TSP/PM10 and TSP/PM5 is 0.95±0.01 and 0.88±0.02, respectively.By using the Spearman correlation method, the wind speed and relative humidity are both weakly correlated with the PM10 and PM5 concentrations according to the measurements. In addition, industrial operation activities, such as vehicular traffic in the yard and the loading time of stackers, are significantly positively correlated with the PM concentration. Using the multivariate regression method, the main parameters influencing the TSP concentration variations are integratedly analysed. The traffic volume is found to be a significant predictor of TSP concentration variation, with the smallest P value (Pindustrial activities in the yard is proposed. The dynamical emissions average 5.25x10(5) kg.year(-1) and EFD is evaluated to be 0.29 kg.(ton.day)(-1) during the measurement period. These outcomes have meaningful implications not only for understanding the dynamical characteristics of particle emissions in the working stockyard but also for implementing effective control measures at appropriate sites in the harbour area.
13. Dynamics of an Active-Site Flap Contributes to Catalysis in a JAMM Family Metallo Deubiquitinase.
Science.gov (United States)
Bueno, Amy N; Shrestha, Rashmi K; Ronau, Judith A; Babar, Aditya; Sheedlo, Michael J; Fuchs, Julian E; Paul, Lake N; Das, Chittaranjan
2015-10-06
The endosome-associated deubiquitinase (DUB) AMSH is a member of the JAMM family of zinc-dependent metallo isopeptidases with high selectivity for Lys63-linked polyubiquitin chains, which play a key role in endosomal-lysosomal sorting of activated cell surface receptors. The catalytic domain of the enzyme features a flexible flap near the active site that opens and closes during its catalytic cycle. Structural analysis of its homologues, AMSH-LP (AMSH-like protein) and the fission yeast counterpart, Sst2, suggests that a conserved Phe residue in the flap may be critical for substrate binding and/or catalysis. To gain insight into the contribution of this flap in substrate recognition and catalysis, we generated mutants of Sst2 and characterized them using a combination of enzyme kinetics, X-ray crystallography, molecular dynamics simulations, and isothermal titration calorimetry (ITC). Our analysis shows that the Phe residue in the flap contributes key interactions during the rate-limiting step but not to substrate binding, since mutants of Phe403 exhibit a defect only in kcat but not in KM. Moreover, ITC studies show Phe403 mutants have similar KD for ubiquitin compared to the wild-type enzyme. The X-ray structures of both Phe403Ala and the Phe403Trp, in both the free and ubiquitin bound form, reveal no appreciable structural change that might impair substrate or alter product binding. We observed that the side chain of the Trp residue is oriented identically with respect to the isopeptide moiety of the substrate as the Phe residue in the wild-type enzyme, so the loss of activity seen in this mutant cannot be explained by the absence of a group with the ability to provide van der Waals interactions that facilitate the hyrdolysis of the Lys63-linked diubiquitin. Molecular dynamics simulations indicate that the flap in the Trp mutant is quite flexible, allowing almost free rotation of the indole side chain. Therefore, it is possible that these different dynamic
14. Open clusters as laboratories for stellar spin-down and magnetic activity decay
Science.gov (United States)
Douglas, Stephanie; Agueros, Marcel A.; Covey, Kevin R.
2017-01-01
The oldest open clusters within 250 pc of the Sun, the Hyades and Praesepe, are important benchmarks for calibrating stellar properties such as rotation and magnetic activity. As they have the same age and roughly solar metallicity, these clusters serve as an ideal laboratory for testing the agreement between theoretical and empirical rotation-activity relations at ~600 Myr. The repurposed Kepler mission, K2, has allowed us to measure rotation periods for dozens of Hyads and hundreds of Praesepe members, including the first periods measured for fully convective Hyads. These data have enabled new tests of models describing the evolution of stellar rotation; discrepancies with these models imply that we still do not fully understand how magnetic fields affect stellar spin-down. I will present rotation periods measured for 48 Hyads and 699 Praesepe members with K2, along with associated Halpha and X-ray fluxes. I will also show how we can compare the dependence of H-alpha and X-ray emission on rotation in order to test theories of magnetic field topology and stellar dynamos. These tests inform models of stellar wind-driven angular momentum loss and the age-rotation-activity relation.
15. Open label trial of granulocyte apheresis suggests therapeutic efficacy in chronically active steroid refractory ulcerative colitis
Institute of Scientific and Technical Information of China (English)
Wolfgang Kruis; Robert L(o)fberg; Axel Dignass; Elisabeth Steinhagen-Thiessen; Julia Morgenstern; Joachim M(o)ssner; Stephan Schreiber; Maurizio Vecchi; Alberto Malesci; Max Reinshagen
2005-01-01
AIM:To study the efficacy, safety, and feasibility of a granulocyte adsorptive type apheresis system for the treatment of patients with chronically active ulcerative colitis despite standard therapy.METHODS: An open label multicenter study was carried out in 39 patients with active ulcerative colitis (CAI6-8) despite continuous use of steroids (a minimum total dose of 400 mg prednisone within the last 4 wk).Patients received a total of five aphereses using a granulocyte adsorptive technique (Adacolumn(R), Otsuka Pharmaceutical Europe, UK). Assessments at wk 6 and during follow-up until 4 mo comprised clinical (CAI) and endoscopic (EI) activity index, histology, quality of life(IBDQ), and laboratory tests.RESULTS: Thirty-five out of thirty-nine patients were qualified for intent-to-treat analysis. After the apheresis treatment at wk 6, 13/35 (37.1%) patients achieved clinical remission and 10/35 (28.6%) patients had endoscopic remission (CAI＜4, EI＜4). Quality of life (IBDQ) increased significantly (24 points, P＜0.01)at wk 6. Apheresis could be performed in all but one patient. Aphereses were well tolerated, only one patient experienced anemia.CONCLUSION: In patients with steroid refractory ulcerative colitis, five aphereses with a granulocyte/monocyte depleting filter show potential short-term efficacy. Tolerability and technical feasibility of the procedure are excellent.
16. STIM1 activates CRAC channels through rotation of the pore helix to open a hydrophobic gate
Science.gov (United States)
Yamashita, Megumi; Yeung, Priscilla S.-W.; Ing, Christopher E.; McNally, Beth A.; Pomès, Régis; Prakriya, Murali
2017-02-01
Store-operated Ca2+ release-activated Ca2+ (CRAC) channels constitute a major pathway for Ca2+ influx and mediate many essential signalling functions in animal cells, yet how they open remains elusive. Here, we investigate the gating mechanism of the human CRAC channel Orai1 by its activator, stromal interacting molecule 1 (STIM1). We find that two rings of pore-lining residues, V102 and F99, work together to form a hydrophobic gate. Mutations of these residues to polar amino acids produce channels with leaky gates that conduct ions in the resting state. STIM1-mediated channel activation occurs through rotation of the pore helix, which displaces the F99 residues away from the pore axis to increase pore hydration, allowing ions to flow through the V102-F99 hydrophobic band. Pore helix rotation by STIM1 also explains the dynamic coupling between CRAC channel gating and ion selectivity. This hydrophobic gating mechanism has implications for CRAC channel function, pharmacology and disease-causing mutations.
17. Activity after Site-Directed Mutagenesis of CD59 on Complement-Mediated Cytolysis
Institute of Scientific and Technical Information of China (English)
Xinhong Zhu; Meihua Gao; Shurong Ren; Qiubo Wang; Cunzhi Lin
2008-01-01
CD59 may inhibit the cytolytic activity of complement by binding to C8/C9 and protect host cell membranes against homologous membrane attack complex (MAC). However, CD59 is widely overexpressed on tumor cells,which has been implicated in tumorigenesis. The active site of CD59 relative to MAC is still confused. As reported the MAC binding site is located in the vicinity of a hydrophobic groove on the membrane distal face of the protein centered around residue W40. Here two site-directed mutagenesis were performed by overlapping extension PCR to delete residue W40 site (Mutant 1, M1) or to change C39W40K41 to W39W40W41 (Mutant 2, M2). Then we constructed mutant CD59 eukaryotic expression system and investigated their biological function on CHO cells compared with wild-type CD59. Stable populations of CHO cells expressing recombinant proteins were screened by immunotechnique. After 30 passages culturing, proteins could be tested. Dye release assays suggest that M1CD59 loses the activity against complement, while M2CD59 increases the anti-complement activity slightly.Results indicate that W40 of human CD59 is important to its activity, and prohibition of this site may be a potential way to increase complement activity and to treat tumors.
18. Tuning magnetic critical behaviour in Ti-manganites by doping with vacancies in A-sites: Sr{sub 1-x}{open_square}{sub x}LaMnTiO{sub 6-{delta}} (0 < x {<=} 0.15)
Energy Technology Data Exchange (ETDEWEB)
2011-10-17
Highlights: {yields} Pure polycrystalline powders of Sr{sub 1-x}{open_square}{sub x}LaMnTiO{sub 6-{delta}} perovskites have been synthesized by the liquid mix technique. {yields} X-ray and neutron diffraction data, together with HRTEM are interpreted in terms of tetragonal symmetry and S.G. I4/mcm, being all the cations located at random in each sublattice. {yields} Magnetization measurements show the existence of a frustrated behaviour, implying FM interactions at low temperatures, and semiconductor behaviour is observed in the whole temperature range explored. {yields} The introduction of vacancies in the A sites is connected to the stabilization of the Griffiths phase for x < 0.15, and an electronic model considering a cluster glass picture is proposed. - Abstract: Microcrystalline powders of Sr{sub 1-x}{open_square}{sub x}LaMnTiO{sub 6-{delta}} (0 {<=} x {<=} 0.15) perovskites have been synthesized by the sol-gel method. Structural characterization from neutron diffraction data shows tetragonal symmetry for all samples in the whole temperature range explored (5-700 K) and HRTEM analysis confirms it at the micro scale. Structural refinements suggest that Sr/La and Mn/Ti cations are placed at random in A and B sublattices, respectively, being the vacancies exclusively located on the former sites. Doping with vacancies in the A sites does not provoke any extra structural ordering or distortion but modifies the electronic scenario at the B-sites, leading to an enhancement of Griffiths phase as the amount of vacancies, x, increases. Semiconductor behaviour has been observed, without any transition to metallic state, with typical activation energies of 0.15 eV. The intrinsic magnetic frustrated behaviour is described in terms of a cluster-glass model.
19. Cyanide does more to inhibit heme enzymes, than merely serving as an active-site ligand
Energy Technology Data Exchange (ETDEWEB)
Parashar, Abhinav [Center for Biomedical Research, VIT University, Vellore, Tamil Nadu, 632014 India (India); Venkatachalam, Avanthika [REDOx Lab, PSG Institute of Advanced Studies, Avinashi Road, Peelamedu, Coimbatore, Tamil Nadu, 641004 (India); Gideon, Daniel Andrew [Center for Biomedical Research, VIT University, Vellore, Tamil Nadu, 632014 India (India); Manoj, Kelath Murali, E-mail: [email protected] [REDOx Lab, PSG Institute of Advanced Studies, Avinashi Road, Peelamedu, Coimbatore, Tamil Nadu, 641004 (India)
2014-12-12
Highlights: • Cyanide (CN) is a well-studied toxic principle, known to inhibit heme-enzymes. • Inhibition is supposed to result from CN binding at the active site as a ligand. • Diverse heme enzymes’ CN inhibition profiles challenge prevailing mechanism. • Poor binding efficiency of CN at low enzyme concentrations and ligand pressures. • CN-based diffusible radicals cause ‘non-productive electron transfers’ (inhibition). - Abstract: The toxicity of cyanide is hitherto attributed to its ability to bind to heme proteins’ active site and thereby inhibit their activity. It is shown herein that the long-held interpretation is inadequate to explain several observations in heme-enzyme reaction systems. Generation of cyanide-based diffusible radicals in heme-enzyme reaction milieu could shunt electron transfers (by non-active site processes), and thus be detrimental to the efficiency of oxidative outcomes.
20. Conformational Change in the Active Site of Streptococcal Unsaturated Glucuronyl Hydrolase Through Site-Directed Mutagenesis at Asp-115.
Science.gov (United States)
Nakamichi, Yusuke; Oiki, Sayoko; Mikami, Bunzo; Murata, Kousaku; Hashimoto, Wataru
2016-08-01
Bacterial unsaturated glucuronyl hydrolase (UGL) degrades unsaturated disaccharides generated from mammalian extracellular matrices, glycosaminoglycans, by polysaccharide lyases. Two Asp residues, Asp-115 and Asp-175 of Streptococcus agalactiae UGL (SagUGL), are completely conserved in other bacterial UGLs, one of which (Asp-175 of SagUGL) acts as a general acid and base catalyst. The other Asp (Asp-115 of SagUGL) also affects the enzyme activity, although its role in the enzyme reaction has not been well understood. Here, we show substitution of Asp-115 in SagUGL with Asn caused a conformational change in the active site. Tertiary structures of SagUGL mutants D115N and D115N/K370S with negligible enzyme activity were determined at 2.00 and 1.79 Å resolution, respectively, by X-ray crystallography. The side chain of Asn-115 is drastically shifted in both mutants owing to the interaction with several residues, including Asp-175, by formation of hydrogen bonds. This interaction between Asn-115 and Asp-175 probably prevents the mutants from triggering the enzyme reaction using Asp-175 as an acid catalyst.
1. Serine-202 is the putative precursor of the active site dehydroalanine of phenylalanine ammonia lyase. Site-directed mutagenesis studies on the enzyme from parsley (Petroselinum crispum L.).
Science.gov (United States)
Schuster, B; Rétey, J
1994-08-01
To investigate the possible role of serine as a precursor of dehydroalanine at the active site of phenylalanine ammonia lyase, two serines, conserved in all known PAL and histidase sequences, were changed to alanine by site-directed mutagenesis. The resulting mutant genes were subcloned into the expression vector pT7.7 and the gene products were assayed for PAL activity. Mutant PALMutS209A showed the same catalytic property as wild-type PAL, whereas mutant PALMutS202A was devoid of catalytic activity, indicating that serine-202 is the most likely precursor of the active site dehydroalanine.
2. Language Learning Activities of Distance EFL Learners in the Turkish Open Education System as the Indicator of Their Learner Autonomy
Science.gov (United States)
Altunay, Dilek
2013-01-01
This study investigates the noncompulsory language learning activities performed by a group of distance EFL learners in the Turkish Open Education System. Performance of these activities has been considered as an indicator of their learner autonomy. The data were collected through an online questionnaire and interviews. The study shows that in…
3. Sites of regulated phosphorylation that control K-Cl cotransporter activity.
Science.gov (United States)
Rinehart, Jesse; Maksimova, Yelena D; Tanis, Jessica E; Stone, Kathryn L; Hodson, Caleb A; Zhang, Junhui; Risinger, Mary; Pan, Weijun; Wu, Dianqing; Colangelo, Christopher M; Forbush, Biff; Joiner, Clinton H; Gulcicek, Erol E; Gallagher, Patrick G; Lifton, Richard P
2009-08-07
Modulation of intracellular chloride concentration ([Cl(-)](i)) plays a fundamental role in cell volume regulation and neuronal response to GABA. Cl(-) exit via K-Cl cotransporters (KCCs) is a major determinant of [Cl(-)](I); however, mechanisms governing KCC activities are poorly understood. We identified two sites in KCC3 that are rapidly dephosphorylated in hypotonic conditions in cultured cells and human red blood cells in parallel with increased transport activity. Alanine substitutions at these sites result in constitutively active cotransport. These sites are highly phosphorylated in plasma membrane KCC3 in isotonic conditions, suggesting that dephosphorylation increases KCC3's intrinsic transport activity. Reduction of WNK1 expression via RNA interference reduces phosphorylation at these sites. Homologous sites are phosphorylated in all human KCCs. KCC2 is partially phosphorylated in neonatal mouse brain and dephosphorylated in parallel with KCC2 activation. These findings provide insight into regulation of [Cl(-)](i) and have implications for control of cell volume and neuronal function.
4. Microparticle production, neutrophil activation, and intravascular bubbles following open-water SCUBA diving.
Science.gov (United States)
Thom, Stephen R; Milovanova, Tatyana N; Bogush, Marina; Bhopale, Veena M; Yang, Ming; Bushmann, Kim; Pollock, Neal W; Ljubkovic, Marko; Denoble, Petar; Dujic, Zeljko
2012-04-01
The goal of this study was to evaluate annexin V-positive microparticles (MPs) and neutrophil activation in humans following decompression from open-water SCUBA diving with the hypothesis that changes are related to intravascular bubble formation. Sixteen male volunteer divers followed a uniform profile of four daily SCUBA dives to 18 m of sea water for 47 min. Blood was obtained prior to and at 80 min following the first and fourth dives to evaluate the impact of repetitive diving, and intravascular bubbles were quantified by trans-thoracic echocardiography carried out at 20-min intervals for 2 h after each dive. MPs increased by 3.4-fold after each dive, neutrophil activation occurred as assessed by surface expression of myeloperoxidase and the CD18 component of β(2)-integrins, and there was an increased presence of the platelet-derived CD41 protein on the neutrophil surface indicating interactions with platelet membranes. Intravascular bubbles were detected in all divers. Surprisingly, significant inverse correlations were found among postdiving bubble scores and MPs, most consistently at 80 min or more after the dive on the fourth day. There were significant positive correlations between MPs and platelet-neutrophil interactions after the first dive and between platelet-neutrophil interactions and neutrophil activation documented as an elevation in β(2)-integrin expression after the fourth dive. We conclude that MPs- and neutrophil-related events in humans are consistent with findings in an animal decompression model. Whether there are causal relationships among bubbles, MPs, platelet-neutrophil interactions, and neutrophil activation remains obscure and requires additional study.
5. Crystal structure of an avian influenza polymerase PA[subscript N] reveals an endonuclease active site
Energy Technology Data Exchange (ETDEWEB)
Yuan, Puwei; Bartlam, Mark; Lou, Zhiyong; Chen, Shoudeng; Zhou, Jie; He, Xiaojing; Lv, Zongyang; Ge, Ruowen; Li, Xuemei; Deng, Tao; Fodor, Ervin; Rao, Zihe; Liu, Yingfang; (NU Sinapore); (Nankai); (Oxford); (Chinese Aca. Sci.); (Tsinghua)
2009-11-10
The heterotrimeric influenza virus polymerase, containing the PA, PB1 and PB2 proteins, catalyses viral RNA replication and transcription in the nucleus of infected cells. PB1 holds the polymerase active site and reportedly harbours endonuclease activity, whereas PB2 is responsible for cap binding. The PA amino terminus is understood to be the major functional part of the PA protein and has been implicated in several roles, including endonuclease and protease activities as well as viral RNA/complementary RNA promoter binding. Here we report the 2.2 angstrom (A) crystal structure of the N-terminal 197 residues of PA, termed PA(N), from an avian influenza H5N1 virus. The PA(N) structure has an alpha/beta architecture and reveals a bound magnesium ion coordinated by a motif similar to the (P)DX(N)(D/E)XK motif characteristic of many endonucleases. Structural comparisons and mutagenesis analysis of the motif identified in PA(N) provide further evidence that PA(N) holds an endonuclease active site. Furthermore, functional analysis with in vivo ribonucleoprotein reconstitution and direct in vitro endonuclease assays strongly suggest that PA(N) holds the endonuclease active site and has critical roles in endonuclease activity of the influenza virus polymerase, rather than PB1. The high conservation of this endonuclease active site among influenza strains indicates that PA(N) is an important target for the design of new anti-influenza therapeutics.
6. Substrate Shuttling Between Active Sites of Uroporphyrinogen Decarboxylase in Not Required to Generate Coproporphyrinogen
Energy Technology Data Exchange (ETDEWEB)
Phillips, J.; Warby, C; Whitby, F; Kushner, J; Hill, C
2009-01-01
Uroporphyrinogen decarboxylase (URO-D; EC 4.1.1.37), the fifth enzyme of the heme biosynthetic pathway, is required for the production of heme, vitamin B12, siroheme, and chlorophyll precursors. URO-D catalyzes the sequential decarboxylation of four acetate side chains in the pyrrole groups of uroporphyrinogen to produce coproporphyrinogen. URO-D is a stable homodimer, with the active-site clefts of the two subunits adjacent to each other. It has been hypothesized that the two catalytic centers interact functionally, perhaps by shuttling of reaction intermediates between subunits. We tested this hypothesis by construction of a single-chain protein (single-chain URO-D) in which the two subunits were connected by a flexible linker. The crystal structure of this protein was shown to be superimposable with wild-type activity and to have comparable catalytic activity. Mutations that impaired one or the other of the two active sites of single-chain URO-D resulted in approximately half of wild-type activity. The distributions of reaction intermediates were the same for mutant and wild-type sequences and were unaltered in a competition experiment using I and III isomer substrates. These observations indicate that communication between active sites is not required for enzyme function and suggest that the dimeric structure of URO-D is required to achieve conformational stability and to create a large active-site cleft.
7. A Cultural-Historical Activity Theory Investigation of Contradictions in Open and Distance Higher Education among Alienated Adult Learners in Korea National Open University
Directory of Open Access Journals (Sweden)
K. P. Joo
2014-02-01
Full Text Available Drawing upon cultural-historical activity theory, this research analyzed the structural contradictions existing in a variety of educational activities among a group of alienated adult students in Korea National Open University (KNOU. Despite KNOU’s quantitative development in student enrollment, the contradictions shed light on how the institution’s top-down, bureaucratic pedagogical system collided with individual expectations and needs. In particular, the participants’ critical viewpoints demonstrate the incompatible social roles that the open and distance higher education institution plays in Korean society. For example, while KNOU contributes to extending higher education opportunities for those who have unmet educational needs, the value of the KNOU degree has not been socially acknowledged since there is little, if any, competition in the entrance process. This study also documents how these contradictions were culturally and historically embedded in the participants’ distance higher education activities. Given the persistent contradictions, the research findings illuminate that KNOU’s efficiency-oriented model has not effectively facilitated the students’ learning as its distance higher education system is inevitably based on a compromise between a competitive, quality curriculum and the efficient extension of audiences.
8. A conformational switch in the active site of BT_2972, a methyltransferase from an antibiotic resistant pathogen B. thetaiotaomicron.
Directory of Open Access Journals (Sweden)
Veerendra Kumar
Full Text Available Methylation is one of the most common biochemical reactions involved in cellular and metabolic functions and is catalysed by the action of methyltransferases. Bacteroides thetaiotaomicron is an antibiotic-resistant bacterium that confers resistance through methylation, and as yet, there is no report on the structure of methyltransferases from this bacterium. Here, we report the crystal structure of an AdoMet-dependent methyltransferase, BT_2972 and its complex with AdoMet and AdoHcy for B. thetaiotaomicron VPI-5482 strain along with isothermal titration calorimetric assessment of the binding affinities. Comparison of the apo and complexed BT_2972 structures reveals a significant conformational change between open and closed forms of the active site that presumably regulates the association with cofactors and may aid interaction with substrate. Together, our analysis suggests that BT_2972 is a small molecule methyltransferase and might catalyze two O-methylation reaction steps involved in the ubiquinone biosynthesis pathway.
9. Residents’ Environmental Conservation Behaviors at Tourist Sites: Broadening the Norm Activation Framework by Adopting Environment Attachment
OpenAIRE
Yuling Zhang; Jie Zhang; Yuyao Ye; Qitao Wu; Lixia Jin; Hongou Zhang
2016-01-01
Understanding the factors that affect residents’ environmental conservation behaviors help in managing the environment of tourist sites. This research provides an integrative understanding of how residents near tourist sites form their environmental conservation behaviors by merging the norm-activation model and cognitive-affective model into one theoretical framework. Results of the structural analysis from a sample of 642 residents showed that this study’s proposed composite model includes ...
10. Analysis and Parametric Investigation of Active Open Cross Section Thin Wall Beams
Science.gov (United States)
Griffiths, James
The static behaviour of active Open Cross Section Thin Wall Beams (OCSTWB) with embedded Active/Macro Fibre Composites (AFCs/MFCs) has been investigated for the purpose of advancing the fundamental theory needed in the development of advanced smart structures. An efficient code that can analyze active OCSTWB using analytical equations has been studied. Various beam examples have been investigated in order to verify this recently developed analytical active OCSTWB analysis tool. The cross sectional stiffness constants and induced force, moments and bimoment predicted by this analytical code have been compared with those predicted by the 2-D finite element beam cross section analysis codes called the Variational Asymptotic Beam Sectional (VABS) analysis and the University of Michigan VABS (UM/VABS). Good agreement was observed between the results obtained from the analytical tool and VABS. The calculated cross sectional stiffness constants and induced force/moments, the constitutive relation and the six intrinstic static equilibrium equations for OCSTWB were all used together in a first-order accurate forward difference scheme in order to determine the average twist and deflections along the beam span. In order to further verify the analytical code, the static behaviour of a number of beam examples was investigated using 3-D Finite Element Analysis (FEA). For a particular cross section, the rigid body twist and displacements were minimized with the displacements of all the nodes in the 3-D FEA model that compose the cross section. This was done for a number of cross sections along the beam span in order to recover the global beam twist and displacement profiles from the 3-D FEA results. The global twist and deflections predicted by the analytical code agreed closely with those predicted by UM/VABS and 3-D FEA. The study was completed by a parametric investigation to determine the boundary conditions and the composite ply lay-ups of the active and passive plies that
11. Spontaneous activation of visual pigments in relation to openness/closedness of chromophore-binding pocket
Science.gov (United States)
Yue, Wendy Wing Sze; Frederiksen, Rikard; Ren, Xiaozhi; Luo, Dong-Gen; Yamashita, Takahiro; Shichida, Yoshinori; Cornwall, M Carter; Yau, King-Wai
2017-01-01
Visual pigments can be spontaneously activated by internal thermal energy, generating noise that interferes with real-light detection. Recently, we developed a physicochemical theory that successfully predicts the rate of spontaneous activity of representative rod and cone pigments from their peak-absorption wavelength (λmax), with pigments having longer λmax being noisier. Interestingly, cone pigments may generally be ~25 fold noisier than rod pigments of the same λmax, possibly ascribed to an ‘open’ chromophore-binding pocket in cone pigments defined by the capability of chromophore-exchange in darkness. Here, we show in mice that the λmax-dependence of pigment noise could be extended even to a mutant pigment, E122Q-rhodopsin. Moreover, although E122Q-rhodopsin shows some cone-pigment-like characteristics, its noise remained quantitatively predictable by the ‘non-open’ nature of its chromophore-binding pocket as in wild-type rhodopsin. The openness/closedness of the chromophore-binding pocket is potentially a useful indicator of whether a pigment is intended for detecting dim or bright light. DOI: http://dx.doi.org/10.7554/eLife.18492.001 PMID:28186874
12. Modified Active Site Coordination in a Clinical Mutant of Sulfite Oxidase
Energy Technology Data Exchange (ETDEWEB)
Doonan, C.J.; Wilson, H.L.; Rajagopalan, K.V.; Garrett, R.M.; Bennett, B.; Prince, R.C.; George, G.N.
2009-06-02
The molybdenum site of the Arginine 160 {yields} Glutamine clinical mutant of the physiologically vital enzyme sulfite oxidase has been investigated by a combination of X-ray absorption spectroscopy and density functional theory calculations. We conclude that the mutant enzyme has a six-coordinate pseudo-octahedral active site with coordination of Glutamine O{sup {epsilon}} to molybdenum. This contrasts with the wild-type enzyme which is five-coordinate with approximately square-based pyramidal geometry. This difference in the structure of the molybdenum site explains many of the properties of the mutant enzyme which have previously been reported.
13. Solvent Tuning of Electrochemical Potentials in the Active Sites of HiPIP Versus Ferredoxin
Energy Technology Data Exchange (ETDEWEB)
Dey, A.; Francis, E.J.; Adams, M.W.W.; Babini, E.; Takahashi, Y.; Fukuyama, K.; Hodgson, K.O.; Hedman, B.; Solomon, E.I.; /Stanford U., Chem. Dept. /Georgia U. /Bologna U. /Osaka U. /SLAC, SSRL
2009-04-29
A persistent puzzle in the field of biological electron transfer is the conserved iron-sulfur cluster motif in both high potential iron-sulfur protein (HiPIP) and ferredoxin (Fd) active sites. Despite this structural similarity, HiPIPs react oxidatively at physiological potentials, whereas Fds are reduced. Sulfur K-edge x-ray absorption spectroscopy uncovers the substantial influence of hydration on this variation in reactivity. Fe-S covalency is much lower in natively hydrated Fd active sites than in HiPIPs but increases upon water removal; similarly, HiPIP covalency decreases when unfolding exposes an otherwise hydrophobically shielded active site to water. Studies on model compounds and accompanying density functional theory calculations support a correlation of Fe-S covalency with ease of oxidation and therefore suggest that hydration accounts for most of the difference between Fd and HiPIP reduction potentials.
14. Evolution of anatase surface active sites probed by in situ sum-frequency phonon spectroscopy.
Science.gov (United States)
Cao, Yue; Chen, Shiyou; Li, Yadong; Gao, Yi; Yang, Deheng; Shen, Yuen Ron; Liu, Wei-Tao
2016-09-01
Surface active sites of crystals often govern their relevant surface chemistry, yet to monitor them in situ in real atmosphere remains a challenge. Using surface-specific sum-frequency spectroscopy, we identified the surface phonon mode associated with the active sites of undercoordinated titanium ions and conjoint oxygen vacancies, and used it to monitor them on anatase (TiO2) (101) under ambient conditions. In conjunction with theory, we determined related surface structure around the active sites and tracked the evolution of oxygen vacancies under ultraviolet irradiation. We further found that unlike in vacuum, the surface oxygen vacancies, which dominate the surface reactivity, are strongly regulated by ambient gas molecules, including methanol and water, as well as weakly associated species, such as nitrogen and hydrogen. The result revealed a rich interplay between prevailing ambient species and surface reactivity, which can be omnipresent in environmental and catalytic applications of titanium dioxides.
15. Quantum delocalization of protons in the hydrogen bond network of an enzyme active site
CERN Document Server
Wang, Lu; Boxer, Steven G; Markland, Thomas E
2015-01-01
Enzymes utilize protein architectures to create highly specialized structural motifs that can greatly enhance the rates of complex chemical transformations. Here we use experiments, combined with ab initio simulations that exactly include nuclear quantum effects, to show that a triad of strongly hydrogen bonded tyrosine residues within the active site of the enzyme ketosteroid isomerase (KSI) facilitates quantum proton delocalization. This delocalization dramatically stabilizes the deprotonation of an active site tyrosine residue, resulting in a very large isotope effect on its acidity. When an intermediate analog is docked, it is incorporated into the hydrogen bond network, giving rise to extended quantum proton delocalization in the active site. These results shed light on the role of nuclear quantum effects in the hydrogen bond network that stabilizes the reactive intermediate of KSI, and the behavior of protons in biological systems containing strong hydrogen bonds.
16. Improving the neutral phytase activity from Bacillus amyloliquefaciens DSM 1061 by site-directed mutagenesis.
Science.gov (United States)
Xu, Wei; Shao, Rong; Wang, Zupeng; Yan, Xiuhua
2015-03-01
Neutral phytase is used as a feed additive for degradation of anti-nutritional phytate in aquatic feed industry. Site-directed mutagenesis of Bacillus amyloliquefaciens DSM 1061 phytase was performed with an aim to increase its activity. Mutation residues were chosen based on multiple sequence alignments and structure analysis of neutral phytsaes from different microorganisms. The mutation sites on surface (D148E, S197E and N156E) and around the active site (D52E) of phytase were selected. Analysis of the phytase variants showed that the specific activities of mutants D148E and S197E remarkably increased by about 35 and 13% over a temperature range of 40-75 °C at pH 7.0, respectively. The k cat of mutants D148E and S197E were 1.50 and 1.25 times than that of the wild-type phytase, respectively. Both D148E and S197E showed much higher thermostability than that of the wild-type phytase. However, mutants N156E and D52E led to significant loss of specific activity of the enzyme. Structural analysis revealed that these mutations may affect conformation of the active site of phytase. The present mutant phytases D148E and S197E with increased activities and thermostabilities have application potential as additives in aquaculture feed.
17. Stringency of the 2-His-1-Asp active-site motif in prolyl 4-hydroxylase.
Directory of Open Access Journals (Sweden)
Kelly L Gorres
Full Text Available The non-heme iron(II dioxygenase family of enzymes contain a common 2-His-1-carboxylate iron-binding motif. These enzymes catalyze a wide variety of oxidative reactions, such as the hydroxylation of aliphatic C-H bonds. Prolyl 4-hydroxylase (P4H is an alpha-ketoglutarate-dependent iron(II dioxygenase that catalyzes the post-translational hydroxylation of proline residues in protocollagen strands, stabilizing the ensuing triple helix. Human P4H residues His412, Asp414, and His483 have been identified as an iron-coordinating 2-His-1-carboxylate motif. Enzymes that catalyze oxidative halogenation do so by a mechanism similar to that of P4H. These halogenases retain the active-site histidine residues, but the carboxylate ligand is replaced with a halide ion. We replaced Asp414 of P4H with alanine (to mimic the active site of a halogenase and with glycine. These substitutions do not, however, convert P4H into a halogenase. Moreover, the hydroxylase activity of D414A P4H cannot be rescued with small molecules. In addition, rearranging the two His and one Asp residues in the active site eliminates hydroxylase activity. Our results demonstrate a high stringency for the iron-binding residues in the P4H active site. We conclude that P4H, which catalyzes an especially demanding chemical transformation, is recalcitrant to change.
18. Threatened and endangered wildlife species of the Hanford Site related to CERCLA characterization activities
Energy Technology Data Exchange (ETDEWEB)
Fitzner, R.E. [Pacific Northwest Lab., Richland, WA (United States); Weiss, S.G.; Stegen, J.A. [Westinghouse Hanford Co., Richland, WA (United States)
1994-06-01
The US Department of Energys (DOE) Hanford Site has been placed on the National Priorities List, which requires that it be remediated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) or Superfund. Potentially contaminated areas of the Hanford Site were grouped into operable units, and detailed characterization and investigation plans were formulated. The DOE Richland Operations Office requested Westinghouse Hanford Company (WHC) to conduct a biological assessment of the potential impact of these characterization activities on the threatened, endangered, and sensitive wildlife species of the Hanford Site. Additional direction for WHC compliances with wildlife protection can be found in the Environmental Compliance Manual. This document is intended to meet these requirements, in part, for the CERCLA characterization activities, as well as for other work comparable in scope. This report documents the biological assessment and describes the pertinent components of the Hanford Site as well as the planned characterization activities. Also provided are accounts of endangered, threatened, and federal candidate wildlife species on the Hanford Site and information as to how human disturbances can affect these species. Potential effects of the characterization activities are described with recommendations for mitigation measures.
19. Deletion of loop fragment adjacent to active site diminishes the stability and activity of exo-inulinase.
Science.gov (United States)
2016-11-01
Inulinases are classified as hydrolases and widely used in the food and medical industries. Here, we report the deletion of a six-membered adjacent active site loop fragment ((74)YGSDVT(79) sequence) from third Ω-loop of the exo-inulinase containing aspartate residue from Aspergillus niger to study its structural and functional importance. Site-directed mutagenesis was used to create the mutant of the exo-inulinase (Δ6SL). To investigate the stability of the region spanning this loop, MD simulations were performed 80ns for 20-85 residues. Molecular docking was performed to compare the interactions in the active sites of enzymes with fructose as a ligand. Accordingly, the functional thermostability of the exo-inulinase was significantly decreased upon loop fragment deletion. Evaluation of the kinetics parameters (Vmax, Km, kcat and, kcat/Km) and activation energy (Ea) of the catalysis of enzymes indicated the importance of the deleted sequence on the catalytic performance of the enzyme. In conclusion, six-membered adjacent active site loop fragment not only plays a crucial role in the stability of the enzyme, but also it involves in the enzyme catalysis through lowering the activation energy of the catalysis and effective improving the catalytic performance. Copyright © 2016. Published by Elsevier B.V.
20. Trace metal depositional patterns from an open pit mining activity as revealed by archived avian gizzard contents.
Science.gov (United States)
Bendell, L I
2011-02-15
Archived samples of blue grouse (Dendragapus obscurus) gizzard contents, inclusive of grit, collected yearly between 1959 and 1970 were analyzed for cadmium, lead, zinc, and copper content. Approximately halfway through the 12-year sampling period, an open-pit copper mine began activities, then ceased operations 2 years later. Thus the archived samples provided a unique opportunity to determine if avian gizzard contents, inclusive of grit, could reveal patterns in the anthropogenic deposition of trace metals associated with mining activities. Gizzard concentrations of cadmium and copper strongly coincided with the onset of opening and the closing of the pit mining activity. Gizzard zinc and lead demonstrated significant among year variation; however, maximum concentrations did not correlate to mining activity. The archived gizzard contents did provide a useful tool for documenting trends in metal depositional patterns related to an anthropogenic activity. Further, blue grouse ingesting grit particles during the time of active mining activity would have been exposed to toxicologically significant levels of cadmium. Gizzard lead concentrations were also of toxicological significance but not related to mining activity. This type of "pulse" toxic metal exposure as a consequence of open-pit mining activity would not necessarily have been revealed through a "snap-shot" of soil, plant or avian tissue trace metal analysis post-mining activity.
1. SABER: a computational method for identifying active sites for new reactions.
Science.gov (United States)
Nosrati, Geoffrey R; Houk, K N
2012-05-01
A software suite, SABER (Selection of Active/Binding sites for Enzyme Redesign), has been developed for the analysis of atomic geometries in protein structures, using a geometric hashing algorithm (Barker and Thornton, Bioinformatics 2003;19:1644-1649). SABER is used to explore the Protein Data Bank (PDB) to locate proteins with a specific 3D arrangement of catalytic groups to identify active sites that might be redesigned to catalyze new reactions. As a proof-of-principle test, SABER was used to identify enzymes that have the same catalytic group arrangement present in o-succinyl benzoate synthase (OSBS). Among the highest-scoring scaffolds identified by the SABER search for enzymes with the same catalytic group arrangement as OSBS were L-Ala D/L-Glu epimerase (AEE) and muconate lactonizing enzyme II (MLE), both of which have been redesigned to become effective OSBS catalysts, demonstrated by experiments. Next, we used SABER to search for naturally existing active sites in the PDB with catalytic groups similar to those present in the designed Kemp elimination enzyme KE07. From over 2000 geometric matches to the KE07 active site, SABER identified 23 matches that corresponded to residues from known active sites. The best of these matches, with a 0.28 Å catalytic atom RMSD to KE07, was then redesigned to be compatible with the Kemp elimination using RosettaDesign. We also used SABER to search for potential Kemp eliminases using a theozyme predicted to provide a greater rate acceleration than the active site of KE07, and used Rosetta to create a design based on the proteins identified.
2. The active site of low-temperature methane hydroxylation in iron-containing zeolites
Science.gov (United States)
Snyder, Benjamin E. R.; Vanelderen, Pieter; Bols, Max L.; Hallaert, Simon D.; Böttger, Lars H.; Ungur, Liviu; Pierloot, Kristine; Schoonheydt, Robert A.; Sels, Bert F.; Solomon, Edward I.
2016-08-01
An efficient catalytic process for converting methane into methanol could have far-reaching economic implications. Iron-containing zeolites (microporous aluminosilicate minerals) are noteworthy in this regard, having an outstanding ability to hydroxylate methane rapidly at room temperature to form methanol. Reactivity occurs at an extra-lattice active site called α-Fe(II), which is activated by nitrous oxide to form the reactive intermediate α-O; however, despite nearly three decades of research, the nature of the active site and the factors determining its exceptional reactivity are unclear. The main difficulty is that the reactive species—α-Fe(II) and α-O—are challenging to probe spectroscopically: data from bulk techniques such as X-ray absorption spectroscopy and magnetic susceptibility are complicated by contributions from inactive ‘spectator’ iron. Here we show that a site-selective spectroscopic method regularly used in bioinorganic chemistry can overcome this problem. Magnetic circular dichroism reveals α-Fe(II) to be a mononuclear, high-spin, square planar Fe(II) site, while the reactive intermediate, α-O, is a mononuclear, high-spin Fe(IV)=O species, whose exceptional reactivity derives from a constrained coordination geometry enforced by the zeolite lattice. These findings illustrate the value of our approach to exploring active sites in heterogeneous systems. The results also suggest that using matrix constraints to activate metal sites for function—producing what is known in the context of metalloenzymes as an ‘entatic’ state—might be a useful way to tune the activity of heterogeneous catalysts.
3. Gemvid, an open source, modular, automated activity recording system for rats using digital video
Directory of Open Access Journals (Sweden)
Leprince Pierre
2006-08-01
Full Text Available Abstract Background Measurement of locomotor activity is a valuable tool for analysing factors influencing behaviour and for investigating brain function. Several methods have been described in the literature for measuring the amount of animal movement but most are flawed or expensive. Here, we describe an open source, modular, low-cost, user-friendly, highly sensitive, non-invasive system that records all the movements of a rat in its cage. Methods Our activity monitoring system quantifies overall free movements of rodents without any markers, using a commercially available CCTV and a newly designed motion detection software developed on a GNU/Linux-operating computer. The operating principle is that the amount of overall movement of an object can be expressed by the difference in total area occupied by the object in two consecutive picture frames. The application is based on software modules that allow the system to be used in a high-throughput workflow. Documentation, example files, source code and binary files can be freely downloaded from the project website at http://bioinformatics.org/gemvid/. Results In a series of experiments with objects of pre-defined oscillation frequencies and movements, we documented the sensitivity, reproducibility and stability of our system. We also compared data obtained with our system and data obtained with an Actiwatch device. Finally, to validate the system, results obtained from the automated observation of 6 rats during 7 days in a regular light cycle are presented and are accompanied by a stability test. The validity of this system is further demonstrated through the observation of 2 rats in constant dark conditions that displayed the expected free running of their circadian rhythm. Conclusion The present study describes a system that relies on video frame differences to automatically quantify overall free movements of a rodent without any markers. It allows the monitoring of rats in their own
4. New active site oriented glyoxyl-agarose derivatives of Escherichia coli penicillin G acylase
Directory of Open Access Journals (Sweden)
Terreni Marco
2007-09-01
Full Text Available Abstract Background Immobilized Penicillin G Acylase (PGA derivatives are biocatalysts that are industrially used for the hydrolysis of Penicillin G by fermentation and for the kinetically controlled synthesis of semi-synthetic β-lactam antibiotics. One of the most used supports for immobilization is glyoxyl-activated agarose, which binds the protein by reacting through its superficial Lys residues. Since in E. coli PGA Lys are also present near the active site, an immobilization that occurs through these residues may negatively affect the performance of the biocatalyst due to the difficult diffusion of the substrate into the active site. A preferential orientation of the enzyme with the active site far from the support surface would be desirable to avoid this problem. Results Here we report how it is possible to induce a preferential orientation of the protein during the binding process on aldehyde activated supports. A superficial region of PGA, which is located on the opposite side of the active site, is enriched in its Lys content. The binding of the enzyme onto the support is consequently forced through the Lys rich region, thus leaving the active site fully accessible to the substrate. Different mutants with an increasing number of Lys have been designed and, when active, immobilized onto glyoxyl agarose. The synthetic performances of these new catalysts were compared with those of the immobilized wild-type (wt PGA. Our results show that, while the synthetic performance of the wt PGA sensitively decreases after immobilization, the Lys enriched mutants have similar performances to the free enzyme even after immobilization. We also report the observations made with other mutants which were unable to undergo a successful maturation process for the production of active enzymes or which resulted toxic for the host cell. Conclusion The desired orientation of immobilized PGA with the active site freely accessible can be obtained by increasing
5. Moving the Barricades to Physical Activity: A Qualitative Analysis of Open Streets Initiatives Across the United States.
Science.gov (United States)
Eyler, Amy A; Hipp, J Aaron; Lokuta, Julie
2015-01-01
Ciclovía, or Open Streets initiatives, are events where streets are opened for physical activity and closed to motorized traffic. Although the initiatives are gaining popularity in the United States, little is known about planning and implementing them. The goals of this paper are to explore the development and implementation of Open Streets initiatives and make recommendations for increasing the capacity of organizers to enhance initiative success. Phenomenology with qualitative analysis of structured interviews was used. Study setting was urban and suburban communities in the United States. Study participants were organizers of Open Streets initiatives in U.S. cities. Using a list of 47 events held in 2011, 27 lead organizers were interviewed by telephone about planning, implementation, and lessons learned. The interviews were digitally recorded and transcribed. A phenomenologic approach was used, an initial coding tool was developed after reviewing a sample of transcripts, and constant comparative coding methodology was applied. Themes and subthemes were generated from codes. The most common reasons for initiation were to highlight or improve health and transportation. Most initiatives aimed to reach the general population, but some targeted families, children, or specific neighborhoods. Getting people to understand the concept of Open Streets was an important challenge. Other challenges included lack of funding and personnel, and complex logistics. These initiatives democratize public space for citizens while promoting physical activity, social connectedness, and other broad agendas. There are opportunities for the research community to contribute to the expanse and sustainability of Open Streets, particularly in evaluation and dissemination.
6. Stereospecific Synthesis of 2-Iminothiazolidines via Domino Ring-Opening Cyclization of Activated Aziridines with Aryl- and Alkyl Isothiocyanates.
Science.gov (United States)
Bhattacharyya, Aditya; Kavitha, C V; Ghorai, Manas K
2016-08-05
Lewis acid catalyzed domino ring-opening cyclization of activated aziridines with aryl and alkyl isothiocyanates has been accomplished leading to the formation of a wide variety of highly substituted and functionalized 2-iminothiazolidines with excellent diastereo- and enantiospecificity (de, ee up to >99%). The reaction proceeds via a Lewis acid catalyzed SN2-type ring-opening of the activated aziridine followed by a concomitant 5-exo-dig cyclization in a domino fashion to furnish the 2-iminothiazolidine derivative in excellent yields (up to 99%).
7. Kv3 channel assembly, trafficking and activity are regulated by zinc through different binding sites.
Science.gov (United States)
Gu, Yuanzheng; Barry, Joshua; Gu, Chen
2013-05-15
Zinc, a divalent heavy metal ion and an essential mineral for life, regulates synaptic transmission and neuronal excitability via ion channels. However, its binding sites and regulatory mechanisms are poorly understood. Here, we report that Kv3 channel assembly, localization and activity are regulated by zinc through different binding sites. Local perfusion of zinc reversibly reduced spiking frequency of cultured neurons most likely by suppressing Kv3 channels. Indeed, zinc inhibited Kv3.1 channel activity and slowed activation kinetics, independent of its site in the N-terminal T1 domain. Biochemical assays surprisingly identified a novel zinc-binding site in the Kv3.1 C-terminus, critical for channel activity and axonal targeting, but not for the zinc inhibition. Finally, mutagenesis revealed an important role of the junction between the first transmembrane (TM) segment and the first extracellular loop in sensing zinc. Its mutant enabled fast spiking with relative resistance to the zinc inhibition. Therefore, our studies provide novel mechanistic insights into the multifaceted regulation of Kv3 channel activity and localization by divalent heavy metal ions.
8. Optimal Design for Open MR/Superconducting Magnet with Active Shielding
Institute of Scientific and Technical Information of China (English)
Chun-zhong WANG; Qiu-liang WANG; Lan-kai LI; Ming RONG; You-yuan ZHOU
2010-01-01
The optimal design method for an open Magnetic Resonance Imaging(MRI)superconducting magnet with an active shielding configuration is proposed Firstly,three pairs of current rings are employed as seed coils.By optimizing the homogeneity of Diameter Sphere Volume(DSV),the positions and currents of the seed coils will be obtained.Secondly,according to the positions and currents of the seed coils,the current density of superconducting wires is determined,and then the original sections for the coils can be achieved.An optimization for the homogeneity based on the constrained nonlinear optimization method is employed to determine the coils with homogeneity.Thirdly,the magnetic field generated by previous coils is set as the background field,then add two coils with reverse current,and optimize the stray field line of 5 Gauss in a certain scope.Finally,a further optimization for the homogeneity is used to get final coils.This method can also be used in the design of other axisymmettic superconducting MRI magnets.
9. Estimating drift of airborne pesticides during orchard spraying using active Open Path FTIR
Science.gov (United States)
Kira, Oz; Linker, Raphael; Dubowski, Yael
2016-10-01
The use of pesticides is important to ensure food security around the world. Unfortunately, exposure to pesticides is harmful to human health and the environment. This study suggests using active Open Path Fourier Transform Infra-Red (OP-FTIR) spectroscopy for monitoring and characterizing pesticide spray drift, which is one of the transfer mechanisms that lead to inhalation exposure to pesticides. Experiments were conducted in a research farm with two fungicides (Impulse and Bogiron), which were sprayed in the recommended concentration of ∼0.1%w in water, using a tractor-mounted air-assisted sprayer. The ability to detect and characterize the pesticide spray drift was tested in three types of environments: fallow field, young orchard, and mature orchard. During all spraying experiments the spectral signature of the organic phase of the pesticide solution was identified. Additionally, after estimating the droplets' size distribution using water sensitive papers, the OP-FTIR measurements enabled the estimation of the droplets load in the line of sight.
10. Target prediction for an open access set of compounds active against Mycobacterium tuberculosis.
Directory of Open Access Journals (Sweden)
Francisco Martínez-Jiménez
Full Text Available Mycobacterium tuberculosis, the causative agent of tuberculosis (TB, infects an estimated two billion people worldwide and is the leading cause of mortality due to infectious disease. The development of new anti-TB therapeutics is required, because of the emergence of multi-drug resistance strains as well as co-infection with other pathogens, especially HIV. Recently, the pharmaceutical company GlaxoSmithKline published the results of a high-throughput screen (HTS of their two million compound library for anti-mycobacterial phenotypes. The screen revealed 776 compounds with significant activity against the M. tuberculosis H37Rv strain, including a subset of 177 prioritized compounds with high potency and low in vitro cytotoxicity. The next major challenge is the identification of the target proteins. Here, we use a computational approach that integrates historical bioassay data, chemical properties and structural comparisons of selected compounds to propose their potential targets in M. tuberculosis. We predicted 139 target--compound links, providing a necessary basis for further studies to characterize the mode of action of these compounds. The results from our analysis, including the predicted structural models, are available to the wider scientific community in the open source mode, to encourage further development of novel TB therapeutics.
11. Antispasmodic activity of Symplocos paniculata is mediated through opening of ATP-dependent K+ channel
Directory of Open Access Journals (Sweden)
Khalid Hussain Janbaz
2016-06-01
Full Text Available Symplocos paniculata is a medicinal plant used by native healers to manage gastrointestinal ailments. The crude methanolic extract of S. paniculata was screened pharmacologically both in vitro and in vivo for the validation of its therapeutic potential. It suppressed the spontaneous activity of isolated rabbit jejunum preparations and also caused inhibition of the low K+ (20 mM- induced spastic contractions in isolated rabbit jejunum preparations in a manner comparable to cromakalim. The relaxant effect was found to be blocked following glibenclamide exposure of the isolated tissue preparations similar to cromakalim, suggesting that observed response was likely to be mediated through opening of ATP dependent K+ channels. Following oral administration to mice provided protection against castor oil-induced diarrhea in a manner similar to loperamide. The plant material was found safe in toxicity study up to oral dose of 8 g/kg in mice. Hence, present study provides a scientific basis for the vernacular use of S. paniculata in gastro-intestinal system.
12. Klammt open elastic activator and twin blocks in Class II malocclusion treatment.
Directory of Open Access Journals (Sweden)
Eduardo Maikel Curbeira Hernández
2009-04-01
Full Text Available Background: Klammt open elastic activator and twin blocks have been two of the most worldwide studied functional appliances; however, there are different opinions about their effect on the cranium-facial complex. Objective: To determine the efficacy of these appliances in the functional treatment in Class II division I syndrome in early mixed teething. Methods: Prospective, cuasi experimental, “before-after” study without control group, including all children between 6 and 9 years of Area II in Cienfuegos municipality. After applying inclusion criteria, 20 patients were selected through simple randomized sampling and distributed in two groups, one for each technique. Lateral cranium teleradiographies were taken at the beginning and after a year of treatment, and lineal and/or angular measurements of Steiner, Ricketts, McNamara and Legan Burstone cephalograms were applied. Results: Favourable changes in cranium lateral radiographies measurements were obtained mainly from therapy with twin blocks. There was a decrease in the angle formed by the joint planes nasion-point A and nasion-point B and facial convexity, increase in mandible length and inferior facial height. Nasolabial angle and labial protuberance didn´t increase significantly. Conclusions: treated patients positively modified their bio-typology, and growth trend showed positive variations during functional therapy.
13. Cytotoxic activity of a synthetic deoxypodophyllotoxin derivative with an opened D-ring.
Science.gov (United States)
Chen, Chuan; Wang, Cui-Cui; Wang, Zhong; Geng, Wen-Yue; Xu, Hui; Song, Xiao-Mei; Luo, Du-Qiang
2016-05-01
Podophyllotoxin and its synthetic derivatives are valuable medicinal agents that have antitumor, insecticidal, and antifungal properties. We previously synthesized a deoxypodophyllotoxin derivative with an opened D-ring (DPD) exhibiting potent insecticidal activity. This article was firstly performed to identify the cytotoxicity of DPD toward human cancer cell lines (SGC7901, HeLa, and A549) and normal cell line (HEK293T) using MTT assay. DPD showed potent cytotoxicity against human cancer lines (HeLa and A549) and less cytotoxicity against normal cell lines HEK293T. DPD could also induce the cell cycle arrest at G2/M phase in HeLa cells and significantly increase the phosphorylation (Tyr 15) of CDC2 leading to inactivation of CDC2. The effects of DPD on cellular microtubule networks were detected using immunofluorescence technique in HeLa cells. The immunofluorescence results showed DPD influenced the arrangement and organization of cellular microtubule networks in HeLa cells. Microtubules are long, hollow cylinders made up of polymerized tubulin dimers. Total microtubules were separated after DPD treatment. Western blot results showed that the free polymerized tubulin dimers were obviously increased after DPD treatment. DPD may be a good drug candidate with the therapeutic potential to human cancer by affecting microtubule polymerization.
14. Hydralazine-induced vasodilation involves opening of high conductance Ca2+-activated K+ channels
DEFF Research Database (Denmark)
Bang, Lone; Nielsen-Kudsk, J E; Gruhn, N
1998-01-01
The purpose of this study was to investigate whether high conductance Ca2+-activated K+ channels (BK(Ca)) are mediating the vasodilator action of hydralazine. In isolated porcine coronary arteries, hydralazine (1-300 microM), like the K+ channel opener levcromakalim, preferentially relaxed...... contractions induced by K+ (20 mM) compared with K+ (80 mM). In addition, concentration-relaxation curves for hydralazine (pD2 = 5.38 +/- 0.06; Emax = 85.9 +/- 3.6%) were shifted 10-fold to the right by the BK(Ca) blockers tetraethylammonium (1 mM) and iberiotoxin (0.1 microM). In contrast, nimodipine (a Ca2......+-entry blocker), relaxed contractions induced by K+ (20 mM) and K+ (80 mM) equally and nimodipine-induced relaxations were neither antagonized by tetraethylammonium nor by iberiotoxin. In isolated perfused rat hearts, hydralazine (1 microM) increased coronary flow by 28.8 +/- 2.7%. Iberiotoxin (0.1 micro...
15. The ryanodine receptor pore blocker neomycin also inhibits channel activity via a previously undescribed high-affinity Ca(2+) binding site.
Science.gov (United States)
Laver, Derek R; Hamada, Tomoyo; Fessenden, James D; Ikemoto, Noriaki
2007-12-01
In this study, we present evidence for the mechanism of neomycin inhibition of skeletal ryanodine receptors (RyRs). In single-channel recordings, neomycin produced monophasic inhibition of RyR open probability and biphasic inhibition of [(3)H]ryanodine binding. The half-maximal inhibitory concentration (IC(50)) for channel blockade by neomycin was dependent on membrane potential and cytoplasmic [Ca(2+)], suggesting that neomycin acts both as a pore plug and as a competitive antagonist at a cytoplasmic Ca(2+) binding site that causes allosteric inhibition. This novel Ca(2+)/neomycin binding site had a neomycin affinity of 100 nM: and a Ca(2+) affinity of 35 nM,: which is 30-fold higher than that of the well-described cytoplasmic Ca(2+) activation site. Therefore, a new high-affinity class of Ca(2+) binding site(s) on the RyR exists that mediates neomycin inhibition. Neomycin plugging of the channel pore induced brief (1-2 ms) conductance substates at 30% of the fully open conductance, whereas allosteric inhibition caused complete channel closure with durations that depended on the neomycin concentration. We quantitatively account for these results using a dual inhibition model for neomycin that incorporates voltage-dependent pore plugging and Ca(2+)-dependent allosteric inhibition.
16. The role of hydrophobic active-site residues in substrate specificity and acyl transfer activity of penicillin acylase
NARCIS (Netherlands)
Alkema, WBL; Dijkhuis, AJ; de Vries, E; Janssen, DB
2002-01-01
Penicillin acylase of Escherichia colt catalyses the hydrolysis and synthesis of beta-lactam antibiotics. To study the role of hydrophobic residues in these reactions, we have mutated three active-site phenylalanines. Mutation of alphaF146, betaF24 and betaF57 to Tyr, Trp, Ala or Leu yielded mutants
17. Active catalytic sites in the ammoxidation of propane and propene over V-Sb-O catalysts
Energy Technology Data Exchange (ETDEWEB)
Buchholz, S.A.; Zanthoff, H.W. [Bochum Univ. (Germany). Lehrstuhl fuer Technische Chemie
1998-12-31
The ammoxidation of propane over VSb{sub y}O{sub x} catalysts (y=1, 2, 5) was investigated with respect to the role of different oxygen species in the selective and non selective reaction steps using transient experiments in the Temporal Analysis of Products (TAP) reactor. Only lattice oxygen is involved in the oxidation reactions. Using isotopic labelled oxygen it is shown that two different active sites exist on the surface. On site A, which can be reoxidized faster by gas phase oxygen compared to site B, mainly CO is formed. On site B CO{sub 2} and acrolein as well as NO and N{sub 2}O in the presence of ammonia in the feed gas are formed and reoxidation mainly occurs with bulk lattice oxygen. (orig.)
18. Open hardware for open science
CERN Multimedia
CERN Bulletin
2011-01-01
Inspired by the open source software movement, the Open Hardware Repository was created to enable hardware developers to share the results of their R&D activities. The recently published CERN Open Hardware Licence offers the legal framework to support this knowledge and technology exchange. Two years ago, a group of electronics designers led by Javier Serrano, a CERN engineer, working in experimental physics laboratories created the Open Hardware Repository (OHR). This project was initiated in order to facilitate the exchange of hardware designs across the community in line with the ideals of “open science”. The main objectives include avoiding duplication of effort by sharing results across different teams that might be working on the same need. “For hardware developers, the advantages of open hardware are numerous. For example, it is a great learning tool for technologies some developers would not otherwise master, and it avoids unnecessary work if someone ha...
19. Researching Resistance to Open Education Resource Contribution: An Activity Theory Approach
Science.gov (United States)
Cox, Glenda
2013-01-01
Higher education and associated institutions are beginning to share teaching materials known as Open Educational Resources (OER) or open courseware across the globe. Their success depends largely on the willingness of academics at these institutions to add their teaching resources. In a survey of the literature on OER there are several articles…
20. Final closure plan for the high-explosives open burn treatment facility at Lawrence Livermore National Laboratory Experimental Test Site 300
Energy Technology Data Exchange (ETDEWEB)
Mathews, S.
1997-04-01
This document addresses the interim status closure of the HE Open Bum Treatment Facility, as detailed by Title 22, Division 4.5, Chapter 15, Article 7 of the Califonia Code of Regulations (CCR) and by Title 40, Code of Federal Regulations (CFR) Part 265, Subpart G, Closure and Post Closure. The Closure Plan (Chapter 1) and the Post- Closure Plan (Chapter 2) address the concept of long-term hazard elimination. The Closure Plan provides for capping and grading the HE Open Bum Treatment Facility and revegetating the immediate area in accordance with applicable requirements. The Closure Plan also reflects careful consideration of site location and topography, geologic and hydrologic factors, climate, cover characteristics, type and amount of wastes, and the potential for contaminant migration. The Post-Closure Plan is designed to allow LLNL to monitor the movement, if any, of pollutants from the treatment area. In addition, quarterly inspections will ensure that all surfaces of the closed facility, including the cover and diversion ditches, remain in good repair, thus precluding the potential for contaminant migration.
1. Active site diversification of P450cam with indole generates catalysts for benzylic oxidation reactions.
Science.gov (United States)
Kelly, Paul P; Eichler, Anja; Herter, Susanne; Kranz, David C; Turner, Nicholas J; Flitsch, Sabine L
2015-01-01
Cytochrome P450 monooxygenases are useful biocatalysts for C-H activation, and there is a need to expand the range of these enzymes beyond what is naturally available. A panel of 93 variants of active self-sufficient P450cam[Tyr96Phe]-RhFRed fusion enzymes with a broad diversity in active site amino acids was developed by screening a large mutant library of 16,500 clones using a simple, highly sensitive colony-based colorimetric screen against indole. These mutants showed distinct fingerprints of activity not only when screened in oxidations of substituted indoles but also for unrelated oxidations such as benzylic hydroxylations.
2. Active site diversification of P450cam with indole generates catalysts for benzylic oxidation reactions
Directory of Open Access Journals (Sweden)
Paul P. Kelly
2015-09-01
Full Text Available Cytochrome P450 monooxygenases are useful biocatalysts for C–H activation, and there is a need to expand the range of these enzymes beyond what is naturally available. A panel of 93 variants of active self-sufficient P450cam[Tyr96Phe]-RhFRed fusion enzymes with a broad diversity in active site amino acids was developed by screening a large mutant library of 16,500 clones using a simple, highly sensitive colony-based colorimetric screen against indole. These mutants showed distinct fingerprints of activity not only when screened in oxidations of substituted indoles but also for unrelated oxidations such as benzylic hydroxylations.
3. POISONING OF ACTIVE SITES ON ZIEGLER-NATTA CATALYST FOR PROPYLENE POLYMERIZATION
Institute of Scientific and Technical Information of China (English)
Kitti Tangjituabun; Sang Yull Kim; Yuichi Hiraoka; Toshiaki Taniike; Minoru Terano; Bunjerd Jongsomjit; Piyasan Praserthdam
2008-01-01
The effects of poisoning materials on catalytic activity and isospecificity of the supported Ziegler-Natta catalyst were investigated.A minor amount of simple structure of Lewis base,i.e.,methanol,acetone,ethyl acetate,was introduced into the catalyst slurry for partial poisoning catalytic active centers.It was found that the variations in deactivation power were in the order of methanol＞acetone＞ethyl acetate.The kinetic investigation via stopped-flow polymerization showed that poisoning compounds caused a decrease in activity through the reduction of the number of active sites whereas no effect on the degree of isotacticity was observed.
4. Low temperature syntheses and reactivity of Cu2O2 active-site models.
Science.gov (United States)
Citek, Cooper; Herres-Pawlis, Sonja; Stack, T Daniel P
2015-08-18
Nature's facility with dioxygen outmatches modern chemistry in the oxidation and oxygenation of materials and substrates for biosynthesis and cellular metabolism. The Earth's most abundant naturally occurring oxidant is-frankly-poorly understood and controlled, and thus underused. Copper-based enzyme metallocofactors are ubiquitous to the efficient consumption of dioxygen by all domains of life. Over the last several decades, we have joined many research groups in the study of copper- and dioxygen-dependent enzymes through close investigation of synthetically derived, small-molecule active-site analogs. Simple copper-dioxygen clusters bearing structural and spectroscopic similarity to dioxygen-activating enzymes can be probed for their fundamental geometrical, electronic, and reactive properties using the tools available to inorganic and synthetic chemistry. Our exploration of the copper-dioxygen arena has sustained product evaluation of the key dynamics and reactivity of binuclear Cu2O2 compounds. Almost exclusively operating at low temperatures, from -78 °C to solution characterization even at -125 °C, we have identified numerous compounds supported by simple and easily accessed, low molecular weight ligands-chiefly families of bidentate diamine chelates. We have found that by stripping away complexity in comparison to extended protein tertiary structures or sophisticated, multinucleating architectures, we can experimentally manipulate activated compounds and open pathways of reactivity toward exogenous substrates that both inform on and extend fundamental mechanisms of oxygenase enzymes. Our recent successes have advanced understanding of the tyrosinase enzyme, and related hemocyanin and NspF, and the copper membrane monooxygenases, specifically particulate methane monooxygenase (pMMO) and ammonia monooxygenase (AMO). Tyrosinase, ubiquitously distributed throughout life, is fundamental to the copper-based oxidation of phenols and the production of chromophores
5. Identification of an Allosteric Binding Site on Human Lysosomal Alpha-Galactosidase Opens the Way to New Pharmacological Chaperones for Fabry Disease
Science.gov (United States)
den-Haan, Helena; Pérez-Sánchez, Horacio; Del Prete, Rosita; Liguori, Ludovica; Cimmaruta, Chiara; Lukas, Jan; Andreotti, Giuseppina
2016-01-01
Personalized therapies are required for Fabry disease due to its large phenotypic spectrum and numerous different genotypes. In principle, missense mutations that do not affect the active site could be rescued with pharmacological chaperones. At present pharmacological chaperones for Fabry disease bind the active site and couple a stabilizing effect, which is required, to an inhibitory effect, which is deleterious. By in silico docking we identified an allosteric hot-spot for ligand binding where a drug-like compound, 2,6-dithiopurine, binds preferentially. 2,6-dithiopurine stabilizes lysosomal alpha-galactosidase in vitro and rescues a mutant that is not responsive to a mono-therapy with previously described pharmacological chaperones, 1-deoxygalactonojirimycin and galactose in a cell based assay. PMID:27788225
6. Autocatalytic activation of the furin zymogen requires removal of the emerging enzyme's N-terminus from the active site.
Directory of Open Access Journals (Sweden)
Katarzyna Gawlik
Full Text Available Before furin can act on protein substrates, it must go through an ordered process of activation. Similar to many other proteinases, furin is synthesized as a zymogen (profurin which becomes active only after the autocatalytic removal of its auto-inhibitory prodomain. We hypothesized that to activate profurin its prodomain had to be removed and, in addition, the emerging enzyme's N-terminus had to be ejected from the catalytic cleft.We constructed and analyzed the profurin mutants in which the egress of the emerging enzyme's N-terminus from the catalytic cleft was restricted. Mutants were autocatalytically processed at only the primary cleavage site Arg-Thr-Lys-Arg(107 downward arrowAsp(108, but not at both the primary and the secondary (Arg-Gly-Val-Thr-Lys-Arg(75 downward arrowSer(76 cleavage sites, yielding, as a result, the full-length prodomain and mature furins commencing from the N-terminal Asp108. These correctly processed furin mutants, however, remained self-inhibited by the constrained N-terminal sequence which continuously occupied the S' sub-sites of the catalytic cleft and interfered with the functional activity. Further, using the in vitro cleavage of the purified prodomain and the analyses of colon carcinoma LoVo cells with the reconstituted expression of the wild-type and mutant furins, we demonstrated that a three-step autocatalytic processing including the cleavage of the prodomain at the previously unidentified Arg-Leu-Gln-Arg(89 downward arrowGlu(90 site, is required for the efficient activation of furin.Collectively, our results show the restrictive role of the enzyme's N-terminal region in the autocatalytic activation mechanisms. In a conceptual form, our data apply not only to profurin alone but also to a range of self-activated proteinases.
7. Study on the active sites of Cu-ZSM-5 in trichloroethylene catalytic combustion with air
Institute of Scientific and Technical Information of China (English)
Cheng Hua Xu; Chuan Qi Liu; Yan Zhong; Xiu Zhou Yang; Jian Ying Liu; Ying Chun Yang; Zhi Xiang Ye
2008-01-01
The catalytic activity of Cu-ZSM-5 in trichloroethylene (TCE) combustion increases with the increasing skeletal Cu amount and however decreases with the increase of surface amorphous CuO,which is detected by infrared spectroscopy (IR) and diffuse reflectance ultraviolet-visible spectroscopy (DRS-UV-vis),therefore the skeletal Cu species are concluded to be the active sites for the TCE combustion.
8. Thiolactomycin inhibits D-aspartate oxidase: a novel approach to probing the active site environment.
Science.gov (United States)
Katane, Masumi; Saitoh, Yasuaki; Hanai, Toshihiko; Sekine, Masae; Furuchi, Takemitsu; Koyama, Nobuhiro; Nakagome, Izumi; Tomoda, Hiroshi; Hirono, Shuichi; Homma, Hiroshi
2010-10-01
D-Aspartate oxidase (DDO) and D-amino acid oxidase (DAO) are flavin adenine dinucleotide (FAD)-containing flavoproteins that catalyze the oxidative deamination of D-amino acids. While several functionally and structurally important amino acid residues have been identified in the DAO protein, little is known about the structure-function relationships of DDO. In the search for a potent DDO inhibitor as a novel tool for investigating its structure-function relationships, a large number of biologically active compounds of microbial origin were screened for their ability to inhibit the enzymatic activity of mouse DDO. We discovered several compounds that inhibited the activity of mouse DDO, and one of the compounds identified, thiolactomycin (TLM), was then characterized and evaluated as a novel DDO inhibitor. TLM reversibly inhibited the activity of mouse DDO with a mixed type of inhibition more efficiently than meso-tartrate and malonate, known competitive inhibitors of mammalian DDOs. The selectivity of TLM was investigated using various DDOs and DAOs, and it was found that TLM inhibits not only DDO, but also DAO. Further experiments with apoenzymes of DDO and DAO revealed that TLM is most likely to inhibit the activities of DDO and DAO by competition with both the substrate and the coenzyme, FAD. Structural models of mouse DDO/TLM complexes supported this finding. The binding mode of TLM to DDO was validated further by site-directed mutagenesis of an active site residue, Arg-237. Collectively, our findings show that TLM is a novel, active site-directed DDO inhibitor that will be useful for elucidating the molecular details of the active site environment of DDO. Copyright © 2010 Elsevier Masson SAS. All rights reserved.
9. Screening Approach to the Activation of Soil and Contamination of Groundwater at Linear Proton Accelerator Sites
CERN Document Server
Otto, Thomas
The activation of soil and the contamination of groundwater at proton accelerator sites with the radionuclides 3H and 22Na are estimated with a Monte-Carlo calculation and a conservative soil- and ground water model. The obtained radionuclide concentrations show that the underground environment of future accelerators must be adequately protected against a migration of activation products. This study is of particular importance for the proton driver accelerator in the planned EURISOL facility.
10. Active layer dynamics in three sites with contrasted topography in the Byers Peninsula (Livingston Island, Antarctica)
Science.gov (United States)
Oliva, Marc; Ruiz-Fernández, Jesús; Vieira, Gonçalo
2015-04-01
Topography exerts a key role on permafrost distribution in areas where mean annual temperatures are slightly negative. This is the case of low-altitude environments in Maritime Antarctica, namely in the South Shetland Islands, where permafrost is marginal to discontinuous until elevations of 20-40 m asl turning to continuous at higher areas. Consequently, the active layer dynamics is also strongly conditioned by the geomorphological setting. In January 2014 we installed three sites for monitoring the active layer dynamics across the Byers Peninsula (Livingston Island, South Shetland Islands) in different geomorphological environments at elevations between 60 and 100 m. The purpose was to examine the role of the topography and microclimatic conditions on the active layer dynamics. At each site a set of loggers was set up to monitor: air temperatures, snow thickness, ground temperatures until 80 cm together with the coupling atmosphere-ground temperatures. During the first year of monitoring the mean annual air temperatures show similar values in the three sites, in all cases slightly below freezing. The snowy conditions during this year in this archipelago have resulted in a late melting of snow, which has also conditioned the duration of frozen conditions in the uppermost soil layers. Topography has a strong influence on snow cover duration, which in turn affects frozen ground conditions. The Domo site is located in a higher position with respect to the central plateau of Byers; here, the wind is stronger and snow cover thinner, which has conditioned a longer thawing season than in the other two sites (Cerro Negro, Escondido). These two sites are located in topographically protected areas favouring snow accumulation. The longer persistence of snow conditions a longer duration of negative temperatures in the active layer of the permafrost. This research was financially supported by the HOLOANTAR project (Portuguese Science Foundation) and the AXA Research Fund.
11. Spectroscopic studies on the active site of hydroperoxide lyase : the influence of detergents on its conformation
NARCIS (Netherlands)
Vliegenthart, J.F.G.; Noordermeer, M.A.; Veldink, G.A.
2001-01-01
Expression of high quantities of alfalfa hydroperoxide lyase in Escherichia coli made it possible to study its active site and structure in more detail. Circular dichroism (CD) spectra showed that hydroperoxide lyase consists for about 75% of alpha-helices. Electron paramagnetic resonance (EPR) spec
12. Creation of a putative third metal binding site in type II dihydroorotases significantly enhances enzyme activity.
Science.gov (United States)
Huang, Yen-Hua; Huang, Cheng-Yang
2015-01-01
Dihydroorotase (DHOase) is the third enzyme in the de novo biosynthesis pathway of pyrimidine nucleotides. DHOase is divided into two types (I and II). Type II DHOase generally contains a binuclear metal center in its active site. Recently, the crystal structure of DHOase domain in human CAD protein (huDHOase) has revealed three metal ions in the protein's active site. However, whether type II DHOase can have the critical third metal ion, as observed in huDHOase, remains unknown. In the present study, the putative third metal binding site in type II enzymes, such as the prokaryotic Salmonella enterica serovar Typhimurium LT2 DHOase (StDHOase) and the eukaryotic Saccharomyces cerevisiae DHOase (ScDHOase), was created and identified. StDHOase T198E and ScDHOase T208E mutants had higher activities compared with their wild-type enzymes. The need for a higher DHOase stability and activity may drive creation of the third metal ion binding site in huDHOase, which can be achieved by mutating a highly conserved position T in type II dihydroorotases to E, similar to that in huDHOase.
13. 78 FR 8190 - Commercial Wind Leasing and Site Assessment Activities on the Atlantic Outer Continental Shelf...
Science.gov (United States)
2013-02-05
... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Commercial Wind Leasing and Site Assessment Activities on the Atlantic... Notice of Intent to Prepare an Environmental Assessment (EA) for Commercial Wind Leasing and...
14. 77 FR 74218 - Commercial Wind Leasing and Site Assessment Activities on the Atlantic Outer Continental Shelf...
Science.gov (United States)
2012-12-13
... Bureau of Ocean Energy Management Commercial Wind Leasing and Site Assessment Activities on the Atlantic... suitable for wind energy leasing on the OCS, known as Wind Energy Areas (WEAs) and to obtain public and... these areas to achieve an efficient and responsible renewable energy leasing process. More...
15. Aberration-corrected imaging of active sites on industrial catalyst nanoparticles
DEFF Research Database (Denmark)
Gontard, Lionel Cervera; Chang, L-Y; Hetherington, CJD
2007-01-01
Picture perfect: Information about the local topologies of active sites on commercial nanoparticles can be gained with atomic resolution through spherical-aberration-corrected transmission electron microscopy (TEM). A powder of Pt nanoparticles on carbon black was examined with two advanced TEM t...
16. Active-site residues of procarboxypeptidase Y are accessible to chemical modification
DEFF Research Database (Denmark)
Sørensen, S O; Winther, Jakob R.
1994-01-01
The accessibility of the active-site cleft of procarboxypeptidase Y from Saccharomyces cerevisiae has been studied by chemical modifications of two specific amino-acid residues. Previous studies have shown that these residues, Cys-341 and Met-398 in the mature enzyme, are located in the S1 and S'1...
17. Aberration-corrected imaging of active sites on industrial catalyst nanoparticles
DEFF Research Database (Denmark)
Gontard, Lionel Cervera; Chang, L-Y; Hetherington, CJD;
2007-01-01
Picture perfect: Information about the local topologies of active sites on commercial nanoparticles can be gained with atomic resolution through spherical-aberration-corrected transmission electron microscopy (TEM). A powder of Pt nanoparticles on carbon black was examined with two advanced TEM t...
18. Artificial Metalloenzymes for Asymmetric Catalysis by Creation of Novel Active Sites in Protein and DNA Scaffolds
NARCIS (Netherlands)
Drienovska, Ivana; Roelfes, Gerard
2015-01-01
Artificial metalloenzymes have emerged as a promising new approach to asymmetric catalysis. In our group, we are exploring novel artificial metalloenzyme designs involving creation of a new active site in a protein or DNA scaffold that does not have an existing binding pocket. In this review, we giv
19. Molecular Interactions Between the Active Sites of RGD (Arg-Gly-Asp with its Receptor (Integrine
Directory of Open Access Journals (Sweden)
E. Jauregui
2000-03-01
Full Text Available A study of the molecular interactions between the active sites of RGD (Arg-Gly-Asp with it Receptor using simultaions is reported. Our calculations indicate that the guanidine-carboxylate complex is energetically favourd with respect to the guanidine-methyl tetrazole complex.
20. Domestic activities at the Linear Pottery site of Elsloo (Netherlands) : a look from under the microscoop
NARCIS (Netherlands)
Gijn, van A.L.; Mazzucco, N.; Hamon, C.; Allard, P.; Ilett, M.
2013-01-01
Use-wear analysis of a sample of flint tools from the site of Elsloo, situated in the Graetheide cluster (NL), has shed light on the domestic activities carried out within the settlement. It was shown that hide processing predominates. The extent and character of the wear on the hide working impleme
1. Site-directed mutagenesis of the Anabaena sp. strain PCC 7120 nitrogenase active site to increase photobiological hydrogen production.
Science.gov (United States)
Masukawa, Hajime; Inoue, Kazuhito; Sakurai, Hidehiro; Wolk, C Peter; Hausinger, Robert P
2010-10-01
Cyanobacteria use sunlight and water to produce hydrogen gas (H₂), which is potentially useful as a clean and renewable biofuel. Photobiological H₂ arises primarily as an inevitable by-product of N₂ fixation by nitrogenase, an oxygen-labile enzyme typically containing an iron-molybdenum cofactor (FeMo-co) active site. In Anabaena sp. strain 7120, the enzyme is localized to the microaerobic environment of heterocysts, a highly differentiated subset of the filamentous cells. In an effort to increase H₂ production by this strain, six nitrogenase amino acid residues predicted to reside within 5 Å of the FeMo-co were mutated in an attempt to direct electron flow selectively toward proton reduction in the presence of N₂. Most of the 49 variants examined were deficient in N₂-fixing growth and exhibited decreases in their in vivo rates of acetylene reduction. Of greater interest, several variants examined under an N₂ atmosphere significantly increased their in vivo rates of H₂ production, approximating rates equivalent to those under an Ar atmosphere, and accumulated high levels of H₂ compared to the reference strains. These results demonstrate the feasibility of engineering cyanobacterial strains for enhanced photobiological production of H₂ in an aerobic, nitrogen-containing environment.
2. A facile reflux procedure to increase active surface sites form highly active and durable supported palladium@platinum bimetallic nanodendrites
Science.gov (United States)
Wang, Qin; Li, Yingjun; Liu, Baocang; Xu, Guangran; Zhang, Geng; Zhao, Qi; Zhang, Jun
2015-11-01
A series of well-dispersed bimetallic Pd@Pt nanodendrites uniformly supported on XC-72 carbon black are fabricated by using different capping agents. These capping agents are essential for the branched morphology control. However, the surfactant adsorbed on the nanodendrites surface blocks the access of reactant molecules to the active surface sites, and the catalytic activities of these bimetallic nanodendrites are significantly restricted. Herein, a facile reflux procedure to effectively remove the capping agent molecules without significantly affecting their sizes is reported for activating supported nanocatalysts. More significantly, the structure and morphology of the nanodendrites can also be retained, enhancing the numbers of active surface sites, catalytic activity and stability toward methanol and ethanol electro-oxidation reactions. The as-obtained hot water reflux-treated Pd@Pt/C catalyst manifests superior catalytic activity and stability both in terms of surface and mass specific activities, as compared to the untreated catalysts and the commercial Pt/C and Pd/C catalysts. We anticipate that this effective and facile removal method has more general applicability to highly active nanocatalysts prepared with various surfactants, and should lead to improvements in environmental protection and energy production.
3. Site-specific profiles of estrogenic activity in agricultural areas of California's inland waters.
Science.gov (United States)
Lavado, Ramon; Loyo-Rosales, Jorge E; Floyd, Emily; Kolodziej, Edward P; Snyder, Shane A; Sedlak, David L; Schlenk, Daniel
2009-12-15
To evaluate the occurrence and sources of compounds capable of feminizing fish in agriculturally impacted waterways of the Central Valley of California, water samples were extracted and subjected to chemical analyses as well as in vitro and in vivo measurements of vitellogenin in juvenile rainbow trout (Oncorhynchus mykiss). Among the 16 sites sampled, 6 locations frequently exhibited elevated concentrations of estrogenic substances with 17beta-estradiol equivalents up to 242 ng/L in vitro and 12 microg/kg in vivo. The patterns of activity varied among sites, with two sites showing elevated activity only in vitro, two showing elevated activity only in vivo, and two showing elevated activity in both assays. Sequential elution of solid-phase extraction (SPE) disks followed by bioassay-guided fractionation was used to characterize water samples from the two locations where activity was observed in both bioassays. The highest estrogenic activity was observed in the most nonpolar fractions (80-100% methanol eluent) from the Napa River, while most of the activity in the Sacramento River Delta eluted in the 60% methanol eluent. Quantitative analyses of SPE extracts and additional HPLC fractionation of the SPE extracts by GC-MS/MS and LC-MS/MS indicated concentrations of steroid hormones, alkylphenol polyethoxylates, and herbicides that were at least 1-3 orders of magnitude below bioassay 17beta-estradiol equivalent calculations. Given the different patterns of activity and chemical properties of the estrogenic compounds, it appears that estrogenic activity in these agriculturally impacted surface waters is attributable to multiple compounds. Further investigation is needed to identify the compounds causing the estrogenic activity and to determine the potential impacts of these compounds on feral fish.
4. The role of the catalysts with highly dispersed and isolated active sites in the selective oxidation of light hydrocarbons
Institute of Scientific and Technical Information of China (English)
WANG Hongxuan; ZHAO Zhen
2005-01-01
This review summarizes the role of catalysts with highly dispersed and isolated active sites (active sites: supported atoms f≤0.5 % ) in the selective oxidation of light hydrocarbons, such as methane, ethane and propane, into oxygenatesand the epoxidation of olefins. The plausible structures of the highly dispersed and isolated active species, as well as their effects on the catalytic performances are discussed. The special physico-chemical properties and the functional mechanism of the catalysts with highly dispersed and isolated active sites, as well as the preparation, characterization of the catalysts with highly dispersed and isolated active sites and their applications in other types of reactions of lower hydrocarbons are summarized.
5. Geologic Maps and Cross Sections of the Tuba City Open Dump Site and Vicinity, With Implications for the Occurrence and Flow of Ground Water
Science.gov (United States)
Otton, James K.; Johnson, Ray H.; Horton, Robert J.
2008-01-01
This report is designed to make available to interested parties geologic and limited hydrologic and geochemical information about the Tuba City Open Dump (TCOD) site. This information has been gathered during studies of the site from January to September 2008. Mapping by the authors and construction of cross sections show that a section of gently northeast-dipping Jurassic sedimentary rocks underlies the TCOD and vicinity. Low mesas in the area are capped by variably cemented gravels and siliceous limestones. Surficial sediments are composed of eolian sand and fluvially reworked eolian sand that overlie bedrock underneath the TCOD. Nearby Pasture Canyon is underlain by fluvial and floodplain sediment consisting of sand and silt. Shallow ground water of the water-table aquifer at the TCOD moves westward through the surficial sediment and the underlying weathered bedrock to Pasture Canyon then southward along the canyon. A fracture zone extends up the wash that passes just to the north of the TCOD and brings deeper ground water of the N-aquifer to the water-table aquifer. Bedrock consists of the Jurassic Navajo Sandstone composed of thick sections of eolian crossbedded sandstone with lesser laterally discontinuous layers of silty sandstone, siltstone, and limestone. Below the Navajo Sandstone is a section informally known as the Kayenta Formation-Navajo Sandstone transition zone. It is composed of calcareous sandstone, silty sandstone, siltstone, and limestone beds that intertongue with crossbedded sandstone. The finer grained rocks in both major bedrock units form aquitards that limit downward movement of ground water. The water-table aquifer is perched on these aquitards, which locally occurs beneath the two open dumps that form the TCOD site. A monocline occupies the position of Pasture Canyon west of the TCOD. Fractures likely related to the monocline are exposed in several localities. Deep ground waters consist of dilute calcium-bicarbonate waters low in all
6. [Effects of nootropic agents on visual functions and lacrimal antioxidative activity in patients with primary open-angle glaucoma].
Science.gov (United States)
Davydova, N G; Kuznetsova, T P; Borisova, S A; Abdulkadyrova, M Zh
2006-01-01
The paper presents the results of an investigation of the effect of the nootropic agents pantogam and nooclerine on visual functions in patients with primary open-angle glaucoma. These agents have been found to have a beneficial effect on the functional activity of the retina and optic nerve, light sensitivity, hemo- and hydrodynamics of the eye.
7. Rehabilitating a landfill site of lowland tropical landscape into an urban green space: A case study from the Open University of Sri Lanka
Directory of Open Access Journals (Sweden)
2016-12-01
Full Text Available This study examines vegetation, carbon sequestration, and spatial and temporal changes of green space at the premises of the Open University of Sri Lanka (OUSL. The primary objective of this study is to examine floral diversity of the OUSL premises that was rehabilitated from a landfill site and to determine suitable trees for landfill sites based on growth performance and biomass carbon stocks. The girth and height of plants ⩾5 cm dbh were measured to estimate biomass carbon stocks of each individual tree. GPS coordinates of each individual tree were taken for spatial mapping. Urban green spaces were extracted from Satellite view of Google Earth for a decade using screen digitizing techniques. A total of 722 individuals, comprising 95 plant species belonging to 75 genera and 33 families, were recorded. Of the total species 45% were native species. The above-ground and below-ground biomass were estimated to be 50 (t C/ha and 10 (t C/ha respectively. These results are comparable with above-ground biomass and below-ground biomass in the dry zone forest (60 and 17 (t C/ha respectively. The study recognized that Terminalia catappa, Filicium decipiens, Mangifera indica, Cassia bacillaris and Tabebuia rosea species grow well in such landfill with effective carbon accumulation, and the species list presented in this paper will provide useful information that will help city planners to maximize biomass carbon sequestration by choosing optimal plants for landscaping in landfill sites.
8. Structure and Function Relationship of Activated Retinal Glia in Primary Open-Angle Glaucoma Patients
Directory of Open Access Journals (Sweden)
Christoph Nützi
2017-01-01
Full Text Available Purpose. To evaluate clinically activated retinal astrocytes and Müller cells (ARAM regarding retinal sensitivity and retinal nerve fiber layer (RNFL thickness in primary open-angle glaucoma (POAG. Methods. Central visual field (VF; i.e., retinal sensitivity was measured with a custom-made macular pattern by microperimetry and correlated with the presence (ARAM+ or absence (ARAM− of ARAM on red-free fundus photography and with the corresponding RNFL by optical coherence tomography (OCT. Results. In the eyes of POAG patients, ARAM+ had overall a significantly lower retinal sensitivity (ARAM+: 7.34 dB, ARAM−: 11.9 dB; p<0.001 and lower RNFL thickness in the inferior peripapillary quadrants compared to ARAM− (RNFL superior: ARAM+ 74.2 μm, ARAM− 77.5 μm; RNFL temporal: ARAM+ 46.8 μm, ARAM− 53.0 μm, p<0.001; and RNFL inferior: ARAM+ 63.2 μm, ARAM− 73.1 μm, p<0.001. Within the same eye, ARAM+ showed a lower retinal sensitivity compared to ARAM− ([ARAM− (11.13 dB] − [ARAM+ (9.56 dB = 1.57 dB; p=0.25. The proportion of ARAM+ per eye correlated strongly with reduced retinal light sensitivity (p=0.02, corresponding lower peripapillary RNFL thickness (p=0.02, and lower RNFL temporal quadrant thickness (p<0.01, but not with greater age (p=0.45. Conclusion. ARAM was more frequently identified in the eyes with a lower retinal sensitivity and peripapillary RNFL thickness and may be a clinical sign in the macula for an advanced stage of POAG.
9. The Crystal Structure of Yeast Protein Disulfide Isomerase Suggests Cooperativity Between Its Active Sites
Energy Technology Data Exchange (ETDEWEB)
Tian,G.; Xiang, S.; Noiva, R.; Lennarz, W.; Schindelin, H.
2006-01-01
Protein disulfide isomerase plays a key role in catalyzing the folding of secretory proteins. It features two catalytically inactive thioredoxin domains inserted between two catalytically active thioredoxin domains and an acidic C-terminal tail. The crystal structure of yeast PDI reveals that the four thioredoxin domains are arranged in the shape of a twisted 'U' with the active sites facing each other across the long sides of the 'U.' The inside surface of the 'U' is enriched in hydrophobic residues, thereby facilitating interactions with misfolded proteins. The domain arrangement, active site location, and surface features strikingly resemble the Escherichia coli DsbC and DsbG protein disulfide isomerases. Biochemical studies demonstrate that all domains of PDI, including the C-terminal tail, are required for full catalytic activity. The structure defines a framework for rationalizing the differences between the two active sites and their respective roles in catalyzing the formation and rearrangement of disulfide bonds.
10. Interaction of aspartic acid-104 and proline-287 with the active site of m-calpain.
Science.gov (United States)
Arthur, J S; Elce, J S
1996-01-01
In an ongoing study of the mechanisms of calpain catalysis and Ca(2+)-induced activation, the effects of Asp-104-->Ser and Pro-287-->Ser large subunit mutations on m-calpain activity, the pH-activity profile, Ca(2+)-sensitivity, and autolysis were measured. The importance of these positions was suggested by sequence comparisons between the calpain and papain families of cysteine proteinases. Asp-104 is adjacent to the active-site Cys-105, and Pro-287 is adjacent to the active-site Asn-286 and probably to the active-site His-262; both Asp-104 and Pro-287 are absolutely conserved in the known calpains, but are replaced by highly conserved serine residues in the papains. The single mutants had approx. 10-15% of wild-type activity, due mainly to a decrease in kcat, since Km was only slightly increased. The Pro-287-->Ser mutation appeared to cause a local perturbation of the catalytic Cys-105/His-262 catalytic ion pair, reducing its efficiency without major effect on the conformation and stability of the enzyme. The Asp-104-->Ser mutation caused a marked narrowing of the pH-activity curve, a 9-fold increase in Ca2+ requirement, and an acceleration of autolysis, when compared with the wild-type enzyme. The results indicated that Asp-104 alters the nature of its interaction with the catalytic ion pair during Ca(2+)-induced conformational change in calpain. This interaction may be direct or indirect, but is important in activation of the enzyme. PMID:8912692
11. Molecular modeling of sialyloligosaccharide fragments into the active site of influenza virus N9 neuraminidase.
Science.gov (United States)
Veluraja, K; Suresh, M X; Christlet, T H; Rafi, Z A
2001-08-01
Molecular modeling studies have been carried out to investigate the interactions between substrate sialyloligosaccharide (SOS) fragments bearing different glycosidic linkages and influenza virus N9 neuraminidase, a surface glycoprotein of influenza virus subtype N9. The studies revealed that the allowed orientation for sialic acid (SA) is less than 1% in the Eulerian space at the active site. The active site of this enzyme has enough space to accommodate various SOS fragments, NeuNAcalpha(2-3)Gal, NeuNAcalpha(2-6)Gal, NeuNAcalpha(2-8)NeuNAc and NeuNAcalpha(2-9)NeuNAc, but on specific conformations. In the bound conformation, among these substrates there exists a conformational similarity leading to a structural similarity, which may be an essential requirement for the cleavage activity of the neuraminidases irrespective of the type of glycosidic linkage.
12. Selective targeting of the conserved active site cysteine of Mycobacterium tuberculosis methionine aminopeptidase with electrophilic reagents.
Science.gov (United States)
Reddi, Ravikumar; Arya, Tarun; Kishor, Chandan; Gumpena, Rajesh; Ganji, Roopa J; Bhukya, Supriya; Addlagatta, Anthony
2014-09-01
Methionine aminopeptidases (MetAPs) cleave initiator methionine from ~ 70% of the newly synthesized proteins in every living cell, and specific inhibition or knockdown of this function is detrimental. MetAPs are metalloenzymes, and are broadly classified into two subtypes, type I and type II. Bacteria contain only type I MetAPs, and the active site of these enzymes contains a conserved cysteine. By contrast, in type II enzymes the analogous position is occupied by a conserved glycine. Here, we report the reactivity of the active site cysteine in a type I MetAP, MetAP1c, of Mycobacterium tuberculosis (MtMetAP1c) towards highly selective cysteine-specific reagents. The authenticity of selective modification of Cys105 of MtMetAP1c was established by using site-directed mutagenesis and crystal structure determination of covalent and noncovalent complexes. On the basis of these observations, we propose that metal ions in the active site assist in the covalent modification of Cys105 by orienting the reagents appropriately for a successful reaction. These studies establish, for the first time, that the conserved cysteine of type I MetAPs can be targeted for selective inhibition, and we believe that this chemistry can be exploited for further drug discovery efforts regarding microbial MetAPs.
13. Comparison of body-powered voluntary opening and voluntary closing prehensor for activities of daily life
OpenAIRE
Kelsey Berning; Sarah Cohick; Reva Johnson, MS; Laura Ann Miller, PhD, CP; Jonathon W. Sensinger, PhD
2014-01-01
Persons with an upper-limb amputation who use a body-powered prosthesis typically control the prehensor through contralateral shoulder movement, which is transmitted through a Bowden cable. Increased cable tension either opens or closes the prehensor; when tension is released, some passive element, such as a spring, returns the prehensor to the default state (closed or open). In this study, we used the Southampton Hand Assessment Procedure to examine functional differences between these two t...
14. Radiological audit of remedial action activities at the processing site, transfer site, and Cheney disposal site Grand Junction, Colorado: Audit date, August 9--11, 1993. Final report
Energy Technology Data Exchange (ETDEWEB)
1993-08-01
The Uranium Mill Tailing Remedial Action (UMTRA) Projects Technical Assistance Contractor (TAC) performed a radiological audit of the Remedial Action Contractor (RAC), MK-Ferguson and CWM Federal Environmental Services, Inc., at the processing site, transfer site, and Cheney disposal site in Grand Junction, Colorado. Jim Hylko and Bill James of the TAC conducted this audit August 9 through 11, 1993. Bob Cornish and Frank Bosiljevec represented the US Department of Energy (DOE). This report presents one programmatic finding, eleven site-specific observations, one good practice, and four programmatic observations.
15. Intermetallic Alloys as CO Electroreduction Catalysts-Role of Isolated Active Sites
DEFF Research Database (Denmark)
2014-01-01
binary bulk alloys forming from these elements have been investigated using density functional theory calculations. The electronic and geometric properties of the catalyst surface can be tuned by varying the size of the active centers and the elements forming them. We have identified six different...... potentially selective intermetallic surfaces on which CO can be reduced to methanol at potentials comparable to or even slightly positive than those for CO/CO2 reduction to methane on Cu. Common features shared by most of the selective alloys are single TM sites. The role of single sites is to block parasitic...
16. Technical basis for classification of low-activity waste fraction from Hanford site tanks
Energy Technology Data Exchange (ETDEWEB)
Petersen, C.A., Westinghouse Hanford
1996-07-17
The overall objective of this report is to provide a technical basis to support a U.S. Nuclear Regulatory Commission determination to classify the low-activity waste from the Hanford Site single-shell and double-shell tanks as incidental wastes after removal of additional radionuclides and immobilization.The proposed processing method, in addition to the previous radionuclide removal efforts, will remove the largest practical amount of total site radioactivity, attributable to high-level wastes, for disposal in a deep geologic repository. The remainder of the waste would be considered incidental waste and could be disposed onsite.
17. Technical basis for classification of low-activity waste fraction from Hanford site tanks
Energy Technology Data Exchange (ETDEWEB)
Petersen, C.A.
1996-09-20
The overall objective of this report is to provide a technical basis to support a U.S. Nuclear Regulatory Commission determination to classify the low-activity waste from the Hanford Site single-shell and double-shell tanks as incidental wastes after removal of additional radionuclides and immobilization.The proposed processing method, in addition to the previous radionuclide removal efforts, will remove the largest practical amount of total site radioactivity, attributable to high-level waste, for disposal is a deep geologic repository. The remainder of the waste would be considered incidental waste and could be disposed onsite.
18. Communication: Active space decomposition with multiple sites: Density matrix renormalization group algorithm
Energy Technology Data Exchange (ETDEWEB)
Parker, Shane M.; Shiozaki, Toru [Department of Chemistry, Northwestern University, 2145 Sheridan Rd., Evanston, Illinois 60208 (United States)
2014-12-07
We extend the active space decomposition method, recently developed by us, to more than two active sites using the density matrix renormalization group algorithm. The fragment wave functions are described by complete or restricted active-space wave functions. Numerical results are shown on a benzene pentamer and a perylene diimide trimer. It is found that the truncation errors in our method decrease almost exponentially with respect to the number of renormalization states M, allowing for numerically exact calculations (to a few μE{sub h} or less) with M = 128 in both cases. This rapid convergence is because the renormalization steps are used only for the interfragment electron correlation.
19. Active space decomposition with multiple sites: Density matrix renormalization group algorithm
CERN Document Server
Parker, Shane M
2014-01-01
We extend the active space decomposition method, recently developed by us, to more than two active sites using the density matrix renormalization group algorithm. The fragment wave functions are described by complete or restricted active-space wave functions. Numerical results are shown on a benzene pentamer and a perylene diimide trimer. It is found that the truncation errors in our method decrease almost exponentially with respect to the number of renormalization states M, allowing for numerically exact calculations (to a few {\\mu}Eh or less) with M = 128 in both cases, which is in contrast to conventional ab initio density matrix renormalization group.
20. Communication: Active space decomposition with multiple sites: density matrix renormalization group algorithm.
Science.gov (United States)
Parker, Shane M; Shiozaki, Toru
2014-12-07
We extend the active space decomposition method, recently developed by us, to more than two active sites using the density matrix renormalization group algorithm. The fragment wave functions are described by complete or restricted active-space wave functions. Numerical results are shown on a benzene pentamer and a perylene diimide trimer. It is found that the truncation errors in our method decrease almost exponentially with respect to the number of renormalization states M, allowing for numerically exact calculations (to a few μE(h) or less) with M = 128 in both cases. This rapid convergence is because the renormalization steps are used only for the interfragment electron correlation.
1. Controlling activation site density by low-energy far-field stimulation in cardiac tissue
Science.gov (United States)
Hörning, Marcel; Takagi, Seiji; Yoshikawa, Kenichi
2012-06-01
Tachycardia and fibrillation are potentially fatal arrhythmias associated with the formation of rotating spiral waves in the heart. Presently, the termination of these types of arrhythmia is achieved by use of antitachycardia pacing or cardioversion. However, these techniques have serious drawbacks, in that they either have limited application or produce undesirable side effects. Low-energy far-field stimulation has recently been proposed as a superior therapy. This proposed therapeutic method would exploit the phenomenon in which the application of low-energy far-field shocks induces a large number of activation sites (“virtual electrodes”) in tissue. It has been found that the formation of such sites can lead to the termination of undesired states in the heart and the restoration of normal beating. In this study we investigate a particular aspect of this method. Here we seek to determine how the activation site density depends on the applied electric field through in vitro experiments carried out on neonatal rat cardiac tissue cultures. The results indicate that the activation site density increases exponentially as a function of the intracellular conductivity and the level of cell isotropy. Additionally, we report numerical results obtained from bidomain simulations of the Beeler-Reuter model that are quantitatively consistent with our experimental results. Also, we derive an intuitive analytical framework that describes the activation site density and provides useful information for determining the ratio of longitudinal to transverse conductivity in a cardiac tissue culture. The results obtained here should be useful in the development of an actual therapeutic method based on low-energy far-field pacing. In addition, they provide a deeper understanding of the intrinsic properties of cardiac cells.
2. Human 15-LOX-1 active site mutations alter inhibitor binding and decrease potency.
Science.gov (United States)
Armstrong, Michelle; van Hoorebeke, Christopher; Horn, Thomas; Deschamps, Joshua; Freedman, J Cody; Kalyanaraman, Chakrapani; Jacobson, Matthew P; Holman, Theodore
2016-11-01
Human 15-lipoxygenase-1 (h15-LOX-1 or h12/15-LOX) reacts with polyunsaturated fatty acids and produces bioactive lipid derivatives that are implicated in many important human diseases. One such disease is stroke, which is the fifth leading cause of death and the first leading cause of disability in America. The discovery of h15-LOX-1 inhibitors could potentially lead to novel therapeutics in the treatment of stroke, however, little is known about the inhibitor/active site interaction. This study utilizes site-directed mutagenesis, guided in part by molecular modeling, to gain a better structural understanding of inhibitor interactions within the active site. We have generated eight mutants (R402L, R404L, F414I, F414W, E356Q, Q547L, L407A, I417A) of h15-LOX-1 to determine whether these active site residues interact with two h15-LOX-1 inhibitors, ML351 and an ML094 derivative, compound 18. IC50 values and steady-state inhibition kinetics were determined for the eight mutants, with four of the mutants affecting inhibitor potency relative to wild type h15-LOX-1 (F414I, F414W, E356Q and L407A). The data indicate that ML351 and compound 18, bind in a similar manner in the active site to an aromatic pocket close to F414 but have subtle differences in their specific binding modes. This information establishes the binding mode for ML094 and ML351 and will be leveraged to develop next-generation inhibitors.
3. Widely available active sites on Ni2P for electrochemical hydrogen evolution - insights from first principles calculations
DEFF Research Database (Denmark)
Hansen, Martin Hangaard; Stern, Lucas-Alexandre; Feng, Ligang;
2015-01-01
We present insights into the mechanism and the active site for hydrogen evolution on nickel phosphide (Ni2P). Ni2P was recently discovered to be a very active non-precious hydrogen evolution catalyst. Current literature attributes the activity of Ni2P to a particular site on the (0001) facet. In ...
4. Persistent organic pollutants in breast milk of mothers residing around an open dumping site in Kolkata, India: specific dioxin-like PCB levels and fish as a potential source.
Science.gov (United States)
Someya, Masayuki; Ohtake, Masako; Kunisue, Tatsuya; Subramanian, Annamalai; Takahashi, Shin; Chakraborty, Paromita; Ramachandran, Ramesh; Tanabe, Shinsuke
2010-01-01
Concentrations of persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and organochlorine pesticides were measured in human breast milk collected from mothers residing near an open dumping site and a reference site in Kolkata, India during 2004-2005. POPs were detected in all the human milk samples analyzed, suggesting that residents of Kolkata are widely exposed to these contaminants. Concentrations of dioxin-like PCBs in the samples from the dumping site were significantly higher than in the reference site samples, whereas no such difference was found for PCDDs and PCDFs. In addition, significantly higher concentrations of total PCBs were also observed in the samples from the dumping site than the reference site. Interestingly, concentrations of total and dioxin-like PCBs in the breast milk of mothers from the dumping site significantly increased with the number of years of residence near the dumping site. These results indicate that significant pollution sources of PCBs are present in the dumping site of Kolkata and the residents living around are exposed to relatively higher levels of PCBs. When the residue levels of dioxins and related compounds in fish collected from ponds near the Kolkata dumping site and the reference site were measured, it was found that dioxin-like PCB and TEQ levels in fish from the dumping site were notably higher than those from the reference site. This result indicates that fish is a potential source of PCBs for residents living near the Kolkata dumping site.
5. Multiple nucleophilic elbows leading to multiple active sites in a single module esterase from Sorangium cellulosum
DEFF Research Database (Denmark)
Udatha, D.B.R.K. Gupta; Madsen, Karina Marie; Panagiotou, Gianni;
2015-01-01
The catalytic residues in carbohydrate esterase enzyme families constitute a highly conserved triad: serine, histidine and aspartic acid. This catalytic triad is generally located in a very sharp turn of the protein backbone structure, called the nucleophilic elbow and identified by the consensus...... sequence GXSXG. An esterase from Sorangium cellulosum Soce56 that contains five nucleophilic elbows was cloned and expressed in Escherichia coli and the function of each nucleophilic elbowed site was characterized. In order to elucidate the function of each nucleophilic elbow, site directed mutagenesis...... was used to generate variants with deactivated nucleophilic elbows and the functional promiscuity was analyzed. In silico analysis together with enzymological characterization interestingly showed that each nucleophilic elbow formed a local active site with varied substrate specificities and affinities...
6. Novel active comb-shaped dry electrode for EEG measurement in hairy site.
Science.gov (United States)
Huang, Yan-Jun; Wu, Chung-Yu; Wong, Alice May-Kuen; Lin, Bor-Shyh
2015-01-01
Electroencephalography (EEG) is an important biopotential, and has been widely applied in clinical applications. The conventional EEG electrode with conductive gels is usually used for measuring EEG. However, the use of conductive gel also encounters with the issue of drying and hardening. Recently, many dry EEG electrodes based on different conductive materials and techniques were proposed to solve the previous issue. However, measuring EEG in the hairy site is still a difficult challenge. In this study, a novel active comb-shaped dry electrode was proposed to measure EEG in hairy site. Different form other comb-shaped or spike-shaped dry electrodes, it can provide more excellent performance of avoiding the signal attenuation, phase distortion, and the reduction of common mode rejection ratio. Even under walking motion, it can effectively acquire EEG in hairy site. Finally, the experiments for alpha rhythm and steady-state visually evoked potential were also tested to validate the proposed electrode.
7. Human glutaminyl cyclase and bacterial zinc aminopeptidase share a common fold and active site
Directory of Open Access Journals (Sweden)
Misquitta Stephanie A
2004-02-01
Full Text Available Abstract Background Glutaminyl cyclase (QC forms the pyroglutamyl residue at the amino terminus of numerous secretory peptides and proteins. We previously proposed the mammalian QC has some features in common with zinc aminopeptidases. We now have generated a structural model for human QC based on the aminopeptidase fold (pdb code 1AMP and mutated the apparent active site residues to assess their role in QC catalysis. Results The structural model proposed here for human QC, deposited in the protein databank as 1MOI, is supported by a variety of fold prediction programs, by the circular dichroism spectrum, and by the presence of the disulfide. Mutagenesis of the six active site residues present in both 1AMP and QC reveal essential roles for the two histidines (140 and 330, QC numbering and the two glutamates (201 and 202, while the two aspartates (159 and 248 appear to play no catalytic role. ICP-MS analysis shows less than stoichiometric zinc (0.3:1 in the purified enzyme. Conclusions We conclude that human pituitary glutaminyl cyclase and bacterial zinc aminopeptidase share a common fold and active site residues. In contrast to the aminopeptidase, however, QC does not appear to require zinc for enzymatic activity.
8. Synergistic effect between defect sites and functional groups on the hydrolysis of cellulose over activated carbon.
Science.gov (United States)
Foo, Guo Shiou; Sievers, Carsten
2015-02-01
The chemical oxidation of activated carbon by H2 O2 and H2 SO4 is investigated, structural and chemical modifications are characterized, and the materials are used as catalysts for the hydrolysis of cellulose. Treatment with H2 O2 enlarges the pore size and imparts functional groups such as phenols, lactones, and carboxylic acids. H2 SO4 treatment targets the edges of carbon sheets primarily, and this effect is more pronounced with a higher temperature. Adsorption isotherms demonstrate that the adsorption of oligomers on functionalized carbon is dominated by van der Waals forces. The materials treated chemically are active for the hydrolysis of cellulose despite the relative weakness of most of their acid sites. It is proposed that a synergistic effect between defect sites and functional groups enhances the activity by inducing a conformational change in the glucan chains if they are adsorbed at defect sites. This activates the glycosidic bonds for hydrolysis by in-plane functional groups. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
9. Progress report on decommissioning activities at the Fernald Environmental Management Project (FEMP) site
Energy Technology Data Exchange (ETDEWEB)
NONE
1998-07-01
The Fernald Environmental Management Project (FEMP), is located about 18 miles northwest of Cincinnati, Ohio. Between 1953 and 1989, the facility, then called the Feed Material Production Center or FMPC, produced uranium metal products used in the eventual production of weapons grade material for use by other US Department of Energy (DOE) sites. In 1989, FMPCs production was suspended by the federal government in order to focus resources on environmental restoration versus defense production. In 1992, Fluor Daniel Fernald assumed responsibility for managing all cleanup activities at the FEMP under contract to the DOE. In 1990, as part of the remediation effort, the site was divided into five operable units based on physical proximity of contaminated areas, similar amounts of types of contamination, or the potential for a similar technology to be used in cleanup activities. This report continues the outline of the decontamination and decommissioning (D and D) activities at the FEMP site Operable Unit 3 (OU3) and provides an update on the status of the decommissioning activities. OU3, the Facilities Closure and Demolition Project, involves the remediation of more than 200 uranium processing facilities. The mission of the project is to remove nuclear materials stored in these buildings, then perform the clean out of the buildings and equipment, and decontaminate and dismantle the facilities.
10. Active site dynamics in NADH oxidase from Thermus thermophilus studied by NMR spin relaxation.
Science.gov (United States)
Miletti, Teresa; Farber, Patrick J; Mittermaier, Anthony
2011-09-01
We have characterized the backbone dynamics of NADH oxidase from Thermus thermophilus (NOX) using a recently-developed suite of NMR experiments designed to isolate exchange broadening, together with (15)N R (1), R (1ρ ), and {(1)H}-(15)N steady-state NOE relaxation measurements performed at 11.7 and 18.8 T. NOX is a 54 kDa homodimeric enzyme that belongs to a family of structurally homologous flavin reductases and nitroreductases with many potential biotechnology applications. Prior studies have suggested that flexibility is involved in the catalytic mechanism of the enzyme. The active site residue W47 was previously identified as being particularly important, as its level of solvent exposure correlates with enzyme activity, and it was observed to undergo "gating" motions in computer simulations. The NMR data are consistent with these findings. Signals from W47 are dynamically broadened beyond detection and several other residues in the active site have significant R ( ex ) contributions to transverse relaxation rates. In addition, the backbone of S193, whose side chain hydroxyl proton hydrogen bonds directly with the FMN cofactor, exhibits extensive mobility on the ns-ps timescale. We hypothesize that these motions may facilitate structural rearrangements of the active site that allow NOX to accept both FMN and FAD as cofactors.
11. Redox-active on-surface polymerization of single-site divalent cations from pure metals by a ketone-functionalized phenanthroline
Energy Technology Data Exchange (ETDEWEB)
Skomski, Daniel; Tempas, Christopher D.; Bukowski, Gregory S.; Smith, Kevin A.; Tait, Steven L., E-mail: [email protected] [Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405 (United States)
2015-03-14
Metallic iron, chromium, or platinum mixing with a ketone-functionalized phenanthroline ligand on a single crystal gold surface demonstrates redox activity to a well-defined oxidation state and assembly into thermally stable, one dimensional, polymeric chains. The diverging ligand geometry incorporates redox-active sub-units and bi-dentate binding sites. The gold surface provides a stable adsorption environment and directs growth of the polymeric chains, but is inert with regard to the redox chemistry. These systems are characterized by scanning tunnelling microscopy, non-contact atomic force microscopy, and X-ray photoelectron spectroscopy under ultra-high vacuum conditions. The relative propensity of the metals to interact with the ketone group is examined, and it is found that Fe and Cr more readily complex the ligand than Pt. The formation and stabilization of well-defined transition metal single-sites at surfaces may open new routes to achieve higher selectivity in heterogeneous catalysts.
12. A NMR and MD study of the active site of factor Xa by selective inhibitors
Science.gov (United States)
Doan, B. T.; Fraternali, F.; Do, Q. T.; Atkinson, R. A.; Palmas, P.; Sklenar, V.; Wildgoose, P.; Strop, P.; Saudek, V.
1998-02-01
The structure of two selective inhibitors obtained by the screening of a vast combinatorial library, Ac-Tyr-Ile-Arg-Ile-NH2 and Ac-(4-amino-Phe)-(Cyc.-Gly)-NH2, in the active site of the blood clotting enzyme factor Xa was determined using transferred NOE NMR and simulated annealing (SA) under NMR constraints. The refined structures of the inhibitors were docked in the active site and SA was performed inside the enzyme which has been kept as a rigid charged template. The final structures were optimised by molecular dynamics simulation of the complexes in water. The inhibitors assume a compact, very well defined conformation embedded in the binding site without blocking the catalysis. The model allows to explain the mode of action, affinity and specificity. L'étude structurale d'inhibiteurs du facteur Xa, une enzyme de coagulation, obtenus par chimie combinatoire : Ac-Tyr-Ile-Arg-Ile-NH2, Ac-(4-amino-Phe)-(Cyc.-Gly)-NH2, a été réalisée par RMN NOE de transfert et modélisation moléculaire. Les structures ont été calculées sous contraintes RMN : géométrie de distance, recuit simulé et minimisation, affinées par une recherche conformationnelle et recuit de l'inhibiteur placé dans le site actif et optimisées par simulation de dynamique moléculaire du complexe dans l'eau. L'inhibiteur présente une structure compacte positionnée dans le site d'interaction hors d'accès du site catalytique. Ce modèle permet d'expliquer le mode d'action, l'affinité et la spécificité des peptides.
13. Effect of methylprednisolone on the oxidative burst activity, adhesion molecules and clinical outcome following open heart surgery
DEFF Research Database (Denmark)
Toft, P; Christiansen, K; Tønnesen, Else Kirstine;
1997-01-01
on granulocytes and improve clinical outcome. Sixteen patients undergoing open heart surgery participated in the study. Eight were randomized to receive methylprednisolone (30 mg/kg intravenously) at the start of anaesthesia while eight patients served as a control group. The oxidative burst was measured flow...... not improve the weaning from the ventilator or reduce the stay in the intensive-care unit. In conclusion, treatment with steroids prevented hyperthermia following open heart surgery with CPB and reduced capillary leak during ECC. Methylprednisolone, however, did not reduce the oxidative burst activity......Following cardiac surgery with cardiopulmonary bypass (CPB), activated granulocytes may be involved with ischaemia/ reperfusion injury. The purpose of this study was to investigate whether steroids could reduce the oxidative burst activity of granulocytes, the expression of adhesion molecules...
14. Efficient and Selective Uptake of TcO4(-) by a Cationic Metal-Organic Framework Material with Open Ag(+) Sites.
Science.gov (United States)
Sheng, Daopeng; Zhu, Lin; Xu, Chao; Xiao, Chengliang; Wang, Yanlong; Wang, Yaxing; Chen, Lanhua; Diwu, Juan; Chen, Jing; Chai, Zhifang; Albrecht-Schmitt, Thomas E; Wang, Shuao
2017-03-21
(99)Tc is one of the most problematic radioisotopes in used nuclear fuel owing to its combined features of high fission yield, long half-life, and high environmental mobility. There are only a handful of functional materials that can remove TcO4(-) anion from aqueous solution and identifying for new, stable materials with high anion-exchange capacities, fast kinetics, and good selectivity remains a challenge. We report here an 8-fold interpenetrated three-dimensional cationic metal-organic framework material, SCU-100, which is assembled from a tetradentate neutral nitrogen-donor ligand and two-coordinate Ag(+) cations as potential open metal sites. The structure also contains a series of 1D channels filled with unbound nitrate anions. SCU-100 maintains its crystallinity in aqueous solution over a wide pH range from 1 to 13 and exhibits excellent β and γ radiation-resistance. Initial anion exchange studies show that SCU-100 is able to both quantitatively and rapidly remove TcO4(-) from water within 30 min. The exchange capacity for the surrogate ReO4(-) reaches up to 541 mg/g and the distribution coefficient Kd is up to 1.9 × 10(5) mL/g, which are significantly higher than all previously tested inorganic anion sorbent materials. More importantly, SCU-100 can selectively capture TcO4(-) in the presence of large excess of competitive anions (NO3(-), SO4(2-), CO3(2-), and PO4(3-)) and remove as much as 87% of TcO4(-) from the Hanford low-level waste melter off-gas scrubber simulant stream within 2 h. The sorption mechanism is well elucidated by single crystal X-ray diffraction, showing that the sorbed ReO4(-) anion is able to selectively coordinate to the open Ag(+) sites forming Ag-O-Re bonds and a series of hydrogen bonds. This further leads to a single-crystal-to-single-crystal transformation from an 8-fold interpenetrated framework with disordered nitrate anions to a 4-fold interpenetrated framework with fully ordered ReO4(-) anions. This work represents a
15. Adsorption and separation of CO{sub 2} on Fe(II)-MOF-74: Effect of the open metal coordination site
Energy Technology Data Exchange (ETDEWEB)
Lou, Wolong; Yang, Jiangfeng; Li, Libo; Li, Jinping, E-mail: [email protected]
2014-05-01
We describe the successful synthesis of Fe{sub 2}(dobdc) (dobdc{sup 4−}=2, 5-dioxido-1, 4-benzenedicarboxylate), which has an open metal coordination site Fe(II), and investigate the adsorption properties of three important molecules CO{sub 2}, CH{sub 4} and N{sub 2} on Fe{sub 2}(dobdc) and an oxidized analog, Fe{sub 2}(O{sub 2})(dobdc). We found that CO{sub 2} adsorption isotherm of Fe{sub 2}(dobdc) at 10 bar was very different from Fe{sub 2}(O{sub 2})(dobdc), with the capacities of 144.5 cm{sup 3} g{sup −1} and 98.1 cm{sup 3} g{sup −1}, respectively. The adsorption capacities for CH{sub 4} were 75.8 cm{sup 3} g{sup −1} and 36.8 cm{sup 3} g{sup −1}, respectively, at 10 bar in these materials. Using ideal adsorbed solution theory (IAST), we obtain the adsorption selectivity for CO{sub 2} using equimolar mixtures of CO{sub 2}/CH{sub 4} and CO{sub 2}/N{sub 2} with Fe{sub 2}(dobdc) and Fe{sub 2}(O{sub 2})(dobdc) as a function of pressure. Fe{sub 2}(dobdc) has a higher, more stable separation factor. - Graphical abstract: The selectivity of CO{sub 2}/CH{sub 4} mixture (50%/50%) on Fe{sub 2}(dobdc) and Fe{sub 2}(O{sub 2})(dobdc). - Highlights: • We explored the contrastive adsorption of CO{sub 2}, CH{sub 4}, and N{sub 2} in Fe{sub 2}(dobdc) and Fe{sub 2}(O{sub 2})(dobdc) for the first time. • Through IAST, we obtain the adsorption selectivity for CO{sub 2} from the equimolar mixture of CO{sub 2}/CH{sub 4} and CO{sub 2}/N{sub 2} for Fe{sub 2}(dobdc) and Fe{sub 2}(O{sub 2})(dobdc). • We determined that the open coordination site of Fe(II) is the main reason for different adsorption performances.
16. Soil pollution with trace elements at selected sites in Romania studied by instrumental neutron activation analysis
Energy Technology Data Exchange (ETDEWEB)
Pantelica, A. [Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Magurele, Ilfov County (Romania); Carmo Freitas, M. do [Technological and Nuclear Institute (ITN), Sacavem (Portugal); Ene, A. [Dunarea de Jos Univ. of Galati (Romania). Dept. of Chemistry, Physics and Environment; Steinnes, E. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Chemistry
2013-03-01
Instrumental neutron activation analysis (INAA) was used to determine concentrations of 42 elements in samples of surface soil collected at seven sites polluted from various anthropogenic activities and a control site in a relatively clean area. Elements studied were Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Eu, Fe, Gd, Hf, Hg, K, La, Lu, Mg, Mn, Mo, Na, Nd, Ni, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Ti, U, V, W, Yb, Zn, and Zr. The results are compared with data for trace elements atmospheric deposition in lichen transplants from the same sites. The most severe soil contamination was observed at Copsa Mica from non-ferrous metallurgy. Appreciable soil contamination was also indicated at Baia Mare (non-ferrous mining and metallurgy), Deva (coal-fired power plant, cement and building materials industry), Galati (ferrous metallurgy), Magurele and Afumati (general urban pollution), and Oradea (chemical and light industries). In most cases excessive levels of toxic metals in soils matched correspondingly high values in lichen transplants. Compared to Romanian norms, legal upper limits were exceeded for Zn and Cd at Copsa Mica. Also, As and Sb occurred in excessive levels at given sites. (orig.)
17. Assessment of Tritium Activity in Groundwater at the Nuclear Objects Sites in Lithuania
Directory of Open Access Journals (Sweden)
Vigilija Cidzikienė
2014-01-01
Full Text Available The assessment of nuclear objects sites in Lithuania, including groundwater characterization, took place in the last few years. Tritium activity in groundwater is a very useful tool for determining how groundwater systems function. Natural and artificial tritium was measured in 8 wells in different layers (from 1.5 to 15 meters depth. The results were compared with other regions of Lithuania also. The evaluated tritium activities varied from 1.8 to 6.4 Bq/L at nuclear objects sites in Lithuania and they are coming to background level (1.83 Bq/L and other places in Lithuania. The data show, that groundwater at the nuclear power objects sites is not contaminated with artificial tritium. In this work, the vertical tritium transfer from soil water to the groundwater well at nuclear objects site was estimated. The data show that the main factor for vertical tritium transfer to the well depends on the depth of wells.
18. Irreversible Oxidation of the Active-site Cysteine of Peroxiredoxin to Cysteine Sulfonic Acid for Enhanced Molecular Chaperone Activity*
OpenAIRE
2008-01-01
The thiol (–SH) of the active cysteine residue in peroxiredoxin (Prx) is known to be reversibly hyperoxidized to cysteine sulfinic acid (–SO2H), which can be reduced back to thiol by sulfiredoxin/sestrin. However, hyperoxidized Prx of an irreversible nature has not been reported yet. Using an antibody developed against the sulfonylated (–SO3H) yeast Prx (Tsa1p) active-site peptide (AFTFVCPTEI), we observed an increase in the immunoblot intensity in proportion to the ...
19. Linde FUSRAP Site Remediation: Engineering Challenges and Solutions of Remedial Activities on an Active Industrial Facility - 13506
Energy Technology Data Exchange (ETDEWEB)
Beres, Christopher M.; Fort, E. Joseph [Cabrera Services, Inc., 473 Silver Lane, East Hartford, CT 06118 (United States); Boyle, James D. [United States Army Corps of Engineers - Buffalo, 1776 Niagara Street, Buffalo, NY 14207 (United States)
2013-07-01
The Linde FUSRAP Site (Linde) is located in Tonawanda, New York at a major research and development facility for Praxair, Inc. (Praxair). Successful remediation activities at Linde combines meeting cleanup objectives of radiological contamination while minimizing impacts to Praxair business operations. The unique use of Praxair's property coupled with an array of active and abandoned utilities poses many engineering and operational challenges; each of which has been overcome during the remedial action at Linde. The U.S. Army Corps of Engineers - Buffalo District (USACE) and CABRERA SERVICES, INC. (CABRERA) have successfully faced engineering challenges such as relocation of an aboveground structure, structural protection of an active water line, and installation of active mechanical, electrical, and communication utilities to perform remediation. As remediation nears completion, continued success of engineering challenges is critical as remaining activities exist in the vicinity of infrastructure essential to business operations; an electrical substation and duct bank providing power throughout the Praxair facility. Emphasis on engineering and operations through final remediation and into site restoration will allow for the safe and successful completion of the project. (authors)
20. Synthesis of supported bimetallic nanoparticles with controlled size and composition distributions for active site elucidation
Energy Technology Data Exchange (ETDEWEB)
Hakim, Sikander H.; Sener, Canan; Alba Rubio, Ana C.; Gostanian, Thomas M.; O' neill, Brandon J; Ribeiro, Fabio H.; Miller, Jeffrey T.; Dumesic, James A
2015-08-01
Elucidation of active sites in supported bimetallic catalysts is complicated by the high level of dispersity in the nanoparticle size and composition that is inherent in conventional methods of catalyst preparation. We present a synthesis strategy that leads to highly dispersed, bimetallic nanoparticles with uniform particle size and composition by means of controlled surface reactions. We demonstrate the synthesis of three systems, RhMo, PtMo, and RhRe, consisting of a highly reducible metal with an oxophilic promoter. These catalysts are characterized by FTIR, CO chemisorption, STEM/EDS, TPR, and XAS analysis. The catalytic properties of these bimetallic nanoparticles were probed for the selective CO hydrogenolysis of (hydroxymethyl)tetrahydropyran to produce 1,6 hexanediol. Based on the characterization results and reactivity trends, the active sites in the hydrogenolysis reaction are identified to be small ensembles of the more noble metal (Rh, Pt) adjacent to highly reduced moieties of the more oxophilic metal (Mo, Re).
1. Visualization of the Differential Transition State Stabilization within the Active Site Environment
Directory of Open Access Journals (Sweden)
Jerzy Leszczynski
2004-05-01
Full Text Available Abstract: Increasing interest in the enzymatic reaction mechanisms and in the nature of catalytic effects in enzymes causes the need of appropriate visualization methods. A new interactive method to investigate catalytic effects using differential transition state stabilization approach (DTSS [1, 2] is presented. The catalytic properties of the active site of cytidine deaminase (E.C. 3.5.4.5 is visualized in the form of differential electrostatic properties. The visualization was implemented using scripting interface of VMD [3]. Cumulative Atomic Multipole Moments (CAMM [4,5,6] were utilized for efficient yet accurate evaluation of the electrostatic properties. The implementation is efficient enough for interactive presentation of catalytic effects in the active site of the enzyme due to transition state or substrate movement. This system of visualization of DTTS approach can be potentially used to validate hypotheses regarding the catalytic mechanism or to study binding properties of transition state analogues.
2. Dynamics of water molecules in the active-site cavity of human cytochromes P450
DEFF Research Database (Denmark)
Rydberg, Patrik; Rod, Thomas Holm; Olsen, Lars;
2007-01-01
have quite big cavities, with 41 water molecules on average in 2C8 and 54-58 in 2C9 and 3A4, giving a water volume of 1500-2100 A3. The two crystal structures of 2C9 differ quite appreciably, whereas those of 3A4 are quite similar. The active-site cavity is connected to the surroundings by three to six......We have studied the dynamics of water molecules in six crystal structures of four human cytochromes P450, 2A6, 2C8, 2C9, and 3A4, with molecular dynamics simulations. In the crystal structures, only a few water molecules are seen and the reported sizes of the active-site cavity vary a lot...
3. Extreme electric fields power catalysis in the active site of ketosteroid isomerase.
Science.gov (United States)
Fried, Stephen D; Bagchi, Sayan; Boxer, Steven G
2014-12-19
Enzymes use protein architecture to impose specific electrostatic fields onto their bound substrates, but the magnitude and catalytic effect of these electric fields have proven difficult to quantify with standard experimental approaches. Using vibrational Stark effect spectroscopy, we found that the active site of the enzyme ketosteroid isomerase (KSI) exerts an extremely large electric field onto the C=O chemical bond that undergoes a charge rearrangement in KSI's rate-determining step. Moreover, we found that the magnitude of the electric field exerted by the active site strongly correlates with the enzyme's catalytic rate enhancement, enabling us to quantify the fraction of the catalytic effect that is electrostatic in origin. The measurements described here may help explain the role of electrostatics in many other enzymes and biomolecular systems.
4. Twinning in fcc lattice creates low-coordinated catalytically active sites in porous gold.
Science.gov (United States)
Krajčí, Marian; Kameoka, Satoshi; Tsai, An-Pang
2016-08-28
We describe a new mechanism for creation of catalytically active sites in porous gold. Samples of porous gold prepared by de-alloying Al2Au exhibit a clear correlation between the catalytic reactivity towards CO oxidation and structural defects in the fcc lattice of Au. We have found that on the stepped {211} surfaces quite common twin boundary defects in the bulk structure of porous gold can form long close-packed rows of atoms with the coordination number CN = 6. DFT calculations confirm that on these low-coordinated Au sites dioxygen chemisorbs and CO oxidation can proceed via the Langmuir-Hinshelwood mechanism with the activation energy of 37 kJ/mol or via the CO-OO intermediate with the energy barrier of 19 kJ/mol. The existence of the twins in porous gold is stabilized by the surface energy.
5. Dynamics and Mechanism of Efficient DNA Repair Reviewed by Active-Site Mutants
Science.gov (United States)
Tan, Chuang; Liu, Zheyun; Li, Jiang; Guo, Xunmin; Wang, Lijuan; Zhong, Dongping
2010-06-01
Photolyases repair the UV-induced pyrimidine dimers in damage DNA via a photoreaction which includes a series of light-driven electron transfers between the two-electron-reduced flavin cofactor FADH^- and the dimer. We report here our systematic studies of the repair dynamics in E. coli photolyase with mutation of several active-site residues. With femtosecond resolution, we observed the significant change in the forward electron transfer from the excited FADH^- to the dimer and the back electron transfer from the repaired thymines by mutation of E274A, R226A, R342A, N378S and N378C. We also found that the mutation of E274A accelerates the bond-breaking of the thymine dimer. The dynamics changes are consistent with the quantum yield study of these mutants. These results suggest that the active-site residues play a significant role, structurally and chemically, in the DNA repair photocycle.
6. 78 FR 21352 - Update on Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites
Science.gov (United States)
2013-04-10
... on Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites AGENCY... reimbursement for cleanup work performed by licensees at eligible uranium and thorium processing sites in... licensees of eligible uranium and thorium processing sites. If licensees submit claims in FY 2013,...
7. Simulation of the Mechanism of Gas Sorption in a Metal–Organic Framework with Open Metal Sites: Molecular Hydrogen in PCN-61
KAUST Repository
Forrest, Katherine A.
2012-07-26
Grand canonical Monte Carlo (GCMC) simulations were performed to investigate hydrogen sorption in an rht-type metal-organic framework (MOF), PCN-61. The MOF was shown to have a large hydrogen uptake, and this was studied using three different hydrogen potentials, effective for bulk hydrogen, but of varying sophistication: a model that includes only repulsion/dispersion parameters, one augmented with charge-quadrupole interactions, and one supplemented with many-body polarization interactions. Calculated hydrogen uptake isotherms and isosteric heats of adsorption, Q st, were in quantitative agreement with experiment only for the model with explicit polarization. This success in reproducing empirical measurements suggests that modeling MOFs that have open metal sites is feasible, though it is often not considered to be well described via a classical potential function; here it is shown that such systems may be accurately described by explicitly including polarization effects in an otherwise traditional empirical potential. Decomposition of energy terms for the models revealed deviations between the electrostatic and polarizable results that are unexpected due to just the augmentation of the potential surface by the addition of induction. Charge-quadrupole and induction energetics were shown to have a synergistic interaction, with inclusion of the latter resulting in a significant increase in the former. Induction interactions strongly influence the structure of the sorbed hydrogen compared to the models lacking polarizability; sorbed hydrogen is a dipolar dense fluid in the MOF. This study demonstrates that many-body polarization makes a critical contribution to gas sorption structure and must be accounted for in modeling MOFs with polar interaction sites. © 2012 American Chemical Society.
8. Protein kinase A (PKA) phosphorylation of Na+/K+-ATPase opens intracellular C-terminal water pathway leading to third Na+-binding site in molecular dynamics simulations
DEFF Research Database (Denmark)
Poulsen, Hanne; Nissen, Poul; Mouritsen, Ole G.;
2012-01-01
Phosphorylation is one of the major mechanisms for posttranscriptional modification of proteins. The addition of a compact, negatively charged moiety to a protein can significantly change its function and localization by affecting its structure and interaction network. We have used all-atom Molec...... the effects of S936 phosphorylation. The results establish a structural association of S936 with the C-terminus of NKA and indicate that phosphorylation of S936 can modulate pumping activity by changing the accessibility to the ion-binding site....
9. Interaction of mining activities and aquatic environment: A review from Greek mine sites.
Science.gov (United States)
Vasileiou, Eleni; Kallioras, Andreas
2016-04-01
In Greece a significant amount of mineral and ore deposits have been recorded accompanied by large industrial interest and a long mining history. Today many active and/or abandoned mine sites are scattered within the country; while mining activities take place in different sites for exploiting various deposits (clay, limestone, slate, gypsum, kaolin, mixed sulphide ores (lead, zinc, olivine, pozzolan, quartz lignite, nickel, magnesite, aluminum, bauxite, gold, marbles etc). The most prominent recent ones are: (i) the lignite exploitation that is extended in the area of Ptolemais (Western Macedonia) and Megalopolis (Central Peloponnese); and (ii) the major bauxite deposits located in central Greece within the Parnassos-Ghiona geotectonic zone and on Euboea Island. In the latter area, significant ores of magnesite were exploited and mixed sulphide ores. Centuries of intensive mining exploitation and metallurgical treatment of lead-silver deposits in Greece, have also resulted in significant abandoned sites, such as the one in Lavrion. Mining activities in Lavrio, were initiated in ancient times and continued until the 1980s, resulting in the production of significant waste stockpiles deposited in the area, crucial for the local water resources. Ιn many mining sites, environmental pressures are also recorded after the mine closure to the aquatic environment, as the surface waters flow through waste dump areas and contaminated soils. This paper aims to the geospatial visualization of the mining activities in Greece, in connection to their negative (surface- and/or ground-water pollution; overpumping due to extensive dewatering practices) or positive (enhanced groundwater recharge; pit lakes, improvement of water budget in the catchment scale) impacts on local water resources.
10. Variation of (222)Rn activity concentration in soil gas at a site in Sapporo, Japan.
Science.gov (United States)
Fujiyoshi, Ryoko; Kinoshita, Moriyoshi; Sawamura, Sadashi
2005-09-01
Several factors controlling the soil radon level in the present site were found to be changing air-filled porosity caused by fluctuations in moisture content, differences between the atmospheric and soil temperatures as well as volumetric (226)Ra content of the soil. The radon activity increased significantly in early October, especially at point 1, possibly as a result of a magnitude 8.0 earthquake which occurred on September 26, 2003, with epicenter located offshore near Tokachi, Hokkaido.
11. Identification of the provenience of Majolica from sites in the Caribbean using neutron activation analysis
Energy Technology Data Exchange (ETDEWEB)
Olin, J.S.; Sayre, E.V.
1975-01-01
Tin-enamelled earthenware pottery from five early Spanish Colonial sites in the Dominican Republic and Venezuela were sampled and analyzed by neutron activation analysis in an attempt to determine whether these sherds had a common source. The tentative conclusion was that although several sources were indicated for the specimens analyzed the overall similarity in composition indicated that these sources were probably closely related. (JSR)
12. Structural insight into the active site of a Bombyx mori unclassified glutathione transferase.
Science.gov (United States)
Hossain, Md Tofazzal; Yamamoto, Kohji
2015-01-01
Glutathione transferases (GSTs) are major detoxification enzymes that play central roles in the defense against various environmental toxicants as well as oxidative stress. Here, we identify amino acid residues of an unclassified GST from Bombyx mori, bmGSTu-interacting glutathione (GSH). Site-directed mutagenesis of bmGSTu mutants indicated that amino acid residues Asp103, Ser162, and Ser166 contribute to catalytic activity.
13. Probing the putative active site of YjdL: an unusual proton-coupled oligopeptide transporter from E. coli.
Directory of Open Access Journals (Sweden)
Johanne Mørch Jensen
Full Text Available YjdL from E. coli is an unusual proton-coupled oligopeptide transporter (POT. Unlike prototypical POTs, dipeptides are preferred over tripeptides, in particular dipeptides with a positively charged C-terminal residue. To further understand this difference in peptide specificity, the sequences of YjdL and YdgR, a prototypical E. coli POT, were compared in light of the crystal structure of a POT from Shewanella oneidensis. Several residues found in the putative active site were mutated and the activities of the mutated variants were assessed in terms of substrate uptake assays, and changes in specificity in terms of uptake inhibition. Most strikingly, changing the YjdL specific Asp392 to the conserved Ser in YjdL obliterated the preference for a positively charged C-terminal residue. Based on this unique finding and previously published results indicating that the dipeptide N-terminus may interact with Glu388, a preliminary orientation model of a dipeptide in the YjdL cavity is presented. Single site mutations of particularly Ala281 and Trp278 support the presented orientation. A dipeptide bound in the cavity of YjdL appears to be oriented such that the N-terminal side chain protrudes into a sub pocket that opens towards the extracellular space. The C-terminal side chain faces in the opposite direction into a sub pocket that faces the cytoplasm. These data indicated a stabilizing effect on a bulky N-terminal residue by an Ala281Phe variant and on the dipeptide backbone by Trp278. In the presented orientation model, Tyr25 and Tyr58 both appear to be in proximity of the dipeptide backbone while Lys117 appears to be in proximity of the peptide C-terminus. Mutational studies of these conserved residues highlight their functional importance.
14. Discovery and characterization of non-ATP site inhibitors of the mitogen activated protein (MAP) kinases.
Science.gov (United States)
Comess, Kenneth M; Sun, Chaohong; Abad-Zapatero, Cele; Goedken, Eric R; Gum, Rebecca J; Borhani, David W; Argiriadi, Maria; Groebe, Duncan R; Jia, Yong; Clampit, Jill E; Haasch, Deanna L; Smith, Harriet T; Wang, Sanyi; Song, Danying; Coen, Michael L; Cloutier, Timothy E; Tang, Hua; Cheng, Xueheng; Quinn, Christopher; Liu, Bo; Xin, Zhili; Liu, Gang; Fry, Elizabeth H; Stoll, Vincent; Ng, Teresa I; Banach, David; Marcotte, Doug; Burns, David J; Calderwood, David J; Hajduk, Philip J
2011-03-18
Inhibition of protein kinases has validated therapeutic utility for cancer, with at least seven kinase inhibitor drugs on the market. Protein kinase inhibition also has significant potential for a variety of other diseases, including diabetes, pain, cognition, and chronic inflammatory and immunologic diseases. However, as the vast majority of current approaches to kinase inhibition target the highly conserved ATP-binding site, the use of kinase inhibitors in treating nononcology diseases may require great selectivity for the target kinase. As protein kinases are signal transducers that are involved in binding to a variety of other proteins, targeting alternative, less conserved sites on the protein may provide an avenue for greater selectivity. Here we report an affinity-based, high-throughput screening technique that allows nonbiased interrogation of small molecule libraries for binding to all exposed sites on a protein surface. This approach was used to screen both the c-Jun N-terminal protein kinase Jnk-1 (involved in insulin signaling) and p38α (involved in the formation of TNFα and other cytokines). In addition to canonical ATP-site ligands, compounds were identified that bind to novel allosteric sites. The nature, biological relevance, and mode of binding of these ligands were extensively characterized using two-dimensional (1)H/(13)C NMR spectroscopy, protein X-ray crystallography, surface plasmon resonance, and direct enzymatic activity and activation cascade assays. Jnk-1 and p38α both belong to the MAP kinase family, and the allosteric ligands for both targets bind similarly on a ledge of the protein surface exposed by the MAP insertion present in the CMGC family of protein kinases and distant from the active site. Medicinal chemistry studies resulted in an improved Jnk-1 ligand able to increase adiponectin secretion in human adipocytes and increase insulin-induced protein kinase PKB phosphorylation in human hepatocytes, in similar fashion to Jnk-1 si
15. Discovery and Characterization of Non-ATP Site Inhibitors of the Mitogen Activated Protein (MAP) Kinases
Energy Technology Data Exchange (ETDEWEB)
Comess, Kenneth M.; Sun, Chaohong; Abad-Zapatero, Cele; Goedken, Eric R.; Gum, Rebecca J.; Borhani, David W.; Argiriadi, Maria; Groebe, Duncan R.; Jia, Yong; Clampit, Jill E.; Haasch, Deanna L.; Smith, Harriet T.; Wang, Sanyi; Song, Danying; Coen, Michael L.; Cloutier, Timothy E.; Tang, Hua; Cheng, Xueheng; Quinn, Christopher; Liu, Bo; Xin, Zhili; Liu, Gang; Fry, Elizabeth H.; Stoll, Vincent; Ng, Teresa I.; Banach, David; Marcotte, Doug; Burns, David J.; Calderwood, David J.; Hajduk, Philip J. (Abbott)
2012-03-02
Inhibition of protein kinases has validated therapeutic utility for cancer, with at least seven kinase inhibitor drugs on the market. Protein kinase inhibition also has significant potential for a variety of other diseases, including diabetes, pain, cognition, and chronic inflammatory and immunologic diseases. However, as the vast majority of current approaches to kinase inhibition target the highly conserved ATP-binding site, the use of kinase inhibitors in treating nononcology diseases may require great selectivity for the target kinase. As protein kinases are signal transducers that are involved in binding to a variety of other proteins, targeting alternative, less conserved sites on the protein may provide an avenue for greater selectivity. Here we report an affinity-based, high-throughput screening technique that allows nonbiased interrogation of small molecule libraries for binding to all exposed sites on a protein surface. This approach was used to screen both the c-Jun N-terminal protein kinase Jnk-1 (involved in insulin signaling) and p38{alpha} (involved in the formation of TNF{alpha} and other cytokines). In addition to canonical ATP-site ligands, compounds were identified that bind to novel allosteric sites. The nature, biological relevance, and mode of binding of these ligands were extensively characterized using two-dimensional {sup 1}H/{sup 13}C NMR spectroscopy, protein X-ray crystallography, surface plasmon resonance, and direct enzymatic activity and activation cascade assays. Jnk-1 and p38{alpha} both belong to the MAP kinase family, and the allosteric ligands for both targets bind similarly on a ledge of the protein surface exposed by the MAP insertion present in the CMGC family of protein kinases and distant from the active site. Medicinal chemistry studies resulted in an improved Jnk-1 ligand able to increase adiponectin secretion in human adipocytes and increase insulin-induced protein kinase PKB phosphorylation in human hepatocytes, in
16. An active site homology model of phenylalanine ammonia-lyase from Petroselinum crispum.
Science.gov (United States)
Röther, Dagmar; Poppe, László; Morlock, Gaby; Viergutz, Sandra; Rétey, János
2002-06-01
The plant enzyme phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) shows homology to histidine ammonia-lyase (HAL) whose structure has been solved by X-ray crystallography. Based on amino-acid sequence alignment of the two enzymes, mutagenesis was performed on amino-acid residues that were identical or similar to the active site residues in HAL to gain insight into the importance of this residues in PAL for substrate binding or catalysis. We mutated the following amino-acid residues: S203, R354, Y110, Y351, N260, Q348, F400, Q488 and L138. Determination of the kinetic constants of the overexpressed and purified enzymes revealed that mutagenesis led in each case to diminished activity. Mutants S203A, R354A and Y351F showed a decrease in kcat by factors of 435, 130 and 235, respectively. Mutants F400A, Q488A and L138H showed a 345-, 615- and 14-fold lower kcat, respectively. The greatest loss of activity occurred in the PAL mutants N260A, Q348A and Y110F, which were 2700, 2370 and 75 000 times less active than wild-type PAL. To elucidate the possible function of the mutated amino-acid residues in PAL we built a homology model of PAL based on structural data of HAL and mutagenesis experiments with PAL. The homology model of PAL showed that the active site of PAL resembles the active site of HAL. This allowed us to propose possible roles for the corresponding residues in PAL catalysis.
17. Myelin 2',3'-cyclic nucleotide 3'-phosphodiesterase: active-site ligand binding and molecular conformation.
Directory of Open Access Journals (Sweden)
Matti Myllykoski
Full Text Available The 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase is a highly abundant membrane-associated enzyme in the myelin sheath of the vertebrate nervous system. CNPase is a member of the 2H phosphoesterase family and catalyzes the formation of 2'-nucleotide products from 2',3'-cyclic substrates; however, its physiological substrate and function remain unknown. It is likely that CNPase participates in RNA metabolism in the myelinating cell. We solved crystal structures of the phosphodiesterase domain of mouse CNPase, showing the binding mode of nucleotide ligands in the active site. The binding mode of the product 2'-AMP provides a detailed view of the reaction mechanism. Comparisons of CNPase crystal structures highlight flexible loops, which could play roles in substrate recognition; large differences in the active-site vicinity are observed when comparing more distant members of the 2H family. We also studied the full-length CNPase, showing its N-terminal domain is involved in RNA binding and dimerization. Our results provide a detailed picture of the CNPase active site during its catalytic cycle, and suggest a specific function for the previously uncharacterized N-terminal domain.
18. Photoreduction of the Active Site of the Metalloprotein Putidaredoxin By Synchrotron Radiation
Energy Technology Data Exchange (ETDEWEB)
Corbett, M.C.; /Stanford U., Chem. Dept.; Latimer, M.J.; Poulos, T.L.; Sevrioukova, I.F.; Hodgson, K.O.; /SLAC, SSRL /UC, Irvine /Stanford U., Chem. Dept. /SLAC, SSRL; Hedman, B.; /SLAC, SSRL
2007-10-10
X-ray damage to protein crystals is often assessed on the basis of the degradation of diffraction intensity, yet this measure is not sensitive to the rapid changes that occur at photosensitive groups such as the active sites of metalloproteins. Here, X-ray absorption spectroscopy is used to study the X-ray dose-dependent photoreduction of crystals of the [Fe2S2]-containing metalloprotein putidaredoxin. A dramatic decrease in the rate of photoreduction is observed in crystals cryocooled with liquid helium at 40 K compared with those cooled with liquid nitrogen at 110 K. Whereas structural changes consistent with cluster reduction occur in the active site of the crystal measured at 110 K, no such changes occur in the crystal measured at 40 K, even after an eightfold increase in dose. When the structural results from extended X-ray absorption fine-structure measurements are compared with those obtained by crystallography on this and similar proteins, it is apparent that X-ray-induced photoreduction has had an impact on the crystallographic data and subsequent structure solutions. These results strongly indicate the importance of using liquid-helium-based cooling for metalloprotein crystallography in order to avoid the subtle yet important changes that can take place at the metalloprotein active sites when liquid-nitrogen-based cooling is used. The study also illustrates the need for direct measurement of the redox states of the metals, through X-ray absorption spectroscopy, simultaneously with the crystallographic measurements.
19. Photoreduction of the active site of the metalloprotein putidaredoxin by synchrotron radiation.
Science.gov (United States)
Corbett, Mary C; Latimer, Matthew J; Poulos, Thomas L; Sevrioukova, Irina F; Hodgson, Keith O; Hedman, Britt
2007-09-01
X-ray damage to protein crystals is often assessed on the basis of the degradation of diffraction intensity, yet this measure is not sensitive to the rapid changes that occur at photosensitive groups such as the active sites of metalloproteins. Here, X-ray absorption spectroscopy is used to study the X-ray dose-dependent photoreduction of crystals of the [Fe(2)S(2)]-containing metalloprotein putidaredoxin. A dramatic decrease in the rate of photoreduction is observed in crystals cryocooled with liquid helium at 40 K compared with those cooled with liquid nitrogen at 110 K. Whereas structural changes consistent with cluster reduction occur in the active site of the crystal measured at 110 K, no such changes occur in the crystal measured at 40 K, even after an eightfold increase in dose. When the structural results from extended X-ray absorption fine-structure measurements are compared with those obtained by crystallography on this and similar proteins, it is apparent that X-ray-induced photoreduction has had an impact on the crystallographic data and subsequent structure solutions. These results strongly indicate the importance of using liquid-helium-based cooling for metalloprotein crystallography in order to avoid the subtle yet important changes that can take place at the metalloprotein active sites when liquid-nitrogen-based cooling is used. The study also illustrates the need for direct measurement of the redox states of the metals, through X-ray absorption spectroscopy, simultaneously with the crystallographic measurements.
20. Thermal regime of active layer at two lithologically contrasting sites on James Ross Island, Antarctic Peninsula.
Science.gov (United States)
Hrbáček, Filip; Nývlt, Daniel; Láska, Kamil
2016-04-01
Antarctic Peninsula region (AP) represents one of the most rapidly warming parts of our planet in the last 50 years. Despite increasing research activities along both western and eastern sides of AP in last decades, there is still a lot of gaps in our knowledge relating to permafrost, active layer and its thermal and physical properties. This study brings new results of active layer monitoring on James Ross Island, which is the largest island in northern AP. Its northern part, Ulu Peninsula, is the largest ice-free area (more than 200 km2) in the region. Due its large area, we focused this study on sites located in different lithologies, which would affect local thermal regime of active layer. Study site (1) at Abernethy Flats area (41 m a.s.l.) lies ~7 km from northern coast. Lithologically is formed by disintegrated Cretaceous calcareous sandstones and siltstones of the Santa Marta Formation. Study site (2) is located at the northern slopes of Berry Hill (56 m a.s.l.), about 0.4 km from northern coastline. Lithology is composed of muddy to intermediate diamictites, tuffaceous siltstones to fine grained sandstones of the Mendel Formation. Data of air temperature at 2 meters above ground and the active layer temperatures at 75 cm deep profiles were obtained from both sites in period 1 January 2012 to 31 December 2014. Small differences were found when comparing mean air temperatures and active temperatures at 5 and 75 cm depth in the period 2012-2014. While the mean air temperatures varied between -7.7 °C and -7.0 °C, the mean ground temperatures fluctuated between -6.6 °C and -6.1 °C at 5 cm and -6.9 °C and -6.0 °C at 75 cm at Abernethy Flats and Berry Hill slopes respectively. Even though ground temperature differences along the profiles weren't pronounced during thawing seasons, the maximum active layer thickness was significantly larger at Berry Hill slopes (80 to 82 cm) than at Abernethy Flats (52 to 64 cm). We assume this differences are affected by
1. Alkynol natural products target ALDH2 in cancer cells by irreversible binding to the active site.
Science.gov (United States)
Heydenreuter, Wolfgang; Kunold, Elena; Sieber, Stephan A
2015-11-11
Falcarinol and stipudiol are natural products with potent anti-cancer activity found in several vegetables. Here, we use a chemical proteomic strategy to identify ALDH2 as a molecular target of falcarinol in cancer cells and confirm enzyme inhibition via covalent alkylation of the active site. Furthermore, the synthesis of stipudiol led to the observation that ALDH2 exhibits preference for alkynol-based binders. Inhibition of ALDH2 impairs detoxification of reactive aldehydes and limits oxidative stress response, two crucial pathways for cellular viability.
2. NMR crystallography of enzyme active sites: probing chemically detailed, three-dimensional structure in tryptophan synthase.
Science.gov (United States)
Mueller, Leonard J; Dunn, Michael F
2013-09-17
NMR crystallography--the synergistic combination of X-ray diffraction, solid-state NMR spectroscopy, and computational chemistry--offers unprecedented insight into three-dimensional, chemically detailed structure. Initially, researchers used NMR crystallography to refine diffraction data from organic and inorganic solids. Now we are applying this technique to explore active sites in biomolecules, where it reveals chemically rich detail concerning the interactions between enzyme site residues and the reacting substrate. Researchers cannot achieve this level of detail from X-ray, NMR,or computational methodologies in isolation. For example, typical X-ray crystal structures (1.5-2.5 Å resolution) of enzyme-bound intermediates identify possible hydrogen-bonding interactions between site residues and substrate but do not directly identify the protonation states. Solid-state NMR can provide chemical shifts for selected atoms of enzyme-substrate complexes, but without a larger structural framework in which to interpret them only empirical correlations with local chemical structure are possible. Ab initio calculations and molecular mechanics can build models for enzymatic processes, but they rely on researcher-specified chemical details. Together, however, X-ray diffraction, solid-state NMR spectroscopy, and computational chemistry can provide consistent and testable models for structure and function of enzyme active sites: X-ray crystallography provides a coarse framework upon which scientists can develop models of the active site using computational chemistry; they can then distinguish these models by comparing calculated NMR chemical shifts with the results of solid-state NMR spectroscopy experiments. Conceptually, each technique is a puzzle piece offering a generous view of the big picture. Only when correctly pieced together, however, can they reveal the big picture at the highest possible resolution. In this Account, we detail our first steps in the development of
3. A novel mutation in the β-spectrin gene causes the activation of a cryptic 5'-splice site and the creation of a de novo 3'-splice site.
Science.gov (United States)
Salas, Pilar Carrasco; Rosales, José Miguel Lezana; Milla, Carmen Palma; Montiel, Javier López; Siles, Juan López
2015-01-01
The analysis of genes involved in hereditary spherocytosis, by next-generation sequencing in two patients with clinical diagnosis of the disease, showed the presence of the c.1795+1G>A mutation in the SPTB gene. cDNA amplification then revealed the occurrence of a consequent aberrant mRNA isoform produced from the activation of a cryptic 5'-splice site and the creation of a newly 3'-splice site. The mechanisms by which these two splice sites are used as a result of the same mutation should be analyzed in depth in further studies.
4. Design of Open Content Social Learning Based on the Activities of Learner and Similar Learners
Science.gov (United States)
John, Benneaser; Jayakumar, J.; Thavavel, V.; Arumugam, Muthukumar; Poornaselvan, K. J.
2017-01-01
Teaching and learning are increasingly taking advantage of the rapid growth in Internet resources, open content, mobile technologies and social media platforms. However, due to the generally unstructured nature and overwhelming quantity of learning content, effective learning remains challenging. In an effort to close this gap, the authors…
5. Influence of the International Academic and Labor Mobility on the Activity of Open Innovations
Science.gov (United States)
2016-01-01
This article presents the analysis of the new tendencies: openness of technologies, growth of the migration flows of the youth that are seeking for the quality education, and highly qualified professionals, who offer their unique abilities to large companies and research centers of the developed countries. The subjects of the world market…
6. IDENTIFICATION OF ACTIVE SITE RESIDUES IN DEXTRANSUCRASE FROM Weissella cibaria JAG8
Directory of Open Access Journals (Sweden)
Tingirikari Jagan Mohan Rao
2013-12-01
Full Text Available Dextransucrase isolated from Weissella cibaria JAG8 was subjected to chemical modification by bifunctional inhibitor o-phthalaldehyde to know the involvement of lysine and cysteine residues in its activity. The enzyme lost 97% of its activity in presence of 10 mM o-phthalaldehyde. The enzyme inhibitor complex gave absorbance maxima at 334 nm and fluorescence emission maxima at 418 nm, which confirmed the isoindole derivative formation. Sucrose protected the enzyme against o-phthalaldehyde inactivation. Denaturation with urea decreased the fluorescence emission showing that the native form of enzyme is essential for isoindole formation. Dextransucrase pre-treated with pyridoxal-5’-phosphate followed by o-phthalaldehyde treatment showed an increase in fluorescence intensity at 418 nm after dialysis, when compared with fluorescence intensity before dialysis, indicated that both the inhibitors bind to same lysine residues present at (or near the active site of enzyme. The results showed that both lysine and cysteine are the key amino acid residues which are present at the active site and are essential for dextransucrase activity.
7. A Robust Metal-Organic Framework Combining Open Metal Sites and Polar Groups for Methane Purification and CO2 /Fluorocarbon Capture.
Science.gov (United States)
Chen, Cheng-Xia; Zheng, Shao-Ping; Wei, Zhang-Wen; Cao, Chen-Chen; Wang, Hai-Ping; Wang, Dawei; Jiang, Ji-Jun; Fenske, Dieter; Su, Cheng-Yong
2017-03-23
A 3D porous perchlorinated metal-organic framework (MOF), LIFM-26, featuring dual functionality, that is, functional polar groups and open metal sites, has been synthesized using perchlorinated linear dicarboxylate to link trigonal prismatic Fe3 (μ3 -O) units. LIFM-26 exhibits good thermal and chemical stability, and possesses high porosity with a BET surface area of 1513 m(2) g(-1) , compared with isoreticular MOF-235 and Fe3 O(F4 BDC)3 (H2 O)3 (F4 BDC=2,3,5,6-tetrafluorobenzene-1,4-dicarboxylate). Most strikingly, LIFM-26 features good gas sorption/separation performance at 298 K and 1 atm with IAST selectivity values reaching up to 36, 93, 23, 11, 46, and 202 for CO2 /CH4 , CO2 /N2 , C2 H4 /CH4 , C2 H6 /CH4 , C3 H8 /CH4 , and R22/N2 (R22=CHClF2 ), respectively, showing potential for use in biogas/natural gas purification and CO2 /R22 capture. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
8. Open coordination sites-induced structural diversity of a new series of Cu(II) complexes with tridentate aroylhydrazone Schiff base
Science.gov (United States)
Xu, Guohong; Tang, Beibei; Gu, Leilei; Zhou, Pei; Li, Hui
2016-09-01
Six Cu(II) complexes containing the NO2 donor tridentate asymmetrical aroylhydrazone ligand (E)-4-hydroxy-N‧-((2-hydroxynaphthalen-1-yl)methylene)benzohydrazide (HL), namely, [Cu(L)Cl]·2H2O (1), [Cu(L)(CH3OH)2]·NO3 (2), [Cu(L)(NO3)(H2O)]·H2O (3), [Cu(L)(CH3OH)Cl]·CH3OH (4), [Cu(L)(SCN)(DMF)]·DMF (5) and {[Cu(L)(4,4‧-bipy)]ClO4·4DMF}n (6) have been synthesized and analysized by X-ray singal crystal diffraction. The structures of 1-6 are varied from zero-dimensional (0D) mononuclear complex to one-dimensional (1D) polymer based on the control of solvents, anions or auxiliary ligands, which can occupy the open coordination sites of Cu(II). Different hydrogen bonding interactions can also be observed in these complexes.
9. Three-dimensional representations of salt-dome margins at four active strategic petroleum reserve sites.
Energy Technology Data Exchange (ETDEWEB)
Rautman, Christopher Arthur; Stein, Joshua S.
2003-01-01
Existing paper-based site characterization models of salt domes at the four active U.S. Strategic Petroleum Reserve sites have been converted to digital format and visualized using modern computer software. The four sites are the Bayou Choctaw dome in Iberville Parish, Louisiana; the Big Hill dome in Jefferson County, Texas; the Bryan Mound dome in Brazoria County, Texas; and the West Hackberry dome in Cameron Parish, Louisiana. A new modeling algorithm has been developed to overcome limitations of many standard geological modeling software packages in order to deal with structurally overhanging salt margins that are typical of many salt domes. This algorithm, and the implementing computer program, make use of the existing interpretive modeling conducted manually using professional geological judgement and presented in two dimensions in the original site characterization reports as structure contour maps on the top of salt. The algorithm makes use of concepts of finite-element meshes of general engineering usage. Although the specific implementation of the algorithm described in this report and the resulting output files are tailored to the modeling and visualization software used to construct the figures contained herein, the algorithm itself is generic and other implementations and output formats are possible. The graphical visualizations of the salt domes at the four Strategic Petroleum Reserve sites are believed to be major improvements over the previously available two-dimensional representations of the domes via conventional geologic drawings (cross sections and contour maps). Additionally, the numerical mesh files produced by this modeling activity are available for import into and display by other software routines. The mesh data are not explicitly tabulated in this report; however an electronic version in simple ASCII format is included on a PC-based compact disk.
10. Influence of active sites organisation on calcium carbonate formation at model biomolecular interfaces
Science.gov (United States)
Hacke, S.; Möbius, D.; Lieu, V.-T.
2005-06-01
In an approach to understand the influence of structural parameters of interfaces on calcification in biomineralisation, the distribution and conformation of head groups as active sites in an inert matrix were varied using two-component phospholipid model monolayers. Dimyristoylphosphatidic acid (DMPA) and dipalmitoylphosphatidylcholin (DPPC), respectively, were the active components, and methyl octadecanoate (MOD) was used as inactive matrix. Surface pressure-area isotherms provide evidence for a different distribution of the active components in the matrix. Formation of solid calcium carbonate with two-component monolayers on subphases containing aqueous CaCO 3 was observed in situ by Brewster angle microscopy, where CaCO 3 domains appear bright. Striking differences in kinetics and extent of CaCO 3 formation are observed between monolayers containing dimyristoylphosphatidic acid and those containing dipalmitoylphosphatidylcholin. The presence of κ-carrageenan in the subphase as a further active component resulted in partial inhibition of CaCO 3 formation.
11. Effect of methylprednisolone on the oxidative burst activity, adhesion molecules and clinical outcome following open heart surgery
DEFF Research Database (Denmark)
Toft, P; Christiansen, K; Tønnesen, Else Kirstine
1997-01-01
on granulocytes and improve clinical outcome. Sixteen patients undergoing open heart surgery participated in the study. Eight were randomized to receive methylprednisolone (30 mg/kg intravenously) at the start of anaesthesia while eight patients served as a control group. The oxidative burst was measured flow...... and the control group regarding the expression of adhesion molecules or the oxidative burst activity. In the steroid group the fluid gain during extracorporeal circulation (ECC) was 683 ml (median) compared to 1488 ml in the control group. Steroids prevented hyperthermia in the postoperative period but did...... not improve the weaning from the ventilator or reduce the stay in the intensive-care unit. In conclusion, treatment with steroids prevented hyperthermia following open heart surgery with CPB and reduced capillary leak during ECC. Methylprednisolone, however, did not reduce the oxidative burst activity...
12. Role of Arginine-304 in the Diphosphate-Triggered Active Site Closure Mechanism of Trichodiene Synthase
Energy Technology Data Exchange (ETDEWEB)
Vedula,L.; Cane, D.; Christianson, D.
2005-01-01
The X-ray crystal structures of R304K trichodiene synthase and its complexes with inorganic pyrophosphate (PPi) and aza analogues of the bisabolyl carbocation intermediate are reported. The R304K substitution does not cause large changes in the overall structure in comparison with the wild-type enzyme. The complexes with (R)- and (S)-azabisabolenes and PPi bind three Mg2+ ions, and each undergoes a diphosphate-triggered conformational change that caps the active site cavity. This conformational change is only slightly attenuated compared to that of the wild-type enzyme complexed with Mg{sup 2+}{sub 3-}PP{sub i}, in which R304 donates hydrogen bonds to PP{sub i} and D101. In R304K trichodiene synthase, K304 does not engage in any hydrogen bond interactions in the unliganded state and it donates a hydrogen bond to only PP{sub i} in the complex with (R)-azabisabolene; K304 makes no hydrogen bond contacts in its complex with PP{sub i} and (S)-azabisabolene. Thus, although the R304-D101 hydrogen bond interaction stabilizes diphosphate-triggered active site closure, it is not required for Mg{sup 2+}{sub 3-}PP{sub i} binding. Nevertheless, since R304K trichodiene synthase generates aberrant cyclic terpenoids with a 5000-fold reduction in kcat/KM, it is clear that a properly formed R304-D101 hydrogen bond is required in the enzyme-substrate complex to stabilize the proper active site contour, which in turn facilitates cyclization of farnesyl diphosphate for the exclusive formation of trichodiene. Structural analysis of the R304K mutant and comparison with the monoterpene cyclase (+)-bornyl diphosphate synthase suggest that the significant loss in activity results from compromised activation of the PP{sub i} leaving group.
13. Implementation of Low Carbon Construction Activities in Order to Optimize Water Consumption on the Construction Site
Directory of Open Access Journals (Sweden)
Reza Esmaeilifar
2014-06-01
Full Text Available The number of law carbon construction project had increased tremendously across Malaysia over the recent years. In fact, there is no doubt on the necessity of development law carbon construction and benefits that have for the society, specifically for the construction companies. In order to make significant inroads into the low carbon construction practices, the industry needs to improve its energy usage and natural resources consumed in all its construction site activities. This study attempts to evaluate the sources of CO2 emission regarding water usage during construction project; secondly, to identify effective optimization method with regard to water usage in construction activities; and finally, to provide a plan of actions to minimize CO2 emissions during construction activities. SPSS version 20 was used to analyse the collected data. 385 questionnaires were distributed to the construction companies in Malaysia. The findings revealed that, despite the importance of low carbon construction, not many companies are serious enough to cut down their natural resource consumption. The particular phenomena, myriad of contractors and construction firms in Malaysia have not yet paid attention binding themselves to carbon construction and green building's constitution in general by contrast to common construction activity. The location of the site for water is the main way for the law carbon construction and has been highlighted as the main reason of ignorance of the current situation within the construction sector. Indeed, introducing optimization methods is vital for contractors and supervisors of the sites to be motivated regarding inequality on usage of water during construction project, which lead to carbon dioxide creation. In addition to optimization water consumption, monitoring the usage of water during construction activity can play as a main role.
14. Structural evolution of luciferase activity in Zophobas mealworm AMP/CoA-ligase (protoluciferase) through site-directed mutagenesis of the luciferin binding site.
Science.gov (United States)
Prado, R A; Barbosa, J A; Ohmiya, Y; Viviani, V R
2011-07-01
The structural origin and evolution of bioluminescent activity of beetle luciferases from AMP/CoA ligases remains a mystery. Previously we cloned the luciferase-like enzyme from Zophobas morio mealworm, a reasonable protoluciferase model that could shine light on this mystery. Kinetic characterization and studies with D- and L-luciferin and their adenylates showed that stereoselectivity constitutes a critical feature for the origin of luciferase activity in AMP/CoA ligases. Comparison of the primary structures and modeling studies of this protoluciferase and the three main families of beetle luciferases showed that the carboxylic acid substrate binding site of this enzyme is smaller and more hydrophobic than the luciferin binding site of beetle luciferases, showing several substitutions of otherwise conserved residues. Thus, here we performed a site-directed mutagenesis survey of the carboxylic binding site motifs of the protoluciferase by replacing their residues by the respective conserved ones found in beetle luciferases in order to identify the structural determinants of luciferase/oxygenase activity. Although most of the substitutions had negative impact on the luminescence activity of the protoluciferase, only the substitution I327T improved the luminescence activity, resulting in a broad and 15 nm blue-shifted luminescence spectrum. Such substitution indicates the importance of the loop motif 322YGMSEI327 (341YGLTETT347 in Photinus pyralis luciferase) for luciferase activity, and indicates a possible route for the evolution of bioluminescence function of beetle luciferases.
15. Active-Site Structure of Class IV Adenylyl Cyclase and Transphyletic Mechanism
Energy Technology Data Exchange (ETDEWEB)
D Gallagher; S Kim; H Robinson; P Reddy
2011-12-31
Adenylyl cyclases (ACs) belonging to three nonhomologous classes (II, III, and IV) have been structurally characterized, enabling a comparison of the mechanisms of cyclic adenosine 3',5'-monophosphate biosynthesis. We report the crystal structures of three active-site complexes for Yersinia pestis class IV AC (AC-IV) - two with substrate analogs and one with product. Mn{sup 2+} binds to all three phosphates, and to Glu12 and Glu136. Electropositive residues Lys14, Arg63, Lys76, Lys111, and Arg113 also form hydrogen bonds to phosphates. The conformation of the analogs is suitable for in-line nucleophilic attack by the ribose O3' on {alpha}-phosphate (distance {approx} 4 {angstrom}). In the product complex, a second Mn ion is observed to be coordinated to both ribose 2' oxygen and ribose 3' oxygen. Observation of both metal sites, together with kinetic measurements, provides strong support for a two-cation mechanism. Eleven active-site mutants were also made and kinetically characterized. These findings and comparisons with class II and class III enzymes enable a detailed transphyletic analysis of the AC mechanism. Consistent with its lack of coordination to purine, Y. pestis AC-IV cyclizes both ATP and GTP. As in other classes of AC, the ribose is loosely bound, and as in class III, no base appears to ionize the O3' nucleophile. Different syn/anti conformations suggest that the mechanism involves a conformational transition, and further evidence suggests a role for ribosyl pseudorotation. With resolutions of 1.6-1.7 {angstrom}, these are the most detailed active-site ligand complexes for any class of this ubiquitous signaling enzyme.
16. Dynamics of the active site architecture in plant-type ferredoxin-NADP(+) reductases catalytic complexes.
Science.gov (United States)
Sánchez-Azqueta, Ana; Catalano-Dupuy, Daniela L; López-Rivero, Arleth; Tondo, María Laura; Orellano, Elena G; Ceccarelli, Eduardo A; Medina, Milagros
2014-10-01
17. Probing the electrostatics of active site microenvironments along the catalytic cycle for Escherichia coli dihydrofolate reductase.
Science.gov (United States)
Liu, C Tony; Layfield, Joshua P; Stewart, Robert J; French, Jarrod B; Hanoian, Philip; Asbury, John B; Hammes-Schiffer, Sharon; Benkovic, Stephen J
2014-07-23
Electrostatic interactions play an important role in enzyme catalysis by guiding ligand binding and facilitating chemical reactions. These electrostatic interactions are modulated by conformational changes occurring over the catalytic cycle. Herein, the changes in active site electrostatic microenvironments are examined for all enzyme complexes along the catalytic cycle of Escherichia coli dihydrofolate reductase (ecDHFR) by incorporation of thiocyanate probes at two site-specific locations in the active site. The electrostatics and degree of hydration of the microenvironments surrounding the probes are investigated with spectroscopic techniques and mixed quantum mechanical/molecular mechanical (QM/MM) calculations. Changes in the electrostatic microenvironments along the catalytic environment lead to different nitrile (CN) vibrational stretching frequencies and (13)C NMR chemical shifts. These environmental changes arise from protein conformational rearrangements during catalysis. The QM/MM calculations reproduce the experimentally measured vibrational frequency shifts of the thiocyanate probes across the catalyzed hydride transfer step, which spans the closed and occluded conformations of the enzyme. Analysis of the molecular dynamics trajectories provides insight into the conformational changes occurring between these two states and the resulting changes in classical electrostatics and specific hydrogen-bonding interactions. The electric fields along the CN axes of the probes are decomposed into contributions from specific residues, ligands, and solvent molecules that make up the microenvironments around the probes. Moreover, calculation of the electric field along the hydride donor-acceptor axis, along with decomposition of this field into specific contributions, indicates that the cofactor and substrate, as well as the enzyme, impose a substantial electric field that facilitates hydride transfer. Overall, experimental and theoretical data provide evidence for
18. Active-Site Structure of Class IV Adenylyl Cyclase and Transphyletic Mechanism
Energy Technology Data Exchange (ETDEWEB)
Gallagher, D.T.; Robinson, H.; Kim, S.-K.; Reddy, P. T.
2011-01-21
Adenylyl cyclases (ACs) belonging to three nonhomologous classes (II, III, and IV) have been structurally characterized, enabling a comparison of the mechanisms of cyclic adenosine 3',5'-monophosphate biosynthesis. We report the crystal structures of three active-site complexes for Yersinia pestis class IV AC (AC-IV)-two with substrate analogs and one with product. Mn{sup 2+} binds to all three phosphates, and to Glu12 and Glu136. Electropositive residues Lys14, Arg63, Lys76, Lys111, and Arg113 also form hydrogen bonds to phosphates. The conformation of the analogs is suitable for in-line nucleophilic attack by the ribose O3' on {alpha}-phosphate (distance {approx} 4 {angstrom}). In the product complex, a second Mn ion is observed to be coordinated to both ribose 2' oxygen and ribose 3' oxygen. Observation of both metal sites, together with kinetic measurements, provides strong support for a two-cation mechanism. Eleven active-site mutants were also made and kinetically characterized. These findings and comparisons with class II and class III enzymes enable a detailed transphyletic analysis of the AC mechanism. Consistent with its lack of coordination to purine, Y. pestis AC-IV cyclizes both ATP and GTP. As in other classes of AC, the ribose is loosely bound, and as in class III, no base appears to ionize the O3' nucleophile. Different syn/anti conformations suggest that the mechanism involves a conformational transition, and further evidence suggests a role for ribosyl pseudorotation. With resolutions of 1.6-1.7 {angstrom}, these are the most detailed active-site ligand complexes for any class of this ubiquitous signaling enzyme.
19. Characterization of the interactions between the active site of a protein tyrosine kinase and a divalent metal activator
Directory of Open Access Journals (Sweden)
Ayrapetov Marina K
2005-11-01
Full Text Available Abstract Background Protein tyrosine kinases are important enzymes for cell signalling and key targets for anticancer drug discovery. The catalytic mechanisms of protein tyrosine kinase-catalysed phosphorylation are not fully understood. Protein tyrosine kinase Csk requires two Mg2+ cations for activity: one (M1 binds to ATP, and the other (M2 acts as an essential activator. Results Experiments in this communication characterize the interaction between M2 and Csk. Csk activity is sensitive to pH in the range of 6 to 7. Kinetic characterization indicates that the sensitivity is not due to altered substrate binding, but caused by the sensitivity of M2 binding to pH. Several residues in the active site with potential of binding M2 are mutated and the effect on metal activation studied. An active mutant of Asn319 is generated, and this mutation does not alter the metal binding characteristics. Mutations of Glu236 or Asp332 abolish the kinase activity, precluding a positive or negative conclusion on their role in M2 coordination. Finally, the ability of divalent metal cations to activate Csk correlates to a combination of ionic radius and the coordination number. Conclusion These studies demonstrate that M2 binding to Csk is sensitive to pH, which is mainly responsible for Csk activity change in the acidic arm of the pH response curve. They also demonstrate critical differences in the metal activator coordination sphere in protein tyrosine kinase Csk and a protein Ser/Thr kinase, the cAMP-dependent protein kinase. They shed light on the physical interactions between a protein tyrosine kinase and a divalent metal activator.
20. Covalent binding of the organophosphorus agent FP-biotin to tyrosine in eight proteins that have no active site serine
OpenAIRE
Grigoryan, Hasmik; Li, Bin; Anderson, Erica K.; Xue, Weihua; Nachon, Florian; Lockridge, Oksana; Schopfer, Lawrence M.
2009-01-01
Organophosphorus esters (OP) are known to bind covalently to the active site serine of enzymes in the serine hydrolase family. It was a surprise to find that proteins with no active site serine are also covalently modified by OP. The binding site in albumin, transferrin, and tubulin was identified as tyrosine. The goal of the present work was to determine whether binding to tyrosine is a general phenomenon. Fourteen proteins were treated with a biotin-tagged organophosphorus agent called FP-b...
1. The Open Science Grid
Energy Technology Data Exchange (ETDEWEB)
Pordes, Ruth; /Fermilab; Kramer, Bill; Olson, Doug; / /LBL, Berkeley; Livny, Miron; Roy, Alain; /Wisconsin U., Madison; Avery, Paul; /Florida U.; Blackburn, Kent; /Caltech; Wenaus, Torre; /Brookhaven; Wurthwein, Frank; /UC, San Diego; Gardner, Rob; Wilde, Mike; /Chicago U. /Indiana U.
2007-06-01
The Open Science Grid (OSG) provides a distributed facility where the Consortium members provide guaranteed and opportunistic access to shared computing and storage resources. OSG provides support for and evolution of the infrastructure through activities that cover operations, security, software, troubleshooting, addition of new capabilities, and support for existing and engagement with new communities. The OSG SciDAC-2 project provides specific activities to manage and evolve the distributed infrastructure and support its use. The innovative aspects of the project are the maintenance and performance of a collaborative (shared & common) petascale national facility over tens of autonomous computing sites, for many hundreds of users, transferring terabytes of data a day, executing tens of thousands of jobs a day, and providing robust and usable resources for scientific groups of all types and sizes. More information can be found at the OSG web site: www.opensciencegrid.org.
2. The Open Science Grid
CERN Document Server
Pordes, Ruth; Olson, Doug; Livny, Miron; Roy, Alain; Avery, Paul; Blackburn, Kent; Wenaus, Torre; Wuerthwein, Frank K.; Gardner, Rob; Wilde, Mike; Blatecky, Alan; McGee, John; Quick, Rob
2007-01-01
The Open Science Grid (OSG) provides a distributed facility where the Consortium members provide guaranteed and opportunistic access to shared computing and storage resources. OSG provides support for and evolution of the infrastructure through activities that cover operations, security, software, troubleshooting, addition of new capabilities, and support for existing and engagement with new communities. The OSG SciDAC-2 project provides specific activities to manage and evolve the distributed infrastructure and support it's use. The innovative aspects of the project are the maintenance and performance of a collaborative (shared & common) petascale national facility over tens of autonomous computing sites, for many hundreds of users, transferring terabytes of data a day, executing tens of thousands of jobs a day, and providing robust and usable resources for scientific groups of all types and sizes. More information can be found at the OSG web site: www.opensciencegrid.org.
3. The open science grid
Energy Technology Data Exchange (ETDEWEB)
Pordes, Ruth [Fermi National Accelerator Laboratory (United States); Petravick, Don [Fermi National Accelerator Laboratory (United States); Kramer, Bill [Lawrence Berkeley National Laboratory (United States); Olson, Doug [Lawrence Berkeley National Laboratory (United States); Livny, Miron [University of Wisconsin, Madison (United States); Roy, Alain [University of Wisconsin, Madison (United States); Avery, Paul [University of Florida (United States); Blackburn, Kent [California Institute of Technology (United States); Wenaus, Torre [Brookhaven National Laboratory (United States); Wuerthwein, Frank [University of California, San Diego (United States); Foster, Ian [University of Chicago (United States); Gardner, Rob [University of Chicago (United States); Wilde, Mike [University of Chicago (United States); Blatecky, Alan [Renaissance Computing Institute (United States); McGee, John [Renaissance Computing Institute (United States); Quick, Rob [Indiana University (United States)
2007-07-15
The Open Science Grid (OSG) provides a distributed facility where the Consortium members provide guaranteed and opportunistic access to shared computing and storage resources. OSG provides support for and evolution of the infrastructure through activities that cover operations, security, software, troubleshooting, addition of new capabilities, and support for existing and engagement with new communities. The OSG SciDAC-2 project provides specific activities to manage and evolve the distributed infrastructure and support it's use. The innovative aspects of the project are the maintenance and performance of a collaborative (shared and common) petascale national facility over tens of autonomous computing sites, for many hundreds of users, transferring terabytes of data a day, executing tens of thousands of jobs a day, and providing robust and usable resources for scientific groups of all types and sizes. More information can be found at the OSG web site: www.opensciencegrid.org.
4. Functional properties of the two redox-active sites in yeast protein disulphide isomerase in vitro and in vivo
DEFF Research Database (Denmark)
Westphal, V; Darby, N J; Winther, Jakob R.
1999-01-01
to that of human PDI, both in rearrangement and oxidation reactions. However, while the a domain active site of the human enzyme is more active than the a'-site, the reverse is the case for yPDI. This prompted us to set up an assay to investigate whether the situation would be different with a native yeast...
5. CO-dynamics in the active site of cytochrome c oxidase
Science.gov (United States)
Soloviov, Maksym; Meuwly, Markus
2014-04-01
The transfer of CO from heme a3 to the CuB site in Cytochrome c oxidase (CcO) after photolysis is studied using molecular dynamics simulations using an explicitly reactive, parametrized potential energy surface based on density functional theory calculations. After photodissociation from the heme-Fe, the CO ligand rebinds to the CuB site on the sub-picosecond time scale. Depending on the simulation protocol the characteristic time ranges from 260 fs to 380 fs which compares with an estimated 450 fs from experiment based on the analysis of the spectral changes as a function of time delay after the photodissociating pulse. Following photoexcitation ≈90% of the ligands are found to rebind to either the CuB (major component, 85%) or the heme-Fe (minor component, 2%) whereas about 10% remain in an unbound state. The infrared spectra of unbound CO in the active site is broad and featureless and no appreciable shift relative to gas-phase CO is found, which is in contrast to the situation in myoglobin. These observations explain why experimentally, unbound CO in the binuclear site of CcO has not been found as yet.
6. Single-site substitutions improve cold activity and increase thermostability of the dehairing alkaline protease (DHAP).
Science.gov (United States)
Zhao, Hong-Yan; Wu, Li-Ying; Liu, Gang; Feng, Hong
2016-12-01
To engineer dehairing alkaline protease (DHAP) variants to improve cold activity and increase thermostability so these variants are suitable for the leather processing industry. Based on previous studies with bacterial alkaline proteases, double-site mutations (W106K/V149I and W106K/M124L) were introduced into the DHAP from Bacillus pumilus. Compared with the wild-type DHAP hydrolytic activity, the double-site variant W106K/V149I showed an increase in specific hydrolytic activity at 15 °C by 2.3-fold toward casein in terms of hydrolytic rate and 2.7-fold toward the synthetic peptide AAPF-pN by means of kcat/Km value. The thermostability of the variant (W106K/V149I) was improved with the half-life at 60 and 70 °C increased by 2.7- and 5.0-fold, respectively, when compared with the thermostability of the wild-type DHAP. Conclusively, an increase in the cold activity and thermostability of a bacterial alkaline protease was achieved by protein engineering.
7. [Enhancing glutamate decarboxylase activity by site-directed mutagenesis: an insight from Ramachandran plot].
Science.gov (United States)
Ke, Piyu; Huang, Jun; Hu, Sheng; Zhao, Weirui; Lü, Changjiang; Yu, Kai; Lei, Yinlin; Wang, Jinbo; Mei, Lehe
2016-01-01
8. Effect of particle surface area on ice active site densities retrieved from droplet freezing spectra
Science.gov (United States)
Beydoun, Hassan; Polen, Michael; Sullivan, Ryan C.
2016-10-01
Heterogeneous ice nucleation remains one of the outstanding problems in cloud physics and atmospheric science. Experimental challenges in properly simulating particle-induced freezing processes under atmospherically relevant conditions have largely contributed to the absence of a well-established parameterization of immersion freezing properties. Here, we formulate an ice active, surface-site-based stochastic model of heterogeneous freezing with the unique feature of invoking a continuum assumption on the ice nucleating activity (contact angle) of an aerosol particle's surface that requires no assumptions about the size or number of active sites. The result is a particle-specific property g that defines a distribution of local ice nucleation rates. Upon integration, this yields a full freezing probability function for an ice nucleating particle. Current cold plate droplet freezing measurements provide a valuable and inexpensive resource for studying the freezing properties of many atmospheric aerosol systems. We apply our g framework to explain the observed dependence of the freezing temperature of droplets in a cold plate on the concentration of the particle species investigated. Normalizing to the total particle mass or surface area present to derive the commonly used ice nuclei active surface (INAS) density (ns) often cannot account for the effects of particle concentration, yet concentration is typically varied to span a wider measurable freezing temperature range. A method based on determining what is denoted an ice nucleating species' specific critical surface area is presented and explains the concentration dependence as a result of increasing the variability in ice nucleating active sites between droplets. By applying this method to experimental droplet freezing data from four different systems, we demonstrate its ability to interpret immersion freezing temperature spectra of droplets containing variable particle concentrations. It is shown that general
9. Nature of Copper Active Sites in CuZSM-5: Theory and Experiment
Directory of Open Access Journals (Sweden)
Pawel Kozyra
2002-04-01
Full Text Available Abstract: We report here a concise resume reporting the way of constructing the model of an active site composed of transition metal cation exchanged in zeolites. The main goal was to devise the model of CuZSM-5 capable of describing geometrical and electronic properties of metal sites and adsorption complexes with small molecules. The models were built up starting from simple ring structures encountered in ZSM-5 framework to fused rings’ model selected as the representative of α position for hosting the exchanged cation. Geometrical and electronic properties of the basal model, composed of the extended framework cluster with Cu+ or Cu2+ cation, and adsorption complexes with diatomic molecules were extracted from DFT calculations. The stress was put here on direct confirmation of structural changes on copper reduction/oxidation and adsorption. Electron donor/acceptor properties of the sites combined with electronic properties of adsorbed molecules led to the proposal for the mechanism of NO activation by Cu+ZSM-5: transfer of electrons from copper d orbitals to antibonding states of NO should cause large weakening of the bond, which was evidenced also by IR measurements.
10. Compensatory signals associated with the activation of human GC 5' splice sites.
Science.gov (United States)
Kralovicova, Jana; Hwang, Gyulin; Asplund, A Charlotta; Churbanov, Alexander; Smith, C I Edvard; Vorechovsky, Igor
2011-09-01
GC 5' splice sites (5'ss) are present in ∼1% of human introns, but factors promoting their efficient selection are poorly understood. Here, we describe a case of X-linked agammaglobulinemia resulting from a GC 5'ss activated by a mutation in BTK intron 3. This GC 5'ss was intrinsically weak, yet it was selected in >90% primary transcripts in the presence of a strong and intact natural GT counterpart. We show that efficient selection of this GC 5'ss required a high density of GAA/CAA-containing splicing enhancers in the exonized segment and was promoted by SR proteins 9G8, Tra2β and SC35. The GC 5'ss was efficiently inhibited by splice-switching oligonucleotides targeting either the GC 5'ss itself or the enhancer. Comprehensive analysis of natural GC-AG introns and previously reported pathogenic GC 5'ss showed that their efficient activation was facilitated by higher densities of splicing enhancers and lower densities of silencers than their GT 5'ss equivalents. Removal of the GC-AG introns was promoted to a minor extent by the splice-site strength of adjacent exons and inhibited by flanking Alu repeats, with the first downstream Alus located on average at a longer distance from the GC 5'ss than other transposable elements. These results provide new insights into the splicing code that governs selection of noncanonical splice sites.
11. Stress-induced enhancement of leukocyte trafficking into sites of surgery or immune activation
Science.gov (United States)
Viswanathan, Kavitha; Dhabhar, Firdaus S.
2005-04-01
Effective immunoprotection requires rapid recruitment of leukocytes into sites of surgery, wounding, infection, or vaccination. In contrast to immunosuppressive chronic stressors, short-term acute stressors have immunoenhancing effects. Here, we quantify leukocyte infiltration within a surgical sponge to elucidate the kinetics, magnitude, subpopulation, and chemoattractant specificity of an acute stress-induced increase in leukocyte trafficking to a site of immune activation. Mice acutely stressed before sponge implantation showed 200-300% higher neutrophil, macrophage, natural killer cell, and T cell infiltration than did nonstressed animals. We also quantified the effects of acute stress on lymphotactin- (LTN; a predominantly lymphocyte-specific chemokine), and TNF-- (a proinflammatory cytokine) stimulated leukocyte infiltration. An additional stress-induced increase in infiltration was observed for neutrophils, in response to TNF-, macrophages, in response to TNF- and LTN, and natural killer cells and T cells in response to LTN. These results show that acute stress initially increases trafficking of all major leukocyte subpopulations to a site of immune activation. Tissue damage-, antigen-, or pathogen-driven chemoattractants subsequently determine which subpopulations are recruited more vigorously. Such stress-induced increases in leukocyte trafficking may enhance immunoprotection during surgery, vaccination, or infection, but may also exacerbate immunopathology during inflammatory (cardiovascular disease or gingivitis) or autoimmune (psoriasis, arthritis, or multiple sclerosis) diseases. chemokine | psychophysiological stress | surgical sponge | wound healing | lymphotactin
12. The Mechanism by which 146-N-Glycan Affects the Active Site of Neuraminidase.
Directory of Open Access Journals (Sweden)
Pi Liu
Full Text Available One of the most conserved glycosylation sites of neuraminidase (NA is 146-N-glycan. This site is adjacent to the 150-cavity of NA, which is found within the active site and thought to be a target for rational drug development against the antiviral resistance of influenza. Here, through a total of 2.4 μs molecular dynamics (MD simulations, we demonstrated that 146-N-glycan can stabilize the conformation of the 150-loop that controls the volume of the 150-cavity. Moreover, with 146-N-glycan, our simulation result was more consistent with crystal structures of NAs than simulations conducted without glycans. Cluster analysis of the MD trajectories showed that 146-N-glycan adopted three distinct conformations: monomer-bridged, dimer-bridged and standing. Of these conformations, the dimer-bridged 146-N-glycan was the most stable one and contributed to stabilization of the 150-loop conformation. Furthermore, our simulation revealed that various standing conformations of 146-N-glycan could block the entrance of the binding pocket. This result was consistent with experimental data and explained the relatively low activity of inhibitors with flexible substituents toward the 150-cavity. Together, our results lead us to hypothesize that rigid and hydrophobic substituents could serve as better inhibitors targeting the 150-cavity.
13. Complement receptor 2-mediated targeting of complement inhibitors to sites of complement activation.
Science.gov (United States)
Song, Hongbin; He, Chun; Knaak, Christian; Guthridge, Joel M; Holers, V Michael; Tomlinson, Stephen
2003-06-01
In a strategy to specifically target complement inhibitors to sites of complement activation and disease, recombinant fusion proteins consisting of a complement inhibitor linked to a C3 binding region of complement receptor (CR) 2 were prepared and characterized. Natural ligands for CR2 are C3 breakdown products deposited at sites of complement activation. Fusion proteins were prepared consisting of a human CR2 fragment linked to either the N terminus or C terminus of soluble forms of the membrane complement inhibitors decay accelerating factor (DAF) or CD59. The targeted complement inhibitors bound to C3-opsonized cells, and all were significantly more effective (up to 20-fold) than corresponding untargeted inhibitors at protecting target cells from complement. CR2 fusion proteins also inhibited CR3-dependent adhesion of U937 cells to C3 opsonized erythrocytes, indicating a second potential anti-inflammatory mechanism of CR2 fusion proteins, since CR3 is involved in endothelial adhesion and diapedesis of leukocytes at inflammatory sites. Finally, the in vivo validity of the targeting strategy was confirmed by the demonstration that CR2-DAF, but not soluble DAF, targets to the kidney in mouse models of lupus nephritis that are associated with renal complement deposition.
14. Human glucocerebrosidase: heterologous expression of active site mutants in murine null cells.
Science.gov (United States)
Fabrega, S; Durand, P; Codogno, P; Bauvy, C; Delomenie, C; Henrissat, B; Martin, B M; McKinney, C; Ginns, E I; Mornon, J P; Lehn, P
2000-11-01
Using bioinformatics methods, we have previously identified Glu235 and Glu340 as the putative acid/base catalyst and nucleophile, respectively, in the active site of human glucocerebrosidase. Thus, we undertook site-directed mutagenesis studies to obtain experimental evidence supporting these predictions. Recombinant retroviruses were used to express wild-type and E235A and E340A mutant proteins in glucocerebrosidase-deficient murine cells. In contrast to wild-type enzyme, the mutants were found to be catalytically inactive. We also report the results of various studies (Western blotting, glycosylation analysis, subcellular fractionation, and confocal microscopy) indicating that the wild-type and mutant enzymes are identically processed and sorted to the lysosomes. Thus, enzymatic inactivity of the mutant proteins is not the result of incorrect folding/processing. These findings indicate that Glu235 plays a key role in the catalytic machinery of human glucocerebrosidase and may indeed be the acid/base catalyst. As concerns Glu340, the results both support our computer-based predictions and confirm, at the biological level, previous identification of Glu340 as the nucleophile by use of active site labeling techniques. Finally, our findings may help to better understand the molecular basis of Gaucher disease, the human lysosomal disease resulting from deficiency in glucocerebrosidase.
15. Revised description of index of Florida water data collection active stations and a user's guide for station or site information retrieval computer program FINDEX H578
Science.gov (United States)
Geiger, Linda H.
1983-01-01
The report is an update of U.S. Geological Survey Open-File Report 77-703, which described a retrieval program for administrative index of active data-collection sites in Florida. Extensive changes to the Findex system have been made since 1977 , making the previous report obsolete. A description of the data base and computer programs that are available in the Findex system are documented in this report. This system serves a vital need in the administration of the many and diverse water-data collection activities. District offices with extensive data-collection activities will benefit from the documentation of the system. Largely descriptive, the report tells how a file of computer card images has been established which contains entries for all sites in Florida at which there is currently a water-data collection activity. Entries include information such as identification number, station name, location, type of site, county, frequency of data collection, funding, and other pertinent details. The computer program FINDEX selectively retrieves entries and lists them in a format suitable for publication. The index is updated routinely. (USGS)
16. Comparison of body-powered voluntary opening and voluntary closing prehensor for activities of daily life
Directory of Open Access Journals (Sweden)
Kelsey Berning
2014-05-01
Full Text Available Persons with an upper-limb amputation who use a body-powered prosthesis typically control the prehensor through contralateral shoulder movement, which is transmitted through a Bowden cable. Increased cable tension either opens or closes the prehensor; when tension is released, some passive element, such as a spring, returns the prehensor to the default state (closed or open. In this study, we used the Southampton Hand Assessment Procedure to examine functional differences between these two types of prehensors in 29 nondisabled subjects (who used a body-powered bypass prosthesis and 2 persons with unilateral transradial amputations (who used a conventional body-powered device. We also administered a survey to determine whether subjects preferred one prehensor or the other for specific tasks, with a long-term goal of assessing whether a prehensor that could switch between both modes would be advantageous. We found that using the voluntary closing prehensor was 1.3 s faster (p = 0.02 than using the voluntary opening prehensor, across tasks, and that there was consensus among subjects on which types of tasks they preferred to do with each prehensor type. Twenty-five subjects wanted a device that could switch between the two modes in order to perform particular tasks.
17. Comparison of body-powered voluntary opening and voluntary closing prehensor for activities of daily life.
Science.gov (United States)
Berning, Kelsey; Cohick, Sarah; Johnson, Reva; Miller, Laura Ann; Sensinger, Jonathon W
2014-01-01
Persons with an upper-limb amputation who use a body-powered prosthesis typically control the prehensor through contralateral shoulder movement, which is transmitted through a Bowden cable. Increased cable tension either opens or closes the prehensor; when tension is released, some passive element, such as a spring, returns the prehensor to the default state (closed or open). In this study, we used the Southampton Hand Assessment Procedure to examine functional differences between these two types of prehensors in 29 nondisabled subjects (who used a body-powered bypass prosthesis) and 2 persons with unilateral transradial amputations (who used a conventional body-powered device). We also administered a survey to determine whether subjects preferred one prehensor or the other for specific tasks, with a long-term goal of assessing whether a prehensor that could switch between both modes would be advantageous. We found that using the voluntary closing prehensor was 1.3 s faster (p = 0.02) than using the voluntary opening prehensor, across tasks, and that there was consensus among subjects on which types of tasks they preferred to do with each prehensor type. Twenty-five subjects wanted a device that could switch between the two modes in order to perform particular tasks.
18. Benzodiazepines: rat pinealocyte binding sites and augmentation of norepinephrine-stimulated N-acetyltransferase activity
Energy Technology Data Exchange (ETDEWEB)
Matthew, E.; Parfitt, A.G.; Sugden, D.; Engelhardt, D.L.; Zimmerman, E.A.; Klein, D.C.
1984-02-01
Studies of (/sup 3/H)diazepam binding to intact rat pineal cells were carried out in tissue culture preparations. The binding was saturable, reversible and proportional to the number of cells used. Scatchard analysis resulted in a linear plot (Kd . 23 nM, maximum binding sites (Bmax) . 1.56 pmol/mg of protein for cells in monolayer culture; Kd . 7 nM, Bmax . 1.3 pmol/mg of protein for cells in suspension culture). Inhibition constants (Ki) for clonazepam (500 nM), flunitrazepam (38 nM) and Ro-5-4864 (5 nM) indicated that the binding sites were probably of the ''peripheral'' type. In addition, the effects of diazepam on norepinephrine-stimulated N-acetyltransferase (NAT) activity were studied in organ culture and dissociated cell culture. Diazepam (10-50 microM) both prolonged and increased the magnitude of the norepinephrine-induced increase in NAT activity but did not affect the initial rate of rise of enzyme activity. The effect was dose-dependent and was also seen with clonazepam, flunitrazepam and Ro-5-4864, but not with Ro-15-1788. Diazepam, by itself, at these concentrations, had no effect on NAT, but enzyme activity was increased by higher concentrations (0.1-1 mM). Although a relationship between the (/sup 3/H)diazepam binding sites described here and the effect of benzodiazepines on NAT cannot be established from these studies, the data suggest that the benzodiazepines may alter melatonin levels through their action on NAT.
19. Mechanical Control of ATP Synthase Function: Activation Energy Difference between Tight and Loose Binding Sites
KAUST Repository
Beke-Somfai, Tamás
2010-01-26
Despite exhaustive chemical and crystal structure studies, the mechanistic details of how FoF1-ATP synthase can convert mechanical energy to chemical, producing ATP, are still not fully understood. On the basis of quantum mechanical calculations using a recent highresolution X-ray structure, we conclude that formation of the P-O bond may be achieved through a transition state (TS) with a planar PO3 - ion. Surprisingly, there is a more than 40 kJ/mol difference between barrier heights of the loose and tight binding sites of the enzyme. This indicates that even a relatively small change in active site conformation, induced by the γ-subunit rotation, may effectively block the back reaction in βTP and, thus, promote ATP. © 2009 American Chemical Society.
20. The crystal structure of Pseudomonas putida azoreductase - the active site revisited.
Science.gov (United States)
Gonçalves, Ana Maria D; Mendes, Sónia; de Sanctis, Daniele; Martins, Lígia O; Bento, Isabel
2013-12-01
The enzymatic degradation of azo dyes begins with the reduction of the azo bond. In this article, we report the crystal structures of the native azoreductase from Pseudomonas putida MET94 (PpAzoR) (1.60 Å), of PpAzoR in complex with anthraquinone-2-sulfonate (1.50 Å), and of PpAzoR in complex with Reactive Black 5 dye (1.90 Å). These structures reveal the residues and subtle changes that accompany substrate binding and release. Such changes highlight the fine control of access to the catalytic site that is required by the ping-pong mechanism, and in turn the specificity offered by the enzyme towards different substrates. The topology surrounding the active site shows novel features of substrate recognition and binding that help to explain and differentiate the substrate specificity observed among different bacterial azoreductases.
1. Dipolar Relaxation Dynamics at the Active Site of an ATPase Regulated by Membrane Lateral Pressure.
Science.gov (United States)
Fischermeier, Elisabeth; Pospíšil, Petr; Sayed, Ahmed; Hof, Martin; Solioz, Marc; Fahmy, Karim
2017-01-24
The active transport of ions across biological membranes requires their hydration shell to interact with the interior of membrane proteins. However, the influence of the external lipid phase on internal dielectric dynamics is hard to access by experiment. Using the octahelical transmembrane architecture of the copper-transporting P1B -type ATPase from Legionella pneumophila as a model structure, we have established the site-specific labeling of internal cysteines with a polarity-sensitive fluorophore. This enabled dipolar relaxation studies in a solubilized form of the protein and in its lipid-embedded state in nanodiscs. Time-dependent fluorescence shifts revealed the site-specific hydration and dipole mobility around the conserved ion-binding motif. The spatial distribution of both features is shaped significantly and independently of each other by membrane lateral pressure. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
2. Evaluating the online activity of users of the e-Bug web site.
Science.gov (United States)
de Quincey, Ed; Kostkova, Patty; Jawaheer, Gawesh; Farrell, David; McNulty, Cliodna A M; Weinberg, Julius
2011-06-01
Web server log analysis is being increasingly used to evaluate the user behaviour on healthcare resource web sites due to the detailed record of activity that they contain. This study aimed to use this information to evaluate the e-Bug web site, a healthcare resource that provides a range of educational resources about microbes, hand and respiratory hygiene, and antibiotics. This evaluation was conducted by analysing the web server logs of the e-Bug web site for the period January 2008 to November 2009, using a proprietary application named Sawmill. The e-Bug web site has had >900,000 page views generated from >88,000 users, with an increase in May 2009 during the swine flu epidemic and a further increase in September 2009 following the official launch of e-Bug. The majority of visitors were from the UK, but visits were recorded from 190 different countries. Word(®) document resources were downloaded >169,000 times, with the most popular being a swine flu factsheet. PowerPoint(®) document resources were downloaded >36,000 times, with the most popular relating to the 'chain of infection'. The majority of visitor referrals originated from search engines, with the most popular referral keywords being variations on the e-Bug name. The most common non-search engine referrals were from other healthcare resources and agencies. Use of the site has increased markedly since the official launch of e-Bug, with average page views of >200,000 per month, from a range of countries, illustrating the international demand for a teaching resource for microbes, hygiene and antibiotics.
3. Exploring the active site structure of photoreceptor proteins by Raman optical activity
Science.gov (United States)
Unno, Masashi
2015-03-01
Understanding protein function at the atomic level is a major challenge in a field of biophysics and requires the combined efforts of structural and functional methods. We use photoreceptor proteins as a model system to understand in atomic detail how a chromophore and a protein interact to sense light and send a biological signal. A potential technique for investigating molecular structures is Raman optical activity (ROA), which is a spectroscopic method with a high sensitivity to the structural details of chiral molecules. However, its application to photoreceptor proteins has not been reported. Thus we have constructed ROA spectrometer using near-infrared (NIR) laser excitation at 785 nm. The NIR excitation enables us to measure ROA spectra for a variety of biological samples, including photoreceptor proteins, without fluorescence from the samples. In the present study, we have applied the NIR-ROA to bacteriorhodopsin (BR) and photoactive yellow protein (PYP). BR is a light-driven proton pump and contains a protonated Schiff base of retinal as a chromophore. PYP is a blue light receptor, and this protein has the 4-hydroxycinnamyl chromophore, which is covalently linked to Cys69 through a thiolester bond. We have successfully obtained the ROA spectra of the chromophore within a protein environment. Furthermore, calculations of the ROA spectra utilizing density functional theory provide detailed structural information, such as data on out-of-plane distortions of the chromophore. The structural information obtained from the ROA spectra includes the positions of hydrogen atoms, which are usually not detected in the crystal structures of biological samples.
4. Structural Basis for Substrate and Oxygen Activation in Homoprotocatechuate 2,3-Dioxygenase: Roles of Conserved Active Site Histidine-200
OpenAIRE
Kovaleva, Elena G.; Rogers, Melanie S.; Lipscomb, John D.
2015-01-01
Kinetic and spectroscopic studies have shown that the conserved active site residue His200 of the extradiol ring-cleaving homoprotocatechuate 2,3-dioxygenase (FeHPCD) from Brevibacterium fuscum is critical for efficient catalysis. The roles played by this residue are probed here by analysis of the steady state kinetics, pH dependence, and X-ray crystal structures of the FeHPCD position 200 variants His200Asn, His200Gln, and His200Glu alone and in complex with three catecholic substrates (homo...
5. Activities of the senspol and NICOLE network concerning field investigation at contaminated sites
Energy Technology Data Exchange (ETDEWEB)
Ree, C.C.D.F. von [GeoDelft, AB Delft (Netherlands); Alcock, S. [Cranfield Univ. of Silsoe, Bedfordshire (United Kingdom)
2003-07-01
At a European level several networks can be identified aimed at developments and exchange of knowledge relevant to sustainable management of the subsurface. Based on the common interests in the field of site characterisation and monitoring the SENSPOL and NICOLE networks have established links resulting in cooperation in several project-activities. In this presentation two projects will be addressed: - Seville technicalmeeting (Aznacollar mining site). - Bridging gaps between sensor developers and (end) users in a pragmatic approach (GAPS-project). The goal of the Seville technical meeting was to apply the latest sensing technologies at a site contaminated by metal mining activities, to properly evaluate the advances and limitations in the monitoring of contaminated sites for sustainable land management and to determine further steps to commercial exploitation. Some 17 different instruments have been brought including: - Electrochemical sensors using different forms of anodic stripping voltammetry and constant current chronopotentiometry combined with several types of screen printed electrodes. - An amperometric biosensor using screen printed electrodes, which measures toxicity by inhibition effects on urease and its sensitive to Hg(II), Ag(I), Cu(I) and to a lesser extent to Pb(II), Zn(II) and Cd(II) and a selectrochemical DNA biosensor measuring overall toxicity. - A luminescent bacterial sensors for measuring the bioavailable fraction of Cd, Pb, Zn, Cu, As, and Hg, and a bioluminescent fiber optic sensor for Hg and As. - Toxicity testing instruments (Checklight 'ToxScreen Multi-Shot Test, ToxAlert {sup registered} 100 and ToxAlert {sup registered} 10) - A fieldprobe for pH, EC, TDS measurement - A lead automatic analyser AQUAMET using a ion-selective electrode. - Pulse-neutron borehole device in which interaction of neutrons with the surrounding medium can be used to monitor changes. In a two-day field session on the mining site participants were provided
6. The complex structures of isocitrate dehydrogenase from Clostridium thermocellum and Desulfotalea psychrophila suggest a new active site locking mechanism.
Science.gov (United States)
Leiros, Hanna-Kirsti S; Fedøy, Anita-Elin; Leiros, Ingar; Steen, Ida Helene
2012-01-01
Isocitrate dehydrogenase (IDH) catalyzes the oxidative NAD(P)(+)-dependent decarboxylation of isocitrate into α-ketoglutarate and CO2 and is present in organisms spanning the biological range of temperature. We have solved two crystal structures of the thermophilic Clostridium thermocellum IDH (CtIDH), a native open apo CtIDH to 2.35 Å and a quaternary complex of CtIDH with NADP(+), isocitrate and Mg(2+) to 2.5 Å. To compare to these a quaternary complex structure of the psychrophilic Desulfotalea psychrophila IDH (DpIDH) was also resolved to 1.93 Å. CtIDH and DpIDH showed similar global thermal stabilities with melting temperatures of 67.9 and 66.9 °C, respectively. CtIDH represents a typical thermophilic enzyme, with a large number of ionic interactions and hydrogen bonds per residue combined with stabilization of the N and C termini. CtIDH had a higher activity temperature optimum, and showed greater affinity for the substrates with an active site that was less thermolabile compared to DpIDH. The uncompensated negative surface charge and the enlarged methionine cluster in the hinge region both of which are important for cold activity in DpIDH, were absent in CtIDH. These structural comparisons revealed that prokaryotic IDHs in subfamily II have a unique locking mechanism involving Arg310, Asp251' and Arg255 (CtIDH). These interactions lock the large domain to the small domain and direct NADP(+) into the correct orientation, which together are important for NADP(+) selectivity.
7. Protein function annotation with Structurally Aligned Local Sites of Activity (SALSAs
Directory of Open Access Journals (Sweden)
Wang Zhouxi
2013-02-01
Full Text Available Abstract Background The prediction of biochemical function from the 3D structure of a protein has proved to be much more difficult than was originally foreseen. A reliable method to test the likelihood of putative annotations and to predict function from structure would add tremendous value to structural genomics data. We report on a new method, Structurally Aligned Local Sites of Activity (SALSA, for the prediction of biochemical function based on a local structural match at the predicted catalytic or binding site. Results Implementation of the SALSA method is described. For the structural genomics protein PY01515 (PDB ID 2aqw from Plasmodium yoelii, it is shown that the putative annotation, Orotidine 5'-monophosphate decarboxylase (OMPDC, is most likely correct. SALSA analysis of YP_001304206.1 (PDB ID 3h3l, a putative sugar hydrolase from Parabacteroides distasonis, shows that its active site does not bear close resemblance to any previously characterized member of its superfamily, the Concanavalin A-like lectins/glucanases. It is noted that three residues in the active site of the thermophilic beta-1,4-xylanase from Nonomuraea flexuosa (PDB ID 1m4w, Y78, E87, and E176, overlap with POOL-predicted residues of similar type, Y168, D153, and E232, in YP_001304206.1. The substrate recognition regions of the two proteins are rather different, suggesting that YP_001304206.1 is a new functional type within the superfamily. A structural genomics protein from Mycobacterium avium (PDB ID 3q1t has been reported to be an enoyl-CoA hydratase (ECH, but SALSA analysis shows a poor match between the predicted residues for the SG protein and those of known ECHs. A better local structural match is obtained with Anabaena beta-diketone hydrolase (ABDH, a known β-diketone hydrolase from Cyanobacterium anabaena (PDB ID 2j5s. This suggests that the reported ECH function of the SG protein is incorrect and that it is more likely a β-diketone hydrolase. Conclusions
8. IN VITRO ANALYSIS OF τ PHOSPHORYLATION SITES AND ITS BIOLOGICAL ACTIVITY
Institute of Scientific and Technical Information of China (English)
2002-01-01
Objective.To explore the association between the abnormal phosphorylation sites found in Alzheimer disease (AD) τ and the inhibition of its biological activity. Methods.Ultracentrifugation,chromatography,manual Edman degradation and autosequence techniques were used to prepare and phosphorylate human recombinant τ ,isolate and purify 32P τ peptides and determine phosphorylation sites. Results.Phosphorylation of τ by casein kinase 1 (CK 1),cyclic AMP dependent protein kinase (PKA) and glycogen synthetase kinase 3 (GSK 3) separately inhibited its biological activity and the inhibition of this activity by GSK 3 was significantly increased if τ was prephosphorylated by CK 1 or PKA.The most potent inhibition was seen by a combined phosphorylation of τ with PKA and GSK 3.The treatment of τ by PKA and GSK 3 combination induced phosphorylation of τ at Ser 195,Ser 198,Ser 199,Ser 202,Thr 205,Thr 231,Ser 235,Ser 262,Ser 356,Ser 404,whereas Thr 181,Ser 184,Ser 262,Ser 356 and Ser 400 were phosphorylated by GSK 3 alone under the same condition. Conclusion.Phosphorylation of τ by PKA plus GSK 3 at Thr 205 might play a key role in τ pathology in AD.
9. The active site of oxidative phosphorylation and the origin of hyperhomocysteinemia in aging and dementia.
Science.gov (United States)
McCully, Kilmer S
2015-01-01
The active site of oxidative phosphorylation and adenosine triphosphate (ATP) synthesis in mitochondria is proposed to consist of two molecules of thioretinamide bound to cobalamin, forming thioretinaco, complexed with ozone, oxygen, nicotinamide adenine dinucleotide. and inorganic phosphate, TR2CoO3O2NAD(+)H2PO4(-). Reduction of the pyridinium nitrogen of the nicotinamide group by an electron from electron transport complexes initiates polymerization of phosphate with adenosine diphosphate, yielding nicotinamide riboside and ATP bound to thioretinaco ozonide oxygen. A second electron reduces oxygen to hydroperoxyl radical, releasing ATP from the active site. A proton gradient is created within F1F0 ATPase complexes of mitochondria by reaction of protons with reduced nicotinamide riboside and with hydroperoxyl radical, yielding reduced nicotinamide riboside and hydroperoxide. The hyperhomocysteinemia of aging and dementia is attributed to decreased synthesis of adenosyl methionine by thioretinaco ozonide and ATP, causing decreased allosteric activation of cystathionine synthase and decreased allosteric inhibition of methylenetetrahydrofolate reductase and resulting in dysregulation of methionine metabolism.
10. Active Edge Sites Engineering in Nickel Cobalt Selenide Solid Solutions for Highly Efficient Hydrogen Evolution
KAUST Repository
Xia, Chuan
2017-01-06
An effective multifaceted strategy is demonstrated to increase active edge site concentration in NiCoSe solid solutions prepared by in situ selenization process of nickel cobalt precursor. The simultaneous control of surface, phase, and morphology result in as-prepared ternary solid solution with extremely high electrochemically active surface area (C = 197 mF cm), suggesting significant exposure of active sites in this ternary compound. Coupled with metallic-like electrical conductivity and lower free energy for atomic hydrogen adsorption in NiCoSe, identified by temperature-dependent conductivities and density functional theory calculations, the authors have achieved unprecedented fast hydrogen evolution kinetics, approaching that of Pt. Specifically, the NiCoSe solid solutions show a low overpotential of 65 mV at -10 mV cm, with onset potential of mere 18 mV, an impressive small Tafel slope of 35 mV dec, and a large exchange current density of 184 μA cm in acidic electrolyte. Further, it is shown that the as-prepared NiCoSe solid solution not only works very well in acidic electrolyte but also delivers exceptional hydrogen evolution reaction (HER) performance in alkaline media. The outstanding HER performance makes this solid solution a promising candidate for mass hydrogen production.
11. Immediate restoration of NobelActive implants placed into fresh extraction sites in the anterior maxilla.
Science.gov (United States)
Bell, Christopher; Bell, Robert E
2014-08-01
The aim of this study is to compare the success rates of immediately placed and loaded NobelActive implants with the success rate of immediately placed implants that were allowed to osseointigrate prior to loading. The charts of all patients in a private oral surgery office receiving single-unit dental implants in the maxillary anterior region in fresh extraction sites from 2008-2011 were evaluated. All patients receiving NobelActive implants and immediate restorations were included in the study group, while those receiving implants with delayed restorations were included in the control group. Patient records were evaluated for variables such as age, gender, torque values at time of implant placement, smoking habits, use of bisphosphonates, and other significant diseases such as diabetes. The success rate of the study group was 92.9%, whereas the success rate of the control group was 97.6%. This was not statistically significant. Torque values of the failed implants of the study group were similar to those of successful implants in the study group. All implants placed in patients scheduled for immediate loading achieved high torque values and were able to be restored immediately. NobelActive implants were able to obtain high torque values for predictable immediate restoration in fresh extraction sites. Acceptable success rates with excellent soft tissue healing were achieved.
12. Prp4 Kinase Grants the License to Splice: Control of Weak Splice Sites during Spliceosome Activation.
Directory of Open Access Journals (Sweden)
Daniela Eckert
2016-01-01
Full Text Available The genome of the fission yeast Schizosaccharomyces pombe encodes 17 kinases that are essential for cell growth. These include the cell-cycle regulator Cdc2, as well as several kinases that coordinate cell growth, polarity, and morphogenesis during the cell cycle. In this study, we further characterized another of these essential kinases, Prp4, and showed that the splicing of many introns is dependent on Prp4 kinase activity. For detailed characterization, we chose the genes res1 and ppk8, each of which contains one intron of typical size and position. Splicing of the res1 intron was dependent on Prp4 kinase activity, whereas splicing of the ppk8 intron was not. Extensive mutational analyses of the 5' splice site of both genes revealed that proper transient interaction with the 5' end of snRNA U1 governs the dependence of splicing on Prp4 kinase activity. Proper transient interaction between the branch sequence and snRNA U2 was also important. Therefore, the Prp4 kinase is required for recognition and efficient splicing of introns displaying weak exon1/5' splice sites and weak branch sequences.
13. An open-path tunable diode laser absorption spectrometer for detection of carbon dioxide at the Bonanza Creek Long-Term Ecological Research Site near Fairbanks, Alaska
Science.gov (United States)
Bailey, D. Michelle; Adkins, Erin M.; Miller, J. Houston
2017-09-01
We have developed a low-power, open-path, near-infrared (NIR) tunable diode laser sensor for the measurement of near ground-level concentrations of greenhouse gases. Here, we report on instrument design, characterization, and initial measurements of carbon dioxide concentrations during deployment to a thermokarst collapse scar bog near Fairbanks, AK (USA). The optics "launch-box" portion of the instrument couples radiation from an NIR, distributed feedback diode laser operating near 1572 nm with a visible laser for alignment purposes. The outgoing beam is directed through a 3.2-mm hole in a parabolic mirror and the launch-box is oriented using a two axis, altitude-azimuth telescope mount such that the beam strikes a retroreflector target at a set distance downfield. The beam then retraces the path back to the launch-box where the light is collected on the surface of the parabolic mirror and focused onto a multimode fiber that transfers the radiation to an InGaAs detector. Sweeps over a 1.6 cm-1 spectral region were collected at a rate of 500 scans per second and were typically stored as 10 s sweep averages. These averaged sweeps could be individually spectrally fit for CO2 concentration or averaged into a single spectrum for fitting (after correction for slight frequency drift). Field data reported here was averaged for 2.5 min and was found to follow trends in diurnal cycles of CO2 concentration cycles reported by sensors located nearby in the field site.
14. In-situ electrochemically active surface area evaluation of an open-cathode polymer electrolyte membrane fuel cell stack
Science.gov (United States)
Torija, Sergio; Prieto-Sanchez, Laura; Ashton, Sean J.
2016-09-01
The ability to evaluate the electrochemically active surface area (ECSA) of fuel cell electrodes is crucial toward characterising designs and component suites in-situ, particularly when evaluating component durability in endurance testing, since it is a measure of the electrode area available to take part in the fuel cell reactions. Conventional methods to obtain the ECSA using cyclic voltammetry, however, rely on potentiostats that cannot be easily scaled to simultaneously evaluate all cells in a fuel cell stack of practical size, which is desirable in fuel cell development. In-situ diagnostics of an open-cathode fuel cell stack are furthermore challenging because the cells do not each possess an enclosed cathode compartment; instead, the cathodes are rather open to the environment. Here we report on a diagnostic setup that allows the electrochemically active surface area of each cell anode or cathode in an open-cathode fuel cell stack to be evaluated in-situ and simultaneously, with high resolution and reproducibility, using an easily scalable chronopotentiometry methodology and a gas-tight stack enclosure.
15. An important base triple anchors the substrate helix recognition surface within the Tetrahymena ribozyme active site.
Science.gov (United States)
Szewczak, A A; Ortoleva-Donnelly, L; Zivarts, M V; Oyelere, A K; Kazantsev, A V; Strobel, S A
1999-09-28
Key to understanding the structural biology of catalytic RNA is determining the underlying networks of interactions that stabilize RNA folding, substrate binding, and catalysis. Here we demonstrate the existence and functional importance of a Hoogsteen base triple (U300.A97-U277), which anchors the substrate helix recognition surface within the Tetrahymena group I ribozyme active site. Nucleotide analog interference suppression analysis of the interacting functional groups shows that the U300.A97-U277 triple forms part of a network of hydrogen bonds that connect the P3 helix, the J8/7 strand, and the P1 substrate helix. Product binding and substrate cleavage kinetics experiments performed on mutant ribozymes that lack this base triple (C A-U, U G-C) or replace it with the isomorphous C(+).G-C triple show that the A97 Hoogsteen triple contributes to the stabilization of both substrate helix docking and the conformation of the ribozyme's active site. The U300. A97-U277 base triple is not formed in the recently reported crystallographic model of a portion of the group I intron, despite the presence of J8/7 and P3 in the RNA construct [Golden, B. L., Gooding, A. R., Podell, E. R. & Cech, T. R. (1998) Science 282, 259-264]. This, along with other biochemical evidence, suggests that the active site in the crystallized form of the ribozyme is not fully preorganized and that substantial rearrangement may be required for substrate helix docking and catalysis.
16. Evaluation of stiffness and plastic deformation of active ceramic self-ligating bracket clips after repetitive opening and closure movements
Directory of Open Access Journals (Sweden)
Grace Kelly Martins Carneiro
2015-08-01
17. Crystallographic and Fluorescence Studies of the Interaction of Haloalkane Dehalogenase with Halide Ions. Studies with Halide Compounds Reveal a Halide Binding Site in the Active Site
NARCIS (Netherlands)
VERSCHUEREN, KHG; Kingma, Jacob; ROZEBOOM, HJ; KALK, KH; JANSSEN, DB; DIJKSTRA, BW
1993-01-01
Haloalkane dehalogenase from Xanthobacter autotrophicus GJ10 catalyzes the conversion of 1,2-dichloroethane to 2-chloroethanol and chloride without use of oxygen or cofactors. The active site is situated in an internal cavity, which is accesible from the solvent, even in the crystal. Crystal structu
18. Hanford Site implementation of the National Environmental Policy Act: Activities tracking
Energy Technology Data Exchange (ETDEWEB)
Killinger, M.H.; Selby, K.B.
1989-06-01
The National Environmental Policy Act (NEPA) environmental review process is mandatory for federal agencies. This report provides the DOE Richland Operations Office (DOE-RL) and the Hanford contractors with a method for tracking, integrating, and coordinating NEPA compliance activities at the Hanford Site. The environmental review process is briefly described and illustrated in a flow chart. The report then explains a method for developing project timecharts that show when documents or decision points were completed or are projected to be completed. The tracking system has been automated and placed on the Hanford Local Area Network (HLAN). Time schedules for many Hanford projects are available for viewing. 4 refs., 6 figs.
19. How to awaken your nanomachines: Site-specific activation of focal adhesion kinases through ligand interactions
KAUST Repository
Walkiewicz, Katarzyna Wiktoria
2015-06-17
The focal adhesion kinase (FAK) and the related protein-tyrosine kinase 2-beta (Pyk2) are highly versatile multidomain scaffolds central to cell adhesion, migration, and survival. Due to their key role in cancer metastasis, understanding and inhibiting their functions are important for the development of targeted therapy. Because FAK and Pyk2 are involved in many different cellular functions, designing drugs with partial and function-specific inhibitory effects would be desirable. Here, we summarise recent progress in understanding the structural mechanism of how the tug-of-war between intramolecular and intermolecular interactions allows these protein ‘nanomachines’ to become activated in a site-specific manner.
20. GTP plus water mimic ATP in the active site of protein kinase CK2
DEFF Research Database (Denmark)
Niefind, K; Pütter, M; Guerra, B
1999-01-01
The structures of the catalytic subunit of protein kinase CK2 from Zea mays complexed with Mg2+ and with analogs of ATP or GTP were determined to 2.2 A resolution. Unlike most other protein kinases, CK2 from various sources shows 'dual-cosubstrate specificity', that is, the ability to efficiently...... use either ATP or GTP as a cosubstrate. The structures of these complexes demonstrate that water molecules are critical to switch the active site of CK2 from an ATP- to a GTP-compatible state. An understanding of the structural basis of dual-cosubstrate specificity may help in the design of drugs...
1. Oxygen vacancies as active sites for water dissociation on rutile TiO2(110)
DEFF Research Database (Denmark)
Schaub, R.; Thostrup, P.; Lopez, Nuria
2001-01-01
Through an interplay between scanning tunneling microscopy experiments and density functional theory calculations, we determine unambiguously the active surface site responsible for the dissociation of water molecules adsorbed on rutile TiO2(110). Oxygen vacancies in the surface layer are shown...... to dissociate H2O through the transfer of one proton to a nearby oxygen atom, forming two hydroxyl groups for every vacancy. The amount of water dissociation is limited by the density of oxygen vacancies present on the clean surface exclusively. The dissociation process sets in as soon as molecular water...
2. Chemotactic Activity of Cyclophilin A in the Skin Mucus of Yellow Catfish (Pelteobagrus fulvidraco and Its Active Site for Chemotaxis
Directory of Open Access Journals (Sweden)
Farman Ullah Dawar
2016-08-01
Full Text Available Fish skin mucus is a dynamic barrier for invading pathogens with a variety of anti-microbial enzymes, including cyclophilin A (CypA, a multi-functional protein with peptidyl-prolyl cis/trans isomerase (PPIase activity. Beside various other immunological functions, CypA induces leucocytes migration in vitro in teleost. In the current study, we have discovered several novel immune-relevant proteins in yellow catfish skin mucus by mass spectrometry (MS. The CypA present among them was further detected by Western blot. Moreover, the CypA present in the skin mucus displayed strong chemotactic activity for yellow catfish leucocytes. Interestingly, asparagine (like arginine in mammals at position 69 was the critical site in yellow catfish CypA involved in leucocyte attraction. These novel efforts do not only highlight the enzymatic texture of skin mucus, but signify CypA to be targeted for anti-inflammatory therapeutics.
3. PCR-based site-specific mutagenesis of peptide antibiotics FALL-39 and its biologic activities
Institute of Scientific and Technical Information of China (English)
Yun-xia YANG; Yun FENG; Bo-yao WANG; Qi WU
2004-01-01
AIM: To construct PGEX-1λT-FALL-39 expression vector and its mutant vector, and study the relationship of function and structure. METHODS: A cDNA encoding mature FALL-39 was cloned from SPCA- 1 cell mRNA and the prokaryotic expression vector PGEX- 1λT-FALL-39 was constructed. Two kinds of polymerase chain reaction (PCR) for the site-direction mutagenesis were used to construct FALL-39 mutant expression vector, FALL-39-Lys-32 and FALL-39-Lys-24. Minimal effective concentration, minimal inhibitory concentration, and minimal bactericidal concentration were used to assay the antibacterial activities of these peptides. Effects of different solution on the antibacterial activity of FALL-39 and FALL-39-Lys-32 were observed by CFU determination. The hemolytic effects of these peptides were also examined on human red blood cells. RESULTS: Two site-specific mutants FALL-39-Lys-32 and FALL-39-Lys24 were obtained by PCR-induced mutagenesis. In comparison with two-step PCR which required two pairs of primers, one step PCR which required one pair of primers is a simple and efficient method for the PCR based site-specific mutagenesis. Using the prokaryotic expression system, the E coli-based products of recombinant FALL39 and its mutant peptides were also obtained. The antibacterial assay showed that FALL-39-Lys-32 and FALL-39-Lys24 were more potential in the antibacterial activity against E coli ML35p and Pseltdomonas aeruginosa ATCC27853 than that of FALL-39, and no increase in hemolysis was observed at the antibacterial concentrations. The antibacterial activity of FALL-39-Lys-32 against E coli was more potent than that of FALL-39 in NaCl-containing LB medium, while its activity was almost the same as FALL-39 in SO2-4 containing Medium E. CONCLUSION: PCR-based mutagensis is a useful model system for studying the structure and function relationship of antimicrobial peptides. Keeping α-helical conformation of FALL-39 and increasing net positive charge can increase the
4. Involvement of regions of the 4th and 7th chromosomes in the open-field activity of mice.
Science.gov (United States)
Clément, Y; Martin, B; Venault, P; Chapouthier, G
1995-09-01
Reactivity to a new environment was studied in mice, using an open-field procedure in two strains, C57BL/6By and ABP/Le, the F1 populations and the intercrosses F2 and backcross segregating populations. The analysis of the behavioral traits: peripheral and central activities, leaning, rearing and defecation in the parental strains made it possible to show that the ABP/Le strain was more reactive than C57BL/6By. In addition, the study of segregating, for four phenotypic markers, in F2 and backcross populations strongly suggested that two autosomal regions were involved in the control of open-field behavior: one in chromosomal region comprising the b locus on chromosome 4 and one in chromosomal region comprising the p locus on chromosome 7.
5. A binding site for activation by the Bacillus subtilis AhrC protein, a repressor/activator of arginine metabolism.
Science.gov (United States)
Klingel, U; Miller, C M; North, A K; Stockley, P G; Baumberg, S
1995-08-21
In Bacillus subtilis, the AhrC protein represses genes encoding enzymes of arginine biosynthesis and activates those mediating its catabolism. To determine how this repressor also functions as an activator, we attempted to clone catabolic genes by searching for insertions of the Tn917-lacZ transposon that express AhrC-dependent, arginine-inducible beta-galactosidase activity. One such isolate was obtained. The region upstream of lacZ was subcloned in Escherichia coli in such a way that it could be replaced in the B. subtilis chromosome after appropriate manipulation. Analysis of exonuclease III-derived deletions located an AhrC-dependent, arginine-inducible promoter to within a ca. 1.9 kb fragment. The sequence revealed: the 3' end of an ORF homologous to gdh genes encoding glutamate dehydrogenase, with highest homology to the homologue from Clostridium difficile; the 5' end of an ORF homologous to a Saccharomyces cerevisiae gene encoding delta 1-pyrroline 5-carboxylate dehydrogenase (P5CDH), an enzyme of arginine catabolism; and just upstream of the latter, a sequence with homology to known AhrC binding sites in the upstream part of the biosynthetic argCJBD-cpa-F cluster. The same region has also been sequenced by others as part of the B. subtilis genome sequencing project, revealing that the P5CDH gene is the first in a cluster termed rocABC. Restriction fragments containing the putative AhrC-binding sequence, but not those lacking it, showed retarded electrophoretic mobility in the presence of purified AhrC. A 277 bp AhrC-binding fragment also showed anomalous mobility in the absence of AhrC, consistent with its being intrinsically bent. DNAse I footprinting localized AhrC binding to bp -16/-22 to +1 (the transcription startpoint). Such a location for an activator binding site, i.e. overlapping the transcription start, is unusual.
6. The spectral analysis of motion: An "open field" activity test example
Directory of Open Access Journals (Sweden)
2013-01-01
Full Text Available In this work we have described the new mathematical approach, with spectral analysis of the data to evaluate position and motion in the „„open field““ experiments. The aim of this work is to introduce several new parameters mathematically derived from experimental data by means of spectral analysis, and to quantitatively estimate the quality of the motion. Two original software packages (TRACKER and POSTPROC were used for transforming a video data to a log file, suitable for further computational analysis, and to perform analysis from the log file. As an example, results obtained from the experiments with Wistar rats in the „open field“ test are included. The test group of animals was treated with diazepam. Our results demonstrate that all the calculated parameters, such as movement variability, acceleration and deceleration, were significantly lower in the test group compared to the control group. We believe that the application of parameters obtained by spectral analysis could be of great significance in assessing the locomotion impairment in any kind of motion. [Projekat Ministarstva nauke Republike Srbije, br. III41007 i br. ON174028
7. Function of the centromedial amygdala in reward devaluation and open-field activity.
Science.gov (United States)
Kawasaki, K; Glueck, A C; Annicchiarico, I; Papini, M R
2015-09-10
The present research aimed at determining the role played by the amygdala in reward devaluation using transient inactivation induced by lidocaine microinfusions into the centromedial region. Two situations involving reward devaluation were tested in rats: consummatory successive negative contrast (cSNC) and anticipatory negative contrast (ANC). In cSNC, rats exposed to a downshift from 32% to 4% sucrose consume less 4% sucrose than rats always exposed to 4% sucrose. Extensive evidence suggests that reward devaluation in the cSNC situation is accompanied by negative emotion. In ANC, rats consume less 4% sucrose when each session is closely followed by access to 32% sucrose rather than by 4% sucrose. Evidence suggests that reward devaluation in the ANC situation does not involve negative emotions; rather, ANC appears to involve Pavlovian anticipation of the higher value solution. To test the effects of lidocaine microinfusions in a situation known to induce negative emotion, but unrelated to reward devaluation, animals were also exposed to a lighted open field. Centromedial amygdala inactivation reduced the cSNC effect and increased exploratory behavior in the open field, both effects consistent with a reduction in negative emotional state. However, no detectable effects of amygdala inactivation were observed in the ANC situation. These results suggest that, first, the function of the amygdala is not unique to reward devaluation and, second, it is concerned with tagging the devaluation experience with aversive valence.
8. THE IMPLEMENTATION OF OPEN-INQUIRY APPROACH TO IMPROVE STUDENTS’ LEARNING ACTIVITIES, RESPONSES, AND MATHEMATICAL CREATIVE THINKING SKILLS
Directory of Open Access Journals (Sweden)
2016-12-01
Full Text Available This study aims to reveal the improvement of the students’ learning activities, responses, and mathematical creative thinking skills (MCTS through open- inquiry approach (OIA. Other relevant studies in mathematics learning tend to focus on guided inquiry, and especially in Indonesia, OIA is still less applied. This study is conducted at State Junior High School in Indonesia. The method used in this study is Classroom Action Research (CAR consists of four stages: planning, acting, observing, and reflecting. Data is collected through observation, journal reviews, interview, and test. The result of the study shows that the implementation of OIA enhances the students’ MCTS. It is shown by the improvement of the average of students’ score from 73.05 in the first cycle to 78.95 in the second cycle. The increasing of MCTS includes some aspects: fluency, flexibility, and originality. The result also shows that in general, the students give positive response and engage well in learning activities with OIA. It can be concluded that the implementation of OIA enhances learning activities, gives positive response towards mathematics, and improves students’ creative thinking skills. Keywords: Open-Inquiry Approach, Learning Activity, Response, Creative Thinking Skill DOI: http://dx.doi.org/10.22342/jme.8.1.3406.103-114
9. Analysis of active sites for N2 and H+ reduction on FeMocofactor of nitrogenase
Institute of Scientific and Technical Information of China (English)
GUAN Feng; ZHAO DeHua; PAN Miao; JIANG Wei; LI Jilun
2007-01-01
Dinitrogen (N2) and proton (H+), which act as physiological substrates of nitrogenase, are reduced on FeMo-co of the MoFe protein. However, researchers have different opinions about their exact reduction sites. Nitrogenases were purified from the wild type (WT) and five mutants of Azotobacter vinelandii (Av), including Qα191K, Hα195Q, nifV-, Qα191K/nifV- and Hα195Q/nifV-; and the activities of these enzymes for N2 and H+ reduction were analyzed. Our results suggest that the Fe2 and Fe6, atoms closed to the central sulfur atom (S2B) within FeMo-co, are sites for N2 binding and reduction and the Mo atom of FeMo-co is the site for H+ reduction. Combining these data with further bioinformatical analysis, we propose that two parallel electron channels may exist between the [8Fe7S] cluster and FeMo-co.
10. Relating subsurface temperature changes to microbial activity at a crude oil-contaminated site
Science.gov (United States)
Warren, Ean; Bekins, Barbara A.
2015-11-01
Crude oil at a spill site near Bemidji, Minnesota has been undergoing aerobic and anaerobic biodegradation for over 30 years, creating a 150-200 m plume of primary and secondary contaminants. Microbial degradation generates heat that should be measurable under the right conditions. To measure this heat, thermistors were installed in wells in the saturated zone and in water-filled monitoring tubes in the unsaturated zone. In the saturated zone, a thermal groundwater plume originates near the residual oil body with temperatures ranging from 2.9 °C above background near the oil to 1.2 °C down gradient. Temperatures in the unsaturated zone above the oil body were up to 2.7 °C more than background temperatures. Previous work at this site has shown that methane produced from biodegradation of the oil migrates upward and is oxidized in a methanotrophic zone midway between the water table and the surface. Enthalpy calculations and observations demonstrate that the temperature increases primarily result from aerobic methane oxidation in the unsaturated zone above the oil. Methane oxidation rates at the site independently estimated from surface CO2 efflux data are comparable to rates estimated from the observed temperature increases. The results indicate that temperature may be useful as a low-cost measure of activity but care is required to account for the correct heat-generating reactions, other heat sources and the effects of focused recharge.
11. Large lateral movement of transmembrane helix S5 is not required for substrate access to the active site of rhomboid intramembrane protease.
Science.gov (United States)
Xue, Yi; Ha, Ya
2013-06-07
Rhomboids represent an evolutionarily ancient protease family. Unlike most other proteases, they are polytopic membrane proteins and specialize in cleaving transmembrane protein substrates. The polar active site of rhomboid protease is embedded in the membrane and normally closed. For the bacterial rhomboid GlpG, it has been proposed that one of the transmembrane helices (S5) of the protease can rotate to open a lateral gate, enabling substrate to enter the protease from inside the membrane. Here, we studied the conformational change in GlpG by solving the cocrystal structure of the protease with a mechanism-based inhibitor. We also examined the lateral gating model by cross-linking S5 to a neighboring helix (S2). The crystal structure shows that inhibitor binding displaces a capping loop (L5) from the active site but causes only minor shifts in the transmembrane helices. Cross-linking S5 and S2, which not only restricts the lateral movement of S5 but also prevents substrate from passing between the two helices, does not hinder the ability of the protease to cleave a membrane protein substrate in detergent solution and in reconstituted membrane vesicles. Taken together, these data suggest that a large lateral movement of the S5 helix is not required for substrate access to the active site of rhomboid protease.
12. Dimensions of Openness
DEFF Research Database (Denmark)
Dalsgaard, Christian; Thestrup, Klaus
2015-01-01
as a matter of engaging educational activities in sociocultural practices of a surrounding society. Openness is not only a matter of opening up the existing, but of developing new educational practices that interact with society. The paper outlines three pedagogical dimensions of openness: transparency...... practices. Openness as joint engagement in the world aims at establishing interdependent collaborative relationships between educational institutions and external practices. To achieve these dimensions of openness, educational activities need to change and move beyond the course as the main format...... for openness. With examples from a university case, the paper discusses how alternative pedagogical formats and educational technologies can support the three dimensions of openness....
13. Active site detection by spatial conformity and electrostatic analysis--unravelling a proteolytic function in shrimp alkaline phosphatase.
Directory of Open Access Journals (Sweden)
Sandeep Chakraborty
Full Text Available Computational methods are increasingly gaining importance as an aid in identifying active sites. Mostly these methods tend to have structural information that supplement sequence conservation based analyses. Development of tools that compute electrostatic potentials has further improved our ability to better characterize the active site residues in proteins. We have described a computational methodology for detecting active sites based on structural and electrostatic conformity - CataLytic Active Site Prediction (CLASP. In our pipelined model, physical 3D signature of any particular enzymatic function as defined by its active sites is used to obtain spatially congruent matches. While previous work has revealed that catalytic residues have large pKa deviations from standard values, we show that for a given enzymatic activity, electrostatic potential difference (PD between analogous residue pairs in an active site taken from different proteins of the same family are similar. False positives in spatially congruent matches are further pruned by PD analysis where cognate pairs with large deviations are rejected. We first present the results of active site prediction by CLASP for two enzymatic activities - β-lactamases and serine proteases, two of the most extensively investigated enzymes. The results of CLASP analysis on motifs extracted from Catalytic Site Atlas (CSA are also presented in order to demonstrate its ability to accurately classify any protein, putative or otherwise, with known structure. The source code and database is made available at www.sanchak.com/clasp/. Subsequently, we probed alkaline phosphatases (AP, one of the well known promiscuous enzymes, for additional activities. Such a search has led us to predict a hitherto unknown function of shrimp alkaline phosphatase (SAP, where the protein acts as a protease. Finally, we present experimental evidence of the prediction by CLASP by showing that SAP indeed has protease activity in
14. Active site detection by spatial conformity and electrostatic analysis--unravelling a proteolytic function in shrimp alkaline phosphatase.
Science.gov (United States)
Chakraborty, Sandeep; Minda, Renu; Salaye, Lipika; Bhattacharjee, Swapan K; Rao, Basuthkar J
2011-01-01
Computational methods are increasingly gaining importance as an aid in identifying active sites. Mostly these methods tend to have structural information that supplement sequence conservation based analyses. Development of tools that compute electrostatic potentials has further improved our ability to better characterize the active site residues in proteins. We have described a computational methodology for detecting active sites based on structural and electrostatic conformity - CataLytic Active Site Prediction (CLASP). In our pipelined model, physical 3D signature of any particular enzymatic function as defined by its active sites is used to obtain spatially congruent matches. While previous work has revealed that catalytic residues have large pKa deviations from standard values, we show that for a given enzymatic activity, electrostatic potential difference (PD) between analogous residue pairs in an active site taken from different proteins of the same family are similar. False positives in spatially congruent matches are further pruned by PD analysis where cognate pairs with large deviations are rejected. We first present the results of active site prediction by CLASP for two enzymatic activities - β-lactamases and serine proteases, two of the most extensively investigated enzymes. The results of CLASP analysis on motifs extracted from Catalytic Site Atlas (CSA) are also presented in order to demonstrate its ability to accurately classify any protein, putative or otherwise, with known structure. The source code and database is made available at www.sanchak.com/clasp/. Subsequently, we probed alkaline phosphatases (AP), one of the well known promiscuous enzymes, for additional activities. Such a search has led us to predict a hitherto unknown function of shrimp alkaline phosphatase (SAP), where the protein acts as a protease. Finally, we present experimental evidence of the prediction by CLASP by showing that SAP indeed has protease activity in vitro.
15. Single-molecule catalysis mapping quantifies site-specific activity and uncovers radial activity gradient on single 2D nanocrystals.
Science.gov (United States)
Andoy, Nesha May; Zhou, Xiaochun; Choudhary, Eric; Shen, Hao; Liu, Guokun; Chen, Peng
2013-02-06
Shape-controlled metal nanocrystals are a new generation of nanoscale catalysts. Depending on their shapes, these nanocrystals exhibit various surface facets, and the assignments of their surface facets have routinely been used to rationalize or predict their catalytic activity in a variety of chemical transformations. Recently we discovered that for 1-dimensional (1D) nanocrystals (Au nanorods), the catalytic activity is not constant along the same side facets of single nanorods but rather differs significantly and further shows a gradient along its length, which we attributed to an underlying gradient of surface defect density resulting from their linear decay in growth rate during synthesis (Nat. Nanotechnol.2012, 7, 237-241). Here we report that this behavior also extends to 2D nanocrystals, even for a different catalytic reaction. By using super-resolution fluorescence microscopy to map out the locations of catalytic events within individual triangular and hexagonal Au nanoplates in correlation with scanning electron microscopy, we find that the catalytic activity within the flat {111} surface facet of a Au nanoplate exhibits a 2D radial gradient from the center toward the edges. We propose that this activity gradient results from a growth-dependent surface defect distribution. We also quantify the site-specific activity at different regions within a nanoplate: The corner regions have the highest activity, followed by the edge regions and then the flat surface facets. These discoveries highlight the spatial complexity of catalytic activity at the nanoscale as well as the interplay amid nanocrystal growth, morphology, and surface defects in determining nanocatalyst properties.
16. A comparative structure-function analysis of active-site inhibitors of Vibrio cholerae cholix toxin.
Science.gov (United States)
Lugo, Miguel R; Merrill, A Rod
2015-09-01
Cholix toxin from Vibrio cholerae is a novel mono-ADP-ribosyltransferase (mART) toxin that shares structural and functional properties with Pseudomonas aeruginosa exotoxin A and Corynebacterium diphtheriae diphtheria toxin. Herein, we have used the high-resolution X-ray structure of full-length cholix toxin in the apo form, NAD(+) bound, and 10 structures of the cholix catalytic domain (C-domain) complexed with several strong inhibitors of toxin enzyme activity (NAP, PJ34, and the P-series) to study the binding mode of the ligands. A pharmacophore model based on the active pose of NAD(+) was compared with the active conformation of the inhibitors, which revealed a cationic feature in the side chain of the inhibitors that may determine the active pose. Moreover, a conformational search was conducted for the missing coordinates of one of the main active-site loops (R-loop). The resulting structural models were used to evaluate the interaction energies and for 3D-QSAR modeling. Implications for a rational drug design approach for mART toxins were derived.
17. Disturbances in the circadian pattern of activity and sleep after laparoscopic versus open abdominal surgery
DEFF Research Database (Denmark)
Gögenur, Ismail; Bisgaard, Thue; Burgdorf, Stefan
2008-01-01
scale (sleep quality, general well-being and pain) and fatigue was measured by a ten-point fatigue scale. The activity levels of the patients were monitored by actigraphy (a wrist-worn device measuring patient activity). Measures of circadian activity level [interday stability (IS), intraday variability......BACKGROUND: Studies on the circadian variation in bodily functions and sleep are important for understanding the pathophysiological processes in the postoperative period. We aimed to investigate changes in the circadian variation in activity after minimally invasive surgery (laparoscopic...
18. Active site similarity between human and Plasmodium falciparum phosphodiesterases: considerations for antimalarial drug design
Science.gov (United States)
Howard, Brittany L.; Thompson, Philip E.; Manallack, David T.
2011-08-01
The similarity between Plasmodium falciparum phosphodiesterase enzymes ( PfPDEs) and their human counterparts have been examined and human PDE9A was found to be a suitable template for the construction of homology models for each of the four PfPDE isoforms. In contrast, the architecture of the active sites of each model was most similar to human PDE1. Molecular docking was able to model cyclic guanosine monophosphate (cGMP) substrate binding in each case but a docking mode supporting cyclic adenosine monophosphate (cAMP) binding could not be found. Anticipating the potential of PfPDE inhibitors as anti-malarial drugs, a range of reported PDE inhibitors including zaprinast and sildenafil were docked into the model of PfPDEα. The results were consistent with their reported biological activities, and the potential of PDE1/9 inhibitor analogues was also supported by docking.
19. A Tale of Two Emergences: Sunrise II Observations of Emergence Sites in a Solar Active Region
CERN Document Server
Centeno, Rebecca; Iniesta, Jose Carlos Del Toro; Solanki, Sami K; Barthol, Peter; Gandorfer, Achim; Gizon, Laurent; Hirzberger, Johann; Riethmuller, Tino L; van Noort, Michiel; Suarez, David Orozco; Schmidt, Wolfgang; Pillet, Valentin Martinez; Knolker, Michael
2016-01-01
In June 2013, the two scientific instruments onboard the second Sunrise mission witnessed, in detail, a small-scale magnetic flux emergence event as part of the birth of an active region. The Imaging Magnetograph Experiment (IMaX) recorded two small (~5 arcsec) emerging flux patches in the polarized filtergrams of a photospheric Fe I spectral line. Meanwhile, the Sunrise Filter Imager (SuFI) captured the highly dynamic chromospheric response to the magnetic fields pushing their way through the lower solar atmosphere. The serendipitous capture of this event offers a closer look at the inner workings of active region emergence sites. In particular, it reveals in meticulous detail how the rising magnetic fields interact with the granulation as they push through the Sun's surface, dragging photospheric plasma in their upward travel. The plasma that is burdening the rising field slides along the field lines, creating fast downflowing channels at the footpoints. The weight of this material anchors this field to the...
20. A site-specific curated database for the microorganisms of activated sludge and anaerobic digesters
DEFF Research Database (Denmark)
McIlroy, Simon Jon; Kirkegaard, Rasmus Hansen; McIlroy, Bianca
the composition and dynamics of the most abundant organisms. However, to understand the relationship between the population dynamics and operational parameters of the system, a functional role must be attributed to each organism. The Microbial Database for Activated Sludge (MiDAS) and Anaerobic Digesters (AD......) presented here provides a site specific curated taxonomy for abundant and important microorganisms and integrates it into a community knowledge web platform about the microbes in activated sludge (AS) and their associated ADs (www.midasfieldguide.org). The MiDAS taxonomy, a manual curation of the SILVA......, to improve the classification of unknown organisms and link these names to the wealth of present and future functional information about their ecology....
1. Water molecule network and active site flexibility of apo protein tyrosine phosphatase 1B
DEFF Research Database (Denmark)
Pedersen, A.K.; Peters, Günther H.J.; Møller, K.B.;
2004-01-01
Protein tyrosine phosphatase 1B (PTP1B) plays a key role as a negative regulator of insulin and leptin signalling and is therefore considered to be an important molecular target for the treatment of type 2 diabetes and obesity. Detailed structural information about the structure of PTP1B, including...... the conformation and flexibility of active-site residues as well as the water-molecule network, is a key issue in understanding ligand binding and enzyme kinetics and in structure-based drug design. A 1.95 Angstrom apo PTP1B structure has been obtained, showing four highly coordinated water molecules in the active...... of PTP1B and form a novel basis for structure-based inhibitor design....
2. Effect of ELF e.m. fields on metalloprotein redox-active sites
CERN Document Server
De Ninno, A; Ferrari, V; Gerardi, G; Barbaro, F; Badon, T; Bernardini, D
2008-01-01
The peculiarity of the distribution and geometry of metallic ions in enzymes pushed us to set the hypothesis that metallic ions in active-site act like tiny antennas able to pick up very feeble e.m. signals. Enzymatic activity of Cu2+, Zn2+ Superoxide Dismutase (SOD1) and Fe2+ Xanthine Oxidase (XO) has been studied, following in vitro generation and removal of free radicals. We observed that Superoxide radicals generation by XO is increased by a weak field having the Larmor frequency fL of Fe2+ while the SOD1 kinetics is sensibly reduced by exposure to a weak field having the frequency fL of Cu2+ ion.
3. Regulation of active site coupling in glutamine-dependent NAD[superscript +] synthetase
Energy Technology Data Exchange (ETDEWEB)
LaRonde-LeBlanc, Nicole; Resto, Melissa; Gerratana, Barbara; (Maryland)
2009-05-21
NAD{sup +} is an essential metabolite both as a cofactor in energy metabolism and redox homeostasis and as a regulator of cellular processes. In contrast to humans, Mycobacterium tuberculosis NAD{sup +} biosynthesis is absolutely dependent on the activity of a multifunctional glutamine-dependent NAD{sup +} synthetase, which catalyzes the ATP-dependent formation of NAD{sup +} at the synthetase domain using ammonia derived from L-glutamine in the glutaminase domain. Here we report the kinetics and structural characterization of M. tuberculosis NAD{sup +} synthetase. The kinetics data strongly suggest tightly coupled regulation of the catalytic activities. The structure, the first of a glutamine-dependent NAD{sup +} synthetase, reveals a homooctameric subunit organization suggesting a tight dependence of catalysis on the quaternary structure, a 40-{angstrom} intersubunit ammonia tunnel and structural elements that may be involved in the transfer of information between catalytic sites.
4. Effect of light-dark changes on the locomotor activity in open field in adult rats and opossums.
Science.gov (United States)
Klejbor, I; Ludkiewicz, B; Turlejski, K
2013-11-01
There have been no reports on how the light-dark changes determine the locomotor activity of animals in the group of high reactivity (HR) and low reactivity (LR). In the present study we have compared selected parameters of the locomotor activity of the HR and the LR groups of the laboratory opossums and Wistar rats during consecutive, light and dark phases in the open field test. Sixty male Wistar adult rats, at an average weight of 350 g each, and 24 adult Monodelphis opossums of both sexes at an average weight of 120 g each were used. The animals' activity for 2 h daily between the hours of 17:30 and 19:30, in line with the natural light-dark cycle were recorded and then analysed using VideoTrack ver.2.0 (Vievpoint France). According to our results, we noted that a change of the experimental conditions from light to dark involves an increase in the locomotor activity in rats and opossums of the HR group, while there is no effect on the activity of the rats and opossums in the LR group. Locomotor activity in the HR rats, both in the light and dark conditions is characterised by a consistent pattern of change - higher activity in the first stage of the recording and a slowdown (habituation) in the second phase of the observation. The locomotor activity of the opossum, during both light and dark conditions, was observed to be at a consistently high level compared to the rats.
5. Conformational changes of active site of copper zinc superoxide dismutase can be detected sensitively by electron-transfer reaction
Institute of Scientific and Technical Information of China (English)
舒占永
1996-01-01
The electron-transfer (ET) reaction between Fe(CN)64- and copper zinc superoxide dismutase (CuZn-SOD) occurs at the active site of the enzyme. The ET parameters which are sensitive to the denaturation have been used to determine the conformational changes of the active site induced by guanidine hydrochloride and thermal denaturation. The decreases of ET rates for all the denatured enzyme samples reflect the collapse of the active cavity of enzyme in the unfolding processes. The interesting changes of ET amplitude for the enzyme denatured at different pH values suggest that electrostatic interaction plays an important role in the conformational changes of active site. From the results of the kinetic analyses, it is concluded that the conformational changes of the active site are parallel with the inactivation.
6. Synthesis, characterization and catalytic activity of Ag-acidfuchsin nanohybrid system towards the ring opening polymerization of ε-caprolactone.
Science.gov (United States)
Meenarathi, B; Palanikumar, S; Kannammal, L; Anbarasan, R
2015-01-25
The acidfuchsin (AF) decorated Ag nanoparticle (NP) was synthesized and its ability towards the ring opening polymerization (ROP) of ε-caprolactone (CL) was studied under N2 atmosphere at 160 °C in the presence of stannous octoate (SO) as a catalyst. Both the nanohybrid and nanocomposites were characterized by various analytical tools like Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, fluorescence spectroscopy, gel permeation chromatography (GPC), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The number of binding site from the fluorescence spectrum confirmed that all the functional groups present in AF might have been involved in the ROP of CL. Copyright © 2014 Elsevier B.V. All rights reserved.
7. AMP-activated protein kinase phosphorylates EMCV, TMEV and SafV leader proteins at different sites.
Science.gov (United States)
Basta, Holly A; Palmenberg, Ann C
2014-08-01
Cardioviruses of the Encephalomyocarditis virus (EMCV) and Theilovirus species encode small, amino-terminal proteins called Leaders (L). Phosphorylation of the EMCV L (LE) at two distinct sites by CK2 and Syk kinases is important for virus-induced Nup phosphorylation and nucleocytoplasmic trafficking inhibition. Despite similar biological activities, the LE phosphorylation sites are not conserved in the Theiloviruses, Saffold virus (LS, SafV) or Theiler׳s murine encephalitis virus (LT, TMEV) sequences even though these proteins also become phosphorylated in cells and cell-free extracts. Site prediction algorithms, combined with panels of site-specific protein mutations now identify analogous, but not homologous phosphorylation sites in the Ser/Thr and Theilo protein domains of LT and LS, respectively. In both cases, recombinant AMP-activated kinase (AMPK) was reactive with the proteins at these sites, and also with LE, modifying the same residue recognized by CK2. Copyright © 2014 Elsevier Inc. All rights reserved.
8. Comparative analysis of the impact of geological activity on astronomical sites of the Canary Islands, Hawaii and Chile
CERN Document Server
Eff-Darwich, A; Rodriguez-Losada, J A; de la Nuez, J; Hernandez-Gutierrez, L E; Romero-Ruiz, M C
2009-01-01
An analysis of the impact of seismic and volcanic activity was carried out at selected astronomical sites, namely the observatories of El Teide (Tenerife, Canary Islands), Roque de los Muchachos (La Palma, Canary Islands), Mauna Kea (Hawaii) and Paranal (Chile) and the candidate site of Cerro Ventarrones (Chile). Hazard associated to volcanic activity is low or negligible at all sites, whereas seismic hazard is very high in Chile and Hawaii. The lowest geological hazard in both seismic and volcanic activity was found at Roque de los Muchachos observatory, in the island of La Palma.
9. The role of active site tyrosine 58 in Citrobacter freundii methionine γ-lyase.
Science.gov (United States)
Anufrieva, Natalya V; Faleev, Nicolai G; Morozova, Elena A; Bazhulina, Natalia P; Revtovich, Svetlana V; Timofeev, Vladimir P; Tkachev, Yaroslav V; Nikulin, Alexei D; Demidkina, Tatyana V
2015-09-01
In the spatial structure of methionine γ-lyase (MGL, EC 4.4.1.11) from Citrobacter freundii, Tyr58 is located at H-bonding distance to the oxygen atom of the phosphate "handle" of pyridoxal 5'-phosphate (PLP). It was replaced for phenylalanine by site-directed mutagenesis. The X-ray structure of the mutant enzyme was determined at 1.96Å resolution. Comparison of spatial structures and absorption spectra of wild-type and mutant holoenzymes demonstrated that the replacement did not result in essential changes of the conformation of the active site Tyr58Phe MGL. The Kd value of PLP for Tyr58Phe MGL proved to be comparable to the Kd value for the wild-type enzyme. The replacement led to a decrease of catalytic efficiencies in both γ- and β-elimination reactions of about two orders of magnitude as compared to those for the wild-type enzyme. The rates of exchange of C-α- and C-β- protons of inhibitors in D2O catalyzed by the mutant form are comparable with those for the wild-type enzyme. Spectral data on the complexes of the mutant form with the substrates and inhibitors showed that the replacement led to a change of rate the limiting step of the physiological reaction. The results allowed us to conclude that Tyr58 is involved in an optimal positioning of the active site Lys210 at some stages of γ- and β-elimination reactions. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.
10. Accommodation of GDP-Linked Sugars in the Active Site of GDP-Perosamine Synthase
Energy Technology Data Exchange (ETDEWEB)
Cook, Paul D.; Carney, Amanda E.; Holden, Hazel M. (UW)
2009-01-12
Perosamine (4-amino-4,6-dideoxy-d-mannose), or its N-acetylated form, is one of several dideoxy sugars found in the O-antigens of such infamous Gram-negative bacteria as Vibrio cholerae O1 and Escherichia coli O157:H7. It is added to the bacterial O-antigen via a nucleotide-linked version, namely GDP-perosamine. Three enzymes are required for the biosynthesis of GDP-perosamine starting from mannose 1-phosphate. The focus of this investigation is GDP-perosamine synthase from Caulobacter crescentus, which catalyzes the final step in GDP-perosamine synthesis, the conversion of GDP-4-keto-6-deoxymannose to GDP-perosamine. The enzyme is PLP-dependent and belongs to the aspartate aminotransferase superfamily. It contains the typically conserved active site lysine residue, which forms a Schiff base with the PLP cofactor. Two crystal structures were determined for this investigation: a site-directed mutant protein (K186A) complexed with GDP-perosamine and the wild-type enzyme complexed with an unnatural ligand, GDP-3-deoxyperosamine. These structures, determined to 1.6 and 1.7 {angstrom} resolution, respectively, revealed the manner in which products, and presumably substrates, are accommodated within the active site pocket of GDP-perosamine synthase. Additional kinetic analyses using both the natural and unnatural substrates revealed that the K{sub m} for the unnatural substrate was unperturbed relative to that of the natural substrate, but the k{sub cat} was lowered by a factor of approximately 200. Taken together, these studies shed light on why GDP-perosamine synthase functions as an aminotransferase whereas another very similar PLP-dependent enzyme, GDP-4-keto-6-deoxy-d-mannose 3-dehydratase or ColD, catalyzes a dehydration reaction using the same substrate.
11. Modeling the thermal dynamics of the active layer at two contrasting permafrost sites
Directory of Open Access Journals (Sweden)
J. Weismüller
2011-01-01
Full Text Available The thermal and hydraulic dynamics of unsaturated active layers are described in a one-dimensional numerical forward model. Hydraulic and thermal transport processes are coupled in a set of partial differential equations based on Richards' equation, conductive and convective heat flow and a phenomenological description of soil freezing. The model is applied to the detailed data sets of two rather different field sites, one in the Arctic on Svalbard and one on the Tibetan Plateau. Soil temperatures and water contents as well as important quantities like the thaw depth and the duration of the isothermal plateau can be reproduced. To examine the influence of different heat transport processes, three scenarios of different complexity are studied. We show that heat conduction is the dominant process at both sites. While representing this process is sufficient for rough thaw depth estimates, a more detailed representation is necessary for an accurate representation of the active layer thermal dynamics. With our detailed model, characteristic deviations between measurements and simulations can still be observed. As possible explanations we discuss downward vapor migration in the upper soil layer and mechanical deformations.
12. Lipase active-site-directed anchoring of organometallics: metallopincer/protein hybrids.
Science.gov (United States)
Kruithof, Cornelis A; Casado, Miguel A; Guillena, Gabriela; Egmond, Maarten R; van der Kerk-van Hoof, Anca; Heck, Albert J R; Klein Gebbink, Robertus J M; van Koten, Gerard
2005-11-18
The work described herein presents a strategy for the regioselective introduction of organometallic complexes into the active site of the lipase cutinase. Nitrophenol phosphonate esters, well known for their lipase inhibitory activity, are used as anchor functionalities and were found to be ideal tools to develop a single-site-directed immobilization method. A small series of phosphonate esters, covalently attached to ECE "pincer"-type d8-metal complexes through a propyl tether (ECE=[C6H3(CH2E)(2)-2,6]-; E=NR2 or SR), were designed and synthesized. Cutinase was treated with these organometallic phosphonate esters and the new metal-complex/protein hybrids were identified as containing exactly one organometallic unit per protein. The organometallic proteins were purified by membrane dialysis and analyzed by ESI-mass spectrometry. The major advantages of this strategy are: 1) one transition metal can be introduced regioselectively and, hence, the metal environment can potentially be fine-tuned; 2) purification procedures are facile due to the use of pre-synthesized metal complexes; and, most importantly, 3) the covalent attachment of robust organometallic pincer complexes to an enzyme is achieved, which will prevent metal leaching from these hybrids. The approach presented herein can be regarded as a tool in the development of regio- and enantioselective catalyst as well as analytical probes for studying enzyme properties (e.g., structure) and, hence, is a "proof-of-principle design" study in enzyme chemistry.
13. Roles of Conserved Active Site Residues in the Ketosynthase Domain of an Assembly Line Polyketide Synthase.
Science.gov (United States)
Robbins, Thomas; Kapilivsky, Joshuah; Cane, David E; Khosla, Chaitan
2016-08-16
Ketosynthase (KS) domains of assembly line polyketide synthases (PKSs) catalyze intermodular translocation of the growing polyketide chain as well as chain elongation via decarboxylative Claisen condensation. The mechanistic roles of ten conserved residues in the KS domain of Module 1 of the 6-deoxyerythronolide B synthase were interrogated via site-directed mutagenesis and extensive biochemical analysis. Although the C211A mutant at the KS active site exhibited no turnover activity, it was still a competent methylmalonyl-ACP decarboxylase. The H346A mutant exhibited reduced rates of both chain translocation and chain elongation, with a greater effect on the latter half-reaction. H384 contributed to methylmalonyl-ACP decarboxylation, whereas K379 promoted C-C bond formation. S315 played a role in coupling decarboxylation to C-C bond formation. These findings support a mechanism for the translocation and elongation half-reactions that provides a well-defined starting point for further analysis of the key chain-building domain in assembly line PKSs.
14. Photoaffinity ligands in the study of cytochrome p450 active site structure.
Science.gov (United States)
Gartner, Carlos Augusto
2003-04-01
While photoaffinity ligands have been widely used to probe the structures of many receptors and nucleic acid binding proteins, their effective use in the study of cytochrome p450 structure is less established. Nevertheless, significant advances in this field have been made since the technique was first applied to p450cam in 1979. In several cases, especially studies involving p450s of the 1A and 2B families, peptides covalently modified with photoaffinity ligands have been isolated and characterized. Some of these peptides were predicted by molecular modeling to line substrate binding regions of the enzymes. Other data obtained from such studies were more difficult to reconcile with theory. This review addresses the status of photoaffinity labeling as a tool for studying cytochrome p450 structure. In addition, potential future directions in this field are discussed, including the development of heme-directed agents and validation of their effectiveness as photoaffinity ligands using sperm whale myoglobin as a test protein. The potential for hydroxyaromatic compounds to serve as photoactivated probes of active site nucleophiles is also discussed. This class of compounds and its derivatives has long been known in the fields of photochemistry and photophysics to be precursors of reactive radicals and quinone methides that are likely to serve as effective active site probes of the p450s.
15. An open source cryostage and software analysis method for detection of antifreeze activity
DEFF Research Database (Denmark)
Lørup Buch, Johannes; Ramløv, H
2016-01-01
The aim of this study is to provide the reader with a simple setup that can detect antifreeze proteins (AFP) by inhibition of ice recrystallisation in very small sample sizes. This includes an open source cryostage, a method for preparing and loading samples as well as a software analysis method....... The entire setup was tested using hyperactive AFP from the cerambycid beetle, Rhagium mordax. Samples containing AFP were compared to buffer samples, and the results are visualised as crystal radius evolution over time and in absolute change over 30 min. Statistical analysis showed that samples containing...... AFP could reliably be told apart from controls after only two minutes of recrystallisation. The goal of providing a fast, cheap and easy method for detecting antifreeze proteins in solution was met, and further development of the system can be followed at https://github.com/pechano/cryostage....
16. An open source cryostage and software analysis method for detection of antifreeze activity.
Science.gov (United States)
Buch, J L; Ramløv, H
2016-06-01
The aim of this study is to provide the reader with a simple setup that can detect antifreeze proteins (AFP) by inhibition of ice recrystallisation in very small sample sizes. This includes an open source cryostage, a method for preparing and loading samples as well as a software analysis method. The entire setup was tested using hyperactive AFP from the cerambycid beetle, Rhagium mordax. Samples containing AFP were compared to buffer samples, and the results are visualised as crystal radius evolution over time and in absolute change over 30 min. Statistical analysis showed that samples containing AFP could reliably be told apart from controls after only two minutes of recrystallisation. The goal of providing a fast, cheap and easy method for detecting antifreeze proteins in solution was met, and further development of the system can be followed at https://github.com/pechano/cryostage.
17. Shrink wrapping redox-active crystals of polyoxometalate open frameworks with organic polymers via crystal induced polymerisation.
Science.gov (United States)
Takashima, Yohei; Miras, Haralampos N; Glatzel, Stefan; Cronin, Leroy
2016-06-14
We report examples of crystal surface modification of polyoxometalate open frameworks whereby the use of pyrrole or aniline as monomers leads to the formation of the corresponding polymers via an oxidative polymerization process initiated by the redox active POM scaffolds. Guest-exchange experiments demonstrate that the polymers can finely tune the guest exchange rate and their structural integrity is retained after the surface modifications. In addition, the formation of polyoxometalate-based self-fabricating tubes by the dissolution of Keggin-based network crystals were also modulated by the polymers, allowing a new type of hybrid inorganic polymer with an organic coating to be fabricated.
18. Analysis of surface binding sites (SBSs) in carbohydrate active enzymes with focus on glycoside hydrolase families 13 and 77
DEFF Research Database (Denmark)
Cockburn, Darrell; Wilkens, Casper; Ruzanski, Christian
2014-01-01
Surface binding sites (SBSs) interact with carbohydrates outside of the enzyme active site. They are frequently situated on catalytic domains and are distinct from carbohydrate binding modules (CBMs). SBSs are found in a variety of enzymes and often seen in crystal structures. Notably about half ...
19. Rate of hydrolysis in ATP synthase is fine-tuned by -subunit motif controlling active site conformation
KAUST Repository
Beke-Somfai, T.
2013-01-23
Computer-designed artificial enzymes will require precise understanding of how conformation of active sites may control barrier heights of key transition states, including dependence on structure and dynamics at larger molecular scale. F(o)F(1) ATP synthase is interesting as a model system: a delicate molecular machine synthesizing or hydrolyzing ATP using a rotary motor. Isolated F(1) performs hydrolysis with a rate very sensitive to ATP concentration. Experimental and theoretical results show that, at low ATP concentrations, ATP is slowly hydrolyzed in the so-called tight binding site, whereas at higher concentrations, the binding of additional ATP molecules induces rotation of the central γ-subunit, thereby forcing the site to transform through subtle conformational changes into a loose binding site in which hydrolysis occurs faster. How the 1-Å-scale rearrangements are controlled is not yet fully understood. By a combination of theoretical approaches, we address how large macromolecular rearrangements may manipulate the active site and how the reaction rate changes with active site conformation. Simulations reveal that, in response to γ-subunit position, the active site conformation is fine-tuned mainly by small α-subunit changes. Quantum mechanics-based results confirm that the sub-Ångström gradual changes between tight and loose binding site structures dramatically alter the hydrolysis rate.
20. Active Site Mapping of Human Cathepsin F with Dipeptide Nitrile Inhibitors.
Science.gov (United States)
Schmitz, Janina; Furtmann, Norbert; Ponert, Moritz; Frizler, Maxim; Löser, Reik; Bartz, Ulrike; Bajorath, Jürgen; Gütschow, Michael
2015-08-01
Cleavage of the invariant chain is the key event in the trafficking pathway of major histocompatibility complex class II. Cathepsin S is the major processing enzyme of the invariant chain, but cathepsin F acts in macrophages as its functional synergist which is as potent as cathepsin S in invariant chain cleavage. Dedicated low-molecular-weight inhibitors for cathepsin F have not yet been developed. An active site mapping with 52 dipeptide nitriles, reacting as covalent-reversible inhibitors, was performed to draw structure-activity relationships for the non-primed binding region of human cathepsin F. In a stepwise process, new compounds with optimized fragment combinations were designed and synthesized. These dipeptide nitriles were evaluated on human cysteine cathepsins F, B, L, K and S. Compounds 10 (N-(4-phenylbenzoyl)-leucylglycine nitrile) and 12 (N-(4-phenylbenzoyl)leucylmethionine nitrile) were found to be potent inhibitors of human cathepsin F, with Ki values nitriles from our study, a 3D activity landscape was generated to visualize structure-activity relationships for this series of cathepsin F inhibitors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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https://slideplayer.com/slide/2388495/
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# Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 1 Determining Loaded-Q for SRF Cavities Used In ERLs (What do you mean it is.
## Presentation on theme: "Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 1 Determining Loaded-Q for SRF Cavities Used In ERLs (What do you mean it is."— Presentation transcript:
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 1 Determining Loaded-Q for SRF Cavities Used In ERLs (What do you mean it is not perfect energy recovery?) May 23, 2007 Tom Powers
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 2 Outline Loaded Q for on crest beam. Loaded Q for complete energy recovery –Microphonic Effects Loaded Q for incomplete energy recovery –Why Incomplete energy recovery –Implications in RF loading and control –Implications for high current applications. Conclusions
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 3 Basic Equations For RF Source Power
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 4 Case 1 Standard Beam Loading Beam at or near on crest Power to beam is much greater than wall losses. Microphonics control power small compared to beam power Matched condition when cavity reflected power is zero and all klystron power goes into the beam.
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 5 RF Power and Phase Control Requirements as a Function of Matched Condition Loaded-Q For this example gradient = 20 MV/m, CEBAF upgrade cavity, microphonics equal 15 Hz peak
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 6 Case 2 Complete Energy Recovery 0 0 0 0 Net beam current equals zero Possible to run at very high loaded Q values Note above loaded Q’s above 5x10 8 β is no longer >> 1 and must be accounted for. Microphonic Control becomes critical.
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 7 Klystron and Phase Control Requirements as a Function of Loaded-Q, Ideal Energy Recovery Example is a CEBAF 7-cell upgrade cavity operated at 20 MV/m. Microphonics 10 Hz-peak excursion in frequency.
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 8 2-Pass Beam Incomplete Energy Recovery 1<165 1<-10 0.087<77
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 9 Incomplete Energy Recovery All terms of the power and phase equations now apply. In the case where the beam is close to 180º out of phase with each other the resultant beam current is near 90º off crest. –A substantial fraction of the power takes the form of “reactive” power –There is substantial phase variation in the klystron power. The cavity tuners respond such that the reactive power effects are short term in nature.
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 10 Why Would Anyone Have Incomplete Energy Recovery? Intentionally (An Example) When an FEL lases the energy of the exhaust beam changes in energy as shown above. This translates to a change in the path length and thus a phase shift in the second pass beam. In the JLAB FEL we have to do energy compaction on both the first and second pass beam. The first for bunch compression for improved lasing. The second so that we can comply with the energy acceptance of the dump bend. Unintentionally Because you do not get the phase of the second pass beam correct or it drifts. Synchrotron Light from Second Arc JLAB FEL No Lasing Weak Lasing Strong Lasing Increase in Energy
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 11 Theoretical Power Requirement for Two Pass Beam CEBAF upgrade cavity, E=10 MV/m, QL=2.0e7, peak microphonics = 10 Hz First pass at -10d, second pass 165d from crest.
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 12 The Effects of Cavity Tuning Our Tuning Algorithm In our machine the cavity is tuned with no beam loading such that the forward power is minimized. The RF phase difference between the forward power and the field probe power is then considered the reference phase. (For the purposes of this discussion the difference between this phase and the actual value is the detune phase.) The detune phase is then monitored and kept as a minimum during operations.
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 13 Tuning Effects With Off Crest Beam Loading Tuning Substituting this in leads to the following (after tuning)
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 14 Theoretical Power Requirement for Two Pass Beam Including Tuning Effects CEBAF upgrade cavity, E=10 MV/m, QL=2.0e7, peak microphonics = 10 Hz First pass at -10d, second pass 165d from crest.
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 15 Theoretical Dynamic Phase Control Requirement for Two Pass Beam Including Tuning Effects
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 16 Real Data From FEL3-5 Forward Power E=5.6 MV/m, QL=2.1e7, RF power calibration ~20% but linear First pass beam -10d second pass beam not well known.
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 17 Real Data From FEL3-5 Detune Phase
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 18 100 kW FEL Example Loaded-Q Selection 748.5 MHz, 5-Cell, (r/Q)=1000, 17 MV/m, E=16.7 MV/m, first pass phase -10d, second pass phase lasing 165d, not lasing 168. Resultant beam Not Lasing 5.2mA at 76.5d
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 19 100 kW FEL Pkly and Phase vs Current QL=3e6, dF=15 Hz,
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 20 Effect of 1d of Phase Slip on 100 mA Cavity Designed for Perfect Energy Recovery 7-Cell, 1500 MHz, 20 MV/m, dF=10 Hz, (r/Q)=960 Ω/m
Thomas Jefferson National Accelerator Facility CWL/Kovar/March 1, 2007 Page 21 Conclusions Dynamic loading due to incomplete energy recovery is an issue for all machines Some machines it is due to unintentional missmatch of second pass beam Some machines it is due to intentional missmatch due to changing beam conditions. Dynamic loading would be difficult to completely control using fast tuners, etc. Many systems will be effected by this. –LLRF system –Klystron selection –Fundimental Power Couplers –Machine design and prudent selection of phase parameters is important. Tools need to be implemented to measure this effect at low or pulsed current.
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https://link.springer.com/chapter/10.1007%2F978-3-319-95630-5_39
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# Method of Investigating Dynamic Operating Modes of Electrohydraulic Drive Systems with Movable Boundaries of Working Fluids
• A. I. Ozerskij
• N. A. Tseligorov
Conference paper
Part of the Lecture Notes in Mechanical Engineering book series (LNME)
## Abstract
The paper provides a methodology of the difficult hydropower-driven systems equipped with primary energy sources of two types: explosive motors and the electric motors operating under trying conditions of maintenance. The latter, alongside with hydropower-driven systems, are modeled as uniform heat-electro hydromechanical systems, optimum control with which one can carry out on the basis of a mechanotronic approach and a principle of a maximum developed by L.S. Pontrjagin. The method for investigating dynamic operating modes of electrohydraulic drive systems with movable boundaries of operating fluids was described. The method is original as it allows one to calculate dynamic operating modes of the abovementioned systems in the cases when fluids of these systems have movable boundaries of the following type: “fluid–gas” or “fluid–solid” (“fluid–piston”). The description of engineering, physical, and mathematical models of the investigated processes was presented.
## Keywords
Electrohydraulic systems Dynamic modes Movable boundaries Calculation method Engineering simulation Physical simulation Mathematical modeling
## References
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Basniev KS, Dmitriev N, Chilingar G et al (2012) Mechanics of fluid flow. Scrivener Publishing LLC, Wiley, 568 pGoogle Scholar
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Chikulaev DG, Shvarts KG (2017) Effect of rotation on the monotonic instability mode of advective flow in a horizontal incompressible fluid layer with rigid boundaries in the case of normal spiral perturbations. . Accessed 15 Dec 2017
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Pember RB, Anderson RW (2001) Comparison of direct Eulerian Godunov and Lagrange plus remap, artificial viscosity schemes. In: Proceedings of 14th AIAA computational fluid dynamics conference, AnaheimGoogle Scholar
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Ozerskij AI, Shoshiashvili ME (2014) The method of calculating dynamic modes of operation of electro-hydraulic drive with ampulized hydraulic system. Izv High Sch North-Cauc Reg Eng 1(148):52–60Google Scholar
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https://arxiv.org/abs/1902.04557
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Full-text links:
gr-qc
(what is this?)
# Title:Inferring neutron star properties from GW170817 with universal relations
Abstract: Because all neutron stars share a common equation of state, tidal deformability constraints from the compact binary coalescence GW170817 have implications for the properties of neutron stars in other systems. Using equation-of-state insensitive relations between macroscopic observables like moment of inertia ($I$), tidal deformability ($\Lambda$) and stellar compactness, we derive constraints on these properties as a function of neutron-star mass based on the LIGO-Virgo collaboration's canonical deformability measurement, $\Lambda_{1.4} = 190^{+390}_{-120}$. Specific estimates of $\Lambda$, $I$, dimensionless spin $\chi$, and stellar radius $R$ for a few systems targeted by radio or X-ray studies are extracted from the general constraints. We also infer the canonical neutron-star radius as $R_{1.4} = 10.9^{+1.9}_{-1.5}$ km at 90$\%$ confidence. We further demonstrate how a gravitational-wave measurement of $\Lambda_{1.4}$ can be combined with independent measurements of neutron-star radii to tighten constraints on the tidal deformability as a proxy for the equation of state. We find that GW170817 and existing observations of six thermonuclear bursters in low-mass X-ray binaries jointly imply $\Lambda_{1.4} = 196^{+92}_{-63}$ at the 90$\%$ confidence level.
Comments: 18 pages, 7 figures; corrected multimessenger tidal deformability constraint Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th) Cite as: arXiv:1902.04557 [gr-qc] (or arXiv:1902.04557v4 [gr-qc] for this version)
## Submission history
From: Philippe Landry [view email]
[v1] Tue, 12 Feb 2019 18:58:46 UTC (403 KB)
[v2] Fri, 22 Feb 2019 22:19:00 UTC (354 KB)
[v3] Mon, 4 Mar 2019 10:13:34 UTC (368 KB)
[v4] Tue, 12 Mar 2019 07:21:48 UTC (372 KB)
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https://diw-econ.de/en/publications/the-economic-importance-of-onshore-wind-energy-in-schleswig-holstein/
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# The economic importance of onshore wind energy in Schleswig-Holstein
DIW Econ was commissioned by the Schleswig-Holstein Regional Association of the German Wind Energy Association to investigate the economic significance of onshore wind energy in Schleswig-Holstein.
This study analyses, on the one hand, the investments in new wind energy plants and on the other hand, the revenues and costs arising from the operation and maintenance of existing wind energy plants. It will thus determine the effects of the wind energy sector on regional value-added, employment and tax revenues in Schleswig-Holstein. The overall effect of the three indicators can be divided into direct, indirect and induced effects.
The study concludes that onshore wind energy in Schleswig-Holstein in 2018 will have triggered economic effects for a total of 11,900 employees and 1.3 billion euros in gross value added. Besides, the wind energy sector generates public revenues of at least 45.6 million euros. This makes it an essential driver of Schleswig-Holstein’s regional economy.
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https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=132&t=27109
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## 9.25
Boltzmann Equation for Entropy: $S = k_{B} \ln W$
Rachel Lu_dis1H
Posts: 66
Joined: Fri Sep 29, 2017 7:06 am
Been upvoted: 1 time
### 9.25
since the question doesn't give you the amount of molecules, do you just assume that it's avogadro's constant?
Cooper1C
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am
### Re: 9.25
The question says "what might its residual molar entropy be?" so you would use avogadro's constant.
Angel Ni 2K
Posts: 50
Joined: Sat Jul 22, 2017 3:01 am
### Re: 9.25
They are asking for molar entropy, so there are 6.02E23 molecules.
Return to “Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy”
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https://www.esaral.com/q/given-that-the-standard-potentials-88394
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# Given that the standard potentials
Question:
Given that the standard potentials $\left(\mathrm{E}^{0}\right)$ of $\mathrm{Cu}^{2+} / \mathrm{Cu}$ and $\mathrm{Cu}^{+} /$ $\mathrm{Cu}$ are $0.34 \mathrm{~V}$ and $0.522 \mathrm{~V}$ respectively, the $\mathrm{E}^{0}$ of $\mathrm{Cu}^{2+} /$ $\mathrm{Cu}^{+}$is:
1. $+0.182 \mathrm{~V}$
2. $+0.158 \mathrm{~V}$
3. $-0.182 \mathrm{~V}$
4. $-0.158 \mathrm{~V}$
Correct Option: , 2
Solution:
$\mathrm{Cu}^{2+}+2 e^{-} \longrightarrow \mathrm{Cu}, \Delta \mathrm{G}_{1}^{0}=-2 \mathrm{~F}(0.34) \ldots$ (i)
$\mathrm{Cu}^{+}+e^{-} \longrightarrow \mathrm{Cu}, \Delta \mathrm{G}_{2}^{\circ}=-\mathrm{F}(0.522) \quad$...(ii)
Subtract (ii) from (i)
$\mathrm{Cu}^{2+}+\mathrm{e}^{-} \longrightarrow \mathrm{Cu}^{+}, \quad \Delta \mathrm{G}_{3}^{\circ}=-\mathrm{F}\left(\mathrm{E}^{0}\right)$
$\therefore \Delta \mathrm{G}_{1}^{\circ}-\Delta \mathrm{G}_{2}^{\circ}=\mathrm{G}_{3}^{\circ}$
$\Rightarrow-\mathrm{FE}^{\circ}=-2 \mathrm{~F}(0.34)+\mathrm{F}(0.522)$
$\Rightarrow \mathrm{E}^{\circ}=0.68-0.522=0.158 \mathrm{~V}$
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https://socratic.org/questions/how-do-you-solve-4-x-1-2
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Precalculus
Topics
# How do you solve 4^x = 1/2?
Apr 1, 2016
$x = - \frac{1}{2}$
#### Explanation:
Take the natural logarithm of both sides of the equation
$\ln | {4}^{x} | = \ln | \frac{1}{2} |$
Rewrite using properties of exponents
$x \ln | 4 | = \ln | \frac{1}{2} |$
$x \ln | {2}^{2} | = \ln | 1 | - \ln | 2 |$
$2 x \ln | 2 | = 0 - \ln | 2 |$
$x = \frac{- \ln | 2 |}{2 \ln | 2 |}$
$x = - \frac{1}{2}$
Apr 3, 2016
#### Explanation:
Rewriting the exponents in a common base:
Don't forget that $\frac{1}{{a}^{n}} = {a}^{-} n$. Thus, $\frac{1}{2} = {2}^{-} 1$.
${\left({2}^{2}\right)}^{x} = {2}^{-} 1$
Using the exponent property ${\left({a}^{n}\right)}^{m} = {a}^{n \times m}$, we get the following:
${2}^{2 x} = {2}^{-} 1$
We can eliminate the bases now and solve the simple linear equation.
$2 x = - 1$
$x = - \frac{1}{2}$
Here are a few helpful exponent rules to know when working with harder problems:
•a^n xx a^m = a^(n + m)
•a^n/a^m = a^(n - m)
•a^(n/m) = root(m)(a^n)
Practice exercises:
1. Solve for x.
${3}^{2 x + 1} \times {9}^{x - 3} = {27}^{4 x - 5}$
$\frac{{4}^{2 x + 5}}{{8}^{3 x - 2}} = {16}^{2 x}$
Challenge Problem:
Solve for x in the equation $\sqrt{12} \times \sqrt[x]{12} = \sqrt[15]{12}$
Good luck!
##### Impact of this question
194 views around the world
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http://math.stackexchange.com/questions/55305/subset-relations-among-sobolev-spaces-and-their-duals
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# subset relations among Sobolev spaces and their duals
This may be a rather dense question, but I would nevertheless be grateful for some guidance.
The question has to do with the Sobolev spaces $H^m (\Omega)$ on an open bounded domain $\Omega$ of $\mathbb{R}^n$, where $m \geq 0$ is integer. These are Hilbert spaces; thus the Riesz representation theorem tells us that there is a one-to-one and onto correspondence between elements of $H^m (\Omega)$ and elements of its dual $H^{-m} (\Omega)$. Yet, we also have the inclusion property $H^{m} (\Omega) \subset L_2 (\Omega) \subset H^{-m} (\Omega)$ (e.g. Oden and Reddy, Intro. to the Mathematical Theory of Finite Elements, p. 108). How can both of these hold? In other words, how can there be a one-to-one and onto correspondence between $H^m (\Omega)$ and $H^{-m} (\Omega)$, and yet the former is a strict subset of the latter?
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That's a problem pretty much every one learning about Sobolev spaces seems to encounter sooner or later, see here. – lvb Aug 3 '11 at 11:45
@user14178: A bijection is not the same thing as equality. The set of all even numbers is in bijection with the set of all numbers, but is also a proper subset. (This is one of the possible definitions for an infinite set.) – Zhen Lin Aug 3 '11 at 11:58
The dual space is the space of continuous linear functionals, and for a statement like $H^m \subset (H^m)^*$ to make sense one has to define a way to interpret functions as functionals, i.e. a linear embedding $H^m \to (H^m)^*$. There are two seemingly natural candidates: $$i_R(u)(v):=\left < u,v \right >_{H^m}$$ and $$i_D(u)(v):=\left < u,v \right >_{L^2}$$ The strictness of the inclusion translates to the question whether the embedding is an isomorphism, and it turns out that $i_R$ is an isomorphism according to the representation theorem, but $i_D$ is not! However, in accordance with distribution theory, $i_D$ is universally used to identify functions with functionals.
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Thanks for the pointers and the clear explanation. The apparent paradox is resolved by realizing that the inclusions are effected with the L_2 duality pairing and not the H^1, as you said. – Mark Rashid Aug 4 '11 at 6:05
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https://www.earth-syst-dynam.net/9/1/2018/
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Journal cover Journal topic
Earth System Dynamics An interactive open-access journal of the European Geosciences Union
Journal topic
Earth Syst. Dynam., 9, 1-14, 2018
https://doi.org/10.5194/esd-9-1-2018
Earth Syst. Dynam., 9, 1-14, 2018
https://doi.org/10.5194/esd-9-1-2018
Research article 11 Jan 2018
Research article | 11 Jan 2018
# Contrasting terrestrial carbon cycle responses to the 1997/98 and 2015/16 extreme El Niño events
Terrestrial responses to extreme El Niños
Jun Wang1,2, Ning Zeng2,3, Meirong Wang4, Fei Jiang1, Hengmao Wang1, and Ziqiang Jiang1 Jun Wang et al.
• 1International Institute for Earth System Science, Nanjing University, Nanjing, China
• 2State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Beijing, China
• 3Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA
• 4Joint Center for Data Assimilation Research and Applications/Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science & Technology, Nanjing, China
Abstract
Large interannual atmospheric CO2 variability is dominated by the response of the terrestrial biosphere to El Niño–Southern Oscillation (ENSO). However, the behavior of terrestrial ecosystems differs during different El Niños in terms of patterns and biological processes. Here, we comprehensively compare two extreme El Niños (2015/16 and 1997/98) in the context of a multi-event “composite” El Niño. We find large differences in the terrestrial carbon cycle responses, even though the two events were of similar magnitude.
More specifically, we find that the global-scale land–atmosphere carbon flux (FTA) anomaly during the 1997/98 El Niño was 1.64 Pg C yr−1, but half that quantity during the 2015/16 El Niño (at 0.73 Pg C yr−1). Moreover, FTA showed no obvious lagged response during the 2015/16 El Niño, in contrast to that during 1997/98. Separating the global flux by geographical regions, we find that the fluxes in the tropics and extratropical Northern Hemisphere were 1.70 and 0.05 Pg C yr−1 during 1997/98, respectively. During 2015/16, they were 1.12 and 0.52 Pg C yr−1, respectively. Analysis of the mechanism shows that, in the tropics, the widespread drier and warmer conditions caused a decrease in gross primary productivity (GPP; 0.73 Pg C yr−1) and an increase in terrestrial ecosystem respiration (TER; 0.62 Pg C yr−1) during the 1997/98 El Niño. In contrast, anomalously wet conditions occurred in the Sahel and East Africa during 2015/16, which caused an increase in GPP, compensating for its reduction in other tropical regions. As a result, the total 2015/16 tropical GPP and TER anomalies were 0.03 and 0.95 Pg C yr−1. GPP dominance during 1997/98 and TER dominance during 2015/16 accounted for the phase difference in their FTA. In the extratropical Northern Hemisphere, the large difference occurred because temperatures over Eurasia were warmer during the 2015/16, as compared with the cooling seen during the 1997/98 and the composite El Niño. These warmer conditions enhanced GPP and TER over Eurasia during the 2015/16 El Niño, while these fluxes were suppressed during 1997/98. The total extratropical Northern Hemisphere GPP and TER anomalies were 0.63 and 0.55 Pg C yr−1 during1997/98, and 1.90 and 1.45 Pg C yr−1 during 2015/16, respectively. Additionally, wildfires played a less important role during the 2015/16 than during the 1997/98 El Niño.
1 Introduction
The atmospheric CO2 growth rate has significant interannual variability, greatly influenced by the El Niño–Southern Oscillation (ENSO) (Bacastow, 1976; Keeling et al., 1995). This interannual variability primarily stems from terrestrial ecosystems (Bousquet et al., 2000; Zeng et al., 2005). There is also a general consensus that the tropical terrestrial ecosystems account for the terrestrial carbon variability (Zeng et al., 2005; Cox et al., 2013; Peylin et al., 2013; Wang et al., 2013, 2016). They tend to release anomalous levels of carbon flux during El Niño episodes, and take up carbon during La Niña events (Zeng et al., 2005; Wang et al., 2016). Recently, Ahlstrom et al. (2015) further suggested that ecosystems in semi-arid regions dominated the terrestrial carbon interannual variability, with a 39 % contribution.
The terrestrial dominance primarily results from the driver–response mechanisms in climate variability (especially in temperature and precipitation) caused by ENSO and plant/soil physiology (Tian et al., 1998; Zeng et al., 2005; Wang et al., 2016; Jung et al., 2017). The land–atmosphere carbon flux (FTA – positive sign meaning a flux into the atmosphere) can mainly be attributed to the imbalance between the gross primary productivity (GPP) and terrestrial ecosystem respiration (TER) according to ${F}_{\text{TA}}\cong \text{TER}-\text{GPP}+{\mathrm{C}}_{\text{fire}}$, where the carbon flux from wildfires (Cfire) is generally much smaller than the GPP or TER. Variations in each, or all, result in the changes in FTA.
Based on a dynamical global vegetation model (DGVM), Zeng et al. (2005) found that net primary productivity (NPP) contributed to almost three quarters of the tropical FTA interannual variability. Multi-model simulations involved in the TRENDY project and CMIP5 have consistently suggested that NPP or GPP dominate the terrestrial carbon variability (Piao et al., 2013; Ahlstrom et al., 2015; Kim et al., 2016; Wang et al., 2016).
These biological process analyses suggest that precipitation variation is the dominant climate factor in controlling FTA interannual variability (Tian et al., 1998; Zeng et al., 2005; Qian et al., 2008; Ahlstrom et al., 2015; Wang et al., 2016). Qian et al. (2008) calculated the contributions of tropical precipitation and temperature as 56 and 44 %, respectively, based on model sensitivity experiments. Eddy covariance network observations have suggested that the interannual carbon flux variability over tropical and temperate regions is controlled by precipitation, while boreal ecosystem carbon fluxes are more affected by temperature and radiation (Jung et al., 2011). At the same time, there is a significant positive correlation between the atmospheric CO2 growth rate and mean tropical land temperature (Cox et al., 2013; Wang et al., 2013, 2014; Anderegg et al., 2015). Regression analysis indicates an anomaly of approximately 3.5 Pg C yr−1 in the CO2 growth rate with a 1 C increase in tropical land temperature, whereas a weaker interannual coupling exists between the CO2 growth rate and tropical land precipitation (Wang et al., 2013). Clark et al. (2003) and Doughty et al. (2008) also concluded, based on in situ observations, that warming anomalies can reduce tropical tree growth and CO2 uptake. Therefore, considering this strong emergent linear relationship, these studies (Clark et al., 2003; Doughty et al., 2008; Cox et al., 2013; Wang et al., 2013, 2014; Anderegg et al., 2015) have suggested that temperature dominates the interannual variability of the FTA or CO2 growth rate. To reconcile these contradictory reports, Jung et al. (2017) showed that the temporal and spatial compensatory effects in water availability link the yearly global FTA variability to temperature. Fang et al. (2017) suggested an ENSO-phase-dependent interplay between water availability and temperature in controlling the tropical terrestrial carbon cycle response to climate variability.
Apart from these long-term time series studies on the interannual FTA or CO2 growth rate variability, we should keep in mind that the terrestrial carbon cycle responds in a unique way in terms of its strength, spatial patterns, and biological processes to every El Niño/La Niña event, because of the ENSO diversity with different spatial patterns and evolutions (Schwalm, 2011; Capotondi et al., 2015). For example, wildfires played an important role in the FTA anomalies during the 1997/98 El Niño (van der Werf et al., 2004). Therefore, it is important to have clear insight into the impacts of individual ENSO events on the terrestrial carbon cycle, and this is best achieved through representative case studies. Recently, one of the three extreme El Niño events in recorded history occurred in 2015/16 (https://www.esrl.noaa.gov/psd/enso/current.html). Because of the interference of the El Chichón eruption during the extreme El Niño case in 1982/83, we chose to compare in detail the response of terrestrial ecosystems in the other two extreme El Niño events, i.e., in 1997/98 and 2015/16, in the context of a multi-event “composite” El Niño, based on the VEGAS DGVM in its near-real-time framework and inversion datasets (Copernicus Atmosphere Monitoring Service (CAMS), Monitoring Atmospheric Composition & Climate (MACC), and CarbonTracker). The purpose is to clarify the different responses of biological processes in these two extreme events.
The paper is organized as follows. Section 2 describes the mechanistic carbon cycle model used, its drivers, and reference datasets. Section 3 presents the results of the total terrestrial carbon flux anomalies and spatial patterns, along with their mechanisms. Finally, a discussion and concluding remarks are provided in Sect. 4.
2 Model, datasets, and methods
## 2.1 Mechanistic carbon cycle model and its drivers
We used the state-of-the-art VEGAS DGVM, version 2.4, in its near-real-time framework, to investigate the responses of terrestrial ecosystems to El Niño events. VEGAS has been widely used to study the terrestrial carbon cycle on its seasonal cycle, interannual variability, and long-term trends (Zeng et al., 2004, 2005, 2014). The model has also extensively participated in international carbon modeling projects, such as the Coupled Climate–Carbon Cycle Model Intercomparison Project (C4MIP; Friedlingstein et al., 2006), the TRENDY project (Sitch et al., 2015) and the Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP; Huntzinger et al., 2013). A detailed description of the model structure and biological processes can be found in the appendix of Zeng et al. (2005). We ran VEGAS at the $\mathrm{0.5}{}^{\circ }×\mathrm{0.5}{}^{\circ }$ horizontal resolution from 1901 until the end of 2016, and focused on the period from 1980 to 2016.
The climate fields and boundary forcings used to run VEGAS were as follows:
• (1)
Precipitation datasets generated by combining the Climatic Research Unit (CRU) Time-series (TS) version 3.22 (University of East Anglia Climatic Research Unit et al., 2014), NOAA's Precipitation Reconstruction over Land (PREC/L) (Chen et al., 2002), and the NOAA–NCEP Climate Anomaly Monitoring System-Outgoing Longwave Radiation Precipitation Index (CAMS-OPI) (Janowiak and Xie, 1999).
• (2)
Temperature data from the CRU TS3.22 before the year 2013, generated by combining the CRU 1981–2010 climatology and the Goddard Institute for Space Studies (GISS) Surface Temperature Analysis (GISTEMP) (Hansen et al., 2010) after 2013.
• (3)
Downward shortwave radiation from the driver datasets in MsTMIP (Wei et al., 2014) before 2010, with the value of the year 2010 repeated for subsequent years.
• (4)
The gridded cropland and pasture land use datasets integrated from the History Database of the Global Environment (HYDE) (Klein Goldewijk et al., 2011) with a linear extrapolation in 2016.
## 2.2 Reference datasets
We selected a series of reference datasets to compare to the VEGAS simulation. The atmospheric CO2 concentrations were from the monthly in situ CO2 datasets at the Mauna Loa Observatory, Hawaii (Keeling et al., 1976). The Niño 3.4 (120 W–170 W, 5 S–5 N) sea surface temperature anomaly (SSTA) data were from the NOAA's Extended Reconstructed Sea Surface Temperature (ERSST) dataset, version 4 (Huang et al., 2015), with a 3-month running average. We compared the CAMS (1980–2015) and MACC (1980–2014) inversion results (Chevallier, 2013) and the CarbonTracker2016 (2000–2015) with the CarbonTracker near-real-time results from 2016 (Peters et al., 2007) with VEGAS. The FTA in CarbonTracker was calculated by the sum of the posterior biospheric flux and its imposed fire emissions. The Satellite-based fire emissions were from the Global Fire Emissions Database version 4 (GFEDv4) from 1997 through 2014 (Randerson et al., 2015). Owing to the high correlation between the solar-induced chlorophyll fluorescence (SIF) and terrestrial GPP (Guanter et al., 2014), we selected the monthly satellite SIF from the GOME2_F version 26 from 2007 to 2016 (Joiner et al., 2012). We also compared the enhanced vegetation index (EVI) from MODIS MOD13C2 (Didan, 2015) with the simulated leaf area index (LAI) anomalies.
## 2.3 Methods
To calculate the anomalies during the El Niño events, we first removed the long-term climatology in each dataset for getting rid of seasonal cycle signals. We then detrended them based on the linear regression, because the trend was mainly caused by long-term CO2 fertilization and climate change. We used these detrended monthly anomalies to investigate the impacts of El Niño events on the terrestrial carbon cycle.
Figure 1Interannual variability (IAV) in the sea surface temperature anomaly (SSTA) and carbon cycle. (a) ERSST4 Niño3.4 Index (units: K) using the 3-month running averaged SSTA for the Niño 3.4 region (5 N–5 S, 120–170 W). (b) IAV in the Mauna Loa CO2 growth rate (CGR; units: Pg C yr−1). The CGR is calculated as the difference between the monthly mean in adjacent years. The dashed line is the detrended monthly anomaly and the solid line is smoothed by the Butterworth filtering. (c) IAV in the land–atmosphere carbon fluxes (FTA; units: Pg C yr−1). The blue and orange solid lines are the smoothed results of the MACC and CAMS inversions, respectively. The gray dashed line is the detrended anomaly and the black one is the smoothed result from the VEGAS model simulation. The green solid line is the smoothed CarbonTracker result.
3 Results
## 3.1 Total terrestrial carbon flux anomalies
Three extreme El Niño events (1982/83, 1997/98, and 2015/16) occurred from 1980 to 2016, with their maximum SSTAs above 2.0 K (Fig. 1a). An El Niño event tends to anomalously increase the atmospheric CO2 growth rate (Fig. 1b); therefore, there are two significant anomalous increases in CO2 growth rate that correspond to the 1997/98 and 2015/16 El Niño events, although the maximum increase in 2015/16 was slightly less than that in 1997/98. Because of the diffuse light disturbance (Mercado et al., 2009) of the Mount El Chichón eruption during the 1982/83 El Niño on the canonical coupling between the anomalies of the CO2 growth rate anomalies and El Niño events, we mainly focused on the 1997/98 and 2015/16 El Niño events in this study. The interannual variability of the atmospheric CO2 growth rate principally originates from the terrestrial ecosystems (Fig. 1c). The correlation coefficient between the CO2 growth rate anomalies and the global FTA simulated by VEGAS was 0.60 (p<0.05). In order to evaluate the performance of the VEGAS simulation on the interannual timescale, we also present CAMS, MACC, and CarbonTracker inversion results. The CAMS and MACC inversions were nearly the same, with a correlation coefficient of approximately 0.60 (p<0.05) with VEGAS. From 2000 to 2016, CarbonTracker was highly correlated with VEGAS (r=0.67, p<0.05). These high correlation coefficients between VEGAS and the reference datasets indicate that VEGAS can capture the terrestrial carbon cycle interannual variability well.
Figure 2Evolutions of the global FTA along with the development of El Niño. (a) the SSTA in the composite (black), 1997/98 (blue), and 2015/16 (red) El Niño events. (b) The FTA anomalies in the El Niño composite analysis. The black solid line denotes the Mauna Loa CGR, and the red and blue lines show the VEGAS and mean of the CAMS and MACC inversions, respectively. The shaded areas in (a) and (b) show the 95 % confidence intervals of the variables in the composite, derived in 1000 bootstrap estimates. (c) The FTA anomalies during the 1997/98 El Niño events. The arrows demonstrate the time periods during which we calculate the carbon flux anomalies listed/presented in the table and figures. (d) The FTA anomalies during the 2015/16 El Niño. The purple line denotes the result of the CarbonTracker2016 and CarbonTracker near-real-time datasets.
Table 1Lists of El Niño events from 1980 until 2016.
There were 10 El Niño events from 1980 to 2016, each with a different duration and strength (Table 1). According to the definition of El Niño, these 10 events can be categorized into two weak (with a 0.5 to 0.9 SSTA), three moderate (1.0 to 1.4), two strong (1.5 to 1.9), and three very strong (≥2.0) events. During the 1997/98 El Niño, the positive SSTA lasted from April 1997 to June 1998, while the positive SSTA occurred in winter 2014, and extended to June 2016 in the 2015/16 El Niño (Fig. 2a). However, every El Niño event always peaks in winter (November or December; Fig. 2a). Considering this phase-lock phenomenon in the El Niño events, we produced a composite analysis (excluding 1982/83 and 1991/92, because of the diffuse radiation disturbances) as the background responses of the terrestrial carbon cycle to El Niño events.
Figure 3Evolutions of FTA over the extratropical Northern Hemisphere (23 N–90 N) and tropical regions (23 S–23 N) along with the development of El Niño. (a, b) Composite results with the VEGAS simulation (red solid line) and the mean of the CAMS and MACC inversions (blue solid line). The shaded areas show the 95 % confidence intervals of the variables in the composite, derived in 1000 bootstrap estimates. (c, d) The FTA anomalies during the 1997/98 El Niño. (e, f) The FTA anomalies in the 2015/16 El Niño with VEGAS (red solid line) and CarbonTracker (purple solid line).
Figure 4Evolutions of gross primary productivity (GPP, green lines) and terrestrial ecosystem respiration (TER, brown lines) over the extratropical Northern Hemisphere (23 N–90 N) and tropical regions (23 S–23 N) along with the development of El Niño. (a, b) El Niño composite results. The shaded areas show the 95 % confidence intervals of the variables in the composite, derived in 1000 bootstrap estimates. (c, d) Results of the 1997/98 El Niño. (e, f) Results of the 2015/16 El Niño.
The evolution of the global FTA anomalies in VEGAS, the mean of CAMS and MACC, and CarbonTraker in the composite, 1997/98, and 2015/16 El Niño events are closely consistent with the Mauna Loa CGR anomalies (Fig. 2b–d). The peaks of the FTA and the Mauna Loa CGR anomalies in the 1997/98 and 2015/16 El Niño events were much stronger than those in the composite analysis. Importantly, there were significant terrestrial lagged responses in the composite and 1997/98 El Niño events, with the peak of the FTA anomaly occurring from March to April in the El Niño decaying year (Fig. 2b and c), consistent with previous studies (Qian et al., 2008; Wang et al., 2016). However, this lagged terrestrial response disappeared in the Mauna Loa CGR, VEGAS, and CarbonTracker in the 2015/16 El Niño (Fig. 2d). In June 2016, the FTA anomaly of VEGAS and CarbonTracker reduced significantly (the sign changed), whereas the Mauna Loa CGR reduced only slightly (no sign change; Fig. 2d). A similar phenomenon also occurred earlier, from April to July 2015. In addition, the anomalous carbon release caused by the El Niño lasted from approximately July in the El Niño developing year to October in the El Niño decaying year (Fig. 2b–d). For simplicity, we calculated the total anomalies of all El Niño events during this period in the next context, taking the terrestrial lagged responses into account (Wang et al., 2016).
Based on the major geographical regions, we separated global FTA anomaly into the extratropical Northern Hemisphere (23 N–90 N), tropical regions (23 S–23 N), and extratropical Southern Hemisphere (60 S–23 S). Because the FTA anomaly over the extratropical Southern Hemisphere is generally smaller, we mainly present the evolutions of the FTA over the extratropical Northern Hemisphere and the tropical regions in Fig. 3. Comparing the global and tropical FTA anomalies, we find that the FTA anomalies in the tropical regions dominated the global FTA during these El Niño events (Fig. 3b, d and f), in accordance with previous conclusions (Zeng et al., 2005; Peylin et al., 2013). The FTA anomalies over the extratropical Northern Hemisphere were nearly neutral in VEGAS for the composite and the 1997/98 El Niño events (Fig. 3a and c). However, there was clear anomalous uptake from April to September in 2016 simulated by VEGAS (Fig. 3e), compensating for the carbon release over the tropics (Fig. 3f). This anomalous uptake caused the globally negative FTA anomalies that occurred from May to September in 2016 (Fig. 2d). Similar anomalous uptake also occurred over the extratropical Northern Hemisphere from April to July 2015. This anomalous uptake in VEGAS was to some extent consistent with the results from CarbonTracker, and accounted for the global FTA reduction mentioned above during these periods. Comparing the behaviors between the Mauna Loa CGR and the FTA anomalies, the Mauna Loa CGR, which originates from a tropical observatory, does not reflect the signals over the extratropical Northern Hemisphere in time (Figs. 2d and 3e).
Because FTA mainly stems from the difference between TER and GPP, we present the TER and GPP anomalies in Fig. 4 to clearly explain the FTA anomalies. Anomalously negative GPP dominated the FTA anomaly in the tropics in the composite and the 1997/98 El Niño episodes, with the significant lagged responses (peak at approximately May of the El Niño decaying year; Fig. 4b and d). Furthermore, clear positive TER anomalies occurred from October 1997 to April 1998 (Fig. 4d), contributing to the tropical carbon release during this period (Fig. 3d). In contrast, anomalously positive TER dominated the FTA anomaly in the tropics during the 2015/16 El Niño, without clear lags (Fig. 4f), accounting for the disappearance of the terrestrial FTA lagged response (Fig. 2d). In the extratropical Northern Hemisphere, the increased GPP and TER from April to October were nearly identical in the composite and in 1998 (Fig. 4a and c), causing neutral FTA anomalies (Fig. 3a and c). However, the increased GPP was stronger than the increased TER from April to July 2015 and from April to September 2016 (Fig. 4e), resulting in the anomalous uptake in FTA (Figs. 2d and 3e).
Table 2Carbon flux anomalies during El Niño events, calculated as the mean from July in the El Niño developing year to October in the El Niño decaying year. Flux units are in Pg C yr−1.
We calculated the total carbon flux anomalies from July in the El Niño developing year to October in the El Niño decaying year. The composite global FTA anomaly during the El Niño events in VEGAS was approximately 0.60 Pg C yr−1, dominated by tropical ecosystems with 0.61 Pg C yr−1 (Table 2). These anomalies were comparable to the mean of the CAMS and MACC inversion results, at 0.92±0.01 globally and 0.66±0.03Pg C yr−1 in the tropics. In these two extreme cases, a strong anomalous carbon release occurred during the 1997/98 El Niño, with a value of 1.64 Pg C yr−1, which was less than the 2.57 Pg C yr−1 in the CAMS and MACC inversions, while only 0.73 Pg C yr−1 was released during the 2015/16 El Niño, which was comparable to the 0.82 Pg C yr−1 in CarbonTracker. However, the FTA anomalies in the tropical regions dominated the global FTA anomalies in both cases, with values of 1.70 and 1.12 Pg C yr−1 in VEGAS, respectively. Furthermore, anomalous carbon uptake simulated by VEGAS over the extratropical Northern Hemisphere canceled out the 0.52 Pg C yr−1 anomalous release in the tropics during the 2015/16 El Niño, whereas it was neutral (0.05 Pg C yr−1) in the 1997/98 El Niño. The FTA anomaly was relatively smaller in the extratropical Southern Hemisphere.
Figure 5Spatial FTA anomalies calculated from July in the El Niño developing year to October in the El Niño decaying year (units: $\mathrm{g}\phantom{\rule{0.125em}{0ex}}\mathrm{C}\phantom{\rule{0.125em}{0ex}}{\mathrm{m}}^{-\mathrm{2}}\phantom{\rule{0.125em}{0ex}}{\mathrm{yr}}^{-\mathrm{1}}$). (a–c) Results of the composite, 1997/98, and 2015/16 El Niño events simulated by VEGAS, respectively. (d–e) The averaged results of CAMS and MACC in the composite and 1997/98 El Niños. (f) The 2015/16 El Niño FTA anomaly in CarbonTracker. The stippled areas in (a) and (d) are significant above the 90 % level, estimated by Student's t test.
In terms of the biological processes, the GPP (0.73 Pg C yr−1) and TER (0.62 Pg C yr−1) in the tropics together drove the anomalous FTA during 1997/98, while the TER (0.95 Pg C yr−1) mainly drove the anomalous FTA during 2015/16, with a near-neutral GPP of 0.03 Pg C yr−1 (Table 2). These data confirmed that the GPP played a more important role in the 1997/98 event, while TER was dominant during the 2015/16 El Niño. In the extratropical Northern Hemisphere, GPP and TER canceled each other out. They were 0.13 and 0.08 Pg C yr−1 in the composite analysis, and 0.63 and 0.55 Pg C yr−1 in the 1997/98 El Niño, respectively, causing the near-neutral FTA anomaly in that region. However, the GPP and TER in the 2015/16 El Niño were much stronger than those in the composite or the 1997/98 El Niño. Importantly, the GPP (1.90 Pg C yr−1) was stronger than the TER (1.45 Pg C yr−1) in the 2015/16 El Niño, causing the significant carbon uptake. The FTA anomaly caused by wildfires also played an important role during the 1997/98 El Niño, with a global value of 0.42 Pg C yr−1 in VEGAS, which was consistent with the GFED fire data product (0.82 Pg C yr−1). The effect of wildfires on the FTA anomaly during the 1997/98 El Niño episode has been previously suggested by van der Werf et al. (2004), whereas it was close to zero (0.05 Pg C yr−1) during the 2015/16 El Niño.
Figure 6Anomalies of soil wetness, air temperature (units: K), GPP ($\mathrm{g}\phantom{\rule{0.125em}{0ex}}\mathrm{C}\phantom{\rule{0.125em}{0ex}}{\mathrm{m}}^{-\mathrm{2}}\phantom{\rule{0.125em}{0ex}}{\mathrm{yr}}^{-\mathrm{1}}$), and TER ($\mathrm{g}\phantom{\rule{0.125em}{0ex}}\mathrm{C}\phantom{\rule{0.125em}{0ex}}{\mathrm{m}}^{-\mathrm{2}}\phantom{\rule{0.125em}{0ex}}{\mathrm{yr}}^{-\mathrm{1}}$) from July in the El Niño developing year to October in the El Niño decaying year in the composite, 1997/98, and 2015/16 El Niño episodes, respectively. (a–d) Results of the composite analyses. The stippled areas are significant above the 90 % levels estimated by Student's t test. (e–h) Anomalies during the 1997/98 El Niño. (i–l) Anomalies during the 2015/16 El Niño.
## 3.2 Spatial features and its mechanisms
The regional responses of terrestrial ecosystems to El Niño events are inhomogeneous, principally due to the anomalies in climate variability. In the composite El Niño analysis (Fig. 5a), land consistently released carbon flux in the tropics, while there was an anomalous carbon uptake over North America as well as central and eastern Europe. These regional responses were generally consistent with the CAMS and MACC inversion results (Fig. 5d).
During the 1997/98 El Niño episode, the tropical responses were analogous to the composite results, except for stronger carbon releases. North America and central and eastern China had stronger carbon uptake, whereas Europe and Russia had stronger carbon release (Fig. 5b). However, during the 2015/16 El Niño, anomalous carbon uptake occurred over the Sahel and East Africa, compensating for the carbon release over the other tropical regions (Fig. 5c). This made the total FTA anomaly in the tropics in 2015/16 less than that in 1997/98 (Fig. 3d and f; and Table 2). North America had anomalous carbon uptake, similar to that in the composite and the 1997/98 El Niño, while central and eastern Russia had anomalous carbon uptake during the 2015/16 El Niño (Fig. 5c), which was opposite to the carbon release in the composite and the 1997/98 El Niño. This opposite behavior of the boreal forests over central and eastern Russia clearly contributed to the total uptake over the extratropical Northern Hemisphere (Table 2). Moreover, these regional responses during the 2015/16 El Niño were significantly consistent with the CarbonTracker result (Fig. 5f).
To better explain these regional carbon flux anomalies, we present the main climate variabilities of soil wetness (mainly caused by precipitation) and air temperature, and the biological processes of GPP and TER in Fig. 6. In the composite analyses, the soil wetness is generally reduced in the tropics (Fig. 6a), causing the widespread decrease in GPP (Fig. 6b), which has been verified by model sensitivity experiments (Qian et al., 2008). At the same time, air temperature was anomalously warmer, contributing to the increase in TER. However, the drier conditions in the semi-arid regions, such as the Sahel, South Africa, and Australia, restricted this increase in TER induced by warmer temperatures (Fig. 6d). Higher air temperatures over North America largely enhanced the GPP and TER, while cooler conditions over the Eurasia reduced them (Fig. 6b–d). Wetter conditions over parts of North America and Eurasia also increased the GPP and TER to some extent (Fig. 6a).
Figure 7Spatial anomalies in (a) the simulated GPP by VEGAS (units: $\mathrm{g}\phantom{\rule{0.125em}{0ex}}\mathrm{C}\phantom{\rule{0.125em}{0ex}}{\mathrm{m}}^{-\mathrm{2}}\phantom{\rule{0.125em}{0ex}}{\mathrm{yr}}^{-\mathrm{1}}$), (b) the simulated leaf area index (LAI; units: m2 m−2), (c) solar-induced chlorophyll fluorescence (SIF; units: $\mathrm{mW}\phantom{\rule{0.125em}{0ex}}{\mathrm{m}}^{-\mathrm{2}}\phantom{\rule{0.125em}{0ex}}{\mathrm{nm}}^{-\mathrm{1}}\phantom{\rule{0.125em}{0ex}}{\mathrm{sr}}^{-\mathrm{1}}$), and (d) MODIS enhanced vegetation index (EVI, $×{\mathrm{10}}^{-\mathrm{2}}$) from July 2015 to October 2016.
Comparing the composite results (Fig. 6a–d) and the 1997/98 El Niño (Fig. 6e–h), the regional patterns were almost identical, except for the difference in magnitude. In contrast, there were some differences in the 2015/16 El Niño. Over the Sahel and East Africa, the soil wetness increased due to the higher precipitation (Fig. 6i), dynamically cooling the air temperature (Fig. 6k). These wetter conditions largely benefit GPP (Fig. 6j), compensating for the reduced GPP over the other tropical regions. This caused GPP to be near neutral in the tropics, as compared to the composite and the 1997/98 El Niño (Table 2). Higher soil moisture also contributed to increased TER over the Sahel (Fig. 6l), contrary to that in the 1997/98 El Niño (Fig. 6h). This spatial compensation in GPP, together with the widespread increase in TER, accounted for the TER dominance in the tropics during the 2015/16 El Niño. Furthermore, the higher GPP resulted in the anomalous carbon uptake in that region (Fig. 5c), which partly compensated for the anomalous carbon release over the other tropical regions. This in part caused the smaller tropical FTA during the 2015/16 El Niño compared with that during 1997/98. Another clear difference occurred over the Eurasia, with almost opposite signals during the 1997/98 and 2015/16 El Niño events. During the 2015/16 El Niño over the Eurasia, air temperature was anomalously higher compared with the cooling in the composite and during the 1997/98 El Niño (Fig. 6c, g, and k). This warmth enhanced the GPP and TER (Fig. 6j and l), as compared with the reduced levels in the composite and during the 1997/98 El Niño (Fig. 6b, d, f, and h). This phenomenon explains the stronger GPP and TER anomalies, and the anomalous carbon uptake over the whole of the extratropical Northern Hemisphere (Table 2).
Recently, more attention has been paid to SIF as an effective indicator of GPP (Guanter et al., 2014). Therefore, we compared the simulated GPP and SIF variabilities on the interannual timescale. Although noisy signals in SIF occurred, it was anomalously positive over the USA, parts of Europe, and East Africa, and negative over the Amazon and South Asia, during the 2015/16 El Niño, corresponding to increased and decreased GPP, respectively (Fig. 7a and c). The match over other regions was not significant. In addition, MODIS EVI increased anomalously over North America, southern South America, parts of Europe, the Sahel, and East Africa but reduced over the Amazon, northern Canada, central Africa, South Asia, and northern Australia (Fig. 7d). These EVI anomalies corresponded well with the simulated LAI anomalies (Fig. 7b). The good match between the simulated GPP (LAI) and SIF (EVI) gives us more confidence in the VEGAS simulations.
Figure 8FTA anomalies induced by wildfires. (a) Total global anomalies (Pg C yr−1). The dashed gray and solid black lines represent the anomalies simulated by VEGAS, detrended and smoothed by Butterworth filtering, respectively. The dashed and solid blue lines represent the GFED results. (b) Spatial FTA anomaly ($\mathrm{g}\phantom{\rule{0.125em}{0ex}}\mathrm{C}\phantom{\rule{0.125em}{0ex}}{\mathrm{m}}^{-\mathrm{2}}\phantom{\rule{0.125em}{0ex}}{\mathrm{yr}}^{-\mathrm{1}}$) during the 1997/98 El Niño in VEGAS. (c) Spatial FTA anomaly during the 2015/16 El Niño in VEGAS. (d) GFED anomaly during the 1997/98 El Niño episode.
Finally, wildfires, as important disturbances for FTA, always release carbon flux. Although the FTA anomalies caused by wildfires were generally smaller than the GPP or TER anomalies, they played an important role during the 1997/98 El Niño (globally, 0.42 Pg C yr−1 in VEGAS and 0.82 Pg C yr−1 in GFED; Table 2), which is consistent with previous work (van der Werf et al., 2004). The FTA anomalies caused by wildfires are shown in Fig. 8. The correlation coefficients between the simulated global FTA anomalies caused by wildfires and the GFED fire data product was 0.46 (unsmoothed) and 0.63 (smoothed; Fig. 8a), confirming that VEGAS has certain capability in simulating this disturbance. During the 1997/98 El Niño, satellite-based GFED data show that the FTA anomalies caused by wildfires mainly occurred over the tropical regions, such as the Amazon, central Africa, South Asia, and Indonesia (Fig. 8d). VEGAS also simulated the positive FTA over these tropical regions (Fig. 8b). The total tropical FTA anomalies caused by fires were 0.37 Pg C yr−1 in VEGAS and 0.72 Pg C yr−1 in GFED (Table 2). During the 2015/16 El Niño, wildfires also resulted in positive FTA anomalies over the Amazon, South Asia, and Indonesia; however, their magnitudes were smaller than those during the 1997/98 El Niño, because it was much drier during the 1997/98 event than the 2015/16 one (Fig. 6e and i). In addition, the wetter conditions over East Africa during the 2015/16 El Niño suppressed the occurrences of wildfires with the negative FTA anomalies (Fig. 8c). The total tropical FTA anomaly was 0.11 Pg C yr−1 in VEGAS (Table 2). Therefore, wildfires played a less important role during the 2015/16 event than during the 1997–98 one. The FTA anomalies caused by wildfires over the extratropics were much weaker than those over the tropics, and the match between VEGAS and GFED was poorer (Table 2; Fig. 8b and d).
4 Conclusions and discussion
The magnitudes and patterns of climate anomalies caused by different El Niño events differ. Therefore, the responses of terrestrial carbon cycle to different El Niño episodes remain uncertain (Schwalm, 2011). In this study, we compared in detail the impacts of two extreme El Niño events in recorded history (namely, the recent 2015/16, and earlier 1997/98 events) on the terrestrial carbon cycle in the context of a multi-event “composite” El Niño. We used VEGAS in its near-real-time framework, along with inversion datasets. The main conclusions can be summarized as follows:
• (1)
The simulations indicated that the global-scale FTA anomaly during the 2015/16 El Niño was 0.73 Pg C yr−1, which was nearly 2 times smaller than that during the 1997/98 El Niño (1.64 Pg C yr−1), and was confirmed by the inversion results. The FTA had no obvious lagged response during the 2015/16 El Niño, in contrast to that during the 1997/98 El Niño. Separating the global fluxes, the fluxes in the tropics and the extratropical Northern Hemisphere were 1.12 and 0.52 Pg C yr−1 during the 2015/16 El Niño, respectively, whereas they were 1.70 and 0.05 Pg C yr−1 during the 1997/98 event. Tropical FTA anomalies dominated the global FTA anomalies during both extreme El Niño events.
• (2)
Mechanistic analysis indicates that anomalously wet conditions occurred over the Sahel and East Africa during the 2015/16 El Niño, resulting in the increase in GPP, which compensated for the reduction in GPP over the other tropical regions. In total, this caused a near-neutral GPP in the tropics (0.03 Pg C yr−1), compared with the composite analysis (0.54 Pg C yr−1) and the 1997/98 El Niño (0.73 Pg C yr−1). The spatial compensation in GPP and the widespread increase in TER (0.95 Pg C yr−1) explained the dominance of TER during the 2015/16 El Niño, compared with the GPP dominance during the 1997/98 event. The different biological dominance accounted for the phase difference in the FTA responses during the 1997/98 and 2015/16 El Niño events.
• (3)
Higher air temperatures over North America largely enhanced the GPP and TER during the 1997/98 and 2015–16 El Niño events. However, the air temperatures during the 2015/16 El Niño over the Eurasia were anomalously higher, compared with the cooling during the 1997/98 El Niño episode. These warmer conditions benefited the GPP and TER, accounting for the stronger GPP (1.90 Pg C yr−1) and TER (1.45 Pg C yr−1) anomalies and anomalous carbon uptake (0.52 Pg C yr−1) over the extratropical Northern Hemisphere during the 2015/16 El Niño.
• (4)
Wildfires, frequent in the tropics, played an important role in the FTA anomalies during the 1997/98 El Niño episode, confirmed by the VEGAS simulation and the satellite-based GFED fire product. However, the VEGAS simulation showed that the tropical FTA caused by wildfires during the 2015/16 El Niño was relatively smaller than that during the 1997/98 El Niño. This result was mainly because the tropical weather was much drier during the 1997/98 event than during the 2015–16 one.
It is important to keep in mind that the responses of the terrestrial carbon cycle to the El Niño events in this study were simulated using an individual DGVM (VEGAS), which, whilst highly consistent with the variations in the CGR and inversion results, carries uncertainties in terms of the regional responses because of, for example, its model structure, biological processes considered, and parameterizations. Of course, uncertainties exist in all of the state-of-the-art DGVMs. Fang et al. (2017) recently suggested that none of the 10 contemporary terrestrial biosphere models captures the ENSO-phase-dependent responses. If possible, we will quantify the inter-model uncertainties in regional responses of the terrestrial carbon cycle to El Niño events when the new round of TRENDY simulations (1901–2016) becomes available. Although we used three inversion datasets as reference for the VEGAS simulation in this study, they cover different periods. Importantly, there are also large uncertainties between the different atmospheric CO2 inversions because of their different prescribed priors, a priori uncertainties, inverse methods, and observational datasets (Peylin et al., 2013). Future atmospheric CO2 inversions may produce more accurate results based on more observational datasets, including surface and satellite-based observations.
Recently, more studies have pointed out that the 1997/98 El Niño evolved following the eastern Pacific El Niño dynamics, which depends on basin-wide thermocline variations, whereas the 2015/16 event additionally involves the central Pacific El Niño dynamics that rely on the subtropical forcing (Paek et al., 2017; Palmeiro et al., 2017). Therefore, it is necessary to investigate the different impacts of the eastern and central Pacific El Niño types (Ashok et al., 2007) on the terrestrial carbon cycle in the future. This may give us an additional insight into the contrasting responses of the terrestrial carbon cycle to the 1997/98 and 2015/16 El Niño events. We believe that doing so will contribute greatly to deepening our knowledge of present and future carbon cycle variations on the interannual timescales.
Data availability
Data availability.
In this study, all the datasets can be freely accessed. The Mauna Loa monthly CO2 records are available at https://www.esrl.noaa.gov/gmd/ccgg/trends/data.html (ESRL, 2018b). The ERSST4 Niño3.4 Index can be accessed from http://www.cpc.ncep.noaa.gov/data/indices/ersst4.nino.mth.81-10.ascii (NOAA, 2018). The CAMS and MACC inversions are available at http://apps.ecmwf.int/datasets/ (ECMWF, 2018). The CarbonTracker datasets can be found at https://www.esrl.noaa.gov/gmd/ccgg/carbontracker/ (ESRL, 2018a). The GFEDv4 global fire emissions are downloaded at https://doi.org/10.3334/ORNLDAAC/1293 (Randerson et al., 2017). Satellite SIF datasets are retrieved from https://avdc.gsfc.nasa.gov/pub/data/satellite/MetOp/GOME_F/ (GSFC, 2018). MODIS enhanced vegetation index (EVI) datasets are downloaded from https://lpdaac.usgs.gov/dataset_discovery/modis/modis_products_table/mod13c2_v006 (LP DAAC, 2018).
Competing interests
Competing interests.
The authors declare that they have no conflict of interest.
Acknowledgements
Acknowledgements.
We gratefully acknowledge the ESRL for the use of their Mauna Loa atmospheric CO2 records and CarbonTracker datasets; NOAA for the ERSST4 ENSO index; LSCE-IPSL for the CAMS and MACC inversion datasets; the Oak Ridge National Laboratory Distributed Active Archive Center for the GFEDv4 global fire emissions; NASA Goddard Space Flight Center for the SIF datasets; and the Land Processes Distributed Active Archive Center for the MODIS EVI datasets. This study was supported by the National Key R&D Program of China (grant no. 2016YFA0600204 and no. 2017YFB0504000), the Natural Science Foundation for Young Scientists of Jiangsu Province, China (grant no. BK20160625), and the National Natural Science Foundation of China (grant no. 41605039).
Edited by: Somnath Baidya Roy
Reviewed by: two anonymous referees
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http://fallout.wikia.com/wiki/Carry_Weight
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# Carry Weight
17,658pages on
this wiki
Carry Weight
Fallout, Fallout 2, Fallout Tactics
modifiesInventory capacity
governed byStrength
initial value25 + (ST x 25) = lbs
related perksPack Rat, Strong Back
related traitsSmall Frame
Fallout 3, Fallout: New Vegas
modifiesInventory capacity
governed byStrength
initial value150 + (ST x 10) = lbs
related perksHeavyweight, Long Haul, Pack Rat, Strong Back
Van Buren
modifiesInventory capacity
governed byStrength
initial value?
related perks?
related traits?
J.E. Sawyer's Fallout RPG
modifiesInventory capacity
governed byStrength
initial value(ST + 6) * 25
related perks?
related traits?
...
The maximum amount of equipment your character can carry, in pounds.
— in-game description, Fallout
Carry Weight is a derived statistic in the SPECIAL system.
## Fallout, Fallout 2 and Fallout TacticsEdit
Your character will become slower as more weight is put on. When your character reaches the maximum weight, he or she becomes completely weighed down and cannot move until the weight is back under control.
$\text{Initial level}=25+(\text{Strength}\times25)$
Example: A starting Strength of 5.
$25+(5\times25)=150~\text{lbs}$
### NotesEdit
$\text{Initial level}=25+(\text{Strength}\times15)$
## Fallout 3 and Fallout: New VegasEdit
Movement speed is unaffected by your character's Carry Weight until the weight of items carried exceeds your total carry weight, at which point your character will become overencumbered and unable to run, jump, or fast travel, with the exception of the Long Haul perk in New Vegas.
$\text{Initial level}=150+(\text{Strength}\times10)$
Example: A starting Strength of 5.
$150+(5\times10)=200~\text{lbs}$
### NotesEdit
• Every added point of Strength increases your weight limit by 10 lbs.
• The maximum initial level is capped at 250 lbs without the addition of extra perks.
• The Strong Back perk increases the limit by 50 lbs.
• The Burden to Bear perk can increase this limit by another 50 lbs.
• The Hoarder trait increases the limit by 25 lbs.
• The NCR Courier duster increases carry weight by another 25 lbs.
• Buffout can temporarily increase this limit by another 20 lbs per dose, provided that you have 8 or less Strength points.
• In Fallout: New Vegas, the maximum amount of weight you can carry is 400 lbs.
• Using the console command "player.modav" carry weight can be increased to a max of 20,106 lbs.
• If you have the Long Haul perk in New Vegas, you can still fast-travel while over-encumbered.
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http://mathhelpforum.com/algebra/168747-non-linear-simultaneous-equation-print.html
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# Non-Linear Simultaneous Equation
• Jan 19th 2011, 03:07 AM
sxsniper
Non-Linear Simultaneous Equation
Hello,
I've just started on Non-linears and am Stuck on my first problem.
Heres the equations:
x^2 + y^2 =13
y = x+1
This is how far I've got, I would appreciate it if someone could show me where I'm going wrong.
• x^2 + (x+1)(x+1) = 13
• x^2 + (x^2+x+x+1) =13
• 2x^2 + 2x + 1 = 13
• 2x^2 + 2x -12 = 0
• x^2 + x -6 = 0
Now I'm stuck.
I've done this over and over and keep getting x^2=3 yet I know it should be x=2
• Jan 19th 2011, 03:15 AM
jacs
That looks good so far, now you need to factorise the quadratic to solve for x, you should get two solutions:
$x^2+x-6=0$
(x - 2)(x + 3) = 0
x = 2, x = -3
then from there substitute both in to find your respective y values
• Jan 19th 2011, 04:47 AM
sxsniper
Nice, of course it is! Thanks.
The answers should come out as x = 2 and y = -3
However if I put this in to the second equation y=x+1
Then y = 2+1 which is 3, not -3.
What's the deal with that?
I have a serious issue with +s and -s.
Are the answers I was given wrong?
If I put it in the first:
x^2 + y^2 = 13 so;
• 2^2 + -3^2 = 13
• 4 + -9 = -3 ...which isn't 13!
I know +9 makes 13, but WHY does -3^2 = 9?! as -3^3 = -27.
I think I'm missing some serious basic maths.
If I am, any suggestions on things I should practice or learn?
I was stuck straight in the top set at school, and was rarely taught the basics, just throw straight in to the difficult things.
EDIT:
OK now I understand a - * - = +
That still doesn't answer why "y = 2+1 is 3, not -3.
• Jan 19th 2011, 06:28 AM
HallsofIvy
Quote:
Originally Posted by sxsniper
Nice, of course it is! Thanks.
The answers should come out as x = 2 and y = -3
NO, x= 2 and y= -3 can't be the correct answer: it does not satisfy the second equation y= x+ 1.
I suspect you have misunderstood what is given as the two correct answers. From the quadratic equation you got, x= 2 or x= -3. Then from y= x+ 1, y= 2+1= 3 or y= -3+ 1= -2. The two answers to the problem are "x= 2 and y= 3" and "x= -3 and y= -2".
Quote:
However if I put this in to the second equation y=x+1
Then y = 2+1 which is 3, not -3.
What's the deal with that?
x= 2, y= -3 is NOT a correct answer!
[quote]I have a serious issue with +s and -s.
Are the answers I was given wrong?
If I put it in the first:
x^2 + y^2 = 13 so;
• 2^2 + -3^2 = 13
• 4 + -9 = -3 ...which isn't 13!
You have written the second equation incorrectly- all of y is squared:
$2^2+ (-3)^2= (2)(2)+ (-3)(-3)= 4+ 9= 13$
Oh, by the say, 4- 9 is not -3, either, it is -5.
Quote:
I know +9 makes 13, but WHY does -3^2 = 9?! as -3^3 = -27
I think I'm missing some serious basic maths.
Again, it is NOT "-3^2"- the negative is as much part of y as the "3" is: (-3)^2= (-3)(-3)= +9.
Quote:
If I am, any suggestions on things I should practice or learn?
I was stuck straight in the top set at school, and was rarely taught the basics, just throw straight in to the difficult things.
EDIT:
OK now I understand a - * - = +
That still doesn't answer why "y = 2+1 is 3, not -3.
I hope you don't mean exactly what you are writing here. If you have 2 banana cream pies on the table and put one more banana cream pie on the table, you have three banana cream pies, not negative three!
• Jan 19th 2011, 08:03 AM
sxsniper
That's my point, on the answers page, it says -3
• Jan 19th 2011, 08:56 AM
sxsniper
Ahhh, you know I've been trying to solve this for about 8 hours flat now.
Bloody answers page must be wrong, I got 3 plenty of times! And was scratching my eye balls out trying to figure out WHY oh WHY am I not getting -3.
Thank yooou.
• Jan 19th 2011, 10:07 AM
Wilmer
Want some practice? Try:
a^2 + b^2 + c^2 = 142
b = a + 1
c = 2a - 1
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https://kb.osu.edu/dspace/handle/1811/31041
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# CONFORMATIONAL ISOMERISM IN 1-HEPTANAL
Please use this identifier to cite or link to this item: http://hdl.handle.net/1811/31041
Files Size Format View
abstract.gif 21.02Kb GIF image
Title: CONFORMATIONAL ISOMERISM IN 1-HEPTANAL Creators: Fisher, Jonathan; Xu, Li-Hong; Suenram, R. D.; Pate, Brooks H.; Douglass, Kevin O. Issue Date: 2006 Publisher: Ohio State University Abstract: \hspace{1cm} The rotational spectrum of 1-heptanal (CH$_3$-CH$_2$-CH$_2$-CH$_2$-CH$_2$-CH$_2$-CH=O) has been recorded over the 10 GHz to 22 GHz region using a pulsed-molecular-beam, Fourier transform microwave spectrometer. The spectrum has been analyzed using the jb95$^{[1]}$ spectral analysis program. The spectra of thirteen conformational isomers have been identified and assigned in the rich soup of observed transitions. Transitions of these isomers have relative intensities that are well above the intensity level of the onset of $^{13}$C isotopomers, which are a factor of 100 down in intensity. In addition to the above 13 isomers, two additional spectra were identified and assigned that belong to dimers that consist of 1-heptanal and one water molecule. In order to map the observed spectra to conformational geometries, high-level ${ab initio}$ calculations have been carried out. All fifteen observed conformers have been associated with ${ab initio}$ determined structure configurations. In general, the agreement in rotational constants and dipole intensity pattern between the ${ab initio}$ results and the experimentally observed spectra is quite good. \hrule \hspace{1cm} \item{$^{[1]}$} http://physics.nist.gov/Divisions/Div844/facilities/uvs/jb95userguide.htm Description: Author Institution: Centre for Laser, Atomic and Molecular Sciences (CLAMS), Dept. of Physical Sciences, Univ. of New Brunswick, Canada E2L 4L5; Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8441; Dept. of Chemistry, University of Virginia, Charlottesville, VA 22904-4319 URI: http://hdl.handle.net/1811/31041 Other Identifiers: 2006-RI-13
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https://etoobusy.polettix.it/2022/04/12/pwc160-four-is-magic/
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TL;DR
Here we are with TASK #1 from The Weekly Challenge #160. Enjoy!
# The challenge
You are given a positive number, $n < 10. Write a script to generate english text sequence starting with the English cardinal representation of the given number, the word ‘is’ and then the English cardinal representation of the count of characters that made up the first word, followed by a comma. Continue until you reach four. Example 1: Input:$n = 5
Output: Five is four, four is magic.
Example 2:
Input: $n = 7 Output: Seven is five, five is four, four is magic. Example 3: Input:$n = 6
Output: Six is three, three is five, five is four, four is magic.
# The questions
Apart from the usual nitpick about numbers meaning integers, I’m curious about the restriction to numbers below 10. Is it just kindness?
Another question: are there other fixed points in addition to four?
# The solution
I was initially planning on getting a generic function for whatever positive input, or negative for what’s it’s worth, but time pressure steered me to just address the task at hand. So we’re doing it in the safe way: spell all digits loud, iterate until we find four, and format our outputs according to the examples.
Raku goes first:
#!/usr/bin/env raku
use v6;
sub MAIN (Int:D $n where 0 < * < 10 = 5) { put four-is-magic($n); }
sub four-is-magic (Int:D $n is copy where 0 < * < 10) { state @ints = <zero one two three four five six seven eight nine >; my$current = @ints[$n]; my @seq = gather while$n != 4 {
$n =$current.chars;
my $next = @ints[$n];
take "$current is$next";
$current =$next;
};
@seq.push: 'four is magic.';
@seq[0] = @seq[0].tclc;
return @seq.join(', ');
}
Then, of course, Perl:
#!/usr/bin/env perl
use v5.24;
use warnings;
use experimental 'signatures';
no warnings 'experimental::signatures';
my $n = shift // 7; say four_is_magic($n);
sub four_is_magic ($n) { state$ints = [qw< zero one two three four five six seven eight nine >];
my $current =$ints->[$n]; my @seq; while ($n != 4) {
$n = length$current;
(my $previous,$current) = ($current,$ints->[$n]); push @seq, "$previous is $current"; } push @seq, 'four is magic.';$seq[0] = ucfirst \$seq[0];
return join ', ', @seq;
}
Stay safe!
|
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|
https://www.cs.princeton.edu/courses/archive/fall18/cos226/assignments/8puzzle/specification.php
|
Write a program to solve the 8-puzzle problem (and its natural generalizations) using the A* search algorithm.
The problem. The 8-puzzle is a sliding puzzle that is played on a 3-by-3 grid with 8 square tiles labeled 1 through 8, plus a blank square. The goal is to rearrange the tiles so that they are in row-major order, using as few moves as possible. You are permitted to slide tiles either horizontally or vertically into the blank square. The following diagram shows a sequence of moves from an initial board (left) to the goal board (right).
Board data type. To begin, create a data type that models an n-by-n board with sliding tiles. Implement an immutable data type Board with the following API:
public class Board {
// create a board from an n-by-n array of tiles,
// where tiles[row][col] = tile at (row, col)
public Board(int[][] tiles)
// string representation of this board
public String toString()
// tile at (row, col) or 0 if blank
public int tileAt(int row, int col)
// board size n
public int size()
// number of tiles out of place
public int hamming()
// sum of Manhattan distances between tiles and goal
public int manhattan()
// is this board the goal board?
public boolean isGoal()
// does this board equal y?
public boolean equals(Object y)
// all neighboring boards
public Iterable<Board> neighbors()
// is this board solvable?
public boolean isSolvable()
// unit testing (required)
public static void main(String[] args)
}
Constructor. You may assume that the constructor receives an n-by-n array containing a permutation of the n2 integers between 0 and n2 − 1, where 0 represents the blank square. You may also assume that 2 ≤ n ≤ 32,768.
String representation. The toString() method returns a string composed of n + 1 lines. The first line contains the board size n; the remaining n lines contains the n-by-n grid of tiles in row-major order, using 0 to designate the blank square.
Tile extraction. Throw a java.lang.IllegalArgumentException in tileAt() unless both row and col are between 0 and n − 1.
Hamming and Manhattan distances. To measure how close a board is to the goal board, we define two notions of distance. The Hamming distance betweeen a board and the goal board is the number of tiles in the wrong position. The Manhattan distance between a board and the goal board is the sum of the Manhattan distances (sum of the vertical and horizontal distance) from the tiles to their goal positions.
Comparing two boards for equality. Two boards are equal if they are have the same size and their corresponding tiles are in the same positions. The equals() method is inherited from java.lang.Object, so it must obey all of Java’s requirements.
Neighboring boards. The neighbors() method returns an iterable containing the neighbors of the board. Depending on the location of the blank square, a board can have 2, 3, or 4 neighbors.
Detecting unsolvable boards. An efficient approach for detecting unsolvable boards is described in the next section.
Unit testing. Your main() method must call each public method directly and help verify that they works as prescribed (e.g., by printing results to standard output).
Performance requirements. In the worst case, your implementation must support size(), tileAt(), isGoal(), hamming(), and manhattan() in constant time; the constructor, equals(), toString(), and neighbors() in time proportional to n² (or better); and isSolvable() in time proportional to n4 (or better). See the optimizations section for information on making hamming() and manhattan() take constant time.
Detecting unsolvable boards. Not all initial boards can lead to the goal board by a sequence of moves, including these two:
Remarkably, we can determine whether a board is solvable without solving it! To do so, we count inversions, as described next.
• Inversions. Given a board, an inversion is any pair of tiles i and j where i < j but i appears after j when considering the board in row-major order (row 0, followed by row 1, and so forth).
• Odd-sized boards. First, we’ll consider the case when the board size n is an odd integer. In this case, each move changes the number of inversions by an even number. Thus, if a board has an odd number of inversions, it is unsolvable because the goal board has an even number of inversions (zero).
It turns out that the converse is also true: if a board has an even number of inversions, then it is solvable.
In summary, when n is odd, an n-by-n board is solvable if and only if its number of inversions is even.
• Even-sized boards. Now, we’ll consider the case when the board size n is an even integer. In this case, the parity of the number of inversions is not invariant. However, the parity of the number of inversions plus the row of the blank square (indexed starting at 0) is invariant: each move changes this sum by an even number.
That is, when n is even, an n-by-n board is solvable if and only if the number of inversions plus the row of the blank square is odd.
A* search. Now, we describe a solution to the 8-puzzle problem that illustrates a general artificial intelligence methodology known as the A* search algorithm. We define a search node of the game to be a board, the number of moves made to reach the board, and the previous search node. First, insert the initial search node (the initial board, 0 moves, and a null previous search node) into a priority queue. Then, delete from the priority queue the search node with the minimum priority, and insert onto the priority queue all neighboring search nodes (those that can be reached in one move from the dequeued search node). Repeat this procedure until the search node dequeued corresponds to the goal board.
The efficacy of this approach hinges on the choice of priority function for a search node. We consider two priority functions:
• The Hamming priority function is the Hamming distance of a board plus the number of moves made so far to get to the search node. Intuitively, a search node with a small number of tiles in the wrong position is close to the goal, and we prefer a search node if has been reached using a small number of moves.
• The Manhattan priority function is the Manhattan distance of a board plus the number of moves made so far to get to the search node.
To solve the puzzle from a given search node on the priority queue, the total number of moves we need to make (including those already made) is at least its priority, using either the Hamming or Manhattan priority function. Why? Consequently, when the goal board is dequeued, we have discovered not only a sequence of moves from the initial board to the goal board, but one that makes the fewest moves. (Challenge for the mathematically inclined: prove this fact.)
Game tree. One way to view the computation is as a game tree, where each search node is a node in the game tree and the children of a node correspond to its neighboring search nodes. The root of the game tree is the initial search node; the internal nodes have already been processed; the leaf nodes are maintained in a priority queue; at each step, the A* algorithm removes the node with the smallest priority from the priority queue and processes it (by adding its children to both the game tree and the priority queue).
For example, the following diagram illustrates the game tree after each of the first three steps of running the A* search algorithm on a 3-by-3 puzzle using the Manhattan priority function.
Solver data type. In this part, you will implement A* search to solve n-by-n slider puzzles. Create an immutable data type Solver with the following API:
public class Solver {
// find a solution to the initial board (using the A* algorithm)
public Solver(Board initial)
// min number of moves to solve initial board
public int moves()
// sequence of boards in a shortest solution
public Iterable<Board> solution()
// test client (see below)
public static void main(String[] args)
}
Implementation requirement. To implement the A* algorithm, you must use the MinPQ data type for the priority queue.
Corner case. Throw a java.lang.IllegalArgumentException in the constructor if the argument is null.
Unsolvable boards. Throw a java.lang.IllegalArgumentException in the constructor if the initial board is not solvable.
Test client. Your test client should take the name of an input file as a command-line argument and print the minimum number of moves to solve the puzzle and a corresponding solution. The input file contains the board size n, followed by the n-by-n grid of tiles, using 0 to designate the blank square.
~/Desktop/8puzzle> more puzzle04.txt 3 0 1 3 4 2 5 7 8 6 ~/Desktop/8puzzle> java-algs4 Solver puzzle04.txt Minimum number of moves = 4 3 0 1 3 4 2 5 7 8 6 3 1 0 3 4 2 5 7 8 6 3 1 2 3 4 0 5 7 8 6 3 1 2 3 4 5 0 7 8 6 3 1 2 3 4 5 6 7 8 0 ~/Desktop/8puzzle> more puzzle3x3-unsolvable.txt 3 1 2 3 4 5 6 8 7 0 Unsolvable puzzle
Two optimizations. To speed up your solver, implement the following two optimizations:
• The critical optimization. A* search has one annoying feature: search nodes corresponding to the same board are enqueued on the priority queue many times (e.g., the bottom-left search node in the game-tree diagram above). To reduce unnecessary exploration of useless search nodes, when considering the neighbors of a search node, don’t enqueue a neighbor if its board is the same as the board of the previous search node in the game tree.
• Caching the Hamming and Manhattan distances. To avoid recomputing the Hamming and Manhattan distances of a board from scratch each time during various priority-queue operations, precompute the values in the Board constructor; save them in instance variables; and return the saved values as needed. This caching technique is broadly applicable: consider using it in any situation where you are recomputing the same quantity many times and for which computing that quantity is a bottleneck operation.
Challenge for the bored. Implement a better solution which is capable of solving puzzles that the required solution is incapable of solving.
Deliverables. Submit the files Board.java and Solver.java (with the Manhattan priority). We will supply algs4.jar. Your may not call any library functions other than those in java.lang, java.util, and algs4.jar. You must use MinPQ for the priority queue. Finally, submit a readme.txt file and answer the questions.
Board.java 15
Solver.java 20
readme.txt 5
|
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|
http://mathhelpforum.com/differential-equations/165071-solving-substituting-complex-function-2.html
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That's the chain rule. If you want to simplify the notation, do a quick z = dy/dx substitution, and you'll see how it works out.
|
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|
https://dummylabs.com/post/2019-01-13-influxdb-part1/
|
# InfluxDB and Home Assistant (Part 1)
In this post, I’d like to share my experience with InfluxDB as a long term storage and visualization facility for Home Assistant data. It also covers centralized logging, monitoring, and automatic error notifications. The article consists of three parts:
1. Installation of InfluxDB as Hass.io addon, using Grafana for data visualization, embedding graphs into a Lovelace card (this post)
2. Using Telegraf to collect various system metrics (e.g. CPU load and memory usage for all Docker containers both created by Hass.io and your own, RAID disks temperature, etc.). This part will also cover memory-effective storage of everlasting data in InfluxDB which you want to keep forever.
3. Part 3 will discuss centralized logging for any Docker containers in your setup, as well as for any device utilizing Syslog protocol (including ESP** microcontrollers with Tasmota and ESPEasy firmware). This part will also include anomaly detection and severe error notifications (e.g. notification can be sent if the same error occurs more than 5 times in an hour).
• Very small memory footprint and CPU requirements compared to Elastic Search. Worth to say that InfluxDB runs very well on a Raspberry Pi
• It is possible to keep important data as long as you want to, without performance impact using so-called Continuous Queries (they will be described in part 2). If you’re using SQLite with Home Assistant, increasing number of days may slow down your system especially if you run it on an ARM board
• It works well with Grafana, very beautiful dashboard tool for time-series data. The Hass.io add-on also includes a similar tool named Chronograf
• InfluxDB can work with native agent Telegraf (a tiny and fast command line utility) which may send the huge amount of metrics from your systems to InfluxDB using an extensive list of plugins
• Monitoring and anomaly detection service named Capacitor is also included to InfluxDB addon. It can notify the user when bad things happen using various communication means, including MQTT.
InfluxDB is a mature time-series DB presented in 2013. Time-series means that it is optimized for chunks of data, where each chunk contains a timestamp. Examples of such data are CPU load, network speed, disk temperature or memory consumption. InfluxDB is written in Go, a modern programming language with static linking which produces one compact executable file with no dependencies. This made it possible to handle the huge amount of data with very small memory and CPU requirements. I have been using InfluxDB for a long time on a 512Mb droplet along with additional services without any problems. When I decided to give Elastic Search a try, I found myself struggling at 100% memory usage along with 100% CPU usage. Yes, you can try to tune up Elastic Search with the JVM settings, but anyway, it really loves your RAM.
## InfluxDB Basic Terminology
If you ready to rely on InfluxDB and use it as your data storage, it makes sense to learn at least basic terminology and concepts behind it.
The full list of definitions can be found on InfluxDB site, we will cover only those which may be necessary while playing with data stored by Home Assistant. Below is the sample data for my temperature sensor named sensor.bedroom_temperature.
Timestamp domain entity_id friendly_name_str value
2019-01-09T21:19:00.314567936Z sensor bedroom_temperature Bedroom Temperature 20.5
2019-01-09T21:20:00.332456192Z sensor bedroom_temperature Bedroom Temperature 20.4
2019-01-09T21:23:00.390132992Z sensor bedroom_temperature Bedroom Temperature 20.3
2019-01-09T21:25:00.430054912Z sensor bedroom_temperature Bedroom Temperature 20.4
2019-01-09T21:28:00.485129984Z sensor bedroom_temperature Bedroom Temperature 20.3
### Retention Policy
A retention policy defines how long the data will be stored on disk (e.g. 7 days or infinite). It also defines some cluster parameters which are irrelevant for this article. Each database in InfluxDB is associated with an automatically generated retention policy named autogen. Most of the times when you picking up a database in Capacitor UI or issuing an InfluxQL query, the database name is used together with retention policy name separated by a dot, e.g. home_assistant.autogen.
### Database
Database contains data from Home Assistant sensors and other entities. The duration how long the data is available is defined by a retention policy. By default, Home Assistant component InfluxDB stored its data in the database named home_assistant, but in general InfluxDB can keep as many databases as you need.
### Timestamp
Timestamp is the date and time when some sensor values were captured. All data stored in InfluxDB should contain timestamp by design. Timestamps are always stored in UTC and can be converted to local time using client time zone settings.
### Field
Any pair of key and value for your sensor data. In the above table, fields are value and friendly_name_str. As said above, each field is associated with a timestamp.
### Tag
In the above table, tags are domain and entity_id. Tags are text fields which may contain limited set of values. These fields are internally indexed and therefore can be queried very fast.
### Measurement
Measurement is a way to keep different sets of tags, fields, and timestamps separated. Sounds complicated, but this is a simple concept which allows having multiple named datasets within a database. By default, InfluxDB HA component creates a measurement for temperature sensors, a measurement for humidity sensors, a measurement for data without a unit of measure, etc. This behavior can be redefined by override_measurement parameter of component configuration). Each measurement can be associated with one or many retention policies.
Let’s check what measurements are in my database home_assistant:
> show measurements
name: measurements
name
----
binary
downsampled_temp
energy
humidity
temperature
There are three measurements, some of them named after the units of measure reported by sensors and one is state which contains values of entities without units, e.g. switches. Storing all unitless values in the state measurement is imposed by default_measurement parameter of InfluxDB HA component configuration.
One of the useful applications of measurements is to store the data with different lifetime requirements in different measurements. Data downsampled to one-hour interval will hold 60 times less disk space than data stored minutely. This approach will be discussed in the second part of this article.
## Installation and Configuration
The easiest way to install InfluxDB is a community addon available for Hass.io. Advanced users can try to install InfluxDB manually using the official guide or utilize one of ready to use containers from the Docker hub. One of the advantages of Hass.io is that the system will automatically select proper addon architecture for you based on your hardware setup (ARM or x86).
In order to install the addon, open Hass.io->ADD-ON STORE tab and make sure that Community Hass.io Add-ons is present.
If it is not present, just put the following URL into Add new repository by URL field: https://github.com/hassio-addons/repository When the URL is added, a new section named Community Hass.io Add-ons should appear in the list of plugins. Select and install InfluxDB addon:
When the addon is installed, modify its configuration as given below and restart the addon:
{
"log_level": "error",
"auth": true,
"reporting": false,
"ssl": false,
"certfile": "",
"keyfile": ""
}
Thanks to Ingress technology, introduced in Home Assistant 0.91.3, we don’t need to mess around the ports and configuration changes for iframe embedding - this all is done by a single switch named Show in sidebar. This super technology also makes unnecessary to enter login and password for InfluxDB authentication.
### Create a User and the Database
We need to create a user and the database in InfluxDB to make data flow. Open the InfluxDB web UI (named Chronograf), select InfluxDB Admin->Users->Create user from the left menu. Assign “ALL” permissions to the user.
The next step is the database. By default InfluxDB component for Home Assistant uses the database surprisingly named home_assistant, this can be redefined in configuration.yaml. Open Databases tab and create our DB:
For Duration I usually pick the 7-day option, this is enough for troubleshooting. The long term data require another approach to reduce its size and frequency, we will see how to keep such data forever in the part 2.
### Home Assistant Configuration
Add the following section to configuration.yaml
influxdb:
max_retries: 3
default_measurement: state
include:
entities:
- sensor.bedroom_humidity
- sensor.bedroom_temperature
include section contains which HA entities we would like to persist in our database. A detailed description of component configuration is given here: https://www.home-assistant.io/components/influxdb/
default_measurement option defines the name of measurement, which is used for data from entities without a unit of measurements, e.g. switches state.
override_measurement option allows keeping all Home Assistant data in one measurement with given name. It may be convenient to use something like temperature instead of °C when you have to perform manual queries.
### When does it matter
This is an optional step and may be skipped especially if you have no plans to create Continues Queries and will use visual query constructors like Grafana or Capacitor. But if you going to try CQs in the future, it’s worth to configure InfluxDB component in a right way.
### Problem Description
By default, the measurements in InfluxDB named after units of measurements from Home Assistant. As example, humidity data will fall in % measurement, temperature data will be in °C or °F, etc. This seems to be quite inconvenient by different reasons:
• when writing InfluxDB query by hand, you will need to copy special characters like ° as you cannot enter them by keyboard, characters like % should be escaped to avoid query parser errors
• data with different meaning but same units of measurements may fall into one measurement, e.g. humidity value and battery status
• data without units (switches, counters, etc) either fall to the default measurement or to the measurement named after entity name
Hopefully measurement names can be customized in a few ways, for an entity like specific sensor with its own ID, for domains like sensor and globally for all HA entities. InfluxDB component documentation briefly mentions that but contains no extra details (at the moment of writing). Luckily I found a PR on the github which contains enough details to sort it out.
In the example below we assign lt measurement for a specific entity counter.hotw. This is defined in component_config section. Additionally we specify that the data from all entities with temperature at the end of their names should fall into temperature measurement. Global customizations are defined in component_config_glob section:
influxdb:
max_retries: 3
default_measurement: state
include:
entities:
- sensor.bedroom_humidity
- sensor.bedroom_temperature
component_config:
counter.hotw:
override_measurement: lt
component_config_glob:
sensor.*humidity:
override_measurement: humidity
sensor.*temperature:
override_measurement: temperature
### Verify That Data Flows
Let’s check that InfluxDB keeps our data. Open its Web UI and go to Explore tab. Select home_assistant.autogen from the list of databases in the bottom left. As it said before, autogen prefix is the name of the default retention policy associated with the DB.
We should see some values like (%, °C, state, etc.) in the list named Measurements & Tags. Or, if customization rules were defined, measurement names will be like temperature, humidity, lt. If we click temperature for instance, the nested list will give us all tags associated with this measurement. You want entity_id as it refers to a sensor identifier from Home Assistant. Click on entity_id and you should see your sensor ids (mine is bedroom_temperature).
Click on Submit Query button. You should see your data now:
## Install Grafana
With all due respect to InfluxData talented team, their Chronograf still lacks some essential features. I haven’t found ability to use two Y axis (it is useful to combine temperature and humidity into one diagram). I also missed embed feature which allows using these graphs in Lovelace. The latter was announced, but I did not manage to find any information on how to use it. So we have to install Grafana.
{
"log_level": "error",
"ssl": false,
"certfile": "",
"keyfile": "",
"plugins": [],
"env_vars": []
}
Hit Save and restart addon, now it is ready to use. But first, we have to do some initial configuration:
1. Log in to InfluxDB and create Grafana user or stick to an existing user
2. Log in into Grafana using admin/hassio credentials. Then create a new data source (Configuration->Data Sources->Add Data Source)
3. Choose InfluxDB as the data source type
4. Data source creation dialog should appear. Fill in arbitrary data source name in the Name field
5. Copy and paste http://a0d7b954-influxdb:8086 into URL field (this is the internal name of the addon docker container within the Hass.io Docker network)
6. Put into InfluxDB details Home Assistant database name, username, and password.
Rest of the fields should remain unchecked. Hit Save to save your configuration. Now it is time to create our first graph.
### Creating a Graph
1. Select + -> Create Dashboard -> Graph from the sidebar menu
2. In order to create a query, activate dropdown menu under Panel Title and Select Edit:
3. Query builder is at the bottom. Click select measurement choose the corresponding unit of measure, e.g. temperature. Select entity_id in WHERE clause and choose your sensor ID:
4. Select fill(none) in the GROUP BY field. You should see your temperature graph now.
5. Let’s add another type of data, say humidity (this is an optional step). In order to accomplish that click Add Query and repeat steps 1 and 2 with humidity measurement.
6. To tell Grafana that the values on the graph use different units of measure, click on colored thin line which is a part of the graph legend, a popup window should appear. Select Y Axis: Right
7. After changes are applied you should see something like that:
Let’s add this nice graph into a Lovelace card. We want card of iframe type:
- title: Indoor Climate
id: indoor-climate
cards:
- type: iframe
id: graf1
url: http://192.168.1.200:3000/d-solo/OGR_Smwik/new-dashboard-copy?panelId=2&orgId=1
aspect_ratio: 65%
In the URL property, we should specify Grafana panel URL. This one can be grabbed from Share dialog (it is available from the same popup menu where Edit is). When Share Panel popup appears, go to Embed tab. You should uncheck useless checkbox Current Time Range and copy URL from the edit box to your clipboard.
Let’s open Lovelace and enjoy the result:
You are awesome!
### Light Theme for Grafana
What is that? Didn’t you just say that dark theme is not perfect choice for default Lovelace color scheme? Hopefully, this can be fixed with ease. Add a parameter to Grafana URL &theme=light so that the final URL looks like:
http://192.168.1.200:3000/d-solo/e5Rz-eUmz/new-dashboard-copy?orgId=1&panelId=2&theme=light
Now it looks very good!
There is one more thing to improve: all sensor values fall in a very narrow range. For example, temperature delta is less than a degree Celsius. In order to make them look more useful, let’s set minimum and maximum values for both Y axes using common sense:
Don’t forget to save changes by this small button with 3.5” floppy disk image. Have no idea how this floppy might looks like? You’re welcome:
When the changes are saved, our diagram becomes less weird:
### Refresh Interval for Embedded Diagrams
Another useful parameter named refresh allows specifying refresh interval for our embedded panel. Add the following to refresh it every minute:
http://192.168.1.200:3000/d-solo/OGR_Smwik/new-dashboard-copy?panelId=2&orgId=1&theme=light&refresh=1m
### Specify Relative Time for Embedded Diagrams
There is a special control in Grafana UI to specify relative time for graph data:
An important point here is that this parameter can be set to any value from the Grafana UI and saved for a panel, but embedded diagram will always ignore it. There are two ways to specify relative time for an embedded graph:
1. Go to Time Range tab in the Graph Editor and fill in Override relative time, e.g. 8h and save changes. Refresh embedded graph and it should use specified time period.
2. Use special URL parameters as described in the ticket. Below is an example of URL which specify 8 hours time range (pay attention to from and to parameters):
http://192.168.1.200:3000/d-solo/OGR_Smwik/new-dashboard-copy?panelId=2&orgId=1&from=now-8h&to=now&refresh=5m&theme=light
Second approach gives us an opportunity to have several Lovelace cards with different resolution using the same URL. Or one can even cosider builing her own custom Lovelace card with time range switcher.
## Conclusion
We have learned how to store Home Assistant data in InfluxDB, create awesome diagrams with Grafana and embed them into nice looking Lovelace cards. Part 2 will cover InfluxDB Continuous Queries to effectively keep historical data for unlimited period of time with no significant performance impact. Also Telegraf agent will be discussed, which allows collecing various system metrics in InfluxDB. That’s it for the part 1, stay tuned!
|
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|
https://moodle.org/mod/forum/discuss.php?d=30886
|
## Themes
In trying to modify the xcss files I run into the following problem:
I cannot change color of the variable part of the logininfo.
In firefox I lookup the information of id's and class information. here I find that the logibn text is class: logininfo, but adding color: white here, onlyy changes the color of the fixed part: "you are logged in as"
Any suggestions??
Average of ratings: -
Martin, with
.logininfo {
color:#FFF
}
you change the text color. If you also want to change the color of the links you add
.logininfo a:link {
}
}
}
I hope this helps.
Urs
Average of ratings: -
Hi - I know you posted this way back! In which file should these additions go? I wish to change the 'Login' (or 'Logout' if already logged in!) link colour.
Regards...Peter
Average of ratings: -
Hi Peter,
CSS FAQ and Themes FAQ are good starting points.
You might even get fancy and try the following (see screenshot):
|
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|
https://danosproject.atlassian.net/wiki/spaces/DAN/pages/601489455/Access+Control+Management+ACM+and+Role-Based+Access+Control+RBAC
|
# Access Control Management (ACM) and Role-Based Access Control (RBAC)
Role-based Access Control (RBAC) is a method of restricting access to part of the configuration to authorized users. RBAC allows an administrator to define the rules for a group of users that restrict which commands users of that group are allowed to run.
RBAC is performed by first creating a group assigned to the Access Control Management (ACM) rule set, adding a user to the group, creating a rule set to match the group to the paths in the system, then configuring the system to allow or deny those paths that are applied to the group.
Users are allowed to be in one of three class of users with defined privilege levels:
• Operator—Allowed to execute commands that are defined in the DANOS CLI. Not allowed to into config mode.
• Administrator—Allowed to execute arbitrary Linux commands in addition to commands that are defined by the DANOS CLI and to enter configuration mode.
• Superuser—Allowed to execute commands with root privileges through the sudo command in addition to having administrator class privileges.
By default, all users that are defined to be in the superuser or the administrator class belong to a common group called vyattacfg. This group allows a rule set to be defined that pertains to both the superuser and administrator classes without defining two group matches. The operator class users belong to the vyattaop group.
DANOS allows a superuser to create new groups based on your requirements. We recommend creating a group with the highest level of privileges, called a security group. A superuser can set rules so that only members of the security group are allowed to modify the ACM and login information. This prevents administrators from inadvertently compromising the system image or the ACM list.
# Path matching
System configuration is modelled after a tree structure and enables the user to filter any path of that tree. The system supports only absolute addressing that begins with/as the root and uses the wildcard operator (*) as the path language.
Operational mode paths are absolute and do not match their children if a wildcard operator (*) is not included at the end of the path. Therefore, not using the wildcard operator restricts the user to specific commands.
In the following example, rule 1 restricts the use of the show command to only show interfaces and rule 2 denies all other show commands.
1 2 3 4 5 6 7 8 rule 1 { action allow path "/show/interfaces" } rule 2 { action deny path "/show/*" }
# Example of a rule set in operational mode
Operational mode has a rule set like the configuration mode that allows administrators to specify which operation mode commands a user is allowed to run. For example, as a protocol administrator, the user needs to execute only the show interfaces and show ip families of commands and, therefore, should not be allowed to run other administrative actions.
To define the operation mode rules for the protocol administrator group (protoadmin), perform the following steps in configuration mode.
Create a rule allowing all operations on /show/ip for the protoadmin group.
1 2 3 danos@R1# set system acm operational-ruleset rule 10 action 'allow' danos@R1# set system acm operational-ruleset rule 10 command '/show/ip/*' danos@R1# set system acm operational-ruleset rule 10 group 'protoadmin'
Create a rule allowing all operations on /show/interfaces for the protoadmin group.
1 2 3 danos@R1# set system acm operational-ruleset rule 20 action 'allow' danos@R1# set system acm operational-ruleset rule 20 command '/show/interfaces/*' danos@R1# set system acm operational-ruleset rule 20 group 'protoadmin'
Create a rule allowing all operations on /configure for the protoadmin group.
1 2 3 danos@R1# set system acm operational-ruleset rule 30 action 'allow' danos@R1# set system acm operational-ruleset rule 30 command '/configure' danos@R1# set system acm operational-ruleset rule 30 group 'protoadmin'
Deny all operations on all other paths for the protoadmin group.
1 2 3 danos@R1# set system acm operational-ruleset rule 40 action 'deny' danos@R1# set system acm operational-ruleset rule 40 command '*' danos@R1# set system acm operational-ruleset rule 40 group 'protoadmin'
The following example shows the operational mode rule set that is configured above.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 super@danos# show system acm operational-ruleset rule 10 { action allow command "/show/ip/*" group protoadmin } rule 20 { action allow command "/show/interfaces/*" group protoadmin } rule 30 { action allow command /configure group protoadmin } rule 40 { action deny command "*" group protoadmin }
The following example shows system login information regarding the protoadmin group with a user called john as a member of that group.
1 2 3 4 5 6 7 8 9 10 11 super@R1# show system login group protoadmin { } user john { authentication { encrypted-password ******* } group protoadmin level admin } super@R1#
|
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|
https://math.stackexchange.com/questions/796438/bayesian-statistics-bivariate-prior-distribution
|
# Bayesian statistics, bivariate prior distribution
I've got a simple question buy I'm not sure how to solve it. It's a bit long.
Suppose you've got $n$ iid random variables $X_1$, $\dots$, $X_n$ from the normal distribution with unknown mean $M$ and unknown precision (inverse variance) $H$. Then we've got the likelihood function for data $X_1=x_1$, $\dots$, $X_n=x_n$ $$L_n(\mu,h)\propto h^{n/2}\exp\left(-\frac{1}{2}h\left(n(\bar{x}-\mu)^2+S\right)\right),$$ where $\bar{x}$ is the mean of $x_1$, $\dots$, $x_n$ and $S=\sum_i(x_i-\bar{x})^2$.
Now, a bivariate prior distribution for $(M,H)$ is specified, in terms of hyperparameters $(\alpha_0,\beta_0,m_0,\lambda_0)$, as follows. The marginal distribution of $H$ is $\Gamma(\alpha_0,\beta_0)$ with density $$\pi(h)\propto h^{\alpha_0-1}e^{-\beta_0h}$$ for $h>0$, and the conditional distribution of $M$ given $H=h$ is normal with mean $m_0$ and precision $\lambda_0h$.
Now I should find the posterior joint distribution of $(M,h)$ given data $X_1=x_1$, $\dots$, $X_n=x_n$ and give the updated hyperparameters $(\alpha_n,\beta_n,m_n,\lambda_n)$ in terms of the prior hyperparameters and the data.
Could somebody please tell me how to do this? Thank you very much.
Your prior is just a Normal-gamma distribution. The likelihood is a standard normal likelihood, but obviously taken as the product of the $n$ conditionally independent observations (with the terms in the exponent rewritten by completing the square). The prior is conjugate, so the posterior distribution is also a Normal-gamma distribution. I would advise you to work out & slog through the proportional form & posterior parameters through $$\text{Posterior} \propto \text{Prior} \times \text{Likelihood},$$
|
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|
http://clay6.com/qa/13877/if-the-angle-theta-between-the-vectors-overrightarrow-2x-2-overrightarrow-4
|
Browse Questions
# If the angle $\theta$ between the vectors $\overrightarrow {a}=2x^2 \overrightarrow {i}+ 4x \overrightarrow {j}+ \overrightarrow {k}$ and $\overrightarrow {b}=7 \overrightarrow{i}-2 \overrightarrow {j}+x \overrightarrow {k}$ is such that $90^{\circ} < \theta <180^{\circ}$ then $x$ lies in the interval ::
$\begin {array} {1 1} (1)\;\bigg(0,\frac{1}{2}\bigg) & \quad (2)\;\bigg(\frac{1}{2},1\bigg) \\ (3)\;\bigg(1,\frac{3}{2}\bigg) & \quad (4)\;\bigg(\frac{1}{2},\frac{3}{2}\bigg) \end {array}$
$(1)\;\bigg(0,\frac{1}{2}\bigg)$
|
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|
http://tug.org/pipermail/texhax/2008-June/010652.html
|
# [texhax] Positioning figures in Latex/Beamer
Susana Conde Susana.Conde at ul.ie
Mon Jun 30 11:36:50 CEST 2008
Dear Professor Steven,
I would like to know how to get the distance between the columns
narrower in Beamer (using \begin{columns}, \end{columns}), if that is
possible.
I saw your e-mail address in a page from the help of Beamer (
http://tug.org/mail-archives/texhax/2006-April/005809.html ). In my
example, I have two columns with one graphic in each column (the graphs
are too big for being in one column). Do you know if it is possible to
do this? I have tried to use colsep in this way:
\begin{columns}[colsep=1pt][c]
but it does not work.
I look forward to hearing from you.
Best wishes,
Susana Conde
|
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|
https://www.internal-interfaces.de/2020/09/14/momentum-resolved-charge-transfer-between-two-tmdc-layers-publication-by-b6-hofer-wallauer-and-a13-rohlfing/
|
# Momentum-resolved charge transfer between two TMDC layers – Publication by B6 (Höfer/Wallauer) and A13 (Rohlfing)
### How fast is the charge transfer between two layers of transition metal dichalcogenides (TMDCs) and where does it take place in momentum space? Two-photon photoemission using high-harmonic probe pulses can answer these questions as Wallauer and coworkers demonstrate for the topmost layers of MoS2.
The experiment of Wallauer and coworkers exploits both the high surface sensititivity of photoelectron spectroscopy and the fact, that the bandgap of the topmost layer of TMDCs is enlarged due to reduced screening. By tuning pump pulses below the top-layer gap at K, it is thus possible to excite electrons in deeper layers and probe only the topmost layer. The experiment then images the population dynamics of initially unoccupied electronic states and the charge transfer directly in momentum space with femtosecond time resolution. The results show that the electron transfer between the topmost layers of a 2H-MoS2-crystal, takes place at Σ and proceeds on a timescale of less than 20 fs.
GW-based tight binding calculations by Marauhn and Rohlfing support the experimental findings and explain why the electron transfer takes place at Σ. The GW-based tight-binding calculations not only confirm that the band gap in the surface layer is indeed considerably larger than in deeper layers. They reveal that the coupling between surface and deeper layers is strongly momentum-dependent throughout the Brillouin zone. The coupling is found to be particularly strong at at the conduction-band minimum at Σ, which explains the ultrafast interlayer charge transfer observed in the experiment at this location.
The publication is an “Editor’s Suggestion” in the September 2020 issue of Physical Preview B.
Publication
R. Wallauer, P. Marauhn, J. Reimann, S. Zoerb, F. Kraus, J. Güdde, M. Rohlfing, and U. Höfer
Momentum-resolved observation of ultrafast interlayer charge transfer between the topmost layers of MoS2
Physical Review B 102, 125417 (2020)
Contact
Dr. Robert Wallauer
Philipps-Universität Marburg
SFB 1083 subproject B6
https://internal-interfaces.de/projects/B6
Phone: +49 6421 28-21406
EMAIL
Prof. Dr. Michael Rohlfing
Westfälische Wilhelms-Universität Münster
SFB 1083 subproject A13
https://internal-interfaces.de/projects/A13
Phone: +49 251 83-36340
|
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|
http://mathhelpforum.com/trigonometry/2959-trigonometric-equations-2-a.html
|
# Math Help - Trigonometric equations (2)
1. ## Trigonometric equations (2)
Find the general solution of:
5cot(3x + 4) = 1
2. Originally Posted by LilDragonfly
Find the general solution of:
5cot(3x + 4) = 1
Thus,
$\cot (3x+4)=\frac{1}{5}$
Let,
$y=3x+4$
Then,
$\cot y=\frac{1}{5}$
which you find that,
$y=\cot^{-1}(1/5)+\pi k$
Thus,
$3x+4=\cot^{-1}(1/5)+\pi k$
Thus,
$x=\frac{1}{3}\cot^{-1}(1/5)+\frac{\pi k}{3}-4$
|
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http://cwwm.zite.pw/plotly-cdf.html
|
# Plotly Cdf
Graph data from a MySQL database in Python Published December 8, 2014 January 4, 2016 by modern. Hovering the mouse over the chart type icon, will display three options: 1) Charts like this by Chart Studio users 2) View tutorials on this chart type 3) See a basic example. I know there is density and curve for density functions, but what about plotting distribution functions?. The empirical cumulative distribution function (ECDF) provides an alternative visualisation of distribution. In this post you will discover exactly how you can visualize your machine learning data in Python using Pandas. react-pivottable is part of Plotly's React Component Suite for building data visualization Web apps and products. (To see this, just set u equal to the CDF of the exponential distribution and solve for X). Known Issues None Package List ADGofTest-0. ITL's mission, to cultivate trust in. Datacamp Statistical Thinking ECDF Video-Intro video by Justin Bois where I learned about the existence of ECDFs. They actually combine three plots into one. The input is a list of 5000 values from a Normal distribution with mean 0 and variance 1. r,plot,ggplot2,cdf. 3gp: video/3gpp. My current code below:. November 2017- present. I need to read long file with timestamp in seconds, and plot of CDF using numpy or scipy. plot() to visualize the distribution of a dataset. Hilpisch is the founder and managing partner of The Python Quants, a group focusing on the use of Open Source technologies for Quant Finance and Data Science. Anaconda Documentation ipython. Below you’ll find the code of the ggsurv function. Here are some notes on how to work with probability distributions using the SciPy numerical library for Python. 是以CDF（累计概率密度函数）来表示的。 • 我们内部基于plotly. mosaicsExample. See more ideas about Medicine, Register here and Medical science. No JavaScript required. The dichotomy method (a. js is a high-level, declarative charting library. A cumulative frequency graph or ogive of a quantitative variable is a curve graphically showing the cumulative frequency distribution. There is Plotly. The first being a normal histogram, in which we can state the bin size. We’ll use the lung data set from the survival package for illustration. binom = [source] ¶ A binomial discrete random variable. 6-0 Partial Least Squares and Principal Component Regression. d": false, "binary_prefix": false, "deactivate. Let's take an example of Petrol hike in India. Essentially, when the empirical CDF gives a value close to 0, that's a low value (a small fraction of values are less than or equal to it). A quick and painless way to get 5-number summaries and sample standard deviations. Scatter can be used both for plotting points (makers) or lines, depending on the value of mode. 483\n", "1947-10. A for loop is used for iterating over a sequence (that is either a list, a tuple, a dictionary, a set, or a string). pool <-system. Continuous variables. November 2017- present. There are two common ways to construct a comparative histogram: you can create a panel of histograms, or you can overlay histograms in a single graph. Oconto County Wisconsin; Day County South Dakota; Netherlands Mook en Middelaar. That's where distributions come in. The following are code examples for showing how to use scipy. 45047624 12. 19 Canada | Arroyo Municipality Puerto Rico | Sweden Sotenas | Williamson County Tennessee | Reeves County Texas | Fairfield County Connecticut | Keewatin Canada | Marshall County Alabama | Bryan County Oklahoma | Bayfield County Wisconsin | Lorient France | Roosevelt County New. It displays a list of words, the importance of each beeing shown with font size or color. Ask Question I think the plotly plot is fancy enough to warrant still being included here Evaluate CDF of Student-t. q prefix for the quantile function (i. Interesting parts include using the scipy. Quick Summary Statistics; Normal Distribution Slider. Hilpisch is the founder and managing partner of The Python Quants, a group focusing on the use of Open Source technologies for Quant Finance and Data Science. Purpose: Check If Data Are Approximately Normally Distributed The normal probability plot (Chambers et al. I think the plotly plot is fancy enough to warrant still being included here. In this PoC, a mode attribute is added to histogram traces (and to histogram2d and histogram2dcontour eventually) with two possible values: 'density' (which is wrong, maybe per-bin or raw would be better) and 'cumulative' which would. mimetypeMETA-INF/container. The histogram function uses an automatic binning algorithm that returns bins with a uniform width, chosen to cover the range of elements in X and reveal the underlying shape of the distribution. Violin plots are a hybrid of box plots and kernel density plots. NC State. Quick Introduction to Graphics in R Introduction to the R language CCCB course on R and Bioconductor, May 2012, Aedin Culhane [email protected] An online LaTeX editor that's easy to use. def distribution_plot (self, column, bins = None): """Plot the distribution of a numeric column. We just passed in the values we wanted to evaluate, and the location ($\mu$) and scale($\sigma$) parameters. #' #' Let's see why inverting the CDF using random uniform data works. This is a little more time-consuming than inserting a simple graph, but it you will end up with a great looking box and whiskers graph. November 2017- present. This package provides lots of plotting, various labeling, axis and color scaling functions for R. 3D Vector Plotter. 通联量化实验室是大数据时代的金融量化平台。提供高质量的金融大数据与高效的云计算系统研究，复杂交易策略亦可轻松. Functions related to probability distributions are located in scipy. Ask Question I think the plotly plot is fancy enough to warrant still being included here Evaluate CDF of Student-t. opf application/oebps-package+xml content. So you wouldn't want to send this to plotly anyway! So I cannot exactly reproduce your ggplot example. How can I get this volatility smile with a set of option price? Dichotomy Method. - Plotly, - Matplotlib, - Seaborn - other u sfl p a ck g / ni Py Exploratory Data Analysis Exercise in Python M a c h in e L e a rn in g C o n c e p ts In tro d u c tio n to m a c h in e L e a rn in g S u p e rvis e d a n d U n s u p e rvis e d M L , P a ra m e tric /N o n p a ra m e tric M a c h in e e a rn in g. Matplotlib can be used to create histograms. Index of R packages and their compatability with Renjin. Intern at North Imenti CDF Office April 2016- Aug 2016. Usage dbeta(x, shape1, shape2, ncp=0, log = FALSE) pbeta(q, shape1, shape2, ncp=0, lower. [x,y]=meshgrid(u); % create the grid (the points) on which the functions are evaluated u = normcdf(x,0,1); % compute standard normal cdf values for x v = tcdf(y,3); % compute t3 cdf values for y a = normpdf(x,0,1); % compute standard normal pdf values for x b = tpdf(y,3); % compute t3 pdf values for y f =. Note: Towards the end of the video (maybe minute 13 or so. [x,y]=meshgrid(u); % create the grid (the points) on which the functions are evaluated u = normcdf(x,0,1); % compute standard normal cdf values for x v = tcdf(y,3); % compute t3 cdf values for y a = normpdf(x,0,1); % compute standard normal pdf values for x b = tpdf(y,3); % compute t3 pdf values for y f =. But recently something amazing has happened. How can I get this volatility smile with a set of option price? Dichotomy Method. import numpy as np import scipy. Some things to keep an eye out for when looking at data on a numeric variable: skewness, multimodality. Once a Lens Summary has been generated with lens. The method can be used like this:. How to fit a copula model in R I have been working on this topic for a great amount of time and to be honest I find R documentation not that user-friendly as the documentation for most Python modules. I wrote a python program that basically takes a text file with 86400 lines containing web server ping responses. R has multiple graphics engines. connect-trojan. pool <-system. Usually it has bins, where every bin has a minimum and maximum value. See Details. Intuitively, consider that, if there are $10$ numbers with a uniform distribution, the probability of drawing one of them is $1/10$. I extract the round trip from each line and add it to an array called roundtriptimes. Find the elevation and coordinates of any location on the Topographic Map. Learn how to save a plot to a file using Matplotlib, a plotting library for Python. Analytics helps you measure your users, product, and business. I then sort the array and now want to be able to plot a CDF of the data using matplotlib. In a box plot, numerical data is divided into quartiles, and a box is drawn between the first and third quartiles, with an additional line drawn along the second quartile to mark the median. Unlike other distros, Gentoo Linux has an advanced package management system called Portage. 我们做数据的时候往往会遇到我们想同时展现两组数据，但是两组数据的量级不一样， 那么绘制在一起会导致，数量级小的一组数据的趋势不能明显的看出来， 这个时候往往需要建立一个次坐标轴 接下来我们看一下怎么用plotly进行实现 import plotly. To use a scatter chart, data must be passed as objects containing X and Y properties. Agile Systems Engineering Created framework for linking the why and what with how of aircraft design using visual and virtual product modelling. js is a JavaScript library for manipulating documents based on data. The Ultimate Python Seaborn Tutorial: Gotta Catch ‘Em All Share Google Linkedin Tweet In this step-by-step Seaborn tutorial, you’ll learn how to use one of Python’s most convenient libraries for data visualization. Alternatively, after opening the first graph window, choose History -> Recording from the graph window menu. He kindly let me to publish the problem and the images we were working on, so I decided to explain the problem and write a small guide showing how such a task can be solved. 6-6 Various Plotting Functions pls-2. You can drag the diagram around and zoom in or out by scrolling with the mouse. In the case of GC-MS data, it is more convenient to use to use the metaMS function runCAMERA() than actual CAMERA functions. This format is useful for quickly perceiving the most prominent terms. Further documentation on lattice is planned, in the form of short vignettes describing special use-cases and utilities not covered in the book. pyplot as plt import pandas as pd import numpy as np import plotly. Read file and plot CDF in Python. I know there is density and curve for density functions, but what about plotting distribution functions?. io HoloViews+holoviews. import pandas as pd writer = pd. Strategy running on Amazon EC2 and portfolio value pulled dynamically to plot this using plotly. Ask Question Asked 7 years, 10 months ago. Common subpopulations include males versus females or a control group versus an experimental group. Python plot cdf keyword after analyzing the system lists the list of keywords related and the list of websites with related content, in addition you can see which keywords most interested customers on the this website. @@ -14,21 +14,22 @@ before_script:-chmod +x ci/*. cdf = Cdf(cdf, complement=False, transform=None, **options) Plots a CDF as a line. The following are code examples for showing how to use scipy. r,plot,ggplot2,cdf. d": false, "binary_prefix": false, "deactivate. It shows the distribution of values in a data set across the range of two quantitative variables. SciPy (pronounced "Sigh Pie") is a Python-based ecosystem of open-source software for mathematics, science, and engineering. Cumulative Density Plots with ggplot and plotly. I find this form most useful, but some authors define the CDF in a simpler, less useful way. Select ten random numbers between one and three. The Information Technology Laboratory (ITL), one of six research laboratories within the National Institute of Standards and Technology (NIST), is a globally recognized and trusted source of high-quality, independent, and unbiased research and data. ly/) is a data visualization and analysis platform for making and sharing beautiful, web-based graphs. Learn how to save a plot to a file using Matplotlib, a plotting library for Python. Parameters ---------- column : str Name of the column. To call Shiny code from an R Markdown document, add runtime: shiny to the header, like in this document, which is also available on RStudio Cloud. js by the same author. Add Your Data to Plotly. They actually combine three plots into one. He also shows how to create an ECDF plot using Python. A Graph with Plotly - rstudio-pubs-static. We’ll discuss how to create layouts for dashboards, how to have interactive callbacks, dealing with multiple inputs and outputs, creating interactive components, and more!. CDFs in R (no more histograms) By Chris Leonard Tweet When working with new data, I find it helpful to start by plotting the several variables as I get more familiar with the data. Graphical Primitives Data Visualization with ggplot2 Cheat Sheet RStudio® is a trademark of RStudio, Inc. Seaborn is a Python data visualization library based on matplotlib. to integer values, or heaping, i. They're particularly useful for seeing the full distribution of a dataset. Plotting a Normal Distribution with R I've been tinkering around with R for learning more about the math behind A/B testing and figured I'd share some of the work as I go. 1 An Introduction to R Graphics Chapter preview This chapter provides the most basic information to get started pro-ducing plots in R. ITL’s mission, to cultivate trust in. The fastest way to learn more about your data is to use data visualization. In this tutorial I take a look at distribution plots in Plotly. Visualizing the distribution of a dataset¶ When dealing with a set of data, often the first thing you’ll want to do is get a sense for how the variables are distributed. Sharing concepts, ideas, and codes. png, pdf) (png, hires. import pandas as pd writer = pd. Handling of tied x values. Simulation Programming with Python This chapter shows how simulations of some of the examples in Chap. This package enables the translation of ggplot2 graphs to an interactive web-based version and/or the creation of custom web-based visualizations directly from R. 0,"bold":false,"italic":false,"underline. Moving has kept me pretty busy, but as things are starting to settle down a bit, I've decided to start making an effort to blog regularly (even if it's just a short and simple post like this one). It's free to sign up and bid on jobs. Multipanel plotting in R (with base graphics) Sean Anderson November 22, 2011 Edward Tufte, Envisioning Information: \At the heart of quantitative reasoning is a single question: Compared to. ggplot2 Quick Reference: geom_step. 6-0 Partial Least Squares and Principal Component Regression. Here's a proof-of-concept PR made to attract more attention from our plotly attribute associates @chriddyp @cldougl but also @alexcjohnson @rreusser @monfera. See more ideas about Medicine, Register here and Medical science. Or copy & paste this link into an email or IM:. Special Case - subplot(111). I think the plotly plot is fancy enough to warrant still being included here. Question and answer forum for TIBCO Products. histogram(X) creates a histogram plot of X. R interface to Bokeh. What is a Probability Mass Function? A probability mass function (PMF)— also called a frequency function— gives you probabilities for discrete random variables. Here are some notes on how to work with probability distributions using the SciPy numerical library for Python. Latest sas-graph Jobs* Free sas-graph Alerts Wisdomjobs. Add Your Data to Plotly. If you're doing statistical analysis, you may want to create a standard box plot to show distribution of a set of data. io Find an R package R language docs Run R in your browser R Notebooks R Package Documentation A comprehensive index of R packages and documentation from CRAN, Bioconductor, GitHub and R-Forge. In the data set faithful, a point in the cumulative frequency graph of the eruptions variable shows the total number of eruptions whose durations are less than or equal to a given level. Read file and plot CDF in Python. js' plotmo Plot a Model's Residuals plotrix Various Plotting Functions pls Partial Least Squares and Principal Component Regression plsgenomics PLS Analyses for Genomics plsRglm Partial Least Squares Regression for Generalized Linear Models plyr Tools for Splitting png Read and write PNG images. 通联量化实验室是大数据时代的金融量化平台。提供高质量的金融大数据与高效的云计算系统研究，复杂交易策略亦可轻松. data in Business Intelligence , MySQL , Python All Python code for this tutorial is available online in this IPython notebook. A3, a4Core, abbyyR, abc, abc. Some things to keep an eye out for when looking at data on a numeric variable: skewness, multimodality. 34 Chapter 3. Lab 3: Simulations in R. The optimum interpolation (OI) sea surface temperature (SST) analysis is produced weekly on a one-degree grid. explorer API¶. plot() to visualize the distribution of a dataset. The Beta Distribution Description. gov website, GSA’s Government-wide IT Accessibility Team, and guidance to Federal agencies on accessible information and communication technology (ICT). cat @romain_francois R / C++Romain FRANÇOIS #eRum2016. When you think about sorting your data, you would probably first consider using a function called sort. A 2D density plot or 2D histogram is an extension of the well known histogram. SciPy (pronounced "Sigh Pie") is a Python-based ecosystem of open-source software for mathematics, science, and engineering. Privacy Policy Download and Install R. 52412589 13. ly Bokeh+bokeh. Method #2: Plotting the Cumulative Probabilities Against the Ordered Data. io HoloViews+holoviews. Clicking on the end of a vector will also reveal its individual components. See more examples. fi/display/SpaceWiki/Plasma+physics. Cryptocurrency Arbitrage: Performance - Allen Frostline. Variables and. Advanced knowledge in R programming language and Linux Operative Systems. The initial set of projects to be donated to the CDF are Jenkins, Jenkins X, Spinnaker, and Tekton. In theory, x should go from 0 to positive infinity, but the line gets really close to 0 for values greater than 20. i am very much. edu/introplasma/ Plasma physics Added by Reijo Rasinkangas. The Ultimate Python Seaborn Tutorial: Gotta Catch 'Em All Share Google Linkedin Tweet In this step-by-step Seaborn tutorial, you'll learn how to use one of Python's most convenient libraries for data visualization. It is a React port of the jQuery-based PivotTable. The plot function in R has a type argument that controls the type of plot that gets drawn. io Find an R package R language docs Run R in your browser R Notebooks R Package Documentation A comprehensive index of R packages and documentation from CRAN, Bioconductor, GitHub and R-Forge. dup_axis is provide as a shorthand for creating a secondary axis that is a duplication of the primary axis, effectively mirroring the primary axis. org JupyterandZeppelinNotebooks SoSe2017JörgCassens–Tools 3/57. The page provides the exchange rate of 200 Euro (EUR) to Polish Zloty (PLN), sale and conversion rate. I have few basic questions on R Stem and Leaf Plot [closed] CDF with a massive amount of data. 0-1) BioConductor collection of PCA methods. Learn how to save a plot to a file using Matplotlib, a plotting library for Python. The basis of much of statistical inference and how we get those 95% confidence intervals. a few particular values occur very frequently. Bode Plot Examples. Enter search terms or a module, class or function name. survfit it only requires a fitted survival object to produce a default plot. BioConductor CDF Environment Maker r-bioc-mergeomics (1. Convert z-values into percentiles (and vice versa) by moving the slider. 0, size=None) ¶ Draw random samples from a normal (Gaussian) distribution. cur) for more details. I wrote a python program that basically takes a text file with 86400 lines containing web server ping responses. Add Your Data to Plotly. 通联量化实验室是大数据时代的金融量化平台。提供高质量的金融大数据与高效的云计算系统研究，复杂交易策略亦可轻松. Graph data from a MySQL database in Python Published December 8, 2014 January 4, 2016 by modern. In my continued playing around with ggplot I wanted to create a chart showing the cumulative growth of the number of members of the Neo4j London meetup group. Search for jobs related to Graphs of data or hire on the world's largest freelancing marketplace with 15m+ jobs. Well, it has been a while since I've posted. Histograms Description. To use a scatter chart, data must be passed as objects containing X and Y properties. We just passed in the values we wanted to evaluate, and the location ($\mu$) and scale($\sigma$) parameters. Rcontains function that may be used to graph and visualize the binomial and normal distributions. 2 Customising The Plot Region When plot. 0) Smooth minimum functions for GLSL. The histogram function uses an automatic binning algorithm that returns bins with a uniform width, chosen to cover the range of elements in X and reveal the underlying shape of the distribution. sec_axis is used to create the specifications for a secondary axis. 1-1) GNU R statistical analysis for sparse high-throughput sequencing r-bioc-multtest (2. 1843 sas-graph Active Jobs : Check Out latest sas-graph openings for freshers and experienced. 15 GB of storage, less spam, and mobile access. Also sorts numerical data and uses Plotly. " ], "text/plain": [ " time real_output_per_hour\n", "date \n", "1947-01-01 1947. Built on top of Plotly. h: the y-value(s) for horizontal line(s). 776 Statistical Computing R: Statistical Functions. Plotting in Julia. D3 helps you bring data to life using HTML, SVG, and CSS. Welcome to Statsmodels’s Documentation¶. This R tutorial describes how to create a histogram plot using R software and ggplot2 package. The ecdf function provides one method when the distribution function is not known. @@ -14,21 +14,22 @@ before_script:-chmod +x ci/*. Question and answer forum for TIBCO Products. SciPy library ¶ The SciPy library is one of the core packages that make up the SciPy stack. edu/introplasma/ Plasma physics Added by Reijo Rasinkangas. With a point-and-click interface and tools for batch operations, Origin helps them optimize their daily workflow. The Ultimate Python Seaborn Tutorial: Gotta Catch 'Em All Share Google Linkedin Tweet In this step-by-step Seaborn tutorial, you'll learn how to use one of Python's most convenient libraries for data visualization. plotly as py import IPython from datetime import datetime, timedelta from email. If plot = TRUE, the resulting object of class "histogram" is plotted by plot. He also shows how to create an ECDF plot using Python. 很多时候可能需要在一个图中画出多条函数图像，但是可能y轴的物理含义不一样，或是数值范围相差较大，此时就需要双y轴。 matplotlib和seaborn都可以画双y轴图像。一个例子： import seaborn as sns import matplotlib. Its density function is defined by the following. gaps, outliers. Over 500,000 registered users across corporations, universities and government research labs worldwide, rely on Origin to import, graph, explore, analyze and interpret their data. It is built for making profressional looking, plots quickly with minimal code. January 2018 – Present 1 year 8 months. cdf with CDF Player, or files AVZ_Package. Seaborn is a Python data visualization library with an emphasis on statistical plots. 0-1) BioConductor collection of PCA methods. Check those out. Intuitively, consider that, if there are $10$ numbers with a uniform distribution, the probability of drawing one of them is $1/10$. Open-source JavaScript charting library behind Plotly and Dash - plotly/plotly. ggplot is a plotting system for Python based on R's ggplot2 and the Grammar of Graphics. a few particular values occur very frequently. You can set up Plotly to work in online or offline mode, or in jupyter notebooks. Quick Summary Statistics. 1 Analysis Of Differential Abundance Taking Sample Variation Into Account ASCAT 2. Either a function with a single vector argument returning a single number result or the string "ordered". 3-D plots have been drawn with plotly R package (https://plot. sample and can be carried out analytically or numerically. binom = [source] ¶ A binomial discrete random variable. If you're doing statistical analysis, you may want to create a standard box plot to show distribution of a set of data. RESEARCH AND INNOVATION WORK. By Andrie de Vries, Joris Meys. Adding custom tooltip to plotly using R and ggplot2 syntax Tag: r , ggplot2 , plotly I am trying to create a plotly plot from R using a ggplot object, which has custom labels. If you have introductory to intermediate knowledge in Python and statistics, you can use this article as a one-stop shop for building and plotting. Besides all the listed libraries you can install additional ones in your project. Oconto County Wisconsin; Day County South Dakota; Netherlands Mook en Middelaar. jl is a plotting metapackage which brings many different plotting packages under a single API, making it easy to swap between plotting "backends". Plotting a Normal Distribution with R I've been tinkering around with R for learning more about the math behind A/B testing and figured I'd share some of the work as I go. It provides an interface that is easy to get started with as a beginner, but it also allows you to customize almost every part of a plot. RDF File RDF 22. ly Bokeh+bokeh. Given the distribution parameters they can be used to investigate their statistical properties or to sample non-uniform random numbers. plot(ecdf(endOfMonthPrices), main='CDF of End of Month Price', xlab='Price ($)') Eyeballing the charts, it appears as if the majority of your data suggests the price will wind up between$50 and $150. Scatter Chart. Except for the trans argument any of the arguments can be set to derive() which would result in the secondary axis inheriting the settings from the primary axis. plot(ecdf(endOfMonthPrices), main='CDF of End of Month Price', xlab='Price ($)') Eyeballing the charts, it appears as if the majority of your data suggests the price will wind up between $50 and$150. Saving Plots in R Originally for Statistics 133, by Phil Spector Since R runs on so many different operating systems, and supports so many different graphics formats, it's not surprising that there are a variety of ways of saving your plots, depending on what operating system you are using, what you plan to do with the graph, and whether you're. d": false, "description": null, "dev_url": null, "doc. 3 thoughts on " How to generate bivariate pdfs given a copula and the margins in R and MATLAB " Yuri Salazar Flroes 1. With ShareLaTeX you get the same LaTeX set-up wherever you go. To use a scatter chart, data must be passed as objects containing X and Y properties. If y0 and y1 are the values to the left and right of the point then the value is y0*(1-f)+y1*f so that f=0 is right-continuous and f=1 is left-continuous. Using Pandas and XlsxWriter to create Excel charts An introduction to the creation of Excel files with charts using Pandas and XlsxWriter. jl is a plotting metapackage which brings many different plotting packages under a single API, making it easy to swap between plotting "backends". Cumulative Density Plots with ggplot and plotly. 3D scatterplots and globes. Use a productive notebook interface to weave together narrative text and code to produce elegantly formatted output. For a brief introduction to the ideas behind the library, you can read the introductory notes. Graph data visualization with D3. The empirical cumulative distribution function (ECDF) provides an alternative visualisation of distribution. Grain settling is one of the most important problems in sedimentology (and therefore sedimentary geology), as neither sediment transport nor deposition can be understood and modeled without knowing what is the settling velocity of a particle of a certain grain size. e 10% that. p prefix for the cummulative distribution function (CDF). 3gpp: video/3gpp. def distribution_plot (self, column, bins = None): """Plot the distribution of a numeric column. [x,y]=meshgrid(u); % create the grid (the points) on which the functions are evaluated u = normcdf(x,0,1); % compute standard normal cdf values for x v = tcdf(y,3); % compute t3 cdf values for y a = normpdf(x,0,1); % compute standard normal pdf values for x b = tpdf(y,3); % compute t3 pdf values for y f =. Distribution Plots. > z = seq(-3, 3, by=0. 0, size=None) ¶ Draw random samples from a normal (Gaussian) distribution. Welcome to Statsmodels’s Documentation¶. For a brief introduction to the ideas behind the library, you can read the introductory notes. You may find it helpful to read this other article first: Discrete vs. react-pivottable is a React-based pivot table library with drag'n'drop functionality. survfit it only requires a fitted survival object to produce a default plot. Density, distribution function, quantile function and random generation for the Beta distribution with parameters shape1 and shape2 (and optional non-centrality parameter ncp). Search the history of over 376 billion web pages on the Internet. ggplot2 Quick Reference: geom_step. This method does not use any function specifically created for empirical CDFs; it combines several functions that are more rudimentary in R. ECDF reports for any given number the percent of individuals that are below that threshold. graph_objs as go We'll begin with a basic example of a heatmap. Bokeh visualization library, documentation site. The fact-checkers, whose work is more and more important for those who prefer facts over lies, police the line between fact and falsehood on a day-to-day basis, and do a great job. Today, my small contribution is to pass along a very good overview that reflects on one of Trump’s favorite overarching falsehoods. Namely: Trump describes an America in which everything was going down the tubes under Obama, which is why we needed Trump to make America great again. And he claims that this project has come to fruition, with America setting records for prosperity under his leadership and guidance. “Obama bad; Trump good” is pretty much his analysis in all areas and measurement of U.S. activity, especially economically. Even if this were true, it would reflect poorly on Trump’s character, but it has the added problem of being false, a big lie made up of many small ones. Personally, I don’t assume that all economic measurements directly reflect the leadership of whoever occupies the Oval Office, nor am I smart enough to figure out what causes what in the economy. But the idea that presidents get the credit or the blame for the economy during their tenure is a political fact of life. Trump, in his adorable, immodest mendacity, not only claims credit for everything good that happens in the economy, but tells people, literally and specifically, that they have to vote for him even if they hate him, because without his guidance, their 401(k) accounts “will go down the tubes.” That would be offensive even if it were true, but it is utterly false. The stock market has been on a 10-year run of steady gains that began in 2009, the year Barack Obama was inaugurated. But why would anyone care about that? It’s only an unarguable, stubborn fact. Still, speaking of facts, there are so many measurements and indicators of how the economy is doing, that those not committed to an honest investigation can find evidence for whatever they want to believe. Trump and his most committed followers want to believe that everything was terrible under Barack Obama and great under Trump. That’s baloney. Anyone who believes that believes something false. And a series of charts and graphs published Monday in the Washington Post and explained by Economics Correspondent Heather Long provides the data that tells the tale. The details are complicated. Click through to the link above and you’ll learn much. But the overview is pretty simply this: The U.S. economy had a major meltdown in the last year of the George W. Bush presidency. Again, I’m not smart enough to know how much of this was Bush’s “fault.” But he had been in office for six years when the trouble started. So, if it’s ever reasonable to hold a president accountable for the performance of the economy, the timeline is bad for Bush. GDP growth went negative. Job growth fell sharply and then went negative. Median household income shrank. The Dow Jones Industrial Average dropped by more than 5,000 points! U.S. manufacturing output plunged, as did average home values, as did average hourly wages, as did measures of consumer confidence and most other indicators of economic health. (Backup for that is contained in the Post piece I linked to above.) Barack Obama inherited that mess of falling numbers, which continued during his first year in office, 2009, as he put in place policies designed to turn it around. By 2010, Obama’s second year, pretty much all of the negative numbers had turned positive. By the time Obama was up for reelection in 2012, all of them were headed in the right direction, which is certainly among the reasons voters gave him a second term by a solid (not landslide) margin. Basically, all of those good numbers continued throughout the second Obama term. The U.S. GDP, probably the single best measure of how the economy is doing, grew by 2.9 percent in 2015, which was Obama’s seventh year in office and was the best GDP growth number since before the crash of the late Bush years. GDP growth slowed to 1.6 percent in 2016, which may have been among the indicators that supported Trump’s campaign-year argument that everything was going to hell and only he could fix it. During the first year of Trump, GDP growth grew to 2.4 percent, which is decent but not great and anyway, a reasonable person would acknowledge that — to the degree that economic performance is to the credit or blame of the president — the performance in the first year of a new president is a mixture of the old and new policies. In Trump’s second year, 2018, the GDP grew 2.9 percent, equaling Obama’s best year, and so far in 2019, the growth rate has fallen to 2.1 percent, a mediocre number and a decline for which Trump presumably accepts no responsibility and blames either Nancy Pelosi, Ilhan Omar or, if he can swing it, Barack Obama. I suppose it’s natural for a president to want to take credit for everything good that happens on his (or someday her) watch, but not the blame for anything bad. Trump is more blatant about this than most. If we judge by his bad but remarkably steady approval ratings (today, according to the average maintained by 538.com, it’s 41.9 approval/ 53.7 disapproval) the pretty-good economy is not winning him new supporters, nor is his constant exaggeration of his accomplishments costing him many old ones). I already offered it above, but the full Washington Post workup of these numbers, and commentary/explanation by economics correspondent Heather Long, are here. On a related matter, if you care about what used to be called fiscal conservatism, which is the belief that federal debt and deficit matter, here’s a New York Times analysis, based on Congressional Budget Office data, suggesting that the annual budget deficit (that’s the amount the government borrows every year reflecting that amount by which federal spending exceeds revenues) which fell steadily during the Obama years, from a peak of $1.4 trillion at the beginning of the Obama administration, to$585 billion in 2016 (Obama’s last year in office), will be back up to $960 billion this fiscal year, and back over$1 trillion in 2020. (Here’s the New York Times piece detailing those numbers.) Trump is currently floating various tax cuts for the rich and the poor that will presumably worsen those projections, if passed. As the Times piece reported:
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http://www.uppi.upd.edu.ph/acad/abstracts/2005/parcon
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ABSTRACT OF THE THESIS
### The Social Network of the Filipino Older People
by Cristabel Rose F. Parcon, Master of Arts in Demography (October 2005)
The objectives of this study are to understand the dynamics of the social network of the Filipino older persons in terms of its structure and content, and to determine the influence of the socio-economic and demographic characteristics of the elderly on their network types. The study utilizes the 1996 Philippine Elderly Survey of the University of the Philippines Population Institute (UPPI). Due to data limitation, the social network of the elderly is limited to their spouse, children, parents, siblings and grandchildren.
The network structure is examined by size, composition and geographic dispersion of the network members, while the network content is analyzed by the frequency of interaction between the elderly and their network members and their support intensity. The study focuses on the frequency of the interaction and support exchanges that the quality of these interactions and exchanges are beyond the scope of the study. Two indices of social network, both considering the aspects of network structure and content, were created. These are: (1) Support Relations, defined by the support intensity and composition of the network; and (2) Family Embeddedness, characterized by the geographic dispersion and interaction between the elderly and network members.
Crosstabulations were done in order to determine the differences in the network features and network types by background characteristics of the elderly. Multinomial logistic regression was employed to establish the determinants of the social network of the older people, and then the odds were converted into proportions using the MCA Table. Results show that the young-old, male, high school educated and healthy elderly have better and more favorable network types compared to their respective counterparts. The place of residence of the elderly does not affect their support relations and family embeddedness.
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http://mathoverflow.net/questions/5479/milnors-cartography-problem
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# Milnor's cartography problem
Let $\Omega$ be a round disc of radius $\alpha<\pi/2$ on the standard sphere. It is easy to construct a $(1,\tfrac{\alpha}{\sin\alpha})$-bi-Lipschitz map from $\Omega$ to the plane.
Is it true that any convex domain $\Omega'$ on $S^2$ with the same area as $\Omega$ also admits a $(1,\tfrac{\alpha}{\sin\alpha})$-bi-Lipschitz map to the plane?
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https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica/Electrolysis
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# 1911 Encyclopædia Britannica/Electrolysis
ELECTROLYSIS (formed from Gr. λύειν, to loosen). When the passage of an electric current through a substance is accompanied by definite chemical changes which are independent of the heating effects of the current, the process is known as electrolysis, and the substance is called an electrolyte. As an example we may take the case of a solution of a salt such as copper sulphate in water, through which an electric current is passed between copper plates. We shall then observe the following phenomena. (1) The bulk of the solution is unaltered, except that its temperature may be raised owing to the usual heating effect which is proportional to the square of the strength of the current. (2) The copper plate by which the current is said to enter the solution, i.e. the plate attached to the so-called positive terminal of the battery or other source of current, dissolves away, the copper going into solution as copper sulphate. (3) Copper is deposited on the surface of the other plate, being obtained from the solution. (4) Changes in concentration are produced in the neighbourhood of the two plates or electrodes. In the case we have chosen, the solution becomes stronger near the anode, or electrode at which the current enters, and weaker near the cathode, or electrode at which it leaves the solution. If, instead of using copper electrodes, we take plates of platinum, copper is still deposited on the cathode; but, instead of the anode dissolving, free sulphuric acid appears in the neighbouring solution, and oxygen gas is evolved at the surface of the platinum plate.
With other electrolytes similar phenomena appear, though the primary chemical changes may be masked by secondary actions, Thus, with a dilute solution of sulphuric acid and platinum electrodes, 'Ahydrogen gas is evolved at the cathode, while, as the result of a secondary action on the anode, sulphuric acid is there re-formed, and oxygen gas evolved. Again, with the solution of a salt such as sodium chloride, the sodium, which is primarily liberated at the cathode, decomposes the water and evolves hydrogen, while the chlorine may be evolved as such, may dissolve the anode, or may liberate oxygen from the water, according to the nature of the plate and the concentration of the solution.
Early History of Electrolysis.—Alessandro Volta of Pavia discovered the electric battery in the year 1800, and thus placed the means of maintaining a steady electric current in the hands of investigators, who, before that date, had been restricted to the study of the isolated electric charges given by frictional electric machines. Volta's cell consists essentially of two plates of different metals, such as zinc and copper, connected by an electrolyte such as a solution of salt or acid. Immediately on its discovery intense interest was aroused in the new invention, and the chemical effects of electric currents were speedily detected. W. Nicholson and Sir A. Carlisle found that hydrogen and oxygen were evolved at the surfaces of gold and platinum wires connected with the terminals of a battery and dipped in water. The volume of the hydrogen was about double that of the oxygen, .and, since this is the ratio in which these elements are combined in water, it was concluded that the process consisted essentially in the. decomposition of water. They also noticed that a similar kind of chemical action went on in the battery itself. Soon afterwards, William Cruickshank decomposed the magnesium, sodium and ammonium chlorides, and precipitated silver and copper from their solutions—an observation which led to the process of electroplating. He also found that the liquid round the anode became acid, and that round the cathode alkaline. In 1804 W. Hisinger and J. J. Berzelius stated that neutral salt solutions could be decomposed by electricity, the acid appearing at one pole and the metal at the other. This observation showed that nascent hydrogen was not, as had been supposed, the primary cause of the separation of metals from their solutions, but that the action consisted in a direct decomposition into metal and acid. During the earliest investigation of the subject it was thought that, since hydrogen and oxygen were usually evolved, the electrolysis of solutions of acids and alkalis was to be regarded as a direct decomposition of water. In 1806 Sir Humphry Davy proved that the formation of acid and alkali when water was electrolysed was due to saline impurities in the water. He had shown previously that decomposition of water could be effected although the two poles were placed in separate vessels connected by moistened threads. In 1807 he decomposed potash and soda, previously considered to be elements, by passing the current from a powerful battery through the moistened solids, and thus isolated the metals potassium and sodium.
The electromotive force of Volta's simple cell falls off rapidly when the cell is used, and this phenomenon was shown to be due to the accumulation at the metal plates of the products of chemical changes in the cell itself. This reverse electromotive force of polarization is produced in all electrolytes when the passage of the current changes the nature of the electrodes. In batteries which use acids as the electrolyte, a film of hydrogen tends to be deposited on the copper or platinum electrode; but, to obtain a constant electromotive force, several means were soon devised of preventing the formation of the film. Constant cells may be divided into two groups, according as their action is chemical (as in the bichromate cell, where the hydrogen is converted into water by an oxidizing agent placed in a, porous pot round the carbon plate) or electrochemical (as in Daniell's cell, where a copper plate is surrounded by a solution of copper sulphate, and the hydrogen, instead of being liberated, replaces copper, which is deposited on the plate from the solution).
Fig. 1
Faraday's Laws.—The first exact quantitative study of electrolytic phenomena was made about 1830 by Michael Faraday (Experimental Researches, 1833). When an electric current flows round a circuit, there is no accumulation of electricity anywhere in the circuit, hence the current strength is everywhere the same, and we may picture the current as analogous to the How of an incompressible fluid. Acting on this view, Faraday set himself to examine the relation between the flow of electricity round the circuit and the amount of chemical decomposition. He passed the current driven by a voltaic battery ZnPt (fig. 1) through two branches containing the two electrolytic cells A and B. The reunited current was then led through another cell C, in which the strength of the current must be the sum of those in the arms Aand B. Faraday found that the mass of substance liberated at the electrodes in the cell C was equal to the sum of the masses liberated in the cells A and B. He also found that, for the same current, the amount of chemical action was independent of the size of the electrodes and proportional to the time that the current flowed. Regarding the curre11t as the passage of a certain amount of electricity per second, it will be seen that the results of all these experiments may be summed up in the statement that the amount of chemical action is proportional to the quantity of electricity which passes through the cell.
Faraday's next step was to pass the same current through different electrolytes in series. He found that the amounts of the substances liberated in each cell were proportional to the chemical equivalent weights of those substances. Thus, if the current be passed through dilute sulphuric acid between hydrogen electrodes, and through a solution of copper sulphate, it will be found that the mass of hydrogen evolved in the first cell is to the mass of copper deposited in the second as 1 is to 31.8. Now this ratio is the same as that which gives the relative chemical equivalents of hydrogen and copper, for 1 gramme of hydrogen and 31.8 grammes of copper unite chemically with the same weight of any acid radicle such as chlorine or the sulphuric group, SO4. Faraday examined also the electrolysis of certain fused salts such as lead chloride and silver chloride. Similar relations were found to hold and the amounts of chemical change to be the same for the same electric transfer as in the case of solutions.
We may sum up the chief results of Faraday's work in the statements known as Faraday's laws: The mass of substance liberated from an electrolyte by the passage of a current is proportional (1) to the total quantity of electricity which passes through the electrolyte, and (2) to the chemical equivalent weight of the substance liberated.
Since Faraday's time his laws have been confirmed by modern research, and in favourable cases have been shown to hold good with an accuracy of at least one part in a thousand. The principal object of this more recent research has been the determination of the quantitative amount of chemical change associated with the passage for a given time of a current of strength known in electromagnetic units. It is found that the most accurate and convenient apparatus to use is a platinum bowl filled with a solution of silver nitrate containing about fifteen parts of the salt to one hundred of water. Into the solution dips a silver plate wrapped in filter paper, and the current is passed from the silver plate as anode to the bowl as cathode. The bowl is weighed before and after the passage of the current, and the increase gives the mass of silver deposited. The mean result of the best determinations shows that when a current of one ampere is passed for one second, a mass of silver is deposited equal to 0.001118 gramme. So accurate and convenient is this determination that it is now used conversely as a practical definition of the ampere, which (defined theoretically in terms of magnetic force) is defined practically as the current which in one second deposits 1.118 milligramme of silver.
Taking the chemical equivalent weight of silver, as determined by chemical experiments, to be 107.92, the result described gives as the electrochemical equivalent of an ion of unit chemical equivalent the value 1.036 × 10−5. If, as is now usual, we take the equivalent weight of oxygen as our standard and call it 16, the equivalent weight of hydrogen is 1.008, and its electrochemical equivalent is 1.044 × 105. The electrochemical equivalent of any other substance, whether element or compound, may be found by multiplying its chemical equivalent by 1.036 × 10−5. If, instead of the ampere, we take the C.G.S. electromagnetic unit of current, this number becomes 1.036 × 10−4.
Chemical Nature of the Ions.—A study of the products of decomposition does not necessarily lead directly to a knowledge of the ions actually employed in carrying the current through the electrolyte. Since the electric forces are active throughout the whole solution, all the ions must come under its influence and therefore move, but their separation from the electrodes is determined by the electromotive force needed to liberate them. Thus, as long as every ion of the solution is present in the layer of liquid next the electrode, the one which responds to the least electromotive force will alone be set free. When the amount of this ion in the surface layer becomes too small to carry all the current across the junction, other ions must also be used, and either they or their secondary products will appear also at the electrode. In aqueous solutions, for instance, a few hydrogen (H) and hydroxyl (OH) ions derived from the water are always present, and will be liberated if the other ions require a higher decomposition voltage and the current be kept so small that hydrogen and hydroxyl ions can be formed fast enough to carry all the current across the junction between solution and electrode.
The issue is also obscured in another way. When the ions are set free at the electrodes, they may unite with the substance of the electrode or with some constituent of the solution to form secondary products. Thus the hydroxyl mentioned above decomposes into water and oxygen, and the chlorine produced by the electrolysis of a chloride may attack the metal of the anode. This leads us to examine more closely the part played by water in the electrolysis of aqueous solutions. Distilled water is a very bad conductor, though, even when great care is taken to remove all dissolved bodies, there is evidence to show that some part of the trace of conductivity remaining is due to the water itself. By careful redistillation F. Kohlrausch has prepared water of which the conductivity compared with that of mercury was only 0.40 × 10−11 at 18° C. Even here some little impurity was present, and the conductivity of chemically pure water was estimated by thermodynamic reasoning as 0.36 × 10−11 at 18° C. As we shall see later, the conductivity of very dilute salt solutions is proportional to the concentration, so that it is probable that, in most cases, practically all the current. At the electrodes, however, the small quantity of hydrogen and hydroxyl ions from the water are liberated first in cases where the ions of the salt have a higher decomposition voltage. The water being present in excess, the hydrogen and hydroxyl are re-formed at once and therefore are set free continuously. If the current be so strong that new hydrogen and hydroxyl ions cannot be formed in time, other substances are liberated; in a solution of sulphuric acid a strong current will evolve sulphur dioxide, the more readily as the concentration of the solution is increased. Similar phenomena are seen in the case of a solution of hydrochloric acid. When the solution is weak, hydrogen and oxygen are evolved; but, as the concentration is increased, and the current raised, more and more chlorine is liberated.
An interesting example of secondary action is shown by the common technical process of electroplating with silver from a bath of potassium silver cyanide. Here the ions are potassium and the group Ag(CN)2.[1] Each potassium ion as it reaches the cathode precipitates silver by reacting with the solution in accordance with the chemical equation
K + KAg(CN)2 = 2KCN + Ag,
while the anion Ag(CN)2 dissolves an atom of silver from the anode, and re-forms the complex cyanide KAg(CN)2 by combining with the 2KCN produced in the reaction described in the equation. If the anode consist of platinum, cyanogen gas is evolved thereat from the anion Ag(CN)2, and the platinum becomes covered with the insoluble silver cyanide, AgCN, which soon stops the current. The coating of silver obtained by this process is coherent and homogeneous, while that deposited from a solution of silver nitrate, as the result of the primary action of the current, is crystalline and easily detached.
In the electrolysis of a concentrated solution of sodium acetate, hydrogen is evolved at the cathode and a mixture of ethane and carbon dioxide at the anode. According to H. Jahn,[2] the processes at the anode can be represented by the equations
2CH2 . COO + H2O = 2CH3 . COOH + O
2CH3 . COOH + O = C2H6 + 2CO2 + H2O.
The hydrogen at the cathode is developed by the secondary action
2Na + 2H2O = 2NaOH + H2.
Many organic compounds can be prepared by taking advantage of secondary actions at the electrodes, such as reduction by the cathodic hydrogen, or oxidation at the anode (see Electrochemistry).
It is possible to distinguish between double salts and salts of compound acids. Thus J. W. Hittorf showed that when a current was passed through a solution of sodium platino-chloride, the platinum appeared at the anode. The salt must therefore be derived from an acid, chloroplatinic acid, H2PtCl6, and have the formula Na2PtCl6, the ions being Na and PtCl6″, for if it were a double salt it would decompose as a mixture of sodium chloride and platinum chloride and both metals would go to the cathode.
Early Theories of Electrolysis.—The obvious phenomena to be explained by any theory of electrolysis are the liberation of the products of chemical decomposition at the two electrodes while the intervening liquid is unaltered. To explain these facts, Theodor Grotthus (1785–1822) in 1806 put forward an hypothesis which supposed that the opposite chemical constituents of an electrolyte interchanged partners all along the line between the electrodes when a current passed. Thus, if the molecule of a substance in solution is represented by AB, Grotthus considered a chain of AB molecules to exist from one electrode to the other. Under the influence of an applied electric force, he imagined that the B part of the first molecule was liberated at the anode, and that the A part thus isolated united with the B part of the second molecule, which, in its turn, passed on its A to the B of the third molecule. In this manner, the B part of the last molecule of the chain was seized by the A of the last molecule but one, and the A part of the last molecule liberated at the surface of the cathode.
Chemical phenomena throw further light on this question. If two solutions containing the salts AB and CD be mixed, double decomposition is found to occur, the salts AD and CB being formed till a certain part of the first pair of substances is transformed into an equivalent amount of the second pair. The proportions between the four salts AB, CD, AD and CB, which exist nnally in solution, are found to be the same whether we begin with the pair AB and CD or with the pair AD and CB. To explain this result, chemists suppose that both changes can occur simultaneously, and that equilibrium results when the rate at which AB and CD are transformed into AD and CB is the same as the rate at which the reverse change goes on. A freedom of interchange is thus indicated between the opposite parts of the molecules of salts in solution, and it follows reasonably that with the solution of a single salt, say sodium chloride, continual interchanges go on between the sodium and chlorine parts of the different molecules.
These views were applied to the theory of electrolysis by R. J. E. Clausius. He pointed out that it followed that the electric forces did not cause the interchanges between the opposite parts of the dissolved molecules but only controlled their direction. Interchanges must be supposed to go on whether a current passes or not, the function of the electric forces in electrolysis being merely to determine in what direction the parts of the molecules shall work their way through the liquid and to effect actual separation of these parts (or their secondary products) at the electrodes. This conclusion is supported also by the evidence supplied by the phenomena of electrolytic conduction (see Conduction, Electric, § II.). If we eliminate the reverse electromotive forces of polarization at the two electrodes, the conduction of electricity through electrolytes is found to conform to Ohm's law; that is, once the polarization is overcome, the current is proportional to the electromotive force applied to the bulk of the liquid. Hence there can be no reverse forces of polarization inside the liquid itself, such forces being confined to the surface of the electrodes. No work is done in separating the parts of the molecules from each other. This result again indicates that the parts of the molecules are effectively separate from each other, the function of the electric forces being merely directive.
Fig. 2
Migration of the Ions.—The opposite parts of an electrolyte, which work their way through the liquid under the action of the electric forces, were named by Faraday the ions—the travellers. The changes of concentration which occur in the solution near the two electrodes were referred by W. Hittorf (1853) to the unequal speeds with which he supposed the two opposite ions to travel. It is clear that, when two opposite streams of ions move past each other, equivalent quantities are liberated at the two ends of the system. If the ions move at equal rates, the salt which is decomposed to supply the ions liberated must be taken equally from the neighbourhood of the two electrodes. But if one ion, sav the anion, travels faster through the liquid than the other, the end of the solution from which it comes will be more exhausted of salt than the end towards which it goes. If we assume that no other cause is at work, it is easy to prove that, with non-dis solvable electrodes, the ratio of salt lost at the anode to the salt lost at the cathode must be equal to the ratio of the velocity of the cation to the velocity of the anion. This result may be illustrated by fig. 2. The black circles represent one ion and the white circles the other. If the black ions move twice as fast as the white ones, the state of things after the passage of a current will be represented by the lower part of the figure. Here the middle part of the solution is unaltered and the number of ions liberated is the same at either end, but the amount of salt left at one end is less than that at the other. On the right, towards which the faster ion travels, five molecules of salt are left, being a loss of two from the original seven. On the left, towards which the slower ion moves, only three molecules remain—a loss of four. Thus, the ratio of the losses at the two ends is two to one—the same as the ratio of the assumed ionic velocities. It should be noted, however, that another cause would be competent to explain the unequal dilution of the two solutions. If either ion carried with it some of the unaltered salt or some of the solvent, concentration or dilution of the liquid would be produced where the ion was liberated. There is reason to believe that in certain cases such complex ions do exist., and interfere with the results of the differing ionic velocities.
Hittorf and many other observers have made experiments to determine the unequal dilution of a solution round the two electrodes when a current passes. Various forms of apparatus have been used, the principle of them all being to secure efficient separation of the two volumes of solution in which the changes occur. In some cases porous diaphragms have been employed; but such diaphragms introduce a new complication, for the liquid as a whole is pushed through them by the action of the current, the phenomenon being known as electric endosmose. Hence experiments without separating diaphragms are to be preferred, and the apparatus may be considered effective when a considerable bulk of intervening solution is left unaltered in composition. It is usual to express the results in terms of what is called the migration constant of the anion, that is, the ratio of the amount of salt lost by the anode vessel to the whole amount lost by both vessels. Thus the statement that the migration constant or transport number for a decinormal solution of copper sulphate is 0.632 implies that of every gramme of copper sulphate lost by a solution containing originally one-tenth of a gramme equivalent per litre when a current is passed through it between platinum electrodes, 0.632 gramme is taken from the cathode vessel and 0.368 gramme from the anode vessel. For certain concentrated solutions the transport numberis found to be greater than unity; thus for a normal solution of cadmium iodide its value is 1.12. On the theory that the phenomena are wholly due to unequal ionic velocities this result would mean that the cation like the anion moved against the conventional direction of the current. That a body carrying a positive electric charge should move against the direction of the electric intensity is contrary to all our notions of electric forces, and we are compelled to seek some other explanation. An alternative hypothesis is given by the idea of complex ions. If some of the anions, instead of being simple iodine ions represented chemically by the symbol I, are complex structures formed by the union of iodine With unaltered cadmium iodide—structures represented by some such chemical formula as I(CdI2), the concentration of the solution round the anode would be increased by the passage of an electric current, and the phenomena observed would be explained. It is found that, in such cases as this, where it seems necessary to imagine the existence of complex ions, the transport number changes rapidly as the concentration of the original solution is changed. Thus, diminishing the concentration of the cadmium iodine solution from normal to one-twentieth normal changes the transport number from 1.12 to 0.64. Hence it is probable that in cases where the transport number keeps constant with changing concentration the hypothesis of complex ions is unnecessary, and we may suppose that the transport number is a true migration constant from which the relative velocities of the two ions may be calculated in the matter suggested by Hittorf and illustrated in ng. 2. This conclusion is confirmed by the results of the direct visual determination of ionic velocities (see Conduction, Electric, § II.), which, in cases where the transport number remains constant, agree with the values calculated from those numbers. Many solutions in which the transport numbers vary at high concentration often become simple at greater dilution. For instance, to take the two solutions to which we have already referred, we have—
Concentration 2.0 1.5 1.0 0.5 0.2 0.1 0.05 0.02 0.01 normal Copper sulphate transport numbers 0.72 0.714 0.696 0.668 0.643 0.632 0.626 0.62 .. Cadmium iodide 1.22 1.18 1.12 1.00 0.83 0.71 0.64 0.59 0.56
It is probable that in both these solutions complex ions exist at fairly high concentrations, but gradually gets less in number and finally disappear as the dilution is increased. In such salts as potassium chloride the ions seem to be simple throughout a wide range of concentration since the transport numbers for the same series of concentrations as those used above run—
Potassium chloride—
0.515, 0.515, 0.514, 0.513, 0.509, 0.508, 0.507, 0.506.
The next important step in the theory of the subject was made by F. Kohlrausch in 1879. Kohlrausch formulated a theory of electrolytic conduction based on the idea that, under the action of the electric forces, the oppositely charged ions moved in opposite directions through the liquid, carrying their charges with them. If we eliminate the polarization at the electrodes, it can be shown that an electrolyte possesses a definite electric resistance and therefore a definite conductivity. The conductivity gives us the amount of electricity conveyed per second under a dennite electromotive force. On the view of the process of conduction described above, the amount of electricity conveyed per second is measured by the product of the number of ions, known from the concentration of the solution, the charge carried by each of them, and the velocity with which, on the average, they move through the liquid. The concentration is known, and the conductivity can be measured experimentally; thus the average velocity with which the ions move past each other under the existent electromotive force can be estimated. The velocity with which the ions move past each other is equal to the sum of their individual velocities, which can therefore be calculated. Now Hittorf's transport number, in the case of simple salts in moderately dilute solution, gives us the ratio between the two ionic velocities. Hence the absolute velocities of the two ions can be determined, and we can calculate the actual speed with which a certain ion moves through a given liquid under the action of a given potential gradient or electromotive force. The details of the calculation are given in the article Conduction, Electric, § II., where also will be found an account of the methods which have been used to measure the velocities of many ions by direct visual observation. The results go to show that, where the existence of complex ions is not indicated by varying transport numbers, the observed velocities agree with those calculated on Kohlrausch's theory.
Dissociation Theory.—The verification of Kohlrausch's theory of ionic velocity verifies also the view of electrolysis which regards the electric current as due to streams of ions moving in opposite directions through the liquid and carrying their opposite electric charges with them. There remains the question how the necessary migratory freedom of the ions is secured. As we have seen, Grotthus imagined that it was the electric forces which sheared the ions past each other and loosened the chemical bonds holding the opposite parts of each dissolved molecule together. Clausius extended to electrolysis the chemical ideas which looked on the opposite parts of the molecule as always changing partners independently of any electric force, and regarded the function of the current as merely directive. Still, the necessary freedom was supposed to be secured by interchanges of ions between molecules at the instants of molecular collision only; during the rest of the life of the ions they were regarded as linked to each other to form electrically neutral molecules. In 1887 Svante Arrhenius, professor of physics at Stockholm, put forward a new theory which supposed that the freedom of the opposite ions from each other was not a mere momentary freedom at the instants of molecular collision, but a more or less permanent freedom, the ions moving independently of each other through the liquid. The evidence which led Arrhenius to this conclusion was based on van 't Hoff's work on the osmotic pressure of solutions (see Solution). If a solution, let us say of sugar, be confined in a closed vessel through the walls of which the solvent can pass but the solution cannot, the solvent will enter till a certain equilibrium pressure is reached. This equilibrium pressure is called the osmotic pressure of the solution, and thermodynamic theory shows that, in an ideal case of perfect separation between solvent and solute, it should have the same value as the pressure which a number of molecules equal to the number of solute molecules in the solution would exert if they could exist as agas inaspace equal to the volume of the solution, provided that the space was large enough (i.e. the solution dilute enough) for the intermolecular forces between the dissolved particles to be inappreciable. Van 't Hoff pointed out that measurements of osmotic pressure confirmed this value in the case of dilute solutions of cane sugar.
Thermodynamic theory also indicates a connexion between the osmotic pressure of a solution and the depression of its freezing point and its vapour pressure compared with those of the pure solvent. The freezing points and vapour pressures of solutions of sugar are also in conformity with the theoretical numbers. But when we pass to solutions of mineral salts and acids—to solutions of electrolytes in fact—we find that the observed values of the osmotic pressures and of the allied phenomena are greater than the normal values. Arrhenius pointed out that these exceptions would be brought into line if the ions of electrolytes were imagined to be separate entities each capable of producing its own pressure effects just as would an ordinary dissolved molecule.
Two relations are suggested by Arrhenius' theory. (1) In very dilute solutions of simple substances, where only one kind of dissociation is possible and the dissociation of the ions is complete, the number of pressure-producing particles necessary to produce the observed osmotic effects should be equal to the number of ions given by a molecule of the salt as shown by its electrical properties. Thus the osmotic pressure, or the depression of the freezing point of a solution of potassium chloride should, at extreme dilution, be twice the normal value, but of a solution of sulphuric acid three times that value, since the potassium salt contains two ions and the acid three. (2) As the concentration of the solutions increases, the ionization as measured electrically and the dissociation as measured osmotic ally might decrease more or less together, though, since the thermodynamic theory only holds when the solution is so dilute that the dissolved particles are beyond each other's sphere of action, there is much doubt whether this second relation is valid through any appreciable range of concentration.
At present, measurements of freezing point are more convenient and accurate than those of osmotic pressure, and we may test the validity of Arrhenius' relations by their means. The theoretical value for the depression of the freezing point of a dilute solution per gramme-equivalent of solute per litre is 1.857° C. Completely ionized solutions of salts with two ions should give double this number or 3.714°, while electrolytes with three ions should have a value of 5.57°.
The following results are given by H. B. Loomis for the concentration of 0.01 gramme-molecule of salt to one thousand grammes of water. The salts tabulated are those of which the equivalent conductivity reaches a limiting value indicating that complete ionization is reached as dilution is increased. With such salts alone is a valid comparison possible.
Electrolytes with two Ions. Potassium chloride 3.60 Nitric acid 3.73 Sodium chloride 3.67 Potassium nitrate 3.46 Potassium hydrate 3.71 Sodium nitrate 3.55 Hydrochloric acid 3.61 Ammonium nitrate 3.58 Electrolytes with three Ions. Sulphuric acid 4.49 Calcium chloride 5.04 Sodium sulphate 5.09 Magnesium chloride 5.08
At the concentration used by Loomis the electrical conductivity indicates that the ionization is not complete, particularly in the case of the salts with divalent ions in the second list. Allowing for incomplete ionization the general concordance of these numbers with the theoretical ones is very striking.
The measurements of freezing points of solutions at the extreme dilution necessary to secure complete ionization is a matter of great difficulty, and has been overcome only in a research initiated by E. H. Griffiths.[3] Results have been obtained for solutions of sugar, where the experimental number is 1.858, and for potassium chloride, which gives a depression of 3.720. These numbers agree with those indicated by theory, viz. 1.857 and 3.714, with astonishing exactitude. We may take Arrhenius' first relation as established for the case of potassium chloride.
The second relation, as we have seen, is not a strict consequence of theory, and experiments to examine it must be treated as an investigation of the limits within which solutions are dilute within the thermodynamic sense of the word, rather than as a test of the soundness of the theory. It is found that divergence has begun before the concentration has become great enough to enable freezing points to be measured with any ordinary apparatus. The freezing point curve usually lies below the electrical one, but approaches it as dilution is increased.[4]
Returning once more to the consideration of the first relation, which deals with the comparison between the number of ions and the number of pressure-producing particles in dilute solution, one caution is necessary. In simple substances like potassium chloride it seems evident that one kind of dissociation only is possible. The electrical phenomena show that there are two ions to the molecule, and that these ions are electrically charged. Corresponding with this result we find that the freezing point of dilute solutions indicates that two pressure-producing particles per molecule are present. But the converse relation does not necessarily follow. It would be possible for a body in solution to be dissociated into non-electrical parts, which would give osmotic pressure effects twice or three times the normal value, but, being uncharged, would not act as ions and impart electrical conductivity to the solution. L. Kahlenberg (Jour. Phys. Chem., 1901, v. 344, 1902, vi. 43) has found that solutions of diphenylamine in methyl cyanide possess an excess of pressure-producing particles and yet are non-conductors of electricity. It is possible that in complicated organic substances we might have two kinds of dissociation, electrical and non-electrical, occurring simultaneously, while the possibility of the association of molecules accompanied by the electrical dissociation of some of them into new parts should not be overlooked. It should be pointed out that no measurements on osmotic pressures or freezing points can do more than tell us that an excess of particles is present; such experiments can throw no light on the question whether or not those particles are electrically charged. That question can only be answered by examining whether or not the particles move in an electric field.
The dissociation theory was originally suggested by the osmotic pressure relations. But not only has it explained satisfactorily the electrical, properties of solutions, but it seems to be the only known hypothesis which is consistent with the experimental relation between the concentration of a solution and its electrical conductivity (see Conduction, Electric, § II., "Nature of Electrolytes"). It is probable that the electrical effects constitute the strongest arguments in favour of the theory. It is necessary to point out that the dissociated ions of such a body as potassium chloride are not in the same condition as potassium and chlorine in the free state. The ions are associated with very large electric charges, and, whatever their exact relations with those charges may be, it is certain that the energy of a system in such a state must be different from its energy when unelectrified. It is not unlikely, therefore, that even a compound as stable in the solid form as potassium chloride should be thus dissociated when dissolved. Again, water, the best electrolytic solvent known, is also the body of the highest specific inductive capacity (dielectric constant), and this property, to whatever cause it may be due, will reduce the forces between electric charges in the neighbourhood, and may therefore enable two ions to separate.
This view of the nature of electrolytic solutions at once explains many well-known phenomena. Other physical properties of these solutions, such as density, colour, optical rotatory power, &c., like the conductivities, are additive, i.e. can be calculated by adding together the corresponding properties of the parts. This again suggests that these parts are independent of each other. For instance, the colour of a salt solution is the colour obtained by the superposition of the colours of the ions and the colour of any undissociated salt that may be present. All copper salts in dilute solution are blue, which is therefore the colour of the copper ion. Solid copper chloride is brown or yellow, so that its concentrated solution, which contains both ions and undissociated molecules, is green, but changes to blue as water is added and the ionization becomes complete. A series of equivalent solutions all containing the same coloured ion have absorption spectra which, when photographed, show identical absorption bands of equal intensity.[5] The colour changes shown by many substances which are used as indicators (q.v.) of acids or alkalis can be explained in a similar way. Thus para-nitrophenol has colourless molecules, but an intensely yellow negative ion. In neutral, and still more in acid solutions, the dissociation of the indicator is practically nothing, and the liquid is colourless. If an alkali is added, however, a highly dissociated salt of para-nitrophenol is formed, and the yellow colour is at once evident. In other cases, such as that of litmus, both the ion and the undissociated molecule are coloured, but in different ways.
Electrolytes possess the power of coagulating solutions of colloids such as albumen and arsenious sulphide. The mean values of the relative coagulative powers of sulphates of monodi- and tri-valent metals have been shown experimentally to be approximately in the ratios 1:35:1023. The dissociation theory refers this to the action of electric charges carried by the free ions. If a certain minimum charge must be collected in order to start coagulation, it will need the conjunction of 6n monovalent, or 3n divalent, to equal the effect of 2n trivalent ions. The ratios of the coagulative powers can thus be calculated to be 1:x:x2, and putting x = 32 we get 1:32:1024, a satisfactory agreement with the numbers observed.[6]
The question of the application of the dissociation theory to the case of fused salts remains. While it seems clear that the conduction in this case is carried on by ions similar to those of solutions, since Faraday's laws apply equally to both, it does not follow necessarily that semi-permanent dissociation is the only way to explain the phenomena. The evidence in favour of dissociation in the case of solutions does not apply to fused salts, and it is possible that, in their case, a series of molecular interchanges, somewhat like Grotthus's chain, may represent the mechanism of conduction.
An interesting relation appears when the electrolytic conductivity of solutions is compared with their chemical activity. The readiness and speed with which electrolytes react are in sharp contrast with the difficulty experienced in the case of non-electrolytes. Moreover, a study of the chemical relations of electrolytes indicates that it is always the electrolytic ions that are concerned in their reactions. The tests for a salt, potassium nitrate, for example, are the tests not for KNO3, but for its ions K and NO3, and in cases of double decomposition it is always these ions that are exchanged for those of other substances. If an element be present in a compound otherwise than as an ion, it is not interchangeable, and cannot be recognized by the usual tests. Thus neither a chlorate, which contains the ion ClO3, nor monochloracetic acid, shows the reactions of chlorine, though it is, of course, present in both substances; again, the sulphates do not answer to the usual tests which indicate the presence of sulphur as sulphide. The chemical activity of a substance is a quantity which may be measured by different methods. For some substances it has been shown to be independent of the particular reaction used. It is then possible to assign to each body a specific coefficient of affinity. Arrhenius has pointed out that the coefficient of affinity of an acid is proportional to its electrolytic ionization.
The affinities of acids have been compared in several ways. W. Ostwald (Lehrbuch der allg. Chemie, vol. ii., Leipzig, 1893) investigated the relative affinities of acids for potash, soda and ammonia, and proved them to be independent of the base used. The method employed was to measure the changes in volume caused by the action. His results are given in column I. of the following table, the affinity of hydrochloric acid being taken as one hundred. Another method is to allow an acid to act on an insoluble salt, and to measure the quantity which goes into solution. Determinations have been made with calcium oxalate, CaC2O4 + H2O, which is easily decomposed by acids, oxalic acid and a soluble calcium salt being formed. The affinities of acids relative to that of oxalic acid are thus found, so that the acids can be compared among themselves (column II.). If an aqueous solution of methyl acetate be allowed to stand, a slow decomposition goes on. This is much quickened by the presence of a little dilute acid, though the acid itself remains unchanged. It is found that the influence of different acids on this action is proportional to their specific coefficients of affinity. The results of this method are given in column III. Finally, in column IV. the electrical conductivities of normal solutions of the acids have been tabulated. A better basis of comparison would be the ratio of the actual to the limiting conductivity, but since the conductivity of acids is chiefly due to the mobility of the hydrogen ions, its limiting value is nearly the same for all, and the general result of the comparison would be unchanged.
Acid. I. II. III. IV. Hydrochloric 100 100 100 100 Nitric 102 110 92 99.5 Sulphuric 68 67 74 65.1 Formic 4.0 2.5 1.3 1.7 Acetic 1.2 1.0 0.3 0.4 Propionic 1.1 .. 0.3 0.3 Monochloracetic 7.2 5.1 4.3 4.9 Dichloraeetic 34 18 23.0 25.3 Trichloracetic 82 63 68.2 62.3 Malic 3.0 5.0 1.2 1.3 Tartaric 5.3 6.3 2.3 2.3 Succinic 0.1 0.2 0.5 0.6
It must be remembered that, the solutions not being of quite the same strength, these numbers are not strictly comparable, and that the experimental difficulties involved in the chemical measurements are considerable. Nevertheless, the remarkable general agreement of the numbers in the four columns is quite enough to show the intimate connexion between chemical activity and electrical conductivity. We may take it, then, that only that portion of these bodies is chemically active which is electrolytically active—that ionization is necessary for such chemical activity as we are dealing with here, just as it is necessary for electrolytic conductivity.
The ordinary laws of chemical equilibrium have been applied to the case of the dissociation of a substance into its ions. Let ${\displaystyle x}$ be the number of molecules which dissociate per second when the number of undissociated molecules in unit volume is unity, then in a dilute solution where the molecules do not interfere with each other, ${\displaystyle xp}$ is the number when the concentration is ${\displaystyle p.}$ Recombination can only occur when two ions meet. and since the frequency with which this will happen is, in dilute solution, proportional to the square of the ionic concentration, we shall get for the number of molecules re-formed in one second ${\displaystyle yq^{2}}$ where ${\displaystyle q}$ is the number of dissociated molecules in one cubic centimetre; When there is equilibrium, ${\displaystyle xp{=}yq^{2}.}$ If ${\displaystyle \mu }$ be the molecular conductivity, and ${\displaystyle \mu _{\infty }}$ its value at infinite dilution, the fractional number of molecules dissociated is ${\displaystyle \mu /\mu _{\infty },}$ which we may write as ${\displaystyle \alpha }$ The number of undissociated molecules is then ${\displaystyle 1-\alpha ,}$ so that if ${\displaystyle {\text{V}}}$ be the volume of the solution containing 1 gramme-molecule of the dissolved substance, we get
${\displaystyle q{=}\alpha /{\text{V}}}$and${\displaystyle p{=}(1-\alpha )/{\text{V}},}$
hence${\displaystyle x(1-\alpha ){\text{ V}}{=}ya^{2}/{\text{V}}^{2},}$
and${\displaystyle {\frac {\alpha ^{2}}{{\text{V}}(1-\alpha )}}{=}{\frac {x}{y}}{=}{\text{constant}}{=}k.}$
This constant ${\displaystyle k}$ gives a numerical value for the chemical affinity, and the equation should represent the effect of dilution on the molecular conductivity of binary electrolytes.
In the case of substances like ammonia and acetic acid, where the dissociation is very small, ${\displaystyle 1-a}$ is nearly equal to unity, and only varies slowly with dilution. The equation then becomes ${\displaystyle a^{2}/{\text{V}}{=}k,}$ or ${\displaystyle \alpha {=}{\sqrt {{\text{V}}k}}}$ so that the molecular conductivity is proportional to the square root of the dilution. Ostwald has confirmed the equation by observation on an enormous number of weak acids (Zeits. pkysikal. Chemie, 1888, ii. p. 278; 1889, iii. pp. 170, 241, 369). Thus in the case of cyanacetic acid, while the volume ${\displaystyle {\text{V}}}$ changed by doubling from 16 to 1024 litres, the values of ${\displaystyle k}$ were 0.00 (376, 373, 374, 361, 362, 361, 368). The mean values of ${\displaystyle k}$ for other common acids were-formic, 0.0000214; acetic, 0.0000180; monochloracetic, 0.00155; dichloracetic, 0.051; trichloracetic, 1.21; propionic, 0.0000134. From these numbers we can, by help of the equation, calculate the conductivity of the acids for any dilution. The value of ${\displaystyle k,}$ however, does not keep constant so satisfactorily in the case of highly dissociated substances, and empirical formulae have been constructed to represent the effect of dilution on them. Thus the values of the expressions ${\displaystyle \alpha ^{2}/(1-\alpha {\sqrt {\text{V}}})}$ (Rudolphi, Zeits. physikal. Chemie, 1895, vol. xvii. p. 385) and ${\displaystyle \alpha ^{3}(1-\alpha )^{2}{\text{V}}}$ (van 't Hoff, ibid., 1895, vol. xviii. p. 300) are found to keep constant as ${\displaystyle {\text{V}}}$ changes. Van 't Hoff's formula is equivalent to taking the frequency of dissociation as proportional to the square of the concentration of the molecules, and the frequency of recombination as proportional to the cube of the concentration of the ions. An explanation of the failure of the usual dilution law in these cases may be given if we remember that, while the electric forces between bodies like undissociated molecules, each associated with equal and opposite charges, will vary inversely as the fourth power of the distance, the forces between dissociated ions, each carrying one charge only, will be inversely proportional to the square of the distance. The forces between the ions of a strongly dissociated solution will thus be considerable at a dilution which makes forces between undissociated molecules quite insensible, and at the concentrations necessary to test Ostwald's formula an electrolyte will be far from dilute in the thermodynamic sense of the term, which implies no appreciable intermolecular or inter ionic forces.
When the solutions of two substances are mixed, similar considerations to those given above enable us to calculate the resultant changes in dissociation. (See Arrhenius, loc. cit.) The simplest and most important case is that of two electrolytes having one ion in common, such as two acids. It is evident that the undissociated part of each acid must eventually be in equilibrium with the free hydrogen ions, and, if the concentrations are not such as to secure this condition, readjustment must occur. In order that there should be no change in the states of dissociation on mixing, it is necessary, therefore, that the concentration of the hydrogen ions should be the same in each separate solution. Such solutions were called by Arrhenius “isohydric.” The two solutions, then, will so act on each other when mixed that they become isohydric. Let us suppose that we have one very active acid like hydrochloric, in which dissociation is nearly complete, another like acetic, in which it is very small. In order that the solutions of these should be isohydric and the concentrations of the hydrogen ions the same, we must have a very large quantity of the feebly dissociated acetic acid, and a very small quantity of the strongly dissociated hydrochloric, and in such proportions alone will equilibrium be possible. This explains the action of a strong acid on the salt of a weak acid. Let us allow dilute sodium acetate to react with dilute hydrochloric acid. Some acetic acid is formed, and this process will go on till the solutions of the two acids are isohydric: that is, till the dissociated hydrogen ions are in equilibrium with both. In order that this should hold, we have seen that a considerable quantity of acetic acid must be present, so that a corresponding amount of the salt will be decomposed, the quantity being greater the less the acid is dissociated. This “replacement” of a “weak” acid by a “strong” one is a matter of common observation in the chemical laboratory. Similar investigations applied to the general case of chemical equilibrium lead to an expression of exactly the same form as that given by C. M. Guldberg and P. Waage, which is universally accepted as an accurate representation of the facts.
The temperature coefficient of conductivity has approximately the same value for most aqueous salt solutions. It decreases both as the temperature is raised and as the concentration is increased, ranging from about 3.5% per degree for extremely dilute solutions (i.e. practically pure water) at 0° to about 1.5 for concentrated solutions at 18°. For acids its value is usually rather less than for salts at equivalent concentrations. The influence of temperature on the conductivity of solutions depends on (1) the ionization, and (2) the frictional resistance of the liquid to the passage of the ions, the reciprocal of which is called the ionic fluidity. At extreme dilution, when the ionization is complete, a variation in temperature cannot change its amount. The rise of conductivity with temperature, therefore, shows that the fluidity becomes greater when the solution is heated. As the concentration is increased and un-ionized molecules are formed, a change in temperature begins to affect the ionization as well as the fluidity. But the temperature coefficient of conductivity is now generally less than before; thus the effect of temperature on ionization must be of opposite sign to its effect on fluidity. The ionization of a solution, then, is usually diminished by raising the temperature, the rise in conductivity being due to the greater increase in fluidity. Nevertheless, in certain cases, the temperature coefficient of conductivity becomes negative at high temperatures, a solution of phosphoric acid, for example, reaching maximum conductivity at 75° C.
The dissociation theory gives an immediate explanation of the fact that, in general, no heat-change occurs when two neutral salt solutions are mixed. Since the salts, both before and after mixture, exist mainly as dissociated ions, it is obvious that large thermal effects can only appear when the state of dissociation of the products is very different from that of the reagents. Let us consider the case of the neutralization of a base by an acid in the light of the dissociation theory. In dilute solution such substances as hydrochloric acid and potash are almost completely dissociated, so that, instead of representing the reaction as
HCl + KOH = KCl + H2O,
we must write
+ – + – + – H + Cl + K + OH = K + Ck + H2O
The ions K and Cl suffer no change, but the hydrogen of the acid and the hydroxyl (OH) of the potash unite to form water, which is only very slightly dissociated. The heat liberated, then, is almost exclusively that produced by the formation of water from its ions. An exactly similar process occurs when any strongly dissociated acid acts on any strongly dissociated base, so that in all such cases the heat evolution should be approximately the same. This is fully borne out by the experiments of Julius Thomsen, who found that the heat of neutralization of one gramme-molecule of a strong base by an equivalent quantity of a strong acid was nearly constant, and equal to 13,700 or 13,800 calories. In the case of weaker acids, the dissociation of which is less complete, divergences from this constant value will occur, for some of the molecules have to be separated into their ions. For instance, sulphuric acid, which in the fairly strong solutions used by Thomsen is only about half dissociated, gives a higher value for the heat of neutralization, so that heat must be evolved when it is ionized. The heat of formation of a substance from its ions is, of course, very different from that evolved when it is formed from its elements in the usual way, since the energy associated with an ion is different from that possessed by the atoms of the element in their normal state. We can calculate the heat of formation from its ions for any substance dissolved in a given liquid, from a knowledge of the temperature coefficient of ionization, by means of an application of the well-known thermodynamical process, which also gives the latent heat of evaporation of a liquid when the temperature coefficient of its vapour pressure is known. The heats of formation thus obtained may be either positive or negative, and by using them to supplement the heat of formation of water, Arrhenius calculated the total heats of neutralization of soda by different acids, some of them only slightly dissociated, and found values agreeing well with observation (Zeits. physikal. Chemie, 1889, 4, p. 96; and 1892, 9, p. 339)
Voltaic Cells.—When two metallic conductors are placed in an electrolyte, a current will flow through a wire connecting them provided that a difference of any kind exists between the two conductors in the nature either of the metals or of the portions of the electrolyte which surround them. A current can be obtained by the combination of two metals in the same electrolyte, of two metals in different electrolytes, of the same metal in different electrolytes, or of the same metal in solutions of the same electrolyte at different concentrations. In accordance with the principles of energetics (q.v.), any change which involves a decrease in the total available energy of the system will tend to occur, and thus the necessary and sufficient condition for the production of electromotive force is that the available energy of the system should decrease when the current flows.
In order that the current should be maintained, and the electromotive force of the cell remain constant during action, it is necessary to ensure that the changes in the cell, chemical or other, which produce the current, should neither destroy the difference between the electrodes, nor coat either electrode with a non-conducting layer through which the current cannot pass. As an example of a fairly constant cell we may take that of Daniell, which consists of the electrical arrangement—zinc | zinc sulphate solution | copper sulphate solution | copper,—the two solutions being usually separated by a pot of porous earthenware. When the zinc and copper plates are connected through a wire, a current flows, the conventionally positive electricity passing from copper to zinc in the wire and from zinc to copper in the cell. Zinc dissolves at the anode, an equal amount of zinc replaces an equivalent amount of copper on the other side of the porous partition, and the same amount of copper is deposited on the cathode. This process involves a decrease in the available energy of the system, for the dissolution of zinc gives out more energy than the separation of copper absorbs. But the internal rearrangements which accompany the production of a current do not cause any change in the original nature of the electrodes, fresh zinc being exposed at the anode, and copper being deposited on copper at the cathode. Thus as long as a moderate current flows, the only variation in the cell is the appearance of zinc sulphate in the liquid on the copper side of the porous wall. In spite of this appearance, however, while the supply of copper is maintained, copper, being more easily separated from the *solution than zinc, is deposited alone at the cathode, and the cell remains constant.
It is necessary to observe that the condition for change in a system is that the total available energy of the whole system should be decreased by the change. We must consider what change is allowed by the mechanism of the system, and deal with the sum of all the alterations in energy. Thus in the Daniell cell the dissolution of copper as well as of zinc would increase the loss in available energy. But when zinc dissolves, the zinc ions carry their electric charges with them, and the liquid tends to become positively electrified. The electric forces then soon stop further action unless an equivalent quantity of positive ions are removed from the solution. Hence zinc can only dissolve when some more easily separable substance is present in solution to be removed pari passu with the dissolution of zinc. The mechanism of such systems is well illustrated by an experiment devised by W. Ostwald. Plates of platinum and pure or amalgamated zinc are separated by a porous pot, and each surrounded by some of the same solution of a salt of a metal more oxidizable than zinc, such as potassium. When the plates are connected together by means of a wire, no current flows, and no appreciable amount of zinc dissolves, for the dissolution of zinc would involve the separation of potassium and a gain in available energy. If sulphuric acid be added to the vessel containing the zinc, these conditions are unaltered and still no zinc is dissolved. But, on the other hand, if a few drops of acid be placed in the vessel with the platinum, bubbles of hydrogen appear, and a current flows, zinc dissolving at the anode, and hydrogen being liberated at the cathode. In order that positively electrified ions may enter a solution, an equivalent amount of other positive ions must be removed or negative ions be added, and, for the process to occur spontaneously, the possible action at the two electrodes must involve a decrease in the total available energy of the system.
Considered thermodynamically, voltaic cells must be divided into reversible and non-reversible systems. If the slow processes of diffusion be ignored, the Daniell cell already described may be taken as a type of a reversible cell. Let an electromotive force exactly equal to that of the cell be applied to it in the reverse direction. When the applied electromotive force is diminished by an inhnitesimal amount, the cell produces a current in the usual direction, and the ordinary chemical changes occur. If the external electromotive force exceed that of the cell by ever so little, a current flows in the opposite direction, and all the former chemical changes are reversed, copper dissolving from the copper plate, while zinc is deposited on the zinc plate. The cell, together with this balancing electromotive force, is thus a reversible system in true equilibrium, and the thermodynamical reasoning applicable to such systems can be used to examine its properties.
Now a well-known relation connects the available energy of a reversible system with the corresponding change in its total internal energy.
The available energy ${\displaystyle {\text{A}}}$ is the amount of external work obtainable by an infinitesimal, reversible change in the system which occurs at a constant temperature ${\displaystyle {\text{T.}}}$ If ${\displaystyle {\text{I}}}$ be the change in the internal energy, the relation referred to gives us the equation
${\displaystyle {\text{A}}{=}{\text{I}}+{\text{T}}(d{\text{A}}/d{\text{T}}),}$
where ${\displaystyle d{\text{A}}/d{\text{T}}}$ denotes the rate of change of the available energy of the system per degree change in temperature. During a small electric transfer through the cell, the external work done is ${\displaystyle {\text{E}}e}$ where ${\displaystyle {\text{E}}}$ is the electromotive force. If the chemical changes which occur in the cell were allowed to take place in a closed vessel without the performance of electrical or other work, the change in energy would be measured by the heat evolved. Since the fina state of the system would be the same as in the actual processes of the cell, the same amount of heat must give a measure of the change in internal energy when the cell is in action. Thus, if ${\displaystyle {\text{L}}}$ denote the heat corresponding with the chemical changes associated with unit electric transfer, ${\displaystyle {\text{L}}e}$ will be the heat corresponding with an electric transfer ${\displaystyle e,}$ and will also be equal to the change in internal energy of the cell. Hence we get the equation
${\displaystyle {\text{E}}e{=}{\text{L}}e+{\text{T}}e(d{\text{E}}/d{\text{T}})}$or${\displaystyle {\text{E}}{=}{\text{L}}+{\text{T}}(d{\text{E}}/d{\text{T}}),}$
as a particular case of the general thermodynamic equation of available energy. This equation was obtained in different ways by J. Willard Gibbs and H. von Helmholtz.
It will be noticed that when ${\displaystyle d{\text{E}}/d{\text{T}}}$ is zero, that is, when the electromotive force of the cell does not change with temperature, the electromotive force is measured by the heat of reaction per unit of electrochemical change. The earliest formulation of the subject, due to Lord Kelvin, assumed that this relation was true in all cases, and, calculated in this way, the electromotive force of Daniell's cell, which happens to possess a very small temperature coefficient, was found to agree with observation.
When one gramme of zinc is dissolved in dilute sulphuric acid, 1670 thermal units or calories are evolved. Hence for the electrochemical unit of zinc or 0.003388 gramme, the thermal evolution is 5.66 calories. Similarly, the heat which accompanies the dissolution of one electrochemical unit of copper is 3.00 calories. Thus, the thermal equivalent of the unit of resultant electrochemical change in Daniell's cell is 5.66 – 3.00 = 2.66 calories. The dynamical equivalent of the calorie is 4.18 X 107 ergs or C.G.S. units of work, and therefore the electromotive force of the cell should be 1.112 X 108 C.G.S. units or 1.112 volts—a close agreement with the experimental result of about 1.08 volts. For cells in which the electromotive force varies with temperature, the full equation given by Gibbs and Helmholtz has also been confirmed experimentally.
As stated above, an electromotive force is set up whenever there is a difference of any kind at two electrodes immersed in electrolytes. In ordinary cells the difference is secured by using two dissimilar metals, but an electromotive force exists if two plates of the same metal are placed in solutions of different substances, or of the same substance at different concentrations. In the latter case, the tendency of the metal to dissolve in the more dilute solution is greater than its tendency to dissolve in the more concentrated solution, and thus there is a decrease in available energy when metal dissolves in the dilute solution and separates in equivalent quantity from the concentrated solution. An electromotive force is therefore set up in this direction, and, if we can calculate the change in available energy due to the processes of the cell, we can foretell the value of the electromotive force. Now the effective change produced by the action of the current is the concentration of the more dilute solution by the dissolution of metal in it, and the dilution of the originally stronger solution by the separation of metal from it. We may imagine these changes reversed in two ways. We may evaporate some of the solvent from the solution which has become weaker and thus re concentrate it, condensing the vapour on the solution which had become stronger. By this reasoning Helmholtz showed how to obtain an expression for the work done. On the other hand, we may imagine the processes due to the electrical transfer to be reversed by an osmotic operation. Solvent may be supposed to be squeezed out from the solution which has become more dilute through a semi-permeable wall, and through another such wall allowed to mix with the solution which in the electrical operation had become more concentrated. Again, we may calculate the osmotic work done, and, if the whole cycle of operations be supposed to occur at the same temperature, the osmotic work must be equal and opposite to the electrical work of the first operation.
The result of the investigation shows that the electrical work ${\displaystyle {\text{E}}e}$ is given by then equation
${\displaystyle {\text{E}}e{=}\int _{p1}^{p2}vdp,}$
where ${\displaystyle v}$ is the volume of the solution used and ${\displaystyle p}$ its osmotic pressure. When the solutions may be taken as effectively dilute, so that the gas laws apply to the osmotic pressure, this relation reduces to
${\displaystyle {\text{E}}{=}{\frac {nr{\text{RT}}}{ey}}\log _{e}{\frac {c_{1}}{c_{2}}}}$
where ${\displaystyle n}$ is the number of ions given by one molecule of the salt, ${\displaystyle r}$ the transport ratio of the anion, ${\displaystyle {\text{R}}}$ the gas constant, ${\displaystyle {\text{T}}}$ the absolute temperature, ${\displaystyle y}$ the total valency of the anions obtained from one molecule, and ${\displaystyle c_{1}}$ and ${\displaystyle c_{2}}$ the concentrations of the two solutions.
If we take as an example a concentration cell in which silver plates are placed in solutions of silver nitrate, one of which is ten times as strong as the other, this equation gives
{\displaystyle {\begin{aligned}{\text{E}}&{=}0.060\times 10^{3}{\text{ C.G.S. units}}\\&{=}0.060{\text{ volts}}\end{aligned}}}
Nernst, to whom this theory is due, determined the electromotive force of this cell experimentally, and found the value 0.055 volt.
The logarithmic formulae for these concentration cells indicate that theoretically their electromotive force can be increased to any extent by diminishing without limit the concentration of the more dilute solution, ${\displaystyle \log c_{1}/c_{2}}$ then becoming very great. This condition may be realized to some extent in a manner that throws light on the general theory of the voltaic cell. Let us consider the arrangement-silver | silver chloride with potassium chloride solution | potassium nitrate solution | silver nitrate solution | silver. Silver chloride is a very insoluble substance, and here the amount in solution is still further reduced by the presence of excess of chlorine ions of the potassium salt. Thus silver, at one end of the cell in contact with many silver ions of the silver nitrate solution, at the other end is in contact with a liquid in which the concentration of those ions is very small indeed. The result is that a high electromotive force is set up, which has been calculated as 0.52 volt, and observed as 0.51 volt. Again, Hittorf has shown that the effect of a cyanide round a copper electrode is to combine with the copper ions. The concentration of the simple copper ions is then so much diminished that the copper plate becomes an anode with regard to zinc. Thus the cell-copper | potassium cyanide solution | potassium sulphate solution-zinc sulphate solution | zinc-gives a current which carries copper into solution and deposits zinc. In a similar way silver could be made to act as anode with respect to cadmium.
It is now evident that the electromotive force of an ordinary chemical cell such as that of Daniell depends on the concentration of the solutions as well as on the nature of the metals. In ordinary cases possible changes in the concentrations only affect the electromotive force by a few parts in a hundred, but, by means such as those indicated above, it is possible to produce such immense differences in the concentrations that the electromotive force of the cell is not only changed appreciably but even reversed in direction. Once more we see that it is the total impending change in the available energy of the system which controls the electromotive force.
Any reversible cell can theoretically be employed as an accumulator, though, in practice, conditions of general convenience are more sought after than thermodynamic efficiency. The effective electromotive force of the common lead accumulator (q.v.) is less than that required to charge it. This drop in the electromotive force has led to the belief that the cell is not reversible. F. Dolezalek, however, has attributed the difference to mechanical hindrances, which prevent the equalization of acid concentration in the neighbourhood of the electrodes, rather than to any essentially irreversible chemical action. The fact that the Gibbs-Helmholtz equation is found to apply also indicates that the lead accumulator is approximately reversible in the thermodynamic sense of the term.
Polarization and Contact Diference of Potential.—If we connect together in series a single Daniell's cell, a galvanometer, and two platinum electrodes dipping into acidulated water, no visible chemical decomposition ensues. At first a considerable current is indicated by the galvanometer; the reflexion soon diminishes, however, and finally becomes very small. If, instead of using a single Daniell's cell, we employ some source of electromotive force which can be varied as we please, and gradually raise its intensity, we shall find that, when it exceeds a certain value, about 1.7 volt, a permanent current of considerable strength flows through the solution, and, after the initial period, shows no signs of decrease. This current is accompanied by chemical decomposition. Now let us disconnect the platinum plates from the battery and join them directly with the galvanometer. A current will flow for a while in the reverse direction; the system of plates and acidulated water through which a current has been passed, acts as an accumulator, and will itself yield a current in return. These phenomena are explained by the existence of a reverse electromotive force at the surface of the platinum plates. Only when the applied electromotive force exceeds this reverse force of polarization, will a permanent steady current pass through the liquid, and visible chemical decomposition proceed. It seems that this reverse electromotive force of polarization is due to the deposit on the electrodes of minute quantities of the products of chemical decomposition. Differences between the two electrodes are thus set up, and, as we have seen above, an electromotive force will therefore exist between them. To pass a steady current in the direction opposite to this electromotive force of polarization, the applied electromotive force ${\displaystyle {\text{E}}}$ must exceed that of polarization ${\displaystyle {\text{E}}',}$ and the excess ${\displaystyle {\text{E}}-{\text{E}}'}$ is the effective electromotive force of the circuit, the current being, in accordance with Ohm's law, proportional to the applied electromotive force and represented by ${\displaystyle ({\text{E}}-{\text{E}}')/{\text{R}},}$ where ${\displaystyle {\text{R}}}$ is a constant called the resistance of the circuit.
When we use platinum electrodes in acidulated water, hydrogen and oxygen are evolved. The opposing force of polarization is about 1.7 volt, but, when the plates are disconnected and used as a source of current, the electromotive force they give is only about 1.07 volt. This irreversibility is due to the work required to evolve bubbles of gas at the surface of bright platinum plates. If the plates be covered with a deposit of platinum black, in which the gases are absorbed as fast as they are produced, the minimum decomposition point is 1.07 volt, and the process is reversible. If secondary effects are eliminated, the deposition of metals also is a reversible process; the decomposition voltage is equal to the electromotive force which the metal itself gives when going into solution. The phenomena of polarization are thus seen to be due to the changes of surface produced, and are correlated with the differences of potential which exist at any surface of separation between a metal and an electrolyte.
Many experiments have been made with a View of separating the two potential-differences which must exist in any cell made of two metals and a liquid, and of determining each one individually. If we regard the thermal effect at each junction as a measure of the potential-difference there, as the total thermal effect in the cell undoubtedly is of the sum of its potential differences, in cases where the temperature coefficient is negligible, the heat evolved on solution of a metal should give the electrical potential-difference at its surface. Hence, if we assume that, in the Daniell's cell, the temperature coefficients are negligible at the individual contacts as well as in the cell as a whole, the sign of the potential-difference ought to be the same at the surface of the zinc as it is at the surface of the copper. Since zinc goes into solution and copper comes out, the electromotive force of the cell will be the difference between the two effects. On the other hand, it is commonly thought that the single potential differences at the surface of metals and electrolytes have been determined by methods based on the use of the capillary electrometer and on others depending on what is called a dropping electrode, that is, mercury dropping rapidly into an electrolyte and forming a cell with the mercury at rest in the bottom of the vessel. By both these methods the single potential-differences found at the surfaces of the zinc and copper have opposite signs, and the effective electromotive force of a Daniell's cell is the sum of the two effects. Which of these conflicting views represents the truth still remains uncertain.
Diffusion of Electrolytes and Contact Difference of Potential between Liquids.—An application of the theory of ionic velocity due to W. Nernst[7] and M. Planck[8] enables us to calculate the diffusion constant of dissolved electrolytes. According to the molecular theory, diffusion is due to the motion of the molecules of the dissolved substance through the liquid. When the dissolved molecules are uniformly distributed, the osmotic pressure will be the same everywhere throughout the solution, but, if the concentration vary from point to point, the pressure will vary also. There must, then, be a relation between the rate of change of the concentration and the osmotic pressure gradient, and thus we may consider the osmotic pressure gradient as a force driving the solute through a viscous medium. In the case of non electrolytes and of all non-ionized molecules this analogy completely represents the facts, and the phenomena of diffusion can be deduced from it alone. But the ions of an electrolytic solution can move independently through the liquid, even when no current flows, as the consequences of Ohm's law indicate. The ions will therefore diffuse independently, and the faster ion will travel quicker into pure water in contact with a solution. The ions carry their charges with them, and, as a matter of fact, it is found that water in contact with a solution takes with respect to it a positive or negative potential, according as the positive or negative ion travels the faster. This process will go on until the simultaneous separation of electric charges produces an electrostatic force strong enough to prevent further separation of ions. We can therefore calculate the rate at which the salt as a whole will difiuse by examining the conditions for a steady transfer, in which the ions diffuse at anlequal rate, the faster one being restrained and the slower one urged forward by the electric forces. In this manner the diffusion constant can be calculated in absolute units (HCl = 2.49, HNO3 = 2.27, NaCl= 1.12), the unit of time being the day. By experiments on diffusion this constant has been found by Scheffer, and the numbers observed agree with those calculated (HCl = 2.30, HNO3 = 2.22, NaCl = 1.11).
As we have seen above, when a solution is placed in contact with water the water will take a positive or negative potential with regard to the solution, according as the cation or anion has the greater specific velocity, and therefore the greater initial rate of diffusion. The difference of potential between two solutions of a substance at different concentrations can be calculated from the equations used to give the diffusion constants. The results give equations of the same logarithmic form as those obtained in a somewhat different manner in the theory of concentration cells described above, and have been verified by experiment.
The contact differences of potential at the interfaces of metals and electrolytes have been co-ordinated by Nernst with those at the surfaces of separation between different liquids. In contact with a solvent a metal is supposed to possess a definite solution pressure, analogous to the vapour pressure of a liquid. Metal goes into solution in the form of electrified ions. The liquid thus acquires a positive charge, and the metal a negative charge. The electric forces set up tend to prevent further separation, and finally a state of equilibrium is reached, when no more ions can go into solution unless an equivalent number are removed by voltaic action. On the analogy between this case and that of the interface between two solutions, Nernst has arrived at similar logarithmic expressions for the difference of potential, which becomes proportional to ${\displaystyle \log({\text{P}}_{1}/{\text{P}}_{2})}$ where ${\displaystyle {\text{P}}_{2}}$ is taken to mean the osmotic pressure of the cations in the solution, and ${\displaystyle {\text{P}}_{1}}$ the osmotic pressure of the cations in the substance of the metal itself. On these lines the equations of concentration cells, deduced above on less hypothetical grounds, may be regained.
Theory of Electrons.—Our views of the nature of the ions of electrolytes have been extended by the application of the ideas of the relations between matter and electricity obtained by the study of electric conduction through gases. The interpretation of the phenomena of gaseous conduction was rendered possible by the knowledge previously acquired of conduction through liquids; the newer subject is now reaching a position whence it can repay its debt to the older.
Sir J. J. Thomson has shown (see Conduction, Electric, § III.) that the negative ions in certain cases of gaseous conduction are much more mobile than the corresponding positive ions, and possess a mass of about the one-thousandth part of that of a hydrogen atom. These negative particles or corpuscles seem to be the ultimate units of negative electricity, and may be identified with the electrons required by the theories of H. A. Lorentz and Sir J. Larmor. A body containing an excess of these particles is negatively electrified, and is positively electrified if it has parted with some of its normal number. An electric current consists of a moving stream of electrons. In gases the electrons sometimes travel alone, but in liquids they are always attached to matter, and their motion involves the movement of chemical atoms or groups of atoms. An atom with an extra corpuscle is a univalent negative ion, an atom with one corpuscle detached is a univalent positive ion. In metals the electrons can slip from one atom to the next, since a current can pass without chemical action. When a current passes from an electrolyte to a metal, the electron must be detached from the atom it was accompanying and chemical action be manifested at the electrode.
Bibliography.—Michael Faraday, Experimental Researches in Electricity (London, 1844 and 1855; W. Ostwald, Lehrbuch der allgemeinen Chemie, 2te Aufl. (Leipzig, 1891); Elektrochemie (Leipzig, 1896); W Nernst, Theoretische Chemie, 3te Aufl: (Stuttgart, 1900; English translation, London, 1904); F. Kohlrausch and L. Holborn, Das Leitvermögen der Elektrolyte (Leipzig, 1898); C. D. Whetham, The Theory of Solution and Electrolysis (Cambridge, 1902); M. Le Blanc, Elements of Electrochemistry (Eng. trans., London, 1896); S. Arrhenius, Text-Book of Electrochemistry (Eng. trans., London, 1902); H. C. jones, The Theory of Electrolytic Dissociation (New York, 1900); N. Munroe Hopkins, Experimental Electrochemistry (London, 1905); Lüphe, Grundzüge der Elektrochemie (Berlin, 1896).
Some of the more important papers on the subject have been reprinted for Harper's Series of Scientific Memoirs in Electrolytic Conduction (1899) and the Modern Theory of Solution (1899). Several journals are published specially to deal with physical chemistry, of which electrochemistry forms an important part. Among them may be mentioned the Zeitschrift für physikalische Chemie (Leipzig); and the Journal of Physical Chemistry (Cornell University). In these periodicals will be found new work on the subject and abstracts of papers which appear in other physical and chemical publications.
1. See Hittorf, Pogg. Ann. cvi. 517 (1859).
2. Grundriss der Elektrochemie (1895), p. 292; see also F. Kaufler and C. Herzog, Ber., 1909, 42, p. 3858.
3. Brit. Ass. Rep., 1906, Section A, Presidential Address.
4. See Theory of Solution, by W. C. D. Whetham (1902), p. 328.
5. W. Ostwald, Zeits. physikal. Chemie, 1892, vol. ix. p. 579; T. Ewan, Phil. Mag. (5), 1892, vol. xxxiii. p. 317; G. D. Liveing, Cambridge Phil. Trans., 1900, vol. xviii. p. 298.
6. See W. B. Hardy, Journal of Physiology, 1899, vol. xxiv. p. 288; and W. C. D. Whetham Phil. Mag., November 1899.
7. Zeits. physikal. Chem. 2, p. 613.
8. Wied. Ann., 1890, 40, p. 561.
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https://www.ias.ac.in/listing/articles/pram/079/02
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• Volume 79, Issue 2
August 2012, pages 173-335
• Complex dynamical invariants for two-dimensional complex potentials
Complex dynamical invariants are searched out for two-dimensional complex potentials using rationalization method within the framework of an extended complex phase space characterized by $x = x_{1} + ip_{3}. y = x_{2} + ip_{4}, p_{x} = p_{1} + ix_{3}, p_{y} = p_{2} + ix_{4}$. It is found that the cubic oscillator and shifted harmonic oscillator admit quadratic complex invariants. THe obtained invariants may be useful for studying non-Hermitian Hamiltonian systems.
• Solitons and cnoidal waves of the Klein–Gordon–Zakharov equation in plasmas
This paper studies the Klein–Gordon–Zakharov equation with power-law nonlinearity. This is a coupled nonlinear evolution equation. The solutions for this equation are obtained by the travelling wave hypothesis method, $(G'/G)$ method and the mapping method.
• Parallel decoherence in composite quantum systems
For the standard quantum Brownian motion (QBM) model, we point out the occurrence of simultaneous (parallel), mutually irreducible and autonomous decoherence processes. Besides the standard Brownian particle, we show that there is at least another system undergoing the dynamics described by the QBM model. We do this by selecting the two mutually irreducible, global structures (decompositions into subsystems) of the composite system of the QBM model. The generalization of this observation is a new, challenging task in the foundations of the decoherence theory. We do not place our findings in any interpretational context.
• Relativistic models of a class of compact objects
A class of general relativistic solutions in isotropic spherical polar coordinates which describe compact stars in hydrostatic equilibrium are discussed. The stellar models obtained here are characterized by four parameters, namely, 𝜆, 𝑘, 𝐴 and 𝑅 of geometrical significance related to the inhomogeneity of the matter content of the star. The stellar models obtained using the solutions are physically viable for a wide range of values of the parameters. The physical features of the compact objects taken up here are studied numerically for a number of admissible values of the parameters. Observational stellar mass data are used to construct suitable models of the compact stars.
• The final outcome of dissipative collapse in the presence of 𝛬
We investigate the role played by the cosmological constant during gravitational collapse of a radiating star with vanishing Weyl stresses in the interior. We highlight the role played by the cosmological constant during the latter stages of collapse. The evolution of the temperature of the collapsing body is studied by employing causal heat transport equation. We show that the inclusion of the cosmological constant enhances the temperature within the stellar core.
• Quantum Jarzynski equality with multiple measurement and feedback for isolated system
In this paper, we derive the Jarzynski equality (JE) for an isolated quantum system in three different cases: (i) the full evolution is unitary with no intermediate measurements, (ii) with intermediate measurements of arbitrary observables being performed, and (iii) with intermediate measurements whose outcomes are used to modify the external protocol (feedback). We assume that the measurements will involve errors that are purely classical in nature. Our treatment is based on path probability in state space for each realization. This is in contrast with the formal approach based on projection operator and density matrices. We find that the JE remains unaffected in the second case, but gets modified in the third case where the mutual information between the measured values with the actual eigenvalues must be incorporated into the relation.
• Production parameters of the therapeutic 105Rh radionuclide using medium energy cyclotron
Production cross-sections of the therapeutic 105Rh radionuclide from proton-induced reactions on natural palladium target were measured using stacked-foil activation technique combined with high resolution 𝛾-ray spectrometry at the MC50 cyclotron of the Korea Institute of Radiological and Medical Sciences. Note that cyclotron production of the 105Rh radionuclide from natural palladium target was measured here for the first time. Results are compared with the theoretical values obtained using the model codes TALYS and ALICE-IPPE. Thick target integral yields for the investigated 105Rh radionuclide were deduced from the threshold energy to 40 MeV. Measured data of the 105Rh radionuclide are important because of its potential applications in nuclear medicine and/or therapeutic purposes. Optimal production circumstances for the therapeutic 105Rh radionuclide using a cyclotron are discussed elaborately.
• Measurement of 232Th$(n, \gamma)$ and 232Th$(n, 2n)$ cross-sections at neutron energies of 13.5, 15.5 and 17.28 MeV using neutron activation techniques
The 232Th$(n, \gamma)$ reaction cross-section at average neutron energies of 13.5, 15.5 and 17.28 MeV from the 7Li$(p, n)$ reaction has been determined for the first time using activation and off-line 𝛾-ray spectrometric technique. The 232Th$(n, 2n)$ cross-section at 17.28 MeV neutron energy has also been determined using the same technique. The experimentally determined 232Th$(n, \gamma)$ and 232Th$(n, 2n)$ reaction cross-sections from the present work were compared with the evaluated data of ENDF/BVII and JENDL-4.0 and were found to be in good agreement. The present data, along with literature data in a wide range of neutron energies, were interpreted in terms of competition between 232Th$(n, \gamma)$, $(n, f)$, $(n, nf)$ and $(n, xn)$ reaction channels. The 232Th$(n, \gamma)$ and 232Th$(n, 2n)$ reaction cross-sections were also calculated theoretically using the TALYS 1.2 computer code and were found to be in good agreement with the experimental data from the present work but were slightly higher than the literature data at lower neutron energies.
• Design of a 10 MeV, 352.2 MHz drift tube Linac
A conventional 10 MeV drift tube Linac is designed as a part of the $H^-$ front end accelerator system for the future Indian Spallation Neutron Source. The front end Linac consists of a 50 keV H- ion source, low energy beam transport (LEBT), a 3 MeV radio frequency quadrupole (RFQ), and a 10 MeV drift tube Linac (DTL), which will be operated at 1.25% duty factor. Cell geometry of the DTL is optimized to house quadrupole magnets and to get maximum effective shunt impedance. Transmission efficiency and various other output parameters depend on the input design parameters. Beam dynamic studies are done to maximize the transmission efficiency with minimum emittance growth. Errors in the alignment of the quadrupoles inside the drift tubes or the DTL tank alignment with respect to transport line will degrade the beam quality and may reduce the transmission efficiency. Error study is performed to assess the acceptable tolerances on various parameters. This paper describes the 2D and 3D electromagnetic and beam dynamics simulations of the 352.2 MHz, 10 MeV drift tube Linac. Details of the DTL design are reported in this paper.
• On wave characteristics of piezoelectromagnetics
This report gives a discussion of a new wave characteristic as a material parameter for a composite with the magnetoelectric effect. The new parameter depends on the material constants of a piezoelectromagnetic composite. It can be implemented on : (A) mechanically free, electrically and magnetically open surface and (B) mechanically free, electrically and magnetically closed surface. These theoretical investigations are useful for researches in the firlds of acousto-optics, photonics and opto-acousto-electronics. Some sample calculations are carried out for BaTiO3 - CoFe2O4 and PZT-5H-Terfenol-D composites of class $6 mm$. Also, the first and second derivatives of the new parameter with respect to the electromagnetic constant 𝛼 are graphically shown.
• Analytical model of transient temperature and thermal stress in continuous wave double-end-pumped laser rod: Thermal stress minimization study
A time-dependent analytical thermal model of the temperature and the corresponding induced thermal stresses in continuous wave double-end-pumped laser rod are derived from the first principle using the integral transform method. The aim of the paper is to study the effect of increasing the pumping powers while the laser crystals are still in the safe zone (i.e. far away from failure stress) and to suitably choose a crystal that achieves this task. The result of this work is compared with a well-verified finite element solution and a good agreement has been found. Some conclusions are obtained: Tm:YAP crystal, which has high thermal conductivity, low expansion coefficient, low absorption coefficient, low thermal factor and low product of $\gamma E/(1−\nu)$, is the best choice to reduce induced stress although it is responded and brought to thermal equilibrium faster than the other types of crystal usually used in the end-pumped solid-state laser.
• Calibration-free laser-induced breakdown spectroscopy for quantitative elemental analysis of materials
The application of calibration-free laser-induced breakdown spectroscopy (CF-LIBS) for quantitative analysis of materials, illustrated by CF-LIBS applied to a brass sample of known composition, is presented in this paper. The LIBS plasma is produced by a 355 nm pulsed Nd:YAG laser with a pulse duration of 6 ns focussed onto a brass sample in air at atmospheric pressure. The time-resolved atomic and ionic emission lines of Cu and Zn from the LIBS spectra recorded by an Echelle spectrograph coupled with a gated intensified charge coupled detector are used for the plasma characterization and the quantitative analysis of the sample. The time delay where the plasma is optically thin and is also in local thermodynamic equilibrium (LTE), necessary for the elemental analysis of samples from the LIBS spectra, is deduced. An algorithm relating the experimentally measured spectral intensity values with the basic physics of the plasma is developed. Using the algorithm, the Zn and Cu concentratioins in the brass sample are determined. The analytical result obtained from the CF-LIBS technique agree well with the certified valued of the elements in the sample, with an accuracy error < 1%
• Lekhnitskii’s formalism of one-dimensional quasicrystals and its application
By generalizing the complex potential approach developed by Lekhnitskii, plane problems of one-dimensional quasicrystals are solved first by using an octet formalism for which there are four pairs of comple roots; The approach uses a representation of stresses and proceeds by integration of the expressions for deformations and application of the anisotropic constitutive law and the compatibility of displacements. To illustrate its utility, the generalized lekhnitskii's formalism is used to analyse the coupled phonon and phason fields in an infinite quasicrystal medium containing an elliptic rigid inclusion.
• Collapse of a Bose gas: Kinetic approach
We have analytically explored the temperature dependence of critical number of particales for the collapse of a harmonically trapped attractively interacting Bose gas below the condensation point by introducing a kinetic approach within the Hartee-Fock approximation. The temperature dependence obtained by this easy approach is consistant with that obtained from the scaling theory.
• Electronic structure and equilibrium properties of hcp titanium and zirconium
The electronic structures of hexagonal-close-packed divalent titanium (3-d) and zirconium (4-d) transition metals are studied by using a non-local model potential method. From the present calculation of energy bands, Fermi energy, density of states and the electronic heat capacity of these two metals are determined and compared with the existing results in the literature.
• # Pramana – Journal of Physics
Current Issue
Volume 93 | Issue 5
November 2019
• # Editorial Note on Continuous Article Publication
Posted on July 25, 2019
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https://mattiaciollaro.github.io/brews/luigi-jupyter-notebook-task
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In a recent guest post on Intoli’s blog, I described the basics of using Luigi to build data science pipelines.
I also introduced the JupyterNotebookTask class that I wrote to run Jupyter notebooks as Luigi tasks.
Check out this and this.
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https://www.arxiv-vanity.com/papers/1005.5317/
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# The effect of activity-related meridional flow modulation on the strength of the solar polar magnetic field
J. Jiang1 , E. Işık2 , R.H. Cameron1 , D. Schmitt1 & M. Schüssler1
1affiliation: Max-Planck-Institut für Sonnensystemforschung, 37191 Katlenburg-Lindau, Germany
2affiliation: Department of Physics, Faculty of Science & Letters, İstanbul Kültür University, Ataköy Campus, Bakırköy 34156, İstanbul, Turkey
###### Abstract
We studied the effect of the perturbation of the meridional flow in the activity belts detected by local helioseismology on the development and strength of the surface magnetic field at the polar caps. We carried out simulations of synthetic solar cycles with a flux transport model, which follows the cyclic evolution of the surface field determined by flux emergence and advective transport by near-surface flows. In each hemisphere, an axisymmetric band of latitudinal flows converging towards the central latitude of the activity belt was superposed onto the background poleward meridional flow. The overall effect of the flow perturbation is to reduce the latitude separation of the magnetic polarities of a bipolar magnetic region and thus diminish its contribution to the polar field. As a result, the polar field maximum reached around cycle activity minimum is weakened by the presence of the meridional flow perturbation. For a flow perturbation consistent with helioseismic observations, the polar field is reduced by about 18% compared to the case without inflows. If the amplitude of the flow perturbation depends on the cycle strength, its effect on the polar field provides a nonlinearity that could contribute to limiting the amplitude of a Babcock-Leighton type dynamo.
Sun: activity, Sun: magnetic fields, Sun: meridional circulation
## 1 Introduction
Surface flux transport models treat the evolution of the large-scale magnetic field on the surface of the Sun (e.g., Wang et al., 1989; Schrijver, 2001; Mackay et al., 2002; Baumann et al., 2004). In such models, the evolution of the radial magnetic field at the solar surface is governed by the emergence of new flux in the form of bipolar magnetic regions and by advective transport through large-scale flows (differential rotation, meridional circulation) and supergranular turbulent diffusion. The well-known cyclic variations of differential rotation in the form of zonal flows (e.g., Howard & Labonte, 1980; Howe et al., 2006) so far have not been considered in flux transport simulations. On the other hand, variations in the large-scale meridional flow (Komm et al., 1993; Basu & Antia, 2003; Hathaway & Rightmire, 2010) have been considered in flux-transport simulations by assuming cycle-to-cycle changes in the overall amplitude of the flow (Wang et al., 2002a; Dikpati et al., 2004; Wang et al., 2009).
Another cycle-related modulation of the surface flow field is the modulation of the axisymmetric component of the meridional flow in the form of bands of latitudinal velocity centered on the dominant latitudes of magnetic activity, first detected at depths greater than 20 Mm (Chou & Dai, 2001; Beck et al., 2002). In the case of near-surface flows, the residual meridional flow velocities (after subtraction of the mean flow) during cycle 23 were of the order of 35 ms and converge toward the dominant latitudes of magnetic activity while migrating towards the equator in parallel to the activity belts (Gizon & Rempel, 2008; González Hernández et al., 2008, 2010). These flows are probably related to the meridional motions of sunspots and pores (Ribes & Bonnefond, 1990, and references therein) and other magnetic features (Komm, 1994; Meunier, 1999). The cumulative effect of the near-surface horizontal flows converging towards active regions (e.g., Haber et al., 2004; Hindman et al., 2004) appear to contribute to the axisymmetric meridional flow perturbation (Gizon, 2004; González Hernández et al., 2008), but there is evidence that at least part of this perturbation is unrelated to surface activity (González Hernández et al., 2010).
The effect of the near-surface inflows on the evolution of single active regions was recently studied by De Rosa & Schrijver (2006). Considering results obtained with a surface flux transport model (cf. Schrijver, 2001), these authors find that inflows of the order of ms significantly affect the dispersal of magnetic flux from an isolated active region. These results indicate that the axisymmetric meridional flow perturbations associated with the activity belts could also affect the evolution of the solar surface field on a global scale. Particularly interesting in this connection is the effect on the polar field strength, which is an important source of the heliospheric field and also plays a significant role in Babcock-Leighton-type dynamo models. Here we present results of solar-cycle simulations using the flux transport code of Baumann et al. (2004), including axisymmetric bands of converging latitudinal flows centered on the migrating activity belts. The aim of this work is to study the general effect of these flows on the evolution of the solar surface field, and particularly on the strength of the polar field. This is an exploratory study focussing on understanding the physical mechanisms; we do not intend to reproduce any actual solar data. We need not consider the zonal flows in this study because the buildup of magnetic field to the Sun’s poles is dominated by the latitude separation of the polarities of a bipolar magnetic region and thus essentially is an axisymmetric problem (Cameron & Schüssler, 2007); zonal flows (and differential rotation in general, see Leighton:1964) have no effect on the amount of signed flux reaching the poles.
This paper is organized as follows. The flux transport model is described in Section 2. The relevant effects of the latitudinal flow bands on the surface flux evolution are illustrated with simulations of single bipolar regions in Section 3. The results of full solar-cycle simulations are presented in Section 4, which includes a study of the dependence of the polar field on various model parameters. The implication of our results are discussed in Section 5.
## 2 Flux-transport model
The induction equation considered in our flux transport model is given by (for details see Baumann et al., 2004; Jiang et al., 2009, 2010)
∂B∂t= −Ω(λ,t)∂B∂ϕ−1R⊙cosλ∂∂λ[v(λ,t)Bcosλ] (1) +ηH[1R2⊙cosλ∂∂λ(cosλ∂B∂λ)+1R2⊙cos2λ∂2B∂ϕ2] +S(λ,ϕ,t)+D(ηr),
where and are longitude and latitude, respectively, is the radial component of the magnetic field, is the rotational velocity, is the meridional flow velocity, is the turbulent surface diffusivity due to the random granular and supergranular velocity field, is a source term which describes the emergence of new flux, and the term models the radial diffusion of the field (Baumann et al., 2006) with the diffusivity parameter set to kms. We use the synodic rotation rate (in degrees per day) determined by Snodgrass (1983) and take kms.
The meridional flow velocity consists of a background flow plus a perturbation, , representing axisymmetric bands of converging latitudinal flow (one per hemisphere), viz.
v(λ,t)={vmsin(2.4λ)+Δv(λ,t)% for\ |λ|≤75∘0otherwise, (2)
where ms and
Δv(λ,t)=⎧⎪⎨⎪⎩v0sin[(λ−λc(t))/Δλυ]for\ −180∘≤(λ−λc(t))/Δλυ<180∘0otherwise. (3)
The bands of perturbed meridional flow are characterized by their velocity amplitude, , their width, , and their central latitude, . The equatorward migration of the bands in the course of the solar cycle is represented by the time dependence of (see Section 4.1). Note that Equation (3) describes one band, its counterpart on the other hemisphere is obtained by changing . For sufficiently small central latitudes, the two bands can overlap and the corresponding velocities are added.
## 3 Evolution of single bipolar magnetic regions
In order to illustrate the effect of the meridional flow perturbation on the latitudinal flux transport as the source of the polar field, we first study a single bipolar magnetic region (BMR). The temporal evolution of the corresponding surface flux depends on the relative position of the bands of latitudinal flow perturbation and the emergence latitude. We consider the evolution of a BMR that emerges at at a latitude of on the northern hemisphere under the influence of four different meridional flow patterns (see Figure 1) described by Eqs. (2) and (3). The initial flux distribution of the BMR is chosen following the approach of Baumann et al. (2004).
Snapshots of the surface distribution of the magnetic field are shown in Figure 2. The four cases shown correspond to no flow perturbation (top row) and to converging flow bands centered on different latitudes . The corresponding time evolution of the polar fields is shown in Figure 3. When the flow perturbation is centered equatorward of the BMR emergence latitude (, second row in Figure 2), the overlap of the flow perturbations from both hemispheres (see blue curve in Figure 1) has the consequence that preceding and following polarities of the BMR experience an increased latitude separation: the leading polarity is advected toward the equator while the following polarity is less affected. As a consequence, the latitudinal separation between preceding and following polarity increases, so that the polar field becomes stronger in comparison to the case without flow perturbation. The opposite effect results in the case (third row in Figure 2, red curves in Figs. 1 and 3): now the latitudinal gradient of the meridional flow at the emergence location is such that the two polarities are now advected towards each other, thus reducing the azimuthally averaged field and, consequently, the flux reaching the pole. In the third case (, fourth row in Figure 2, green curves in Figs. 1 and 3), there are two opposing effects: the meridional flow gradient near the emergence location tends to separate the polarities while the following polarity experiences an overall decrease of its poleward advection, thus tending to reduce the azimuthally averaged field. The net effect is a slight reduction of the contribution to the polar field.
These results show that the emergence location of a BMR relative to the position of the bands of flow perturbation is important for its effect on the development of the polar field. Note that the (axisymmetric) meridional flow perturbation considered here results from the cumulative effect of the individual inflows. A given active region (which can appear anywhere in the activity belt) therefore experiences the superposition of these inflows, which needs not necessarily be centered on this active region.
## 4 Simulation of activity cycles
### 4.1 Cycle parameters
As next step, we consider sequences of simulated activity cycles by periodically varying the number of BMRs that appear on the surface. The emerging BMRs have a tilt angle of half their emergence latitude, follow Hale’s polarity rules, and are introduced in activity belts that migrate toward the equator. The BMR area, , follows the distribution derived from observations (Schrijver & Harvey, 1994). The number of BMRs emerging during the cycle is taken to vary proportional to a Gaussian time profile, viz.
ni(t) ∝ {exp{−[(t−ti+6.5)/3.25]2}0≤(t−ti)≤130otherwise (4)
where is the starting time of the cycle and all times are in years. With new cycles starting every 11 years and having a duration of 13 years we thus take into account the overlap of solar activity cycles. The emergence of new BMRs occurs randomly with a Gaussian distribution of half-width about the central latitudes of the activity belts, , which migrate equatorward according to
λ±(t) = ±[λ0−(λ0−8∘)(t−ti)/13], (5)
so that the belts progress from their starting latitudes, , to in the course of 13 years. The resulting emergence pattern of new BMRs (butterfly diagram) for and is shown in Figure 4.
The latitudinal bands of the meridional flow perturbation move in parallel to the active region belts, their central latitudes (on both hemispheres), , coinciding with the centers of the corresponding activity belts, . We do not assume an overlap of the meridional flow perturbations from consecutive cycles; therefore, we include the flow perturbation only for 11 years, starting from the third year of each 13-year cycle. Since the early flux emergence at mid latitudes affects the polar field only little, this assumption does not influence the results in a significant way (see also Section 4.4).
### 4.2 Dependence on the flow perturbation parameters
Figure 5 shows the cyclic variation of the polar fields for three values of the flow perturbation amplitude: ms. The latitudinal width of the bands was kept fixed at and the activity belt parameters were and . As already suggested by the results of the study of single BMRs shown in Section 3, we find that the net effect of the flow perturbation on BMRs emerging in an extended activity belt is a reduction of the polar field amplitudes. The effect becomes more pronounced with increasing flow perturbation amplitude.
On a more quantitative level, the dependence of the mean polar field amplitude (averages over three consecutive cycles)111We omit the first two simulated cycles from the analysis as these could be affected by the arbitrary initial magnetic field. With kms, the -folding time of the magnetic field in the absence of sources (and thus the ‘memory’ of the system) is of about 5 years. on the width, , and the amplitude, , of the flow perturbation is given in Table 1. The numbers in parentheses give the percentage change of the polar field with respect to the case with unperturbed meridional flow. In all cases we find a reduction of the polar field. For parameters roughly corresponding to the helioseismic results ms, , the flow perturbation leads to a reduction of the polar field amplitude by about 18% with respect to the same case but without flow perturbation. Apart from the reduction becoming more pronounced with increasing perturbation amplitude, it also is stronger for bigger , i.e., for wider bands of perturbed flow. This is plausible because wider flow bands affect a larger proportion of the BMRs emerging in the activity belts and, at the same time, influence latitudinal flux advection for a longer time. In all cases, the evolution of the total unsigned surface flux is almost unaffected by the presence of the flow perturbation.
### 4.3 Dependence on the activity belt parameters
Keeping the parameters of the meridional flow perturbation fixed at values of ms and , we also considered the dependence of the polar field amplitude on the starting latitude, , and the width, , of the activity belt. The results are summarized in Table 2. As already suggested by the results of Section 3, the biggest effect on the polar field occurs when BMRs always emerge near the center (latitude of convergence) of the bands of perturbed flow, i.e., for . The flow perturbation then always tends to decrease the latitude extent of the BMR and thus reduces its azimuthally averaged field. The broader the activity belt (relative to the band of perturbed flow), the smaller is the effect on the polar field. On the other hand, for a given activity belt width, the variation of the starting latitude, , of the activity belt in a cycle does not significantly change the effect of the flow perturbation. In most cases, there is a tendency for the polar field amplitude to decrease with increasing . This result may have implications for the nonlinear limitation of a Babcock-Leighton dynamo as further discussed in Section 5.
### 4.4 Time-dependent flow perturbation amplitude
The observations based on helioseismology indicate that the amplitude of the axisymmetric flow perturbation peaks around the maximum of magnetic activity (González Hernández et al., 2010). We therefore also considered the effect of a temporal variation of the flow perturbation in parallel to the activity level. To this end, we modulated the perturbation amplitude, , with the same time profile as that assumed for the number of emerging BMRs given by Equation (4), so that the maximum speed is reached at activity maximum. With the previously used parameters for the flow perturbation (, ) and for the width of the activity belt (), this results in a polar field with an amplitude (three-cycle average) of 5.66 G, about 2.5% higher than the value of 5.52 G found for constant flow perturbation amplitude. The effect of the time variation is somewhat stronger if we assume zero spread of the activity belt (); in this case we obtain a polar field of 5.22 G, which is about 6% higher than the corresponding value of 4.92 G for constant flow perturbation amplitude. This is to be expected since the polar field is dominated by the trans-equatorial transport (or cancellation) of leading-polarity flux; therefore, in the case of very narrow activity belts, the late phase of a cycle with flux emergence near the equator contributes more strongly to the strength of the polar field (Cameron & Schüssler, 2007).
Altogether, the effect of a temporal variation of the inflow amplitude is found to be rather small. Since the temporal modulation strongly reduces the flow perturbation during the rise and decay phases of a cycle, this result implies that the influence of the meridional flow perturbation on the polar field is dominated by the period around activity maximum.
## 5 Discussion and conclusion
The results presented here show that the observed cycle-related meridional flow perturbations in the form of bands migrating with the activity belts decrease the strength of the polar fields resulting from the latitudinal transport of surface flux. For a flow perturbation corresponding to the helioseismic observations, this reduction amounts to about 18% with respect to the case without flow perturbation. This indicates that these effects should be taken into account in surface flux transport simulations aiming at a quantitative pre- or postdiction of the polar field strength.
It is doubtful whether this kind of flow perturbation could have significantly contributed to the low polar polar field strength during the activity minimum between solar cycles 23 and 24 (e.g., Schrijver & Liu, 2008) as compared to previous minima: the perturbation is probably present during every cycle, so that only an increase of the perturbation in cycle 23 compared to its amplitude in previous cycles would contribute to a comparatively weaker polar field during the recent minimum. In any case, other effects must have been affecting the polar field in addition since the observed reduction by nearly a factor of 2 exceeds the decrease that could be caused by the flow perturbation considered here.
The observed variation of the flow perturbation amplitude during the activity cycle (González Hernández et al., 2010) and the probable contribution of the near-surface inflows toward active regions to the driving of the perturbations (Gizon & Rempel, 2008) suggest that the amplitude of the flow perturbation should increase with cycle strength. According to our results, this would lead to a stronger reduction of the polar field built up during cycles of higher activity. Since, in the framework of a Babcock-Leighton dynamo, the polar field is a measure of the poloidal field providing the basis for the toroidal field in the subsequent cycle, the meridional flow perturbation is potentially important for the nonlinear modulation and limitation of the cycle amplitude. Furthermore, we have also seen that the polar field decreases for increasing starting latitude, , of the activity belt at the beginning of a cycle. Since stronger cycles typically have higher values of (Solanki et al., 2008), this relationship would strengthen the nonlinear effect of the flow perturbation in the subsequent cycle amplitude.
We conclude that, in addition to global variations of the meridional flow speed (Wang et al., 2002a, b), the cyclic perturbation of the meridional flow by converging bands migrating with activity belts has an appreciable effect on the build-up of the magnetic field at the polar caps. Its relation to the strength of a cycle means that the flow perturbation could be an important factor in determining the amplitude of Babcock-Leighton-type flux transport dynamos.
## References
If you find a rendering bug, file an issue on GitHub. Or, have a go at fixing it yourself – the renderer is open source!
For everything else, email us at [email protected].
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# 30^30*29^29*28^28*...*2^2*1^1 = n. How many zeroes does ‘n’ contain at
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30^30*29^29*28^28*...*2^2*1^1 = n. How many zeroes does ‘n’ contain at [#permalink]
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12 Nov 2017, 01:48
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$$30^{30} * 29^{29} * 28^{28}*...*2^2 * 1^1 = n$$. How many zeroes does ‘n’ contain at the end of the number (to the right of the last non-zero digit)?
A. 30
B. 60
C. 63
D. 105
E. 130
[Reveal] Spoiler: OA
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Re: 30^30*29^29*28^28*...*2^2*1^1 = n. How many zeroes does ‘n’ contain at [#permalink]
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The original expression can be rewritten as $$\frac{30!^{30}}{29!*28!*27!*...*3!*2!*1!}$$.
Using the forumla for factorials and the trailing zeroes:
$$\frac{30}{5} + \frac{30}{25} = 7$$
7 trailing zeroes for 30!, so the numerator has 210 zeroes.
Denominator has, using the same approach:
6 for 29!, 28!, 27!, 26! and 25!
4 for 24!, 23!, 22!, 21! and 20!
3 for 19!, 18!, 17!, 16! and 15!
2 for 14!, 13!, 12!, 11! and 10!
1 for 9!, 8!, 7!, 6! and 5!
0 for 4!, 3!, 2! and 1!.
Product of numbers with trailing zeroes makes these zeroes add up, then the resulting tally of zeroes in the denominator is: $$5*(6+4+3+2+1) = 5*16 = 80$$
Division with trailing zeroes makes you subtract the total of trailing zeroes in the denominator from the total of trailign zeroes in the numerator
$$210 - 80 =130$$
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Re: 30^30*29^29*28^28*...*2^2*1^1 = n. How many zeroes does ‘n’ contain at [#permalink]
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12 Nov 2017, 03:22
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Count the number of 5's to get the number of Zeroes
Only 5,10,15,20,25,30 contains 5's
30^30 has 30 5's
25^25 has 50 5's
20^20 has 20 5's
15^15 has 15 5's
10^10 has 10 5's
5^5 has 5 5's
So the total is 130
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Re: 30^30*29^29*28^28*...*2^2*1^1 = n. How many zeroes does ‘n’ contain at [#permalink]
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12 Nov 2017, 04:33
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Bunuel wrote:
$$30^{30} * 29^{29} * 28^{28}*...*2^2 * 1^1 = n$$. How many zeroes does ‘n’ contain at the end of the number (to the right of the last non-zero digit)?
A. 30
B. 60
C. 63
D. 105
E. 130
Number of 10s will depend on number of 2s and 5s
Here since 5 is the larger prime number, it will give us the number of 0s
So number involving 5 are $$30^{30}*25^{25}*20^{20}*15^{15}*10^{10}*5^5=5^{30}*(5^2)^{25}*5^{20}*5^{15}*5^{10}*5^5=5^{30+2*25+20+15+10+5}=5^{130}$$
Ans 130
E
_________________
Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
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Re: 30^30*29^29*28^28*...*2^2*1^1 = n. How many zeroes does ‘n’ contain at [#permalink]
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12 Nov 2017, 05:32
To find the no. of zeros find either
1) no. of 5's in the series( as 5*2 =10 makes the zero)
2) if a no. contains the zeros itself (like 30, 20 and 10 in above series)
In the above series we have enough two's, all even no(28,26,24....2) will provide us the two. We have to only look for the 5's and that will come from 5, 15,25.
in 5^5 gives 5 5's
in 15^5 gives 15 5's
in 25^5 gives 50 5's
therefore total- 70 5's i.e. 70 zeros.
also, if a no. contain a zero itself when multiply itself it will have the no. of zeros equals to( no. of zeros in the no. at the right end)* (power of that no).
30^30 will give 30 zeros.
20^20 will give 20 zeros
10^10 will give 10 zeros
Total- 60 zeros
Overall we have then 60+70= 130 zeros.
Also see the attachment for more detail
Please hit the kudos button if you like this
Attachments
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IMG_1.jpg [ 1.72 MiB | Viewed 550 times ]
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Re: 30^30*29^29*28^28*...*2^2*1^1 = n. How many zeroes does ‘n’ contain at [#permalink]
### Show Tags
13 Nov 2017, 07:20
Bunuel wrote:
$$30^{30} * 29^{29} * 28^{28}*...*2^2 * 1^1 = n$$. How many zeroes does ‘n’ contain at the end of the number (to the right of the last non-zero digit)?
A. 30
B. 60
C. 63
D. 105
E. 130
Can someone explain this question in most easiest way???
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Re: 30^30*29^29*28^28*...*2^2*1^1 = n. How many zeroes does ‘n’ contain at [#permalink]
### Show Tags
13 Nov 2017, 12:18
rocko911 wrote:
Bunuel wrote:
$$30^{30} * 29^{29} * 28^{28}*...*2^2 * 1^1 = n$$. How many zeroes does ‘n’ contain at the end of the number (to the right of the last non-zero digit)?
A. 30
B. 60
C. 63
D. 105
E. 130
Can someone explain this question in most easiest way???
Question is asking how many zeros will come at the right end if we mutiply the above series.
Suppose if we multiple : 101*100 then 10100 will be d answer and u can see before any digit other than zero appear we already have two zero at the right end .... So answer for this is two zeros....
Similarly for the above series we have to find how many continous zeros will come at right side before any other digit will appear ....
For d logic you can see the attached image ...
Just remember if we multiply any no. Than zero in the end will come if either the no. Has zero at the end in it like 10, 20, 300,. 400,....
Or if a the multiplying no. Has factor of 10 i.e one 5's and one 2's .... As 5*2 gives us 10
Eg 75 *8 ( in 75 we have 2 5's ( 3*5*5) and in 8 we have 3 tow's ) but we have only 2 fives and 3 twos so no. Of zero will come in the end is two)
75*8 = 600...
See above attachment and hit the kudos if u like this thanks
Sent from my Redmi Note 4 using GMAT Club Forum mobile app
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Re: 30^30*29^29*28^28*...*2^2*1^1 = n. How many zeroes does ‘n’ contain at [#permalink] 13 Nov 2017, 12:18
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http://math.stackexchange.com/tags/abstract-algebra/hot
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# Tag Info
## Hot answers tagged abstract-algebra
6
Take $G = H \times H \times H \times \cdots$ for $H$ any nontrivial group.
2
Let $G = \mathbb Z ^ \mathbb N$ (with pointwise addition as the product). Then let $f:G \times G \longrightarrow G$ be $$f(g,h)(n) = \begin{cases} g(k), &n = 2k \\ h(k), &n = 2k+1 \end{cases}$$ You can verify $f$ is an isomorphism.
2
For $n\in\mathbb Z$ and group $G$ denote $r_n(G)=\{g\in G:g^n=1\}$. Obviously, if $G$ abelian group, then $r_n(G)\leq G$. Group of invertible elements of the ring $R$ denote $R^*$. We can say, that we are looking for $|r_{m-1}(\mathbb{Z}_m^*)|$. Denote $n=m-1$. By the chinese remainder theorem, $$\mathbb{Z}_m^* \simeq ... 2 Given any matrix M\in \mathbb R^{m\times n} define a function T:\mathbb R^n\to \mathbb R^m as T(v)=Mv for all v\in \mathbb R^n. It is your exercise to show that T is well-defined (hence a function) and a linear transformation. 2 Yes, the elements of$$R := \Bbb Z [x] / \langle (x - 1) (x - 2) \rangle$$"look like" a + bx, a, b \in \Bbb Z. Put more precisely, each element of R has a unique representative in \Bbb Z of degree \leq 1, like you say exactly because of the division algorithm. This identification alone, however, does not determine the ring structure. The additive ... 2 They are not isomorphic. In (\mathbb Q\setminus \{0\},\cdot) you have an element that is its own inverse (-1). This does not happen in (\mathbb Z,+) 2 No. (\Bbb Z, +) is generated by \{1,-1\} and (\Bbb Q^\times, \cdot) is not finitely generated. 2 The Grothendieck group \mathcal{G}(M) of a commutative monoid M is the unique commutative group satisfying the following universal property: there is a monoid morphism i\colon M \to \mathcal{G}(M) such that for every monoid morphism f \colon M \to G, where G is a commutative group, there is a unique group morphism \mathcal{G}(f) \colon ... 2 Suppose that your regular polygon has a vertice on the x-axis. Then the first vertice counted counter clock wise has coordinates (\cos(\frac{2\pi}{n}),\sin(\frac{2\pi}{n})). Hence if you know the construction of the polygon, by projecting the first vertice on the x axis, which can be done with a ruler and a compass, you can get \cos(\frac{2\pi}{n}). ... 1 The proposition can be reformulated as if \mathfrak{a}+\mathfrak{b}=(1), then \mathfrak{a}\cap\mathfrak{b}=\mathfrak{a}\mathfrak{b} The word “provided” is used in the sense of “when it is given that”. In your case \mathfrak{a}+\mathfrak{b}=(2)+(2)=(2)\ne(1). 1 If a=b, then a^2+ab+b^2=3a^2=a^2=0 and a=0=b, we are done. Suppose that a\neq b. Observe that 0=(a-b)(a^2+ab+b^2)=a^3-b^3. Thus, a^3=b^3. We claim that a=0 and b=0. If a\neq 0, then (a^{-1}b)^3=1 and the multiplicative order of a^{-1}b in the multiplicative group F-\{0\} is 1 because 3\not\mid |F-\{0\}|=2^n-1. Hence, ... 1 aL=0 and bN=0 implies (ab)x=0 for all x\in M: 1 Let G=p_1^{a_1}p_2^{a_2}\cdots p_n^{a_n}, where p_1<p_2<\cdots<p_n are distinct primes and a_i\geq 1 for all i. Let N_p denote the number of Sylow p-subgroups and let N denote the total number of Sylow subgroups, i.e. the sum of all N_{p_i}. By the fact that N_p\equiv 1\pmod{p} and N_p||G| we must have that$$N_{p_i}\leq ...
1
I guess (from the comment discussion mostly) your question is not really about free objects but rather: given an adjunction $F \dashv U$, how can I explicitly write the bijection $\hom(FA, B) \to \hom(A, UB)$ so that the special case $\mathsf{Set} \leftrightarrows \mathsf{Grp}$ gives me the restriction $\varphi \mapsto \varphi\restriction A$? Given $F ... 1 From a computational point of view it amounts to saying that, each time you meet$x^2$, you can replace it with$3x-2$,$x^3$will be replaced with$\,3x^2-2x=7x-6$, &c. 1 I like the rest above, so I just wanted to suggest an argument for b). Suppose there is an$\overline{x} \in G/P$with order$p$, then$(x+P)^p=P$. But this means$x^p \in P$, so$(x^p)^{p^k}=e$for some$k$. But this means$x\in P$and thus$\overline{x}$is actually the identity in$G/P$. But the identity cannot have order$p$, so this is not possible. ... 1 Showing a subgroup isn't too bad. Note$P$is nonempty as$e\in P$. Also,$a_1,a_2\in P$with$p^k,p^m$such that$a^{p^k}=e=a^{p^m}$and$(a_1a_2^{-1})^{p^{m+k}}=e$since$G$is abelian. If some element$\bar{x}$was of order$p$in$G/P$, then$x\in P$so$\bar{x}=e\in G/P$. If$|P|\neq p^n$, then$G/P$has an element of order$p^k$for some$k$by ... 1 You found an$a\in\mathbb Z$such that$p\mid a^2+1$. If$p$is prime in$\mathbb Z[i]$then, from$p\mid a^2+1$you get$p\mid a+i$or$p\mid a-i$, and both cases lead to a contradiction. This shows that$p$isn't prime in$\mathbb Z[i]$. Then$p=(m+ni)(m-ni)$, so$p=m^2+n^2$. Now just take the ideal generated by$m+ni$. 1 $$\dfrac{|x+3|+x}{x+2} >1$$ Assume$x\le -3$$$\dfrac{|x+3|+x}{x+2} >1\iff\dfrac{-(x+3)+x}{x+2} >1\iff -(x+3)+x<x+2\iff-5<x$$ So the first interval is indeed$(-5,-3]$Now let$-3\le x < -2$$$\dfrac{|x+3|+x}{x+2} >1\iff\dfrac{+(x+3)+x}{x+2} >1\iff +(x+3)+x<x+2\iff x<-1$$ So the second interval is$[-3,-2)$Now$x>-2$... 1 Let$G$be the trivial group, for the only finite example. 1 Put in very simple terms, as polynomials two polynomials are equal if and only if all their coefficients are the same. So in$\Bbb Z_3[x]$, we have:$x^8 + 1 \neq x^3 + 1$, because the coefficient of$x^8$in the first is$1$, but the coefficient of$x^8$is$0$in the second (it has no$x^8$term). However, in$\Bbb Z_3$, we do have an$a \in \Bbb Z_3$... 1$\mathbb{Z_6}[X]/(2x+4)\simeq\mathbb{Z_2}[X]/(2x+4)\times\mathbb{Z_3}[X]/(2x+4)\simeq\mathbb{Z_2}[X]\times\mathbb{Z_3}\$
Only top voted, non community-wiki answers of a minimum length are eligible
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https://codegolf.stackexchange.com/questions/88979/can-you-outgolf-me-cops-section/90448
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# Cops section
The robbers section can be found here.
Thanks to FryAmTheEggman, Peter Taylor, Nathan Merrill, xnor, Dennis, Laikoni and Mego for their contributions.
### Challenge
Your task is to write 2 different programs (full programs/functions/etc.) in the same language and the same version (e.g. Python 3.5 ≠ Python 3.4, so that is not allowed), and when given n (using STDIN/function arguments/etc.), compute a(n) where a is an OEIS sequence of your choice. One of those programs is shorter than the other. You only need to submit the longer program of the two. The other one needs to be saved in case of not being cracked after 7 days. Your submission is cracked when your program has been outgolfed (whether it is by 1 byte or more).
For example, if the task you chose was to perform 2 × n, this could be a valid submission (in Python 2):
## Python 2, 16 bytes, score = 15 / 16 = 0.9375
print(2*input())
Computes A005843, (offset = 0).
If your submission has been cracked, then you need to state that in your header like so:
## Python 2, 16 bytes, score = 15 / 16 = 0.9375, [cracked] + link
print(2*input())
Computes A005843, (offset = 0).
### Offset
This can be found on every OEIS page. For example, for A005843, the offset is 0,2. We only need to use the first one, which is 0. This means that the function is defined for all numbers ≥ 0.
In other words, the function OEIS(n) starts with n = 0. Your program needs to work for all cases given by OEIS.
### Scoring
The score you get for your submission is equal to the following formula:
Score = Length (in bytes) of secret code ÷ Length (in bytes) of public code
The example above has the score 15 ÷ 16 = 0.9375.
The submission with the lowest score wins. Only submissions that have posted their solution will be eligible for winning.
### Rules
• The task you need to do is an OEIS sequence of your choice.
• Given n, output OEIS(n). Deviation is not allowed, so you need to produce the exact same sequence (when given n, you need to output OEIS(n)).
• Submissions that are not cracked within a period of 7 days are considered safe after the solution has been posted (submissions older than 7 days that do not have their solution posted are still vulnerable in being cracked).
• In your submission, you need to post the following things: language name, byte count, full code, so no pastebin links etc. (to prevent answers like Unary), OEIS sequence, score with lengths of both programs and additionally, the encoding that is used.
• Note: the same sequence cannot be posted twice in the same language. (For example, if the sequence A005843 has been done in Pyth, you cannot use Pyth again for that same sequence.)
• Input and output are both in decimal (base 10)
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script><style>table th,table td{padding: 5px;}th{text-align: left;}.score{text-align: right;}table a{display: block;}.main{float: left;margin-right: 30px;}.main h3,.main div{margin: 5px;}.message{font-style: italic;}#api_error{color: red;font-weight: bold;margin: 5px;}</style> <script>QUESTION_ID=88979;var safe_list=[];var uncracked_list=[];var n=0;var bycreation=function(x,y){return (x[0][0]<y[0][0])-(x[0][0]>y[0][0]);};var byscore=function(x,y){return (x[0][1]>y[0][1])-(x[0][1]<y[0][1]);};function u(l,o){jQuery(l[1]).empty();l[0].sort(o);for(var i=0;i<l[0].length;i++) l[0][i][1].appendTo(l[1]);if(l[0].length==0) jQuery('<tr><td colspan="3" class="message">none yet.</td></tr>').appendTo(l[1]);}function m(s){if('error_message' in s) jQuery('#api_error').text('API Error: '+s.error_message);}function g(p){jQuery.getJSON('//api.stackexchange.com/2.2/questions/' + QUESTION_ID + '/answers?page=' + p + '&pagesize=100&order=desc&sort=creation&site=codegolf&filter=!.Fjs-H6J36w0DtV5A_ZMzR7bRqt1e', function(s){m(s);s.items.map(function(a){var he = jQuery('<div/>').html(a.body).children().first();he.find('strike').text('');var h = he.text();if (!/cracked/i.test(h) && (typeof a.comments == 'undefined' || a.comments.filter(function(b){var c = jQuery('<div/>').html(b.body);return /^cracked/i.test(c.text()) || c.find('a').filter(function(){return /cracked/i.test(jQuery(this).text())}).length > 0}).length == 0)){var m = /^\s*((?:[^,;(\s]|\s+[^-,;(\s])+).*(0.\d+)/.exec(h);var e = [[n++, m ? m[2]-0 : null], jQuery('<tr/>').append( jQuery('<td/>').append( jQuery('<a/>').text(m ? m[1] : h).attr('href', a.link)), jQuery('<td class="score"/>').text(m ? m[2] : '?'), jQuery('<td/>').append( jQuery('<a/>').text(a.owner.display_name).attr('href', a.owner.link)) )];if(/safe/i.test(h)) safe_list.push(e);else uncracked_list.push(e);}});if (s.items.length == 100) g(p + 1);else{var s=[[uncracked_list, '#uncracked'], [safe_list, '#safe']];for(var i=0;i<2;i++) u(s[i],byscore);jQuery('#uncracked_by_score').bind('click',function(){u(s[0],byscore);return false});jQuery('#uncracked_by_creation').bind('click',function(){u(s[0],bycreation);return false});}}).error(function(e){m(e.responseJSON);});}g(1);</script><link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/Sites/codegolf/all.css?v=7509797c03ea"><div id="api_error"></div><div class="main"><h3>Uncracked submissions</h3><table> <tr> <th>Language</th> <th class="score">Score</th> <th>User</th> </tr> <tbody id="uncracked"></tbody></table><div>Sort by: <a href="#" id="uncracked_by_score">score</a> <a href="#" id="uncracked_by_creation">creation</a></div></div><div class="main"><h3>Safe submissions</h3><table> <tr> <th>Language</th> <th class="score">Score</th> <th>User</th> </tr> <tbody id="safe"></tbody></table></div>
Note
This challenge is finished. The final winner is feersum with his Seed answer. Congratulations! :).
You can still submit new cops, but be aware that they are no longer competing.
• @Andan That seems unfortunate. Say I write a golf with multiple clever tricks that improve on the obvious formula. If I post the obvious formula, anyone can find one improvement and win. Or, I have to tip my hand and give away all the improvements but one. Would you consider changing this, if it's not too late? Sorry for not thinking of this in this sandbox, I only noticed when trying the challenge in earnest. – xnor Aug 6 '16 at 11:07
• @xnor Hmm, that would cause a big problem with the scoring mechanism. You can then make an arbitirarily large submission and an almost impossible short one, and win the challenge. – Adnan Aug 6 '16 at 11:12
• @Adnan You could solve that by defining score = len(secret code)/min {len(public code), len(shortest code posted by robbers)}. – Anders Kaseorg Aug 6 '16 at 12:22
• @Adnan The context is xnor’s suggestion to make the score count if the robbers beat your public score but do not match your secret score. I’m proposing a way to make that work while avoiding the problem you’re concerned about. – Anders Kaseorg Aug 6 '16 at 12:43
• Yeah, finally another Cooooops and Rooooobbbbbers challenge. – insertusernamehere Aug 6 '16 at 20:41
## QBasic (QB64), 30 bytes, score = 28 / 30 = 0.9333 (cracked)
INPUT n:p=n MOD 2:?p*n+(n+p)/2
Computes A014682, a version of the Collatz function (offset 0).
This works on the QB64 emulator with autoformatting turned off. It should work on actual QBasic as well, but I don't have a copy to test it.
My 28-byte version used a bitwise operator and integer division:
INPUT n:?(1AND n)*n+(n+.5)\2
• Cracked – feersum Aug 19 '16 at 20:32
• So "integer division" is floating-point division followed by round to nearest? Funny :) – feersum Aug 19 '16 at 21:04
• @feersum Even curiouser, actually: it appears to be round to nearest followed by integer division. For example, 1.4\2 gives 0, but 1.6\2 gives 1. I can't confirm whether that's how it works in actual QBasic or if it's a QB64 quirk, but it's weird, in any case. ... Which just made me realize that I could have used 1 instead of .5, for 27 bytes. D'oh! – DLosc Aug 19 '16 at 21:49
## Acc!!, 526 bytes, score = 0.5627 (296/526) (cracked)
N
Count x while _%60-46 {
(_+_%60*5-288)*10+N
}
_/60
Count i while _/27^i {
_+27^i*(_/27^i*26-18)
}
_*3+93
Count i while _/27^i/27%3 {
_-i%2*2+1
Count j while _/3^(3*j+2-i%2)%3 {
_+3^(1+i%2)
Count k while _/3^(3*k+1+i%2)%3-1 {
_+3^(3*k+1+i%2)*26
}
}
}
Count i while _/27^i/3 {
_-_/27^i/3%27*27^i*3+_/3^(3*i+1+_%3)%3*3
}
_/3
Count i while _/100^i {
_+_/100^i*100^i*9
}
Count i while _/100^i/10 {
_+_/100^i/10%10
Count j while i+1-j {
_+(_%10-_/100^(j+1)%10)*(100^(j+1)-1)
}
}
_/100
Count j while _/100^j {
Write _/100^j%10+48
}
Computes A000204, Lucas numbers with offset 1.
A couple of notes. Due to Acc!!'s input limitations, the program takes input as a decimal number terminated with a period (.); for example:
> python acc.py Program.txt
5.
11
This program has exponential time complexity, so I wouldn't recommend running it with input greater than about 14 (takes 60 seconds on my laptop). However, given enough time, the algorithm will return the correct result for any positive integer n. Thus: a crack attempt that places any size limits on the input value is invalid.
Have fun!
• cracked (barely) – Dennis Aug 20 '16 at 17:59
## Python, 46 bytes, score = 0.97826 (45 / 46) [cracked]
f=lambda n,k=1:n and-~f(n-("01"in bin(k)),k+1)
Calculates A101082 (offset = 1), which are:
Numbers n such that binary representation contains bit strings "10" and "01" (possibly overlapping).
@Dennis cracked the submission as intended, which was to replace "01"in bin(k) with some bit twiddling, namely (k&-k)+k&k>0, to check that k's binary representation isn't of the form 111...111000...000.
• cracked – Dennis Aug 21 '16 at 7:56
## Acc!!, 512 bytes, score = 0.5625 (288 ÷ 512) (cracked)
Fourth try. Let's see how fast Dennis cracks this one. (Edit: 8 minutes, that's a record!)
N
Count x while _%60-46 {
(_+_%60*5-288)*10+N
}
_/30
Count i while _/27^i {
_+(_/27^i*26-18)*27^i
}
_*3+93
Count i while _/27^i/27%3 {
_-i%2*2+1
Count j while _/3^(3*j+2-i%2)%3 {
_+3+i%2*6
Count k while _/3^(3*k+1+i%2)%3-1 {
_+27^k*3^(i%2)*78
}
}
}
Count i while _/27^i/3 {
_-_/27^i/3%27*27^i*3+_/3^(3*i+1+_%3)%3*3
}
_/3
Count i while _/100^i {
_*10-_%100^i*9
}
Count i while _/100^i/10 {
_+_/100^i/10%10
Count j while i+2-j {
_+(_%10-_/100^j%10)*(100^j-1)
}
}
_/100
Count j while _/100^j {
Write _/100^j%10+48
}
Computes A002878, Lucas(2*n+1), offset = 0.
Due to Acc!!'s input limitations, the program takes input as a decimal number terminated with a period (.); for example:
> python acc.py Program.txt
3.
29
This program has exponential time complexity, so I wouldn't recommend running it with input greater than about 7. However, given enough time, the algorithm will return the correct result for any positive integer n. Thus: a crack attempt that places any size limits on the input value is invalid.
• cracked – Dennis Aug 26 '16 at 20:49
• @Dennis Hey, fastest yet! – DLosc Aug 26 '16 at 20:52
# J, 12 bytes, score = 0.9167 (11/12) (cracked)
(#++/)@I.@#:
Computes A230877.
• Cracked – feersum Sep 9 '16 at 19:38
# Woefully, (noncompeting, but you still get points for cracking it), 520/776= ~0.67 Cracked by Feersum.
Computes A000042 (would compute repunits, but that one has 0 as first member)
Offset 1, zero indexed (0 outputs 1, 1 outputs 11, 2 outputs 111, etc.)
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Try it online!
I like to think that my shorter solution was a pretty nice one.
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What I did was remove the push one command from the top, replace it at the bottom and at the end of the first command, which was free because I just had to replace some pipes, which then allowed me to shorten the push nine commands some more, because it didn't need to move that much anymore
• This TIO link is way too long o_o – TuxCrafting Sep 7 '16 at 8:17
• Cracked – feersum Sep 8 '16 at 2:08
# J, 18 bytes, score = 0.7222 (13/18) (cracked)
0{]1&(}.],+/)2 1"_
Computes the Lucas numbers, A000032.
• Cracked – feersum Sep 29 '16 at 0:25
# Sesos, 14 bytes, score = 0.6429 (9/14) (cracked)
0000000: aed40b b47bc2 8e01be 8e9ddb b107 ....{.........
Computes A130909.
Try it online!
• – Lynn Aug 6 '16 at 11:57
• You need to include the score in the header of your submission. – R. Kap Aug 6 '16 at 12:01
# Python 3.5, 38 bytes, Score = 0.86842 (33/38) (Cracked):
G=lambda n:n<1and 1or(2*n-1)**2*G(n-1)
Computes A001818.
Try It Online! (Ideone)
• Cracked – feersum Aug 6 '16 at 18:44
# 05AB1E, 10 bytes, score = 5 ÷ 10 = 0.5, cracked
This one isn't too hard actually :p. Code:
[NNÂʽ¾¹Q#
Computes the Nth non-palindromic number, which is A029742.
Try it online!
• Cracked. – Lynn Aug 7 '16 at 18:58
# JavaScript (ES6), 77 bytes, score = 0.9481 (73 / 77) [Cracked]
n=>eval("for(i=0;n;a||n--)[...s=a=++i+''].map(d=>a-=Math.pow(d,s.length));i")
Computes A005188, (offset = 1).
Didn't end up being super interesting but I thought I'd try and submit something.
Note: This is in ES6 so there is no ** operator. I just thought this would make it more cross-browser compatible and easier to test.
• Cracked – feersum Aug 8 '16 at 5:52
• @feersum Lol, I should have spent more time golfing it! Evidently this is possible in 72 bytes... – user81655 Aug 8 '16 at 6:07
Python (3.4.3), 77 bytes, score = 0.7272 (56/77) cracked
import math;lambda x: 1 if x==0 else (0 if ((math.sqrt(1+8*x)-1)/2)%1 else 1)
Computes A010054, offset = 0
• Cracked – feersum Aug 8 '16 at 18:28
# Coffeescript, 83 bytes, score = 79/83 = 0.952 [cracked!]
r=(n)->return if r<0 then 0 else Array(parseInt(n/9)+2).join ((n-1)%9+1).toString()
Computes A010785.
(Not so) Surprisingly, @DomHastings managed to shave 33 bytes off of my solution.
Wow, I suck at , don't I? Well, here's my other code:
r=(n)->return if r<0 then 0 else ((n-1)%9+1).toString().repeat(parseInt(n/9)+2)
Here's a less messy version of the code:
r=(n)->
if r<0
return 0
else
((n-1)%9+1).toString().repeat(parseInt(n/9)+2)
# ((n-1)%9+1).toString() is the repeating digit (as a string).
# parseInt(n/9)+2 is the times the digit is repeated.
• – Dom Hastings Aug 9 '16 at 11:42
# 05AB1E, 13 bytes, score = 0.769 (10 ÷ 13), cracked
This one isn't too hard either. Code:
µN•vÉ•vyK}g_½
Calculates A001742 (offset = 1).
• Cracked. Gonna keep working on that 10 byte solution for a while. – Emigna Aug 8 '16 at 14:18
## Actually, 28 bytes, Score = 0.39285714 (11/28) (cracked)
2√;;4*;u@D))u(*,;)@ⁿ)1-*ⁿ@-½
Computes A048696 (offset = 0). Actually uses CP437 for its encoding.
Try it online!
Dennis's solution is actually almost identical to mine:
19,;τ(+nX (Dennis)
19(;)τ+nX (Mine)
A Levenshtein distance of 3 is pretty impressive!
Try it online!
• cracked – Dennis Aug 14 '16 at 22:25
# Jelly, 22 bytes, score 0.2727 (6 / 22) [cracked]
‘ðḤ;+;c2\×P:+’×\$¥µÐ€‘S
This calculates sequence A116881. Try it online!
• Cracked – feersum Aug 19 '16 at 18:35
## Pip, 24 bytes, score = 22 / 24 = 0.9166 (cracked)
Y53T++i>ay.:k.A(yi)A(ya)
Computes A109648 (offset = 0). Try it online!
My 22-byte version:
T++v>alPB A(lJk|5v)l@a
• Cracked – feersum Aug 19 '16 at 22:21
# 05AB1E, 7 bytes, score = 0.857 (6 / 7) [cracked]
This one shouldn't be too hard if you think about it :p. Code:
L!zO¹!*
Computes A002627.
• Cracked – Emigna Aug 20 '16 at 20:40
## Acc!!, 523 bytes, score = 0.55067 (288/523) (cracked)
Second try, slightly different sequence.
N
Count x while _%60-46 {
(_+_%60*5-288)*10+N
}
_/60
Count i while _/27^i {
_+27^i*(_/27^i*26-18)
}
_*3+93
Count i while _/27^i/27%3 {
_-i%2*2+1
Count j while _/3^(3*j+2-i%2)%3 {
_+3^(1+i%2)
Count k while _/3^(3*k+1+i%2)%3-1 {
_+3^(3*k+1+i%2)*26
}
}
}
Count i while _/27^i/3 {
_-_/27^i/3%27*27^i*3+_/3^(3*i+1+_%3)%3*3
}
_/3
Count i while _/100^i {
_*10-_%100^i*9
}
Count i while _/100^i/10 {
_+_/100^i/10%10
Count j while i+1-j {
_+(_%10-_/100^(j+1)%10)*(100^(j+1)-1)
}
}
_/100
Count j while _/100^j {
Write _/100^j%10+48
}
Computes A000032, Lucas numbers with offset 0.
Due to Acc!!'s input limitations, the program takes input as a decimal number terminated with a period (.); for example:
> python acc.py Program.txt
5.
11
This program has exponential time complexity, so I wouldn't recommend running it with input greater than about 14 (takes 60 seconds on my laptop). However, given enough time, the algorithm will return the correct result for any positive integer n. Thus: a crack attempt that places any size limits on the input value is invalid.
• cracked – Dennis Aug 21 '16 at 4:14
## Acc!!, 522 bytes, score = 0.5555 (290 ÷ 522) (cracked)
Third try. Thanks to Dennis for the golfing "help" with the first two. ;^)
N
Count x while _%60-46 {
(_+_%60*5-288)*10+N
}
_/60*2
Count i while _/27^i {
_+(_/27^i*26-18)*27^i
}
_*3+93
Count i while _/27^i/27%3 {
_-i%2*2+1
Count j while _/3^(3*j+2-i%2)%3 {
_+3+i%2*6
Count k while _/3^(3*k+1+i%2)%3-1 {
_+27^k*3^(i%2)*78
}
}
}
Count i while _/27^i/3 {
_-_/27^i/3%27*27^i*3+_/3^(3*i+1+_%3)%3*3
}
_/3
Count i while _/100^i {
_*10-_%100^i*9
}
Count i while _/100^i/10 {
_+_/100^i/10%10
Count j while i+1-j {
_+(_%10-_/100^(j+1)%10)*(100^(j+1)-1)
}
}
_/100
Count j while _/100^j {
Write _/100^j%10+48
}
Computes A005248, Lucas(2*n), offset = 0.
Due to Acc!!'s input limitations, the program takes input as a decimal number terminated with a period (.); for example:
> python acc.py Program.txt
3.
18
This program has exponential time complexity, so I wouldn't recommend running it with input greater than about 7. However, given enough time, the algorithm will return the correct result for any positive integer n. Thus: a crack attempt that places any size limits on the input value is invalid.
• cracked – Dennis Aug 21 '16 at 5:38
# Excel, 16 bytes, score = 0.75, [cracked by Dennis♦]
=FACTDOUBLE(2*n)
Computes A000165: double factorial of even numbers, (offset = 0).
• Cracked? – Dennis Aug 21 '16 at 8:09
• This answer doesn't have the correct form -- it is not a program or a function. – feersum Aug 21 '16 at 14:22
• @feersum By the definition here, it is a program – Anastasiya-Romanova 秀 Aug 21 '16 at 14:30
• See here. Input by inserting the number into the source code isn't an accepted input method. – feersum Aug 21 '16 at 14:35
• @feersum Name the cell input as n. See this – Anastasiya-Romanova 秀 Aug 21 '16 at 15:00
# Python, 39 bytes, 26/39=2/3=0.666 cont. points, cracked
s=lambda x:x+s(x-1)if x==1else x+s(x-1)
won't last long, but lets see just how long. Just doing the robbers a favour I guess (also because I don't know eso golf langs ;_;)
umm, I accidentally bad code but someone cracked my lower score so...
computes A000217
• How does this terminate if the then clause and the end clause are the same? – Leaky Nun Aug 6 '16 at 12:02
• Which version of Python is this? – Leaky Nun Aug 6 '16 at 12:04
• – Leaky Nun Aug 6 '16 at 12:05
• You need to include the score in the header :3. – Adnan Aug 6 '16 at 12:07
• also o sh*t I did the wrong code :( – Destructible Lemon Aug 6 '16 at 12:15
## Python, 69 bytes, score = 0.97 (67÷69), cracked
f=lambda n:reduce(lambda x,y:x*y,range(1,n+1),1)
lambda n:f(n*2)/f(n)
Computes A001813
• cracked – Dennis Aug 9 '16 at 19:28
# 05AB1E - 1 byte - A000027
Code: I
# 05AB1E - 0 bytes - A000027
Code:
Explanation:
I means that it pushes the input to the stack.
means that nothing is changed to the stack, but the input was already added to the stack by default, so it prints out the input.
• Please note this challenge has been inactive for 2 years. – u_ndefined Oct 14 '18 at 11:22
• Oh I thought that there was a proposal to revive old challenges – MilkyWay90 Oct 14 '18 at 13:52
|
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|
https://www.jobilize.com/physics-ap/course/17-5-sound-interference-and-resonance-standing-waves-in-air-by-opensta?qcr=www.quizover.com&page=4
|
# 17.5 Sound interference and resonance: standing waves in air columns (Page 5/11)
Page 5 / 11
We have emphasized sound applications in our discussions of resonance and standing waves, but these ideas apply to any system that has wave characteristics. Vibrating strings, for example, are actually resonating and have fundamentals and overtones similar to those for air columns. More subtle are the resonances in atoms due to the wave character of their electrons. Their orbitals can be viewed as standing waves, which have a fundamental (ground state) and overtones (excited states). It is fascinating that wave characteristics apply to such a wide range of physical systems.
Describe how noise-canceling headphones differ from standard headphones used to block outside sounds.
Regular headphones only block sound waves with a physical barrier. Noise-canceling headphones use destructive interference to reduce the loudness of outside sounds.
How is it possible to use a standing wave's node and antinode to determine the length of a closed-end tube?
When the tube resonates at its natural frequency, the wave's node is located at the closed end of the tube, and the antinode is located at the open end. The length of the tube is equal to one-fourth of the wavelength of this wave. Thus, if we know the wavelength of the wave, we can determine the length of the tube.
## Phet explorations: sound
This simulation lets you see sound waves. Adjust the frequency or volume and you can see and hear how the wave changes. Move the listener around and hear what she hears.
## Section summary
• Sound interference and resonance have the same properties as defined for all waves.
• In air columns, the lowest-frequency resonance is called the fundamental, whereas all higher resonant frequencies are called overtones. Collectively, they are called harmonics.
• The resonant frequencies of a tube closed at one end are:
${f}_{1}$ is the fundamental and $L$ is the length of the tube.
• The resonant frequencies of a tube open at both ends are:
## Conceptual questions
How does an unamplified guitar produce sounds so much more intense than those of a plucked string held taut by a simple stick?
You are given two wind instruments of identical length. One is open at both ends, whereas the other is closed at one end. Which is able to produce the lowest frequency?
What is the difference between an overtone and a harmonic? Are all harmonics overtones? Are all overtones harmonics?
## Problems&Exercises
A “showy” custom-built car has two brass horns that are supposed to produce the same frequency but actually emit 263.8 and 264.5 Hz. What beat frequency is produced?
0.7 Hz
What beat frequencies will be present: (a) If the musical notes A and C are played together (frequencies of 220 and 264 Hz)? (b) If D and F are played together (frequencies of 297 and 352 Hz)? (c) If all four are played together?
What beat frequencies result if a piano hammer hits three strings that emit frequencies of 127.8, 128.1, and 128.3 Hz?
0.3 Hz, 0.2 Hz, 0.5 Hz
Calculate the work done by an 85.0-kg man who pushes a crate 4.00 m up along a ramp that makes an angle of 20.0º20.0º with the horizontal. (See [link] .) He exerts a force of 500 N on the crate parallel to the ramp and moves at a constant speed. Be certain to include the work he does on the crate an
What is thermal heat all about
why uniform circular motion is called a periodic motion?.
when a train start from A & it returns at same station A . what is its acceleration?
what is distance of A to B of the stations and what is the time taken to reach B from A
BELLO
the information provided is not enough
aliyu
Hmmmm maybe the question is logical
yusuf
where are the parameters for calculation
HENRY
there is enough information to calculate an AVERAGE acceleration
Kwok
mistake, there is enough information to calculate an average velocity
Kwok
~\
Abel
what is the unit of momentum
Abel
wha are the types of radioactivity ?
what are the types of radioactivity
Worku
what is static friction
It is the opposite of kinetic friction
Mark
static fiction is friction between two surfaces in contact an none of sliding over on another, while Kinetic friction is friction between sliding surfaces in contact.
MINDERIUM
I don't get it,if it's static then there will be no friction.
author
It means that static friction is that friction that most be overcome before a body can move
kingsley
static friction is a force that keeps an object from moving, and it's the opposite of kinetic friction.
author
It is a force a body must overcome in order for the body to move.
Eboh
If a particle accelerator explodes what happens
Eboh
why we see the edge effect in case of the field lines of capacitor?
Arnab
what is wave
what is force
Muhammed
force is something which is responsible for the object to change its position
MINDERIUM
more technically it is the product of mass of an object and Acceleration produced in it
MINDERIUM
wave is disturbance in any medium
iqra
energy is distributed in any medium through particles of medium.
iqra
If a particle accelerator explodes what happens
we have to first figure out .... wats a particle accelerator first
Teh
What is surface tension
The resistive force of surface.
iqra
Who can tutor me on simple harmonic motion
on both a string and peldulum?
Anya
spring*
Anya
Yea
yusuf
Do you have a chit-chat contact
yusuf
I dont have social media but i do have an email?
Anya
Which is
yusuf
Where are you chatting from
yusuf
I don't understand the basics of this group
Jimmy
teach him SHM init
Anya
Simple harmonic motion
yusuf
how.an.equipotential.line is two dimension and equipotential surface is three dimension ?
definition of mass of conversion
Force equals mass time acceleration. Weight is a force and it can replace force in the equation. The acceleration would be gravity, which is an acceleration. To change from weight to mass divide by gravity (9.8 m/s^2).
Marisa
how many subject is in physics
the write question should be " How many Topics are in O- Level Physics, or other branches of physics.
effiom
how many topic are in physics
Praise
Praise what level are you
yusuf
If u are doing a levels in your first year you do AS topics therefore you do 5 big topic i.e particles radiation, waves and optics, mechanics,materials, electricity. After that you do A level topics like Specific Harmonic motion circular motion astrophysics depends really
Anya
Yeah basics of physics prin8
yusuf
Heat nd Co for a level
yusuf
yh I need someone to explain something im tryna solve . I'll send the question if u down for it
a ripple tank experiment a vibrating plane is used to generate wrinkles in the water .if the distance between two successive point is 3.5cm and the wave travel a distance of 31.5cm find the frequency of the vibration
Tamdy
hallow
Boniface
Boniface
the range of objects and phenomena studied in physics is
Boniface
|
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|
https://repo.scoap3.org/search?f=author&p=Zapata%2C%20Jos%C3%A9%20A.&ln=en
|
SCOAP3 Repository 1 records found Search took 0.24 seconds.
1 Gauge from Holography and Holographic Gravitational Observables / Zapata, José A. In a spacetime divided into two regions ${U}_{\mathrm{1}}$ and ${U}_{\mathrm{2}}$ by a hypersurface $\mathrm{\Sigma }$ , a perturbation of the field in ${U}_{\mathrm{1}}$ is coupled to perturbations in ${U}_{\mathrm{2}}$ by means of the holographic imprint that it leaves on $\mathrm{\Sigma }$ . [...] Published in Advances in High Energy Physics 2019 (2019) 9781620 10.1155/2019/9781620 arXiv:1704.07959 Fulltext: PDF XML PDF (PDFA);
Interested in being notified about new results for this query?
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https://en.wikipedia.org/wiki/Procedural_texture
|
Procedural texture
A procedurally generated floor grate texture
A procedural texture is a computer-generated image created using an algorithm intended to create a realistic surface or volumetric representation of natural elements such as wood, marble, granite, metal, stone, and others, for use in texture mapping.
Usually, the natural look of the rendered result is achieved by the usage of fractal noise and turbulence functions. These functions are used as a numerical representation of the “randomness” found in nature.
Solid texturing
Solid texturing is a process where the texture generating function is evaluated over ${\displaystyle R^{3}}$ at each visible surface point of the model. Traditionally these functions use Simplex noise or Perlin noise as their basis function, but some simple functions may use more trivial methods such as the sum of sinusoidal functions for instance. Solid textures are an alternative to the traditional 2D texture images which are applied to the surfaces of a model. It is a difficult and tedious task to get multiple 2D textures to form a consistent visual appearance on a model without it looking obviously tiled. Solid textures were created to specifically solve this problem.
Instead of editing images to fit a model, a function is used to evaluate the colour of the point being textured. Points are evaluated based on their 3D position, not their 2D surface position. Consequently, solid textures are unaffected by distortions of the surface parameter space, such as you might see near the poles of a sphere. Also, continuity between the surface parameterization of adjacent patches isn’t a concern either. Solid textures will remain consistent and have features of constant size regardless of distortions in the surface coordinate systems. [1]
Cellular texturing
Cellular texturing differs from the majority of other procedural texture generating techniques as it does not depend on noise functions as its basis, although it is often used to complement the technique. Cellular textures are based on feature points which are scattered over a three-dimensional space. These points are then used to split up the space into small, randomly tiled regions called cells. These cells often look like “lizard scales,” “pebbles,” or “flagstones”. Even though these regions are discrete, the cellular basis function itself is continuous and can be evaluated anywhere in space. [2]
Genetic textures
Genetic texture generation is highly experimental approach for generating textures. It is a highly automated process that uses a human to completely moderate the eventual outcome. The flow of control usually has a computer generate a set of texture candidates. From these, a user picks a selection. The computer then generates another set of textures by mutating and crossing over elements of the user selected textures.[3] For more information on exactly how this mutation and cross over generation method is achieved, see Genetic algorithm. The process continues until a suitable texture for the user is generated. This isn't a commonly used method of generating textures as it’s very difficult to control and direct the eventual outcome. Because of this, it is typically used for experimentation or abstract textures only.
Self-organizing textures
Starting from a simple white noise, self-organization processes lead to structured patterns - still with a part of randomness. Reaction-diffusion systems are a good example to generate such kind of textures.
Example of a procedural marble texture
(Taken from The Renderman Companion Book, by Steve Upstill)
``` /* Copyrighted Pixar 1988 */
/* From the RenderMan Companion p. 355 */
/* Listing 16.19 Blue marble surface shader*/
/*
* blue_marble(): a marble stone texture in shades of blue
* surface
*/
blue_marble(
float Ks = .4,
Kd = .6,
Ka = .1,
roughness = .1,
txtscale = 1;
color specularcolor = 1)
{
point PP; /* scaled point in shader space */
float csp; /* color spline parameter */
point Nf; /* forward-facing normal */
point V; /* for specular() */
float pixelsize, twice, scale, weight, turbulence;
/* Obtain a forward-facing normal for lighting calculations. */
Nf = faceforward( normalize(N), I);
V = normalize(-I);
/*
* Compute "turbulence" a la [PERLIN85]. Turbulence is a sum of
* "noise" components with a "fractal" 1/f power spectrum. It gives the
* visual impression of turbulent fluid flow (for example, as in the
* formation of blue_marble from molten color splines!). Use the
* surface element area in texture space to control the number of
* noise components so that the frequency content is appropriate
* to the scale. This prevents aliasing of the texture.
*/
PP = transform("shader", P) * txtscale;
pixelsize = sqrt(area(PP));
twice = 2 * pixelsize;
turbulence = 0;
for (scale = 1; scale > twice; scale /= 2)
turbulence += scale * noise(PP/scale);
if (scale > pixelsize) {
weight = (scale / pixelsize) - 1;
weight = clamp(weight, 0, 1);
turbulence += weight * scale * noise(PP/scale);
}
/*
* Magnify the upper part of the turbulence range 0.75:1
* to fill the range 0:1 and use it as the parameter of
* a color spline through various shades of blue.
*/
csp = clamp(4 * turbulence - 3, 0, 1);
Ci = color spline(csp,
color (0.25, 0.25, 0.35), /* pale blue */
color (0.25, 0.25, 0.35), /* pale blue */
color (0.20, 0.20, 0.30), /* medium blue */
color (0.20, 0.20, 0.30), /* medium blue */
color (0.20, 0.20, 0.30), /* medium blue */
color (0.25, 0.25, 0.35), /* pale blue */
color (0.25, 0.25, 0.35), /* pale blue */
color (0.15, 0.15, 0.26), /* medium dark blue */
color (0.15, 0.15, 0.26), /* medium dark blue */
color (0.10, 0.10, 0.20), /* dark blue */
color (0.10, 0.10, 0.20), /* dark blue */
color (0.25, 0.25, 0.35), /* pale blue */
color (0.10, 0.10, 0.20) /* dark blue */
);
/* Multiply this color by the diffusely reflected light. */
Ci *= Ka*ambient() + Kd*diffuse(Nf);
Oi = Os;
Ci = Ci * Oi;
/* Add in specular highlights. */
Ci += specularcolor * Ks * specular(Nf,V,roughness);
}
```
|
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|
https://www.intechopen.com/chapters/45632
|
Open access peer-reviewed chapter
# Production of Biofuels from Cellulose of Woody Biomass
Written By
Pedram Fatehi
Submitted: November 3rd, 2011 Reviewed: June 17th, 2012 Published: August 29th, 2013
DOI: 10.5772/50740
From the Edited Volume
## Cellulose
Edited by Theo van de Ven and John Kadla
Chapter metrics overview
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## 1. Introduction
Today, fossil resources supply approximately 86% of energy and 96% of organic chemicals used in the world [1]. The continuous depletion of petroleum fuel is one of the prime concerns these days. Other concerns associated with the large-scale utilization of fossil fuels are availability, global warming and uneven geographic distribution [2,3]. Also, the global population is expected to increase by approximately 3 billion people by 2050, which substantially increases the need for fuels. One estimate indicated that the world energy consumption would increase by 35% over the next 20 years in order to meet the growing demand of industrialized countries and the rapid development of emerging economies [2]. As the fossil fuels are depleting in the coming years, new technologies should be developed in order to produce fuels from renewable biomass resources [4].
Currently, biomass accounts for 9.8% of the world’s primary energy use annually, among which 30% is used in modern forms (e.g. liquid biofuel and steam), and 70% is used traditionally (combustion for domestic heating with the energy density of 15-20 MJ/kg) [2,4,5]. Biofuel is a type of fuel whose energy is derived from biomass. It includes solid biofuels such as wood pellets, wood cube and wood puck; liquid biofuels such as ethanol and butanol; and gaseous biofuel such as hydrogen. The world liquid biofuel production would increase from 1.9 million of barrels per day in 2010 to 5.9 million barrel per day in 2030 [2]. In the United States, expectation for the production of biofuels is 136 billion litter mandated by 2022, of which 61 million liter are made from cellulosic materials [6].
As described earlier, biomass has directly been used for producing heat and electricity. The power generation engines were designed so that they directly used biomass as energy source during World War II. However, this direct utilization has several major problems: if used as biofuel, the uneven geographical distribution of biomass necessitate its transportation, the bulky nature of biomass (low heat value) leads to costly and complicated transportation systems; engines utilizing biomass usually possess a poor efficiency and high environmental impact (e.g. CO2 emission). However, according to the first law of thermodynamics, any biological or chemical conversion of biomass to biofuel will consume energy, thus a part of the energy stored in biomass will be lost during the conversion and the biofuel (product) will ultimately have a lower energy than will biomass (raw material). There are several advantages for the conversion of biomass to biofuel that outweighs this deficiency: there is a large demand for liquid fuel (e.g. ethanol) in the transportation sector; the biofuel production process is more environmentally friendly (i.e. less CO2 emission); the digested materials from biorefinery can be readily used as an excellent and sustainable fertilizer for cultivation and crops (a true recyclable process); the energy density (MJ/kg) of biofuel will be higher than that of biomass, and the common problem of combustion, e.g. fly ash disposal and super heater corrosion, can be eliminated via biofuel production [2,7,8].
One of the challenges of biofuel production is the difficulties in increasing the bulk density of the resource, while preserving its energy content [9]. The future biofuel should 1) have a high energy density on a mass; 2) be produced at yields near the stoichiometric maximum from a given biomass feed; 3) be compatible with existing fuel distribution infrastructures; 4) have a minimum impact on environment; and 5) not affect the global food supplies [9-11].
The first generation biofuels are presently produced from sugars, starches and vegetable oils, but these products have several issues: 1) their availability is limited by soil fertility and per-hectare yield; and 2) their contribution to savings of CO2 emissions and fossil energy consumption are limited by high energy input for their cultivations and conversions [12-14]. However, lignocellulosic biomass seems to be more attractive because 1) it is the most widespread renewable source available on earth (overall chemical energy stored in biomass by plants is approximately 6-7 times of total human energy consumption annually [15]); 2) it is locally available in many countries; and more importantly 3) it does not compete with food or food industries [12]. However, the conversion of woody biomass to fermentable sugars is more difficult than that of agro-based biomass because of the presence of more hemicelluloses (not easily fermentable) and lignin as well as more condensed and crystallized structure of cellulose in woody biomass [9].
Current technologies to produce biofuel from cellulosic materials involve gasification, pyrolysis/liquefaction and hydrolysis of biomass. This book chapter excludes 1) the studies on the gasification and pyrolysis/liquefaction of biomass (as an intact raw material) for biofuel production; and 2) the studies on the production of fuel additives, e.g. levulinic acid and furfural [16] and the studies on the production of biodiesel [17-22]. Instead, recent advancements and challenges associated with the production of ethanol, butanol, hydrogen and new furan-based biofuel from cellulosic biomass will be discussed.
In order to produce biofuel from cellulose of biomass, the lignocellulosic biomass should be first dissembled to facilitate the isolation of cellulose from other constituents, i.e. lignin and hemicelluloses. Subsequently, cellulose macromolecules should be depolymerized, as depolymerization significantly improves the chemical and biological conversions of cellulose to biofuel. Then, the depolymerized cellulose, i.e. glucose, should be converted to biofuel via biological treatments, and finally the biofuel should be purified. Additionally, biomass should be deoxygenated as the presence of oxygen reduces the heat content of molecules and creates high polarity, which impairs its blending with existing fossil fuels [12].
## 2. Pretreatment of biomass
The complex structure of lignocellulosic biomass makes its utilization in biofuel production difficult. Lignocellulosic raw materials are generally composed of 40-50% cellulose, 25-35% hemicelluloses and 15-20% lignin [8]. A pretreatment stage is necessary to dissociate the plant cell wall in order to improve the accessibility of chemicals and/or microorganisms to cellulose for possible conversions [23]. The pretreatment processes target the removal of lignin, which improves the digestibility of cellulose in the following hydrolysis process [24]. Table 1 lists various pretreatment processes of woody biomass conducted in the past in order to improve the performance of fermentation processes in producing biofuels.
Pretreatment type Example Physical pretreatment Ball milling, Irradiation Physicochemical pretreatment Steam explosion, hot water pretreatment Chemical pretreatment Acid, alkali, solvent Biological Fungi Enzyme Cellulase
### Table 1.
Various pretreatment processes of lignocellulosic feedstock [14]
Physical pretreatment consists of mechanical disruption of lignocelluloses, which is an environmentally friendly process. This process increases the surface area of biomass and decreases the crystallinity of cellulose, but it does not cause an expensive mass loss [25]. Irradiation using gamma rays, electron rays and microwaves are other physical methods to beak the structure of lignocelluloses. Microwave irradiation has been applied in many fields including food drying chemical synthesis and extraction [14].
Physicochemical pretreatment is another approach to separate the lignocelluloses of woody materials. Hydrothermal treatment, such as hot water pretreatment and steam explosion, is a suitable method particularly prior to enzyme hydrolysis. Hot water pretreatment process is conducted under pressure at an elevated temperature of 230-240 °C for 15 min to maintain water in liquid form, which produces less inhibitory compounds (e.g. furfural) compared to steam explosion method [26,27]. However, the viscosity of the spent liquor produced in this method is rather high, which makes its handling process challenging. The steam explosion is practically applied in industry via steaming biomass at an elevated temperature, e.g. 170 °C [28-30]. To limit the production of inhibitors, process conditions should be precisely adjusted. Steam explosion has different subcategories, such as ammonia fiber explosion and acid-explosion, in which acid or ammonia is also added to the system during the steaming process.
The chemical pretreatment of cellulosic biomass includes oxidizing hydrolysis, acid or alkaline hydrolysis and solvent extraction. In this context, lime treatment (e.g. treatment of woody biomass at 180 °C with lime solutions) has been considered as an effective chemical pretreatment method, because of its low cost and wide use in agro- and wood-based processes [4,27,31-34]. Pretreatment with dilute acid at intermediate temperatures (e.g. 160 °C) is usually considered the most cost-effective method to loosen the cell wall matrix via degrading the hemicelluloses of biomass [27,35].
Biological pretreatment, such as fungal, is milder in its operational conditions than physical or chemical pretreatment. The oxidative biodegradation of lignin by white-rot fungi has been widely studied in the past [36]. The main advantages of biological pretreatment are low energy input, no chemical requirement, mild environmental conditions and environmentally friendly working manner [25]. However, the biological pretreatment processes usually need a long retention time and have a low yield. They are also sensitive to the process conditions such as temperature and pH. Enzymatic pretreatment of biomass has been comprehensively studied in the past and will be discussed in a separate section.
## 3. Hydrolysis
Generally, microorganisms have poor cellulose/biomass digestibility and a limited efficiency in producing biofuels. Hydrolysis has been commonly applied in industrial scales to improve the efficiency of microorganisms in producing biofuels prior to fermentation, which relies on the decomposition of polysaccharides to monosaccharides [37].
### 3.1. Enzyme hydrolysis
In this process, enzyme is used for decomposing polysaccharides into monosaccharides. Microorganisms that usually produce enzyme are fungal species, such as hypocerea jecornia, trichoderma reesei, and bacteria species, such as clostridium thermocellum, cellulomonas flavigena. Three main enzymes hydrolyzing cellulose to glucose are cellulase, 1-4- β-D-endoglucanase and 1-4- β-D-cellobiohydrolase[38]. Process parameters, e.g. pH, temperature, time, significantly affect the performance of enzyme hydrolysis. Furthermore, porosity and crystallinity and the lignin content of biomass seem to significantly influence the efficiency of this process [25].
Equation 1 describes the enzymatic hydrolysis model of cellulose to glucose [39]:
X=1-Ke+e0KeKae0t+1+e0bE1
where e0 is the initial enzyme concentration (g/l), X is conversion efficiency (<1), t is the reaction time (h), ka is the enzyme deactivation constant (g/l.h), b=kekak1 is the fitted constant (dimensionless), ke is the adsorption equilibrium constant (g/l), and k1 is the rate constant of sugar formation (1/h). When e0, X converges to a constant at constant time according to equation 2:
X=1-1KeKat+1bE2
and when t, X converges to a maximum conversion of 1.
Figure 1 shows the results of one study on the enzyme hydrolysis of pre-steamed corn Stover at 50 °C and pH 4.8, the conversion of celluloses to reducing sugar was 60% after 48h. Fitting the experimental data of Figure 1 into equation 1 resulted in ke, ka, k1, and b of 0.9975 (g/l), 0.9837 (l/g.h), 0.2843 (1/h), and 0.2897, respectively [39].
Enzymatic hydrolysis has several advantages compared with acid hydrolysis such as a lower equipment cost and higher glucose yield without sugar degrading products or by-products [24].
### 3.2. Acid hydrolysis
This method has been extensively applied to convert oligomeric sugars to monomeric sugars in the past [40-43]. It has a short process time (i.e. less than 1 h) and produces a higher sugar yield (>85%), but operates at a relatively high temperature, e.g. >120 °C (compared to enzyme hydrolysis). However, acid hydrolysis may result in the production of undesirable by-products that should be eliminated prior to fermentation processes. These detoxification processes are generally costly and complicated [25,40-42].
## 4. Detoxification process
Natural occurring and process-induced compounds may retard the fermentation processes for producing biofuels, which complicates the fermentation process [42-46]. These inhibitors are phenols, acetic acid, furfural, metal ions and lignosulfonates, and can chemically or biologically be removed from hydrolysates prior to fermentation processes.
Boiling and overliming have been extensively used in different studies to reduce the concentration of the inhibitors [44-46]. Boiling was proposed to reduce the concentration of volatile components, e.g. furfural, and overliming was proposed to create some insoluble inorganic salts that adsorb inhibitors [47]. Alternatively, the inhibitors can be removed by employing the concept of adsorption and flocculation phenomena. In this regard, commercial adsorbents, e.g. activated carbons, fillers, e.g. calcium carbonate or lime, or ion exchange resins may be suitable choices. The adsorption/flocculation processes could effectively remove these inhibitors and research in improving the performance of this process is on-going [28,30,48-50].
Alternatively, the inhibitors can be removed from hydrolysates via biological treatments. For example, a mutant yeast, S. cerevisiaeYGSCD 308.3, was applied to reduce the acetic acid content of the ammonia-based hardwood hydrolysate in one study [51]. This yeast grows on acetic acid, but not on xylose, glucose, mannose and fructose. This detoxification process resulted in an ethanol production (fermentation was conducted at a temperature of 30 °C, and 300 rpm for 24 h) with a 73% yield of that of the maximum theoretical value in a laboratory scale. However, the presence of acetic acid did not allow ethanol production in the control sample of this study [51].
## 5. Ethanol production
As of January 2008, 136 ethanol plants in the US produced 7.5 billion gallons of ethanol annually, and this number is expected to increase by 13.3 billion gallons/year via constructing additional 62 plants [4]. The current biofuel market is largely dominated by ethanol (90% of the world biofuel production) [2]. However, most of ethanol produced today comes from starch (as in maize grains) or sucrose (from sugarcane), i.e. first generation biofuel. Lignocellulosic biomass, on the other hand, represents more abundant feedstock for ethanol production, i.e. the second generation biofuel [4]. However, the cost of producing lignocellulosic ethanol could be almost double of that of corn-derived ethanol [2]. In this context, the US department of Energy (DOE) has committed over $1 billion dollars toward a realization of a 2012 goal of making lignocellulosic ethanol at a competitive cost of$1.33 per gallon [52].
The production of ethanol from biomass has been criticized in the past since a large amount of CO2 is produced (released) as the by-product of this fermentation process. However, one study showed that, if softwood (unspecified species and fermentation conditions) biomass were considered as raw material, and ethanol were produced from cellulose and hemicelluloses and FT-diesel from lignin, this integrated process could lead to 54% of mass conversion efficiency, 67% of carbon conservation efficiency, but more interestingly, 88% of energy conversion efficiency [12]. In other words, the majority of mass, but just 12% of energy, would be lost in ethanol production process. Consequently, ethanol production process would definitely improve the energy density of biomass, which is a critical factor of biofuel. This analysis depicted that it was extremely crucial to widen the assessments beyond the sole mass balance to obtain a complete understanding of biofuel production [12].
### 5.1. Process alternatives
The biological processes of ethanol production usually involve hydrolysis, which breaks cellulose to glucose, and fermentation to convert glucose to ethanol. Ethanol can be produced via separate hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF). The SHF facilitates the operation of hydrolysis and fermentation processes under separate optimized conditions. Previous studies on pre-steamed agro-based raw materials (corn Stover) revealed that the yield (ethanol produced per unit mass of dried feedstock g/g) of SHF was higher than that of SSF [53]. Also, SHF has a faster hydrolysis rate than does SSF under optimized conditions [11,39]. In SSF process, cellulose is hydrolyzed to glucose by cellulase, while yeast spontaneously ferments glucose to ethanol [54]. The SSF usually has a higher productivity (ethanol produced per unit mass of dried feedstock per unit time, g/g.h) than does SHF, since SSF has a shorter operating time [39]. Other advantages of SSF over SHF include less inhibition of enzymes and a longer time of enzymatic hydrolysis. Usually, fermentation temperature and the presence of ethanol are not at optimized conditions for cellulase activities in the SSF process, which leads to poor enzyme performance. To overcome this difficulty, several approaches were followed in the past, which are demonstrated as follows:
1. Enzyme immobilization onto a solid support was proposed to improve the enzyme activity at non-optimal conditions (e.g. SSF). In one study, dissolved cellulase (500 µl, in 10 mM acetate buffer, pH 4.8 with 0.01 % (w/v) sodium azide) was immobilized on Aerosol OX-50 silica (40 nm average diameter particle, 1.4 m2 surface area), and the SSF was carried out using this coated silica [54]. The results showed that the ethanol yields of the SSF process containing immobilized enzyme were 2.3 and 2.1 times higher than that of the SSF process containing enzyme in solutions at pH 4.8 and 5.3, respectively. The higher ethanol yield of the immobilized enzyme process was likely due to higher glucose yields as a result of increased enzymatic stability at the non-optimal enzyme conditions required for the SSF [54]. However, this process results in a higher ethanol yield under the optimum conditions of fermentation rather than that of enzyme hydrolysis. This is because 1) the optimum conditions for the immobilized enzyme reaction may not coincide with those for the enzyme in solutions; 2) although the same mass of enzyme can be used in the solution and immobilized systems, it does not mean that the same amount of enzyme is available to participate in the hydrolysis reactions; and 3) enzyme immobilization results in a random orientation of adsorbed enzyme on the silica substrates, and this leads to some inactive enzyme due to buried or inaccessible active sites [54].
2. Semi-simultaneous saccharification and fermentation (SSSF) is another approach to produce ethanol. In this method, the hydrolysis process is applied under optimized conditions, which breaks down cellulose to glucose, and subsequently fermentation is conducted on the product of hydrolysis without removing the hydrolystate. In other words, it is an operating mode between the SHF and SSF, thus it has the advantages of both SHF and SSF (a higher productivity and yield). In one study on microcrystalline cellulose (Avicel PH101), three alternative processes were carried out to produce ethanol: 24h hydrolysis+48h SSF (called SSSF), 72 h SSF, and 24 h hydrolysis+48h fermentation (SHF) [39]. The hydrolysis process was conducted under the conditions of 50 °C, pH 4.8 and 2 g Novozymes enzyme, while the fermentation was performed under the conditions of 36 °C, pH 4.8 and 300 rpm using S. cereviasiae. The results showed that the optimal ethanol productivity for SSSF, SSF and SHF were 0.222, 0.194, and 0.176 g/l.h, respectively. The corresponding maximum ethanol concentration was 16, 14 and 12.6 g/l with equivalent theoretical ethanol yields of 70.5%, 61.8%, and 56.1%, respectively [39].
### 5.2. Theory
The theoretical ethanol yield (Y) can be calculated using equation 3 [39]:
Y=0.9E0.511C0100%E3
where E is the final ethanol concentration (g/l) and C0 is the initial cellulose concentration (g/l). Also, the fermentation efficiency (ef), from sugar to ethanol, can be determined using equation 4:
ef=E0.511Gh100%E4
where Gh is the glucose concentration after hydrolysis (g/l). When glucan in cellulose is completely converted into glucose (C0=0.9 Gh). The theoretical yield of SSF yield is equal to fermentation efficiency [39].
### 5.3. Microorganism for ethanol production
Ethanol production via fermentation has been the subject of several research activities. In this regard, many yeasts and bacteria have been introduced or modified and their ethanol production efficiencies have been assessed.
#### 5.3.1. Bacteria
Escherichia colican consume hexoses and pentoses for ethanol production. However, E. coliis less rebust against several factors including pH, salt concentration and temperature. It also exhibits a low ethanol (<35 g/l) and butanol tolerance (< 20g/l) [51]. Z. mobilishas also been applied in ethanol production, has a tolerance of up to 120 g/l ethanol, and its ethanol production yield approaches 97% of the maximum theoretical value under optimized conditions. However, it can only ferment glucose, fructose and sucrose (hexoses), and it has a low tolerance to acetic acid [55,56]. Clostridiahave also been applied in ethanol production under optimized temperature of 35-37 °C at a pH range of 6 and 9, which can ferment hexoses and pentoses [57]. Corynebacterium glutamicumhas also been applied for ethanol production, but it cannot ferment pentoses, unlike E. coli. [58].
#### 5.3.2. Yeast
Hexoses can effectively be converted to ethanol with a high yield (0.4-0.51 g ethanol/ g glucose) and a high productivity (up to 1 g/l.h) by Saccharomyces cerevisiaeor re-combinant S. cerevisiae[53,55]. S. cerevisiaeis the best known microorganism used for fermenting glucose to ethanol, but it cannot ferment pentoses. In this respect, the fermentation rate of xylose is 3-12 times lower than that of glucose by S. cerevisiae[45]. Kluyveromycesis another thermotolorant species with up to 98% of the maximum theoretical ethanol yield at a temperature above 40 °C, but it cannot accommodate pentose [59]. Hansenula polymorphais another thermotolorant species with an optimized temperature of 37 °C, and its fermentation operation is possible up to a temperature of 48 °C. Kluyveromycesand H. polymorphaare suitable for SSF processes [60]. P. stipitisis another naturally fermenting pentose and hexose. It can be used for SSF set-up even though its optimized growth temperature is around 30 °C [53,55].
### 5.4. Ethanol recovery
The ethanol production is coincided with yeast cell growth in fermentation, hence the yeast is a by-product of the process. Pure yeast is a value-added product of the process and can inevitably decrease the net cost of the process [53]. Currently, centrifugation is applied to separate yeast cells from ethanol, which is an expensive process with a high energy demand. Yeast cell immobilization technologies using inert carries or chemicals have also been applied in ethanol industry for separating ethanol from cells [53]. Alternatively, yeast flocculation process was introduced in the 1980s and commercialized in 2005 in China and comprehensively used in brewing industry. It involves lectin-like proteins and selectively binds the mannose resides of cell wall of adjacent yeast cell. In this flocculation process, calcium ions are needed and the flocculation occurs spontaneously [61-63]. Upon formation, the flocs would either sediment (large yeast) or rise to the surface (ale yeasts). This flocculation process has the advantages of 1) allowing greater yeast cell biomass concentrations because of no inert carrier; 2) being a simpler and more economically competitive process and 3) fostering the yeast cell viability because the continuous renewal of cells resulting from breaking up of relatively large flocs. The yeast flocs can be purged from the fermenter maintaining the biomass concentration inside the fermenter at specified levels [64]. Different configurations of immobilization process are available for industry: airlift, single packed column, two-stage packed column and CO2 suspended bed [64].
### 5.5. SPORL and dilute acid ethanol production processes
Sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) has been developed by the U.S. Forest Service, Forest Products Laboratory and the University of Wisconsin-Madison as a promising biorefinery process to produce ethanol from cellulosic materials [32,65,66]. The SPORL process has a short chemical pretreatment at a high temperature to remove recalcitrance of the substrate without a significant delignification, and a disk refiner to increase the surface area, which is necessary for the sugar dissolution in the latter stages for fermentation. The potential products of the SPORL process are ethanol, hemicellulosic sugars and lignosulfonate [67]. Figure 2 shows the process diagram of the SPORL process. As can be seen, the wood chips are pretreated with bisulfite and/or sulfuric acid at a temperature of 160-190 °C, a pH of 2-5, and liquid/wood ratio of 2-3 for 10-30 min. The bisulfite charge is 1-3% and 6-9% for hardwood and softwood species, respectively, and acid ranges between 1 and 2% [68]. The solid substrates of the chemical treatment are then fibrilized using a mechanical disk refiner. The chemical pretreatment has a direct effect on the refining stage of the SPORL process. Subsequently, the solid substrate is enzymatically hydrolyzed, fermented, and distilled to produce ethanol [67]. Hemicelluloses are also isolated from the spent liquor and fermented to ethanol, while lignosulfonate is a by-product of this process. Softwoods species have usually poor digestibility in enzymatic saccharification [65]. The SPORL process is particularly effective in improving the enzymatic saccharification efficiency of softwoods.
Alternatively, ethanol can be produced by pretreating biomass with sulfuric acid, and subsequent mechanical pulping (refining) of the pretreated biomass. This process is called dilute acid process. However, a high temperature and a very low pH of this process impart serious equipment corrosion problems [70].
It was reported that the SPORL pretreatment was more efficient than the dilute acid pretreatment for recovering sugars from the solid substrate and spent liquor. Inhibitors were more in the spent liquor of the dilute acid pretreatment, but the concentration of lignin was higher in the spent liquor of the SPORL pretreatment. Due to the lower inhibitors presented in the spent liquor, the ethanol production would be facilitated with the SPORL system. The ethanol production from the substrate and spent liquor of pine species under various SPORL pretreatment conditions at 180 °C for 25 min and then fermenting via using S. cerevisiae(ATCC 200062) at 32 °C for 72 h at 100 rpm are listed in Table 2 [70].
Acid charge, % Bisulfate charge, % Initial pH Substrate ethanol1 Substrate ethanol efficiency2 Hydrosate ethanol1 Hydrolysate ethanol efficiency2 Total ethanol yield 2.21 4 1.8 136.7 73.7 52.8 65.1 189.5(49.2) 2.21 8 1.9 209.4 83.8 66.9 94.2 276.3(71.7) 1.4 8 2.3 193.2 76.4 36.3 70.4 229.5(59.6) 0 8 4.2 165.6 69.6 1.7 11.3 166.7(43.3)
### Table 2.
Ethanol production in the SPORL system of pine species under various conditions [70].
As can be seen, by increasing the bisulfite concentration from 4% to 8%, the ethanol production and efficiency were increased for both the substrate and spent liquor, resulting in 21% increase in the total ethanol production. It is also noticeable that the ethanol production from the substrate or spent liquor was reduced by reducing the acid charge (increasing pH) of the pretreatment.
## 6. Butanol production
Although ethanol has been considered as a promising biofuel, it has several drawbacks: the heat value of ethanol is 27 MJ/kg, while that of FT-diesel is 42.7 MJ/kg implying that ethanol contain a much lower energy density compared with diesel fuel used in automobile industry [2,12]; it has also a high water solubility that prevents it from being an ideal biofuel, and high concentration ethanol blends can cause corrosion of some metallic components in tanks and deterioration of rubbers and plastic used in car engines [2]. Consequently, the incentives for obtaining a better alternative biofuel are high.
The industrial synthesis of biobutanol was commenced during 1912-1914 by acetone-butanol- ethanol (ABE) fermentation of molasses and cereal grains using clostridium acetobutylicum[71]. However, butanol was primarily used as a solvent for the production of other chemicals prior to 2005. Butanol has similar energy density and polarity to those of gasoline [71]. It has an adequate blending ability with gasoline and compatibility to combustion engines [72]. It can be shipped through existing fuel pipelines, whereas ethanol must be transported via rail and truck [73,74]. It has octane-improving power and low volatility (six times less than the volatility of ethanol). These novel properties made butanol a promising biofuel [75]. The economics of butanol fermentation is favorable even with the present technology [76]. However, the capital cost of butanol fermentation is presently higher, but its production cost is less, than that of petrochemical process to produce butanol [77]. Despite steadily growing production, its market remains tight and its price high due to low investment and hefty demand in coming years [76].
### 6.1. Butanol fermentation process
To produce butanol via fermentation as the second generation biofuel, cellulose should be initially converted to glucose, as most of the butanol-fermenting microorganisms can digest glucose and not cellulose. Similar to ethanol production, the enzymatic hydrolysis of polysaccharides to monosaccharides and then fermentation to biosolvents were carried out in the past [78]. The drawbacks of this process is its energy intensity, which makes its commercialization costly [78,79].
The production of butanol from cellulose mainly relies on the application of clostridiaspecies (C. acetobutylicum, C. beijerinckii, C. pasteurianum). Clostridiaacetone-butanol-ethanol (ABE) fermentation from carbohydrates used to be the largest biotechnological process second to yeast ethanol fermentation and the largest process ever conducted under sterile conditions [72,76]. Clostridiaspecies have several advantages: their thermophilic nature permits their utilization at a high temperature of 60 °C (facilitates sterilization process), they can digest pentoses, and more interestingly they can ferment cellulose, which implies that cellulose hydrolysis to glucose and glucose fermentation can be proceeded spontaneously. Butanol can only be generated if the cells enter sporulation process, but this process discourages cell growth. Thus, balancing cell growth and sporulation timing is a key factor influencing the carbon flow towards cell growth and butanol generation [74]. However, these species have some disadvantages including the low solvent resistance, comparative difficulty in genetic modification, and increased energetic demand for cellulase production under anaerobic environments [80].
In the ABE process, the coproduction of acetone, butanol and ethanol causes a poor selectivity with respect to butanol production. The theoretical mass and energy yields of ABE fermentation are 37% and 94%, respectively [81]. It was reported that the substrate costs account for 60% of the total production cost, and the butanol production will not be feasible if the fermentation yield is less than 25% [80]. The best results reported for the ABE process were 8.2 g/l acetone, 2.2 g/l ethanol and 17.6 g/l butanol [82].
### 6.2. Production improvement
The production of butanol faces some challenges: 1) selection of sustainable biomass 2) low production rate, 3) constrains executed on butanol inhibition and 4) high product recovery costs [72,83]. Different strategies can be performed to improve the production of butanol via fermentation as described in the following sections.
#### 6.2.1. Eliminating inhibitors
The phenolic compounds of cellulosic materials inhibit the butanol fermentation process (similar that of ethanol fermentation process) [78]. In one study, the majority of inhibitory compounds were phenolic compounds, while furfural and hydroxymethyl furfural (HMF) did not affect the cell growth and ABE fermentation [84]. It was reported that, during the initial growth phase of cells, other by-products were also produced such as acetic acid and butyric acid, which inhibited the butanol production [84]. In one study, the presence of 1 g/l ferulic acid and vanillin acid reduced the cell growth by 70% and 56%, respectively [84]. The choice of detoxification method would depend on the compositions of hydrolysates and the species of fermenting microorganism [84]. Previously, lime treatment [85], evaporation, adsorption using ion exchange resins and activated carbon were used prior to fermentation as detoxification methods for butanol production [84]. However, the detoxification efficiency depends on the chemical structure of inhibitors [84]. Other inhibitors of the ABE process are substrate inhibition, salt concentration, presence of dead cells, low water activity, O2 diffusion, macromolecules accumulation and nutrient deficiency [86].
#### 6.2.2. Removal of butanol
Clostridiaspecies are known to be solventogenic in producing acetone, butanol, and ethanol, but are still subjected to negative inhibition by their own products [72,74]. The hurdles are being resolved using genetic engineering techniques, metabolic engineering strategies and integrated continuous fermentation processes [72]. In this context, one study showed that the presence of butanol at a concentration of higher than 7.4 g/l impaired the cell growth [87,88]. In this case, butanol may penetrate the cytoplasmic membrane and disrupt several physicochemical characteristics of the cells [72]. On the contrary, the ClostridiumBOH3 species showed the advantage of high resistance against butanol (up to 16 g/l) [74].
In the literature, the simultaneous production and the removal of butanol was carried out in order to maintain a low butanol concentration in the fermentation medium (broth) using liquid-liquid extraction, adsorption, perstraction, reverse osmosis, pre-evaporation and gas stripping [89], among which gas stripping has received great attentions. Gas stripping offers several advantages including feasibility and simplicity of the process, reduction in butanol concentration without affecting culture, concentration of nutrients and reaction intermediates [86]. Furthermore, a membrane separation with super critical extraction may be a feasible method in butanol removal in future [72].
#### 6.2.3. Modifying microorganism
One alternative to increase the butanol production was reported to be the genetic engineering for strain improvement with insertion of butanol producing gene of Clostridiain high butanol tolerant organisms. In this context, the genetic manipulating of Clostridiawas reported to decrease its sensitivity to the presence of butanol, which eventually increased the butanol concentration up to 17.8 g/l in the fermentation medium [87]. Also, research on aerobic producing butanol using genetically engineered organics like, E. coli, are being attempted [72]. The strain improvement is effective in improving the yield, but has marginal influence on the economics.
### 6.3. Process configuration
The fermentation of glucose to butanol can be conducted in batch or continuous process. Generally, continuous butanol processes, (free cells, immobilized cells, and cell recycling) are more economical over batch processes. Other advantages are the reduction in sterilization and inoculation times and the superior productivity. In free cell continuous fermentation, cells are free to move within the fermentation broth due to agitation or air lifting. This maintains the microbial cells and nutrients in the suspension and helps in promoting mass transfer [72]. In immobilized cell fermentation, cells are stationary, which have the advantages of the long survival time of cells in solventogenic phase. In one study, immobilized cell fermentation using C. acetobutylicumproduced 20% higher butanol yield than did free cell fermentation [90]. However, the scale up process using immobilized technology seems to have technical problems due to excessive cell growth in the packed beds and blockage [85]. Recycling technique using a membrane technology (e.g. filter) after the fermentation has also been attempted in the literature and the results showed 10 times higher cell concentration and 6 times higher butanol production compared with conventional continuous process using C. saccharoperbutylacetonicum[85]. On the contrary, batch process has a less capital cost and contamination problem (sterilization) in fermentation, and is more flexible.
## 7. Hydrogen production
Hydrogen has been considered as one of the major energy carriers in future due to its high energy content and its capability to overcome the air pollution and global warming [91]. Renewable carbohydrates (e.g. cellulose) are suitable raw materials for hydrogen production, i.e. second generation biofuel, because they are less expensive than other hydrogen carriers, e.g. hydrocarbons, biodiesel, methanol and ethanol [3,37]. Glucose is widely used substrate for hydrogen production [37]. Today, the production cost of hydrogen from renewable biomass is appealing ($60/dry ton or$ 3.6 per GJ) [15]. The most important energy application of hydrogen is transportation, especially for light-duty vehicles [3]. However, the large scale implementation of the hydrogen economy has some obstacles: sustainable hydrogen production, high density hydrogen storage, hydrogen distribution infrastructure, fuel cell cost and life time, and safety concerns [3]. Thus, new technologies and strategies should be developed to make the hydrogen production more economically attractive and industrially feasible [14].
### 7.1. Hydrogen production processes
Table 3 lists various pathways to produce hydrogen from glucose [3]. As can be seen, the theoretical and practical yields of hydrogen production via chemical catalytic reactions, i.e. gasification, pyrolysis and hydrolysis (accompanied by aqueous phase reforming (APR)), of glucose are in a similar range. The gasification is conducted at a high temperature of 1000 K in the presence of oxygen and water. Pyrolysis is carried out at a high temperature but in the absence of oxygen. The main advantage of APR over gasification is the lower extent of undesirable decomposition reaction [3]. The APR is carried out at a lower temperature (400-550 K) and a medium pressure (50-70 bar) [3]. The water medium of this process promotes the occurrence of the hydrogen production reaction. Although the chemical catalytic reaction seem to have considerably higher hydrogen production yields, their prerequisite high energy input and poor selectivity toward hydrogen production are barriers in their industrial implementations.
However, the biological conversion of cellulose to hydrogen is performed at much lower temperatures, which implies that the energy input of this process is much lower than that of chemical catalytic processes. In contrast, the theoretical and practical yields of hydrogen production via this method are rather low (see dark anaerobic fermentation in Table 3) [30,92,93]. In principle, up to 12 mol of hydrogen can be produced per mole of glucose and water via fermentation. However, natural microorganisms produce as much as 4 mol of hydrogen/ mol of glucose along with 1 mol of acetate [94]. The current yield of hydrogen production in cellulose fermentation ranges from 1 to 2 mol H2/mole of hexose sugar [95]. To increase the hydrogen yield, a bioelectrochemically-assisted microbial fuel reactor was reported to convert 2 mol of acetate to up to 8 mol of hydrogen with the aid of electricity [96]. In this respect, the overall production yield of hydrogen increased to 9 mol per mol of glucose [96]. However, this process also needs electricity input and has not been studied in large scales.
Method Theoretical yield, % Practical yield, % Energy efficiency, % Dark fermentation (DF) 4 1-3.2 10-30 DF+ electricity-assisted microbial fuel cell 12 9 75 Ethanol fermentation/partial oxidation reforming 10 9 60 Gasification 12 2-8 35-50 Pyrolysis 12 2.5-8 30-50 Hydrolysis+ aqueous reforming 12 6-8 30-50 Synthetic pathway biotransformation 12 12 122
### Table 3.
Methods for converting glucose to hydrogen as biofuel [3].
Synthetic pathway biotransformation is a new biocatalytic technology based on the application of enzymes to convert cellulose to hydrogen. This process is much simpler than biological treatments. The biotransformation of carbohydrates to hydrogen by cell-free synthetic pathway (enzymes) has numerous advantages: high production yield (12 H2/glucose unit), 100% selectivity, high energy conversion efficiency (122% based on combustion energy), high purity hydrogen generated, mild reaction conditions, low cost bioreactor and no toxicity hazards. In one study using 2 mM cellubiose concentration as the substrate, the overall yields of hydrogen and CO2 were 11.2 and 5.64 mol per mol of anhydroglucose unit corresponding to 93% and 94% of the theoretical yields, respectively [97]. Furthermore, these enzymatic reactions are reversible, thus the removal of products favors the unidirectional reaction towards the desired products. One study on the biotransformation of starch and water revealed that these reactions were spontaneous and endothermic (∆G0= -49.8 kJ/mol, ∆H0=+598 kJ/mol). Thus, these reactions are driven by entropy gain rather than enthalpy loss [3]. Such entropy-driven reactions can generate more output chemical energy in the form of hydrogen than input energy in the form of polysaccharides [97]. This is very interesting as most of the chemical conversions of cellulose/glucose to biofuel are exothermic. In other words, the output biofuel has less energy than do raw materials, i.e. cellulose/glucose. However, this method currently has a low hydrogen production rate [3]. Research in this area is on-going and no concrete conclusion has been made yet.
### 7.2. Biological production of hydrogen
The biological production of hydrogen has received great attentions due to its potential as an inexhaustible, low-cost and renewable source of clean energy [91]. The photosynthetic production of hydrogen basically uses CO2 and water via direct photolysis. The yield of this process is high, but there is a shortage of photobioreactors on large scales, which constrains its investigation in laboratory scales [98]. Compared to photosynthesis, anaerobic hydrogen production process is more feasible (less expensive), has higher rates and thus has been widely studied [99]. This process seems to be closer to be implemented in commercial scales.
Several breakthroughs have been made in understanding the fundamentals of hydrogen production including the isolation of microbial strains with a high hydrogen production capacity and the optimization of the microbial fermentation process [100,101]. The performance of anaerobic fermentation depends on a number of factors, e.g. temperature, pH, alkalinity oxidation-reduction potential, particle size of lignocellulosic materials, substrate content and inoculum source [91,102]. It was reported that the optimized pH for producing hydrogen in a dark fermentation is between 5.5 and 6.7 [102]. However, there are contradictory reports about the influence of ethanol on hydrogen production in dark fermentation processes in that some studies reported a possible competition between ethanol and hydrogen production [103-105], while others reported a high hydrogen production accompanied by a high ethanol production [106,107]. In another study, the addition of ethanol to the growth medium at the initiation of the fermentation process resulted in 54% H2 and 25% acetate increases, respectively, using C. Thermocellumbacteria [108].
In addition to hydrogen, organic acids are produced in dark fermentation. To achieve adequate overall energy efficiency, the energy stored in the organic acids produced in the dark fermentation processes should also be utilized. This can be conducted via combining the concepts of dark fermentation and anaerobic digestion [109].
On the contrary, dark fermentation has some drawbacks: 1) poor yield per substrate in the conversion of biomass to H2 by microbial fermentation; 2) sensitivity to end-product accumulation; and 3) high environmental and economic costs of biomass production to generate fermentable substrate [13,110-112].
### 7.3. Microorganisms to produce hydrogen
Thermophilic cellulosic bacteria promote their greater operating temperature to produce hydrogen, which facilitate biomass pretreatment, maximize enzymatic reaction rates, and favor the equilibrium point of H2 in direction of H2 production [13,14]. Clostridium thermocellumand caldicellulosiruptor saccharolyticushave been the main focus of hydrogen production research [95]. Caldicellulosiruptor saccharolyticusis a gram-positive and extremely thermophilic, has been reported to produce hydrogen from cellulose even at a high temperature of 70 °C, and is the most promising candidate for large scales hydrogen production [98,113]. Hydrogen has been reported to be produced from pentoses via using thermophile Caldicellulosiruptor saccharolytricuswith a high yield of 334.7 ml H2/g of sugar accounting for 67% of maximum theoretical yield of 497.6 ml H2/g of sugar [37,114,115]. Furthermore, the optimum pH in the fermentation of cellulose to produce hydrogen via C. Thermocellumwas between 7 and 7.2 [116].
In the literature, some mesophilic bacteria have been investigated for hydrogen production including Clostridium cellulolyticum, Clostidium ellulovorans, Clostridiumphytofermentansand Clostridium termitidis. However, their low operating temperature (32-40 °C) introduces additional operating units to the hydrogen production process and increases the risks in process operations, which constrains the practical implementation of mesophilic bacteria in large industrial scales [3].
### 7.4. Fermentation culture
Although the pure culture usually provides a high production efficiency, it is difficult to apply in industrial scales. In fact, the preparation of pure cultures in indutrial scales is difficult and expensive, which will definitely affect the production cost of hydrogen. Instead, hydrogen can be produced with mixed cultures. The mixed culture has been claimed to be more effective in substrate conversion than pure culture [95].
However, mixed culture may encounter the drawbacks of the competition of substrates with non-hydrogen producing microbial population as well as the consumption of produced hydrogen by hydrogen consuming bacteria. One alternative to address this difficulty is to pretreat the mixed culture with base, heat and/or an anaerobic condition, which eliminates/inhibits the non-producing/consuming hydrogen bacteria [34,113,117]. Heat pretreatment is commonly used in anaerobic fermentation in order to improve the hydrogen production by activating spore-forming clostridiumand inhibiting hydrogen consuming non-spore-forming bacteria. However, the heat pretreatment might inactivate hydrogen producing bacteria existing in natural feedstock [34,37]. The elucidation of anaerobic activated sludge microbial community utilizing monosaccharides will be an important foundation towards the industrialization of hydrogen production. In one study, a mixed microbial culture was obtained via the anaerobic activation of sludge in a continuous stirred-tank reactor (29 days of acclimatization) [118]. In this study, glucose had the highest specific hydrogen production rate (358 mL/g.g of mixed liquid volatile suspended solid) and conversion rate (82 mL/g glucose) among glucose, fructose, galactose and arabinose under the fermentation conditions of 35 °C and pH of 5 [34,118].
### 7.5. Improving production efficiency
#### 7.5.1. Dark fermentation
The presence of hydrogen in fermentation reactors seems to affect the performance of dark fermentation process. It was reported that sparling the bioreactor with nitrogen would bring the concentration of hydrogen at a low level in the fermentation. Alternatively, using hollow fiber silicone rubber membrane effectively reduced biogas partial pressure in the fermentation resulting 10% improvement in the rate and 15% increase in the yield of hydrogen production [119]. To improve the hydrogen production, some strategies were carried out in the literature involving bioprocess engineering and bioreactor design that maintains a neutral pH during fermentation and ensures the rapid removal of hydrogen and CO2 from the aqueous phase [95].
#### 7.5.2. Enzymatic treatment
Enzymes applied in the biotransformation of hydrogen are expensive. A combination of enzyme immobilization and thermo stable enzymes was reported to increase the life time of enzyme used for hydrogen production [120]. In one study, changing the process parameters (e.g. temperature, enzyme concentration, substrate concentration and metabolic channeling) in enzymatic reaction were reported to affect the hydrogen production rates [3]. A conservative estimation reported that the hydrogen production rates could increase to 23.6 H2/l/h using a high-cell density [121]. The over-expression of enzymes catalyzing reactions towards the desired product is another method to increase the hydrogen production. The heterologous gene expression of pyruvate decarboxylate and alcohol dehydrogenase from Zymomonas mobiliswithin C. cellulolyticumwas shown to increase the hydrogen yield by 75%, while that of acetate and ethanol increased by 93% and 53%, respectively [122].
### 7.6. Process configuration
Similar to ethanol production, hydrogen production can be conducted in a one- or two-stage process. The simultaneous saccharification and fermentation process, i.e. one-stage process, is less expensive and more commercially feasible, but may be less efficient since the preferred conditions for cellulose degradation and dark fermentation could be significantly different [14]. An important parameter in this process is to choose a microorganism, such as thermococcus kodakaensis, clostridium thermolacticumand clostridium thermocellum, that has the capability to produce cellulolytic enzymes and hydrogen simultaneously [14,123]. In this process, the production rate and efficiency are limited by enzymatic saccharification. The two-stage hydrogen production process, on the other hand, is performed via cellulose hydrolysis in one stage and fermentation of the hexose in another stage [124]. This process might be more effective in terms of hydrogen yield, but it is more complicated.
## 8. Production of furan-based biofuel
Recently, a new second generation biofuel was introduced via the chemical conversion of cellulose. In this approach, hydroxymethyl furfural (HMF) is initially produced from cellulose, and HMF is subsequently converted to 2,5-dimethylfuran (DMF). DMF has an energy content of 31.5 MJ/l, which is similar to that of gasoline (35 MJ/l) and 40% greater than that of ethanol (23 MJ/l) [1]. DMF (bp 92-94 °C) is less volatile than ethanol (bp 78 °C), and is immiscible with water, which makes it an appealing liquid biofuel [1].
Figure 3 shows the process block diagram of DMF production from fructose. This process contains two main parts: 1) HMF production and its purification and 2) DMF production from HMF and its downstream purification.
Two-solvent catalyst system of butanol/water (at 180 °C) was proposed for producing HMF from fructose [1]. In this process, the conversion of glucose/fructose takes place in the aqueous phase (with HMF yield of 83%), in which HCl acts as a catalyst to convert fructose to HMF. Also, NaCl is added to the system and enhances the transportation of HMF from aqueous phase to organic phase (butanol), which prevents HMF from further degradation in the aqueous phase. Afterwards, the HMF is purified via various distillation/separation units and butanol is recycled to the HMF production reactor [1].
In another study, methyl isobutyl ketone (MIBK)/water system (in the present of TiO2 and 250 °C) resulted in 35% HMF yield from glucose [125,126]. In this respect, ionic liquids, e.g.1-ethyl-3-methyl-imidazolium chloride ionic (in the presence of LiCl, CuCl or CrCl) showed a higher yield (>65%) at a temperature of 160 °C [127,128]. In another research, dimethyl sulfoxide (DMSO) was used as solvent to produce HMF from glucose with HMF yield of 53% [129]. However, these solvents are usually toxic and difficult to prepare, and their separation process from HMF is challenging [129]. These drawbacks will most likely limits their application in producing HMF in laboratory scales.
Alternatively, the hydrothermal conversion of cellulose to HMF (275-300 °C for less than 30 min) in homogenous systems in the presence of sulphuric acid resulted in a 20% HMF yield. However, this system under a neutral condition produced a lower yield (<16%), but a product (HMF) with a higher purity (50-60%) [130]. In another research, the yield of HMF from fructose was 65% in the presence of phosphoric acid, which was conducted at 228 °C for less than 5 min [1]. The most promising and industrially attractive method to produce HMF was the acetic acid/water mixture (10 g/l acid at 200 °C for 20 min), which resulted in the production of HMF from fructose with 60% yield [131]. This process resulted in 53% HMF yield under the same conditions, but without acetic acid [131]. Alternatively, the hot compressed water treatment of cellulose at a temperature of 523 K for 5 min (pressure 2.5 MPa under nitrogen) produced 15% HMF, and the addition of 10% (wt.) TiO2 to the system increased the yield to 28% [1]. This method is more feasible than other homogenous catalytic methods, as the catalyst in this system can be easily separated and thus recycled to the system [132]. Furthermore, the addition of acetone to water/TiO2 system induced a higher HMF yield (35%). This process was conducted under atmospheric condition, which is more industrially attractive, but the presence of acetone in the system brings recycling issues and uncertainties at large scale applications [1].
The produced HMF in Figure 3 will be fed into a PFTR reactor, in which H2 is added (in the presence of chromium II or copper-ruthenium-carbon catalysts) that is necessary for the conversion of HMF to DMF [6]. Finally, DMF is purified using several distillation/separation processes, and the organic solvent (butanol) is recycled to the system (Figure 3).
However, this process has several drawbacks: 1) it uses hydrogen which is a biofuel and currently expensive; 2) it uses butanol (another biofuel) as a solvent, which brings difficulties to its large scale implementations; 3) it uses NaCl to enhance the extraction of HMF from aqueous phase to organic butanol. NaCl introduces uncertainties in the downstream processes and its removal is cost intensive; 4) as described above, expensive chromium II or copper-ruthenium-carbon was used as a catalyst in the PFTR reactor [6]. It was reported that the production cost of DMF using this process is approximately 2 $/l, which is not presently economical. The process optimization seemed to lower the production cost to approximately 1$/l, which is still high and not competitive with other appealing biofuels [6].
Alternatively, cellulose can be converted to 5-chloromethylfurfural (CMF) via heating cellulose in concentrated HCl at the presence of LiCl. Subsequently, the products should be extracted with 1,2-dichloroethane. This process yielded 71% CMF in one study [133]. The CMF was then converted to DMF and 5-ethoxymethylfurfural. This process yielded 84% isolated DMF, but the presence of LiCl is considered as one drawback of this system [133]. Alternatively, the CMF was converted to ethoxymethylfurfural (EMF) via stirring in ethanol solution. EMF has a boiling point of 235 °C, and energy density that is similar to energy density of gasoline and 40% higher than that of ethanol [133]. The EMF can also be used a biofuel, but this process seem to be complicated and faces with several technological challenges.
The most important parameters affecting the production cost of DMF via the aforementioned process are feedstock cost, production yield, by-product prices, catalyst cost, and total purchased equipment cost [6]. The productions of DMF and CMF are not feasible using current technologies. Although these chemicals were produced at laboratory scales, their commercialization is under serious questions as their production processes require various expensive solvents that are not easily recycled. The separation and purification of final products from solvents are also costly.
## 9. Conclusions
The pretreatment of woody materials is an important step for producing biofuels via fermentation. The physicochemical pretreatment is the most promising approach to dissemble cellulosic biomass. Enzymatic hydrolysis is very selective in terms of decomposing cellulose chains, but its process conditions are not very industrially attractive. However, acid hydrolysis is fast with a high yield, but it produces some by-products. These by-products are inhibitors of downstream fermentation processes and hence should be removed from the process prior to fermentation. Adsorption and evaporation have been the most successful approaches to eliminate these inhibitors in detoxification stages prior to fermentation. S. cerevisiae, C. acetobutylicumand C. thermocellumare the most promising microorganisms for ethanol, butanol and hydrogen productions, respectively. Presently, the major challenges in the production of these biofuels are the rather low production yield of biofuels and the sensitivity of microorganisms to the presence of inhibitors and biofuels in the fermentation media. The productions of ethanol and butanol from woody biomass are close to be commercialized, but hydrogen production is still facing with difficulties in increasing the production rate. Although 2,5-dimethylfuran (DMF) has appealing properties and can be potentially used as biofuel, its production with present technologies is not economical and more industrially attractive processes should be developed in order to have a commercialized DMF process.
## Acknowledgement
The author would like to thank NSERC Canada for providing funds for this review research.
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Written By
Pedram Fatehi
Submitted: November 3rd, 2011 Reviewed: June 17th, 2012 Published: August 29th, 2013
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http://tex.stackexchange.com/questions/83667/how-to-insert-an-image-inside-a-paragraph
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How to insert an image inside a paragraph?
I'd like to insert a small image inside a paragraph, aligning it with the text. The following snapshot depicts what I have in mind. Notice the image at the end of the last line.
-
Nothing prevents you from using \includegraphics in a paragraph. There is no need to insert it in a figure environment: for TeX it's just like a letter (almost, but the details don't concern this application). – egreg Nov 21 '12 at 13:01
Use \includegraphics from graphicx:
\documentclass{article}
\usepackage{lipsum}
\usepackage{graphicx}
\begin{document}
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Ut purus elit,
vestibulum ut, placerat ac, adipiscing vitae, felis. Curabitur dictum gravida
mauris. Nam arcu libero, nonummy eget, consectetuer id, vulputate a, magna.
Donec vehicula augue eu neque. Pellentesque habitant morbi tristique senectus
et netus et malesuada fames ac turpis egestas. Mauris ut leo. Cras viverra
metus rhoncus sem. Nulla et lectus vestibulum urna fringilla ultrices. Phasellus
eu tellus sit amet tortor gravida placerat. Integer sapien est, iaculis in, pretium
quis, viverra ac, nunc. Praesent eget sem vel leo ultrices bibendum. Aenean
faucibus. Morbi dolor nulla, malesuada eu, pulvinar at, mollis ac, nulla. Cur-
abitur auctor semper nulla. Donec varius orci eget risus. Duis nibh mi, congue
eu, accumsan eleifend, sagittis quis, diam. Duis eget orci sit amet orci dignissim
rutrum.\includegraphics[scale=0.02]{example-image}
\end{document}
I have used scale here just to reduce the image (I don't have a small image right now). You may opt not to use it.
-
As an alternative to scale, you could also use the width and/or height key to make sure the image comes out the right size in the text. This way, the code does not depend so much on specifics of the image. – Charles Staats Nov 21 '12 at 13:17
depending on the shape of the image relative to the text, you may want to apply (negative) \raisebox to the image to improve the positioning. if the image is being used more than once, it's efficient to pack it into a \savebox and then use it later. for example, \newsavebox{\mybox} \savebox{\mybox}{\raisebox{-.5ex}{\includegraphics[scale=.03]{example-image}}} and then \usebox{\mybox} – barbara beeton Nov 21 '12 at 14:32
You can alternatively define and use a new command for your custom glyph. This is especially useful if you will want to use it more than once.
If you want to fine-tune your output so that your glyph is properly displayed relative to your line of text you can use the [height] argument and \raisebox{} container:
\documentclass{article}
\usepackage{lipsum}
\usepackage{graphicx}
\newcommand*\imge{\raisebox{-0.17\baselineskip}{\includegraphics[height=0.81\baselineskip]{image.jpg}}}
\begin{document}
This is your custom image-based glyph shown inline and typeset however best fits the image: \imge !!!
\end{document}
-
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https://randommathgenerator.com/2013/08/
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## Month: August, 2013
### My first attempt at solving the Lonely Runner Conjecture
Let us suppose there are $k$ runners running at speeds $0 around a field of circumference $1$. Take any runner from the $k$ runners- say $r_i$, who runs with speed $a_i$. Say we pair him up with another runner $r_j$ who runs with speed $a_j$. Then for time $0\leq t\leq\frac{1}{2|a_i-a_j|}$, the distance between them is $|a_i-a_j|t$, and for $\frac{1}{2|a_i-a_j|}\leq t\leq \frac{1}{|a_i-a_j|}$, the distance between them is $1-|a_i-a_j|t$.
The Lonely Runner Conjecture can be stated in the following way: there exists a time $t$ such that $\min\left[\min\{|a_i-a_1|t_1,1-|a_i-a_1|t_1\},\min\{|a_i-a_2|t_2,1-|a_i-a_2|t_2\},\dots,\min\{|a_i-a_k|t_k,1-|a_i-a_k|t_k\}\right]\geq\frac{1}{k}$.
Here $t_1,t_2,t_3,\dots,t_k$ are the smallest positive values found after successively determining $t_x-n\frac{1}{|a_i-a_x|}$, where $x\in\{1,2,3,\dots k\}\setminus\{i\}$, and $n\in\Bbb{Z}^+$
### Proofs of Sylow’s Theorems in Group Theory- Part 1
I will try to give a breakdown of the proof of Sylow’s theorems in group theory. These theorems can be tricky to understand, and especially retain even if you’ve understood the basic line of argument.
1. Sylow’s First Theorem- If for a prime number $p$, $o(G)=p^km$, and $p\nmid m$, then there is a subgroup $H\leq G$ such that $o(H)=p^k$.
First we will try to understand what an orbit of a group is. Take a set $S$, and a group $G$. $S$ does not necessarily have to be a subset of $G$. $Orbit(S)=\{gs|s\in S, g\in G\}$. Note that this is right multiplication.
$Stabilizer(S)=\{g\in G|gs=s\}$.
Now the Orbit-Stabilizer Theorem- $|Orbit||Stabilizer|=|Group|$. Something to remember from this is that there is nothing special about this theorem. It is just another way of saying $|Image||Kernel|=|Group|$, as derived from the First Isomorphism Theorem.
The stabilizer of a set $S$ is a subgroup. Proof: Let $as=s$ and $bs=s$. Then $abs=as=s$. Also, if $as=s$, then taking left inverse on both sides, $a^{-1}s=s$.
Now we move to a combinatorial argument: what power of $p$ divides ${p^km\choose p^k}$? On expanding, we get $\displaystyle{\frac{p^km(p^km-1)(p^km-2)\dots (p^km-p^k+1)}{1,2,3\dots p^k}}=m\displaystyle{\Pi}_{j=1}^{p^k-1}\frac{p^km-j}{p^k-j}$. The highest power of $p$ that can divide $j$ is $\leq k-1$. Hence, the power of $p$ that divides $p^k-j$ is the same that which divides $p^km-j$. In fact, $p$ does not have to be prime for this property to be true. More generally speaking, just to gain a feel for this kind of argument, provided $j\leq p^k-1$, the fraction of the form $\frac{a-j}{b-j}$ not be divided by any power of $p$ except for $1$, as long as both $a$ and $b$ are divisible by powers of $p$ greater than or equal to $k$. $j$ is clearly the constraint here. Remember that $p\nmid m$ is a necessary condition for this.
Now we prove ${p^km\choose p^k}\equiv m (mod p)$.
Now we will define the set $S$ to contain all subsets of $G$ with $p^k$ elements. Clearly, $|S|={p^km\choose p^k}$, which as shown above is not divisible by $p$. Take every $g\in G$, and multiply it with every element of $S$. Note that very element of $S$ is itself a set containing $p^k$ elements of $G$. If $S_i\in S$, then $gS_i\in S$. Moreover, equivalence classes are formed when all elements of $G$ are multiplied with all elements of $S$, and these equivalence classes partition $S$. The proof of this: let $GS_i$ be the orbit of $S_i$. Then if $S_k\in Orb(S_i), gS_i=S_k$. Moreover, if $S_l\in S=g'S_i$, then $g'g^{-1}S_k=S_l$. This gives a feel for why these objects of $S$ are all in the same class.
Let there be $r$ such partitions of $S$. Then $|S|=|S_1|+|S_2|+\dots+|S_r|$, where $S_1,S_2$,etc are partitions of $S$. We know $|S|$ is not divisible by $p$. Hence, there has to be at least one $|S_k|$ which is not divisible by $p$. Let $S_k\in [S_k]$, where $[S_k]$ is an equivalence class partitioning $S$. Consider a mapping $f:G\to S_k$ such that $f(g)=gS_k$. The image is $[S_k]$, and the kernel is the stabilizer. By the orbit-stabilizer theorem, $|G|=|Stabilizer||Orbit|$. We know that the orbit is not divisible by $p^k$. Hence, the stabilizer has to be divisible by $p^k$. Also, the stabilizer is a subgroup.
The rest of the proof will be continued next time.
Today, I will discuss this research paper by Javed Ali, Professor of Topology and Analysis, BITS Pilani.
What exactly is a proximinal set? It is the set of elements $X$ in which for any $x\in X$, you can find the nearest point(s) to it in $X$. More formally, for each $x\in X, \exists y\in X$ such that $d(x,y)=\inf \{d(x,K)\}$.
This article says a Banach space is a complete vector space with a norm. One might find the difference between a complete metric space and a complete vector space to be minimal. However, the difference that is crucial here is that not every metric space is a vector space. For example, let $(X,d)$ be a metric space, satisfying the relevant axioms. However, for $x,y\in X$, $x+y$ not being defined is possible. However, if $X$ is a vector space, then $x+y\in X$. Hence, every normed vector space is a metric space if one were to define $\|x-y\|=d(x,y)$, but the converse is not necessarily true.
What is a convex set? This article says a convex set is one in which a line joining any two points in the set lies entirely inside the set. But how can a set containing points contain a line? Essentially, the the convex property implies that every point the line passes through is contained within the convex space. Convexity introduces a geometrical flavor to Banach spaces. It is difficult to imagine what such a line segment would be in the Banach space of matrices (with the norm $\|\mathbf{A}-\mathbf{B}\|=\mathbf{A}-\mathbf{B}$.
What is a uniformly convex set? This paper says that a uniform convex space is defined thus: $\forall<\epsilon\leq 2\in\Bbb{R}, \exists \delta(\epsilon)>0$ such that for $\|x\|=\|y\|=1$ and $\|x-y\|\geq \epsilon, \frac{\|x+y\|}{2}\leq 1-\delta(\epsilon)$. Multiplying by $-1$ on both sides, we get $1- \frac{\|x+y\|}{2}\geq \delta(\epsilon)$. What does this actually mean? The first condition implies that $x$ and $y$ cannot lie in the same direction. Hence, $\|x+y\|<2$. As a result, we get $\left\|\frac{x+y}{2}\right\|<1$, or $1-\left\|\frac{x+y}{2}\right\|>0$. As $\delta(\epsilon)>0$, and as $1-\left\|\frac{x+y}{2}\right\|$ is bounded, $\delta(\epsilon)$ can be the lower bound of $1-\left\|\frac{x+y}{2}\right\|$.
But what is uniform about this condition? It is the fact that $\delta(\epsilon)$ does not change with the unit vector being considered, and depends only on $\epsilon$.
Now we go on to prove that every closed convex set of every uniformly convex Banach space is proximinal.
This is the second time I’m checking whether I can write a LATEX equation in wordpress.
$o(HK)=\frac{o(H)o(K)}{o(H\cap K)}$
### Why I have nothing better to do than blog :(
After trying to follow blogs by various mathematicians, I have concluded that having a digital presence is pretty darned cool and useful in academia! Hence, in my pursuit of the forever-elusive elixir of “cool”, I have decided to record my progress in Algebraic Geometry through this blog. I’m no expert. But I feel trying to explain concepts to others promotes a higher degree of clarity than self-study, athough this is debatable and most definitely a grey area.
I really do hope Math enthusiasts find this blog to be a useful spot for better explanations of convoluted geometrical/algebraic concepts.
And reaffirm that beneath all the daunting machinery, Math is so simple and beautiful.
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http://archived.moe/a/thread/12509350
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32KiB, 720x480, fmp.jpg
No.12509350
So /a/, I saw this pic in FMP TSR and was inspired.
So now I need pictures. Show me that you understand.
|
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https://aimsciences.org/article/doi/10.3934/krm.2014.7.755
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# American Institute of Mathematical Sciences
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December 2014, 7(4): 755-778. doi: 10.3934/krm.2014.7.755
## Microscopic and soliton-like solutions of the Boltzmann--Enskog and generalized Enskog equations for elastic and inelastic hard spheres
1 Steklov Mathematical Institute of the Russian Academy of Sciences, Gubkina str. 8, 119991 Moscow, Russian Federation
Received March 2014 Revised July 2014 Published November 2014
N. N. Bogolyubov discovered that the Boltzmann--Enskog kinetic equation has microscopic solutions. They have the form of sums of delta-functions and correspond to trajectories of individual hard spheres. But the rigorous sense of the product of the delta-functions in the collision integral was not discussed. Here we give a rigorous sense to these solutions by introduction of a special regularization of the delta-functions. The crucial observation is that the collision integral of the Boltzmann--Enskog equation coincides with that of the first equation of the BBGKY hierarchy for hard spheres if the special regularization to the delta-functions is applied. This allows to reduce the nonlinear Boltzmann--Enskog equation to the BBGKY hierarchy of linear equations in this particular case.
Also we show that similar functions are exact smooth solutions for the recently proposed generalized Enskog equation. They can be referred to as particle-like'' or soliton-like'' solutions and are analogues of multisoliton solutions of the Korteweg--de Vries equation.
Citation: Anton Trushechkin. Microscopic and soliton-like solutions of the Boltzmann--Enskog and generalized Enskog equations for elastic and inelastic hard spheres. Kinetic & Related Models, 2014, 7 (4) : 755-778. doi: 10.3934/krm.2014.7.755
##### References:
[1] L. Arkeryd and C. Cercignani, On the convergence of solutions of the Enskog equation to solutions of the Boltzmann equation,, Comm. PDE, 14 (1989), 1071. doi: 10.1080/03605308908820644. Google Scholar [2] L. Arkeryd and C. Cercignani, Global existence in $L_1$ for the Enskog equation and convergence of the solutions to solutions of the Boltzmann equation,, J. Stat. Phys., 59 (1990), 845. doi: 10.1007/BF01025854. Google Scholar [3] N. Bellomo and M. Lachowicz, On the asymptotic theory of the Boltzmann and Enskog equations: A rigorous $H$-theorem for the Enskog equation,, Springer Lecture Notes in Mathematics: Mathematical Aspects of Fluid and Plasma Dynamics, 1460 (1991), 15. doi: 10.1007/BFb0091358. Google Scholar [4] A. V. Bobylev, Tochnye resheniya uravneniya Boltsmana,, (Russian) [Exact solutions of the Boltzmann equation], 225 (1975), 1296. Google Scholar [5] L. Boltzmann, Vorlesungen Über Gastheorie,, (German) [Lectures on gas theory], (1896). Google Scholar [6] N. V. Brilliantov and T. Pöschel, Kinetic theory of granular gases,, Oxford University Press, (2004). doi: 10.1093/acprof:oso/9780198530381.001.0001. Google Scholar [7] N. N. Bogolyubov, Microscopic solutions of the Boltzmann-Enskog equation in kinetic theory for elastic balls,, Theor. Math. Phys., 24 (1975), 242. Google Scholar [8] N. N. Bogolubov and N. N. Bogolubov, Jr., Introduction to Quantum Statistical Mechanics,, Gordon and Breach, (2010). doi: 10.1142/7623. Google Scholar [9] M. S. Borovchenkova and V. I. Gerasimenko, On the non-Markovian Enskog equation for granular gases,, J. Phys. A: Math. Theor., 47 (2014). doi: 10.1088/1751-8113/47/3/035001. Google Scholar [10] C. Cercignani, V. I. Gerasimenko and D. Ya. Petrina, Many-Particle Dynamics and Kinetic Equations,, Kluwer Academic Publishing, (1997). doi: 10.1007/978-94-011-5558-8. Google Scholar [11] C. Cercignani, On the Boltzmann equation for rigid spheres,, Transport Theory and Statistical Physics, 2 (1972), 211. doi: 10.1080/00411457208232538. Google Scholar [12] C. Cercignani, Theory and Application of the Boltzmann Equation,, Elsevier, (1975). Google Scholar [13] V. I. Gerasimenko and I. V. Gapyak, Hard sphere dynamics and the Enskog equation,, Kinet. Relat. Models, 5 (2012), 459. doi: 10.3934/krm.2012.5.459. Google Scholar [14] S.-Y. Ha and S. E. Noh, Global weak solutions and uniform $L^p$-stability of the Boltzmann-Enskog equation,, J. Differential Equations, 251 (2011), 1. doi: 10.1016/j.jde.2011.03.021. Google Scholar [15] R. Illner and M. Pulvirenti, A derivation of the BBGKY hierarchy for hard sphere particle systems,, Trans. Theory Stat. Phys., 16 (1987), 997. doi: 10.1080/00411458708204603. Google Scholar [16] V. V. Kozlov, Teplovoye Ravnovesie Po Gibbsu i Puankare,, (Russian) [Thermal Equilibrium in the sense of Gibbs and Poincaré], (2002). Google Scholar [17] V. V. Kozlov, Thermal Equilibrium in the sense of Gibbs and Poincar'e,, Dokl. Akad. Nauk, 382 (2002), 602. Google Scholar [18] V. V. Kozlov and D. V. Treshchev, Weak convergence of solutions of the Liouville equation for nonlinear Hamiltonian systems,, Theor. Math. Phys., 134 (2003), 339. doi: 10.1023/A:1022697321418. Google Scholar [19] V. V. Kozlov and D. V. Treshchev, Evolution of measures in the phase space of nonlinear Hamiltonian systems,, Theor. Math. Phys., 136 (2003), 1325. doi: 10.1023/A:1025607517444. Google Scholar [20] M.-Y. Lee, T.-P. Liu and S.-H. Yu, Large-time behavior of solutions for the Boltzmann equation with hard potentials,, Comm. Math. Phys., 269 (2007), 17. doi: 10.1007/s00220-006-0108-z. Google Scholar [21] T.-P. Liu and S.-H. Yu, The Green's function and large-time behavior of solutions for the one-dimensional Boltzmann equation,, Comm. Pure Appl. Math., 57 (2004), 1543. doi: 10.1002/cpa.20011. Google Scholar [22] T.-P. Liu and S.-H. Yu, Green's function of Boltzmann equation, 3-D waves,, Bulletin of Institute of Mathematics, 1 (2006), 1. Google Scholar [23] A. I. Mikhailov, Functional mechanics: Evolution of the moments of distribution function and the Poincaré recurrence theorem,, $p$-Adic Numbers, 3 (2011), 205. doi: 10.1134/S2070046611030046. Google Scholar [24] D. Ya. Petrina and V. I. Gerasimenko, Mathematical problems of statistical mechanics of a system of elastic balls,, Russian Mathematical Surveys, 45 (1990), 153. doi: 10.1070/RM1990v045n03ABEH002360. Google Scholar [25] D. Ya. Petrina and G. L. Garaffini, Analog of the Liouville equation and BBGKY hierarchy for a system of hard spheres with inelastic collisions,, Ukrainian Mathematical Journal, 57 (2005), 967. doi: 10.1007/s11253-005-0242-3. Google Scholar [26] D. Ya. Petrina and G. L. Garaffini, Solutions of the BBGKY hierarchy for a system of hard spheres with inelastic collisions,, Ukrainian Mathematical Journal, 58 (2006), 371. doi: 10.1007/s11253-006-0075-8. Google Scholar [27] E. V. Piskovskiy, On functional approach to classical mechanics,, $p$-Adic Numbers, 3 (2011), 243. doi: 10.1134/S2070046611030095. Google Scholar [28] E. V. Piskovskiy and I. V. Volovich, On the correspondence between Newtonian and functional mechanics,, in Quantum Bio-Informatics IV. From Quantum Infarmation to Bio-Informatics, (2011), 363. doi: 10.1142/9789814343763_0028. Google Scholar [29] P. Resibois, $H$-theorem for the (modified) nonlinear Enskog equation,, Phys. Rev. Lett., 40 (1978), 1409. doi: 10.1103/PhysRevLett.40.1409. Google Scholar [30] S. Simonella, Evolution of correlation functions in the hard sphere dynamics,, J. Stat. Phys., 155 (2014), 1191. doi: 10.1007/s10955-013-0905-7. Google Scholar [31] H. Spohn, On the integrated form of the BBGKY hierarchy for hard spheres, preprint,, , (1985). Google Scholar [32] A. S. Trushechkin, Microscopic solutions of the Boltzmann-Enskog equation and the irreversibility problem,, Proc. Steklov Inst. Math., 285 (2014), 251. Google Scholar [33] A. S. Trushechkin, Irreversibility and the role of an instrument in the functional formulation of classical mechanics,, Theoret. and Math. Phys., 164 (2010), 1198. doi: 10.1007/s11232-010-0100-9. Google Scholar [34] A. S. Trushechkin and I. V. Volovich, Functional classical mechanics and rational numbers,, p-Adic Numbers Ultrametric Anal. Appl., 1 (2009), 361. doi: 10.1134/S2070046609040086. Google Scholar [35] A. A. Vlasov, Many-Particle Theory and Its Application to Plasma,, Gordon and Breach, (1961). Google Scholar [36] I. V. Volovich, The irreversibilty problem and functional formulation of classical mechanics, preprint,, , (). Google Scholar [37] I. V. Volovich, Randomness in classical mechanics and quantum mechanics,, Found. Phys., 41 (2011), 516. doi: 10.1007/s10701-010-9450-2. Google Scholar [38] I. V. Volovich, Bogolyubov equations and functional mechanics,, Theoret. and Math. Phys., 164 (2010), 1128. doi: 10.1007/s11232-010-0090-7. Google Scholar
show all references
##### References:
[1] L. Arkeryd and C. Cercignani, On the convergence of solutions of the Enskog equation to solutions of the Boltzmann equation,, Comm. PDE, 14 (1989), 1071. doi: 10.1080/03605308908820644. Google Scholar [2] L. Arkeryd and C. Cercignani, Global existence in $L_1$ for the Enskog equation and convergence of the solutions to solutions of the Boltzmann equation,, J. Stat. Phys., 59 (1990), 845. doi: 10.1007/BF01025854. Google Scholar [3] N. Bellomo and M. Lachowicz, On the asymptotic theory of the Boltzmann and Enskog equations: A rigorous $H$-theorem for the Enskog equation,, Springer Lecture Notes in Mathematics: Mathematical Aspects of Fluid and Plasma Dynamics, 1460 (1991), 15. doi: 10.1007/BFb0091358. Google Scholar [4] A. V. Bobylev, Tochnye resheniya uravneniya Boltsmana,, (Russian) [Exact solutions of the Boltzmann equation], 225 (1975), 1296. Google Scholar [5] L. Boltzmann, Vorlesungen Über Gastheorie,, (German) [Lectures on gas theory], (1896). Google Scholar [6] N. V. Brilliantov and T. Pöschel, Kinetic theory of granular gases,, Oxford University Press, (2004). doi: 10.1093/acprof:oso/9780198530381.001.0001. Google Scholar [7] N. N. Bogolyubov, Microscopic solutions of the Boltzmann-Enskog equation in kinetic theory for elastic balls,, Theor. Math. Phys., 24 (1975), 242. Google Scholar [8] N. N. Bogolubov and N. N. Bogolubov, Jr., Introduction to Quantum Statistical Mechanics,, Gordon and Breach, (2010). doi: 10.1142/7623. Google Scholar [9] M. S. Borovchenkova and V. I. Gerasimenko, On the non-Markovian Enskog equation for granular gases,, J. Phys. A: Math. Theor., 47 (2014). doi: 10.1088/1751-8113/47/3/035001. Google Scholar [10] C. Cercignani, V. I. Gerasimenko and D. Ya. Petrina, Many-Particle Dynamics and Kinetic Equations,, Kluwer Academic Publishing, (1997). doi: 10.1007/978-94-011-5558-8. Google Scholar [11] C. Cercignani, On the Boltzmann equation for rigid spheres,, Transport Theory and Statistical Physics, 2 (1972), 211. doi: 10.1080/00411457208232538. Google Scholar [12] C. Cercignani, Theory and Application of the Boltzmann Equation,, Elsevier, (1975). Google Scholar [13] V. I. Gerasimenko and I. V. Gapyak, Hard sphere dynamics and the Enskog equation,, Kinet. Relat. Models, 5 (2012), 459. doi: 10.3934/krm.2012.5.459. Google Scholar [14] S.-Y. Ha and S. E. Noh, Global weak solutions and uniform $L^p$-stability of the Boltzmann-Enskog equation,, J. Differential Equations, 251 (2011), 1. doi: 10.1016/j.jde.2011.03.021. Google Scholar [15] R. Illner and M. Pulvirenti, A derivation of the BBGKY hierarchy for hard sphere particle systems,, Trans. Theory Stat. Phys., 16 (1987), 997. doi: 10.1080/00411458708204603. Google Scholar [16] V. V. Kozlov, Teplovoye Ravnovesie Po Gibbsu i Puankare,, (Russian) [Thermal Equilibrium in the sense of Gibbs and Poincaré], (2002). Google Scholar [17] V. V. Kozlov, Thermal Equilibrium in the sense of Gibbs and Poincar'e,, Dokl. Akad. Nauk, 382 (2002), 602. Google Scholar [18] V. V. Kozlov and D. V. Treshchev, Weak convergence of solutions of the Liouville equation for nonlinear Hamiltonian systems,, Theor. Math. Phys., 134 (2003), 339. doi: 10.1023/A:1022697321418. Google Scholar [19] V. V. Kozlov and D. V. Treshchev, Evolution of measures in the phase space of nonlinear Hamiltonian systems,, Theor. Math. Phys., 136 (2003), 1325. doi: 10.1023/A:1025607517444. Google Scholar [20] M.-Y. Lee, T.-P. Liu and S.-H. Yu, Large-time behavior of solutions for the Boltzmann equation with hard potentials,, Comm. Math. Phys., 269 (2007), 17. doi: 10.1007/s00220-006-0108-z. Google Scholar [21] T.-P. Liu and S.-H. Yu, The Green's function and large-time behavior of solutions for the one-dimensional Boltzmann equation,, Comm. Pure Appl. Math., 57 (2004), 1543. doi: 10.1002/cpa.20011. Google Scholar [22] T.-P. Liu and S.-H. 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2018 Impact Factor: 1.38
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https://pos.sissa.it/363/048/
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Volume 363 - 37th International Symposium on Lattice Field Theory (LATTICE2019) - Main session
Details of a staggered fermion data analysis
M. Ammer,* S. Durr
*corresponding author
Full text: pdf
Pre-published on: January 07, 2020
Published on: August 27, 2020
Abstract
We present technical details of an analysis of pseudo-scalar data from a QCD simulation with staggered fermions. The data were obtained close to the physical point with an inverse lattice spacing of about 3 GeV, and $N_f=2+1+1$. We compare different methods of extracting effective masses and decay constants in lattice units. The results of several correlated and uncorrelated fitting methods are compared, both on the simulated data set, and on a synthetically generated data set.
DOI: https://doi.org/10.22323/1.363.0048
How to cite
Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.
Open Access
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http://www.ams.org/joursearch/servlet/PubSearch?f1=msc&pubname=all&v1=65N15&startRec=1
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AMS eContent Search Results
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[1] Karl Larsson and Mats G. Larson. A continuous/discontinuous {G}alerkin method and a priori error estimates for the biharmonic problem on surfaces. Math. Comp. 86 (2017) 2613-2649. Abstract, references, and article information View Article: PDF [2] Dietmar Gallistl. Stable splitting of polyharmonic operators by generalized Stokes systems. Math. Comp. 86 (2017) 2555-2577. Abstract, references, and article information View Article: PDF [3] Mitsuhiro T. Nakao. Numerical verification for solutions to partial differential equations. Sugaku Expositions 30 (2017) 89-109. Abstract, references, and article information View Article: PDF [4] Hélène Barucq, Théophile Chaumont-Frelet and Christian Gout. Stability analysis of heterogeneous Helmholtz problems and finite element solution based on propagation media approximation. Math. Comp. 86 (2017) 2129-2157. Abstract, references, and article information View Article: PDF [5] Bernardo Cockburn, Guosheng Fu and Francisco Javier Sayas. Superconvergence by $M$-decompositions. Part I: General theory for HDG methods for diffusion. Math. Comp. 86 (2017) 1609-1641. Abstract, references, and article information View Article: PDF [6] Peipei Lu, Huangxin Chen and Weifeng Qiu. An absolutely stable $hp$-HDG method for the time-harmonic Maxwell equations with high wave number. Math. Comp. 86 (2017) 1553-1577. Abstract, references, and article information View Article: PDF [7] Wenming He and Zhimin Zhang. $2k$ superconvergence of $Q_k$ finite elements by anisotropic mesh approximation in weighted Sobolev spaces. Math. Comp. 86 (2017) 1693-1718. Abstract, references, and article information View Article: PDF [8] Hailong Guo, Zhimin Zhang and Ren Zhao. Hessian recovery for finite element methods. Math. Comp. 86 (2017) 1671-1692. Abstract, references, and article information View Article: PDF [9] Daniel Peterseim. Eliminating the pollution effect in Helmholtz problems by local subscale correction. Math. Comp. 86 (2017) 1005-1036. Abstract, references, and article information View Article: PDF [10] D. Leykekhman and M. Pruitt. On the positivity of discrete harmonic functions and the discrete Harnack inequality for piecewise linear finite elements. Math. Comp. 86 (2017) 1127-1145. Abstract, references, and article information View Article: PDF [11] Jessika Camaño, Ricardo Oyarzúa and Giordano Tierra. Analysis of an augmented mixed-FEM for the Navier-Stokes problem. Math. Comp. 86 (2017) 589-615. Abstract, references, and article information View Article: PDF [12] Sudipto Chowdhury, Thirupathi Gudi and A. K. Nandakumaran. Error bounds for a Dirichlet boundary control problem based on energy spaces. Math. Comp. 86 (2017) 1103-1126. Abstract, references, and article information View Article: PDF [13] Erik Burman. A stabilized nonconforming finite element method for the elliptic Cauchy problem. Math. Comp. 86 (2017) 75-96. 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The Costabel-Stephan system of boundary integral equations in the time domain. Math. Comp. 85 (2016) 2341-2364. Abstract, references, and article information View Article: PDF [19] Johnny Guzmán, Manuel A. Sánchez and Marcus Sarkis. On the accuracy of finite element approximations to a class of interface problems. Math. Comp. 85 (2016) 2071-2098. Abstract, references, and article information View Article: PDF [20] Maxim A. Olshanskii and Danil Safin. A narrow-band unfitted finite element method for elliptic PDEs posed on surfaces. Math. Comp. 85 (2016) 1549-1570. Abstract, references, and article information View Article: PDF [21] Sören Bartels. Projection-free approximation of geometrically constrained partial differential equations. Math. Comp. 85 (2016) 1033-1049. Abstract, references, and article information View Article: PDF [22] Gabriel N. Gatica, Ricardo Ruiz-Baier and Giordano Tierra. A mixed finite element method for Darcy's equations with pressure dependent porosity. Math. Comp. 85 (2016) 1-33. Abstract, references, and article information View Article: PDF [23] Xiaozhe Hu and Xiaoliang Cheng. Corrigendum to: Acceleration of a two-grid method for eigenvalue problems''. Math. Comp. 84 (2015) 2701-2704. Abstract, references, and article information View Article: PDF [24] Ralf Hiptmair, Carlos Jerez-Hanckes and Shipeng Mao. Extension by zero in discrete trace spaces: Inverse estimates. Math. Comp. 84 (2015) 2589-2615. Abstract, references, and article information View Article: PDF [25] Sören Bartels, Ricardo H. Nochetto and Abner J. Salgado. A total variation diminishing interpolation operator and applications. Math. Comp. 84 (2015) 2569-2587. Abstract, references, and article information View Article: PDF [26] Andrea Bonito and Denis Devaud. Adaptive finite element methods for the Stokes problem with discontinuous viscosity. Math. Comp. 84 (2015) 2137-2162. MR 3356022. Abstract, references, and article information View Article: PDF [27] Tom H. Koornwinder and Stefan A. Sauter. The intersection of bivariate orthogonal polynomials on triangle patches. Math. Comp. 84 (2015) 1795-1812. Abstract, references, and article information View Article: PDF [28] Norbert Heuer and Francisco-Javier Sayas. Analysis of a non-symmetric coupling of Interior Penalty DG and BEM. Math. Comp. 84 (2015) 581-598. Abstract, references, and article information View Article: PDF [29] Thomas Apel, Johannes Pfefferer and Arnd Rösch. Finite element error estimates on the boundary with application to optimal control. Math. Comp. 84 (2015) 33-70. Abstract, references, and article information View Article: PDF [30] Daniele A. Di Pietro, Martin Vohralík and Soleiman Yousef. Adaptive regularization, linearization, and discretization and a posteriori error control for the two-phase Stefan problem. Math. Comp. 84 (2015) 153-186. Abstract, references, and article information View Article: PDF
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http://physicsformom.blogspot.com/2010_02_01_archive.html
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## Friday, February 26, 2010
### Fourier analysis - Sines and integrals
In case anyone is still reading this, now that it is being updated so sporadically, I'm finally managing another post on Fourier analysis. In this post, I'll try to set up a little bit of the math behind the theory. To do so, I'm going to first remind everyone about the sine function, which I wrote about when talking about the Double Slit Experiment. In that post, I said that the sine function was a mathematical representation of a wave. Here is a plot of y = sin(θ):
Now, that looks an awful lot like the sound waves I was looking at with my guitar back in November. Because they are the same. In fact, when I wanted to depict the sound waves graphically, I used the sine and its partner, the cosine to do it. Going back to the post on the double slit experiment, I believed I compared these functions to a part of speech; by using them, I can now describe a whole host of different phenomena that were previously inaccessible. Including sound waves.
Next, I want to talk about integrals. My mother never took calculus and says she has no idea what an integral is, which means I'm going to try to give a brief introduction (without going into details, alas). The first thing I was taught about integrals is that they represent the "area under the curve," and I think that's really all we need to know about them. If I draw a curve on a coordinate system, for example, like the sine curve above, then the integral is the area between the curve and the x-axis. Therefore, we need to know one other thing to define it, and that is the range of the integral. For example, I am going to zoom in slightly on that sine curve, and then I'll take the integral from x = 0.5 to x = 2.5, which is just the area below the curve between those limits, or the region shaded green.
Now, things can get a bit trickier conceptually when the curve crosses the x-axis and becomes negative-valued. In this case, the integral is still the area under the curve, except that it is now negative. This is represented by the yellow shading.
Finally, if you look carefully, you'll notice that the sine function appears to be symmetric. This will be really important for Fourier analysis. If you integrate the sign function over an entire period, the positive part and the negative part cancel each other out, and we're left with a total integral of 0.
I want to make two final comments about integrals. The key to calculus is finding out that you can generally solve for these areas if you know the functional form of the curve (in this case, for example, we know the curve is a sine curve, so I could write down the function representing the area from calculus). And because I know this is the kind of thing that might interest my mom, in math, we represent an integral with a symbol that looks a little bit like an "S". For example, the integral of sin(x) is written like this:
$\int sin\left(x\right)dx$
The "dx" is there partly to let the reader know that the integral is being performed over the x variable.
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https://puzzling.stackexchange.com/questions/84186/math-quiz-from-a-book
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Math quiz from a book [closed]
A student took some exams. The arithmetical average of his grades is 25. He takes another exam today and he gets a 30, so the arithmetical average of his grades becomes 26. How many exams did he take, including today’s one?
Edit: I know how to solve this, it’s from a book, I found it interesting and I posted it for you!
• sorry to close your question! Unfortunately we're quite strict around here about puzzles being puzzles rather than routine mathematics problems; this one is basically a matter of writing down an equation and solving it. Take a look at xnor's answer to the meta question linked in the close message, which lays out the key distinction very nicely. – Gareth McCaughan May 21 '19 at 13:06
• @GarethMcCaughan don’t worry, I didn’t know. Thanks for telling me! – Marybnq May 21 '19 at 14:40
5
Reason:
Let he gave n exams earlier Then total initial total=25n So new average=(25n+30)/(n+1)=26 Solving we get n=4, so he gave n+1=5 exams including today's
• Almost right... – Marybnq May 21 '19 at 11:33
• This is correct; the question asks how many exams were taken, including today's. – Jeff Zeitlin May 21 '19 at 11:49
• rot13: Lbh pbhyq nyfb tb nobhg guvf ol fnlvat gur qvssrerapr bs 5 rknz cbvagf tvirf n 1 cbvag nirentr vapernfr, fb 5/1 = ahzore bs rknzf. Unys n cbvag jbhyq or 5/0.5 = 10 rknzf, rgp. – mkinson May 21 '19 at 12:03
• @JeffZeitlin exactly, be careful. – Marybnq May 21 '19 at 12:39
• Just to let you know, it was 4 – Marybnq May 21 '19 at 21:47
This question might be better fit on the Math Stack Exchange, but I will answer this anyway :)
We get
$$\frac{x+30}{y}=26$$ $$\frac{x}{y}=25$$ where $$x$$ is the total of his exams' results excluding today's exam, and $$y$$ is the number of exams.
We know that
$$\frac{x}{y}+\frac{30}{y}=25+\frac{30}{y}=26$$
Therefore
$$\frac{30}{y}=1$$
so
$$y=30$$
That's how many exams he took, including today's one.
• I know the solution, I found it challenging and I wanted to post it😅 – Marybnq May 21 '19 at 11:31
• By the way it’s wrong, try again! – Marybnq May 21 '19 at 11:31
• @Marybnq it is? Hmm.... – Mr Pie May 21 '19 at 11:47
• Yes, try solving it keeping in mind the arithmetical average rule – Marybnq May 21 '19 at 12:43
• That second fraction should be x / (y-1) as the previous average would not include today's exam – PunPun1000 May 21 '19 at 19:51
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https://www.themathcitadel.com/articles/red-head-step-dist.html
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## The Red-Headed Step-Distributions
#### R. Traylor
Almost every textbook in probability or statistics will speak of classifying distributions into two different camps: discrete (singular in some older textbooks) and continuous. Discrete distributions have either a finite or a countable sample space (also known as a set of Lebesgue measure 0), such as the Poisson or binomial distribution, or simply rolling a die. The probability of each point in the sample space is nonzero. Continuous distributions have a continuous sample space, such as the normal distribution. A distribution in either of these classes is either characterized by a probability mass function (pmf) or probability distribution function (pdf) derived from the distribution function via taking a derivative. There is, however, a third kind.
This class is one rarely talked about, or mentioned quickly and then discarded. This class of distributions is defined on a set of Lebesgue measure 0, yet the probability of any point in the set is 0, unlike discrete distributions. The distribution function is continuous, even uniformly continuous, but not absolutely continuous, meaning it's not a continuous distribution. The pdf doesn't exist, but one can still find moments of the distribution (e.g. mean, variance). They are almost never encountered in practice, and the only real example I've been able to find thus far is based on the Cantor set. This class is the set of red-headed step-distributions-- the singular continuous distributions.
## What is Lebesgue measure?
Measure theory itself can get extremely complicated and abstract. The idea of measures is to give the "size" of subsets of a space. Lebesgue measure is one type of measure, and is actually something most people are familiar with: the "size" of subsets of Euclidean space in $n$ dimensions. For example, when $n=1$, we live in 1D space. Intervals. The Lebesgue measure of an interval $[a,b]$ on the real line is just the length of that interval: $b-a$. When we move to two dimensions, $\mathbb{R}\times \mathbb{R}$, the Cartesian product of 1D space with itself, our intervals combine to make rectangles. The Lebesgue measure in 2D space is area; so a rectangle built from $[a,b]\times [c,d]$ has Lebesgue measure $(b-a)(d-c)$. Lebesgue measure in 3D space is volume. And so forth.
Now, points are 0-dimensional in Euclidean space. They have no size, no mass. They have Lebesgue measure 0. The proof for why this is true gets a bit abstract, dealing with first defining Lebesgue outer measure, and showing a point is covered by a sequence of closed intervals with measure as small as you want, with the smallest possible having outer measure 0. Intuitively, we can simply see that Lebesgue measure helps us see how much "space" something takes up in the Euclidean world, and points take up no space, and hence should have measure 0.
In fact, any countable set of points has Lebesgue measure 0. Even an infinite but countable set. The union of disjoint Lebesgue measurable sets has a measure equal to the sum of the individual sets. Points are certainly disjoint, and they each have measure 0, and summing 0 forever still yields 0. This isn't a formal proof; it is merely a way to establish the intuition. The set $\{0,1,2\}$ has Lebesgue measure 0. But so do the natural numbers $\mathbb{N}$,and the rational numbers$\mathbb{Q}$, even though the rational numbers contain the set of natural numbers.
It is actually possible to construct an uncountable infinite set that has Lebesgue measure 0, and we will need that in constructing our example of a singular continuous distribution. For now, we'll examine discrete and continuous distributions briefly.
## Discrete (Singular) Distributions
These are the ones most probability textbooks begin with, and most of the examples that are familiar.
### Roll a fair die.
The sample space for a roll of a fair die $X$ is $S =\{1,2,3,4,5,6\}$. The PMF is $P(X = x) = 1/6$, where $x \in S$. The CDF is given by the function $P(X\leq x) = \sum_{j\leq x}P(X=j)$ Example: $$P(X \leq 4) = \sum_{j\leq 4}\frac{1}{6} = \frac{2}{3}$$
### Binomial Distribution
A binomial random variable $X$ counts the number of "successes" or 1s in a binary sequence of $n$ Bernoulli random variables. Think a sequence of coin tosses, and counting the number of heads. In this case, the sample space is infinite, but countable: $S = \{0,1,2,\ldots\}$. If the probability of a 1, or "success" is $p$, then the PMF of $X$ is given by $$P(X=x) = {n \choose x}p^{x}(1-p)^{n-x}$$ Note here again that the sample space is of Lebesgue measure 0, but the probability of any point in that space is a positive number.
## Continuous Distributions
Continuous distributions operate on a continuous sample space, usually an interval or Cartesian product of intervals or even a union of intervals. Continuous distribution functions $F$ areabsolutely continuous, meaning that (in one equivalent definition), the distribution function has a derivative $f=F'$ almost everywhere that is Lebesgue integrable, and obeys the Fundamental Theorem of Calculus: $$F(b)-F(a) = \int_{a}^{b}f(x)dx$$ for $a< b$. This $f$ is the probability distribution function (PDF), derived by differentiating the distribution function. Let's mention some examples of these:
### The Continuous Uniform Distribution
Suppose we have a continuous interval $[a,b]$, and the probability mass is spread equally along this interval, meaning that the probability that our random variable $X$ lies in any subinterval of size $s$ has the same probability, regardless of location. Suppose we do not allow the random variable to take any values outside the interval. The sample space is continuous but over a finite interval. The distribution function for this $X$ is given by $$F(x) = \left\{\begin{array}{lr}0&x< a\\\frac{x-a}{b-a}&a\leq x \leq b\\1&x > b\end{array}\right.$$ This is an absolutely continuous function. Then we may easily derive the PDF by differentiating $F$: $$f(x) = \mathbb{1}_{x \in [a,b]}\frac{1}{b-a}$$ where $\mathbb{1}_{x \in [a,b]}$ is theindicator function that takes value 1 if $x$ is in the interval, and 0 otherwise.
This distribution is the continuous version of a die roll. The die roll is the discrete uniform distribution, and here we just allow for a die with uncountably many sides with values in $[a,b]$. The probability of any particular point is 0, however, even though it is possible to draw a random number from this interval. To see this, note that the probability that the random variable $X$ lies between two points in the interval, say $x_{1}$ and $x_{2}$ is given by multiplying the height of the PDF by the length (Lebesgue measure) of the subinterval. The Lebesgue measure of a point is 0, so even though a value for the PDF exists at that point, the probability is 0.
We don't run into issues here mathematically because we are on a continuous interval.
### The Normal Distribution
Likely the most famous continuous distribution, the normal distribution is given by the famous "bell curve." In this case, the sample space is the entire real line. The probability that a normally distributed random variable $X$ lies between any two points $a$ and $b$ is given by $$P(a\leq X \leq b) = \int_{a}^{b}\frac{1}{\sqrt{2\pi\sigma^{2}}}\exp\left(-\frac{(x-\mu)^{2}}{2\sigma^{2}}\right)dx$$ where $\mu$ is the mean and $\sigma^{2}$ is the variance.
## Singular Continuous Distributions
We're going to begin this section by discussing everyone's favorite counterexample in mathematics: the Cantor set.
### The Cantor set
The Cantor set is given by the limit of the following construction:
1. Take the interval $[0,1]$.
2. Remove the middle third: $(1/3, 2/3)$, so you're left with $[0,1/3]\cup[2/3,1]$
3. Remove the middle third of each of the remaining intervals. So you remove $(1/9,2/9)$ from $[0,1/3]$ and $(7/9,8/9)$ from $[2/3,1]$, leaving you with the set $[0,1/9]\cup[2/9,1/3]\cup[2/3,7/9]\cup[8/9,1]$
Continue this process infinitely.
This is an example of a set that is uncountable, yet has Lebesgue measure 0. Earlier, when we discussed Lebesgue measure, we noted that all countable sets had measure 0. Thus we may conclude that only uncountable sets (like intervals) have nonzero Lebesgue measure. However, the Cantor set illustrates that not all uncountable sets have positive Lebesgue measure. To see why the Cantor set has Lebesgue measure 0, we will look at the measure of the sets that are removed (the complement of the Cantor set):
At the first step, we have removed one interval of size 1/3. At the second step, we remove two intervals of size 1/9. At the third step, we remove four intervals of size 1/27. Let's call $S_{n}$ the subset removed from the interval [0,1] by the $n$th step. By the end of the third step, we have removed a set of size $$m(S_{3}) = \frac{1}{3} + \frac{2}{3^{2}} + \frac{4}{3^{3}}$$ By the $n$th step, $$m(S_{n}) = \sum_{j=0}^{n}\frac{2^{j}}{3^{j+1}}$$ This is the partial sum of a geometric series, so $$m(S_{n}) = 1-\left(\frac{2}{3}\right)^{n}$$ Now, the Cantor set is formed when $n \to \infty$. The measure of the complement of the Cantor set, which we called $S_{\infty}$ then has measure $$m(S_{\infty}) = \lim_{n \to \infty}m(S_{n}) = \lim_{n \to \infty}1-\left(\frac{2}{3}\right)^{n} = 1$$ But the original interval we started with had Lebesgue measure 1, and the union of the Cantor set with its complement $S_{\infty}$ is the interval [0,1]. That means that the measure of the Cantor set plus the measure of its complement must add to 1, which implies that the Cantor set is of measure 0. However, since we removed open intervals during the construction, there must be something left; in fact, there are uncountably many points left.
Now we have an uncountable set of Lebesgue measure 0. We're going to use this set to construct the only example I could find of a singular continuous distribution. It is very important that the Cantor set is an uncountable set of Lebesgue measure 0.
### Building the Cantor distribution
Update: Following a correction from an earlier version, I'm going to show how to construct this distribution directly and via the complement of the Cantor set. The latter was used in a textbook I found, and is a bit convoluted in its construction, but I'm going to leave it.
The direct construction is to look at the intervals left behind at each stage $n$ of constructing the Cantor set. Assign a probability mass of $\frac{1}{2^{n}}$ to each of the $2^{n}$ intervals left behind, and this is your distribution function. It's basically a continuous uniform distribution, but on stages of the Cantor set construction. Sending $n \to \infty$ yields the Cantor set, but the probability distribution moves to 0 on a set of measure 0. Thus, unlike the continuous uniform distribution, where the probability of any single point was 0, but the support has positive measure, we essentially have the continuous uniform distribution occurring on a set of measure 0, which means we have a continuous distribution function on a singular support of measure 0 that is uncountable and thus not discrete. This distribution is therefore neither continuous nor discrete.
Another way to construct this is by complement,via Kai Lai Chung's A Course in Probability Theory. (Note: after a second glance at this, I found this to be a relatively convoluted way of constructing this distribution, since it can be fairly easily constructed directly. However, I imagine the author's purpose was to be very rigid and formal to cover all his bases, so I present a review of it here:) Let's go back to the construction of the Cantor set. At each step $n$ we have removed in total $2^{n}-1$ disjoint intervals. Let's number those intervals, going from left to right as $J_{n,k}$, where $k = 1,2,\ldots, 2^{n}-1$. For example, at $n=2$ we have that $J_{2,1} = (1/9,2/9)$,$J_{2,2} = (1/3,2/3)$, and $J_{2,3} = (7/9,8/9)$. Now let the quantity $c_{n,k} = \frac{k}{2^{n}}$. This will be the probability mass assigned to interval $J_{n,k}$. So we define the distribution function as $$F(x) = c_{n,k}, x \in J_{n,k}$$
Let $U_{n} = \cup_{k=1}^{2^{n}-1}J_{n,k}$, and $U = \lim_{n\to\infty}U_{n}$ The function $F$ is indeed a distribution function and can be shown to be uniformly continuous on the set $D = (-\infty,0)\cup U \cup (1,\infty)$. However, none of the points in $D$ is in the support of $F$, so the support of $F$ is contained in the Cantor set (and in fact is the Cantor set). The support (the Cantor set) has measure 0, so it is singular, but the distribution function is continuous, so it cannot be a discrete distribution. This distribution fits nowhere in our previous two classes, so we must now create a third class -- the singular continuous distribution.
(By the way, even though the PDF doesn't exist, the Cantor distribution still has mean of 1/2 and a variance of 1/8, but no mode. It does have a moment generating function.)
## Any other examples?
With some help, I spent some time poring through quite a few probability books to seek further study and other treatment of singular continuous distributions. Most said absolutely nothing at all, as if the class didn't exist.
One book,Modern Probability Theory and Its Applications has a rather grumpy approach:
There also exists another kind of continuous distribution function, called singular continuous, whose derivative vanishes at almost all points. This is a somewhat difficult notion to picture, and examples have been constructed only by means of fairly involved analytic operations. From a practical point of view, one may act as if singular continuous distribution functions do not exist, since examples of these functions are rarely, if ever, encountered in practice.
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Pick the right output capacitors for LED drivers
Posted: 01 Apr 2008 ?? ?Print Version ?
Keywords:LED? LED array? output capacitor? white LED?
By John Betten
Texas Instruments
Driving an LED or LED array is not without its challenges. The LEDs require a well-designed constant-current source for controlled brightness. More specifically, the output capacitor in the traditional buck converter that serves to drive the LEDs can have a significant effect on control-loop characteristics, and the capacitor type as well as the output circuit configuration is often critical.
Placing the capacitor in parallel with the LEDs, vs. from output to ground, for example, can make the difference between using the simpler type-two compensation circuit and a type-three circuit for reduced parts count, a more linear and stable loop transfer function, and ease in design.
Ultimately, output capacitor sizing and type is determined by what is best for the intended application and there are several options. The output capacitor can be ceramic or aluminum; sometimes the designer may choose to omit the output capacitor entirely. SPICE circuit modeling provides a good way to validate and confirm the design.
LED design
The use of LEDs in automotive and outdoor lighting applications and the like has grown substantially, largely due to the availability of more efficient, white high-power devices. Luminous efficacies of greater than 175 lumens/W in white LEDs are now commercially available. Operational lifetimes of greater than 50,000hrs and compact size are driving their increased usage.
An LED has a forward V-I characteristic curve that is similar to a diode. Below the LED turn-on threshold, which for a white LED is approximately 3.5V, very little current will flow through it. Above that threshold, current flow increases rapidly for incremental increases in forward voltage. The rise in current is exponential. Thus, the LED can be accurately modeled in SPICE, for a given operating current, as a voltage source in series with a resistor. That is, for accurate modeling the resistor's value depends on the amount of current flowing through the LED. Figure 1 shows the measured impedance of a 1W white LED. The slope of the LED's V-I curve essentially represents the LED's dynamic impedance as a function of the load current.
A 1W LED illuminates at currents as low as 1mA, although not very brightly. At large forward currents, the LED operates at a high power level, which in turn begins to heat the die. As a result, the LED's forward drop increases, as does its dynamic impedance. It is critical to consider the thermal environment when the LED's impedance is determined.
Modeling the converter
The LED's driving source must be designed very carefully. Consider, for example, the voltage-mode buck converter in Figure 2 using the TPS40200 controller, with the converter designed to drive three series LEDs at a constant current of 1A. It regulates the voltage across the current sense resistor (R8) at a constant 0.7V. In essence, R8 programs the current regulated in the LED string.
The output from the converter is equal to the voltage across the LED string, plus the reference voltage (0.7V). For three white LEDs, the output is approximately (3.5)(3) + 0.7 = 11.2V. In a typical buck converter, the output capacitor (C8) is connected from the output-to-ground. However, in this circuit the output capacitor is connected across the LEDs. Although this may seem like a minor difference, it greatly simplifies stabilizing the control loop.
Figure 3: SPICE model for LED buck converter.
Figure 3 shows the SPICE model of the AC control loop. The modulator "gain" block is internally set to a fixed gain of 8V/V (minimum), as programmed by the TPS40200 controller. This gain is constant over input voltage due to the voltage feed-forward feature of the controller, which changes the oscillator ramp amplitude in proportion to any input voltage variations. From Figure 1, the dynamic impedance of a single LED driven with 1A is 0.5?. Three LEDs are modeled as a lump sum of three series 0.5? resistors and three series 3.5V sources. Note that the resultant 10.5V DC source has no effect on the AC control loop model (SPICE shorts out all DC voltage sources in AC loop analyses). To measure the closed loop gain and phase margin, we break the feedback path and insert an AC voltage source (Vac) at the current regulation point (R8).
Simulation with ceramic capacitor across LEDs
Figure 4 shows the results of the AC simulation in terms of total loop gain, phase response, and the power stage's voltage gain (defined as the sum of the modulator's fixed "gain" block of eight (i.e., 18dB) and the output filter response. This control-to-output gain is a measure of the full loop gain minus the error amplifier gain and is equal to Vo/Vea out.
The power stage gain starts out flat at 7.5dB and rolls off with a slope of -1 (i.e., -20dB/decade) at 3.7kHz. At frequencies below the single-order pole at 3.7kHz, the gain is equal to R8/ (R8 + RLED + RL1) multiplied by the "gain" block. The inductor resistance (RL1) is small relative to the other terms, and does not affect the overall transfer function much. The frequency of the pole in the power stage gain is
The actual measured gain and phase plots for the circuit modeled in Figure 2 is shown in Figure 5.
Figure 5: Measured transfer functions, ceramic output capacitor across LED.
With a loop gain of 26KHz and 77 phase margin, the measured response correlates well with the simulated response.
So why isn't the output capacitor a factor in the above equation? At frequencies above the pole, the impedance of C8 is large relative to the lower impedances of RLED and R8, allowing those two terms to dominate. At these higher frequencies, the impedance of L1 is large and forms a voltage divider with RLED and R8. A zero occurs at
The frequency of the zero is where the impedance of capacitor C8 is equal to the sum of the LED's impedance and the capacitor's ESR. Normally this would cause the power stage gain to flatten out from its slope of -1. This does not happen because C8 is "shorting out" only a portion of the impedance at the output and the increasing impedance of L1 dominates the filter response. C8 essentially has no impact on the filter's response when the value of C8 is small (where the boundary condition for C8 is met). For large values of C8, the zero it introduces becomes noticeable at a frequency lower than the pole of the power stage gain. If the value of C8 is equal to the boundary condition in the first equation, the zero frequency of the first equation and the pole frequency in the second equation are equal.
Simulation with a large aluminum capacitor
Now we replace the output capacitor in the simulation circuit with a large aluminum electrolytic capacitor (Figure 6).
Figure 6: SPICE model, large aluminum capacitor across LED.
The ESR is significantly larger than that of a ceramic capacitor. The capacitance value is selected to demonstrate the change in the loop transfer functions when the zero from the second equation is placed at a frequency lower than the pole frequency in the first equation.
As seen in Figure 7, a low-frequency zero causes an increase in gain, but ultimately the gain is limited to 18dB by the "gain" block in Figure 3. Above this zero frequency, a low-frequency pole begins to decrease the gain at a frequency determined by
Thus, the pole is shifted slightly lower in frequency than indicated by the first equation. The above equation is an approximation based on a large capacitance, where the ESR dominates C8's capacitive reactance at the pole frequency. Essentially, the ESR is in parallel with the LED impedance. At higher frequencies, the gain rolls off at a slope of -1, similar to the response shown previously for the smaller value of C8.
To compensate the loop gain for this given power stage gain, the zero of the type-two compensation circuit should be located near the pole frequency in the equation above. Once the loop is properly compensated, the size of C8 has little difference in the overall loop gain and phase margin. The choice of capacitor value and type is up to the designer, and the choice impacts the ripple current in the LED.
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https://infoscience.epfl.ch/record/135642
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Infoscience
Thesis
# Ground state properties of large atoms and quantum dots
We investigate the ground state properties of large atoms and quantum dots described by a d-dimensional N-body Hamiltonian of confinement ZV. In atoms, d = 3 and V is the Coulomb interaction; in dots, d = 2 and V is phenomenologically determined. We express the grand-canonical partition function in a path integral approach, and evaluate its expansion in Z-1. The problem can be seen as that of field theory possessing a saddle point. This saddle point results in a mean-field contribution to the energy, while the fluctuations result in the correlation energy. The mean-field contribution to the energy is self-consistently determined by the Hartree potential and contains an exchange term. Its smooth contribution is evaluated by a semiclassical method, with ε = Z-1/d in the role of ℏ, while its oscillating contribution can be related to the periodic orbits in the corresponding classical Hamiltonian. In the case of atoms, the leading order in ε of the correlation energy contains a term in Z ln Z1/3, which is essential in reproducing the behaviour shown by reference values, and a term in Z. While we have evaluated the contribution to the Z-term provided by the leading fluctuation order, the numerical evaluation of the contributions provided by higher order fluctuations remains an open problem. The self-consistent contribution to the energy corresponds to the statistical atom, composed of Thomas-Fermi and its corrections, comprehensively analysed, including oscillations, by Schwinger and Englert. In the case of dots, the leading order in ε of the correlation energy is a universal contribution of order Z, which we obtain in closed form. We then determine the expansion in ε of the smooth contributions down to this correlation order. We apply the approach to dots of quadratic and quartic confinement, including the oscillating contribution in the case of a chaotic quartic confinement.
Thèse École polytechnique fédérale de Lausanne EPFL, n° 4406 (2009)
Programme doctoral Physique
Faculté des sciences de base
Institut de théories des phénomènes physiques
Groupe de chaos et désordre
#### Reference
Record created on 2009-04-06, modified on 2016-08-08
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http://www.statsblogs.com/author/honglang-wang/
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Blog Archives
Welcome to my Homepage
July 10, 2014
By
My academic homepage just has been launched. Welcome to visit: Honglang Wang’s Homepage.
Useful for referring—2-25-2014
February 25, 2014
By
Interview with Nick Chamandy, statistician at Google You and Your Research + video Trustworthy Online Controlled Experiments: Five Puzzling Outcomes Explained A Survival Guide to Starting and Finishing a PhD Six Rules For Wearing Suits For Beginners Why I Created C++ More advice to scientists on blogging Software engineering practices for graduate students Statistics Matter […]
Useful for referring—2-25-2014
February 25, 2014
By
Interview with Nick Chamandy, statistician at Google You and Your Research + video Trustworthy Online Controlled Experiments: Five Puzzling Outcomes Explained A Survival Guide to Starting and Finishing a PhD Six Rules For Wearing Suits For Beginners Why I Created C++ More advice to scientists on blogging Software engineering practices for graduate students Statistics Matter […]
JSM2013
July 31, 2013
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This post is for JSM2013. I will put useful links here and I will update this post during the meeting. Big Data Sessions at JSM Nate Silver addresses assembled statisticians at this year’s JSM Data scientist is just a sexed up word for statistician What I have learned from this meeting (Key words of this […]
JSM2013
July 31, 2013
By
This post is for JSM2013. I will put useful links here and I will update this post during the meeting. Big Data Sessions at JSM Nate Silver addresses assembled statisticians at this year’s JSM Data scientist is just a sexed up word for statistician What I have learned from this meeting (Key words of this […]
A common theme in mathematics
April 2, 2013
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$A common theme in mathematics$
This is from a post Connected objects and a reconstruction theorem: A common theme in mathematics is to replace the study of an object with the study of some category that can be built from that object. For example, we can replace the study of a group with the study of its category of linear representations, […]
A common theme in mathematics
April 2, 2013
By
$A common theme in mathematics$
This is from a post Connected objects and a reconstruction theorem: A common theme in mathematics is to replace the study of an object with the study of some category that can be built from that object. For example, we can replace the study of a group with the study of its category of linear representations, […]
Think about statistical inferences from the ground up again
March 3, 2013
By
The evidence in large medical data sets is direct, but indirect as well – and there is just too much of the indirect evidence to ignore. If you want to prove that your drug of choice is good or bad your evidence is not just how it does, it is also how all the other drugs […]
Think about statistical inferences from the ground up again
March 3, 2013
By
The evidence in large medical data sets is direct, but indirect as well – and there is just too much of the indirect evidence to ignore. If you want to prove that your drug of choice is good or bad your evidence is not just how it does, it is also how all the other drugs […]
Useful for referring–1-20-2013
January 20, 2013
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Machine Learning, Big Data, Deep Learning, Data Mining, Statistics, Decision & Risk Analysis, Probability, Fuzzy Logic FAQ A Funny Thing Happened on the Way to Academia . . . Advice for students on the academic job market (2013 edition) Perspective: “Why C++ Is Not ‘Back’” Is Fourier analysis a special case of representation theory or […]
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https://www.physicsforums.com/threads/whats-the-meaning-of-the-cartesian-coordinates-of-the-atom.106327/
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# Homework Help: What's the meaning of the Cartesian coordinates of the atom?
1. Jan 10, 2006
### zsglly
How to get the Cartesian coordinates of an atom?
Dear friends,
Such a question confused me when reading!
"xi,yi and zi are the Cartesian coordinates of the ith atom"
How to get the coordinate of an atom? For example: carbon, oxygen?
I think the atom is only a dot! What's the way to indicate it with Cartesian coordinate?
Thank you!!
Sincerely,
zsglly
Last edited: Jan 10, 2006
2. Jan 10, 2006
### lightgrav
They're telling you the coordinate of the atom's center-of-mass
(we always describe the location of an object by its c.o.m. location!).
The C atom is at ( x_c , y_c , z_c ) ; the O atom is at ( x_o , y_o , z_o ) .
3. Jan 10, 2006
### zsglly
But I need the specific numerical value for calculating.
How to get it?
4. Jan 10, 2006
### lightgrav
Well, if they're not given in the problem, choose:
a) the text might list some inter-atom spacings in the chapter
b) you're supposed to keep them as variables (x,y,z)
What are you supposed to be calculating / computing ?
5. Jan 10, 2006
### zsglly
Until now, I didn't find any text about inter-atom spacings
To calculate moments of inertia.
I only want to get the value of several atoms.
Last edited: Jan 10, 2006
6. Jan 11, 2006
### zsglly
Actually, I'm not sure whether I need calculate the Cartesian coordinates or not. But I hope not. Because my only intention is to get the value of carbon, oxygen and so on.
7. Jan 11, 2006
### Gokul43201
Staff Emeritus
Of what ??? ( For instance, a carbon dioxide molecule about an axis perpendicular to the molecular axis ?) Please write down the given question completely. You have not provided enough information.
8. Jan 11, 2006
### algebra_chem
are you trying to say something like:
how many atoms does a carbon or oxygen have????
9. Jan 28, 2006
### zsglly
To calulate the moment of inertia using J.O. Hirshfelder's method
Do you know?
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https://zbmath.org/?q=an:0924.41001
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×
# zbMATH — the first resource for mathematics
Korovkin-type approximation theory and its applications. (English) Zbl 0924.41001
de Gruyter Studies in Mathematics. 17. Berlin: Walter de Gruyter. xi, 627 p. (1994).
In 1953 P. P. Korovkin discovered a criterion in order to decide whether a given sequence $$(L_n)$$ of positive linear operators on the space $$C[0,1]$$ is an approximation process, i.e., $$L_nf\to f$$ uniformly on [0,1] for every $$f\in C[0,1]$$: in fact, it is sufficient to verify that $$L_nf\to f$$ only for $$f\in \{1,x,x^2\}$$.
This result has been extended to other function spaces and to abstract spaces. Now the Korovkin approximation theory (KAT) has fruitful connections with functional analysis (notably with Choquet’s theory and Banach algebras theory), harmonic analysis, measure and probability theory, partial differential equations; an important feature of this monograph is the systematic presentation of all these connections.
The book is addressed to specialists in the above mentioned fields; a large part of it can also serve as a textbook for a graduate-level course. The authors have contributed significantly to the development of this theory. They give a survey on classical as well as recent developments in the field. Most of the results appear in book form for the first time.
In order to make the exposition self-contained, the prerequisites (from topology and analysis, measure and probability theory, locally convex spaces and Choquet’s integral representation theory, semigroups of operators) are collected in Chapter 1. Chapters 2, 3 and 4 are devoted to the main aspects of KAT in $$C_0(X)$$ $$(X$$ locally compact) and $$C(X)$$ $$(X$$ compact). The fundamental problem consists in studying, for a given positive linear operator $$T:C_0(X)\to C_0(Y)$$, those subspaces $$H$$ of $$C_0(X)$$ (if any) which have the property that every equicontinuous net of positive linear operators (or positive contractions) from $$C_0(X)$$ into $$C_0(Y)$$ converges strongly to $$T$$ whenever it converges to $$T$$ on $$H$$. (Such subspaces are called Korovkin subspaces for $$T$$). The classical case when $$T$$ is the identity operator is discussed in Chapter 4, where the authors present also the strong interplay between KAT and Choquet’s integral representation theory, as well as Stone-Weierstrass-type theorems. Furthermore, the existence of finite dimensional Korovkin subspaces is carefully analysed. The Korovkin subspaces for arbitrary positive linear operators, positive projections and finitely defined operators are characterized in Chapter 3. Here we find also applications to potential theory, Bauer simplices and Chebyshev systems. The results contained in Chapters 3 and 4 are based on the general Korovkin-type theorems for “bounded positive Radon measures, presented in Chapter 2 in connection with the theory of Choquet boundaries. Chapter 5 contains applications to the approximation of continuous functions defined on real intervals, by means of various kinds of operators. The rates of convergence are described by using classical moduli of continuity.
Chapter 6 contains a detailed analysis of some sequences $$(B_n)$$ of positive linear operators that have been studied recently; they connect the theory of $$C_0$$-semigroups of operators, partial differential equations and Markov processes. The operators $$B_n$$ are constructed by means of a positive projection $$T$$ acting on the space of continuous functions on a convex compact set $$K$$. This general construction has been proposed by F. Altomare [Ann. Sc. Norm. Sup. Pisa, Cl. Sci., IV. Ser. 16, No. 2, 259-279 (1989; Zbl 0706.47022]. By specializing $$K$$ and $$T$$ some well-known approximation processes can be obtained; new approximation processes (e.g., in the context of the infinite-dimensional Bauer simplices) are described and investigated.
The approximation properties of the operators $$B_n$$, their monotonicity properties and the preservation of some global smoothness properties are carefully analysed. Then a Feller semigroup is constructed in terms of powers of $$B_n$$. The infinitesimal generator of this semigroup is explicitly determined in a core of its domain; in the finite dimensional case it is an elliptic second-order differential operator which degenerates on the Choquet boundary of the range of $$T$$.
This theory is used to derive a representation and some qualitative properties of the solutions of the Cauchy problems which correspond to the involved diffusion equations. The transition function and the asymptotic behavior of the Markov processes governed by these diffusion equations are also described.
After the publication of the book, the theory presented in Chapter 6 has been further developed; see , e.g., [M. Campiti, G. Metafune, J. Approximation Theory 87, No. 3, 243-269 (1996; Zbl 0865.41027) and ibid., 270-290 (1996; Zbl 0874.41010)], [F. Altomare, I. Carbone, J. Math. Anal. Appl. 213, No. 1, 308-333 (1997; Zbl 0894.35044)], [F. Altomare, A. Attalienti, Math. Z. 225, No. 2, 211-229 (1997; Zbl 0871.41016)], [A. Favini, J. A. Goldstein, S. Romanelli, in: Stochastic processes and functional analysis, J. A. Goldstein, Marcel Dekker, New York, 1997, 85-100 (1997; Zbl 0889.35039)], [M. Romito, Mh. Math. (to appear)], [F. Altomare and the reviewer, Atti Semin. Mat. Fis. Univ. Modena 46, Suppl. 13-38 (1998; Zbl 0917.35042)].
In two appendices, written by M. Pannenberg and F. Beckhoff respectively, the main developments of KAT in the setting of Banach algebras are outlined.
The book contains also a subject classification, a symbol index and a subject index, all of them very useful. The historical notes and the references are very detailed. Well written and well produced, this comprehensive research monograph is a timely and welcome addition to the mathematical literature.
##### MSC:
41-02 Research exposition (monographs, survey articles) pertaining to approximations and expansions 41A36 Approximation by positive operators 41A25 Rate of convergence, degree of approximation 41A35 Approximation by operators (in particular, by integral operators) 41A63 Multidimensional problems (should also be assigned at least one other classification number from Section 41-XX)
##### Keywords:
Korovkin approximation theory
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https://physics.stackexchange.com/questions/709069/what-does-it-mean-if-the-fermi-level-crosses-into-the-valence-band-how-about-in
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# What does it mean if the Fermi level crosses into the valence band? How about into the conduction band?
I've been working on this material to get more accustomed to Quantum Espresso, and I've gone on and performed calculations to get their band structures. Here are the band structures that I got for two of the variations of my material:
Used EV-GGA to get these band structures, I could have used others, but I'm just curious as to what these particular band structures imply. As you can see, for the first one, the Fermi level has crossed into the valence band while for the second one the Fermi level is in the conduction band. Do these both imply metallic nature? These are undoped materials, can doping possibly cause the Fermi levels to move accordingly and make these materials semiconductors? Thank you everyone for your help.
The terms "conduction band" and "valence band" sort of lose their usefulness if you are not talking about a standard band insulator where you have a filled valence band and the chemical potential lies in the gap.
In your two cases, both materials will be metallic because there is finite density of states at the Fermi level.
Yes with doping you can move the Fermi level. Electron doping will move the Fermi level up and hole doping will move it down. But in the actual real(physical) material it may not be possible to dope it sufficiently to put the Fermi level within the gap.
• Thank you so much for your answer. The doping thing may be a good avenue for further study because I'm also curious about how the location of the Fermi level changes with doping. I'd like to ask about what you what you said about the finite density of states. Would much denser bands around the Fermi level imply some other characteristic for the material? May 17 at 7:43
• It depends on what you mean by "denser bands". If you mean more bands, then that will affect what your Fermi surface looks like. For example, In both of your cases multiple bands cross the Fermi level, so you will have fairly complicated Fermi surfaces with multiple hole and electron pockets. This will certainly affect the material properties, such as the conductivity tensor. If you mean tuning the density of states itself, that is related to the curvature of the bands and that will also affect the material in many ways, some simple like it will change the conductivity,
– pmal
May 17 at 7:54
• but also potentially in more complex ways because if you have a high density of states then the system will be more susceptible to collective instabilities like magnetism or superconductivity.
– pmal
May 17 at 7:54
• Thank you so much! You've given me a good place to start with how to rationalize these band structures. Do you have any good references that I could use to read more about this? May 17 at 8:07
• That is a bit hard to answer without knowing your background knowledge. If you are doing DFT calculations, I would think you have already read some standard solid state physics books? If not, Ashcroft and Mermin is a standard, and also Kittel. My favorite more modern condensed matter book is Girvin and Yang.
– pmal
May 17 at 8:11
In the book by Naeman, Semiconductor Physics, the equation $$E_F -E_{Fi}=kT\ln{\frac{n_0}{n_i}}$$ is derived and relates the change in the Fermi level due to doping. $$E_F$$ is the Fermi level after doping and $$E_{Fi}$$ is the intrinsic Fermi level, where $$n_0$$ and $$n_i$$ are the initial and final electron number densities before and after doping.
So the Fermi level clearly changes due to doping.
• Thank you for this! I will be looking into Naeman's book as well, thanks for giving me a reference. May 17 at 7:45
• That's ok. good luck with your studies. May 17 at 7:46
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https://physics.stackexchange.com/questions/453890/why-is-the-mainstream-theory-of-cosmological-redshift-inconsistent-with-the-main
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# Why is the mainstream theory of cosmological redshift inconsistent with the mainstream theory of gravitational redshift
Gravitational redshift
Cause : A reduction in the decompression of space* over distance (due to the presence of mass).
Mainstream theory: Photons are emitted in a region of higher gravity with Energy A, and received in a region of lower gravity with Energy A, where Energy A is lower than the Energy B that would have been emitted by a similar event in a region of lower gravity.
Evidence: There is plenty of experimental evidence to support this theory.
Cosmological redshift
Cause: A reduction in the decompression of space* over time (due to universal expansion).
Mainstream Theory: Photons were emitted in the distant past with Energy B and received in the present with lower Energy A, where B is the energy that would be emitted from a similar event in the present.
Evidence: No hard evidence that I am aware of. Some may argue that CMB was emitted as ultraviolet radiation and we now see it as microwave radiation. I agree, but if we are being consistent with the hard evidence we have about gravitational redshift, then we should expect that time is moving much more quickly today than it was when the CMB was emitted, just as it moves more quicky in regions of lower gravity. So yesterday's ultraviolet wave is today's microwave - with the same energy.
*I use the word space for brevity, but really mean the universal metric through which light travels.
As far as I can see, apart from their causes, the only difference between cosmological redshift and gravitational redshift is that one happens over space and the other happens over time. So why is the mainstream view on cosmological redshift inconsistent with the mainstream view on gravitational redshift, for which there is ample supporting evidence?
• Both of these effects can be computed in the same way from the same equation. It is true that, in the usual coordinate systems, one of them involves a change in $g_{tt}$ (temporal component) while the other involves a change in $g_{ii}$ (spatial component). – knzhou Jan 13 at 11:49
• Of course, you can change your coordinates so that both are due to $g_{tt}$, I suppose, or both due to $g_{ii}$, or really anything else. But it really doesn't matter. You can solve a problem in more than one coordinate system. So it is unclear what "inconsistency" you're referring to. – knzhou Jan 13 at 11:51
• @knzhou I'm referring to the difference I highlighted in bold. In the one case we say that the energy of the photon remained constant, in the other case we say it reduced. – Alan Gee Jan 13 at 15:44
• what you describe as redshift is not a shift, if the energy does not change. Do you have a link for the statement? – anna v Jan 13 at 15:53
• @anna v a shift in frequency is not necessarily an energy change if time is running faster, So my question can also be phrased as 'why do we think time dilation occurs due to gravity but not due to (opposite of)expansion?' – Alan Gee Jan 13 at 16:02
Consider a garden pond with evenly spaced pebbles across it.
A frog and a fish start out at one end and cross it. The frog with a constant hop rate across the pebbles, the fish at a constant swim speed. They reach the other side at the same time. In this static situation there is little to choose between the two creatures because they both get the same job done in the same time.
Now the owner of the pond decides to extend it a little, and after doing so, adjusts the spacing of the existing pebbles to make it look pretty again. The frog and the fish repeat their journey, and this time the frog gets to the other side first. That's because the frog had the same number of pebbles to hop, at a constant hop rate, while the fish had further to swim.
When Physicists analyse light from distant galaxies, they assume that it travelled through space and time like the fish through an expanding pond. Gravitational time dilation, on the other hand, indicates that it travels more like the frog.
I know that when light travels through space that has been warped by the presence of mass its speed varies accordingly. Yet I am expected to believe that when light passes through space that has been warped by universal expansion, its speed remains constant. Correct me if I'm wrong, but for me that smacks of inconsistency.
• If you would like to verify that the current paradigm is self-consistent, you're free to get any textbook on general relativity and verify the equations yourself. We're not hiding anything -- the book will even help you evaluate it. The problem, as I stated in the comments above, is that the math-free intuition one uses can be quite unreliable, changing depending on the reference frame. In practice, in GR physicists often calculate things rigorously first, and only afterward drape some intuitive words around the final result. – knzhou Feb 27 at 2:40
• @knzhou I am not basing anything on intuition. I am basing it on what I know about light, and I know a lot about light. I refuse to blindly accept things just because most people do. You are welcome to GR with all of its abstractions, I will focus on simple truths. – Alan Gee Feb 27 at 8:04
• And from where did you get that information about light? Light is quite unintuitive. Electrical engineers can spend a lifetime studying its subtleties. And you're sure you know everything about it without even knowing any of the math? – knzhou Feb 27 at 11:23
• What I do know is, that by stubbornly insisting that the speed of light can never vary, you are hiding the majority of the meaning of $$E = mc^2$$ which as far as I am concerned is like self inflicted harm. It will probably take someone with far more clout than me to convince people of this, but it will happen. – Alan Gee Feb 27 at 18:20
• What are you actually proposing? If you're proposing an alternative theory that makes alternative predictions, go find out what they are, and make sure they're not already observed to be false. If you're proposing a different way of looking at the same theory, nobody really cares unless you can explain why your way is more useful. Right now you are saying that you really really really like one particular classical fact, and will take any interpretation that preserves it at the cost of ruining everything else. You can choose to do that but you can't choose to make others do it. – knzhou Feb 27 at 18:44
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http://link.springer.com/article/10.1007%2Fs00396-012-2850-4
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, Volume 291, Issue 5, pp 1201-1210
Date: 17 Nov 2012
# Colloidal crystallization of cationic gel spheres of lightly cross-linked poly(2-vinylpyridine) in the deionized aqueous suspension
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## Abstract
Colloidal crystallization of deionized suspensions of the cationic gel spheres of lightly cross-linked poly(2-vinylpyridine) (PEGMA-P2VP) has been studied from the microscopic observation, morphology, phase diagram, and elastic property. Critical concentrations of melting coexisted with ion-exchange resins were low compared with those without resins and increased but slightly as the degree of cross-linking decreased. The densities of the gel spheres, i.e., weight percent of the gel spheres divided by the corresponding volume percent, were between 0.7 and 0.9 and rather insensitive to the degree of cross-linking of the spheres examined from 0.1 to 1 mol%. This means that the gel spheres are rather dense. The closest inter-sphere distances of the crystals were much longer than the hydrodynamic diameters of the gel spheres especially at low sphere concentrations. Fluctuation parameters evaluated from the rigidities of the crystals of PEGMA-P2VP were similar to those of colloidal crystals of typical hard spheres. Mono-layered adsorption of cationic gel spheres at the nearest-neighbored layer from a cover glass of the cell was observed microscopically. The stable ordered layers, however, formed beyond the monolayer in the suspension phase. These experimental findings support the important role of the extended electrical double layers around the cationic gel spheres in addition to the excluded volume effect of the sphere themselves on the crystallization.
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https://www.computer.org/csdl/trans/tp/2007/07/i1165-abs.html
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Issue No. 07 - July (2007 vol. 29)
ISSN: 0162-8828
pp: 1165-1179
Tom? Werner , IEEE Computer Society
ABSTRACT
The max-sum labeling problem, defined as maximizing a sum of binary (i.e., pairwise) functions of discrete variables, is a general NP-hard optimization problem with many applications, such as computing the MAP configuration of a Markov random field. We review a not widely known approach to the problem, developed by Ukrainian researchers Schlesinger et al. in 1976, and show how it contributes to recent results, most importantly, those on the convex combination of trees and tree-reweighted max-product. In particular, we review Schlesinger et al.'s upper bound on the max-sum criterion, its minimization by equivalent transformations, its relation to the constraint satisfaction problem, the fact that this minimization is dual to a linear programming relaxation of the original problem, and the three kinds of consistency necessary for optimality of the upper bound. We revisit problems with Boolean variables and supermodular problems. We describe two algorithms for decreasing the upper bound. We present an example application for structural image analysis.
INDEX TERMS
Markov random fields, undirected graphical models, constraint satisfaction, belief propagation, linear programming relaxation, max-sum, max-plus, max-product, supermodular optimization.
CITATION
T. Werner, "A Linear Programming Approach to Max-Sum Problem: A Review," in IEEE Transactions on Pattern Analysis & Machine Intelligence, vol. 29, no. , pp. 1165-1179, 2007.
doi:10.1109/TPAMI.2007.1036
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https://www.physicsforums.com/threads/physics-speed-mph-question.56502/
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# Physics speed mph question
1. Dec 12, 2004
I thought the answer was 90mph, but my friend says it's wrong. I just can't figure out any other answer.
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You drive to the store which is a 2 mile trip. In the first mile you average 30 mph, how fast must you drive the second mile in order to average 60mph for the entire 2 mile trip?
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thnx
Jennifer
2. Dec 12, 2004
### Zurtex
I would have thought it would have been an average 90mph in the 2nd mile as well
3. Dec 12, 2004
Nobody?
4. Dec 12, 2004
### master_coda
If your average speed for the trip were 60 mph, it would take you 2 minutes to complete the entire trip. Thus you have to drive fast enough on the second leg to complete the trip in 2 minutes.
However if you only drive at 30 mph for the first mile then it you will already have taken 2 minutes; no matter how fast you drive for the second mile, you'll take longer than 2 minutes so you can't actually average 60 mph for the whole trip.
Note that this is because "average speed = distance travelled / travel time" and not the average of all the speeds over each segment.
5. Dec 12, 2004
thnx! That makes sense! :)
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https://www.physicsforums.com/threads/help-with-poisson-equation.315876/
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# Help with Poisson equation
1. May 23, 2009
### zebra
1. The problem statement, all variables and given/known data
Hi, I am looking for a hint, how to solve the following Dirichlet problem. All the standard textbooks have only examples for Dirichlet problems in rectangular or polar coordinate systems, but this problem is defined for a parabolic region.
2. Relevant equations
uxx+uyy=2, x>y2
u(x,y)=0, x=y2
3. The attempt at a solution
Transformation into parabolic coordinates and using separation of variables? I am having a problem even with that. The parabolic coordinates with the parabolic Laplacian are here http://eom.springer.de/P/p071170.htm. I don´t even know, how to transform the boundaries. The parabolic coordinates are so unusual. Is this a right method or would you solve it differently? (with Green functions, or Laplace transform etc)
Can you offer guidance or do you also need help?
Draft saved Draft deleted
Similar Discussions: Help with Poisson equation
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http://quantumfrontiers.com/2012/12/03/is-alice-burning-the-black-hole-firewall-controversy/
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# Is Alice burning? The black hole firewall controversy
Quantum correlations are monogamous. Bob can be highly entangled with Alice or with Carrie, but not both.
Back in the early 1990s, I was very interested in the quantum physics of black holes and devoted much of my research effort to thinking about how black holes process quantum information. That effort may have prepared me to appreciate Peter Shor’s spectacular breakthrough — the discovery of a quantum algorithm for factoring intergers efficiently. I told the story here of how I secretly struggled to understand Shor’s algorithm while attending a workshop on black holes in 1994.
Since the mid-1990s, quantum information has been the main focus of my research. I hope that some of the work I’ve done can help to hasten the onset of a new era in which quantum computers are used routinely to perform super-classical tasks. But I have always had another motivation for working on quantum information science — a conviction that insights gained by thinking about quantum computation can illuminate deep issues in other areas of physics, especially quantum condensed matter and quantum gravity. In recent years quantum information concepts have begun penetrating into other fields, and I expect that trend to continue.
The study of quantum black holes has continued to be a very active and fruitful research area in recent years. I’ve not been much involved myself, though, except for one foray (well, also this one). But my friend Lenny Susskind encouraged me to attend a workshop on black holes at Stanford this past weekend, and I’m glad I did. It was fun, and it was gratifying to see that quantum information concepts were prominently featured in many of the talks.
The goal of the workshop was to clarify a question raised in this paper by Almheiri, Marolf, Polchinski, and Sully (AMPS): if a black hole is highly entangled with its surroundings, does a freely falling observer who crosses the event horizon burn to a crisp immediately right at the horizon. We have always believed that if Alice foolishly enters a black hole she will be just fine for a while, but will gradually encounter stronger and stronger gravitational forces which will eventually tear her to pieces. AMPS argued that under the right circumstances, Alice’s horrible death comes much earlier than expected, and without any warning. Joe Polchinski wrote a nice explanation of the AMPS argument over at Cosmic Variance, but I’ll give my own version here.
To understand the AMPS puzzle, one needs to appreciate that quantum correlations are different than classical correlations. Classical correlations can be “polygamous” while quantum correlations are “monogamous.”
If Alice and Bob both have copies of the same newspaper, then Alice and Bob become correlated because both can access the same information. But Carrie can acquire a copy of that same newspaper; Bob’s correlation with Alice does not prevent him from becoming just as strongly correlated with Carrie. For that matter, anyone else can buy a newspaper to join the party.
A quantum newspaper is different, because you can read it in two (or more) complementary ways, and we say that two newspapers are “maximally entangled” (have the strongest possible quantum correlations) if both newspapers have the same content when both are read in the same way. In that case, if Alice reads her paper held right-side up she finds only random gibberish, but if Bob reads his newspaper right-side up he sees exactly the same gibberish as Alice. If on the other hand Alice had chosen to read the paper turned sideways, she would have found some other random gibberish, but again Bob would see the same gibberish as Alice if he read his paper sideways, too. Because there is just one way to read a classical newspaper, and lots of ways to read a quantum newspaper, the quantum correlations are stronger than classical ones.
So strong, in fact, that Bob’s entanglement with Alice limits his ability to entangle with Carrie. Bob’s entropy S(B), a measure of his capacity to entangle with others, is an upper bound on the sum of Bob’s entanglement E(A,B) with Alice and his entanglement E(B,C) with Carrie. If Bob is highly entangled with Alice then he can entangle with Carrie only by sacrificing some of his entanglement with Alice. That’s why we say that entanglement is monogamous.
Following AMPS, imagine a black hole which is maximally entangled with another quantum system C outside the black hole. Like any black hole, this one evaporates by emitting Hawking radiation. Also following AMPS, assume that the evaporation is unitary, i.e., conserves quantum information. There is strong evidence that unitarity is an inviolable principle of physics, and we don’t really know how to make sense of quantum mechanics without it. Unitarity implies that as a system B is emitted by the black hole in the form of Hawking radiation, this system B, like the black hole from which it emerged, must be maximally entanged with C. And monogamy of entanglement means that B cannot be entangled with anything else besides C.
But this spells trouble for Alice, the brave soul who dares to fall into the black hole. If Alice’s passage through the event horizon were uneventful then she would fall though space that is nearly devoid of particles. But if we cut the empty space seen by Alice into the inside and outside of the black hole at the event horizon, then the particles in system B seen by an observer who stays outside are paired with particles on the inside — B is entangled with a system A inside the horizon, violating the monogamy of entanglement. Something’s wrong.
The AMPS proposal is that what Alice encounters at the horizon does not look like empty space at all — rather B and A are unentangled, which means that Alice sees many energetic particles. Monogamy of entanglement is rescued, but not poor Alice. She is incinerated by an intense wall of fire as she attempts to pass through the event horizon.
If a black hole forms from a collapsing star and then radiates for a long, long, long time until it has shed more than half its initial entropy, we expect the black hole to become maximally entangled with the radiation already emitted, and hence (if AMPS are right) for a firewall to appear. It is as though the singularity, which we expected to find deep inside the black hole, has crept right up to the event horizon when the black hole is very old.
Like many other physicists, I distrust this conclusion. The black hole could be very large, so that as Alice approaches the horizon she experiences only very weak tidal gravitational forces. It seems terribly unjust for Alice, unaware of the black hole’s age and with no indication that anything is amiss, to suddenly fry without any warning at all.
My first reaction to the AMPS paper was that we should think very carefully about whether, if there are no firewalls, the putative violation of monogamy of entanglement really has a clear operational meaning. We might be willing to tolerate polygamous entanglement if no observer can ever detect the crime! We must ask whether it is possible, at least in principle, for Alice to verify the entanglement between B and C, and then test the entanglement between B and A by plunging into the black hole. AMPS discuss this issue in their paper, but I don’t consider it to be settled. One consideration, mentioned at the workshop by both Patrick Hayden and Daniel Harlow, is that verifying the BC entanglement requires a quantum computation that might be infeasible as a matter of principle, at least for a large black hole.
For now, it seems appropriate to assume both information conservation and no firewalls, seeking some way of reconciling the two. This might involve truly radical revisions in the foundations of quantum mechanics, or bizarre nonlocal dynamics outside the black hole. If we are forced to accept that firewalls really exist, then we will need a deeper understanding of their dynamical origin than the indirect argument AMPS provided.
The workshop was invigorating because nearly everyone seemed confused. Paradoxes are always welcome in physics, as they can help to point us toward revolutionary advances. While no consensus has yet emerged about what the AMPS puzzle is teaching us, I’m hoping that the outcome will be a big stride forward in our understanding of quantum information in gravitational systems.
## 77 thoughts on “Is Alice burning? The black hole firewall controversy”
1. I was hoping you’d return from the workshop with a unified theory of everything… but an inspiring blog post is a decent consolation. Anyways, would you please clarify these sentences:
“Unitarity implies that as a system B is emitted by the black hole in the form of Hawking radiation, this system B, like the black hole from which it emerged, must be maximally entanged with C. And monogamy of entanglement means that B cannot be entangled with anything else besides C.”
In particular, is system B maximally entangled with BOTH C AND the black hole? Or is B only entangled with C at this point? If the latter, then doesn’t this mean that C needs to become less entangled with the black hole (due to monogamy?) Thanks!
2. I meant that B is only entangled with C. The crude picture is that initially the black hole is an n-qubit system, maximally entangled with the n-qubit system C. Then the black hole emits k qubits of Hawking radiation (system B), leaving behind an (n-k)-qubit black hole with reduced mass (call that system H). After B is emitted, both B and H are maximally entangled with subsystems of C, and not at all entangled with one another.
• Thanks for the reply! I asked the question because my neanderthal-level interpretation of Hawking radiation was as the creation of an entangled pair of virtual particles. One of which (negative energy) enters the black hole and the other (positive energy) escapes. I can’t reconcile this with your comment, so I think I need to revisit these concepts someday. Here is Hawking’s comment (and note of caution) which gave me this intuition (from “Particle Creation by Black Holes”):
“One might picture this negative energy flux in the following way. Just outside the event horizon there will be virtual pairs of particles, one with negative energy and one with positive energy. The negative particle is in a region which is classically forbidden but it can tunnel through the event horizon to the region inside the black hole where the Killing vector which represents time translations is spacelike. In this region the particle can exist as a real particle with a timelike momentum vector even though its energy relative to infinity as measured by the time translation Killing vector is negative. The other particle of the pair, having a positive energy, can escape to infinity where it constitutes a part of the thermal emission described above… …It should be emphasized that these pictures of the mechanism responsible for the thermal emission and area decrease are heuristic only and should not be taken too literally.”
• You’re right. The two pictures cannot be reconciled, and that is the AMPS puzzle. Hawking’s heuristic picture is a description of the entanglement between B and A that occurs in a state that looks like vacuum to the freely falling Alice. But AMPS say that if the black hole is maximally entangled with another system (as is the case for a sufficiently old black hole), then unitarity and monogamy imply that Hawking’s picture does not apply: B and A are not entangled. Therefore, the state is not such that freely falling Alice sees vacuum; she sees a firewall instead.
3. Could Susskind’s stretched horizon compromise be a misinterpretation of fecund universes, and thus, the problem is resolved?
4. Dear John, there are some really excellent papers-followups to AMPS which are much better than AMPS itself – a paper that is no good and that should only be praised for its provoking tone that led to a new wave of activity in these conceptual matters. The fresh Raju-Papadodimas paper is a real gem that clarifies many things. But most of the papers say pretty much the same thing and they conclude that the AMPS argument is flawed.
The briefest way to describe where your version of AMPS goes wrong is the assumption that Alice and Carrie are two distinct women. They’re not. They’re two sets of degrees of freedom expressed in two totally different bases, preferring two different sets of natural, local, coarse-grained observables (fields inside black hole; fields outside black hole) – but they carry the same information. More precisely, A is a subset of C in the usual “more inclusive” definitions of C. The black hole interior is correlated with some degrees of freedom in the exterior at the a priori Hilbert space level, so the maximal entanglement between A-B and B-C is really the same thing.
Raju and Papadodimas – two great students I knew from Harvard, now higher at the academic ladder – are extremely explicit in showing why the constraints allowing you to say that the interior is just a reshuffled exterior doesn’t cause any violations of nonlocality that could be measured by n-point functions with a finite n not scaling with the black hole size, and with accuracy worse than an exponentially fine one. The interior degrees of freedom are linked to an analytical continuation of some exterior ones but this relationship between them may only be decoded when one does some superfine experiments that are impossible in reality.
Some other anti-AMPS papers, such as the fuzzball-based ones, still say that Alice won’t burn but they say that the effective local theory will break down “somewhat earlier than you would like”. None of these statements is ever supported by waterproof arguments and Raju and Papadodimas actually show that a careful calculation shows that the effective field theory only breaks down in the most extreme conditions. I think that Raju and Papadodimas don’t really show that fuzzballs are wrong as a description – they just invalidate a qualitative conclusion that was associated with the fuzzball theory although it doesn’t follow from it.
Nomura and Varela wrote some papers that are simpler and more conceptual but I agree with them – and wrote the same things independently, see some of my texts (especially the end of the article “Raphael converts”)
http://motls.blogspot.com/search?q=black+hole+firewall&m=1&by-date=true
that Polchinski et al. seem to misunderstand some basic principles of quantum mechanics in this context, however unexpected I would find this statement about a prominent group led by a top theorist a decade ago. The problem is that AMPS assume that A and C “have to be” two independent sets of degrees of freedom – although the black hole complementarity has always been about the very statement that this independence is wrong. AMPS justify this independence by saying that before crossing the horizon, Alice may decide whether she will jump into the black hole or stay out, so she must have some “information in the wave function” that is ready to answer questions about her later measurements both inside and outside, according to her decision, and they assume that these must be two different subsets of the degrees of freedom describing the wave function.
But that’s just wrong. Depending on whether Alice decides to fall into the hole or stay out, the *same* degrees of freedom in the wave function she uses get interpreted in one (internal) way or another, completely different (external) way. Before her decision, her wave function is a linear superposition of two macroscopically different worlds (like in Schrodinger cat: most wave functions in the Hilbert space are these cat-like states!). In a part of the wave function, with some probability amplitudes and inclusive probability, she will jump inside; in another part, she stays out. These two basic terms in the wave functions are tensor multiplied by some wave functions of the “detailed degrees of freedom” but the composition of these “detailed degrees of freedom” (the natural way to describe them) differs in the two terms of the wave function, it depends on whether she jumps in or not (so it’s not strictly a tensor product; it’s a “fibration” of a sort). There’s nothing wrong about it because e.g. decoherence operates in a Hamiltonian- and state-dependent way. The preferred basis isn’t determined a priori; it emerges out of the dynamics that requires us to calculate how the Hamiltonian acts on the initial state. The Hamiltonian and initial state are needed to find out which observables “self-replicate” into the environmental degrees of freedom, and therefore become “classical-like” and able to define coarse-grained states. The myth (invalid consequence of a classical way of looking at the wave function) about the “a priori preferred bases” is the most widespread misunderstanding of quantum mechanics among physicists who are making far-reaching but wrong claims about QM and AMPS now belong to this set, too.
I think your blog entry is fair and balanced but, given the fact that I’ve considered you a top-ten world expert on black hole quantum information for years – although partly because of your bet victory against Hawking – I am disappointed by its being somewhat superficial and uncritical.
It’s people like Raju and Papadodimas whose work should be celebrated because they actually crack the formulae needed to learn how things may actually work and where are the actual limits of measurements that restrict locality – these local expectations only break down at the last possible moment, so to say, they show. It’s frustrating if even prominent physics bloggers such as you only promote the part of this research that is visible because it makes manifestly wrong claims.
All the best
Lubos
• I agree that regarding A to be a complementary description of the subsystem of C that is entangled with B would be a pleasing resolution of the puzzle. For that point of view to be consistent, there should be an obstruction that prevents any single observer from verifying both the AB entanglement and the BC entanglement. That’s what I had in mind when I said we should examine whether the violation of monogamy of entanglement has a clear operational meaning.
An older puzzle is that unitarity seems to imply that the same quantum information can be in two places on the same time slice (both encoded in the emitted Hawking radiation and behind the black hole horizon), a putative violation of the principle that quantum information cannot be cloned. That puzzle can be resolved by noting that there is a delay between when quantum information falls into the black hole and when it is released, so that by the time one copy of a quantum state is available in the Hawking radiation it is too late to verify that the other copy is still intact behind the horizon.
Resolving the AMPS puzzle seems to be trickier because there is no such delay, and Alice’s verification task is easy — she just falls through the horizon and either encounters a firewall or doesn’t. Still, I might feel satisfied by a compelling argument that a single observer can verify either the AB entanglement or the BC entanglement, but not both. I meant to say that in my post, but I wasn’t very clear.
• Dear John,
right, very true, there is an obstruction preventing an (one) observer from checking both entanglements at the same moment. At a basic level, it really boils down to the fact that the same observer can’t simultaneously measure degrees of freedom in A and C. But one may say much more.
I really recommend you the Papadodimas-Raju paper
which makes all these things extremely quantitative (you may want to jump to sections 4,5,6 kind of directly, to skip some heavy AdS/CFT dictionaries with a lower density of new concepts). Also, I just wrote a summary of a small subsection of that paper whose value is still great here:
It’s an explanation why pure density matrices and mixed density matrices are close to each other on very large Hilbert spaces (of Hawking radiation). Exponentially small corrections to the Hawking precisely mixed density matrix, corrections of order exp(-K/hbar) per matrix element, are enough to purify the density matrix. This exponential is zero to all orders in perturbative expansions in hbar.
One may show that this is possible for “generic bases” (plausibility arguments are easy) but the two guys get much further – they pretty much explicitly calculate what all these corrections are in AdS/CFT etc. So they know the full unitary/pure answer as well as its mixed/perturbative/information-destroying approximation and can show the difference is tiny.
They find out that if you want to determine that the entanglement is maximal etc., you need to make very many observations, or exponentially precise observations. In the former case, i.e. measuring too many Hawking quanta, you will find out that you have defined your coarse-grained tensor factor of the Hilbert space to be too large in dimension and it’s precisely this situation that will prevent you from defining the “doubled degrees of freedom” beneath the horizon (inside the hole). So exactly when you approach the accuracy/number of measurements that are needed to verify the maximal entanglements of both things, the geometric picture of the spacetime with the independent regions beneath/above the horizon breaks down. But it (and effective local field theory) always holds as long as one is modest and only chooses a small enough number of the coarse-grained degrees of freedom so that the microstates of the remaining, fine-grained degrees of freedom may be assigned to each of the coarse-grained microstates.
Best regards
Lubos
5. given enough time, will everything in the observable universe be entangled with something inside a black hole eventually?
6. What always puzzles me about this description is the lack of discussion of simultaneity issues, which is the usual resolution of GR ‘paradoxes’. As Alice approaches the horizon her Kerr time coordinate is in our very distant future. I don’t understand the technicalities of Hawking radiation but it seems to me that if we are generating it arbitrarily close to the horizon then as seen by a distant observer it only appears long after the stellar collapse (the null geodesics that the Hawking radiation follows reach the outside at large future t). So I worry when you say “maximally entangled with another system (as is the case for a sufficiently old black hole)” – old in which time coordinate? Can you clarify for me?
• .. or is that the resolution, that Alice arrives at the horizon at large future t, at which point the hole HAS ALREADY EXPLODED in the final Hawking blast and that wave of Hawking photons is the thing that incinerates her? So she never reaches the horizon?
• Though in classical general relativity the horizon is a surface with infinite red shift, the Hawking radiation still manages to escape. Another point emphasized in AMPS, which for the sake of brevity I skipped in my discussion, is that if B is entangled with C once it propagates far from the horizon, then it was already entangled with C while still close to the horizon, e.g. of order a Planck length away. (They call this the local effective quantum field theory assumption.) It is this entanglement of B with C when B is still close to the horizon which seems to imply firewalls.
• What _do_ you think of the paper to which Lubos Motl referred you?
thanks,
Raghu.
7. It is not quite clear for me, if monogamy could be used in some universal way,
e.g. there is an analogue of Bell pair for three spin-1 particles (qutrits) –
it is completely antisymmetric entangled state of such particles.
Why did not consider ABC in such a state?
• LIke any three-part state, the Aharonov state obeys a monogamy relation like the one I stated in my post, if we use an entanglement measure such as distillable entanglement or squashed entanglement. The key point is that nothing prevents us from considering a state in which B and C are nearly maximally entangled, and in fact we expect such a state to arise when the black hole is old enough. At that point, monogamy implies that A and B are nearly unentangled, hence a firewall.
• The RMP article above claims that only squashed entanglement may be
appropriate for such a state and some subtleties with this measure (eg cf the same RMP paper) maybe also are not occasional. Either unitarity or “irreversible” measures…
8. This post encourages me to think over what happens when half of a Popescu-Rohrlich box is hidden inside a black hole . :)
9. My thoughts have turned to randomness and the nature of asking a black hole questions. If you had an infinite mass black hole, and one thought (wrongly) that all information coming out of the black hole was random, then after a sufficient number of queries, one would get a string of information that would appear to be a history of Alice conducting experiments after jumping into the hole. However, a black hole is finite in mass and contains finite information, if information coming out of the black hole is correlated with information going in then I think we all agree that Alice’s post fall information must be inaccessible. However, that inaccessibility is largely associated with the apparent macroscopic properties of the black hole which imposes limits on the ultimate size of the measurable data. The question then is when does the information about Alice’s activities become destroyed?
The information extracted from the evaporating black hole must be better than random. However, accepting a complexity argument, Alice’s signal must be quantitatively closer to random to make it inaccessible if sent at all. If we accept that Alice’s post fall information is inaccessible, yet still representable as part of the pure density state then I think we can partition the Hilbert space accordingly. These in my mind represent information pockets that are effectively outside any accessible decryption schemes. I would be tempted to suggest these represent background noise. Whether these can also be tied to the idea of pocket universes is intriguing.
Beyond some of the concerns about firewalls that have already been stated, I have an additional one in that if we accept the firewall scenario, the wall of radiation encountered by the in-falling observer (Alice) could be interpreted as the black hole measuring Alice. The wall of particles encountered would not be entirely random. I am stuck on this idea that the proposal of firewalls is effectively a claim that black holes are part of a type of quantum teleportation scheme, however it seems that the concept breaks down at the our assumptions about EPR pairs. Will have to think a little more on this.
10. What happens if Alice and Bob are entangled and Alice enters the black hole? I understand it this way. Say, Alice and Bob are in the first Bell state Alice being the first qubit. As she enters the black hole, at some point she gets fried. This means the state of the first qubit changes. In that case, the state of the second qubit at Bob’s end outside the black hole also changes. According to the Landauer’s principle, change in energy at Bob’s end is kT · ln 2. Can I say that there is also a complementary change of same amount of energy inside the black hole?
11. Pingback: Firewalls! | Sean Carroll
12. I had thought that the inside of a black hole, i.e. inside the event horizon, mostly consisted of photons orbiting the singularity, much like planets & such orbit a sun, but losing energy the further out the photons travelled instead of velocity. Particles would mostly be found near the singularity, spiraling in on a one-way trip to being converted to photons. So when Alice crosses the event horizon, gravitationally there would be negligible difference, but she would smack into the “holeopause” of extremely low-level radiation lurking just below – the firewall of AMPS. But would this extremely long-wavelength radiation, however intense, be sufficient to disrupt any quantum entanglement? It’s as if water drops hit a cold skillet and started dancing over the surface as if it were hot.
• Jacobson asserts that his description is “dual” to the AdS/CFT description by Papadodimas and Raju, which Lubos referenced in a previous comment. In the notation of my post above (as Lubos explained), it seems that we should think of A and C as complementary descriptions of the same system, rather than separate subsystems. Monogamy of entanglement is not violated — it’s possible for B to be maximally entangled with A and also maximally entangled with C if A and C are the same system!
Perhaps that’s right (I’m not sure), but it seems quite bizarre because the map between A and C is so highly nonlocal. A is behind the black hole horizon and C, a system of Hawking radiation emitted eons ago, is distributed in intergalactic space zillions of light years from the black hole. Bob, hovering just outside the horizon, should be able to influence the state of A by dropping something inside the horizon. Hence he would be able to influence C, which if far, far away.
I guess we accepted long ago that quantum gravity is intrinsically nonlocal — that strict locality is an emergent property of semiclassical physics — so the question is how nonlocal can it be? The nonlocality in the above scenario seems extreme, but could it be true? Maybe.
• Dear Prof Preskill,
the maps in the black hole complementarity have always been nonlocal – for two decades. I wonder why you (and others) have never protested that the black hole complementarity looked strange to you since the early 1990s and why the explosion of the anti-complementarity revolt was waiting for the year 2012. It has never looked strange to me. What looks strange to me is the sudden overgrowth of irrational complaints and flawed arguments that suddenly want to claim that complementarity is wrong.
In fact, the map’s being heavily nonlocal and complicated – Raju and Papadodimas also tell you how analytic continuation to complex values of time is important for a natural transformation of the degrees of freedom that undo some of the complementary code – is actually needed for the effective local field theory description to work sufficiently well in all the regions.
For example, the Hawking-style perturbative treatment of QFT on a black hole background gives a mixed state to all orders in the perturbative expansion; nevertheless, the exact result for the Hawking radiation is pure (assuming a pure initial state). This is no contradiction because pure and mixed density matrices may be insanely (exponentially) close to each other in high-dimensional Hilbert spaces:
What’s necessary for this proximity, however, is that the matrix form of “natural observables” for the observer inside the black hole are heavily off-diagonal and diagonalized in a pretty much “random basis” relatively to the exterior observer. In other words, a necessary condition for Nature to be able to preserve the approximate validity of all these points of view and locality in all the regions related by complementarity *is* that the map between the degrees of freedom that are identified is very complicated, essentially chaotic. But it surely is. In Raju-Papadodimas’ language, the emergence of the two regions / complementary descriptions is a special property of pure states that are close to mixed ones (and such pure states are complicated and boast lots of random phases etc.). There’s a lot of other evidence or proofs that the map is complicated. For example, the black holes are the “fastest scramblers”, using the jargon of Susskind and a collaborator. This really means that they’re able to mix up the complex amplitudes in state vectors very quickly and very thoroughly. So even ordinary “waiting” operation produces chaotic rearrangements of the whole accessible Hilbert space of the black hole microstates. It shouldn’t be surprising that if we “leave” the black hole at two different moments, in two different directions, the map between the information as seen by the natural degrees of freedom on the two “exits” will be impenetrable.
Maybe you didn’t mean that the complementarity map is “complicated” and you really meant that it’s nonlocal in the sense that it relates degrees of freedom we associate with different regions – but this is true really by definition. If a map related degrees of freedom in the same region but at different points, by some simple enough map, then the locality in that region would be heavily violated, wouldn’t it? But in practice, the fact that we’re related “two different spaces/regions” is no more mysterious than the fact that the Fourier transform (relevant for the ordinary Bohr complementarity) relates two different spaces – the coordinate space and the momentum space.
Best regards
Lubos
• It seems to me that the nonlocality we are now contemplating in the Papadodimas-Raju scenario goes beyond the previously accepted nonlocality in the black hole complementarity hypothesis, at least as I had understood it. This relates to our exchange on Dec. 4 regarding whether the A-B entanglement and the B-C entanglement are both verifiable. If as your claimed (but I did not fully understand) it is not possible to verify both types of entanglement, then the Papadodimas-Raju picture may hold together fairly well.
In the picture I thought I had previously understood (explained in this paper with Hayden), there was a nonlocal map relating observables inside the black hole to observables in the exterior. But this nonlocality could not be discerned by the outside observer Bob. From his point of view, stuff could fall into the black hole, be thermalized at the stretched horizon after the scrambling time, and then be re-emitted in the Hawking radiation in a highly scrambled form. In contrast, the A=C hypothesis seems to suggest that Bob can influence C without waiting for scrambling and re-emission. Maybe I have that wrong.
Anyway, the A=C hypothesis seems more plausible to me than firewalls or violations of unitarity.
13. On the monogamy of entanglement. I’ve confused myself about the following: Suppose you have a system A that’s composed of 2n spin states that are n pairwise entangled pairs, and another system B with 2m states that are m pairwise entangled states. Can A and B be entangled? I am thinking, yes, they can if the states are distinguishable, for example by location. You could have two different pairings in A and two different pairings in B and entangle them much like you’d entangle states rather than pairs of states. Does that make sense?
• Dear Sabine,
note that your scenario only contains two letters A,B, so it isn’t in conflict with monogamy which bans two entanglements among the 3 groups of degrees of freedom (e.g. 3 groups of qubits) A,B,C: it says that A-B and B-C maximum entanglements are impossible. You don’t have any C so it’s no contradiction with monogamy.
In your scenario, you may divide A to A1,A2 – the two groups of spins that are up for A1 and down for B2, or vice versa. Similarly, B may be split to the maximally entangled collections B1,B2. Then monogamy says that A1 can’t be maximally entangled e.g. with B1. It’s important that in the monogamy statement, A1 or B1 that are prohibited from having two spouses are fixed collections of qubits. So if you discuss “two different pairings” in A, you are apparently dividing A to A1,A2 or A3,A4 by two different cuts. But it’s like changing the rules of the game. The no-monogamy law says something about what A1 isn’t allowed to do; or A2 isn’t allowed to do. What A3 or A4 does is an entirely different issue.
There’s no contradiction between your state of the qubits in A,B and the no-monogamy law. You just constructed something that “vaguely feels” that it has “too much entanglement” or “several types of entanglement”. But the no-monogamy law isn’t a wide assertion about all vague sloppy statements one could make. It is a very particular claim about A,B,C that you haven’t violated.
Incidentally, the key claim in your firewall paper – that the early and late Hawking radiation isn’t entangled – is totally indefensible given the current knowledge of black hole information. The entanglement between “already emitted radiation” and the “remaining black hole” is demonstrably increasing up to some point because the Hawking pairs (one outgoing, one incoming) are clearly entangled with each other. This increases the remaining_black_hole – old_radiation entanglement, and the remaining black hole is then unitarily evaporated into the late Hawking radiation, so the late Hawking radiation must be entangled with the early one, too.
Your last paper about gravity not being quantum is wrong as well but it’s arguably “off-topic” – it’s a claim that would make all the discussions above totally irrelevant but be sure they’re not irrelevant.
Best regards
Lubos
• Dear Lubos,
Thanks for the explanation. I wasn’t trying to construct any “contradiction” as you seem to believe, I was simply trying to understand what the monogamy is about. Neither was I thinking in particular about the ABC subsystems in the firewall paper. So let me summarize it like this: If I have a system A with objects a_i, each of which is entangled with a partner in A, then A can still be entangled with another system B because, as you put it “different cuts change the game.”
Re firewall: I didn’t claim that the early and late radiation is not entangled. I said, if it is not, then there’s no problem. To be more precise, they can be entangled, just not too much. You should know that I don’t believe in the statisical interpretation of the BH entropy anyway, so the whole “firewall” problem, for what I am concerned, is a non-problem.
Best,
Sabine
• Dear Sabine, you say that you were trying to understand what monogamy was about – you wrote it now – but you also discussed, in the very same discussion, some particular collections of qubits divided into pairs of qubits that are entangled etc.
So one would think that the reason why you talked about this collection of qubits is that you thought that this thought experiment about qubits was relevant for the monogamy theorem, and I explained to you why it wasn’t. But if you already discussed your thought experiment because it had nothing to do with the question and you think it’s logical to discuss thought experiments that have nothing to do with the question you are trying to understand, then I apologize I can’t help you because I am confined into the narrow-minded and obsolete male logic that tries to discuss arguments that are relevant, not irrelevant.
The early and late Hawking radiation is not only entangled; when one makes the cut in the middle of the radiated entropy, it is nearly maximally entangled.
I hear you don’t believe the statistical interpretation of entropy. What can I say about that except for a capitalized WOW? The fact that entropy is always interpreted statistically in a complete microscopic theory has been known since the 19th century insights by people like Boltzmann. Is that fashionable in the contemporary Northern European physics to dismiss such basic things and be proud about it?
All the best
LM
• It is quite amusing that you write you are “confined into the narrow-minded and obsolete male logic that tries to discuss arguments that are relevant, not irrelevant” while you are the one bringing up one after the other irrelevant distraction, including your attempt to guess reasons for my question and misinterpret my motivation to seek understanding. I have zero interest to continue this discussion – experience tells me it will be a waste of time. Ha det så bra, Sabine
• Let me be even more clear now. You wrote that you wanted to understand monogamy and in the very same comment, you presented a situation involving two groups of qubits that you wanted to be explained.
I have explained that it didn’t obey the conditions of monogamy so it had no relevance. You apparently didn’t like the fact that I pointed out that your scenario wasn’t a scenario relevant for monogamy – Prof Preskill told you the same thing.
So you started to mask why you were writing about this wrong – for monogamy irrelevant – thought experiment. But there simply isn’t any conceivable way for you to suggest that you haven’t done anything silly. You were demonstrably thinking about a situation that isn’t a realization of monogamy. There are only two possibilities: you either didn’t know that your scenario wasn’t a valid scenario to discuss monogamy because you didn’t have three groups of quantum degrees of freedom in it at all; or you did realize that your scenario was irrelevant.
In the first case, it just means that you didn’t know what monogamy claims and you tried to guess what it is and your guess wasn’t quite right, so you were corrected and you had a chance to learn something. In the second case, it follows that you lack basics of logical reasoning because you are deliberately proposing arguments that you know to be irrelevant for the points you are trying to discuss.
At any rate, it has to be one of these two things, and if you try to spread fog claiming that it was none of the things above, you are just being demonstrably dishonest.
• You implicitly divide A into subsystems A1-A2 and B into subsystems B1-B2, and consider a superposition in which the “pairing” of A1 with A2 is correlated with the pairing of B1 with B2. You are asking, I think, whether the monogamy of entanglement is violated because A1-A2 is maximally entangled yet A2 has some entanglement with B.
In this case, though, A1-A2 is not maximally entangled — rather its state is a mixture of distinguishable maximally entangled states. In this mixture, the A1-A2 entanglement is reduced sufficiently for monogamy of entanglement to be satisfied.
• Yes, thanks, that’s what I was wondering. Is there a way to quantify how non-maximal the entanglement is? Consider A is an ordered chain of its constituents a_i, with i=1..2n, and you can pairwise entangle them in all possible orders. Same for B with b_j, j=1..2m. How would I figure out what entanglement is possible between A and B?
• I believe what you are asking is the how to measure entanglement between two systems A,B. A quick reference is found at in Structured Quantum Programming ( //tph.tuwien.ac.at/~oemer/doc/structquprog.pdf ) under 1.2.3.4 Composite Systems. Another good discussion is found in Exploring the Quantum, Haroche and Raimond, Section 2.4.3 Schmidt Expansion and entropy of entanglement. In any case, remember that in the simplest cases, entanglement is a statement about the idempotency of the density matrix. The trace of the squared density matrix, Tr(rho^2), will take take a value between 1/n and 1 where n is the size of the matrix.
• Dear Hal,
The idempotency of the density matrix is a measure of purity (how close the quantum state is to a pure state). You are probably thinking of how pure the reduced density matrix of a pure state is, along a particular cut. The more pure the reduced density matrix, the closer to an unentangled (product) state the original state will be.
• Thank you. I have a horrible tendency of over-generalization due to a tremendous lack of time. The three thoughts in my head at that moment where:
1. Density matrices at n = infinity
2. All “classical” statistical mixtures are composed of something that could only be described by representations of “pseudo-pure” states. IOW, as we talk about pure states, coherence and entanglement, we have to recognize that at some point the notion of separable pure states breaks down since off-diagonal components of the density matrix can never really vanish.
3. In certain constructions of the density matrix, such as the reduced density matrix, and because of the close relationship between entanglement and coherence, we can generalize the degree of entanglement into a type of phase factor that for lack of a better word can be understood as idempotency.
• Thanks :) I’ll look up these references.
• My pleasure. One last comment for clarity. As you probably know, Von Neumann Entropy is also used as a measure of entanglement, however it is only based on the diagonal components of the density matrix …e.g. S = -tr(rho ln rho). So this measure, by definition, disregards information about the off diagonal components. The test for purity (what may be viewed as idempotency), relies upon the square of the density matrix, and thus retains information about the off diagonal components, and because of the closeness of the relationship of coherence and entanglement one can capture information about entanglement in the measure, however, at a fundamental level one needs to keep the two concepts separate. That said, in certain circumstances, I would argue the purity measure (tr(rho^2)) can serve as an entanglement measure, and as mentioned above, in reality the off diagonal components never truly vanish even though it is convenient to assume they do when performing calculations.
• Dear Hal,
I am afraid that I must once again play the role of the entanglement police :)
First thing I would like to clarify is that the von Neumann entropy depends on all elements of the matrix, not just the diagonal ones. As you noted, the entropy is given by $S=-Tr(\rho \log \rho)$, and even though the trace of a matrix only depends on the diagonal elements, because of the multiplication with the logarithm of the density matrix inside the trace, this is no longer true (that the entropy S still depends only on the diagonal elements of the matrix $\rho$). What is always true is that the entropy (as well as the purity) are functions of the eigenvalues (only) of the density matrix in question. In other words, your intuition is correct, but only once we have rotated our viewpoint to the basis that diagonalizes the density matrix.
The second thing to clarify is that purity and entropy are not measures of entanglement in the sense that you think: coherence and entanglement are not connected to each other. You can have a fully coherent state that has no entanglement (product state of two coherent states) and another coherent state with maximal entanglement (Bell-like state). It is the choice of a cut of the state into two parts and the subsequent use of either entropy or purity on the *reduced* density matrix that determines the amount of entanglement present in the initial pure state. If the initial state is mixed, then things become even more complicated and one may need to use different measures of entanglement like Entanglement of Formation, or Squashed Entanglement to see how much entanglement can be extracted from the initial state.
[Note: In the discussion about coherence vs entanglement above, I have made the assumption that your use of the term coherence means purity, but it may be that you really mean Glauber coherent states – that is, states satisfying the Least uncertainty in position and momentum (Gaussian states). Please specify what coherence you were referring to, in case I assumed incorrectly.]
• Thanks, definitely appropriate corrections and certainly adds clarity. As you surmised I was only thinking about coherence in a general sense. In any case, in the case of firewalls, one wonders if it is appropriate to make a claim of starting with a pure state and propose its unitary evolution and then inject another classical entity into the mix arbitrarily, I am not sure why that procedure makes sense, or if it is given that is mechanically possible without qualification.
14. If anyone is interested, here is an updated line of thinking. I was thinking along the lines of the issue of auto-synchronization of oscillators (like metronomes) in classical physics, which at some level becomes a question of how a massive fermion knows what its mass is supposed to be when it crosses the black hole horizon. Of course we know now that the Higgs field and spontaneous symmetry breaking leads us to a Higgs condensate which can then give particles mass. So the situation of no firewalls implicitly assumes the Higgs field has the same effect inside the horizon as outside the horizon. If we look at the firewall scenario, and the injection of an arbitrary third entity, if they have not co-evolved with the other parties, then it seems reasonable to question why we would expect them to share the same broken symmetry as it relates to their mass.
So the question is whether there are any analogous scenarios that one can reference, and after a while one thinks more about the metronome situation, and Dynamical Mean Field Theory and Ising models start coming into view. What also comes into view is the problem of Domain Wall formation and other topological solitons. The firewall proposal seems very similar, since there is an energy and temperature that must be associated with the firewall. It turns out there are a few Arxiv articles ( http://arxiv.org/pdf/hep-ph/0204154v1.pdf ) that discuss the possibility of EPR correlations in the Higgs field explaining away domain wall formation. To quote the referenced paper. “just the large energy concentrated in the domain walls turns out to be the factor substantially suppressing the probability of their formation.”
This sort of non-locality in the Higgs field is not prohibited I think in the firewall scenario. It seems that there is no reason for us to think that the physics inside the horizon is substantially different from outside the horizon given that the extra entity (Carrie for instance) shares the same physics as Alice and Bob before Alice jumps into the black hole. In the Higgs field, we have an example of a global means of coupling physics in some sense a priori to the situation in question. This is especially important I think when we talk about massive objects, and the very mass we are talking about we now know requires a mechanism like symmetry breaking to occur very early in evolution in order for mass to even be quantifiable.
Maybe my thinking is wrong on this.
15. In a paper published in Z. Naturforschung 56a, 889, 2001, I had explained the following: The w^3 spectrum of the zero point vacuum energy, obtained by quantum mechanics with E= 1/2 hw, multiplied with 4pi x w^2 dw, proportinal to w^3, assumes the only form which is Lorentz invariant. Therefore, one can say the Minkowski space -time is “generated” by the zero point vacuum energy. But if cut off at the Planck energy, it is Lorentz invariant only up to this energy, generating a distinguished reference system in which the zero point energy is at rest. According to the pre-Einstein theory of relativity by Lorentz and Poincare, for velocities below the velocity of light (in this reference system), objects are held together in a static equilibrium by electrostatic forces (or forces acting like them), by a solution of an elliptic partial differential equation derived from Maxwell’s equations. In aproching the velocity of light this differential equation goes over the Euler-Tricomi equation into a hyperbolic differential equation where there is no such equilibrium. In gas dynamics this is analogous to the transition from subsonic to supersonic flow. But this is the same sort of transition which happens in approaching the event horizon, where the flow against the zero point energy reaches the velocity of light. For astronomical objects with velocties small to the velocity of light against this reference system, special and general relativity remain good approximations, but not for objects (or elementary particles) approaching the event horizon. Now, for a collapsing large spherical mass, the event horizon first appears in the center of the mass as a point, and in reaching this point the energy of particles can reach the Planck energy, whereby the particles decay into leptons and photons, with the result that the entire mass is converted into a gamma ray burst. This result is in agreement with the observed gamma ray bursters where a solar mass m is fully converted into radiation according to E = mc^2. Under these circumstances unitarity is not violated, and there can be no particle entanglement crossing the event horizon. As it turns out, a black hole is the best particle accelerator, reaching particle energies 15 orders of magnitude larger than the LHC. But it must not always lead to a gamma ray burst. I believe it was Jeans or Eddington who noticed that there is a flow of hydrogen coming from the center of the galaxy. This then might happen for a very large black hole, where in a slow collapse towards the event horizon in the center, gamma rays accelerate the hydrogen out of the center.
16. “Is Alice burning? The black hole firewall controversy | Quantum Frontiers” really enables me personally contemplate a little bit extra.
I actually admired every individual element of it.
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https://dev.ammoniaenergy.org/topics/plasma/
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A scalable, cost-effective catalytic process of ammonia synthesis is developed by using microwave excitation under mild reaction conditions. In this research project funded by DOE ARPA-E, our interdisciplinary team of WVU, NETL, PNNL, FSU and two industrial partners have demonstrated that ammonia synthesis can be carried out at 200-300 °C and ambient pressure. This transformational process integrates system elements of electromagnetic sensitive catalysts and microwave reactor design. Taking advantages of state-of-the art non-equilibrium microwave plasma technology, catalytic ammonia synthesis undergoes a new reaction pathway where the barrier for the initial dissociation of the dinitrogen is decoupled from the bonding energy…
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Introduction: In 1909, a compound named Ammonia was discovered. Through the 20th century, the immense potential of this chemical was exploited by using in almost every product, from process industry for fertilizer and chemical production to every use in cosmetics, household cleaners and medicines. Recently, fuel cells operating on liquid ammonia as working fluid have been developed on research scale. Despite of using 1-2% of total energy production for the synthesis of this compound, no significant changes have been made to the process since the first Haber-Bosch process plant has been setup. Plasma catalysis is the use of plasma and…
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Ammonia has much more uses than being a fertilizer. Its emerging applications include hydrogen carrier, fuel cells, clean transportation fuels, and other off-grid power applications. The traditional Haber Bosch process used to synthesize ammonia must be achieved at high temperature and pressure. The non-thermal plasma (NTP) allows for the synthesis of ammonia at a lower temperature and pressure conditions. It is proposed that the moderate process conditions can potentially allow a more economical construction and operation of ammonia production systems on distributed farms and renewable hydrogen production sites. In this study, we report the NTP synthesis of ammonia using dielectric…
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Over the last few weeks, I've written extensively about sustainable ammonia synthesis projects funded by the US Department of Energy (DOE). While these projects are important, the US has no monopoly on technology development. Indeed, given the current uncertainty regarding
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Plasma-Enhanced Ammonia Combustion Jason Ganley, NHThree LLC
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Ammonia Synthesis Using Nonthermal Plasma with Ruthenium Catalysts Zhiping Le, Shaobo Deng, Paul Chen, and Roger Ruan, University of Minnesota
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http://mathhelpforum.com/differential-geometry/168060-transformation-matrices-tetrahedra.html
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# Math Help - Transformation Matrices - Tetrahedra
1. ## Transformation Matrices - Tetrahedra
Hello everyone!
I was wondering if anyone out there could help me with some 3d geometry transformations.
What I've got:
I have a tetrahedron (A) in Cartesian space, centred at the origin, with vertices at:
(1,1,1) , (-1,-1,1) , (-1,1-1) & (1,-1,-1).
What I would like:
A tetrahedron (B) with vertices at:
(-1,-1,-1), (0,-1,0), (-1,0,0), (0,0,-1)
The question:
How does one find the transformation matrix to transform tetrahedron A into tetrahedron B?
Any help will be greatly appreciated
2. This can't be expressed as a linear transformation A.
Your original vectors v1+v2+v3+v4 = 0
However, your new vectors v1'+v2'+v3'+v4' = (-2,-2,-2)
If this was a linear transformation:
Av1 + Av2 + Av3 + Av4 = A(v1+v2+v3+v4) = 0
If you wanted this transformation, you will at least have to use affine transformations.
Trying to solve the matrices I just realised (as you say) it is unsolvable as a linear transform. So how would one find the affine transformation?
4. For affine transformations, you just add in a scale factor (which is normally the unit).
For example, (1,1,1) would be represented as (1,1,1,1).
Then you can do a linear transformation in 4 dimensions.
In general, an affine vector (a,b,c,d) is the same thing as the 3d vector (a/d, b/d, c/d).
However, I'm not sure this is the best way for you to go.
What are you trying to do?
5. I'm using structure synth to create a fractal. So I want to put map tetrahedrons onto the 4 face's of a larger tetrahedron. In sturcture synth you only have option of using a 3x3 transformation matrix though...
6. Actually, most 3d drawing software allow affine transformations. They are needed for translations and also perspective projections.
My suggestion is for a fractal, the tetrahedron should at least be similar (which is not the case for your example).
If they are similar, you can easily draw it with a scaling, rotation, and translation (which is an affine transformation).
Also, perhaps it is easier to use the scaling rotation and translation primitive instead of constructing the matrix yourself (essentially let the computer do it for you).
7. The tetrahedrons are self similar, I can post a screen shot if you'd like... The second one is a smaller version of the larger, but all lengths are scaled linearly and then rotated and translated...
Attached Thumbnails
8. So to clarify the larger tetrahedron (red) has edges all of length 2sqrt(2) and smaller has edges sqrt(2). All faces are equilateral -> so they must be self similar...
9. Originally Posted by perrelet
The tetrahedrons are self similar, I can post a screen shot if you'd like... The second one is a smaller version of the larger, but all lengths are scaled linearly and then rotated and translated...
Yes, they are definitely similar
I didn't do a thorough calculation.
Some kind of 3D Koch curve I see.
So you must have been able to describe the transformations to draw that picture.
10. Hey snowtea
I drew that picture by explicitly stating the coordinates of both tetrahedra to the program. However I want the program to build the second by reiterating the first and applying a transformation, as this method will allow me to add levels of tetrahedra arbitrarily deep into the figure...
I've tried to solve the system of equations by transforming each vertex on one tetrahedron into the vertex on another, as (for example) follows:
(1,1,1) => (0,-1,0)
(-1,-1,1) => (-1,-1,-1)
(1,-1,-1) => (0,0,-1)
(-1,1,-1) => (-1,0,0)
But when I solve the system for the transformation matrix as it is done in 2D in this thread: https://nrich.maths.org/discus/messa...tml?1140864401. My system of equations is not solvable...
Not sure why?
11. Like a said, it is not a linear transformation (in 3 dimensions), so of course you won't be able to solve it.
Express it as a composition of simple transformations (on your coordinate axes) in this order:
Scaling then Rotation then Translation.
Then you can use the exact same drawing routine since your new coordinate axes are transformed.
Note: You will have to use quite a bit of trig.
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https://brilliant.org/problems/wired-up/
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# Wired Up
Classical Mechanics Level pending
A piece of uniform wire is bent intro three sides of a square $$ABCD$$ so that the side $$AD$$ is missing.
If it is first hung up by the point $$A$$ and then by the point $$B$$, the acute angle between the two directions of $$BC$$ is $$\arctan{x^\circ}$$. Find $$x$$.
×
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http://zbmath.org/?q=an:1036.06502&format=complete
|
zbMATH — the first resource for mathematics
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Lattice cyclically ordered groups. (English) Zbl 1036.06502
Summary: The notion of a cyclically ordered group (CO-group) was introduced by L. Rieger. Some properties of right cyclically ordered groups (RCO-groups) and of partially cyclically ordered groups (PCO-groups) were previously investigated by the author. It was proved that the group of automorphisms of a cyclically ordered set is an RCO-orderable group.
In this paper the notion of a lattice cyclically ordered group is introduced. It is proved that the group of automorphisms of a cyclically ordered set is a lattice cyclically orderable group.
MSC:
06F15 Ordered groups
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http://math.stackexchange.com/questions/182725/how-to-recover-three-successive-rotations-of-a-vector
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# How to recover three successive rotations of a vector
I have a vector, which I rotated with respect to $x$, $y$ and $z$ axes, respectively.
Now I want to recover this operation, that means I want to bring it to the previous position by rotating it with $-\theta$, $-\alpha$ and $-\beta$, where $\theta$, $\alpha$ and $\beta$ are the amounts of initial rotation, in radians/degrees.
I tried to do it by computing the dot product of this vector with axis vectors ($(1,0,0)$ for $x$-axis, $(0,1,0)$ for $y$-axis and $(0,0,1)$ for $z$-axis).
However, this did not produce the right result possibly because It was rotated in 3d, thus the dot product was resulting in a different value that it should be.
What I should do in order to perform this operation? Thanks.
-
do you mean you rotated using Euler angles? or did you rotate around the fixed axes? – nbubis Aug 15 '12 at 7:03
I'm not really sure what you're asking. Do you mean that you know the position $x$ of your point before rotating, the position $x'$ of the point after rotating, and then you want to find the angles $\theta,\alpha,\beta$ such that $x'$ gets send back to $x$? Or do you already know $\theta, \alpha,\beta$ and you just want to know how to use these to create a rotation that sends $x'$ back to $x$? – Lieven Aug 15 '12 at 7:12
@Lieven The latter one. I know $\theta$,$\alpha$ and $\beta$, and I want to find the rotation that sends $x'$ back to $x$. – user13791 Aug 15 '12 at 8:00
@nbubis using Euler angles. – user13791 Aug 15 '12 at 8:31
As @nbubis mentioned, Euler angles is what you are looking for. – Sait Aug 15 '12 at 8:34
If you used Euler angles, simply multiply your vector by the rotation matrices in reverse order. If you used $\alpha$ around $\hat{x}$, then $\beta$ around $\hat{y}$, and finally $\gamma$ around $\hat{z}$ to get at a vector $v$, then the original vector $v_0$ is given by: $$v_0 = Z(-\gamma)Y(-\beta)X(-\alpha)v$$ Where $X,Y,Z$ are the rotation matrices.
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