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Yo-yo (algorithm) Cost Yo-yo_(algorithm) > Cost The pre-processing phase is composed of an exchange through each edge of the two nodes incident on the edge. Thus we have a cost of ∑ v ∈ V d e g ( v ) = 2 m {\displaystyle \sum _{v\in V}deg(v)=2m} . The Yo-Yo phases consist of a forward and backward scan of the structure, hence 2 m i {\displaystyle 2m_{i}} messages, where m i {\displaystyle m_{i}} is the number of current active edges. The number of iterations is given by the number of iterations useful in order to delete each initial source.
Undergraduate Texts in Mathematics List of books Undergraduate_Texts_in_Mathematics > List of books Differential Equations: An Introduction with Mathematica (2nd ed.). doi:10.1007/978-1-4757-3949-7. ISBN 978-0-387-21284-5.
Chemical equilibrium Multiple equilibria Chemical_equilibrium > Multiple equilibria Consider the case of a dibasic acid H2A. When dissolved in water, the mixture will contain H2A, HA− and A2−. This equilibrium can be split into two steps in each of which one proton is liberated. H 2 A ↽ − − ⇀ HA − + H +: K 1 = HA − ↽ − − ⇀ A 2 − + H +: K 2 = {\displaystyle {\begin{array}{rl}{\ce {H2A <=> HA^- + H+}}:&K_{1}={\frac {{\ce {}}}{{\ce {}}}}\\{\ce {HA- <=> A^2- + H+}}:&K_{2}={\frac {{\ce {}}}{{\ce {}}}}\end{array}}} K1 and K2 are examples of stepwise equilibrium constants.
Parviz Moin Research Parviz_Moin > Research Moin pioneered the use of direct numerical simulation and large eddy simulation techniques for the study of turbulence physics, control and modelling concepts and has written widely on the structure of turbulent shear flows. His current interests include: interaction of turbulent flows and shock waves, aerodynamic noise and hydroacoustics, turbulence control, large eddy simulation and parallel computing. Moin is the founding director of the Center for Turbulence Research at Stanford and Ames. Established in 1987 as a research consortium between NASA and Stanford, the Center for Turbulence Research is devoted to fundamental studies of turbulent flows. He has been an Editor of the Annual Review of Fluid Mechanics since 2002.
Extensible Computational Chemistry Environment Summary Extensible_Computational_Chemistry_Environment The Extensible Computational Chemistry Environment (ECCE, pronounced "etch-ā") provides a sophisticated graphical user interface, scientific visualization tools, and the underlying data management framework enabling scientists to efficiently set up calculations and store, retrieve, and analyze the rapidly growing volumes of data produced by computational chemistry studies.
Query plan Query tuning Query_plan > Query tuning Some databases - like Oracle - provide a plan table for query tuning. This plan table will return the cost and time for executing a query. Oracle offers two optimization approaches: CBO or Cost Based Optimization RBO or Rule Based OptimizationRBO is slowly being deprecated.
Interrupts in 65xx processors Using BRK and COP Interrupts_in_65xx_processors > Using BRK and COP If BRK is used as a debugging device, the program counter may have to be adjusted to point to the signature in order for execution to resume where expected. Alternatively, a NOP may be inserted as a signature "placeholder," in which case no program counter adjustment will be required. The fact that BRK and COP double-increment the program counter before pushing it to the stack facilitates the technique of treating them as supervisor call instructions, as found on some mainframe computers.
Ensemble Kalman filter Observation matrix-free implementation Ensemble_Kalman_filter > Implementation > Observation matrix-free implementation Since we have replaced the covariance matrix with ensemble covariance, this leads to a simpler formula where ensemble observations are directly used without explicitly specifying the matrix H {\displaystyle H} . More specifically, define a function h ( x ) {\displaystyle h(\mathbf {x} )} of the form h ( x ) = H x . {\displaystyle h(\mathbf {x} )=H\mathbf {x} .} The function h {\displaystyle h} is called the observation function or, in the inverse problems context, the forward operator.
Machine intelligence State space search Machine_intelligence > Tools > Search and optimization > State space search State space search searches through a tree of possible states to try to find a goal state. For example, Planning algorithms search through trees of goals and subgoals, attempting to find a path to a target goal, a process called means-ends analysis.Simple exhaustive searches are rarely sufficient for most real-world problems: the search space (the number of places to search) quickly grows to astronomical numbers. The result is a search that is too slow or never completes. "Heuristics" or "rules of thumb" can help to prioritize choices that are more likely to reach a goal.Adversarial search is used for game-playing programs, such as chess or go. It searches through a tree of possible moves and counter-moves, looking for a winning position.
Hang (computing) Summary Hang_(computing) Many modern operating systems provide the user with a means to forcibly terminate a hung program without rebooting or logging out; some operating systems, such as those designed for mobile devices, may even do this automatically. In more severe hangs affecting the whole system, the only solution might be to reboot the machine, usually by power cycling with an off/on or reset button. A hang differs from a crash, in which the failure is immediate and unrelated to the responsiveness of inputs.
Image of a function Other terminology Inverse_image > Notation for image and inverse image > Other terminology An alternative notation for f {\displaystyle f} used in mathematical logic and set theory is f ″ A . {\displaystyle f\,''A.} Some texts refer to the image of f {\displaystyle f} as the range of f , {\displaystyle f,} but this usage should be avoided because the word "range" is also commonly used to mean the codomain of f . {\displaystyle f.}
Carcinogenesis Oncogenes Neoplastic_transformation > Mechanisms > Oncogenes Oncogenes often produce mitogens, or are involved in transcription of DNA in protein synthesis, which creates the proteins and enzymes responsible for producing the products and biochemicals cells use and interact with. Mutations in proto-oncogenes, which are the normally quiescent counterparts of oncogenes, can modify their expression and function, increasing the amount or activity of the product protein. When this happens, the proto-oncogenes become oncogenes, and this transition upsets the normal balance of cell cycle regulation in the cell, making uncontrolled growth possible.
User-defined function Databases User-defined_function > Databases Note that the function name does not have to be unique, considering overloaded functions. Some SQL implementations require that function names are unique within a database, and overloaded functions are not allowed. Determinism - specifies whether the function is deterministic or not.
Execution semantics Computer languages vs programming languages Programming_Language > Definitions > Computer languages vs programming languages ANSI/ISO SQL-92 and Charity are examples of languages that are not Turing complete, yet are often called programming languages. However, some authors restrict the term "programming language" to Turing complete languages.Another usage regards programming languages as theoretical constructs for programming abstract machines and computer languages as the subset thereof that runs on physical computers, which have finite hardware resources. John C. Reynolds emphasizes that formal specification languages are just as much programming languages as are the languages intended for execution. He also argues that textual and even graphical input formats that affect the behavior of a computer are programming languages, despite the fact they are commonly not Turing-complete, and remarks that ignorance of programming language concepts is the reason for many flaws in input formats.
Neurophilosophy Views on computation Neurophilosophy > Computation and representation in the brain > Views on computation Note from the earlier discussion of representation that both the Churchlands' connectionist systems and Fodor's symbolic systems use this notion of computation. In fact, Fodor is famously credited as saying "No computation without representation". Computational states can be individuated by an externalized appeal to content in a broad sense (i.e. the object in the external world) or by internalist appeal to the narrow sense content (content defined by the properties of the system).
Law of definite proportions Non-stoichiometric compounds and isotopes Law_of_definite_proportions > Non-stoichiometric compounds and isotopes This variation is used in radiometric dating since astronomical, atmospheric, oceanic, crustal and deep Earth processes may concentrate some environmental isotopes preferentially. With the exception of hydrogen and its isotopes, the effect is usually small, but is measurable with modern-day instrumentation. Many natural polymers vary in composition (for instance DNA, proteins, carbohydrates) even when "pure".
Bijection, injection and surjection Summary Bijection,_injection_and_surjection Notationally: ∀ x , x ′ ∈ X , f ( x ) = f ( x ′ ) ⟹ x = x ′ , {\displaystyle \forall x,x'\in X,f(x)=f(x')\implies x=x',} or, equivalently (using logical transposition), ∀ x , x ′ ∈ X , x ≠ x ′ ⟹ f ( x ) ≠ f ( x ′ ) . {\displaystyle \forall x,x'\in X,x\neq x'\implies f(x)\neq f(x').} The function is surjective, or onto, if each element of the codomain is mapped to by at least one element of the domain.
Cosmic Background Explorer Spacecraft Cosmic_Background_Explorer > Spacecraft These wheels were used to carry an angular momentum opposite that of the entire spacecraft in order to create a zero net angular momentum system. The orbit would prove to be determined based on the specifics of the spacecraft's mission. The overriding considerations were the need for full sky coverage, the need to eliminate stray radiation from the instruments and the need to maintain thermal stability of the dewar and the instruments.
Multiple quantum well Summary Quantum_well A quantum well is a potential well with only discrete energy values. The classic model used to demonstrate a quantum well is to confine particles, which were initially free to move in three dimensions, to two dimensions, by forcing them to occupy a planar region. The effects of quantum confinement take place when the quantum well thickness becomes comparable to the de Broglie wavelength of the carriers (generally electrons and holes), leading to energy levels called "energy subbands", i.e., the carriers can only have discrete energy values. A wide variety of electronic quantum well devices have been developed based on the theory of quantum well systems.
Throttleable rocket engine Chemistry Chemical_rocket > Chemistry Consequently, it is generally desirable for the exhaust species to be as simple as possible, with a diatomic molecule composed of light, abundant atoms such as H2 being ideal in practical terms. However, in the case of a chemical rocket, hydrogen is a reactant and reducing agent, not a product. An oxidizing agent, most typically oxygen or an oxygen-rich species, must be introduced into the combustion process, adding mass and chemical bonds to the exhaust species.
Cutaneous manifestations of COVID-19 Summary Cutaneous_manifestations_of_COVID-19 The major dermatologic patterns identified in individuals with COVID-19 are urticarial rash, confluent erythematous/morbilliform rash, papulovesicular exanthem, chilbain-like acral pattern, livedo reticularis and purpuric "vasculitic" pattern. Chilblains and Multisystem inflammatory syndrome in children are also cutaneous manifestations of COVID-19.Hyperactive immune responses in COVID-19 patients can contribute to the induction "cytokine storm" (in particular, IL-6); these cytokines could enter the skin and trigger dermal dendritic cells, lymphocytes, macrophages, mast cells, and neutrophils, and can assist in the development of lesions such as maculopapular rash. This representation of cutaneous lesion has been described earlier in diseases having an overactive immune response and excessive cytokine release (example, systemic lupus erythematosus, adult Still's disease, and antiphospholipid syndrome).
Quantum-optical spectroscopy Relation to semiconductor quantum optics Quantum-optical_spectroscopy > Relation to semiconductor quantum optics In the same way, quantum-dot lasers may exhibit unusual changes in the conditional probability to emit a photon when already one photon is emitted; this effect can be measured in the so-called g2 correlation. One interesting possibility for quantum-optical spectroscopy is to pump quantum dots with quantum light to control their light emission more precisely.Quantum-dot microcavity investigations have progressed rapidly ever since the experimental demonstration of vacuum Rabi splitting between a single dot and a cavity resonance. This regime can be understood on the basis of the Jaynes–Cummings model while the semiconductor aspects provide many new physical effects due to the electronic coupling with the lattice vibrations.
Biology of depression Subgenual cingulate Biology_of_depression > Neuroanatomy > Brain regions > Subgenual cingulate Studies have shown that Brodmann area 25, also known as subgenual cingulate, is metabolically overactive in treatment-resistant depression. This region is extremely rich in serotonin transporters and is considered as a governor for a vast network involving areas like hypothalamus and brain stem, which influences changes in appetite and sleep; the amygdala and insula, which affect the mood and anxiety; the hippocampus, which plays an important role in memory formation; and some parts of the frontal cortex responsible for self-esteem. Thus disturbances in this area or a smaller than normal size of this area contributes to depression. Deep brain stimulation has been targeted to this region in order to reduce its activity in people with treatment resistant depression. : 576–578
Snubber capacitor Power film capacitors Polymer_film_capacitor > Applications > Power film capacitors As pulse discharge capacitors, they are useful in applications with reversing voltages, such as in magnetizing equipment. The scope of application for DC capacitors is similarly diverse. Smoothing capacitors are used to reduce the AC component of fluctuating DC voltage (such as in power supplies for radio and television transmitters), and for high voltage testing equipment, DC controllers, measurement and control technology and cascaded circuits for generation of high DC voltage.
Chromosomal aberrations Acquired chromosome abnormalities Cytogenetic_abnormality > Acquired chromosome abnormalities Most cancers, if not all, could cause chromosome abnormalities, with either the formation of hybrid genes and fusion proteins, deregulation of genes and overexpression of proteins, or loss of tumor suppressor genes (see the "Mitelman Database" and the Atlas of Genetics and Cytogenetics in Oncology and Haematology,). Furthermore, certain consistent chromosomal abnormalities can turn normal cells into a leukemic cell such as the translocation of a gene, resulting in its inappropriate expression.
Machine learning in earth sciences Optimal machine learning algorithm Machine_learning_in_earth_sciences > Optimal machine learning algorithm For example, the lithological mapping of gold-bearing granite-greenstone rocks in Hutti, India with AVIRIS-NG hyperspectral data, shows more than 10% difference in overall accuracy between using Support Vector Machine (SVM) and random forest. Some algorithms can also reveal some important information. 'White-box models' are transparent models in which the results and methodologies can be easily explained, while 'black-box' models are the opposite.
Rule based DFM analysis for forging Deviations of forms Rule_based_DFM_analysis_for_forging > Hot forging > Deviations of forms The tolerances for lengths, widths, heights, and thicknesses cover IL only the diligences of dimensions, but also the deviations of form which are: a) Out of round, b) Deviations from cylindricity c) Deviations from parallelism, and d) Other deviations from the specified contour. The deviations arc not to exceed the limits given by the tolerances. In extreme cases they may cover the whole fields of tolerances unless other is agreed to between the supplier and purchaser. Where restrictions deviations of form have been agreed upon, this shall be noted on the drawing.
Meningeal carcinomatosis Chemotherapy Neoplastic_meningitis > Treatment > Chemotherapy Chemotherapy is injected directly into the cerebrospinal fluid, either by lumbar puncture (“spinal tap”) or through a surgically implanted device called an Ommaya reservoir. Intrathecal Therapy is preferred since intravenous chemotherapy do not penetrate the BBB. The most common chemicals used are liposomal cytarabine (DepoCyte) and intrathecal methotrexate (MTX). The downside of a spinal tap diagnosis is that while it is highly accurate and reliable, it can also report false-negative results.
Phytoplankton Ecology Planktonic_algae > Ecology Phytoplankton obtain energy through the process of photosynthesis and must therefore live in the well-lit surface layer (termed the euphotic zone) of an ocean, sea, lake, or other body of water. Phytoplankton account for about half of all photosynthetic activity on Earth. Their cumulative energy fixation in carbon compounds (primary production) is the basis for the vast majority of oceanic and also many freshwater food webs (chemosynthesis is a notable exception). While almost all phytoplankton species are obligate photoautotrophs, there are some that are mixotrophic and other, non-pigmented species that are actually heterotrophic (the latter are often viewed as zooplankton).
Split attention effect A visual example of split attention Split_attention_effect > A visual example of split attention Consider the graphic below from Tarmizi and Sweller. They used these graphics to compare the learning that takes place given split attention conditions. Each is a possibility of how one might arrange graphical material within a lesson. Ward and Sweller advise instructional designers to be careful when they direct a learner's attention.
Quantum fiction Emerging genre Quantum_fiction > Emerging genre He stated he realized his method of storytelling, the technique, not content, was quantum fiction.Quantum theory postulates a surreal view of things that does not correspond with the way we generally experience the world, and which is not explained by mechanical laws of the physical world. Unlike science fiction, which the California Department of Education defines as a "story based on impact of actual, imagined, or potential science, usually set in the future or on other planets," quantum fiction is a literary technique that relies more on literary fiction than genre writing. It is unlimited to content or subject, and authors craft ordinary characters through sensibilities and perception affected by the quantum view of the world.
Berman–Hartmanis conjecture Evidence Berman–Hartmanis_conjecture > Evidence As evidence towards the conjecture, Agrawal et al. (1997) showed that an analogous conjecture with a restricted type of reduction is true: every two languages that are complete for NP under AC0 many-one reductions have an AC0 isomorphism.Agrawal & Watanabe (2009) showed that, if there exist one-way functions that cannot be inverted in polynomial time on all inputs, but if every such function has a small but dense subset of inputs on which it can be inverted in P/poly (as is true for known functions of this type) then every two NP-complete languages have a P/poly isomorphism. And Fenner, Fortnow & Kurtz (1992) found an oracle machine model in which the analogue to the isomorphism conjecture is true.Evidence against the conjecture was provided by Joseph & Young (1985) and Kurtz, Mahaney & Royer (1995). Joseph and Young introduced a class of NP-complete problems, the k-creative sets, for which no p-isomorphism to the standard NP-complete problems is known. Kurtz et al. showed that in oracle machine models given access to a random oracle, the analogue of the conjecture is not true: if A is a random oracle, then not all sets complete for NPA have isomorphisms in PA.
Minority carrier lifetime Solar cells Minority_carrier_lifetime > Applications > Solar cells A solar cell is an electrical device in which a semiconductor is exposed to light that is converted into electricity through the photovoltaic effect. Electrons are either excited through the absorption of light, or if the band-gap energy of the material can be bridged, electron-hole pairs are created. Simultaneously, a voltage potential is created. The charge carriers within the solar cell move through the semiconductor in order to cancel said potential, which is the drifting force that moves the electrons.
Antigen transfer in the thymus Summary Antigen_transfer_in_the_thymus Antigen transfer in the thymus is the transmission of self-antigens between thymic antigen-presenting cells which contributes to the establishment of T cell central tolerance.Thymus represents an origin of T cell development and its responsibility is to select functional but also safe T cells which will not attack self tissues. Self-harmful T cells, further referred to as autoreactive T cells, originate in the thymus because of the stochastic process called V(D)J recombination which conducts the generation of T cell receptors (TCRs) and enables their limitless variability. Two processes of central tolerance take place in thymic medulla, namely clonal deletion (recessive tolerance) and T Regulatory cells selection (dominant tolerance) which force autoreactive T cells to apoptosis or skew them into suppressor T regulatory cells (TRegs), respectively, in order to protect body against manifestations of autoimmunity.These processes are mediated especially by unique subset of stromal cells called Medullary thymic epithelial cells (mTECs) via presentation of Tissue restricted antigens (TRAs) that represent self tissues from almost all parts of the body.
Variational methods in general relativity Summary Variational_methods_in_general_relativity Variational methods in general relativity refers to various mathematical techniques that employ the use of variational calculus in Einstein's theory of general relativity. The most commonly used tools are Lagrangians and Hamiltonians and are used to derive the Einstein field equations.
Processing element G Processing_elements > G graphics hardware Graphics Processing Unit (GPU) A specialized processor designed for the purpose of creating images and animations and displaying them on a computer screen, independent of the CPU and onboard video memory.
Supervised classification Algorithms Supervised_classification > Algorithm choice > Algorithms The most widely used learning algorithms are: Support-vector machines Linear regression Logistic regression Naive Bayes Linear discriminant analysis Decision trees K-nearest neighbor algorithm Neural networks (Multilayer perceptron) Similarity learning
Medication Modern pharmacology Therapeutic_agents > History > Modern pharmacology In the 1930s, antibiotics emerged: first sulfa drugs, then penicillin and other antibiotics. Drugs increasingly became "the center of medical practice". : 22 In the 1950s, other drugs emerged including corticosteroids for inflammation, rauvolfia alkaloids as tranquilizers and antihypertensives, antihistamines for nasal allergies, xanthines for asthma, and typical antipsychotics for psychosis.
Aristotle Potentiality and actuality Aristotle > Theoretical philosophy > Metaphysics > Substance > Potentiality and actuality Concerning the nature of change (kinesis) and its causes, as he outlines in his Physics and On Generation and Corruption (319b–320a), he distinguishes coming-to-be (genesis, also translated as 'generation') from: growth and diminution, which is change in quantity; locomotion, which is change in space; and alteration, which is change in quality.Coming-to-be is a change where the substrate of the thing that has undergone the change has itself changed. In that particular change he introduces the concept of potentiality (dynamis) and actuality (entelecheia) in association with the matter and the form. Referring to potentiality, this is what a thing is capable of doing or being acted upon if the conditions are right and it is not prevented by something else. For example, the seed of a plant in the soil is potentially (dynamei) a plant, and if it is not prevented by something, it will become a plant.
Wave particle duality Classical waves and particles Wave_nature > Classical waves and particles These particles arrive one at time, randomly, but build up a pattern. The probability that experiments will measure particles at any point in space and time behaves similar to a classical wave. Experiments can be designed to exhibit diffraction and interference of the probability wave. Thus statistically large numbers of the random particle appearances can display wave-like properties. Similar equations govern collective excitations called quasiparticles.
Machine learning Regression analysis Machine_learning > Approaches > Models > Regression analysis Regression analysis encompasses a large variety of statistical methods to estimate the relationship between input variables and their associated features. Its most common form is linear regression, where a single line is drawn to best fit the given data according to a mathematical criterion such as ordinary least squares. The latter is often extended by regularization methods to mitigate overfitting and bias, as in ridge regression. When dealing with non-linear problems, go-to models include polynomial regression (for example, used for trendline fitting in Microsoft Excel), logistic regression (often used in statistical classification) or even kernel regression, which introduces non-linearity by taking advantage of the kernel trick to implicitly map input variables to higher-dimensional space.
Koopman–von Neumann wavefunction Quantum analogy Koopman–von_Neumann_classical_mechanics > Quantum analogy In fact, the time evolution of the Wigner function approaches, in the classical limit, the time evolution of the KvN wavefunction of a classical particle. However, a mathematical resemblance to quantum mechanics does not imply the presence of hallmark quantum effects. In particular, impossibility of double-slit experiment and Aharonov–Bohm effect are explicitly demonstrated in the KvN framework.
Quantum cosmology Summary Quantum_cosmology Quantum cosmology is the attempt in theoretical physics to develop a quantum theory of the universe. This approach attempts to answer open questions of classical physical cosmology, particularly those related to the first phases of the universe. Classical cosmology is based on Albert Einstein's general theory of relativity (GTR or simply GR) which describes the evolution of the universe very well, as long as you do not approach the Big Bang.
Robot ethics Law Robot_ethics > Law With contemporary technological issues emerging as society pushes on, one topic that requires thorough thought is robot ethics concerning the law. Academics have been debating the process of how a government could go about creating legislation with robot ethics and law. A pair of scholars that have been asking these questions are Neil M. Richards Professor of Law at Washington University School of Law as well as, William D. Smart Associate Professor of Computer Science at McKelvey School of Engineering. In their paper "How Should Robots Think About Law" they make four main claims concerning robot ethics and law.
Population collapse Long-term future trends Population_collapse > Long-term future trends A long-term population decline is typically caused by sub-replacement fertility, coupled with a net immigration rate that fails to compensate for the excess of deaths over births. A long-term decline is accompanied by population aging and creates an increase in the ratio of retirees to workers and children. When a sub-replacement fertility rate remains constant, population decline accelerates over the long term.Because of the global decline in the fertility rate, projections of future global population show a marked slowing of population growth and the possibility of long-term decline.The table below summarizes the United Nations projections for future population growth. Any such long-term projections are necessarily highly speculative.
Perpetual motion machine of the first kind Apparent perpetual motion machines Perpetual_motion_machine_of_the_second_kind > Apparent perpetual motion machines As a perpetual motion machine can only be defined in a finite isolated system with discrete parameters, and since true isolated systems do not exist (among other things, due to quantum uncertainty and Tarski's/ Gödel's theorems), "perpetual motion" in the context of this article is better defined as a "perpetual motion machine" because a machine is a "A device that directs and controls energy, often in the form of movement or electricity, to produce a certain effect" whereas "motion" is simply movement (think Brownian Motion). Distinctions aside, on the macro scale, there are concepts and technical drafts that propose "perpetual motion", but on closer analysis it is revealed that they actually "consume" some sort of natural resource or latent energy, such as the phase changes of water or other fluids or small natural temperature gradients, or simply cannot sustain indefinite operation. In general, extracting work from these devices is impossible.
Endoscope Rod-lens endoscopes Endoscope > History > Rod-lens endoscopes The tiny lenses of a conventional system required supporting rings that would obscure the bulk of the lens' area. They were also hard to manufacture and assemble and optically nearly useless.The elegant solution that Hopkins invented was to fill the air-spaces between the 'little lenses' with rods of glass. These rods fitted exactly the endoscope's tube making them self-aligning and requiring of no other support.
Facebook diplomacy Facebook diplomacy Digital_diplomacy > Facebook diplomacy Facebook diplomacy is a user created hybrid of public diplomacy and citizen diplomacy as applied in the Facebook social networking platform. After some earlier informal use the term Facebook diplomacy was described at a New York conference on social networking and technology in December 2008. During the December conference in New York, the United States Undersecretary of Public Diplomacy, James Glassman said, "New technology gives the United States and other free nations a significant advantage over terrorists."
Ring of generic matrices Summary Generic_matrix_ring In algebra, a generic matrix ring is a sort of a universal matrix ring.
Transcription translation feedback loop Mammals Transcription_translation_feedback_loop > Prominent models > Mammals Knocking out either mPer1 or mPer2 causes a change in period, with mPer1 knockouts free-running with a shorter period and mPer2 knockouts free running with a longer period compared to the original tau before eventually becoming arrhythmic. Similarly, mCry1 knockouts result in a shortened period and mCry2 knockouts result in a lengthened period, with a double mCry1/mCry2 knockouts result in arrhythmicity.There are also secondary loops in mammals, although they are more complex than those seen in Drosophila. Like CWO in Drosophila, Deleted in esophageal cancer1,2 (Dec1 Dec2) repress mPer expression by binding E-boxes which prevents CLOCK-BMAL1 from binding their targets.
Phagocytic cell Phagocytosis Phagocytic_cells > Phagocytosis Opsonin receptors increase the phagocytosis of bacteria that have been coated with immunoglobulin G (IgG) antibodies or with complement. "Complement" is the name given to a complex series of protein molecules found in the blood that destroy cells or mark them for destruction. Scavenger receptors bind to a large range of molecules on the surface of bacterial cells, and Toll-like receptors—so called because of their similarity to well-studied receptors in fruit flies that are encoded by the Toll gene—bind to more specific molecules including foreign DNA and RNA. Binding to Toll-like receptors increases phagocytosis and causes the phagocyte to release a group of hormones that cause inflammation.
Material Sciences Fundamentals Material_Engineering > Fundamentals The basis of materials science is studying the interplay between the structure of materials, the processing methods to make that material, and the resulting material properties. The complex combination of these produce the performance of a material in a specific application. Many features across many length scales impact material performance, from the constituent chemical elements, its microstructure, and macroscopic features from processing. Together with the laws of thermodynamics and kinetics materials scientists aim to understand and improve materials.
Color coding in data visualization Grayscale, an important tool for visualization of data Color_coding_in_data_visualization > Grayscale, an important tool for visualization of data It enables calculation of any number of equal perceptible differences (nEPD) as small as the threshold of visibility, or of any suprathreshold magnitude. The unit size of nEPD is three or four times the absolute threshold of visibility for luminance change. This nEPD unit is “just noticeable at a glance” with free viewing of an electronic display.The Whittle calculation is unusual (among grayscale formulae) in four ways.
Protein nuclear magnetic resonance Dynamics Nuclear_magnetic_resonance_spectroscopy_of_proteins > Dynamics However, since nitrogen atoms are found mainly in the backbone of a protein, the results mainly reflect the motions of the backbone, which is the most rigid part of a protein molecule. Thus, the results obtained from nitrogen-15 relaxation measurements may not be representative of the whole protein. Therefore, techniques utilising relaxation measurements of carbon-13 and deuterium have recently been developed, which enables systematic studies of motions of the amino acid side-chains in proteins.
Solvent models Implicit models Solvent_models > Implicit models The solute's charge distribution meets the continuous dielectric field at the surface of the cavity and polarizes the surrounding medium, which causes a change in the polarization on the solute. This defines the reaction potential, a response to the change in polarization. This recursive reaction potential is then iterated to self-consistency.
Renormalization Summary Renormalization Initially viewed as a suspect provisional procedure even by some of its originators, renormalization eventually was embraced as an important and self-consistent actual mechanism of scale physics in several fields of physics and mathematics. Today, the point of view has shifted: on the basis of the breakthrough renormalization group insights of Nikolay Bogolyubov and Kenneth Wilson, the focus is on variation of physical quantities across contiguous scales, while distant scales are related to each other through "effective" descriptions. All scales are linked in a broadly systematic way, and the actual physics pertinent to each is extracted with the suitable specific computational techniques appropriate for each. Wilson clarified which variables of a system are crucial and which are redundant. Renormalization is distinct from regularization, another technique to control infinities by assuming the existence of new unknown physics at new scales.
Cellular Biology Cell cycle checkpoints and DNA damage repair system Cellular_Biology > Cell cycle checkpoints and DNA damage repair system There are major events that happen during a cell cycle. The processes that happen in the cell cycle include cell development, replication and segregation of chromosomes. The cell cycle checkpoints are surveillance systems that keep track of the cell cycle's integrity, accuracy, and chronology.
Manufacturing Execution Systems Relationship with Level 0, 1, 2 systems Manufacturing_Execution_System > Relationship with other systems > Relationship with Level 0, 1, 2 systems Systems acting on ISA-95 Level 2 are supervisory control and data acquisition (SCADA), programmable logic controllers (PLC), distributed control systems (DCS) and building automation systems (BAS). Information flows between MES and these process control systems are roughly similar: To PLCs: work instructions, recipes, set points From PLCs: process values, alarms, adjusted set points, production resultsMost MES systems include connectivity as part of their product offering. Direct communication of plant floor equipment data is established by connecting to the PLC.
Direct reporting unit Group Direct_reporting_unit > Organizational types > Group Made up of several squadrons and typically commanded by a colonel (O-6). Second in command to the group commander is the deputy group commander, who is also a colonel or lieutenant colonel (O-5); in some cases, this role may be performed by a designated civilian, typically at the GS-15 level, with the alternative title of deputy group director. The senior enlisted member of a group is known as the group senior enlisted leader (formerly group superintendent). This position can only be held by a chief master sergeant (E-9).
Circular cumulative causation Summary Circular_cumulative_causation Circular cumulative causation is a theory developed by Swedish economist Gunnar Myrdal who applied it systematically for the first time in 1944 (Myrdal, G. (1944), An American Dilemma: The Negro Problem and Modern Democracy, New York: Harper). It is a multi-causal approach where the core variables and their linkages are delineated.
List of relativistic equations Postulates of Special Relativity List_of_relativistic_equations > Postulates of Special Relativity Thus, a more accurate description would refer to c 0 {\displaystyle c_{0}} rather than the speed of light per se. However, light and other massless particles do theoretically travel at c 0 {\displaystyle c_{0}} under vacuum conditions and experiment has nonfalsified this notion with fairly high precision.
Stomach pump Technique Stomach_pump > Technique Gastric lavage involves the passage of a tube (such as an Ewald tube) via the mouth or nose down into the stomach followed by sequential administration and removal of small volumes of liquid. The placement of the tube in the stomach must be confirmed by pH testing a small amount of aspirated stomach contents, or x-ray. This is to ensure the tube is not in the lungs. In adults, small amounts of warm water or saline are administered and, via a siphoning action, removed again.
Organic synthesis Total synthesis Synthesis_of_organic_chemicals > Total synthesis For more complex molecules, a convergent synthetic approach may be preferable, one that involves individual preparation of several "pieces" (key intermediates), which are then combined to form the desired product. Convergent synthesis has the advantage of generating higher yield, compared to linear synthesis. Robert Burns Woodward, who received the 1965 Nobel Prize for Chemistry for several total syntheses (e.g., his 1954 synthesis of strychnine), is regarded as the father of modern organic synthesis. Some latter-day examples include Wender's, Holton's, Nicolaou's, and Danishefsky's total syntheses of the anti-cancer therapeutic, paclitaxel (trade name, Taxol).
Thermometric titration Titration of acid mixtures Thermometric_titration > Acid–base titrations > Titration of acid mixtures Mixtures of complex acids can be resolved by thermometric titration with standard NaOH in aqueous solution. In a mixture of nitric, acetic and phosphoric acids used in the fabrication of semi-conductors, three endpoints could be predicted on the basis of the dissociation constants of the acids: The key to determine the amount of each acid present in the mixture is the ability to obtain an accurate value for the amount of phosphoric acid present, as revealed by titration of the third proton of H3PO4. Figure 10 illustrates a titration plot of this mixture, showing 3 sharp endpoints.
Velocity (character) Fictional character biography Velocity_(character) > Fictional character biography Primarily, in Carin's case, the Brain Box allowed her to run faster without overloading her brain or body with the chemicals naturally produced by the body with any muscle movement. It also allowed her to make directional adjustments to avoid obstacles when travelling at high speeds. Velocity had her own limited series in 1995; she is assisted in part by Savage Dragon.
Algorithmic number theory Summary Algorithmic_number_theory In mathematics and computer science, computational number theory, also known as algorithmic number theory, is the study of computational methods for investigating and solving problems in number theory and arithmetic geometry, including algorithms for primality testing and integer factorization, finding solutions to diophantine equations, and explicit methods in arithmetic geometry. Computational number theory has applications to cryptography, including RSA, elliptic curve cryptography and post-quantum cryptography, and is used to investigate conjectures and open problems in number theory, including the Riemann hypothesis, the Birch and Swinnerton-Dyer conjecture, the ABC conjecture, the modularity conjecture, the Sato-Tate conjecture, and explicit aspects of the Langlands program.
Tertiary hydrogen bond Summary Resonance-assisted_hydrogen_bond Hydrogen bonds are responsible for holding materials such as paper and felted wool together, and for causing separate sheets of paper to stick together after becoming wet and subsequently drying. The hydrogen bond is responsible for many of the physical and chemical properties of compounds of N, O, and F that seem unusual compared with other similar structures. In particular, intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C) compared to the other group-16 hydrides that have much weaker hydrogen bonds. Intramolecular hydrogen bonding is partly responsible for the secondary and tertiary structures of proteins and nucleic acids.
Event Stream Processing Summary Stream_Processing In computer science, stream processing (also known as event stream processing, data stream processing, or distributed stream processing) is a programming paradigm which views streams, or sequences of events in time, as the central input and output objects of computation. Stream processing encompasses dataflow programming, reactive programming, and distributed data processing. Stream processing systems aim to expose parallel processing for data streams and rely on streaming algorithms for efficient implementation. The software stack for these systems includes components such as programming models and query languages, for expressing computation; stream management systems, for distribution and scheduling; and hardware components for acceleration including floating-point units, graphics processing units, and field-programmable gate arrays.The stream processing paradigm simplifies parallel software and hardware by restricting the parallel computation that can be performed.
Advanced process control Types of Advanced Process Control Advanced_process_control > Types of Advanced Process Control Inferentials can be utilized in place of actual online analyzers, whether for operator information, cascaded to base-layer process controllers, or multivariable controller CVs. Sequential control refers to discontinuous time- and event-based automation sequences that occur within continuous processes. These may be implemented as a collection of time and logic function blocks, a custom algorithm, or using a formalized Sequential function chart methodology. Intelligent control is a class of control techniques that use various artificial intelligence computing approaches like neural networks, Bayesian probability, fuzzy logic, machine learning, evolutionary computation and genetic algorithms.
Derived quantity Level Derived_quantity > Derived quantities > Logarithmic quantities > Level The level of a quantity is defined as the logarithm of the ratio of the quantity with a stated reference value of that quantity. Within the ISQ it is differently defined for a root-power quantity (also known by the deprecated term field quantity) and for a power quantity. It is not defined for ratios of quantities of other kinds. Within the ISQ, all levels are treated as derived quantities of dimension 1. Several units for levels are defined by the SI and classified as "non-SI units accepted for use with the SI units".An example of level is sound pressure level, with the unit of decibel.
Vector autoregression Definition Vector_autoregression > Specification > Definition The vector's components are referred to as yi,t, meaning the observation at time t of the i th variable. For example, if the first variable in the model measures the price of wheat over time, then y1,1998 would indicate the price of wheat in the year 1998. VAR models are characterized by their order, which refers to the number of earlier time periods the model will use.
Enolase superfamily Summary Enolase_superfamily The enolase superfamily is a superfamily of enzymes, members of which catalyse a range of reactions. The enolase superfamily includes enzymes that catalyse a wide variety of reactions and performing diverse roles in metabolism. However, the reactions catalysed share the common chemical step of abstraction of a proton from a carbon adjacent to a carboxylic acid and a requirement of a divalent metal ion. This diversity of functions is in contrast to many families of enzymes whose members catalyse similar chemical reactions on different substrates.
82 (number) In science 82_(number) > In science The atomic number of lead. The sixth magic number. Messier 82, a starburst galaxy in the constellation Ursa Major. The New General Catalogue object NGC 82, a single star in the constellation Andromeda.
Neutral density filter Summary ND_filter In photography and optics, a neutral-density filter, or ND filter, is a filter that reduces or modifies the intensity of all wavelengths, or colors, of light equally, giving no changes in hue of color rendition. It can be a colorless (clear) or grey filter, and is denoted by Wratten number 96. The purpose of a standard photographic neutral-density filter is to reduce the amount of light entering the lens.
Congenital adrenal hyperplasia due to 21-hydroxylase deficiency Application of dexamethasone in prenatal treatment Congenital_adrenal_hyperplasia_due_to_21-hydroxylase_deficiency > Treatment > Prenatal treatment > Application of dexamethasone in prenatal treatment If so, dexamethasone is continued for the remainder of the pregnancy at a dose of about 1 mg daily.Most mothers who have followed this treatment plan have experienced at least mild cushingoid effects from the glucocorticoid but have borne daughters whose genitalia are much less virilized.Dexamethasone is used as an off-label early prenatal treatment for the symptoms of CAH in female fetuses, but it does not treat the underlying congenital disorder. A 2007 Swedish clinical trial found that treatment may cause cognitive and behavioural defects, but the small number of test subjects means the study cannot be considered definitive. A 2012 American study found no negative short-term outcomes, but "lower cognitive processing in CAH girls and women with long-term DEX exposure."
Residuated mapping Summary Residuated_mapping In mathematics, the concept of a residuated mapping arises in the theory of partially ordered sets. It refines the concept of a monotone function. If A, B are posets, a function f: A → B is defined to be monotone if it is order-preserving: that is, if x ≤ y implies f(x) ≤ f(y). This is equivalent to the condition that the preimage under f of every down-set of B is a down-set of A. We define a principal down-set to be one of the form ↓{b} = { b' ∈ B: b' ≤ b }.
ATM protein Summary ATM_protein ATM serine/threonine kinase or Ataxia-telangiectasia mutated, symbol ATM, is a serine/threonine protein kinase that is recruited and activated by DNA double-strand breaks (canonical pathway), oxidative stress, topoisomerase cleavage complexes, splicing intermediates, R-loops and in some cases by single-strand DNA breaks. It phosphorylates several key proteins that initiate activation of the DNA damage checkpoint, leading to cell cycle arrest, DNA repair or apoptosis. Several of these targets, including p53, CHK2, BRCA1, NBS1 and H2AX are tumor suppressors. In 1995, the gene was discovered by Yosef Shiloh who named its product ATM since he found that its mutations are responsible for the disorder ataxia–telangiectasia. In 1998, the Shiloh and Kastan laboratories independently showed that ATM is a protein kinase whose activity is enhanced by DNA damage.
Shape factor (image analysis and microscopy) Circularity Shape_factor_(image_analysis_and_microscopy) > Circularity Another very common shape factor is the circularity (or isoperimetric quotient), a function of the perimeter P and the area A: f circ = 4 π A P 2 {\displaystyle f_{\text{circ}}={\frac {4\pi A}{P^{2}}}} The circularity of a circle is 1, and much less than one for a starfish footprint. The reciprocal of the circularity equation is also used, such that fcirc varies from one for a circle to infinity.
Homing torpedo Flywheel Homing_torpedo > Energy sources > Flywheel The Howell torpedo used by the US Navy in the late 19th century featured a heavy flywheel that had to be spun up before launch. It was able to travel about 400 yards (370 m) at 25 knots (46 km/h). The Howell had the advantage of not leaving a trail of bubbles behind it, unlike compressed air torpedoes. This gave the target vessel less chance to detect and evade the torpedo and avoided giving away the attacker's position. Additionally, it ran at a constant depth, unlike Whitehead models.
Temperature jump Summary Temperature_jump In more complex reaction networks, when multiple reaction steps are perturbed, then the reciprocal time constants are given by the eigenvalues of the characteristic rate equations. The ability to observe intermediate steps in a reaction pathway is one of the attractive features of this technology.Related chemical relaxation methods include pressure jump, electric field jump and pH jump. == References ==
NFKB2 Function NFKB2 > Function NF-κB has been detected in numerous cell types that express cytokines, chemokines, growth factors, cell adhesion molecules, and some acute phase proteins in health and in various disease states. NF-κB is activated by a wide variety of stimuli such as cytokines, oxidant-free radicals, inhaled particles, ultraviolet irradiation, and bacterial or viral products. Inappropriate activation of NF-kappa-B has been linked to inflammatory events associated with autoimmune arthritis, asthma, septic shock, lung fibrosis, glomerulonephritis, atherosclerosis, and AIDS. In contrast, complete and persistent inhibition of NF-kappa-B has been linked directly to apoptosis, inappropriate immune cell development, and delayed cell growth. For reviews, see Chen et al. (1999) and Baldwin (1996).
Transmission of COVID-19 Asymptomatic transmission Transmission_of_COVID-19 > Infectious period > Asymptomatic transmission People who are asymptomatic do not show symptoms but still are able to transmit the virus. A December 2020 systematic review estimated that about 17% of COVID-19 infections were asymptomatic (95% confidence interval of 14% to 20%; the review found that "the transmission risk from asymptomatic cases appeared to be lower than that of symptomatic cases, but there was considerable uncertainty in the extent of this." Persons with asymptomatic COVID-19 infection can have the same viral load as symptomatic and presymptomatic cases, and are able to transmit the virus. However, the infectious period of asymptomatic cases has been observed to be shorter with faster viral clearance.
Automatic programming Origin Generative_computer_programming > Origin Mildred Koss, an early UNIVAC programmer, explains: "Writing machine code involved several tedious steps—breaking down a process into discrete instructions, assigning specific memory locations to all the commands, and managing the I/O buffers. After following these steps to implement mathematical routines, a sub-routine library, and sorting programs, our task was to look at the larger programming process. We needed to understand how we might reuse tested code and have the machine help in programming. As we programmed, we examined the process and tried to think of ways to abstract these steps to incorporate them into higher-level language. This led to the development of interpreters, assemblers, compilers, and generators—programs designed to operate on or produce other programs, that is, automatic programming."
Interplanetary space travel Hohmann transfers Interplanetary_travel > Economical travel techniques > Hohmann transfers For instance it is the most common way to transfer satellites into geostationary orbit, after first being "parked" in low Earth orbit. However, the Hohmann transfer takes an amount of time similar to ½ of the orbital period of the outer orbit, so in the case of the outer planets this is many years – too long to wait. It is also based on the assumption that the points at both ends are massless, as in the case when transferring between two orbits around Earth for instance. With a planet at the destination end of the transfer, calculations become considerably more difficult.
Intermolecular interactions Hydrogen bonding Dipole–dipole_interaction > Hydrogen bonding The oxygen atom’s two lone pairs interact with a hydrogen each, forming two additional hydrogen bonds, and the second hydrogen atom also interacts with a neighbouring oxygen. Intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C) compared to the other group 16 hydrides, which have little capability to hydrogen bond. Intramolecular hydrogen bonding is partly responsible for the secondary, tertiary, and quaternary structures of proteins and nucleic acids. It also plays an important role in the structure of polymers, both synthetic and natural.
Bounded interval Terminology Closed_interval > Terminology Bounded intervals are also commonly known as finite intervals. Bounded intervals are bounded sets, in the sense that their diameter (which is equal to the absolute difference between the endpoints) is finite. The diameter may be called the length, width, measure, range, or size of the interval.
Metamorphic code Overview Metamorphic_code > Overview Metamorphic code is used by computer viruses to avoid the pattern recognition of anti-virus software. Metamorphic viruses often translate their own binary code into a temporary representation, editing the temporary representation of themselves and then translate the edited form back to machine code again. This procedure is done with the virus itself, and thus also the metamorphic engine itself undergoes changes, which means that no part of the virus stays the same. This differs from polymorphic code, where the polymorphic engine can not rewrite its own code.
Lambda-connectedness Background Lambda-connectedness > Background Random graph theory allows one to assign a probability to each edge of a graph. This method assumes, in most cases, each edge has the same probability. On the other hand, Bayesian networks are often used for inference and analysis when relationships between each pair of states/events, denoted by vertices, are known.
Surface area of a sphere Properties of the sphere Sphere > Properties > Properties of the sphere A freely floating soap bubble therefore approximates a sphere (though such external forces as gravity will slightly distort the bubble's shape). It can also be seen in planets and stars where gravity minimizes surface area for large celestial bodies. The sphere has the smallest total mean curvature among all convex solids with a given surface area.
Compiler optimizations Common themes Optimizing_compiler > Common themes To a large extent, compiler optimization techniques have the following themes, which sometimes conflict. Optimize the common case The common case may have unique properties that allow a fast path at the expense of a slow path. If the fast path is taken most often, the result is better overall performance. Avoid redundancy Reuse results that are already computed and store them for later use, instead of recomputing them.
Dibutyltin oxide Structure Dibutyltin_oxide > Structure The structure of diorganotin oxides depends on the size of the organic groups. For smaller substituents, the materials are assumed to be polymeric with five-coordinate Sn centers and 3-coordinate oxide centers. The result is a net of interconnected four-membered Sn2O2 and eight-membered Sn4O4 rings. The presence of pentacoordinate Sn centers is deduced from 119Sn NMR spectroscopy and 119Sn Mössbauer spectroscopy.
ZFS Summary ZFS > Features > Summary Can store a user-specified number of copies of data or metadata, or selected types of data, to improve the ability to recover from data corruption of important files and structures. Automatic rollback of recent changes to the file system and data, in some circumstances, in the event of an error or inconsistency. Automated and (usually) silent self-healing of data inconsistencies and write failure when detected, for all errors where the data is capable of reconstruction.
Upper Atmosphere Research Satellite Cryogenic Limb Array Etalon Spectrometer (CLAES) Upper_Atmosphere_Research_Satellite > Instruments > Chemical studies > Cryogenic Limb Array Etalon Spectrometer (CLAES) CLAES was a spectrometer that determined the concentrations and distributions of nitrogen and chlorine compounds, ozone, water vapor and methane. This platform produced the first global maps of ozone depleting chlorinated compounds. It did this by inferring the amount of gases in the atmosphere by measuring the unique infrared signature of each gas.In order to differentiate the relatively weak signature of trace gases from the background radiation in the atmosphere, CLAES had to have high resolution and sensitivity.
Beta blocker β-receptor antagonism Intrinsic_sympathomimetic_activity > β-receptor antagonism Beta blockers are readily titrated to optimal rate control in many pathologic states. The antiarrhythmic effects of beta blockers arise from sympathetic nervous system blockade—resulting in depression of sinus node function and atrioventricular node conduction, and prolonged atrial refractory periods. Sotalol, in particular, has additional antiarrhythmic properties and prolongs action potential duration through potassium channel blockade. Blockade of the sympathetic nervous system on renin release leads to reduced aldosterone via the renin–angiotensin–aldosterone system, with a resultant decrease in blood pressure due to decreased sodium and water retention.
Distinct roots Older definition Separable_polynomial > Older definition In an older definition, P(X) was considered separable if each of its irreducible factors in K is separable in the modern definition. In this definition, separability depended on the field K; for example, any polynomial over a perfect field would have been considered separable. This definition, although it can be convenient for Galois theory, is no longer in use.
Alcohol dependence Mild Alcohol_dependence > Withdrawal > Mild Nausea Vomiting Rapid heartbeat Elevated blood pressure Fatigue Body aches / tremors Anxiety / Irritability / Depression Fuzzy brain Issues with sleeping
Calculating Space Summary Rechnender_Raum Calculating Space (German: Rechnender Raum) is Konrad Zuse's 1969 book on automata theory. He proposed that all processes in the universe are computational. This view is known today as the simulation hypothesis, digital philosophy, digital physics or pancomputationalism. Zuse proposed that the universe is being computed by some sort of cellular automaton or other discrete computing machinery, challenging the long-held view that some physical laws are continuous by nature. He focused on cellular automata as a possible substrate of the computation, and pointed out that the classical notions of entropy and its growth do not make sense in deterministically computed universes. Zuse's thesis was later expanded by German computer scientist Jürgen Schmidhuber in his technical report Algorithmic Theories of Everything.
Intuitionism Infinity Intuitionism > Infinity Any infinite set that can be placed in one-to-one correspondence with the natural numbers is said to be "countable" or "denumerable". Infinite sets larger than this are said to be "uncountable".Cantor's set theory led to the axiomatic system of Zermelo–Fraenkel set theory (ZFC), now the most common foundation of modern mathematics. Intuitionism was created, in part, as a reaction to Cantor's set theory.
Management of multiple sclerosis Medications Management_of_multiple_sclerosis > Disease-modifying treatments > Medications Overall, therapy with interferon beta leads to a reduction of neuron inflammation. Moreover, it is also thought to increase the production of nerve growth factor and consequently improve neuronal survival.Glatiramer acetate is a mixture of random polymers of four amino acids which is antigenically similar to the myelin basic protein, a component of the myelin sheath of nerves with which it competes for presentation to T cells .
Fourier transformation Complex domain Fourier_uncertainty_principle > Complex domain The space of such functions of a complex variable is called the Paley—Wiener space. This theorem has been generalised to semisimple Lie groups.If f is supported on the half-line t ≥ 0, then f is said to be "causal" because the impulse response function of a physically realisable filter must have this property, as no effect can precede its cause. Paley and Wiener showed that then f̂ extends to a holomorphic function on the complex lower half-plane τ < 0 which tends to zero as τ goes to infinity. The converse is false and it is not known how to characterise the Fourier transform of a causal function.