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Microcirculation Regulation Microcirculation > Function > Regulation The regulation of tissue perfusion occurs in microcirculation. There, arterioles control the flow of blood to the capillaries. Arterioles contract and relax, varying their diameter and vascular tone, as the vascular smooth muscle responds to diverse stimuli. Distension of the vessels due to increased blood pressure is a fundamental stimulus for muscle contraction in arteriolar walls.
Concrete mixing plant Prestressed structures Continuous_pour_concrete > Construction with concrete > Prestressed structures After the concrete has gained strength, tendons are pulled through the ducts and stressed. The ducts are then filled with grout. Bridges built in this way have experienced considerable corrosion of the tendons, so external post-tensioning may now be used in which the tendons run along the outer surface of the concrete.
Scale-invariant feature transform Scale-space extrema detection Scale-invariant_feature_transform > Algorithm > Scale-space extrema detection For scale space extrema detection in the SIFT algorithm, the image is first convolved with Gaussian-blurs at different scales. The convolved images are grouped by octave (an octave corresponds to doubling the value of σ {\displaystyle \sigma } ), and the value of k i {\displaystyle k_{i}} is selected so that we obtain a fixed number of convolved images per octave. Then the Difference-of-Gaussian images are taken from adjacent Gaussian-blurred images per octave.
Radiation damage Summary Radiation_damage Radiation damage is the effect of ionizing radiation on physical objects including non-living structural materials. It can be either detrimental or beneficial for materials. Radiobiology is the study of the action of ionizing radiation on living things, including the health effects of radiation in humans. High doses of ionizing radiation can cause damage to living tissue such as radiation burning and harmful mutations such as causing cells to become cancerous, and can lead to health problems such as radiation poisoning.
Coastal geography Physical processes Coastal_geography > Physical processes The main physical Weathering process on beaches is salt-crystal growth. Wind carries salt spray onto rocks, where it is absorbed into small pores and cracks within the rocks. There the water evaporates and the salt crystallises, creating pressure and often breaking down the rock. In some beaches calcium carbonate is able to bind together other sediments to form beachrock and in warmer areas dunerock. Wind erosion is also a form of erosion, dust and sand is carried around in the air and slowly erodes rock, this happens in a similar way in the sea were the salt and sand is washed up onto the rocks.
Organic reaction Classifications Organic_chemical_reaction > Classifications Participating atoms undergo changes in charge, both in the formal sense as well as in terms of the actual electron density. The vast majority of organic reactions fall under this category. Radical reactions are characterized by species with unpaired electrons (radicals) and the movement of single electrons.
Q-Pochhammer symbol q-series Q-Pochhammer_symbol > q-series A q-series is a series in which the coefficients are functions of q, typically expressions of ( a ; q ) n {\displaystyle (a;q)_{n}} . Early results are due to Euler, Gauss, and Cauchy. The systematic study begins with Eduard Heine (1843).
Viable System Model Applying VSM Algedonic_feedback > Applying VSM If things go wrong and levels of risk increase the System 3 asks for help or puts it to colleagues for a remedy. This is the pain of an algedonic alert, which can be automatic when performance fails to achieve capability targets. The autonomic 3–2–1 homeostatic loop's problem is absorbed for solution within the autonomy of its metasystem.
Polynomial system Coefficients in a number field or in a finite field with non-prime order Polynomial_system_of_equations > Extensions > Coefficients in a number field or in a finite field with non-prime order The elements of an algebraic number field are usually represented as polynomials in a generator of the field which satisfies some univariate polynomial equation. To work with a polynomial system whose coefficients belong to a number field, it suffices to consider this generator as a new variable and to add the equation of the generator to the equations of the system. Thus solving a polynomial system over a number field is reduced to solving another system over the rational numbers. For example, if a system contains 2 {\displaystyle {\sqrt {2}}} , a system over the rational numbers is obtained by adding the equation r22 – 2 = 0 and replacing 2 {\displaystyle {\sqrt {2}}} by r2 in the other equations. In the case of a finite field, the same transformation allows always supposing that the field k has a prime order.
Serine/arginine-rich splicing factor 1 Stability and fidelity Serine/arginine-rich_splicing_factor_1 > Biological importance > Stability and fidelity ASF/SF2 is involved in genomic stability; it is thought that RNA Polymerase recruits ASF/SF2 to nascent RNA transcripts to impede formation of mutagenic DNA:RNA hybrid R-loop structures between the transcript and the template DNA. In this way, ASF/SF2 is protecting cells from the potential deleterious effects of transcription itself. ASF/SF2 is also implicated in cellular mechanisms to hinder exon skipping and to ensure splicing is occurring accurately and correctly.
Chemotherapy Anemia Chemotherapy > Adverse effects > Anemia Extremely low platelet counts may be temporarily boosted through platelet transfusions and new drugs to increase platelet counts during chemotherapy are being developed. Sometimes, chemotherapy treatments are postponed to allow platelet counts to recover. Fatigue may be a consequence of the cancer or its treatment, and can last for months to years after treatment. One physiological cause of fatigue is anemia, which can be caused by chemotherapy, surgery, radiotherapy, primary and metastatic disease or nutritional depletion. Aerobic exercise has been found to be beneficial in reducing fatigue in people with solid tumours.
Globalization and disease Tuberculosis Globalization_and_disease > Specific diseases > Tuberculosis It is the most prevalent, life-threatening infection among AIDS patients. It has increased in areas where HIV seroprevalence is high.Air travel and the other methods of travel which have made global interaction easier, have increased the spread of TB across different societies. Luckily, the BCG vaccine was developed, which prevents TB meningitis and miliary TB in childhood.
Radiation storm Description Radiation_storm > Description SPEs occur when charged particles in the Sun's atmosphere are accelerated to extremely high velocities. These charged particles, referred to as solar energetic particles, can escape into interplanetary space where they follow the interplanetary magnetic field. When solar energetic particles interact with the Earth's magnetosphere, they are guided by the Earth's magnetic field towards the north and south poles where they can penetrate into the upper atmosphere.
Topoisomerase inhibitor Non-intercalating poisons Topoisomerase_inhibitor > Topoisomerase II inhibitors > Anticancer therapeutics > Non-intercalating poisons Additionally, studies have shown when treated with etoposide derivatives there is an anti-leukemic dose response that differ compared to the normal hematopoietic elements. Etoposide is a highly schedule-dependent drug and is typically administered orally and recommended to take twice the dosage for effective treatment. However, with the selective dosage, etoposide treatment is dose limiting proposing toxic effects like myelosupression (leukopenia) and primarily hematologic.
Relativistic quantum mechanics Relativistic quantum mechanics and field theory Relativistic_quantum_mechanics > Further reading > Relativistic quantum mechanics and field theory (2010). Elementary particle physics, Quantum Field Theory. Vol.
Mobius-Huckel concept The Möbius–Hückel circle mnemonic Möbius–Hückel_concept > The theory and concept > The Möbius–Hückel circle mnemonic To determine the energy levels, the polygon corresponding to the cyclic annulene is desired is inscribed in the circle of radius 2β and centered at α (the energy of an isolated p orbital). The y-coordinate of the vertices of the polygon are the simple Hückel theory orbital energies. For systems with Hückel topology, the vertex is positioned at the circle bottom as suggested by Frost; for systems with Möbius topology, a polygon side is positioned at the circle bottom. In other words, for an N carbon system, the Möbius Frost circle is rotated by π/N radians compared to the Hückel system.
Linear classification Discriminative training Linear_classifier > Generative models vs. discriminative models > Discriminative training Discriminative training of linear classifiers usually proceeds in a supervised way, by means of an optimization algorithm that is given a training set with desired outputs and a loss function that measures the discrepancy between the classifier's outputs and the desired outputs. Thus, the learning algorithm solves an optimization problem of the form arg ⁡ min w R ( w ) + C ∑ i = 1 N L ( y i , w T x i ) {\displaystyle {\underset {\mathbf {w} }{\arg \min }}\;R(\mathbf {w} )+C\sum _{i=1}^{N}L(y_{i},\mathbf {w} ^{\mathsf {T}}\mathbf {x} _{i})} where w is a vector of classifier parameters, L(yi, wTxi) is a loss function that measures the discrepancy between the classifier's prediction and the true output yi for the i'th training example, R(w) is a regularization function that prevents the parameters from getting too large (causing overfitting), and C is a scalar constant (set by the user of the learning algorithm) that controls the balance between the regularization and the loss function.Popular loss functions include the hinge loss (for linear SVMs) and the log loss (for linear logistic regression). If the regularization function R is convex, then the above is a convex problem. Many algorithms exist for solving such problems; popular ones for linear classification include (stochastic) gradient descent, L-BFGS, coordinate descent and Newton methods.
Chemical toilet Summary Chemical_toilet A chemical toilet collects human excreta in a holding tank and uses chemicals to minimize odors. They do not require a connection to a water supply and are used in a variety of situations. These toilets are usually, but not always, self-contained and movable. A chemical toilet is structured around a relatively small tank, which needs to be emptied frequently.
Archaea Metabolism Archaea > Metabolism One compound acts as an electron donor and one as an electron acceptor. The energy released is used to generate adenosine triphosphate (ATP) through chemiosmosis, the same basic process that happens in the mitochondrion of eukaryotic cells.Other groups of archaea use sunlight as a source of energy (they are phototrophs), but oxygen–generating photosynthesis does not occur in any of these organisms. Many basic metabolic pathways are shared among all forms of life; for example, archaea use a modified form of glycolysis (the Entner–Doudoroff pathway) and either a complete or partial citric acid cycle.
Abel–Ruffini theorem Algebraic solutions and field theory Abel–Ruffini_theorem > Proof > Algebraic solutions and field theory {\displaystyle K_{i}(x_{i}).} So, if one starts from a solution in terms of radicals, one gets an increasing sequence of fields such that the last one contains the solution, and each is a normal extension of the preceding one with a Galois group that is cyclic. Conversely, if one has such a sequence of fields, the equation is solvable in terms of radicals. For proving this, it suffices to prove that a normal extension with a cyclic Galois group can be built from a succession of radical extensions.
Glossary of engineering: A–L E Glossary_of_engineering:_A–L > E Electromechanics focuses on the interaction of electrical and mechanical systems as a whole and how the two systems interact with each other. This process is especially prominent in systems such as those of DC or AC rotating electrical machines which can be designed and operated to generate power from a mechanical process (generator) or used to power a mechanical effect (motor). Electrical engineering in this context also encompasses electronics engineering.
Antigenic mimicry Autoimmunity Molecular_mimicry > Autoimmunity Molecular mimicry is defined as similar structures shared by molecules from dissimilar genes or by their protein products. Either the linear amino acid sequence or the conformational fit of the immunodominant epitope may be shared between the pathogen and host. This is also known as "cross-reactivity" between self antigen of the host and immunodominant epitopes of the pathogen. An autoimmune response is then generated against the epitope. Due to similar sequence homology in the epitope between the pathogen and the host, cells and tissues of the host associated with the protein are destroyed as a result of the autoimmune response.
Ableism Summary Ableism Ableism is discrimination in favor of non-disabled people, while disablism is discrimination against disabled people.There are stereotypes which are either associated with disability in general, or they are associated with specific impairments or chronic health conditions (for instance the presumption that all disabled people want to be cured, the presumption that wheelchair users also have an intellectual disability, or the presumption that blind people have some special form of insight). These stereotypes, in turn, serve as a justification for discriminatory practices, and reinforce discriminatory attitudes and behaviors toward people who are disabled. Labeling affects people when it limits their options for action or changes their identity.In ableist societies, the lives of disabled people is considered less worth living, or disabled people less valuable, even sometimes expendable. The eugenics movement of the early 20th century is considered an expression of widespread ableism.Ableism can be further understood by reading literature which is written and published by those who experience disability and ableism first-hand. Disability studies is an academic discipline which is also beneficial when non-disabled people pursue it in order to gain a better understanding of ableism.
Mathematical symbol Calculus Table_of_mathematical_symbols > Calculus 2. With a subscript and a superscript, or expressions placed below and above it, denotes a definite integral. For example, ∫ a b x 2 d x = b 3 − a 3 3 {\displaystyle \textstyle \int _{a}^{b}x^{2}dx={\frac {b^{3}-a^{3}}{3}}} .
Warnier/Orr diagram Recursion Warnier/Orr_diagram > Constructs in Warnier/Orr diagrams > Recursion Recursion is the least used of the constructs. It is used to indicate that a set contains an earlier or a less ordered version of itself. In the classic "bill of materials" problem components contain parts and other sub-components.
Prion disease PrP and regulated cell death Prion_disease > Prion protein > Normal function of PrP > PrP and regulated cell death MAVS, RIP1, and RIP3 are prion-like proteins found in other parts of the body. They also polymerise into filamentous amyloid fibers which initiate regulated cell death in the case of a viral infection to prevent the spread of virions to other, surrounding cells.
Neutralization (chemistry) Meaning of "neutralization" Neutralization_reaction > Meaning of "neutralization" Ba(OH)2 + 2 H+ → Ba2+ + 2 H2OThe same equation relating the concentrations of acid and base applies. The concept of neutralization is not limited to reactions in solution. For example, the reaction of limestone with acid such as sulfuric acid is also a neutralization reaction. CO3(s) + H2SO4(aq) → (Ca2+, Mg2+)(aq) + SO2−4(aq) + CO2(g) + H2OSuch reactions are important in soil chemistry.
Kyle Cranmer Summary Kyle_Cranmer Cranmer also discussed the discovery of the Higgs boson in a TedxTalk in February, 2013.Cranmer obtained his Ph.D. in physics from the University of Wisconsin-Madison in 2005 under Sau Lan Wu and his B.A. in mathematics and physics from Rice University.
Hydrogen isotope biogeochemistry Chemistry of hydrogen exchange Hydrogen_isotope_biogeochemistry > Physical chemistry > Chemistry of hydrogen exchange One of the major complications in studying hydrogen isotopes is the issue of exchangeability. At many time scales, ranging from hours to geological epochs, scientists have to consider if the hydrogen moieties in studied molecules are the original species or if they represent exchange with water or mineral hydrogen near by. Research in this area is still inconclusive in regards to rates of exchange, but it is generally understood that hydrogen exchange complicates the preservation of information in isotope studies.
Probabilistic bisimulation Summary Probabilistic_bisimulation In theoretical computer science, probabilistic bisimulation is an extension of the concept of bisimulation for fully probabilistic transition systems first described by K.G. Larsen and A. Skou.A discrete probabilistic transition system is a triple S = ( St , Act , τ: St × Act × St → ) {\displaystyle S=(\operatorname {St} ,\operatorname {Act} ,\tau :\operatorname {St} \times \operatorname {Act} \times \operatorname {St} \rightarrow )} where τ ( s , a , t ) {\displaystyle \tau (s,a,t)} gives the probability of starting in the state s, performing the action a and ending up in the state t. The set of states is assumed to be countable. There is no attempt to assign probabilities to actions. It is assumed that the actions are chosen nondeterministically by an adversary or by the environment.
Ideal lattice Use in cryptography Ideal_lattice > Use in cryptography In 2014, Peikert presented a key transport scheme following the same basic idea of Ding's, where the new idea of sending additional signal for rounding in Ding's construction is also utilized. A digital signature using the same concepts was done several years earlier by Vadim Lyubashevsky in, "Lattice Signatures Without Trapdoors." Together, the work of Peikert and Lyubashevsky provide a suite of Ring-LWE based quantum attack resistant algorithms with the same security reductions.
Social simulation game Examples Social_simulation_game > Examples Shenmue series (1999–2019) The Sims series (2000–2014) The Sims (2000)—by Will Wright, published by EA for the PC. The Sims 2 (2004). The Sims 3 (2009).
Triangle (geometry) Basic facts Triangle_(geometry) > Basic facts Triangles are assumed to be two-dimensional plane figures, unless the context provides otherwise (see § Non-planar triangles, below). In rigorous treatments, a triangle is therefore called a 2-simplex (see also Polytope). Elementary facts about triangles were presented by Euclid, in books 1–4 of his Elements, written around 300 BC. The sum of the measures of the interior angles of a triangle in Euclidean space is always 180 degrees.
Errors-in-variables models Terminology and assumptions Errors-in-variables_regression > Specification > Terminology and assumptions This is the most common assumption, it implies that the errors are introduced by the measuring device and their magnitude does not depend on the value being measured. Mean-independence: E ⁡ = 0 , {\displaystyle \operatorname {E} \,=\,0,} the errors are mean-zero for every value of the latent regressor. This is a less restrictive assumption than the classical one, as it allows for the presence of heteroscedasticity or other effects in the measurement errors.
Mathematical product Summary Mathematical_product In mathematics, a product is the result of multiplication, or an expression that identifies objects (numbers or variables) to be multiplied, called factors. For example, 21 is the product of 3 and 7 (the result of multiplication), and x ⋅ ( 2 + x ) {\displaystyle x\cdot (2+x)} is the product of x {\displaystyle x} and ( 2 + x ) {\displaystyle (2+x)} (indicating that the two factors should be multiplied together). When one factor is an integer, the product is called a multiple. The order in which real or complex numbers are multiplied has no bearing on the product; this is known as the commutative law of multiplication.
Acute respiratory distress syndrome Pathophysiology Acute_respiratory_distress_syndrome > Pathophysiology ARDS is a form of fluid accumulation in the lungs not explained by heart failure (noncardiogenic pulmonary edema). It is typically provoked by an acute injury to the lungs that results in flooding of the lungs' microscopic air sacs responsible for the exchange of gases such as oxygen and carbon dioxide with capillaries in the lungs. Additional common findings in ARDS include partial collapse of the lungs (atelectasis) and low levels of oxygen in the blood (hypoxemia). The clinical syndrome is associated with pathological findings including pneumonia, eosinophilic pneumonia, cryptogenic organizing pneumonia, acute fibrinous organizing pneumonia, and diffuse alveolar damage (DAD).
Hexagram Other symbolic uses Hexagram > Other uses > Other symbolic uses In German this is called "Bierstern" (beer star) or "Brauerstern" (brewer's star). A six-point star is used as an identifying mark of the Folk Nation alliance of US street gangs.
Passive seismic Summary Passive_seismic Local time must be taken into consideration, picking intervals with less human induced noise. Even relatively distant earthquakes are visible in the recorded spectrograms and must also be excluded from analysis.The similar method have been also applied in another planets. For instance, during Apollo missions, the Passive Seismic Experiment sensors were deployed that detected lunar "moonquakes" and provided information about the internal structure of the Moon.Passive seismic is much less expensive than well drilling.
Chronic viral hepatitis Viral hepatitis Chronic_viral_hepatitis > Mechanism > Viral hepatitis The pathway by which hepatic viruses cause viral hepatitis is best understood in the case of hepatitis B and C. The viruses do not directly activate apoptosis (cell death). Rather, infection of liver cells activates the innate and adaptive arms of the immune system leading to an inflammatory response which causes cellular damage and death, including viral-induced apoptosis via the induction of the death receptor-mediated signaling pathway. Depending on the strength of the immune response, the types of immune cells involved and the ability of the virus to evade the body's defense, infection can either lead to clearance (acute disease) or persistence (chronic disease) of the virus. The chronic presence of the virus within liver cells results in multiple waves of inflammation, injury and wound healing that over time lead to scarring or fibrosis and culminate in hepatocellular carcinoma.
Domain theory Directed sets as converging specifications Domain_theory > A guide to the formal definitions > Directed sets as converging specifications Indeed, in the theory of metric spaces, sequences play a role that is in many aspects analogous to the role of directed sets in domain theory. Now, as in the case of sequences, we are interested in the limit of a directed set. According to what was said above, this would be an element that is the most general piece of information that extends the information of all elements of the directed set, i.e. the unique element that contains exactly the information that was present in the directed set, and nothing more.
First law of thermodynamics Adiabatic processes First_law_of_thermodynamics > Evidence for the first law of thermodynamics for closed systems > Adiabatic processes It is irrelevant if the work is electrical, mechanical, chemical,... or if done suddenly or slowly, as long as it is performed in an adiabatic way, that is to say, without heat transfer into or out of the system. Evidence of this kind shows that to increase the temperature of the water in the tank, the qualitative kind of adiabatically performed work does not matter. No qualitative kind of adiabatic work has ever been observed to decrease the temperature of the water in the tank.
Anne R. Douglass Summary Anne_R._Douglass Anne Ritger Douglass is atmospheric physicist known for her research on chlorinated compounds and the ozone layer.
Cancer Stem Cells Treatment Cancer_stem_cell > Implications > Treatment 4. They upregulate DNA damage repair proteins. 5. They are characterized by an overactivation of anti-apoptotic signaling pathways.After chemotherapy treatment, surviving CSCs are able to repopulate the tumor and cause a relapse. Additional treatment targeted at removing CSCs in addition to cancerous somatic cells must be used to prevent this.
Carbon-carbon bonds Summary C-C_bond In fact, the carbon atoms in the single bond need not be of the same hybridization. Carbon atoms can also form double bonds in compounds called alkenes or triple bonds in compounds called alkynes.
Racial diversity Genetically differentiated populations Racial_classification > Modern scholarship > Biological classification > Genetically differentiated populations Another way to look at differences between populations is to measure genetic differences rather than physical differences between groups. The mid-20th-century anthropologist William C. Boyd defined race as: "A population which differs significantly from other populations in regard to the frequency of one or more of the genes it possesses. It is an arbitrary matter which, and how many, gene loci we choose to consider as a significant 'constellation'". Leonard Lieberman and Rodney Kirk have pointed out that "the paramount weakness of this statement is that if one gene can distinguish races then the number of races is as numerous as the number of human couples reproducing."
Content delivery network interconnection Exemplary operation of CDNI interfaces in content delivery Content_delivery_network_interconnection > Exemplary operation of CDNI interfaces in content delivery The sequence diagram presented in the figure below provides some details on CDNI and the iterative DNS redirection operation. In the depicted example, a UE downloads content from the address cdn.csp.com/foo, which is primarily delivered by the CDN-A on behalf of a CSP with the address csp.com. Before any request redirection, the CDN-B (dCDN) announces information on supported footprint and capabilities. The UE performs a DNS lookup for a server cdn.csp.com in the domain of the CSP from which it is going to download the content.
Hamilton's equation Riemannian manifolds Hamiltonian_(function) > From symplectic geometry to Hamilton's equations > Riemannian manifolds An important special case consists of those Hamiltonians that are quadratic forms, that is, Hamiltonians that can be written as where ⟨ , ⟩q is a smoothly varying inner product on the fibers T∗qQ, the cotangent space to the point q in the configuration space, sometimes called a cometric. This Hamiltonian consists entirely of the kinetic term. If one considers a Riemannian manifold or a pseudo-Riemannian manifold, the Riemannian metric induces a linear isomorphism between the tangent and cotangent bundles. (See Musical isomorphism).
Monohydrogen phosphate Acid-base equilibria Monohydrogen_phosphate > Acid-base equilibria Hydrogenphosphate is an intermediate in the multistep conversion of phosphoric acid to phosphate:
Gauge group (mathematics) Summary Gauge_group It is a Lie group. A key point is that the action of G ¯ k ( X ) {\displaystyle {\overline {G}}_{k}(X)} on a Sobolev completion A k {\displaystyle A_{k}} of a space of principal connections is smooth, and that an orbit space A k / G ¯ k ( X ) {\displaystyle A_{k}/{\overline {G}}_{k}(X)} is a Hilbert space. It is a configuration space of quantum gauge theory.
Theoretical chemist Branches of theoretical chemistry Theoretical_chemist > Branches of theoretical chemistry Molecular dynamics Application of classical mechanics for simulating the movement of the nuclei of an assembly of atoms and molecules. The rearrangement of molecules within an ensemble is controlled by Van der Waals forces and promoted by temperature. Molecular mechanics Modeling of the intra- and inter-molecular interaction potential energy surfaces via potentials.
Plant efficiency Heat rate Plant_efficiency > Heat rate A heat rate value of 4 MJ/MJ gives an efficiency factor of 25%. For other units, make sure to use a corresponding conversion factor for the units. For example if using Btu/kWh, use a conversion factor of 3,412 Btu per kWh to calculate the efficiency factor.
Primary stress Summary Tertiary_stress Some languages have fixed stress, meaning that the stress on virtually any multisyllable word falls on a particular syllable, such as the penultimate (e.g. Polish) or the first (e.g. Finnish). Other languages, like English and Russian, have lexical stress, where the position of stress in a word is not predictable in that way but lexically encoded. Sometimes more than one level of stress, such as primary stress and secondary stress, may be identified.
Normalization Process Theory Content Normalization_Process_Theory > Content It reveals "the work that actors do as they engage with some ensemble of activities (that may include new or changed ways of thinking, acting, and organizing) and by which means it becomes routinely embedded in the matrices of already existing, socially patterned, knowledge and practices". These have explored objects, agents, and contexts. In a paper published under a creative commons license, May and colleagues describe how, since 2006, NPT has undergone three iterations.
STO-nG basis sets Accuracy STO-nG_basis_sets > Accuracy The exact energy of the 1s electron of H atom is −0.5 hartree, given by a single Slater-type orbital with exponent 1.0. The following table illustrates the increase in accuracy as the number of primitive Gaussian functions increases from 3 to 6 in the basis set.
Interval exchange transformation Properties Interval_exchange_map > Properties Any interval exchange transformation T π , λ {\displaystyle T_{\pi ,\lambda }} is a bijection of {\displaystyle } to itself that preserves the Lebesgue measure. It is continuous except at a finite number of points. The inverse of the interval exchange transformation T π , λ {\displaystyle T_{\pi ,\lambda }} is again an interval exchange transformation.
Final drive ratio Belt drives Gear_ratios > Belt drives Belts can have teeth in them also and be coupled to gear-like pulleys. Special gears called sprockets can be coupled together with chains, as on bicycles and some motorcycles. Again, exact accounting of teeth and revolutions can be applied with these machines. For example, a belt with teeth, called the timing belt, is used in some internal combustion engines to synchronize the movement of the camshaft with that of the crankshaft, so that the valves open and close at the top of each cylinder at exactly the right time relative to the movement of each piston. A chain, called a timing chain, is used on some automobiles for this purpose, while in others, the camshaft and crankshaft are coupled directly together through meshed gears. Regardless of which form of drive is employed, the crankshaft-to-camshaft gear ratio is always 2:1 on four-stroke engines, which means that for every two revolutions of the crankshaft the camshaft will rotate once.
Finite subcover Examples Compact_subspace > Examples Consider the set K of all functions f: R {\displaystyle \mathbb {R} } → from the real number line to the closed unit interval, and define a topology on K so that a sequence { f n } {\displaystyle \{f_{n}\}} in K converges towards f ∈ K if and only if { f n ( x ) } {\displaystyle \{f_{n}(x)\}} converges towards f(x) for all real numbers x. There is only one such topology; it is called the topology of pointwise convergence or the product topology. Then K is a compact topological space; this follows from the Tychonoff theorem. Consider the set K of all functions f: → satisfying the Lipschitz condition \|f(x) − f(y)\| ≤ \|x − y\| for all x, y ∈ .
Compound probability distribution Overdispersion modeling Compound_distribution > Applications > Overdispersion modeling Compound distributions are useful for modeling outcomes exhibiting overdispersion, i.e., a greater amount of variability than would be expected under a certain model. For example, count data are commonly modeled using the Poisson distribution, whose variance is equal to its mean. The distribution may be generalized by allowing for variability in its rate parameter, implemented via a gamma distribution, which results in a marginal negative binomial distribution. This distribution is similar in its shape to the Poisson distribution, but it allows for larger variances. Similarly, a binomial distribution may be generalized to allow for additional variability by compounding it with a beta distribution for its success probability parameter, which results in a beta-binomial distribution.
Domain theory Special types of domains Domain_theory > A guide to the formal definitions > Special types of domains A simple special case of a domain is known as an elementary or flat domain. This consists of a set of incomparable elements, such as the integers, along with a single "bottom" element considered smaller than all other elements. One can obtain a number of other interesting special classes of ordered structures that could be suitable as "domains". We already mentioned continuous posets and algebraic posets.
Drug form Summary Unit-dose_packaging The term dosage form can also sometimes refer only to the pharmaceutical formulation of a drug product's constituent drug substance(s) and any blends involved, without considering matters beyond that (like how it is ultimately configured as a consumable product such as a capsule, patch, etc.). Because of the somewhat vague boundaries and unclear overlap of these terms and certain variants and qualifiers within the pharmaceutical industry, caution is often advisable when conversing with someone who may be unfamiliar with another person's use of the term. Depending on the method/route of administration, dosage forms come in several types.
Streptococcus pneumoniae Summary Streptococcus_pneumoniae These invasive pneumococcal diseases include bronchitis, rhinitis, acute sinusitis, otitis media, conjunctivitis, meningitis, sepsis, osteomyelitis, septic arthritis, endocarditis, peritonitis, pericarditis, cellulitis, and brain abscess.Streptococcus pneumoniae can be differentiated from the viridans streptococci, some of which are also alpha-hemolytic, using an optochin test, as S. pneumoniae is optochin-sensitive. S. pneumoniae can also be distinguished based on its sensitivity to lysis by bile, the so-called "bile solubility test". The encapsulated, Gram-positive, coccoid bacteria have a distinctive morphology on Gram stain, lancet-shaped diplococci. They have a polysaccharide capsule that acts as a virulence factor for the organism; more than 100 different serotypes are known, and these types differ in virulence, prevalence, and extent of drug resistance.
Autonomous bus Technology used in vehicular automation Automated_Driving > Technology used in vehicular automation These systems are known as advanced driver-assistance systems, and contain systems to do such actions as parallel parking and emergency braking. Along these systems, autonomous navigation systems play a role in the development of autonomous vehicles. In implementing the navigation system, there are two ways in which navigation can be implemented: sensing from one vehicle to another or sensing from the infrastructure.
Cardiac function Factors influencing heart rate Cardiac_function > Heart rate > Factors influencing heart rate In addition to the autonomic nervous system, other factors can affect this. These include epinephrine, norepinephrine, and thyroid hormones; levels of various ions including calcium, potassium, and sodium; body temperature; hypoxia; and pH balance . Factors that increase heart rate also trigger an increase in stroke volume. As with skeletal muscles the heart can increase in size and efficiency with exercise.
Electronics circuit simulator Summary Electronics_circuit_simulator The most well known analog simulator is SPICE. Probably the best known digital simulators are those based on Verilog and VHDL. Some electronics simulators integrate a schematic editor, a simulation engine, and on-screen waveform display (see Figure 1), allowing designers to rapidly modify a simulated circuit and see what effect the changes have on the output.
Laser surface velocimeter The differential Doppler process Laser_surface_velocimeter > Principle of operation > The differential Doppler process The Doppler effect (or Doppler shift) is the change in frequency of a wave for an observer moving relative to the source of the wave. The wave has a frequency f and propagates at a speed c When the observer moves at a velocity of v relative to the source, they receive a different frequency f' according to f ′ = f ( c − v c ) = f ( 1 − v c ) {\displaystyle f'=f({\frac {c-v}{c}})=f\left(1-{\frac {v}{c}}\right)} The above analysis is an approximation for small velocities in comparison to the speed of light which is fulfilled very well for practically all technically relevant velocities. To make a measurement on moving objects, which can in principle be of any length, requires a measurement design with an observation axis for the sensor which is at a right angle to the direction of movement of the object under investigation.
Divergent series Sum of a series Summability_methods > Classical summation methods > Sum of a series Cauchy's classical definition of the sum of a series a0 + a1 + ... defines the sum to be the limit of the sequence of partial sums a0 + ... + an. This is the default definition of convergence of a sequence.
Door-in-the-face technique Combining DITF and FITD Door-in-the-face_technique > DITF vs. FITD > Combining DITF and FITD Study 3: This study used the same requests from the study 2. Confederates made the second request immediately to participants who rejected the first but waited two to three days for those who complied with the first request.
Number words 16: hexadecimal Collective_numeral > Basis of counting system > 16: hexadecimal Hexadecimal systems are based on the number 16. The traditional Chinese units of measurement were base-16. For example, one jīn (斤) in the old system equals sixteen taels.
Geometrically finite group Summary Geometric_finiteness In geometry, a group of isometries of hyperbolic space is called geometrically finite if it has a well-behaved fundamental domain. A hyperbolic manifold is called geometrically finite if it can be described in terms of geometrically finite groups.
Garbage can model Summary Garbage_can_model The mix of garbage (streams) in a single can (choice opportunity) depends on the mix of cans available, on the labels attached to each can, and on what garbage is currently being generated. The mix of garbage in a single can also depend on the speed at which the garbage is collected and removed from the scene, for example, how long before problems, solutions, and/or participants move on to other choice opportunities, or, depending on how long the current choice opportunity remains available. This anarchic view of decision making contrasts with traditional decision theory.
Simultaneous linear equations Geometric interpretation Vector_equation > Solution set > Geometric interpretation For a system involving two variables (x and y), each linear equation determines a line on the xy-plane. Because a solution to a linear system must satisfy all of the equations, the solution set is the intersection of these lines, and is hence either a line, a single point, or the empty set. For three variables, each linear equation determines a plane in three-dimensional space, and the solution set is the intersection of these planes. Thus the solution set may be a plane, a line, a single point, or the empty set. For example, as three parallel planes do not have a common point, the solution set of their equations is empty; the solution set of the equations of three planes intersecting at a point is single point; if three planes pass through two points, their equations have at least two common solutions; in fact the solution set is infinite and consists in all the line passing through these points.For n variables, each linear equation determines a hyperplane in n-dimensional space. The solution set is the intersection of these hyperplanes, and is a flat, which may have any dimension lower than n.
List of screw drives Torx Phillips_head > Hexalobular (Torx) > Torx The hexalobular socket screw drive, often referred to by the original proprietary brand name Torx ( ) or by the alternative generic name star drive, uses a star-shaped recess in the fastener with six rounded points. It was designed to permit increased torque transfer from the driver to the bit compared to other drive systems. The drive was developed in 1967 by Camcar Textron.
Floppy-disk controller Summary Floppy_Disk_Controller A floppy-disk controller (FDC) has evolved from a discrete set of components on one or more circuit boards to a special-purpose integrated circuit (IC or "chip") or a component thereof. An FDC directs and controls reading from and writing to a computer's floppy disk drive (FDD). The FDC is responsible for reading data presented from the host computer and converting it to the drive's on-disk format using one of a number of encoding schemes, like FM encoding (single density) or MFM encoding (double density), and reading those formats and returning it to its original binary values. Depending on the platform, data transfers between the controller and host computer would be controlled by the computer's own microprocessor, or an inexpensive dedicated microprocessor like the MOS 6507 or Zilog Z80.
Pythagorean Theorem Solid geometry The_Pythagorean_theorem > Generalizations > Solid geometry The "hypotenuse" is the base of the tetrahedron at the back of the figure, and the "legs" are the three sides emanating from the vertex in the foreground. As the depth of the base from the vertex increases, the area of the "legs" increases, while that of the base is fixed. The theorem suggests that when this depth is at the value creating a right vertex, the generalization of Pythagoras' theorem applies. In a different wording: Given an n-rectangular n-dimensional simplex, the square of the (n − 1)-content of the facet opposing the right vertex will equal the sum of the squares of the (n − 1)-contents of the remaining facets.
1s orbital Modern conceptions and connections to the Heisenberg uncertainty principle D_orbital > History > Modern conceptions and connections to the Heisenberg uncertainty principle Immediately after Heisenberg discovered his uncertainty principle, Bohr noted that the existence of any sort of wave packet implies uncertainty in the wave frequency and wavelength, since a spread of frequencies is needed to create the packet itself. In quantum mechanics, where all particle momenta are associated with waves, it is the formation of such a wave packet which localizes the wave, and thus the particle, in space. In states where a quantum mechanical particle is bound, it must be localized as a wave packet, and the existence of the packet and its minimum size implies a spread and minimal value in particle wavelength, and thus also momentum and energy. In quantum mechanics, as a particle is localized to a smaller region in space, the associated compressed wave packet requires a larger and larger range of momenta, and thus larger kinetic energy.
History of optics Quantum optics History_of_optics > Quantum optics Laser science—research into principles, design and application of these devices—became an important field, and the quantum mechanics underlying the laser's principles was studied now with more emphasis on the properties of light, and the name quantum optics became customary. As laser science needed good theoretical foundations, and also because research into these soon proved very fruitful, interest in quantum optics rose. Following the work of Dirac in quantum field theory, George Sudarshan, Roy J. Glauber, and Leonard Mandel applied quantum theory to the electromagnetic field in the 1950s and 1960s to gain a more detailed understanding of photodetection and the statistics of light (see degree of coherence).
Transformer proteins Summary Transformer_proteins A transformer protein (TFP) also known as a metamorphic protein is a protein that can interconvert between two or more shapes (also known as folds) each having a different function.The fold of a protein is defined by how the two-dimensional linear protein polypeptide folds up into a three-dimensional structure. Most proteins adopt a single stable fold. But some proteins have marginal structural stability and can rapidly interconvert between two or more folds. Protein structures in a given environment were thought to be defined completely by their amino acid sequence.
Complex integration Direct methods Contour_integral > Direct methods Direct methods involve the calculation of the integral by means of methods similar to those in calculating line integrals in multivariate calculus. This means that we use the following method: parametrizing the contour The contour is parametrized by a differentiable complex-valued function of real variables, or the contour is broken up into pieces and parametrized separately. substitution of the parametrization into the integrand Substituting the parametrization into the integrand transforms the integral into an integral of one real variable. direct evaluation The integral is evaluated in a method akin to a real-variable integral.
Anonymous P2P Anonymity and pseudonymity Anonymous_P2P > Functioning of anonymous P2P > Anonymity and pseudonymity This overlay address functions as a pseudonym for the node, allowing messages to be addressed to it. In Freenet, on the other hand, messages are routed using keys that identify specific pieces of data rather than specific nodes; the nodes themselves are anonymous. The term anonymous is used to describe both kinds of network because it is difficult—if not impossible—to determine whether a node that sends a message originated the message or is simply forwarding it on behalf of another node.
Naked eye astronomy Environmental pollution Naked_eye_astronomy > Environmental pollution This is of importance in meteorology and for the "seeing" of astronomy. Light pollution is a significant problem for amateur astronomers but becomes less late at night when many lights are shut off. Air dust can be seen even far away from a city by its "light dome".
Passive safety Crashworthiness Passive_safety > Active and passive safety > Crashworthiness Cargo barriers are sometimes fitted to provide a physical barrier between passenger and cargo compartments in vehicles such as SUVs, station wagons and vans. These help prevent injuries caused by occupants being struck by unsecured cargo. They can also help prevent collapse of the roof in the event of a vehicle rollover.
Catalytic site In drug discovery Binding_pocket > In drug discovery Active sites can be mapped to aid the design of new drugs such as enzyme inhibitors. This involves the description of the size of an active site and the number and properties of sub-sites, such as details of the binding interaction. Modern database technology called CPASS (Comparison of Protein Active Site Structures) however allows the comparison of active sites in more detail and the finding of structural similarity using software.
Steinhaus conjecture History and proof Steinhaus_conjecture > History and proof The only ways for this to happen are for one of the endpoints of A to be the last point in the sequence of multiples of θ (so that the corresponding endpoint of A + θ is missing) or for one of the given points to land within A + θ, preventing it from being a gap. A point can only land within A + θ if it is the first point in the sequence of multiples of θ, because otherwise its predecessor in the sequence would land within A, contradicting the assumption that A is a gap. So there can be at most three rigid gaps, the two on either side of the last point and the one in which the predecessor of the first point (if it were part of the sequence) would land. Because there are at most three rigid gaps, there are at most three lengths of gaps.
Spin lattice Wilson renormalization Ising_model > Four dimensions and above > 4 − ε dimensions – renormalization group > Wilson renormalization This equation is an identity inside any correlation function away from other insertions. After integrating out the modes with Λ < k < (1+b)Λ, it will be a slightly different identity. Since the form of the equation will be preserved, to find the change in coefficients it is sufficient to analyze the change in the H3 term.
Passive margin Active vs. passive margins Passive_margin > Key components > Active vs. passive margins The distinction between active and passive margins refers to whether a crustal boundary between oceanic lithosphere and continental lithosphere is a plate boundary. Active margins are found on the edge of a continent where subduction occurs. These are often marked by uplift and volcanic mountain belts on the continental plate. Less often there is a strike-slip fault, as defines the southern coastline of West Africa.
Dendroid (topology) Summary Dendroid_(topology) In mathematics, a dendroid is a type of topological space, satisfying the properties that it is hereditarily unicoherent (meaning that every subcontinuum of X is unicoherent), arcwise connected, and forms a continuum. The term dendroid was introduced by Bronisław Knaster lecturing at the University of Wrocław, although these spaces were studied earlier by Karol Borsuk and others.Borsuk (1954) proved that dendroids have the fixed-point property: Every continuous function from a dendroid to itself has a fixed point. Cook (1970) proved that every dendroid is tree-like, meaning that it has arbitrarily fine open covers whose nerve is a tree. The more general question of whether every tree-like continuum has the fixed-point property, posed by Bing (1951), was solved in the negative by David P. Bellamy, who gave an example of a tree-like continuum without the fixed-point property.
Price action trading Pull-back Price_action_trading > Pull-back Price action traders expect the market to adhere to the two attempts rule and will be waiting for the market to try to make a second swing in the pull-back, with the hope that it fails and therefore turns around to try the opposite - i.e. the trend resumes. One price action technique for following a pull-back with the aim of entering with-trend at the end of the pull-back is to count the new higher highs in the pull-back of a bull trend, or the new lower lows in the pull-back of a bear, i.e. in a bull trend, the pull-back will be composed of bars where the highs are successively lower and lower until the pattern is broken by a bar that puts in a high higher than the previous bar's high, termed an H1 (High 1). L1s (Low 1) are the mirror image in bear trend pull-backs.
Prion diseases Normal function of PrP Prion_disease > Prion protein > Normal function of PrP The physiological function of the prion protein remains poorly understood. While data from in vitro experiments suggest many dissimilar roles, studies on PrP knockout mice have provided only limited information because these animals exhibit only minor abnormalities. In research done in mice, it was found that the cleavage of PrP in peripheral nerves causes the activation of myelin repair in Schwann cells and that the lack of PrP proteins caused demyelination in those cells.
Peptide vaccine History Peptide_vaccine > History The traditional vaccines are the whole live or fixed pathogens. The second generation of vaccines is mainly the protein purified from the pathogen. The third generation of vaccines is the DNA or plasmid that can express the proteins of the pathogen. Peptide vaccines are the latest step in the evolution of vaccines.
Hand signaling (open outcry) Summary Hand_signaling_(open_outcry) Signals that occur with palms facing out and hands away from the body are an indication the gesturer wishes to sell. When traders face their palms in and hold their hands up, they are gesturing to buy. Numbers one through five are gestured on one hand with the fingers pointing directly upwards.
Child Development Index Summary Child_Development_Index Education: the percentage of primary school-age children who are not enrolled in school. For our measure of education deprivation, we use the opposite of the Net Primary Enrolment rate—i.e., 100—the NER. This gives us the percentage of primary school-age children who are not enrolled.What does the Child Development Index tell us about how children are faring around the world?
Data warehousing Benefits Data_Warehouses > Benefits Improve data quality, by providing consistent codes and descriptions, flagging or even fixing bad data. Present the organization's information consistently. Provide a single common data model for all data of interest regardless of the data's source.
Jordan–Wigner transformation Analogy between spins and fermions Jordan–Wigner_transformation > Analogy between spins and fermions The phase is determined by the number of occupied fermionic modes in modes k = 1 , … , j − 1 {\displaystyle k=1,\ldots ,j-1} of the field. The phase is equal to + 1 {\displaystyle +1} if the number of occupied modes is even, and − 1 {\displaystyle -1} if the number of occupied modes is odd. This phase is often expressed as e ( ± i π ∑ k = 1 j − 1 f k † f k ) = ∏ k = 1 j − 1 e ± i π f k † f k = ∏ k = 1 j − 1 e ± i π σ k z + I 2 = ∏ k = 1 j − 1 ( − σ k z ) .
Product rule Summary Product_rule In calculus, the product rule (or Leibniz rule or Leibniz product rule) is a formula used to find the derivatives of products of two or more functions. For two functions, it may be stated in Lagrange's notation as or in Leibniz's notation as The rule may be extended or generalized to products of three or more functions, to a rule for higher-order derivatives of a product, and to other contexts.
Quantum mechanical properties Philosophical implications Quantum_systems > Philosophical implications Since its inception, the many counter-intuitive aspects and results of quantum mechanics have provoked strong philosophical debates and many interpretations. The arguments centre on the probabilistic nature of quantum mechanics, the difficulties with wavefunction collapse and the related measurement problem, and quantum nonlocality. Perhaps the only consensus that exists about these issues is that there is no consensus.
Computational aesthetics Computational approaches Aesthetic_judgment > Derivative forms of aesthetics > Computational approaches Computational approaches to aesthetics emerged amid efforts to use computer science methods "to predict, convey, and evoke emotional response to a piece of art. It this field, aesthetics is not considered to be dependent on taste but is a matter of cognition, and, consequently, learning. In 1928, the mathematician George David Birkhoff created an aesthetic measure M = O/C as the ratio of order to complexity.Since about 2005, computer scientists have attempted to develop automated methods to infer aesthetic quality of images. Typically, these approaches follow a machine learning approach, where large numbers of manually rated photographs are used to "teach" a computer about what visual properties are of relevance to aesthetic quality.
Thermoelectric power source Uses Thermoelectric_generator > Uses Researchers have considered whether some of that energy could be recycled. (However, see below for problems that can arise.) Thermoelectric generators have also been investigated as standalone solar-thermal cells.
Dilatant Sterically stabilized suspensions Dilatant > Definitions > Stabilized suspensions > Sterically stabilized suspensions Different from electrostatics, sterically stabilized suspensions rely on the physical interaction of polymer chains attached to the surface of the particles to keep the suspension stabilized; the adsorbed polymer chains act as a spacer to keep the suspended particles separated at a sufficient distance to prevent the Hamaker attraction from dominating and pulling the particles out of suspension. The polymers are typically either grafted or adsorbed onto the surface of the particle. With grafted polymers, the backbone of the polymer chain is covalently bonded to the particle surface. Whereas an adsorbed polymer is a copolymer composed of lyophobic and lyophilic region, where the lyophobic region non-covalently adheres to the particle surface and the lyophilic region forms the steric boundary or spacer.
I cell Summary I_cell They are found in the cytoplasm of a cell in both prokaryotes and eukaryotes. They are seen in Mucolipidosis II, and Mucolipidosis III, also called inclusion-cell or I-cell disease where lysosomal enzyme transport and storage is affected. == References ==
Tarski's exponential function problem Conditional and equivalent results Tarski's_exponential_function_problem > Conditional and equivalent results Even the real version of Schanuel's conjecture is not a necessary condition for the decidability of the theory. In their paper, Macintyre and Wilkie showed that an equivalent result to the decidability of Th(Rexp) is what they dubbed the Weak Schanuel's Conjecture. This conjecture states that there is an effective procedure that, given n ≥ 1 and exponential polynomials in n variables with integer coefficients f1,..., fn, g, produces an integer η ≥ 1 that depends on n, f1,..., fn, g, and such that if α ∈ Rn is a non-singular solution of the system f 1 ( x 1 , … , x n , e x 1 , … , e x n ) = … = f n ( x 1 , … , x n , e x 1 , … , e x n ) = 0 {\displaystyle f_{1}(x_{1},\ldots ,x_{n},e^{x_{1}},\ldots ,e^{x_{n}})=\ldots =f_{n}(x_{1},\ldots ,x_{n},e^{x_{1}},\ldots ,e^{x_{n}})=0} then either g(α) = 0 or \|g(α)\| > η−1.

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