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VeNom Coding Group
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VeNom Codes membership
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The VeNom Codes have been developed in the first opinion and referral hospitals at the RVC in collaboration with Glasgow Vet School and the PDSA and are now maintained by a multi-institution group of veterinary clinicians and IT specialists from the RVC, Glasgow Vet School and the PDSA called the VeNom Coding Group.
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VeNom Coding Group
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VeNom Codes membership
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A small group of members from various institutes manage and maintain the list of terms, and invite or authorize others to use the term. A second group of members provide the scientific input to ensure the list is peer reviewed and correct - these members can be any one who uses the list. Any disputes over the list will be solved by a general consensus and overseen by the management group.
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VeNom Coding Group
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VeNom Codes
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The VENOM codes comprise an extensive, standardised list of terms for recording the best available diagnosis at the end of an animal visit. It comprises mainly diagnoses but also includes terms appropriate for administrative transactions (e.g. non prescription diet sales, over the counter items, travel related items) and preventive health visits (vaccination(s), routine parasite control, neutering). In the event that the clinician seeing the animal feels unable to record a diagnosis for the visit (for example, on a first consultation when only limited diagnostic workup has been possible, e.g. coughing where a precise diagnosis is not yet available) it is also possible to select one or more presenting complaints (again, these are standardised in the list). If an item is missing from the list, please advise us and we will make the necessary adjustments if required. We are currently working on other lists (procedures etc.) and these will be added to the VENOM codes in due course.
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VeNom Coding Group
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VeNom Codes
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The VENOM codes are a long list of conditions (Term name) identified by their unique numeric codes (Data Dictionary Id). There is a label field to identify the type of term (Container and Container ID–e.g. diagnosis, presenting complaint, administrative task etc.). The Top level modelling field includes the parent grouping / body system for each term. There is also a CRIS Active flag which is elected if the PMS prefers the referral centre version. In this version presenting complaints are stated without 'presenting complaint - ' prefix and the administrative tasks are excluded. For the first opinion version the Rx Active flag field allows selection of this version and includes presenting complaints with the prefix ‘presenting complaint -’ to highlight this is not strictly a diagnosis. The final field is the Active Flag key which indicates if the term is active or has been inactivated.
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VeNom Coding Group
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VeNom Codes
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The VENOM Codes have been developed in the first opinion and referral hospitals at the Royal Veterinary College (RVC) in collaboration with Glasgow Vet School and the PDSA and the codes are now maintained by a multi-institution group of veterinary clinicians and IT experts from the RVC, Glasgow Vet School and the PDSA called the VENOM Coding Group. The codes are a long list identified by their unique numeric code and work best with a multi-letter search function–so clinicians type ‘abs’ and get all possible terms with abs as first letters of any of the words in the diagnosis–e.g. ‘anal sac abscess’, ‘abscess–neck (cervical)’,...etc. For some terms there are synonyms in brackets behind the main term to allow identification of the correct term if these letters are typed in the search box.
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VeNom Coding Group
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VeNom Codes
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The main concern for VENOM Codes is that all PMS's and other end-users that adopt the VENOM codes also adopt the rules of the VENOM Coding group–namely that the VENOM Coding group maintains the list. If, for example, a practitioner requests a new item, then you forward the request to us (or they go direct to us). We then put it to the VENOM Coding group to vote on and if approved it is added to the list, if not it doesn't go on the list. Our turn around on new items is 3-5 working days currently. The new item would be added to the list and then emailed out to each computer management system that uses the codes to upload to their system and practices. We are now working to 3 monthly updates, though can issue additional updates if end-users require specific terms to be added sooner. We also request that the diagnostic lists used by the PMS's and other end-users are kept restricted to the standard VENOM terms and that practitioners can not their own terms as they go along.
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VeNom Coding Group
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The Data Dictionary
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The codes are a long list identified by their unique numeric codes (Data dictionary id) and work well with a multi-letter search function–so clinicians type ‘abs’ and get all possible terms with abs as first letters of any of the words in the diagnosis–e.g. ‘anal sac abscess’, ‘abscess–neck (cervical)’,...etc. For some terms there are synonyms in brackets behind the main term to allow identification of the correct term if these letters are typed in the search box. Apart from the Term name and data dictionary id (numeric code), there is a label field to identify the type of term and then currently the other fields of the codes include a 'CRIS active flag' which is elected if you want the referral version–presenting complaints without 'presenting complaint' prefix and without the admin tasks etc. Otherwise for the first opinion version the ‘Rx Active flag’ field allows selection of this version. The final field is the Active flag which indicates if the term is active or has been inactivated.
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Sum of angles of a triangle
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Sum of angles of a triangle
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In a Euclidean space, the sum of angles of a triangle equals the straight angle (180 degrees, π radians, two right angles, or a half-turn).
A triangle has three angles, one at each vertex, bounded by a pair of adjacent sides.
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Sum of angles of a triangle
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Sum of angles of a triangle
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It was unknown for a long time whether other geometries exist, for which this sum is different. The influence of this problem on mathematics was particularly strong during the 19th century. Ultimately, the answer was proven to be positive: in other spaces (geometries) this sum can be greater or lesser, but it then must depend on the triangle. Its difference from 180° is a case of angular defect and serves as an important distinction for geometric systems.
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Sum of angles of a triangle
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Cases
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Euclidean geometry In Euclidean geometry, the triangle postulate states that the sum of the angles of a triangle is two right angles. This postulate is equivalent to the parallel postulate. In the presence of the other axioms of Euclidean geometry, the following statements are equivalent: Triangle postulate: The sum of the angles of a triangle is two right angles.
Playfair's axiom: Given a straight line and a point not on the line, exactly one straight line may be drawn through the point parallel to the given line.
Proclus' axiom: If a line intersects one of two parallel lines, it must intersect the other also.
Equidistance postulate: Parallel lines are everywhere equidistant (i.e. the distance from each point on one line to the other line is always the same.) Triangle area property: The area of a triangle can be as large as we please.
Three points property: Three points either lie on a line or lie on a circle.
Pythagoras' theorem: In a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the other two sides.
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Sum of angles of a triangle
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Cases
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Hyperbolic geometry The sum of the angles of a hyperbolic triangle is less than 180°. The relation between angular defect and the triangle's area was first proven by Johann Heinrich Lambert.One can easily see how hyperbolic geometry breaks Playfair's axiom, Proclus' axiom (the parallelism, defined as non-intersection, is intransitive in an hyperbolic plane), the equidistance postulate (the points on one side of, and equidistant from, a given line do not form a line), and Pythagoras' theorem. A circle cannot have arbitrarily small curvature, so the three points property also fails.
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Sum of angles of a triangle
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Cases
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The sum of the angles can be arbitrarily small (but positive). For an ideal triangle, a generalization of hyperbolic triangles, this sum is equal to zero.
Spherical geometry For a spherical triangle, the sum of the angles is greater than 180° and can be up to 540°. Specifically, the sum of the angles is 180° × (1 + 4f ),where f is the fraction of the sphere's area which is enclosed by the triangle.
Note that spherical geometry does not satisfy several of Euclid's axioms (including the parallel postulate.)
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Sum of angles of a triangle
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Exterior angles
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Angles between adjacent sides of a triangle are referred to as interior angles in Euclidean and other geometries. Exterior angles can be also defined, and the Euclidean triangle postulate can be formulated as the exterior angle theorem. One can also consider the sum of all three exterior angles, that equals to 360° in the Euclidean case (as for any convex polygon), is less than 360° in the spherical case, and is greater than 360° in the hyperbolic case.
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Sum of angles of a triangle
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In differential geometry
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In the differential geometry of surfaces, the question of a triangle's angular defect is understood as a special case of the Gauss-Bonnet theorem where the curvature of a closed curve is not a function, but a measure with the support in exactly three points – vertices of a triangle.
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Glasgow Haskell Compiler
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Glasgow Haskell Compiler
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The Glasgow Haskell Compiler (GHC) is a native or machine code compiler for the functional programming language Haskell. It provides a cross-platform software environment for writing and testing Haskell code and supports many extensions, libraries, and optimisations that streamline the process of generating and executing code. GHC is the most commonly used Haskell compiler. It is free and open-source software released under a BSD license. The lead developers are Simon Peyton Jones and Simon Marlow.
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Glasgow Haskell Compiler
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History
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GHC originally begun in 1989 as a prototype, written in Lazy ML (LML) by Kevin Hammond at the University of Glasgow. Later that year, the prototype was completely rewritten in Haskell, except for its parser, by Cordelia Hall, Will Partain, and Simon Peyton Jones. Its first beta release was on 1 April 1991. Later releases added a strictness analyzer and language extensions such as monadic I/O, mutable arrays, unboxed data types, concurrent and parallel programming models (such as software transactional memory and data parallelism) and a profiler.Peyton Jones, and Marlow, later moved to Microsoft Research in Cambridge, where they continued to be primarily responsible for developing GHC. GHC also contains code from more than three hundred other contributors.
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Glasgow Haskell Compiler
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History
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Since 2009, third-party contributions to GHC have been funded by the Industrial Haskell Group.
GHC names Since early releases the official website has referred to GHC as The Glasgow Haskell Compiler, whereas in the executable version command it is identified as The Glorious Glasgow Haskell Compilation System. This has been reflected in the documentation. Initially, it had the internal name of The Glamorous Glasgow Haskell Compiler.
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Glasgow Haskell Compiler
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Architecture
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GHC is written in Haskell, but the runtime system for Haskell, essential to run programs, is written in C and C--.
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Glasgow Haskell Compiler
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Architecture
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GHC's front end, incorporating the lexer, parser and typechecker, is designed to preserve as much information about the source language as possible until after type inference is complete, toward the goal of providing clear error messages to users. After type checking, the Haskell code is desugared into a typed intermediate language known as "Core" (based on System F, extended with let and case expressions). Core has been extended to support generalized algebraic datatypes in its type system, and is now based on an extension to System F known as System FC.In the tradition of type-directed compiling, GHC's simplifier, or "middle end", where most of the optimizations implemented in GHC are performed, is structured as a series of source-to-source transformations on Core code. The analyses and transformations performed in this compiler stage include demand analysis (a generalization of strictness analysis), application of user-defined rewrite rules (including a set of rules included in GHC's standard libraries that performs foldr/build fusion), unfolding (called "inlining" in more traditional compilers), let-floating, an analysis that determines which function arguments can be unboxed, constructed product result analysis, specialization of overloaded functions, and a set of simpler local transformations such as constant folding and beta reduction.The back end of the compiler transforms Core code into an internal representation of C--, via an intermediate language STG (short for "Spineless Tagless G-machine"). The C-- code can then take one of three routes: it is either printed as C code for compilation with GCC, converted directly into native machine code (the traditional "code generation" phase), or converted to LLVM IR for compilation with LLVM. In all three cases, the resultant native code is finally linked against the GHC runtime system to produce an executable.
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Glasgow Haskell Compiler
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Language
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GHC complies with the language standards, both Haskell 98 and Haskell 2010.
It also supports many optional extensions to the Haskell standard: for example, the software transactional memory (STM) library, which allows for Composable Memory Transactions.
Extensions to Haskell Many extensions to Haskell have been proposed. These provide features not described in the language specification, or they redefine existing constructs. As such, each extension may not be supported by all Haskell implementations. There is an ongoing effort to describe extensions and select those which will be included in future versions of the language specification.
The extensions supported by the Glasgow Haskell Compiler include: Unboxed types and operations. These represent the primitive datatypes of the underlying hardware, without the indirection of a pointer to the heap or the possibility of deferred evaluation. Numerically intensive code can be significantly faster when coded using these types.
The ability to specify strict evaluation for a value, pattern binding, or datatype field.
More convenient syntax for working with modules, patterns, list comprehensions, operators, records, and tuples.
Syntactic sugar for computing with arrows and recursively-defined monadic values. Both of these concepts extend the monadic do-notation provided in standard Haskell.
A significantly more powerful system of types and typeclasses, described below.
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Glasgow Haskell Compiler
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Language
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Template Haskell, a system for compile-time metaprogramming. A programmer can write expressions that produce Haskell code in the form of an abstract syntax tree. These expressions are typechecked and evaluated at compile time; the generated code is then included as if it were written directly by the programmer. Together with the ability to reflect on definitions, this provides a powerful tool for further extensions to the language.
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Glasgow Haskell Compiler
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Language
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Quasi-quotation, which allows the user to define new concrete syntax for expressions and patterns. Quasi-quotation is useful when a metaprogram written in Haskell manipulates code written in a language other than Haskell.
Generic typeclasses, which specify functions solely in terms of the algebraic structure of the types they operate on.
Parallel evaluation of expressions using multiple CPU cores. This does not require explicitly spawning threads. The distribution of work happens implicitly, based on annotations provided by the programmer.
Compiler pragmas for directing optimizations such as inline expansion and specializing functions for particular types.
Customizable rewrite rules. The programmer can provide rules describing how to replace one expression with an equivalent but more efficiently evaluated expression. These are used within core datastructure libraries to provide improved performance throughout application-level code.
Record dot syntax. Provides syntactic sugar for accessing the fields of a (potentially nested) record which is similar to the syntax of many other programming languages.
Type system extensions An expressive static type system is one of the major defining features of Haskell. Accordingly, much of the work in extending the language has been directed towards data types and type classes.
The Glasgow Haskell Compiler supports an extended type system based on the theoretical System FC. Major extensions to the type system include: Arbitrary-rank and impredicative polymorphism. Essentially, a polymorphic function or datatype constructor may require that one of its arguments is itself polymorphic.
Generalized algebraic data types. Each constructor of a polymorphic datatype can encode information into the resulting type. A function which pattern-matches on this type can use the per-constructor type information to perform more specific operations on data.
Existential types. These can be used to "bundle" some data together with operations on that data, in such a way that the operations can be used without exposing the specific type of the underlying data. Such a value is very similar to an object as found in object-oriented programming languages.
Data types that do not actually contain any values. These can be useful to represent data in type-level metaprogramming.
Type families: user-defined functions from types to types. Whereas parametric polymorphism provides the same structure for every type instantiation, type families provide ad hoc polymorphism with implementations that can differ between instantiations. Use cases include content-aware optimizing containers and type-level metaprogramming.
Implicit function parameters that have dynamic scope. These are represented in types in much the same way as type class constraints.
Linear types (GHC 9.0)Extensions relating to type classes include: A type class may be parametrized on more than one type. Thus a type class can describe not only a set of types, but an n-ary relation on types.
Functional dependencies, which constrain parts of that relation to be a mathematical function on types. That is, the constraint specifies that some type class parameter is completely determined once some other set of parameters is fixed. This guides the process of type inference in situations where otherwise there would be ambiguity.
Significantly relaxed rules regarding the allowable shape of type class instances. When these are enabled in full, the type class system becomes a Turing-complete language for logic programming at compile time.
Type families, as described above, may also be associated with a type class.
The automatic generation of certain type class instances is extended in several ways. New type classes for generic programming and common recursion patterns are supported. Also, when a new type is declared as isomorphic to an existing type, any type class instance declared for the underlying type may be lifted to the new type "for free".
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Glasgow Haskell Compiler
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Portability
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Versions of GHC are available for several system or computing platform, including Windows and most varieties of Unix (such as Linux, FreeBSD, OpenBSD, and macOS). GHC has also been ported to several different processor architectures.
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Transition-edge sensor
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Transition-edge sensor
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A transition-edge sensor (TES) is a type of cryogenic energy sensor or cryogenic particle detector that exploits the strongly temperature-dependent resistance of the superconducting phase transition.
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Transition-edge sensor
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History
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The first demonstrations of the superconducting transition's measurement potential appeared in the 1940s, 30 years after Onnes's discovery of superconductivity. D. H. Andrews demonstrated the first transition-edge bolometer, a current-biased tantalum wire which he used to measure an infrared signal. Subsequently he demonstrated a transition-edge calorimeter made of niobium nitride which was used to measure alpha particles. However, the TES detector did not gain popularity for about 50 years, due primarily to the difficulty in stabilizing the temperature within the narrow superconducting transition region, especially when more than one pixel was operated at the same time, and also due to the difficulty of signal readout from such a low-impedance system. Joule heating in a current-biased TES can lead to thermal runaway that drives the detector into the normal (non-superconducting) state, a phenomenon known as positive electrothermal feedback. The thermal runaway problem was solved in 1995 by K. D. Irwin by voltage-biasing the TES, establishing stable negative electrothermal feedback, and coupling them to superconducting quantum interference devices (SQUID) current amplifiers. This breakthrough has led to widespread adoption of TES detectors.
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Transition-edge sensor
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Setup, operation, and readout
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The TES is voltage-biased by driving a current source Ibias through a load resistor RL (see figure). The voltage is chosen to put the TES in its so-called "self-biased region" where the power dissipated in the device is constant with the applied voltage. When a photon is absorbed by the TES, this extra power is removed by negative electrothermal feedback: the TES resistance increases, causing a drop in TES current; the Joule power in turn drops, cooling the device back to its equilibrium state in the self-biased region. In a common SQUID readout system, the TES is operated in series with the input coil L, which is inductively coupled to a SQUID series-array. Thus a change in TES current manifests as a change in the input flux to the SQUID, whose output is further amplified and read by room-temperature electronics.
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Transition-edge sensor
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Functionality
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Any bolometric sensor employs three basic components: an absorber of incident energy, a thermometer for measuring this energy, and a thermal link to base temperature to dissipate the absorbed energy and cool the detector.
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Transition-edge sensor
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Functionality
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Absorber The simplest absorption scheme can be applied to TESs operating in the near-IR, optical, and UV regimes. These devices generally utilize a tungsten TES as its own absorber, which absorbs up to 20% of the incident radiation. If high-efficiency detection is desired, the TES may be fabricated in a multi-layer optical cavity tuned to the desired operating wavelength and employing a backside mirror and frontside anti-reflection coating. Such techniques can decrease the transmission and reflection from the detectors to negligibly low values; 95% detection efficiency has been observed. At higher energies, the primary obstacle to absorption is transmission, not reflection, and thus an absorber with high photon stopping power and low heat capacity is desirable; a bismuth film is often employed. Any absorber should have low heat capacity with respect to the TES. Higher heat capacity in the absorber will contribute to noise and decrease the sensitivity of the detector (since a given absorbed energy will not produce as large of a change in TES resistance). For far-IR radiation into the millimeter range, the absorption schemes commonly employ antennas or feedhorns.
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Transition-edge sensor
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Functionality
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Thermometer The TES operates as a thermometer in the following manner: absorbed incident energy increases the resistance of the voltage-biased sensor within its transition region, and the integral of the resulting drop in current is proportional to the energy absorbed by the detector. The output signal is proportional to the temperature change of the absorber, and thus for maximal sensitivity, a TES should have low heat capacity and a narrow transition. Important TES properties including not only heat capacity but also thermal conductance are strongly temperature dependent, so the choice of transition temperature Tc is critical to the device design. Furthermore, Tc should be chosen to accommodate the available cryogenic system. Tungsten has been a popular choice for elemental TESs as thin-film tungsten displays two phases, one with Tc ~15 mK and the other with Tc ~1–4 K, which can be combined to finely tune the overall device Tc. Bilayer and multilayer TESs are another popular fabrication approach, where thin films of different materials are combined to achieve the desired Tc.
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Transition-edge sensor
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Functionality
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Thermal conductance Finally, it is necessary to tune the thermal coupling between the TES and the bath of cooling liquid; a low thermal conductance is necessary to ensure that incident energy is seen by the TES rather than being lost directly to the bath. However, the thermal link must not be too weak, as it is necessary to cool the TES back to bath temperature after the energy has been absorbed. Two approaches to control the thermal link are by electron–phonon coupling and by mechanical machining. At cryogenic temperatures, the electron and phonon systems in a material can become only weakly coupled. The electron–phonon thermal conductance is strongly temperature-dependent, and hence the thermal conductance can be tuned by adjusting Tc. Other devices use mechanical means of controlling the thermal conductance such as building the TES on a sub-micrometre membrane over a hole in the substrate or in the middle of a sparse "spiderweb" structure.
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Transition-edge sensor
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Advantages and disadvantages
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TES detectors are attractive to the scientific community for a variety of reasons. Among their most striking attributes are an unprecedented high detection efficiency customizable to wavelengths from the millimeter regime to gamma rays and a theoretical negligible background dark count level (less than 1 event in 1000 s from intrinsic thermal fluctuations of the device). (In practice, although only a real energy signal will create a current pulse, a nonzero background level may be registered by the counting algorithm or the presence of background light in the experimental setup. Even thermal blackbody radiation may be seen by a TES optimized for use in the visible regime.) TES single-photon detectors suffer nonetheless from a few disadvantages as compared to their avalanche photodiode (APD) counterparts. APDs are manufactured in small modules, which count photons out-of-the-box with a dead time of a few nanoseconds and output a pulse corresponding to each photon with a jitter of tens of picoseconds. In contrast, TES detectors must be operated in a cryogenic environment, output a signal that must be further analyzed to identify photons, and have a jitter of approximately 100 ns. Furthermore, a single-photon spike on a TES detector lasts on the order of microseconds.
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Transition-edge sensor
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Applications
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TES arrays are becoming increasingly common in physics and astronomy experiments such as SCUBA-2, the HAWC+ instrument on the Stratospheric Observatory for Infrared Astronomy, the Atacama Cosmology Telescope, the Cryogenic Dark Matter Search, the Cryogenic Rare Event Search with Superconducting Thermometers, the E and B Experiment, the South Pole Telescope, the Spider polarimeter, the X-IFU instrument of the Advanced Telescope for High Energy Astrophysics satellite, the future LiteBIRD Cosmic Microwave Background polarization experiment, the Simons Observatory, and the CMB Stage-IV Experiment.
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Effects of nicotine on human brain development
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Effects of nicotine on human brain development
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Exposure to nicotine, from conventional or electronic cigarettes during adolescence can impair the developing human brain. E-cigarette use is recognized as a substantial threat to adolescent behavioral health. The use of tobacco products, no matter what type, is almost always started and established during adolescence when the developing brain is most vulnerable to nicotine addiction. Young people's brains build synapses faster than adult brains. Because addiction is a form of learning, adolescents can get addicted more easily than adults. The nicotine in e-cigarettes can also prime the adolescent brain for addiction to other drugs such as cocaine. Exposure to nicotine and its great risk of developing an addiction, are areas of significant concern.Nicotine is a parasympathomimetic stimulant that binds to and activates nicotinic acetylcholine receptors in the brain, which subsequently causes the release of dopamine and other neurotransmitters, such as norepinephrine, acetylcholine, serotonin, gamma-aminobutyric acid, glutamate and endorphins. Nicotine interferes with the blood–brain barrier function, and as a consequence raises the risk of brain edema and neuroinflammation. When nicotine enters the brain it stimulates, among other activities, the midbrain dopaminergic neurons situated in the ventral tegmental area and pars compacta.Nicotine negatively affects the prefrontal cortex of the developing brain. Prenatal nicotine exposure can result in long-term adverse effects to the developing brain. Prenatal nicotine exposure has been associated with dysregulation of catecholaminergic, serotonergic, and other neurotransmitter systems. E-liquid exposure whether intentional or unintentional from ingestion, eye contact, or skin contact can cause adverse effects such as seizures and anoxic brain trauma. A study on the offspring of the pregnant mice, which were exposed to nicotine-containing e-liquid, showed significant behavioral alterations. This indicated that exposure to e-cigarette components in a susceptible time period of brain development could induce persistent behavioral changes.
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Effects of nicotine on human brain development
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Effects of nicotine
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The health effects of long-term nicotine use is unknown. It may be decades before the long-term health effects of nicotine e-cigarette aerosol (vapor) inhalation is known. Short-term nicotine use excites the autonomic ganglia nerves and autonomic nerves, but chronic use seems to induce negative effects on endothelial cells. Nicotine may result in neuroplasticity modifications in the brain. Nicotine has been demonstrated to alter the amounts of brain-derived neurotrophic factor in humans. Side effects of nicotine include mild headache, headache, dysphoria, depressed mood, irritability, aggression, frustration, impatience, anxiety, sleep disturbances, abnormal dreams, irritability, and dizziness.The neuroregulation and structural interactions in the brain and lungs from nicotine may interfere with an array of reflexes and responses. These alterations may raise the risk of hypoxia. Continued use of nicotine may result in harmful effects to women's brains because it restricts estrogen signaling. This could lead to making the brain more vulnerable to ischemia. A 2015 review concluded that "Nicotine acts as a gateway drug on the brain, and this effect is likely to occur whether the exposure is from smoking tobacco, passive tobacco smoke or e-cigarettes."Nicotine may have a profound impact on sleep. The effects on sleep vary after being intoxicated, during withdrawal, and from long-term use. Nicotine may result in arousal and wakefulness, mainly via incitement in the basal forebrain. Nicotine withdrawal, after abstaining from nicotine use in non-smokers, was linked with longer overall length of sleep and REM rebound. A 2016 review states that "Although smokers say they smoke to control stress, studies show a significant increase in cortisol concentrations in daily smokers compared with occasional smokers or nonsmokers. These findings suggest that, despite the subjective effects, smoking may actually worsen the negative emotional states. The effects of nicotine on the sleep-wake cycle through nicotine receptors may have a functional significance. Nicotine receptor stimulation promotes wake time and reduces both total sleep time and rapid eye movement sleep."
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Effects of nicotine on human brain development
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Addiction and dependence
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Psychological and physical dependence Nicotine, a key ingredient in most e-liquids, is well-recognized as one of the most addictive substances, as addictive as heroin and cocaine. Addiction is believed to be a disorder of experience-dependent brain plasticity. The reinforcing effects of nicotine play a significant role in the beginning and continuing use of the drug. First-time nicotine users develop a dependence about 32% of the time. Chronic nicotine use involves both psychological and physical dependence. Nicotine-containing e-cigarette aerosol induces addiction-related neurochemical, physiological and behavioral changes.Nicotine affects neurological, neuromuscular, cardiovascular, respiratory, immunological and gastrointestinal systems. Neuroplasticity within the brain's reward system occurs as a result of long-term nicotine use, leading to nicotine dependence. The neurophysiological activities that are the basis of nicotine dependence are intricate. It includes genetic components, age, gender, and the environment. Pre-existing cognitive and mood disorders may influence the development and maintenance of nicotine dependence.Nicotine addiction is a disorder which alters different neural systems such as dopaminergic, glutamatergic, GABAergic, serotoninergic, that take part in reacting to nicotine. In 2015 the psychological and behavioral effects of e-cigarettes were studied using whole-body exposure to e-cigarette aerosol, followed by a series of biochemical and behavioral studies. The results showed that nicotine-containing e-cigarette aerosol induces addiction-related neurochemical, physiological and behavioral changes.Long-term nicotine use affects a broad range of genes associated with neurotransmission, signal transduction, and synaptic architecture. The most well-known hereditary influence related to nicotine dependence is a mutation at rs16969968 in the nicotinic acetylcholine receptor CHRNA5, resulting in an amino acid alteration from aspartic acid to asparagine. The single-nucleotide polymorphisms (SNPs) rs6474413 and rs10958726 in CHRNB3 are highly correlated with nicotine dependence. Many other known variants within the CHRNB3–CHRNA6 nicotinic acetylcholine receptors are also correlated with nicotine dependence in certain ethnic groups. There is a relationship between CHRNA5-CHRNA3-CHRNB4 nicotinic acetylcholine receptors and complete smoking cessation.Increasing evidence indicates that the genetic variant CHRNA5 predicts the response to smoking cessation medicine. The ability to quitting smoking is affected by genetic factors, including genetically based differences in the way nicotine is metabolized. In the CYP450 system there are 173 genetic variants, which impacts how quickly nicotine is metabolizes by each individual. The speed of metabolism impacts the regularity and quantity of nicotine used. For instance, in people who metabolize nicotine gradually their central nervous system effects of nicotine lasts longer, increasing their probability of dependence, but also increasing ability with quitting smoking.
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Effects of nicotine on human brain development
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Addiction and dependence
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Stimulation of the brain Nicotine is a parasympathomimetic stimulant that binds to and activates nicotinic acetylcholine receptors in the brain, which subsequently causes the release of dopamine and other neurotransmitters, such as norepinephrine, acetylcholine, serotonin, gamma-aminobutyric acid, glutamate, endorphins, and several neuropeptides, including proopiomelanocortin-derived α-MSH and adrenocorticotropic hormone. Corticotropin-releasing factor, Neuropeptide Y, orexins, and norepinephrine are involved in nicotine addiction.Continuous exposure to nicotine can cause an increase in the number of nicotinic receptors, which is believed to be a result of receptor desensitization and subsequent receptor upregulation. Long-term exposure to nicotine can also result in downregulation of glutamate transporter 1. Long-term nicotine exposure upregulates cortical nicotinic receptors, but it also lowers the activity of the nicotinic receptors in the cortical vasodilation region. These effects are not easily understood.With constant use of nicotine, tolerance occurs at least partially as a result of the development of new nicotinic acetylcholine receptors in the brain. After several months of nicotine abstinence, the number of receptors go back to normal. The extent to which alterations in the brain caused by nicotine use are reversible is not fully understood. Nicotine also stimulates nicotinic acetylcholine receptors in the adrenal medulla, resulting in increased levels of epinephrine and beta-endorphin. Its physiological effects stem from the stimulation of nicotinic acetylcholine receptors, which are located throughout the central and peripheral nervous systems.The α4β2 nicotinic receptor subtype is the main nicotinic receptor subtype. Nicotine activates brain receptors which produce sedative as well as pleasurable effects. Chronic nicotinic acetylcholine receptor activation from repeated nicotine exposure can induce strong effects on the brain, including changes in the brain's physiology, that result from the stimulation of regions of the brain associated with reward, pleasure, and anxiety. These complex effects of nicotine on the brain are still not well understood.Nicotine interferes with the blood–brain barrier function, and as a consequence raises the risk of brain edema and neuroinflammation. When nicotine enters the brain it stimulates, among other activities, the midbrain dopaminergic neurons situated in the ventral tegmental area and pars compacta. It induces the release of dopamine in different parts of the brain, such as the nucleus accumbens, amygdala, and hippocampus. Ghrelin-induced dopamine release occurs as a result of the activation of the cholinergic–dopaminergic reward link in the ventral tegmental area, a critical part of the reward areas in the brain related with reinforcement. Ghrelin signaling may affect the reinforcing effects of drug dependence.
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Effects of nicotine on human brain development
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Addiction and dependence
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Discontinuing nicotine use When nicotine intake stops, the upregulated nicotinic acetylcholine receptors induce withdrawal symptoms. These symptoms can include cravings for nicotine, anger, irritability, anxiety, depression, impatience, trouble sleeping, restlessness, hunger, weight gain, and difficulty concentrating. When trying to quit smoking with vaping a base containing nicotine, symptoms of withdrawal can include irritability, restlessness, poor concentration, anxiety, depression, and hunger. The changes in the brain cause a nicotine user to feel abnormal when not using nicotine. In order to feel normal, the user has to keep his or her body supplied with nicotine. E-cigarettes may reduce cigarette craving and withdrawal symptoms.Limiting tobacco consumption with the use of campaigns that portray cigarette smoking as unacceptable and harmful have been enacted; though, advocating for the use of e-cigarettes jeopardizes this because of the possibility of escalating nicotine addiction. It is not clear whether e-cigarette use will decrease or increase overall nicotine addiction, but the nicotine content in e-cigarettes is adequate to sustain nicotine dependence. Chronic nicotine use causes a broad range of neuroplastic adaptations, making quitting hard to accomplish.A 2015 study found that users vaping non-nicotine e-liquid exhibited signs of dependence. Experienced users tend to take longer puffs which may result in higher nicotine intake. It is difficult to assess the impact of nicotine dependence from e-cigarette use because of the wide range of e-cigarette products. The addiction potential of e-cigarettes may have risen because as they have progressed, they delivery nicotine better. A 2016 review states that "The highly addictive nature of nicotine is responsible for its widespread use and difficulty with quitting."
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Effects of nicotine on human brain development
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Young adults and youth
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Addiction and dependence E-cigarettes use by children and adolescents may result in nicotine addiction.: C : A Following the possibility of nicotine addiction via e-cigarettes, there is concern that children may start smoking cigarettes. Adolescents are likely to underestimate nicotine's addictiveness. Vulnerability to the brain-modifying effects of nicotine, along with youthful experimentation with e-cigarettes, could lead to a lifelong addiction. A long-term nicotine addiction from using a vape may result in using other tobacco products.The majority of addiction to nicotine starts during youth and young adulthood. Adolescents are more likely to become nicotine dependent than adults. The adolescent brain seems to be particularly sensitive to neuroplasticity as a result of nicotine. Minimal exposure could be enough to produce neuroplastic alterations in the very sensitive adolescent brain. Exposure to nicotine during adolescence may increase vulnerability to getting addicted to cocaine and other drugs.The ability of e-cigarettes to deliver comparable or higher amounts of nicotine compared to traditional cigarettes raises concerns about e-cigarette use generating nicotine dependence among young people. Youth who believe they are vaping without nicotine could still be inhaling nicotine because there are significant differences between declared and true nicotine content.A 2016 US Surgeon General report concluded that e-cigarette use among young adults and youths is of public health concern. Various organizations, including the International Union Against Tuberculosis and Lung Disease, the American Academy of Pediatrics, the American Cancer Society, the Centers for Disease Control and Prevention, and the US Food and Drug Administration (US FDA), have expressed concern that e-cigarette use could increase the prevalence of nicotine addiction in youth.: IUATLD : AAP : ACS : CDC : US FDA Flavored tobacco is especially enticing to youth, and certain flavored tobacco products increase addiction. There is concern that flavored e-cigarettes could have a similar impact on youth. The extent to which teens are using e-cigarettes may lead to addiction or substance dependence in youth, is unknown. A 2017 review noted that "adolescents experience symptoms of dependence at lower levels of nicotine exposure than adults. Consequently, it is harder to reverse addiction originating in this stage compared with later in life."Adolescents are particularly susceptible to nicotine addiction: the majority (90%) of smokers start before the age of 18, a fact that has been utilized by tobacco companies for decades in their teen-targeted advertising, marketing and even product design. E-cigarette marketing tactics have the possibility to glamorize smoking and enticing children and never smokers, even when such outcomes are unintended. Adolescents may show signs of dependence with even infrequent nicotine use; sustained nicotine exposure leads to upregulation of the receptors in the prefrontal cortex, pathways which are involved in cognitive control, and which are not fully matured until the mid-twenties. Such disruption of neural circuit development may lead to long-term cognitive and behavioral impairment and has been associated with depression and anxiety.The nicotine content in e-cigarettes varies widely by product and by use. Refill solutions may contain anywhere from 1.8% nicotine (18 mg/mL) to over 5% (59 mg/mL). Nicotine delivery may be affected by the device itself, for example, by increasing the voltage which changes the aerosol delivered, or by "dripping"—a process of inhaling liquid poured directly onto coils. The latest generation of e-cigarettes, "pod products," such as Juul, have the highest nicotine content (59 mg/mL), in protonated salt, rather than the free-base nicotine form found in earlier generations, which makes it easier for less experienced users to inhale. Despite the clear presence of nicotine in e-cigarettes, adolescents often do not recognize this fact, potentially fueling misperceptions about the health risks and addictive potential of e-cigarettes.In the US, the unprecedented increase in current (past-month) users from 11.7% of high school students in 2017 to 20.8% in 2018 would imply dependence, if not addiction, given what we know about nicotine and its effects on the adolescent brain. Two recent studies in 2018 utilized validated measures to identify nicotine dependence in e-cigarette using adolescents. Exposure to nicotine from certain types of e-cigarettes may be higher than that from traditional cigarettes. For example, in a study in 2018 of adolescent pod users, their urinary cotinine (a breakdown product used to measure nicotine exposure) levels were higher than levels seen in adolescent cigarette smokers.
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Effects of nicotine on human brain development
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Young adults and youth
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Effects on the brain Both preadolescence and adolescence are developmental periods associated with increased vulnerability to nicotine addiction, and exposure to nicotine during these periods may lead to long-lasting changes in behavioral and neuronal plasticity. Nicotine has more significant and durable damaging effects on adolescent brains compared to adult brains, the former suffering more harmful effects. Preclinical animal studies have shown that in rodent models, nicotinic acetylcholine receptor signaling is still actively changing during adolescence, with higher expression and functional activity of nicotinic acetylcholine receptors in the forebrain of adolescent rodents compared to their adult counterparts.In rodent models, nicotine actually enhances neuronal activity in several reward-related regions and does so more robustly in adolescents than in adults. This increased sensitivity to nicotine in the reward pathways of adolescent rats is associated with enhanced behavioral responses, such as strengthening the stimulus response reward for administration of nicotine. In conditioned place-preference tests—where reward is measured by the amount of time animals spend in an environment where they receive nicotine compared to an environment where nicotine is not administered—adolescent rodents have shown an increased sensitivity to the rewarding effects of nicotine at very low doses (0.03 mg/kg) and exhibited a unique vulnerability to oral self-administration during the early-adolescent period.Adolescent rodents also have shown higher levels of nicotine self-administration than adults, decreased sensitivity to the aversive effects of nicotine, and less prominent withdrawal symptoms following chronic nicotine exposure. This characteristic in rodent models of increased positive and decreased negative short-term effects of nicotine during adolescence (versus adulthood) highlights the possibility that human adolescents might be particularly vulnerable to developing dependency to and continuing to use e-cigarettes.The teen years are critical for brain development, which continues into young adulthood. Young people who use nicotine products in any form, including e-cigarettes, are uniquely at risk for long-lasting effects. Because nicotine affects the development of the brain's reward system, continued e-cigarette use can not only lead to nicotine addiction, but it also can make other drugs such as cocaine and methamphetamine more pleasurable to a teen's developing brain. Concerns exist in respect to adolescence vaping due to studies indicating nicotine may potentially have harmful effects on the brain. Nicotine exposure during adolescence adversely affects cognitive development.Children are more sensitive to nicotine than adults. The use of products containing nicotine in any form among youth, including in e-cigarettes, is unsafe. Animal research indicates strong evidence that the limbic system, which modulates drug reward, cognition, and emotion, is growing during adolescence and is particularly vulnerable to the long lasting effects of nicotine. In youth, nicotine is associated with cognitive impairment as well as the chance of getting addicted for life.The adolescent's developing brain is especially sensitive to the harmful effects of nicotine. A short period of regular or occasional nicotine exposure in adolescence exerts long-term neurobehavioral damage. Risks of exposing the developing brain to nicotine include mood disorders and permanent lowering of impulse control. The rise in vaping is of great concern because the parts encompassing in greater cognitive activities including the prefrontal cortex of the brain continues to develop into the 20s. Nicotine exposure during brain development may hamper growth of neurons and brain circuits, effecting brain architecture, chemistry, and neurobehavioral activity.Nicotine changes the way synapses are formed, which can harm the parts of the brain that control attention and learning. Preclinical studies indicate that teens being exposed to nicotine interferes with the structural development of the brain, inducing lasting alterations in the brain's neural circuits. Nicotine affects the development of brain circuits that control attention and learning. Other risks include mood disorders and permanent problems with impulse control—failure to fight an urge or impulse that may harm oneself or others. Each e-cigarette brand differs in the exact amount of ingredients and nicotine in each product. Therefore, little is known regarding the health consequences of each brand to the growing brains of youth.E-cigarettes are a source of potential developmental toxicants. E-cigarette aerosol, e-liquids, flavoring, and the metallic coil can cause oxidative stress, and the growing brain is uniquely susceptible to the detrimental effects of oxidative stress. As indicated in the limited research from animal studies, there is the potential for induced changes in neurocognitive growth among children who have been subjected to e-cigarette aerosols consisting of nicotine. The US FDA stated in 2019 that some people who use e-cigarettes have experienced seizures, with most reports involving youth or young adult users. Inhaling lead from e-cigarette aerosol can induce serious neurologic injury, notably to the growing brains of children.A 2017 review states that "Because the brain does not reach full maturity until the mid-20s, restricting sales of electronic cigarettes and all tobacco products to individuals aged at least 21 years and older could have positive health benefits for adolescents and young adults." Adverse effects to the health of children is mostly not known. Children subjected to e-cigarettes had a higher likelihood of having more than one adverse effect and effects were more significant, than with children subjected to traditional cigarettes. Significant harmful effects were cyanosis, nausea, and coma, among others.
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Effects of nicotine on human brain development
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Fetal development
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There is accumulating research concerning the negative effects of nicotine on prenatal brain development. Vaping during pregnancy can be harmful to the fetus. There is no supporting evidence demonstrating that vaping is safe for use in pregnant women. Nicotine accumulates in the fetus because it goes through the placenta. Nicotine has been found in placental tissue as early as seven weeks of embryonic gestation, and nicotine concentrations are higher in fetal fluids than in maternal fluids. Nicotine can lead to vasoconstriction of uteroplacental vessels, reducing the delivery of both nutrients and oxygen to the fetus.As a result, nutrition is re-distributed to prioritize vital organs, such as the heart and the brain, at the cost of less vital organs, such as the liver, kidneys, adrenal glands, and pancreas, leading to underdevelopment and functional disorders later in life. Nicotine attaches to nicotinic acetylcholine receptors in the fetus brain. The stage when the human brain is developing is possibly the most sensitive time period to the effects of nicotine. When the brain is being developed, activating or desensitizing nicotinic acetylcholine receptors by being exposed to nicotine can result in long-term developmental disturbances.Prenatal nicotine exposure has been associated with dysregulation of catecholaminergic, serotonergic, and other neurotransmitter systems. Prenatal nicotine exposure is associated with preterm birth, stillbirth, sudden infant death syndrome, auditory processing complications, changes to the corpus callosum, changes in brain metabolism, changes in neurological systems, changes in neurotransmitter systems, changes in normal brain development, lower birth weights compared to other infants, and a reduction in brain weight.A 2017 review states, "because nicotine targets the fetal brain, damage can be present, even when birth weight is normal." A 2014 US Surgeon General report found "that nicotine adversely affects maternal and fetal health during pregnancy, and that exposure to nicotine during fetal development has lasting adverse consequences for brain development." Nicotine prenatal exposure is associated with behavioral abnormalities in adults and children. Prenatal nicotine exposure may result in persisting, multigenerational changes in the epigenome.
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Effects of nicotine on human brain development
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Effects of e-cigarette liquid
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E-liquid exposure whether intentional or unintentional from ingestion, eye contact, or skin contact can cause adverse effects such as seizures and anoxic brain trauma. The nicotine in e-liquids readily absorbs into the bloodstream when a person uses an e-cigarette. Upon entering the blood, nicotine stimulates the adrenal glands to release the hormone epinephrine. Epinephrine stimulates the central nervous system and increases blood pressure, breathing, and heart rate.As with most addictive substances, nicotine increases levels of a chemical messenger in the brain called dopamine, which affects parts of the brain that control reward (pleasure from natural behaviors such as eating). These feelings motivate some people to use nicotine again and again, despite possible risks to their health and well-being.A 2015 study on the offspring of the pregnant mice, which were exposed to nicotine-containing e-liquid, showed significant behavioral alterations. This indicated that exposure to e-cigarette components in a susceptible time period of brain development could induce persistent behavioral changes. E-cigarette aerosols without containing nicotine could harm the growing conceptus. This indicates that the ingredients in the e-liquid, such as the flavors, could be developmental toxicants.
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GB virus C
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GB virus C
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GB virus C (GBV-C), formerly known as hepatitis G virus (HGV) and also known as human pegivirus – HPgV is a virus in the family Flaviviridae and a member of the Pegivirus, is known to infect humans, but is not known to cause human disease. Reportedly, HIV patients coinfected with GBV-C can survive longer than those without GBV-C, but the patients may be different in other ways. Research is active into the virus' effects on the immune system in patients coinfected with GBV-C and HIV.
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GB virus C
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Human infection
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The majority of immunocompetent individuals clear GBV-C viraemia, but in some individuals, infection persists for decades. However, the time interval between GBV-C infection and clearance of viraemia (detection of GBV-C RNA in plasma) is not known.
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GB virus C
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Human infection
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About 2% of healthy US blood donors are viraemic with GBV-C, and up to 13% of blood donors have antibodies to E2 protein, indicating possible prior infection.Parenteral, sexual, and vertical transmissions of GBV-C have been documented. Because of shared modes of transmission, individuals infected with HIV are often coinfected with GBV-C; the prevalence of GBV-C viraemia in HIV patients ranges from 14 to 43%.Several but not all studies have suggested that coinfection with GBV-C slows the progression of HIV disease. In vitro models also demonstrated that GBV-C slows HIV replication. This beneficial effect may be related to action of several GBV-C viral proteins, including NS5A phosphoprotein and E2 envelope protein.
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GB virus C
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Virology
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It has a single-stranded, positive-sense RNA genome of about 9.3 kb and contains a single open reading frame (ORF) encoding two structural (E1 and E2) and five nonstructural (NS2, NS3, NS4, NS5A, and NS5B) proteins. GB-C virus does not appear to encode a C (core or nucleocapsid) protein like, for instance, hepatitis C virus. Nevertheless, viral particles have been found to have a nucleocapsid. The source of the nucleocapsid protein remains unknown.
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GB virus C
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Virology
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Taxonomy GBV-C is a member of the family Flaviviridae and is phylogenetically related to hepatitis C virus, but replicates primarily in lymphocytes, and poorly, if at all, in hepatocytes. GBV-A and GBV-B are probably tamarin viruses, while GBV-C infects humans. The GB viruses have been tentatively assigned to a fourth genus within the Flaviviridae named "Pegivirus", but this has yet to be formally endorsed by the International Committee on Taxonomy of Viruses.Another member of this clade, GBV-D, has been isolated from a bat (Pteropus giganteus). GBV-D may be ancestral to GBV-A and GBV-C.The mutation rate of the GBV-C genome has been estimated at 10−2 to 10−3 substitutions/site/year.
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GB virus C
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Epidemiology
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GBV-C infection has been found worldwide and currently infects around a sixth of the world's population. High prevalence is observed among subjects with the risk of parenteral exposures, including those with exposure to blood and blood products, those on hemodialysis, and intravenous drug users. Sexual contact and vertical transmission may occur. About 10–25% of hepatitis C-infected patients and 14–36% of drug users who are seropositive for HIV-1 show the evidence of GBV-C infection.
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GB virus C
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Epidemiology
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It has been classified into seven genotypes and many subtypes with distinct geographical distributions. Genotypes 1 and 2 are prevalent in Northern and Central Africa and in Americas. Genotypes 3 and 4 are commons in Asia. Genotype 5 is present in Central and Southern Africa. Genotype 6 can be encountered in Southeast Asia. Finally, genotype 7 has been reported in China. Infection with multiple genotypes is possible.Genotype 5 appears to be basal in the phylogenetic tree, suggesting an African origin for this virus.
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GB virus C
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History
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Hepatitis G virus and GB virus C (GBV-C) are RNA viruses that were independently identified in 1995, and were subsequently found to be two isolates of the same virus. Although GBV-C was initially thought to be associated with chronic hepatitis, extensive investigation failed to identify any association between this virus and any clinical illness. GB Virus C (and indeed, GBV-A and GBV-B) is named after the surgeon, G. Barker, who fell ill in 1966 with a non-A non-B hepatitis which at the time was thought to have been caused by a new, infectious hepatic virus.
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Molecule-based magnets
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Molecule-based magnets
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Molecule-based magnets (MBMs) or molecular magnets are a class of materials capable of displaying ferromagnetism and other more complex magnetic phenomena. This class expands the materials properties typically associated with magnets to include low density, transparency, electrical insulation, and low-temperature fabrication, as well as combine magnetic ordering with other properties such as photoresponsiveness. Essentially all of the common magnetic phenomena associated with conventional transition-metal magnets and rare-earth magnets can be found in molecule-based magnets. Prior to 2011, MBMs were seen to exhibit "magnetic ordering with Curie temperature (Tc) exceeding room temperature".
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Molecule-based magnets
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History
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The first synthesis and characterization of MBMs was accomplished by Wickman and co-workers in 1967. This was a diethyldithiocarbamate-Fe(III) chloride compound.In February 1992, Gatteschi and Sessoli published on MBMs with particular attention to the fabrication of systems in which stable organic radicals are coupled to metal ions. At that date, the highest Tc on record was measured by SQUID magnetometer as 30K.The field exploded in 1996 with the publication of a book on "Molecular Magnetism: From Molecular Assemblies to the Devices".In February 2007, de Jong et al. grew thin-film TCNE MBM in situ, while in September 2007, photoinduced magnetism was demonstrated in a TCNE organic-based magnetic semiconductor.The June 2011 issue of Chemical Society Reviews was devoted to MBMs. In the editorial, written by Miller and Gatteschi, are mentioned TCNE and above-room-temperature magnetic ordering along with many other unusual properties of MBMs.
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Molecule-based magnets
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Theory
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The mechanism by which molecule-based magnets stabilize and display a net magnetic moment is different than that present in traditional metal- and ceramic-based magnets. For metallic magnets, the unpaired electrons align through quantum mechanical effects (termed exchange) by virtue of the way in which the electrons fill the orbitals of the conductive band. For most oxide-based ceramic magnets, the unpaired electrons on the metal centers align via the intervening diamagnetic bridging oxide (termed superexchange). The magnetic moment in molecule-based magnets is typically stabilized by one or more of three main mechanisms: Through space or dipolar coupling Exchange between orthogonal (non-overlapping) orbitals in the same spatial region Net moment via antiferromagnetic coupling of non-equal spin centers (ferrimagnetism)In general, molecule-based magnets tend to be of low dimensionality. Classic magnetic alloys based on iron and other ferromagnetic materials feature metallic bonding, with all atoms essentially bonded to all nearest neighbors in the crystal lattice. Thus, critical temperatures at which point these classical magnets cross over to the ordered magnetic state tend to be high, since interactions between spin centers is strong. Molecule-based magnets, however, have spin bearing units on molecular entities, often with highly directional bonding. In some cases, chemical bonding is restricted to one dimension (chains). Thus, interactions between spin centers are also limited to one dimension, and ordering temperatures are much lower than metal/alloy-type magnets. Also, large parts of the magnetic material are essentially diamagnetic, and contribute nothing to the net magnetic moment.
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Molecule-based magnets
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Applications
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In 2015 oxo-dimeric Fe(salen)-based magnets ("anticancer nanomagnets") in a water suspension were shown to demonstrate intrinsic room temperature ferromagnetic behavior, as well as antitumor activity, with possible medical applications in chemotherapy, magnetic drug delivery, magnetic resonance imaging (MRI), and magnetic field-induced local hyperthermia therapy.
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Molecule-based magnets
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Background
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Molecule-based magnets comprise a class of materials which differ from conventional magnets in one of several ways. Most traditional magnetic materials are comprised purely of metals (Fe, Co, Ni) or metal oxides (CrO2) in which the unpaired electrons spins that contribute to the net magnetic moment reside only on metal atoms in d- or f-type orbitals.In molecule-based magnets, the structural building blocks are molecular in nature. These building blocks are either purely organic molecules, coordination compounds or a combination of both. In this case, the unpaired electrons may reside in d or f orbitals on isolated metal atoms, but may also reside in highly localized s and p orbitals as well on the purely organic species. Like conventional magnets, they may be classified as hard or soft, depending on the magnitude of the coercive field.Another distinguishing feature is that molecule-based magnets are prepared via low-temperature solution-based techniques, versus high-temperature metallurgical processing or electroplating (in the case of magnetic thin films). This enables a chemical tailoring of the molecular building blocks to tune the magnetic properties.Specific materials include purely organic magnets made of organic radicals for example p-nitrophenyl nitronyl nitroxides, decamethylferrocenium tetracyanoethenide, mixed coordination compounds with bridging organic radicals, Prussian blue related compounds, and charge-transfer complexes.Molecule-based magnets derive their net moment from the cooperative effect of the spin-bearing molecular entities, and can display bulk ferromagnetic and ferrimagnetic behavior with a true critical temperature. In this regard, they are contrasted with single-molecule magnets, which are essentially superparamagnets (displaying a blocking temperature versus a true critical temperature). This critical temperature represents the point at which the materials switches from a simple paramagnet to a bulk magnet, and can be detected by ac susceptibility and specific heat measurements.
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Transcriptor
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Transcriptor
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A transcriptor is a transistor-like device composed of DNA and RNA rather than a semiconducting material such as silicon. Prior to its invention in 2013, the transcriptor was considered an important component to build biological computers.
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Transcriptor
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Background
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To function, a modern computer needs three different capabilities: It must be able to store information, transmit information between components, and possess a basic system of logic. Prior to March 2013, scientists had successfully demonstrated the ability to store and transmit data using biological components made of proteins and DNA. Simple two-terminal logic gates had been demonstrated, but required multiple layers of inputs and thus were impractical due to scaling difficulties.
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Transcriptor
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Invention and description
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On March 28, 2013, a team of bioengineers from Stanford University led by Drew Endy announced that they had created the biological equivalent of a transistor, which they named a "transcriptor". That is, they created a three-terminal device with a logic system that can control other components. The transcriptor regulates the flow of RNA polymerase across a strand of DNA using special combinations of enzymes to control movement. According to project member Jerome Bonnet, "The choice of enzymes is important. We have been careful to select enzymes that function in bacteria, fungi, plants and animals, so that bio-computers can be engineered within a variety of organisms."Transcriptors can replicate traditional AND, OR, NOR, NAND, XOR, and XNOR gates with equivalents, which Endy dubbed "Boolean Integrase Logic (BIL) gates", in a single-layer process (i.e., without requiring multiple instances of the simpler gates to build up more complex ones). Like a traditional transistor, a transcriptor can amplify an input signal. A group of transcriptors can do almost any type of computing, including counting and comparison.
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Transcriptor
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Impact
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Stanford dedicated the BIL gate's design to the public domain, which may speed its adoption. According to Endy, other researchers were already using the gates to reprogram metabolism when the Stanford team published its research.Computing by transcriptor is still very slow; it can take a few hours between receiving an input signal and generating an output. Endy doubted that biocomputers would ever be as fast as traditional computers, but added that is not the goal of his research. "We're building computers that will operate in a place where your cellphone isn't going to work", he said. Medical devices with built-in biological computers could monitor, or even alter, cell behavior from inside a patient's body. ExtremeTech writes: Moving forward, though, the potential for real biological computers is immense. We are essentially talking about fully-functional computers that can sense their surroundings, and then manipulate their host cells into doing just about anything. Biological computers might be used as an early-warning system for disease, or simply as a diagnostic tool ... Biological computers could tell their host cells to stop producing insulin, to pump out more adrenaline, to reproduce some healthy cells to combat disease, or to stop reproducing if cancer is detected. Biological computers will probably obviate the use of many pharmaceutical drugs.
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Transcriptor
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Impact
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UC Berkeley biochemical engineer Jay Keasling said the transcriptor "clearly demonstrates the power of synthetic biology and could revolutionize how we compute in the future".
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Turning point test
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Turning point test
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In statistical hypothesis testing, a turning point test is a statistical test of the independence of a series of random variables. Maurice Kendall and Alan Stuart describe the test as "reasonable for a test against cyclicity but poor as a test against trend." The test was first published by Irénée-Jules Bienaymé in 1874.
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Turning point test
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Statement of test
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The turning point tests the null hypothesis H0: X1, X2, ..., Xn are independent and identically distributed random variables (iid)against H1: X1, X2, ..., Xn are not iid.
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Turning point test
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Statement of test
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Test statistic We say i is a turning point if the vector X1, X2, ..., Xi, ..., Xn is not monotonic at index i. The number of turning points is the number of maxima and minima in the series.Letting T be the number of turning points then for large n, T is approximately normally distributed with mean (2n − 4)/3 and variance (16n − 29)/90. The test statistic 16 29 90 is approximately standard normal for large values of n.
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Turning point test
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Applications
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The test can be used to verify the accuracy of a fitted time series model such as that describing irrigation requirements.
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Β-Methyl-2C-B
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Β-Methyl-2C-B
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β-Methyl-2C-B (BMB) is a recreational designer drug with psychedelic effects. It is a structural isomer of DOB but is considerably less potent, having around half the potency of 2C-B itself with activity starting at a dosage of around 20 mg. It has two possible enantiomers but their activity has not been tested separately.
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Iron(II) iodide
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Iron(II) iodide
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Iron(II) iodide is an inorganic compound with the chemical formula FeI2. It is used as a catalyst in organic reactions.
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Iron(II) iodide
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Preparation
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Iron(II) iodide can be synthesised from the elements, i.e. by the reaction of iron with iodine.
Fe + I2 → FeI2This is in contrast to the other iron(II) halides, which are best prepared by reaction of heated iron with the appropriate hydrohalic acid.
Fe + 2HX → FeX2 + H2In contrast to the ferrous fluoride, chloride and bromide, which form known hydrates, the diiodide is speculated to form a stable tetrahydrate but it not been characterized directly.
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Iron(II) iodide
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Structure
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Iron(II) iodide adopts the same crystal structure as cadmium iodide (CdI2).
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Iron(II) iodide
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Reactions
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Iron(II) iodide dissolves in water. Dissolving iron metal in hydroiodic acid is another route to aqueous solutions of iron(II) iodide. Crystalline hydrates precipitate from these solutions.
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Romantic realism
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Romantic realism
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Romantic realism is art that combines elements of both romanticism and realism. The terms "romanticism" and "realism" have been used in varied ways, and are sometimes seen as opposed to one another.
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Romantic realism
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In literature and art
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The term has long standing in literary criticism. For example, Joseph Conrad's relationship to romantic realism is analyzed in Ruth M. Stauffer's 1922 book Joseph Conrad: His Romantic Realism. Liam O'Flaherty's relationship to romantic realism is discussed in P.F. Sheeran's book The Novels of Liam O'Flaherty: A Study in Romantic Realism. Fyodor Dostoyevsky is described as a romantic realist in Donald Fanger's book, Dostoevsky and Romantic Realism: A Study of Dostoevsky in Relation to Balzac, Dickens, and Gogol. Historian Jacques Barzun argued that romanticism was falsely opposed to realism and declared that "...the romantic realist does not blink his weakness, but exerts his power."The term also has long standing in art criticism. Art scholar John Baur described it as "a form of realism modified to express a romantic attitude or meaning". According to Theodor W. Adorno, the term "romantic realism" was used by Joseph Goebbels to define the official doctrine of the art produced in Nazi Germany, although this usage did not achieve wide currency.In 1928 Anatoly Lunacharsky, People's Commissar for Education of the Soviet Union, wrote: The proletariat will introduce a strong romantic-realist current into all art. Romantic, because it is full of aspirations and is not yet a complete class, so that the mighty content of its culture cannot yet find an appropriate framework for itself; realistic insofar as Plekhanov noted, insofar as the class that intends to build here on earth and is imbued with deep faith in such construction is intimately connected with reality as it is.
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Romantic realism
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In literature and art
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Novelist and philosopher Ayn Rand described herself as a romantic realist, and many followers of Objectivism who work in the arts apply this term to themselves. As part of her aesthetics, Rand defined romanticism as a "category of art based on the recognition of the principle that man possesses the faculty of volition", a realm of heroes and villains, which she contrasted to Naturalism. She wanted her art to be portrayal of life "as it could be and should be". She wrote: "The method of romantic realism is to make life more beautiful and interesting than it actually is, yet give it all the reality, and even a more convincing reality than that of our everyday existence." Her definition did not limit itself to the positive though. She considered Dostoyevsky to be a Romantic Realist too.
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Romantic realism
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In music
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"Realism" in music is often associated with the use of music for the depiction of objects, whether they be real (as in Bedřich Smetana's "Peasant Wedding" of Die Moldau) or mythological (as in Richard Wagner's Ring cycle). Musicologist Richard Taruskin discusses what he calls the "black romanticism" of Niccolò Paganini and Franz Liszt, i.e., the development and use of musical techniques that can be used to depict or suggest "grotesque" creatures or objects, such as the "laugh of the devil", to create a "frightening atmosphere". Thus, Taruskin's "black romanticism" is a form of "romantic realism" deployed by nineteenth-century virtuosi with the intent of invoking fear or "the sublime".
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Romantic realism
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In music
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In the nineteenth-century, historians traditionally associate romantic realism with the works of Richard Wagner. It featured settings that are claimed to have historical accuracy in accordance with the prevailing myth of realism. These works formed part of Wagner's notion based on aesthetic realism called the "invisible theater", which sought to create the fullest illusion of reality inside the theater.There are scholars who also identify musicians such as Hector Berlioz and Franz Liszt as romantic realists. Liszt was noted for his romantic realism, free tonality, and program-music as an adherent of the New German School. Historians also cite how totalitarian dictators choose romantic realism as the music for the masses. It is said that Adolf Hitler favored Parsifal while Joseph Stalin liked Wofgang Amadeus Mozart's piano concertos.
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Population viability analysis
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Population viability analysis
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Population viability analysis (PVA) is a species-specific method of risk assessment frequently used in conservation biology.
It is traditionally defined as the process that determines the probability that a population will go extinct within a given number of years.
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Population viability analysis
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Population viability analysis
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More recently, PVA has been described as a marriage of ecology and statistics that brings together species characteristics and environmental variability to forecast population health and extinction risk. Each PVA is individually developed for a target population or species, and consequently, each PVA is unique. The larger goal in mind when conducting a PVA is to ensure that the population of a species is self-sustaining over the long term.
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Population viability analysis
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Uses
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Population viability analysis (PVA) is used to estimate the likelihood of a population’s extinction and indicate the urgency of recovery efforts, and identify key life stages or processes that should be the focus of recovery efforts. PVA is also used to identify factors that drive population dynamics, compare proposed management options and assess existing recovery efforts. PVA is frequently used in endangered species management to develop a plan of action, rank the pros and cons of different management scenarios, and assess the potential impacts of habitat loss.
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Population viability analysis
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History
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In the 1970s, Yellowstone National Park was the centre of a heated debate over different proposals to manage the park’s problem grizzly bears (Ursus arctos). In 1978, Mark Shaffer proposed a model for the grizzlies that incorporated random variability, and calculated extinction probabilities and minimum viable population size. The first PVA is credited to Shaffer.PVA gained popularity in the United States as federal agencies and ecologists required methods to evaluate the risk of extinction and possible outcomes of management decisions, particularly in accordance with the Endangered Species Act of 1973, and the National Forest Management Act of 1976.
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Population viability analysis
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History
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In 1986, Gilpin and Soulé broadened the PVA definition to include the interactive forces that affect the viability of a population, including genetics.
The use of PVA increased dramatically in the late 1980s and early 1990s following advances in personal computers and software packages.
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Population viability analysis
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Examples
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The endangered Fender's blue butterfly (Icaricia icarioides) was recently assessed with a goal of providing additional information to the United States Fish and Wildlife Service, which was developing a recovery plan for the species. The PVA concluded that the species was more at risk of extinction than previously thought and identified key sites where recovery efforts should be focused. The PVA also indicated that because the butterfly populations fluctuate widely from year to year, to prevent the populations from going extinct the minimum annual population growth rate must be kept much higher than at levels typically considered acceptable for other species.Following a recent outbreak of canine distemper virus, a PVA was performed for the critically endangered island fox (Urocyon littoralis) of Santa Catalina Island, California. The Santa Catalina island fox population is uniquely composed of two subpopulations that are separated by an isthmus, with the eastern subpopulation at greater risk of extinction than the western subpopulation. PVA was conducted with the goals of 1) evaluating the island fox’s extinction risk, 2) estimating the island fox’s sensitivity to catastrophic events, and 3) evaluating recent recovery efforts which include release of captive-bred foxes and transport of wild juvenile foxes from the west to the east side. Results of the PVA concluded that the island fox is still at significant risk of extinction, and is highly susceptible to catastrophes that occur more than once every 20 years. Furthermore, extinction risks and future population sizes on both sides of the island were significantly dependent on the number of foxes released and transported each year.PVAs in combination with sensitivity analysis can also be used to identify which vital rates has the relative greatest effect on population growth and other measures of population viability. For example, a study by Manlik et al. (2016) forecast the viability of two bottlenose dolphin populations in Western Australia and identified reproduction as having the greatest influence on the forecast of these populations. One of the two populations was forecast to be stable, whereas the other population was forecast to decline, if it isolated from other populations and low reproductive rates persist. The difference in viability between the two studies was primarily due to differences in reproduction and not survival. The study also showed that temporal variation in reproduction had a greater effect on population growth than temporal variation in survival.
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Population viability analysis
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Controversy
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Debates exist and remain unresolved over the appropriate uses of PVA in conservation biology and PVA’s ability to accurately assess extinction risks.
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Population viability analysis
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Controversy
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A large quantity of field data is desirable for PVA; some conservatively estimate that for a precise extinction probability assessment extending T years into the future, five-to-ten times T years of data are needed. Datasets of such magnitude are typically unavailable for rare species; it has been estimated that suitable data for PVA is available for only 2% of threatened bird species. PVA for threatened and endangered species is particularly a problem as the predictive power of PVA plummets dramatically with minimal datasets. Ellner et al. (2002) argued that PVA has little value in such circumstances and is best replaced by other methods. Others argue that PVA remains the best tool available for estimations of extinction risk, especially with the use of sensitivity model runs.
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Population viability analysis
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Controversy
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Even with an adequate dataset, it is possible that a PVA can still have large errors in extinction rate predictions. It is impossible to incorporate all future possibilities into a PVA: habitats may change, catastrophes may occur, new diseases may be introduced. PVA utility can be enhanced by multiple model runs with varying sets of assumptions including the forecast future date. Some prefer to use PVA always in a relative analysis of benefits of alternative management schemes, such as comparing proposed resource management plans.
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Population viability analysis
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Controversy
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Accuracy of PVAs has been tested in a few retrospective studies. For example, a study comparing PVA model forecasts with the actual fate of 21 well-studied taxa, showed that growth rate projections are accurate, if input variables are based on sound data, but highlighted the importance of understanding density-dependence (Brook et al. 2000). Also, McCarthey et al. (2003) showed that PVA predictions are relatively accurate, when they are based on long-term data. Still, the usefulness of PVA lies more in its capacity to identify and assess potential threats, than in making long-term, categorical predictions (Akçakaya & Sjögren-Gulve 2000).
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Population viability analysis
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Future directions
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Improvements to PVA likely to occur in the near future include: 1) creating a fixed definition of PVA and scientific standards of quality by which all PVA are judged and 2) incorporating recent genetic advances into PVA.
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2,5-Dimethylhexane
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2,5-Dimethylhexane
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2,5-Dimethylhexane is a branched alkane used in the aviation industry in low revolutions per minute helicopters. As an isomer of octane, the boiling point is very close to that of octane, but can in pure form be slightly lower. 2,5-Dimethylhexane is moderately toxic.
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Magnetic Resonance Imaging (journal)
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Magnetic Resonance Imaging (journal)
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Magnetic Resonance Imaging is a peer-reviewed scientific journal published by Elsevier, encompassing biology, physics, and clinical science as they relate to the development and use of magnetic resonance imaging technology. Magnetic Resonance Imaging was established in 1982 and the current editor-in-chief is John C. Gore. The journal produces 10 issues per year.
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Borland Turbo Debugger
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Borland Turbo Debugger
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Turbo Debugger (TD) is a machine-level debugger for DOS executables, intended mainly for debugging Borland Turbo Pascal, and later Turbo C programs, sold by Borland. It is a full-screen debugger displaying both Turbo Pascal or Turbo C source and corresponding assembly-language instructions, with powerful capabilities for setting breakpoints, watching the execution of instructions, monitoring machine registers, etc. Turbo Debugger can be used for programs not generated by Borland compilers, but without showing source statements; it is by no means the only debugger available for non-Borland executables, and not a significant general-purpose debugger.
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Borland Turbo Debugger
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Borland Turbo Debugger
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Although Borland's Turbo Pascal has useful single-stepping and conditional breakpoint facilities, the need for a more powerful debugger became apparent when Turbo Pascal started to be used for serious development.
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Borland Turbo Debugger
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Borland Turbo Debugger
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Initially, a separate company, TurboPower Software, produced a debugger, T-Debug, and also their Turbo Analyst and Overlay Manager for Turbo Pascal for versions 1 to 3. TurboPower released T-Debug Plus 4.0 for Turbo Pascal 4.0 in 1988, but by then Borland's Turbo Debugger had been announced.The original Turbo Debugger was sold as a stand-alone product introduced in 1989, along with Turbo Assembler and the second version of Turbo C.
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Borland Turbo Debugger
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Borland Turbo Debugger
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To use Turbo Debugger with source display, programs, or relevant parts of programs, must be compiled with Turbo Pascal or Turbo C with a conditional directive set to add debugging information to the compiled executable, with related source statements and corresponding machine code. The debugger can then be started (Turbo Debugger does not debug within the development IDE). After debugging the program can be recompiled without debugging information to reduce its size.
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Borland Turbo Debugger
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Borland Turbo Debugger
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Later Turbo Debugger, the stand-alone Turbo Assembler (TASM), and Turbo Profiler were included with the compilers in the professional Borland Pascal and Borland C++ versions of the more restricted Turbo Pascal and Turbo C++ suites for DOS. After the popularity of Microsoft Windows ended the era of DOS software development, Turbo Debugger was bundled with TASM for low-level software development. For many years after the end of the DOS era, Borland supplied Turbo Debugger with the last console-mode Borland C++ application development environment, version 5, and with Turbo Assembler 5.0. For many years both of these products were sold even though active development stopped on them. With Borland's reorganization of their development tools as CodeGear, all references to Borland C++ and Turbo Assembler vanished from their web site. The debuggers in later products such as C++Builder and Delphi are based on the Windows debugger introduced with the first Borland C++ and Pascal versions for Windows.
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Borland Turbo Debugger
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Borland Turbo Debugger
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The final version of Turbo Debugger came with several versions of the debugger program: TD.EXE was the basic debugger; TD286.EXE runs in protected mode, and TD386.EXE is a virtual debugger which uses the TDH386.SYS device driver to communicate with TD.EXE. The TDH386.SYS driver also adds breakpoints supported in hardware by the 386 and later processors to all three debugger programs. TD386 allows some extra breakpoints that the other debuggers of the era do not (I/O access breaks, ranges greater than 16 bytes, and so on). There is also a debugger for Windows 3 (TDW.EXE). Remote debugging was supported.
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Borland Turbo Debugger
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Reception
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BYTE in 1989 listed Turbo Debugger as among the "Distinction" winners of the BYTE Awards. Praising its ease of use and integration with Turbo Pascal and Turbo C, the magazine described it as "a programmer's Swiss army knife".
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Borland Turbo Debugger
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Turbo Debugger and emulation
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Various versions of Turbo Assembler, spanning from version 1.0 through 5.0, have been reported to run on the DOSBox emulator, which emulates DOS 5.0.
The last DOS release of TD.EXE, version 3.2, runs successfully in the 32-bit Windows XP NTVDM (i.e., in a DOS window, invoked with CMD.EXE), but TD286.EXE and TD386.EXE do not. Hardware breakpoints supported by the 386 and later processors are available if TDH386.SYS is loaded by including "DEVICE=<path>TDH386.SYS" in a CONFIG.NT file invoked when running TD.EXE.
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N-methylhydantoinase (ATP-hydrolysing)
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N-methylhydantoinase (ATP-hydrolysing)
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In enzymology, a N-methylhydantoinase (ATP-hydrolysing) (EC 3.5.2.14) is an enzyme that catalyzes the chemical reaction ATP + N-methylimidazolidine-2,4-dione + 2 H2O ⇌ ADP + phosphate + N-carbamoylsarcosineThe 3 substrates of this enzyme are ATP, N-methylimidazolidine-2,4-dione, and H2O, whereas its 3 products are ADP, phosphate, and N-carbamoylsarcosine.
This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in cyclic amides. The systematic name of this enzyme class is N-methylimidazolidine-2,4-dione amidohydrolase (ATP-hydrolysing). Other names in common use include N-methylhydantoin amidohydrolase, methylhydantoin amidase, N-methylhydantoin hydrolase, and N-methylhydantoinase. This enzyme participates in arginine, creatinine, and proline metabolism.
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Neo-futurism
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Neo-futurism
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Neo-futurism is a late-20th to early-21st-century movement in the arts, design, and architecture.Described as an avant-garde movement, as well as a futuristic rethinking of the thought behind aesthetics and functionality of design in growing cities, the movement has its origins in the mid-20th-century structural expressionist work of architects such as Alvar Aalto and Buckminster Fuller.Futurist architecture began in the 20th century starting with styles such as Art Deco and later with the Googie movement as well as high-tech architecture.
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Neo-futurism
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Origins
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Beginning in the late 1960s and early 1970s by architects such as Buckminster Fuller and John C. Portman Jr.; architect and industrial designer Eero Saarinen, Archigram, an avant-garde architectural group (Peter Cook, Warren Chalk, Ron Herron, Dennis Crompton, Michael Webb and David Greene, Jan Kaplický and others); it is considered in part an evolution out of high-tech architecture, developing many of the same themes and ideas.Although it was never built, the Fun Palace (1961), interpreted by architect Cedric Price as a "giant neo-futurist machine", influenced other architects, notably Richard Rogers and Renzo Piano, whose Centre Pompidou extended many of Price's ideas.
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Neo-futurism
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Definition
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Neo-futurism was in part revitalised in 2007 after the publication of "The Neo-Futuristic City Manifesto" included in the candidature presented to the Bureau International des Expositions (BIE) and written by innovation designer Vito Di Bari (a former executive director at UNESCO), to outline his vision for the city of Milan at the time of the Universal Expo 2015. Di Bari defined his neo-futuristic vision as the "cross-pollination of art, cutting edge technologies and ethical values combined to create a pervasively higher quality of life"; he referenced the Fourth Pillar of Sustainable Development Theory and reported that the name had been inspired by the United Nations report Our Common Future.Soon after Di Bari's manifesto, a collective in the UK called The Neo-Futurist Collective, launched their own version of the Neo-futurist manifesto, written by Rowena Easton, on the streets of Brighton on 20 February 2008, to mark the 99th anniversary of the publication of the Futurist manifesto by FT Marinetti in 1909. The collective's take on Neo-Futurism was much different to Di Bari's, in a sense that it focussed on acknowledging the legacy of the Italian Futurists as well as criticising our current state of despair over climate change and the financial system. On their introduction to their manifesto, The Neo-Futurist Collective noted: “In an age of mass despair over the state of the planet and the financial system, the futurist legacy of optimism for the power of technology uniting with the imagination of humanity has a powerful resonance for our modern age”. This shows an interpretation of Neo-Futurism that is more socially involved – one that speaks directly to its followers rather than denoting certain outlooks through actions (e.g. choice of eco-aware materials in Neo-Futurist architecture).
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Neo-futurism
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Definition
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Jean-Louis Cohen has defined neo-futurism as a corollary to technology, noting that a large amount of the structures built today are byproducts of new materials and concepts about the function of large-scale constructions in society. Etan J. Ilfeld wrote that in the contemporary neo-futurist aesthetic "the machine becomes an integral element of the creative process itself, and generates the emergence of artistic modes that would have been impossible prior to computer technology." Reyner Banham's definition of "une architecture autre" is a call for an architecture that technologically overcomes all previous architectures but possessing an expressive form, as Banham stated about neo-futuristic "Archigram's Plug-in Computerized City, form does not have to follow function into oblivion."Matthew Phillips defined the Neo-Futurist aesthetic as a "manipulation of time, space, and subject against a backdrop of technological innovation and domination, [that] posits new approaches to the future contrary to those of past avant-gardes and current technocratic philosophies". This definition agrees with the work of Neo-Futurist architects whose approach is situated in the context of technological innovation, but does not mention the ecological mindfulness that stems from architectural Neo-Futurism.
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Neo-futurism
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In art and architecture
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Neo-futurism was inspired partly by Futurist architect Antonio Sant'Elia and pioneered from the early 1960s and the late 1970s by Hal Foster, with architects such as William Pereira, Charles Luckman and Henning Larsen.
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