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Glossary of probability and statistics S Glossary_of_probability_and_statistics > S There are many methods to choose on which sample to do the observations. sampling bias sampling distribution The probability distribution, under repeated sampling of the population, of a given statistic. sampling error scatter plot scale parameter significance level simple random sample Simpson's paradox skewness A measure of the asymmetry of the probability distribution of a real-valued random variable about its mean.
Bipolar transistor Function H-parameter_model > Function To minimize the fraction of carriers that recombine before reaching the collector–base junction, the transistor's base region must be thin enough that carriers can diffuse across it in much less time than the semiconductor's minority-carrier lifetime. Having a lightly doped base ensures recombination rates are low. In particular, the thickness of the base must be much less than the diffusion length of the carriers. The collector–base junction is reverse-biased, and so negligible carrier injection occurs from the collector to the base, but carriers that are injected into the base from the emitter, and diffuse to reach the collector–base depletion region, are swept into the collector by the electric field in the depletion region. The thin shared base and asymmetric collector–emitter doping are what differentiates a bipolar transistor from two separate diodes connected in series.
Monetary-disequilibrium theory History of the concept Monetary-disequilibrium_theory > History of the concept Thus, changes in the money supply will result first in a change of output in the same direction, as distinct from merely a change in prices. Consequently, an increase in the money supply will induce workers and businesses to supply more, without being fooled into doing so. In a situation where the money supply contracts, businesses will respond by laying off workers.
DNA vaccine Helper T cell responses DNA_vaccines > Immune response > Helper T cell responses DNA immunization can raise multiple TH responses, including lymphoproliferation and the generation of a variety of cytokine profiles. A major advantage of DNA vaccines is the ease with which they can be manipulated to bias the type of T-cell help towards a TH1 or TH2 response. Each type has distinctive patterns of lymphokine and chemokine expression, specific types of immunoglobulins, patterns of lymphocyte trafficking and types of innate immune responses.
Comparison of BSD operating systems Other sources Comparison_of_BSD_operating_systems > Notes and references > Other sources "OpenBSD". Operating System Technical Comparison. Retrieved 2006-06-02.
O ring Theory and design O_ring > Theory and design ISO 3601-1:2012 contains the most commonly used standard sizes, both inch and metric, worldwide. The UK also has standards sizes known as BS sizes, typically ranging from BS001 to BS932. Several other size specifications also exist.
Tantrasamgraha Synopsis of the book Tantrasamgraha > Synopsis of the book A brief account of the contents of Tantrasamgraha is presented below. A descriptive account of the contents is available in Bharatheeya Vijnana/Sastra Dhara. Full details of the contents are available in an edition of Tantrasamgraha published in the Indian Journal of History of Science. Chapter 1 (Madhyama-prakaranam): The purpose of the astronomical computation, civil and sidereal day measurements, lunar month, solar month, intercalary month, revolutions of the planets, theory of intercalation, planetary revolution in circular orbits, computation of kali days, mathematical operations like addition, subtraction, multiplication, division, squaring and determining square root, fractions, positive and negative numbers, computation of mean planets, correction for longitude, longitudinal time, positions of the planets at the beginning of Kali era, planetary apogees in degrees.
Store energy History Electrochemical_energy_storage > History Access to electricity is now a question of economics and financial viability, and not solely on technical aspects. Electric vehicles are gradually replacing combustion-engine vehicles. However, powering long-distance transportation without burning fuel remains in development.
Burton Wendroff Summary Burton_Wendroff Burton Wendroff (born March 10, 1930) is an American applied mathematician known for his contributions to the development of numerical methods for the solution of hyperbolic partial differential equations. The Lax–Wendroff method for the solution of hyperbolic PDE is named for Wendroff (as well as for Peter Lax). Wendroff is an adjunct professor at the Department of Mathematics and Statistics, University of New Mexico.
Alpha beta filter Algorithm summary Alpha_beta_filter > Filter equations > Algorithm summary Initialize. Set the initial values of state estimates x and v, using prior information or additional measurements; otherwise, set the initial state values to zero. Select values of the alpha and beta correction gains.Update. Repeat for each time step ΔT: Project state estimates x and v using equations 1 and 2 Obtain a current measurement of the output value Compute the residual r using equation 3 Correct the state estimates using equations 4 and 5 Send updated x and optionally v as the filter outputs
Flocculonodular lobe Summary Flocculonodular_lobe The flocculonodular lobe (vestibulocerebellum) is a lobe of the cerebellum consisting of the nodule and the flocculus. The two flocculi are connected to the midline structure called the nodulus by thin pedicles. It is placed on the anteroinferior surface of cerebellum.
Absorption spectra Theory Absorption_maxima > Absorption spectrum > Theory Interactions with neighboring molecules can cause shifts. For instance, absorption lines of the gas phase molecule can shift significantly when that molecule is in a liquid or solid phase and interacting more strongly with neighboring molecules. The width and shape of absorption lines are determined by the instrument used for the observation, the material absorbing the radiation and the physical environment of that material.
Domain adaptation The different types of domain adaptation Domain_randomization > The different types of domain adaptation There are several contexts of domain adaptation. They differ in the information considered for the target task. The unsupervised domain adaptation: the learning sample contains a set of labeled source examples, a set of unlabeled source examples and a set of unlabeled target examples. The semi-supervised domain adaptation: in this situation, we also consider a "small" set of labeled target examples. The supervised domain adaptation: all the examples considered are supposed to be labeled.
Computational gene A potential application: in situ diagnostics and therapy of cancer Computational_Genes > A potential application: in situ diagnostics and therapy of cancer Computational genes might be used in the future to correct aberrant mutations in a gene or group of genes that can trigger disease phenotypes. One of the most prominent examples is the tumor suppressor p53 gene, which is present in every cell, and acts as a guard to control growth. Mutations in this gene can abolish its function, allowing uncontrolled growth that can lead to cancer. For instance, a mutation at codon 249 in the p53 protein is characteristic for hepatocellular cancer.
C11H16N4O4 Summary C11H16N4O4 The molecular formula C11H16N4O4 (molar mass: 268.27 g/mol, exact mass: 268.1172 u) may refer to: Acetylcarnosine (NAC) Dexrazoxane Pentostatin
Ecological sustainability Example steps Environmental_sustainability > Transitions > Example steps Another is changing our energy use. One aspect of this is to adopt renewable energy sources. At the same time it is necessary to end subsidies to energy production through fossil fuels.
Lehmer sequence Summary Lehmer_sequence In mathematics, a Lehmer sequence is a generalization of a Lucas sequence.
Endurance test Summary Endurance_test The fatigue limit or endurance limit is the stress level below which an infinite number of loading cycles can be applied to a material without causing fatigue failure. Some metals such as ferrous alloys and titanium alloys have a distinct limit, whereas others such as aluminium and copper do not and will eventually fail even from small stress amplitudes. Where materials do not have a distinct limit the term fatigue strength or endurance strength is used and is defined as the maximum value of completely reversed bending stress that a material can withstand for a specified number of cycles without a fatigue failure.
Susceptible individual Mathematical model of susceptibility Susceptible_individual > Mathematical model of susceptibility It thus follows that the proportion of time spent as a susceptible is A/L and, in a population with a rectangular distribution, the proportion of an individual's life spent in one group is representative of the proportion of the population in that group. The advantage of estimating S in this way is that both the average age of infection and average life expectancy will be well documented, and thus the other parameters needed to calculate S will be easily at hand. The parameter S is important in the mathematical modelling of epidemics.
Overflow metabolism Summary Overflow_metabolism According to this theory, the enzymes required for respiration are more costly than those required for partial oxidation of glucose. That is, if the cell were to produce enough of these enzymes to support fast growth with respiratory metabolism, it would consume much more energy, carbon and nitrogen (per unit time) than supporting fast growth with an incompletely oxidative metabolism (e.g. fermentation). Given that cells have limited energy resources and fixed physical volume for proteins, there is thought to be a trade-off between efficient energy capture through central metabolism (i.e. respiration) and fast growth achieved through high central-metabolic fluxes (e.g. through fermentation as in yeast). As an alternative explanation, it was suggested that cells could be limited by the rate with which they can dissipate Gibbs energy to the environment. Using combined thermodynamic and stoichiometric metabolic models in flux balance analyses with (i) growth maximization as objective function and (ii) an identified limit in the cellular Gibbs energy dissipation rate, correct predictions of physiological parameters, intracellular metabolic fluxes and metabolite concentrations were achieved.
Process graph Summary Process_graph In mathematics graph theory a process graph or P-graph is a directed bipartite graph used in workflow modeling.
DNA construct Summary Artificial_plasmids Typically, the vectors used in DNA constructs contain an origin of replication, a multiple cloning site, and a selectable marker. Certain vectors can carry additional regulatory elements based on the expression system involved.DNA constructs can be as small as a few thousand base pairs (kbp) of DNA carrying a single gene, using vectors such as plasmids or bacteriophages, or as large as hundreds of kbp for large-scale genomic studies using an artificial chromosome. A DNA construct may express wildtype protein, prevent the expression of certain genes by expressing competitors or inhibitors, or express mutant proteins, such as deletion mutations or missense mutations. DNA constructs are widely adapted in molecular biology research for techniques such as DNA sequencing, protein expression, and RNA studies.
Binary search trees Successor and predecessor Binary_Search_Tree > Operations > Searching > Successor and predecessor For certain operations, given a node x {\displaystyle {\text{x}}} , finding the successor or predecessor of x {\displaystyle {\text{x}}} is crucial. Assuming all the keys of the BST are distinct, the successor of a node x {\displaystyle {\text{x}}} in BST is the node with the smallest key greater than x {\displaystyle {\text{x}}} 's key. On the other hand, the predecessor of a node x {\displaystyle {\text{x}}} in BST is the node with the largest key smaller than x {\displaystyle {\text{x}}} 's key. Following is pseudocode for finding the successor and predecessor of a node x {\displaystyle {\text{x}}} in BST.
Land vehicle Energy source Vehicle > Locomotion > Energy source Fuel cells are similar to batteries in that they convert from chemical to electrical energy, but have their own advantages and disadvantages. Electrified rails and overhead cables are a common source of electrical energy on subways, railways, trams, and trolleybuses. Solar energy is a more modern development, and several solar vehicles have been successfully built and tested, including Helios, a solar-powered aircraft.
Rigid body kinetics Newton's second law in three dimensions Rigid_body_dynamics > Rigid body in three dimensions > Newton's second law in three dimensions To consider rigid body dynamics in three-dimensional space, Newton's second law must be extended to define the relationship between the movement of a rigid body and the system of forces and torques that act on it. Newton formulated his second law for a particle as, "The change of motion of an object is proportional to the force impressed and is made in the direction of the straight line in which the force is impressed." Because Newton generally referred to mass times velocity as the "motion" of a particle, the phrase "change of motion" refers to the mass times acceleration of the particle, and so this law is usually written as where F is understood to be the only external force acting on the particle, m is the mass of the particle, and a is its acceleration vector. The extension of Newton's second law to rigid bodies is achieved by considering a rigid system of particles.
Limiting amplitude principle Formulation Limiting_amplitude_principle > Formulation To find which solution to the Helmholz equation with nonzero right-hand side Δ v ( x ) + k 2 v ( x ) = − F ( x ) , x ∈ R 3 , {\displaystyle \Delta v(x)+k^{2}v(x)=-F(x),\quad x\in \mathbb {R} ^{3},} with some fixed k > 0 {\displaystyle k>0} , corresponds to the outgoing waves, one considers the wave equation with the source term, ( Δ − ∂ t 2 ) u ( x , t ) = − F ( x ) e − i k t , t ≥ 0 , x ∈ R 3 , {\displaystyle (\Delta -\partial _{t}^{2})u(x,t)=-F(x)e^{-ikt},\quad t\geq 0,\quad x\in \mathbb {R} ^{3},} with zero initial data u ( x , 0 ) = 0 , ∂ t u ( x , 0 ) = 0 {\displaystyle u(x,0)=0,\,\partial _{t}u(x,0)=0} . A particular solution to the Helmholtz equation corresponding to outgoing waves is obtained as the limit v ( x ) = lim t → + ∞ u ( x , t ) e i k t {\displaystyle v(x)=\lim _{t\to +\infty }u(x,t)e^{ikt}} for large times.
Set-theoretic definition of natural numbers Frege and Russell Set-theoretical_definitions_of_natural_numbers > Frege and Russell However, it does not work in the axiomatic set theory ZFC nor in certain related systems, because in such systems the equivalence classes under equinumerosity are proper classes rather than sets. For enabling natural numbers to form a set, equinumerous classes are replaced by special sets, named cardinal. The simplest way to introduce cardinals is to add a primitive notion, Card(), and an axiom of cardinality to ZF set theory (without axiom of choice).Axiom of cardinality: The sets A and B are equinumerous if and only if Card(A) = Card(B) Definition: the sum of cardinals K and L such as K= Card(A) and L = Card(B) where the sets A and B are disjoint, is Card (A ∪ B).
Elementary algebra Quadratic equations Elementary_algebra > Solving algebraic equations > Quadratic equations All quadratic equations will have two solutions in the complex number system, but need not have any in the real number system. For example, x 2 + 1 = 0 {\displaystyle x^{2}+1=0} has no real number solution since no real number squared equals −1. Sometimes a quadratic equation has a root of multiplicity 2, such as: ( x + 1 ) 2 = 0.
FEV1/FVC ratio Disease states FEV1/FVC_ratio > Disease states According to the European Respiratory Society (ERS) criteria, it is FEV1% predicted that defines when a patient has COPD—that is, when the patient's FEV1% is less than 88% of the predicted value for men, or less than 89% for women.In restrictive lung disease, the FEV1 and FVC are equally reduced due to fibrosis or other lung pathology (not obstructive pathology). Thus, the FEV1/FVC ratio should be approximately normal, or even increased due to a decrease in magnitude of FVC as compared to FEV1 (because of the decreased compliance associated with the presence of fibrosis in some pathological conditions). == References ==
Multi-way tree Recursive definition Multi-way_tree > Recursive definition In later literature, the 1+2b variant is usually introduced by the following definition: A rose tree is either a leaf containing a value, or a node that can have an arbitrary list of subtrees.The most common definition used in functional programming (particularly in Haskell) combines 3+2b: An element of Rose α consists of a labelled node together with a list of subtrees. That is, a rose tree is a pairing entity (type 3) whose branching entity is a sequence (thus of type 2b) of rose trees.
Algorithm function Jump to subroutine Local_variables,_recursion_and_reentrancy > Jump to subroutine Another advance was the jump to subroutine instruction, which combined the saving of the return address with the calling jump, thereby minimizing overhead significantly. In the IBM System/360, for example, the branch instructions BAL or BALR, designed for procedure calling, would save the return address in a processor register specified in the instruction, by convention register 14. To return, the subroutine had only to execute an indirect branch instruction (BR) through that register. If the subroutine needed that register for some other purpose (such as calling another subroutine), it would save the register's contents to a private memory location or a register stack.
Czesław Olech Education and career Czesław_Olech > Education and career He cooperated with Solomon Lefschetz, Sergey Nikolsky, Philip Hartman and Roberto Conti, the most distinguished mathematicians involved in the theory of differential equations. Lefschetz highly valued Ważewski's school, and especially the retract method, which Olech applied by developing, among other things, control theory. He supervised nine doctoral dissertations, and reviewed a number of theses and dissertations.
Euclidean random matrix History Euclidean_random_matrix > History Euclidean random matrices were first introduced in 1999. They studied a special case of functions f that depend only on the distances between the pairs of points: f(r, r′) = f(r - r′) and imposed an additional condition on the diagonal elements Aii, Aij = f(ri - rj) - u δijΣkf(ri - rk),motivated by the physical context in which they studied the matrix. A Euclidean distance matrix is a particular example of Euclidean random matrix with either f(ri - rj) = \|ri - rj\|2 or f(ri - rj) = \|ri - rj\|.For example, in many biological networks, the strength of interaction between two nodes depends on the physical proximity of those nodes. Spatial interactions between nodes can be modelled as a Euclidean random matrix, if nodes are placed randomly in space.
Identity (mathematics) Change of base Mathematical_identity > Common identities > Logarithmic identities > Change of base The logarithm logb(x) can be computed from the logarithms of x and b with respect to an arbitrary base k using the following formula: log b ⁡ ( x ) = log k ⁡ ( x ) log k ⁡ ( b ) . {\displaystyle \log _{b}(x)={\frac {\log _{k}(x)}{\log _{k}(b)}}.} Typical scientific calculators calculate the logarithms to bases 10 and e. Logarithms with respect to any base b can be determined using either of these two logarithms by the previous formula: log b ⁡ ( x ) = log 10 ⁡ ( x ) log 10 ⁡ ( b ) = log e ⁡ ( x ) log e ⁡ ( b ) . {\displaystyle \log _{b}(x)={\frac {\log _{10}(x)}{\log _{10}(b)}}={\frac {\log _{e}(x)}{\log _{e}(b)}}.} Given a number x and its logarithm logb(x) to an unknown base b, the base is given by: b = x 1 log b ⁡ ( x ) . {\displaystyle b=x^{\frac {1}{\log _{b}(x)}}.}
Drift racing Drivetrain Drift_racing > Drift tuning > Drivetrain ran in his 2016 Mustang) with more open-ratio gears, this limits the number of shifts the driver has to do during their run. These may be coarser dog engagement straight cut gears instead of synchronised helical gears, for durability and faster shifting at the expense of noise and refinement. Wealthier drifters may use sequential gearboxes to make gear selection easier and faster, while sequential shift lever adapters can be used to make shifts easier without increasing shift time.
Ruling grade Summary Ruling_gradient It is cheaper than running a too-powerful locomotive over the entire track mileage just in order to make the grade, especially when multiple trains run over the line each day (to help justify the fixed daily cost of the helper operation). In the 1953 edition of Railway Engineering William H. Hay says "The ruling grade may be defined as the maximum gradient over which a tonnage train can be hauled with one locomotive....The ruling grade does not necessarily have the maximum gradient on the division. Momentum grades, pusher grades, or those that must regularly be doubled by tonnage trains may be heavier." This means the "ruling grade" may change if the management chooses to operate the railroad differently.
Diffusion Summary Diffusion_rate A change in concentration over a distance is called a concentration gradient, a change in pressure over a distance is called a pressure gradient, and a change in temperature over a distance is called a temperature gradient. The word diffusion derives from the Latin word, diffundere, which means "to spread out".
Teleology in biology Adaptation Teleology_in_biology > Context > Adaptation A trait which persists in a population is often assumed by biologists to have been selected for in the course of evolution, raising the question of how the trait achieves this. Biologists call any such mechanism the function of the trait, using phrases like "A function of stotting by antelopes is to communicate to predators that they have been detected", or "The primate hand is designed (by natural selection) for grasping. "An adaptation is an observable structure or other feature of an organism (for example, an enzyme) generated by natural selection to serve its current function. A biologist might propose the hypothesis that feathers are adaptations for bird flight.
Immune checkpoint inhibitor Anti-GD2 antibodies PD-1_inhibitor > Research > Anti-GD2 antibodies Carbohydrate antigens on the surface of cells can be used as targets for immunotherapy. GD2 is a ganglioside found on the surface of many types of cancer cell including neuroblastoma, retinoblastoma, melanoma, small cell lung cancer, brain tumors, osteosarcoma, rhabdomyosarcoma, Ewing's sarcoma, liposarcoma, fibrosarcoma, leiomyosarcoma and other soft tissue sarcomas. It is not usually expressed on the surface of normal tissues, making it a good target for immunotherapy. As of 2014, clinical trials were underway.
Rep-tile Rep-tiles and symmetry Rep-tile > Rep-tiles and symmetry Some rep-tiles, like the square and equilateral triangle, are symmetrical and remain identical when reflected in a mirror. Others, like the sphinx, are asymmetrical and exist in two distinct forms related by mirror-reflection. Dissection of the sphinx and some other asymmetric rep-tiles requires use of both the original shape and its mirror-image.
Phosphoprotein phosphatase Physiological relevance Phosphoprotein_phosphatase > Physiological relevance The enzyme then acts to dephosphorylate other enzymes, such as phosphorylase kinase, glycogen phosphorylase, and glycogen synthase. This leads to phosphorylase kinase and glycogen phosphorylase's becoming inactive, while glycogen synthase is activated. As a result, glycogen synthesis is increased and glycogenolysis is decreased, and the net effect is for energy to enter and be stored inside the cell.
Hormone replacement therapy (male-to-female) GnRH modulators Hormone_replacement_therapy_(male-to-female) > Medications > Antiandrogens > GnRH modulators GnRH modulators are antigonadotropins and hence functional antiandrogens. In both males and females, gonadotropin-releasing hormone (GnRH) is produced in the hypothalamus and induces the secretion of the gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland. The gonadotropins signal the gonads to make sex hormones such as testosterone and estradiol. GnRH modulators bind to and inhibit the GnRH receptor, thereby preventing gonadotropin release.
Algorithm characterization 1972 Stone's characterization Algorithm_characterizations > 1972 Stone's characterization 9). Immediately thereafter he goes on say that a “computation of a Turing machine is described by stating: "1. The tape alphabet "2.
Thin-skinned deformation Summary Thin-skinned_deformation Thin-skinned deformation is a style of deformation in plate tectonics at a convergent boundary which occurs with shallow thrust faults that only involves cover rocks (typically sedimentary rocks), and not deeper basement rocks.The thin-skinned style of deformation is typical of many fold and thrust belts developed in the foreland of a collisional zone or back arc of a continental volcanic arc. This is particularly the case where a good basal decollement exists, usually in a weaker layer like a shale, evaporite, or a zone of high pore fluid pressure. This was first described in Rocky Mountains of the United States, as part of the Sevier Orogeny.In the rock record, this will increase the influence of more surficial rocks, which usually includes sedimentary rocks. Typically, repeated sections of the same rock are seen over and over as thrust faults, coming up from the decollement, stack the same layer on top of itself. The sediments that are created by this type of deformation are typically lithic sandstones.
Photofission Photodisintegration Photofission > Photodisintegration Photodisintegration (also called phototransmutation) is a similar but different physical process, in which an extremely high energy gamma ray interacts with an atomic nucleus and causes it to enter an excited state, which immediately decays by emitting a subatomic particle. == References ==
GNU Radio Plotting and Displays GNU_Radio > Software > Plotting and Displays GNU Radio provides many common plotting and data visualization data sinks, including FFT displays, symbol constellation diagrams, and scope displays. These are commonly used both for debugging radio applications and as the user-interface to a final application.
Blending function Summary Basis_function In mathematics, a basis function is an element of a particular basis for a function space. Every function in the function space can be represented as a linear combination of basis functions, just as every vector in a vector space can be represented as a linear combination of basis vectors. In numerical analysis and approximation theory, basis functions are also called blending functions, because of their use in interpolation: In this application, a mixture of the basis functions provides an interpolating function (with the "blend" depending on the evaluation of the basis functions at the data points).
Carbon-carbon bonds Summary C-C_bond A double bond is formed with an sp2-hybridized orbital and a p-orbital that is not involved in the hybridization. A triple bond is formed with an sp-hybridized orbital and two p-orbitals from each atom. The use of the p-orbitals forms a pi bond.
Outline of combinatorics Data structure concepts Outline_of_combinatorics > Data structure concepts Data structure Data type Abstract data type Algebraic data type Composite type Array Associative array Deque List Linked list Queue Priority queue Skip list Stack Tree data structure Automatic garbage collection
Introduction to viruses Vaccines Introduction_to_viruses > Viruses and diseases > Prevention and treatment of viral disease > Vaccines Live vaccines contain weakened forms of the virus, but these vaccines can be dangerous when given to people with weak immunity. In these people, the weakened virus can cause the original disease. Biotechnology and genetic engineering techniques are used to produce "designer" vaccines that only have the capsid proteins of the virus. Hepatitis B vaccine is an example of this type of vaccine. These vaccines are safer because they can never cause the disease.
EB-eye What can the user search for? EB-eye > The EB-eye – the EBI search engine for biological data > Access to the EB-eye > What can the user search for? Many resources at EBI are indexed within the search engine, but some are not. The EB-eye can search only the information that gets indexed. This implies that other search engines operating on biological data might yield different results. As a rule of thumb, the EB-eye search engine index identifiers, names, descriptions, keywords and cross-references.
Linear approximation table Properties Switching_function > Analysis > Properties Symmetric: the value does not depend on the order of its arguments. Read-once: Can be expressed with conjunction, disjunction, and negation with a single instance of each variable. Balanced: if its truth table contains an equal number of zeros and ones. The Hamming weight of the function is the number of ones in the truth table. Bent: its derivatives are all balanced (the autocorrelation spectrum is zero) Correlation immune to mth order: if the output is uncorrelated with all (linear) combinations of at most m arguments Evasive: if evaluation of the function always requires the value of all arguments A Boolean function is a Sheffer function if it can be used to create (by composition) any arbitrary Boolean function (see functional completeness) The algebraic degree of a function is the order of the highest order monomial in its algebraic normal formCircuit complexity attempts to classify Boolean functions with respect to the size or depth of circuits that can compute them.
Semidefinite programming Example 3 (Goemans–Williamson max cut approximation algorithm) Semidefinite_program > Examples > Example 3 (Goemans–Williamson max cut approximation algorithm) Assuming the unique games conjecture, it can be shown that this approximation ratio is essentially optimal. Since the original paper of Goemans and Williamson, SDPs have been applied to develop numerous approximation algorithms. Recently, Prasad Raghavendra has developed a general framework for constraint satisfaction problems based on the unique games conjecture.
Strain theory (sociology) Sources and further reading Strain_theory_(sociology) > Sources and further reading Archives of Suicide Research. 12 (1): 67–73. doi:10.1080/13811110701800962.
Procedural knowledge Activation Procedural_knowledge > Activation The same sound pattern can be interpreted differently depending on where it occurs in a sentence, for example, there and their. Such contextual dependence is only possible with functionally overarching states of the sort implied by hierarchical plans. The initiation time of a movement sequence and the inter-response times of the sequence elements can increase with its length.
Rock-fill dam Gravity dams Dammed_water > Types > By structure > Gravity dams In a gravity dam, the force that holds the dam in place against the push from the water is Earth's gravity pulling down on the mass of the dam. The water presses laterally (downstream) on the dam, tending to overturn the dam by rotating about its toe (a point at the bottom downstream side of the dam). The dam's weight counteracts that force, tending to rotate the dam the other way about its toe. The designer ensures that the dam is heavy enough that the dam's weight wins that contest.
Asystole Summary Asystole Asystolic patients (as opposed to those with a "shockable rhythm" such as coarse or fine ventricular fibrillation, or unstable ventricular tachycardia that is not producing a pulse, which can potentially be treated with defibrillation) usually present with a very poor prognosis. Asystole is found initially in only about 28% of cardiac arrest cases in hospitalized patients, but only 15% of these survive, even with the benefit of an intensive care unit, with the rate being lower (6%) for those already prescribed drugs for high blood pressure.Asystole is treated by cardiopulmonary resuscitation (CPR) combined with an intravenous vasopressor such as epinephrine (a.k.a. adrenaline).
Complex adaptive system Overview Complex_adaptive_system > Overview Human social group-based endeavors, such as political parties, communities, geopolitical organizations, war, and terrorist networks are also considered CAS. The internet and cyberspace—composed, collaborated, and managed by a complex mix of human–computer interactions, is also regarded as a complex adaptive system.
Thulium(III) hydroxide Summary Thulium(III)_hydroxide Thulium(III) hydroxide is an inorganic compound with the chemical formula Tm(OH)3.
Matrix decoder Summary Matrix_decoder Matrix decoding is an audio technology where a small number of discrete audio channels (e.g., 2) are decoded into a larger number of channels on play back (e.g., 5). The channels are generally, but not always, arranged for transmission or recording by an encoder, and decoded for playback by a decoder. The function is to allow multichannel audio, such as quadraphonic sound or surround sound to be encoded in a stereo signal, and thus played back as stereo on stereo equipment, and as surround on surround equipment – this is "compatible" multichannel audio.
Glossary of genetics (M–Z) P Glossary_of_genetics_(M–Z) > P prophase The first stage of cell division in both mitosis and meiosis, occurring after interphase and before prometaphase, during which the DNA of the chromosomes is condensed into chromatin, the nucleolus disintegrates, centrosomes move to opposite ends of the cell, and the mitotic spindle forms. protein A polymeric macromolecule composed of one or more long chains of amino acids linked by peptide bonds. Proteins are the three-dimensional structures created when these chains fold into specific higher-order arrangements following translation, and it is this folded structure which determines a protein's chemical activity and hence its biological function.
Lauri Vaska Research Lauri_Vaska > Research Vaska published ca. eighty journal articles on the coordination chemistry of transition metals, homogeneous catalysis, and both organometallic and bioinorganic chemistry. His years at Mellon were especially productive.
Shock (circulatory) Compensatory Shock_(circulatory) > Pathophysiology > Compensatory These hormones cause the vasoconstriction of the kidneys, gastrointestinal tract, and other organs to divert blood to the heart, lungs and brain. The lack of blood to the renal system causes the characteristic low urine production. However the effects of the renin–angiotensin axis take time and are of little importance to the immediate homeostatic mediation of shock.
Mesoamerican nephropathy History Mesoamerican_nephropathy > History In April 2013, a high-level meeting with regional health ministries, nongovernmental organizations, aid agencies, clinical specialists and researchers was held in San Salvador city, El Salvador, leading the Panamerican Health Organization (PAHO) to finally declare CKDu "a pressing and extremely serious health problem in the region". The Declaration described CKD as having "catastrophic effects associated with toxic-environmental and occupational factors, dehydration and behaviors harmful to renal health".
Glossary of engineering: A–L C Glossary_of_engineering:_A–L > C Control engineeringControl engineering or control systems engineering is an engineering discipline that applies automatic control theory to design systems with desired behaviors in control environments. The discipline of controls overlaps and is usually taught along with electrical engineering at many institutions around the world.
Ranked alphabet Summary Ranked_alphabet Higher arities lead to proper trees. For instance, in the term f ( a , g ( a ) , f ( a , b , c ) ) {\displaystyle f(a,g(a),f(a,b,c))} ,a,b,c are constants, g is unary, and f is ternary. Contrariwise, f ( a , f ( a ) ) {\displaystyle f(a,f(a))} cannot be a valid term, as the symbol f appears once as binary, and once as unary, which is illicit, as Arity must be a function.
Protease-activated receptor Activation Protease-activated_receptor > Activation These findings suggest that TFF3 activates intestinal epithelial cells through G-protein-coupled PAR-2, and could actively participate in the immune system of breastfed babies inducing the production of peptides related to innate defense, such as defensins and cytokines.PARs are activated by the action of serine proteases such as thrombin (acts on PARs 1, 3 and 4) and trypsin (PAR 2). These enzymes cleave the N-terminus of the receptor, which in turn acts as a tethered ligand. In the cleaved state, part of the receptor itself acts as the agonist, causing a physiological response. Most of the PAR family act through the actions of G-proteins i (cAMP inhibitory), 12/13 (Rho and Ras activation) and q (calcium signalling) to cause cellular actions.
Kernel preemption Summary Kernel_preemption In computer operating system design, kernel preemption is a property possessed by some kernels (the cores of operating systems), in which the CPU can be interrupted in the middle of executing kernel code and assigned other tasks (from which it later returns to finish its kernel tasks).
Cato Networks Products Cato_Networks > Products Cato Networks develops a Secure Access Service Edge (SASE) platform, which combines SD-WAN, managed security service and global backbone services into a cloud-based service offering. Its products are designed to help IT staff manage network security for distributed workforces accessing resources across the wide area networks (WANs), cloud and Internet that connects them. The company's Cato SASE Cloud platform supports more than 73 points of presence in over 150 countries. The company's managed detection and response (MDR) platform combines machine learning and artificial intelligence (AI) models to process network traffic data and identify threats to its customers. The company also offers cloud access security broker (CASB) capabilities to protect cloud applications.
History of molecular biology The encounter between biochemistry and genetics History_of_molecular_biology > The encounter between biochemistry and genetics One noteworthy study used amber mutants defective in the gene encoding the major head protein of bacteriophage T4. This experiment provided strong evidence for the widely held, but prior to 1964 still unproven, "sequence hypothesis" that the amino acid sequence of a protein is specified by the nucleotide sequence of the gene determining the protein. Thus, this study demonstrated the co-linearity of the gene with its encoded protein.
Task allocation and partitioning of social insects Network representation of information flow and task allocation Task_allocation_and_partitioning_in_social_insects > Network representation of information flow and task allocation Traditionally, workers are the nodes of the graph, but Fewell prefers to make the tasks the nodes, with workers as the links. O'Donnell has coined the term "worker connectivity" to stand for "communicative interactions that link a colony's workers in a social network and affect task performance". He has pointed out that connectivity provides three adaptive advantages compared to individual direct perception of needs: It increases both the physical and temporal reach of information.
Lung cancer staging with endoscopic ultrasound Summary Lung_cancer_staging_with_endoscopic_ultrasound Invasive techniques provide additional information because tissue samples can be seen microscopically to confirm presence of cancer cells (as opposed to enlargement of tissues due to other causes such as infection) and to determine the type of lung cancer and its grade. Staging may also be categorized as either clinical or as pathological/surgical staging. Clinical staging is performed prior to definitive surgery. It is based on the results of imaging studies (such as CT scans ) and biopsy results (i.e. clinical staging does include the results of biopsy, an "invasive technique.") Pathological staging is also called surgical staging and reflects not only the results of non-surgical biopsy, but is evaluated either intra- or post-operatively and is based on the combined results of surgical and clinical findings, including surgical sampling of thoracic lymph nodes.
Machine learning in video games Reinforcement learning Machine_learning_in_video_games > Overview of relevant machine learning techniques > Reinforcement learning Reinforcement learning is the process of training an agent using rewards and/or punishments. The way an agent is rewarded or punished depends heavily on the problem; such as giving an agent a positive reward for winning a game or a negative one for losing. Reinforcement learning is used heavily in the field of machine learning and can be seen in methods such as Q-learning, policy search, Deep Q-networks and others. It has seen strong performance in both the field of games and robotics.
Flexibility method Advantages and disadvantages Flexibility_method > Advantages and disadvantages However, recent advances in numerical computing have shown a comeback of the force method, especially in the case of nonlinear systems. New frameworks have been developed that allow "exact" formulations irrespectively of the type or nature of the system nonlinearities. The main advantages of the flexibility method is that the result error is independent of the discretization of the model and that it is indeed a very fast method. For instance, the elastic-plastic solution of a continuous beam using the force method requires only 4 beam elements whereas a commercial "stiffness based" FEM code requires 500 elements in order to give results with the same accuracy. To conclude, one can say that in the case where the solution of the problem requires recursive evaluations of the force field like in the case of structural optimization or system identification, the efficiency of the flexibility method is indisputable.
Molar heat capacity Specific heat of solid elements Molar_heat_capacity > Physical basis > Specific heat of solids > Specific heat of solid elements The molar volume of solid elements is very roughly constant, and (even more reliably) so also is the molar heat capacity for most solid substances. These two factors determine the volumetric heat capacity, which as a bulk property may be striking in consistency. For example, the element uranium is a metal that has a density almost 36 times that of the metal lithium, but uranium's specific heat capacity on a volumetric basis (i.e. per given volume of metal) is only 18% larger than lithium's.
Domain name registry Summary Domain_name_registration It may also fulfill the function of a domain name registrar, or may delegate that function to other entities.Domain names are managed under a hierarchy headed by the Internet Assigned Numbers Authority (IANA), which manages the top of the DNS tree by administrating the data in the root nameservers. IANA also operates the int registry for intergovernmental organizations, the arpa zone for protocol administration purposes, and other critical zones such as root-servers.net. IANA delegates all other domain name authority to other domain name registries and a full list is available on their web site. Country code top-level domains (ccTLD) are delegated by IANA to national registries such as DENIC in Germany and Nominet in the United Kingdom.
Pooling (neural networks) Local connectivity Max_pooling > Building blocks > Convolutional layer > Local connectivity When dealing with high-dimensional inputs such as images, it is impractical to connect neurons to all neurons in the previous volume because such a network architecture does not take the spatial structure of the data into account. Convolutional networks exploit spatially local correlation by enforcing a sparse local connectivity pattern between neurons of adjacent layers: each neuron is connected to only a small region of the input volume. The extent of this connectivity is a hyperparameter called the receptive field of the neuron. The connections are local in space (along width and height), but always extend along the entire depth of the input volume. Such an architecture ensures that the learned (British English: learnt) filters produce the strongest response to a spatially local input pattern.
Gait (human) Locomotor centers Gait_(human) > Control of gait by the nervous system > Locomotor centers Deep brain stimulation of the MLR in individuals with Parkinson's has also led to improvements in gait and posture. Sub thalamic Locomotor Region (SLR)- The SLR is part of hypothalamus. It activates the spinal locomotor networks both directly and indirectly via the MLR.
Redox buffer Sedimentary rocks Mineral_redox_buffer > Minerals, rock types, and characteristic buffers > Sedimentary rocks Oxidizing conditions are common in some environments of deposition and diagenesis of sedimentary rocks. The fugacity of oxygen at the MH buffer (magnetite-hematite) is only about 10−70 at 25 °C, but it is about 0.2 atmospheres in the Earth's atmosphere, so some sedimentary environments are far more oxidizing than those in magmas. Other sedimentary environments, such as the environments for formation of black shale, are relatively reducing.
Conceptual model Concept models and conceptual models Conceptual_model > Overview > Concept models and conceptual models The value of a conceptual model is usually directly proportional to how well it corresponds to a past, present, future, actual or potential state of affairs. A concept model (a model of a concept) is quite different because in order to be a good model it need not have this real world correspondence. In artificial intelligence, conceptual models and conceptual graphs are used for building expert systems and knowledge-based systems; here the analysts are concerned to represent expert opinion on what is true not their own ideas on what is true.
Ideal voltage source Ideal voltage sources Voltage_source > Ideal voltage sources An ideal voltage source is a two-terminal device that maintains a fixed voltage drop across its terminals. It is often used as a mathematical abstraction that simplifies the analysis of real electric circuits. If the voltage across an ideal voltage source can be specified independently of any other variable in a circuit, it is called an independent voltage source. Conversely, if the voltage across an ideal voltage source is determined by some other voltage or current in a circuit, it is called a dependent or controlled voltage source.
Multipoint relay Benefits Multipoint_relay > Benefits Default and network routes can be injected into the system by Host and Network Association (HNA) messages allowing for connection to the internet or other networks within the OLSR MANET cloud. Network routes are something reactive protocols do not currently execute well. Timeout values and validity information is contained within the messages conveying information allowing for differing timer values to be used at differing nodes.
Contravariant vector Introduction Covariant_vector > Introduction For a vector to represent a geometric object, it must be possible to describe how it looks in any other coordinate system. That is to say, the components of the vectors will transform in a certain way in passing from one coordinate system to another. A vector, which is an example of a contravariant tensor, has components that transform inversely to the transformation of the reference axes, (with example transformations including rotation and dilation).
Linear logic programming Summary Linear_logic_programming Even facts have a procedural interpretation. For example, the clause: human(socrates).can be used both as a procedure to show that socrates is human, and as a procedure to find an X that is human by "assigning" socrates to X. The declarative reading of logic programs can be used by a programmer to verify their correctness. Moreover, logic-based program transformation techniques can also be used to transform logic programs into logically equivalent programs that are more efficient. In addition, the programmer can use knowledge of the problem-solving behaviour of the implementation of the language, to write programs that exploit that behaviour for the sake of greater efficiency.
Data field Summary Data_field In object-oriented programming, a field (also called data member or member variable) is a particular piece of data encapsulated within a class or object. In the case of a regular field (also called instance variable), for each instance of the object there is an instance variable: for example, an Employee class has a Name field and there is one distinct name per employee. A static field (also called class variable) is one variable, which is shared by all instances. Fields are abstracted by properties, which allow them to be read and written as if they were fields, but these can be translated to getter and setter method calls.
Water fight Summary Water_fight A water fight is a type of mock combat using various water-dispensing devices to soak opponents. Everything from buckets to balloons to water guns and even cupped hands cradling water can be applied in a water fight. There are many different levels of game play used by those engaging in water fights, from quick, casual fights to long, objective-oriented-style water warfare campaigns, and tournament-style games. In most but not all cases, the common objective is to soak (spray with water) one's opponents while trying to remain dry. Water fights are most common in hot summer weather in order to cool off.
Endothelial cells Clinical significance Endothelial_cell > Clinical significance In contrast, inflammatory stimuli also activate NF-κB-induced expression of the deubiquitinase A20 (TNFAIP3), which has been shown to intrinsically repair the endothelial barrier.One of the main mechanisms of endothelial dysfunction is the diminishing of nitric oxide, often due to high levels of asymmetric dimethylarginine, which interfere with the normal L-arginine-stimulated nitric oxide synthesis and so leads to hypertension. The most prevailing mechanism of endothelial dysfunction is an increase in reactive oxygen species, which can impair nitric oxide production and activity via several mechanisms. The signalling protein ERK5 is essential for maintaining normal endothelial cell function.
Pancake sorting History Pancake_sorting > History The pancake sorting problem was first posed by Jacob E. Goodman, writing under the pseudonym "Harry Dweighter" ("harried waiter").Although seen more often as an educational device, pancake sorting also appears in applications in parallel processor networks, in which it can provide an effective routing algorithm between processors.The problem is notable as the topic of the only well-known mathematics paper by Microsoft founder Bill Gates (as William Gates), entitled "Bounds for Sorting by Prefix Reversal" and co-authored with Christos Papadimitriou. Published in 1979, it describes an efficient algorithm for pancake sorting. In addition, the most notable paper published by Futurama co-creator David X. Cohen (as David S. Cohen), co-authored with Manuel Blum, concerned the burnt pancake problem.The connected problems of signed sorting by reversals and sorting by reversals were also studied more recently. Whereas efficient exact algorithms have been found for the signed sorting by reversals, the problem of sorting by reversals has been proven to be hard even to approximate to within certain constant factor, and also proven to be approximable in polynomial time to within the approximation factor 1.375.
Morning star (candlestick pattern) Interpretation Morning_star_(candlestick_pattern) > Interpretation When found in a downtrend, this pattern can be an indication that a reversal in the price trend is going to take place. What the pattern represents from a supply and demand point of view is a lot of selling in the period of the first black candle. Then, a period of lower trading with a reduced range, which indicates indecision in the market, forms the second candle. This is followed by a large white candle, which represents buyers taking control of the market.
Java byte code Generation Java_bytecode > Generation The most common language targeting Java virtual machine by producing Java bytecode is Java. Originally only one compiler existed, the javac compiler from Sun Microsystems, which compiles Java source code to Java bytecode; but because all the specifications for Java bytecode are now available, other parties have supplied compilers that produce Java bytecode. Examples of other compilers include: Eclipse compiler for Java (ECJ) Jikes, compiles from Java to Java bytecode (developed by IBM, implemented in C++) Espresso, compiles from Java to Java bytecode (Java 1.0 only) GNU Compiler for Java (GCJ), compiles from Java to Java bytecode; it can also compile to native machine code and was part of the GNU Compiler Collection (GCC) up until version 6.Some projects provide Java assemblers to enable writing Java bytecode by hand. Assembly code may be also generated by machine, for example by a compiler targeting a Java virtual machine.
Thiomer Efflux pump inhibition Thiomer > Properties and applications > Efflux pump inhibition Two of these transmembrane domains – namely 2 and 11 – exhibit on position 137 and 956, respectively, a cysteine subunit. Thiomers seem to enter in the channel of P-gp and likely form subsequently one or two disulfide bonds with one or both cysteine subunits located within the channel. Due to this covalent interaction the allosteric change of the transporter being essential to move drugs outside of the cell might be blocked.
Nephrotic syndrome Kidney damage Nephrotic_syndrome > Treatment > Kidney damage The treatment of kidney damage may reverse or delay the progression of the disease. Kidney damage is treated by prescribing drugs: Corticosteroids: the result is a decrease in proteinuria and the risk of infection as well as a resolution of the edema. Prednisone is usually prescribed at a dose of 60 mg/m2 of body surface area/day in a first treatment for 4–8 weeks. After this period the dose is reduced to 40 mg/m2 for a further 4 weeks.
Shockley–Queisser limit Thermophotovoltaic downconversion Shockley–Queisser_limit > Exceeding the limit > Thermophotovoltaic downconversion Thermophotovoltaic cells are similar to phosphorescent systems, but use a plate to act as the downconvertor. Solar energy falling on the plate, typically black-painted metal, is re-emitted as lower-energy IR, which can then be captured in an IR cell. This relies on a practical IR cell being available, but the theoretical conversion efficiency can be calculated. For a converter with a bandgap of 0.92 eV, efficiency is limited to 54% with a single-junction cell, and 85% for concentrated light shining on ideal components with no optical losses and only radiative recombination.
Self-regulating heater Adjustable temperature Positive_temperature_coefficient_heating_element > Properties > Adjustable temperature If being able to adjust the temperature is more important than holding a fixed temperature, then a PTC material whose resistance changes smoothly with temperature can be used. The temperature such a material tends to hold can be adjusted by changing the voltage applied.
Psychiatric medication Antidepressants Psychiatric_medication > Types > Antidepressants Antidepressants are drugs used to treat clinical depression, and they are also often used for anxiety and other disorders. Most antidepressants will hinder the breakdown of serotonin, norepinephrine, and/or dopamine. A commonly used class of antidepressants are called selective serotonin reuptake inhibitors (SSRIs), which act on serotonin transporters in the brain to increase levels of serotonin in the synaptic cleft. Another is the serotonin-norepinephrine reuptake inhibitors (SNRIs), which increase both serotonin and norepinephrine.
D electron count Limitation D_electron_count > Limitation Counting d electrons is a formalism. Often it is difficult or impossible to assign electrons and charge to the metal center or a ligand. For a high-oxidation-state metal center with a +4 charge or greater it is understood that the true charge separation is much smaller. But referring to the formal oxidation state and d electron count can still be useful when trying to understand the chemistry.
OFML Motivations OFML > Motivations OFML is the result of a series of requirements that could generally not be met with past solutions: The new requirements in the area of planning and visualization of furniture cannot be met alone by CAD-based systems. The main problems of CAD-based solutions are the enormous data size, the poor parameterizability and configurability, insufficient product logic, insufficient interactivity and complicated operation. A platform-independent and software manufacturer-independent data format which allows an unlimited number of software manufacturers to offer systems and solutions so that monopolizing conditions can be avoided or eliminated. The new data format also allows for the implementation of a series of applications that are compatible with respect to the data in spite of different orientation. In this way it is possible to achieve compatibility and, therefore, technological uniformity between manufacturer, trade, and end user systems.
International System of Units Realisation of units SI_Units > Realisation of units : 168–169 The published mise en pratique is not the only way in which a base unit can be determined: the SI Brochure states that "any method consistent with the laws of physics could be used to realise any SI unit. ": 111 Various consultative committees of the CIPM decided in 2016 that more than one mise en pratique would be developed for determining the value of each unit.
Theory of programming languages Formal semantics Programming_language_theory > Sub-disciplines and related fields > Formal semantics Formal semantics is the formal specification of the behaviour of computer programs and programming languages. Three common approaches to describe the semantics or "meaning" of a computer program are denotational semantics, operational semantics and axiomatic semantics.
Current carrying capacity Summary Current_carrying_capacity All common electrical conductors have some resistance to the flow of electricity. Electric current flowing through them causes voltage drop and power dissipation, which heats conductors.

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