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Garbage can model Specialized access Garbage_can_model > Model constraints > Access Structure > Specialized access Specialized access happens when only special problems and solutions can gain entry to certain meetings. Specific specialists have access to specific choices that fit their expertise. Each problem has access to only one choice and each choice is accessible to only two problems. Hence, choices specialize in the types of problems that can be connected to them. An example could be computer specialists in a technology committee addressing technical issues. |
Flood fill Moving the recursion into a data structure Flood_fill > Stack-based recursive implementation (four-way) > Moving the recursion into a data structure Moving the recursion into a data structure (either a stack or a queue) prevents a stack overflow. It is similar to the simple recursive solution, except that instead of making recursive calls, it pushes the nodes onto a stack or queue for consumption, with the choice of data structure affecting the proliferation pattern: Flood-fill (node): 1. Set Q to the empty queue or stack. 2. |
Iridium satellite constellation In-orbit spares Iridium_95 > Original Iridium constellation > In-orbit spares A move can take several weeks and consumes fuel which will shorten the satellite's expected service life. Significant orbital inclination changes are normally very fuel-intensive, but orbital perturbation analysis aids the process. The Earth's equatorial bulge causes the orbital right ascension of the ascending node (RAAN) to precess at a rate that depends mainly on the period and inclination. |
Interoperability Interoperability and open standards Syntactic_interoperability > Interoperability and open standards Interoperability implies exchanges between a range of products, or similar products from several different vendors, or even between past and future revisions of the same product. Interoperability may be developed post-facto, as a special measure between two products, while excluding the rest, by using open standards. When a vendor is forced to adapt its system to a dominant system that is not based on Open standards, it is compatibility, not interoperability. |
Solar lantern Working principles Solar_lamp > Working principles LED lights are used due to their high luminous efficiency and long life. Under the control of a DC charge controller, non-contact control automatically turns on the light at dark and switches off at daytime. It sometimes also combines with time controllers to set certain time for it to automatically switch light on and off.As shown in Figure 3, the chip includes microchip(R), B-, B+, S- and S+. S+ and S- are both connected to solar panels with wire, one of which has plus charge and the other minus charge. B- and B+ are attached to two batteries in this case. The light will be shown through the LED light when all of these are connected. |
Primary producer Photosynthesis Autotrophic_nutrition > Photosynthesis During photosynthesis, primary producers take energy from the sun and convert it into energy, sugar, and oxygen. Primary producers also need the energy to convert this same energy elsewhere, so they get it from nutrients. One type of nutrient is nitrogen. |
Nervous system network models Artificial neural networks Nervous_system_network_models > Nervous system models > Artificial neural networks As mentioned in Section 2.4, development of artificial neural network (ANN), or neural network as it is now called, started as simulation of biological neuron network and ended up using artificial neurons. Major development work has gone into industrial applications with learning process. Complex problems were addressed by simplifying the assumptions. Algorithms were developed to achieve a neurological related performance, such as learning from experience. |
History of geometry Plato History_of_geometry > Greek geometry > Classical Greek geometry > Plato Mathematicians thus accepted his belief that geometry should use no tools but compass and straightedge – never measuring instruments such as a marked ruler or a protractor, because these were a workman's tools, not worthy of a scholar. This dictum led to a deep study of possible compass and straightedge constructions, and three classic construction problems: how to use these tools to trisect an angle, to construct a cube twice the volume of a given cube, and to construct a square equal in area to a given circle. The proofs of the impossibility of these constructions, finally achieved in the 19th century, led to important principles regarding the deep structure of the real number system. Aristotle (384-322 BC), Plato's greatest pupil, wrote a treatise on methods of reasoning used in deductive proofs (see Logic) which was not substantially improved upon until the 19th century. |
VLSI circuit Background Very-large-scale_integration > History > Background The history of the transistor dates to the 1920s when several inventors attempted devices that were intended to control current in solid-state diodes and convert them into triodes. Success came after World War II, when the use of silicon and germanium crystals as radar detectors led to improvements in fabrication and theory. Scientists who had worked on radar returned to solid-state device development. With the invention of the first transistor at Bell Labs in 1947, the field of electronics shifted from vacuum tubes to solid-state devices. |
Newton's theorem of revolving orbits Historical context Newton's_theorem_of_revolving_orbits > Historical context However, this conclusion holds only when two bodies are present (the two-body problem); the motion of three bodies or more acting under their mutual gravitation (the n-body problem) remained unsolved for centuries after Newton, although solutions to a few special cases were discovered. Newton proposed that the orbits of planets about the Sun are largely elliptical because the Sun's gravitation is dominant; to first approximation, the presence of the other planets can be ignored. By analogy, the elliptical orbit of the Moon about the Earth was dominated by the Earth's gravity; to first approximation, the Sun's gravity and those of other bodies of the Solar System can be neglected. |
Quantity of dimension one Physics and engineering Dimensionless_parameter > List > Physics and engineering It represents the ratio of the convective mass transfer to the rate of diffusive mass transport. Schmidt number – defined as the ratio of momentum diffusivity (kinematic viscosity) and mass diffusivity, and is used to characterize fluid flows in which there are simultaneous momentum and mass diffusion convection processes. Reynolds number is commonly used in fluid mechanics to characterize flow, incorporating both properties of the fluid and the flow. |
Poly(A) tail In prokaryotes and organelles Poly(A)_tail > In prokaryotes and organelles This enzyme is found in bacteria, mitochondria, plastids and as a constituent of the archaeal exosome (in those archaea that have an exosome). It can synthesise a 3′ extension where the vast majority of the bases are adenines. Like in bacteria, polyadenylation by polynucleotide phosphorylase promotes degradation of the RNA in plastids and likely also archaea. |
Glossary of set theory B Glossary_of_set_theory > B Naive set theory 2. A weak set theory, given by Kripke–Platek set theory without the axiom of collection. Sometimes also called "rudimentary set theory". |
Contractive mapping theorem Converses Contractive_mapping_theorem > Converses Several converses of the Banach contraction principle exist. The following is due to Czesław Bessaga, from 1959: Let f: X → X be a map of an abstract set such that each iterate fn has a unique fixed point. Let q ∈ ( 0 , 1 ) , {\displaystyle q\in (0,1),} then there exists a complete metric on X such that f is contractive, and q is the contraction constant. Indeed, very weak assumptions suffice to obtain such a kind of converse. For example if f: X → X {\displaystyle f:X\to X} is a map on a T1 topological space with a unique fixed point a, such that for each x ∈ X {\displaystyle x\in X} we have fn(x) → a, then there already exists a metric on X with respect to which f satisfies the conditions of the Banach contraction principle with contraction constant 1/2. In this case the metric is in fact an ultrametric. |
Multivariate adaptive regression spline Generalized cross validation Multivariate_adaptive_regression_spline > The model building process > The backward pass > Generalized cross validation The EffectiveNumberOfParameters is defined in the MARS context as (effective number of parameters) = (number of mars terms) + (penalty) · ((number of Mars terms) − 1 ) / 2where penalty is about 2 or 3 (the MARS software allows the user to preset penalty). Note that (number of Mars terms − 1 ) / 2is the number of hinge-function knots, so the formula penalizes the addition of knots. Thus the GCV formula adjusts (i.e. increases) the training RSS to take into account the flexibility of the model. |
Pulmonary tuberculosis Medication resistance Epidemiology_of_tuberculosis > Treatment > Medication resistance There is some efficacy for linezolid to treat those with XDR-TB but side effects and discontinuation of medications were common. Bedaquiline is tentatively supported for use in multiple drug-resistant TB.XDR-TB is a term sometimes used to define extensively resistant TB, and constitutes one in ten cases of MDR-TB. Cases of XDR TB have been identified in more than 90% of countries.For those with known rifampicin or MDR-TB, molecular tests such as the Genotype MTBDRsl Assay (performed on culture isolates or smear positive specimens) may be useful to detect second-line anti-tubercular drug resistance. |
Bacterial flagellum Structure and composition Flagellar_motility > Types > Bacterial > Structure and composition In most bacteria that have been studied, including the Gram-negative Escherichia coli, Salmonella typhimurium, Caulobacter crescentus, and Vibrio alginolyticus, the filament is made up of 11 protofilaments approximately parallel to the filament axis. Each protofilament is a series of tandem protein chains. However, Campylobacter jejuni has seven protofilaments.The basal body has several traits in common with some types of secretory pores, such as the hollow, rod-like "plug" in their centers extending out through the plasma membrane. The similarities between bacterial flagella and bacterial secretory system structures and proteins provide scientific evidence supporting the theory that bacterial flagella evolved from the type-three secretion system. |
Martin Vetterli Scientific contributions Martin_Vetterli > Career > Scientific contributions Martin Vetterli works in the areas of electrical engineering, computer science and applied mathematics. His work covers wavelets and applications, image and video compression (data compression), self-organized communications systems and sensor networks, as well as fast algorithms. At the core of his laboratory's current research is mathematical signal processing, that is, the set of tools and algorithms from applied harmonic analysis that are central to signal processing. These include representations for signals (Fourier, wavelets, frames), sampling theory, and sparse representations. |
Cellular compartment Summary Cell_compartment Cellular compartments in cell biology comprise all of the closed parts within the cytosol of a eukaryotic cell, usually surrounded by a single or double lipid layer membrane. These compartments are often, but not always, defined as membrane-bound organelles. The formation of cellular compartments is called compartmentalization. |
Binary cycle power station Secondary cycle Binary_cycle > Introduction > Secondary cycle Cold high-pressure working fluid is heated and vapourised in a heat exchanger by the hot geofluid. The hot high-pressure vapour is expanded in a turbine before being cooled and condensed in a condenser. To close the loop, the cold low-pressure liquid is repressurised via a feed pump. The secondary cycle is a closed cycle. The two main secondary cycle configurations are Organic Rankine cycles (ORC) or Kalina cycles, the main difference being the choice of working fluid; an organic fluid (commonly a hydrocarbon or refrigerant) or a water-ammonia mixture respectively. |
Parallel addition (operator) Quadratic formula Series-parallel_duality > Properties > Quadratic formula A linear equation can be easily solved via the parallel inverse: a x ∥ b = ∞ ⟹ x = − b a . {\displaystyle {\begin{aligned}ax\parallel b&=\infty \\\implies x&=-{\frac {b}{a}}.\end{aligned}}} To solve a parallel quadratic equation, complete the square to obtain an analog of the quadratic formula a x 2 ∥ b x ∥ c = ∞ x 2 ∥ b a x = − c a x 2 ∥ b a x ∥ 4 b 2 a 2 = ( − c a ) ∥ 4 b 2 a 2 ( x ∥ 2 b a ) 2 = b 2 ∥ − 1 4 a c 1 4 a 2 ⟹ x = ( − b ) ∥ ± b 2 ∥ − 1 4 a c 1 2 a . {\displaystyle {\begin{aligned}ax^{2}\parallel bx\parallel c&=\infty \\x^{2}\parallel {\frac {b}{a}}x&=-{\frac {c}{a}}\\x^{2}\parallel {\frac {b}{a}}x\parallel {\frac {4b^{2}}{a^{2}}}&=\left(-{\frac {c}{a}}\right)\parallel {\frac {4b^{2}}{a^{2}}}\\\left(x\parallel {\frac {2b}{a}}\right)^{2}&={\frac {b^{2}\parallel -{\tfrac {1}{4}}ac}{{\tfrac {1}{4}}a^{2}}}\\\implies x&={\frac {(-b)\parallel \pm {\sqrt {b^{2}\parallel -{\tfrac {1}{4}}ac}}}{{\tfrac {1}{2}}a}}.\end{aligned}}} |
Chemiosmotic hypothesis Proton-motive force Proton-motive_force > Proton-motive force In most cases the proton-motive force is generated by an electron transport chain which acts as a proton pump, using the Gibbs free energy of redox reactions to pump protons (hydrogen ions) out across the membrane, separating the charge across the membrane. In mitochondria, energy released by the electron transport chain is used to move protons from the mitochondrial matrix (N side) to the intermembrane space (P side). Moving the protons out of the mitochondrion creates a lower concentration of positively charged protons inside it, resulting in excess negative charge on the inside of the membrane. |
Cryptographic key types Key types Cryptographic_key_types > Key types Public key transport key Public key transport keys are the public keys of asymmetric key pairs that are used to encrypt keys using a public key algorithm. These keys are used to establish keys (e.g., key wrapping keys, data encryption keys or MAC keys) and, optionally, other keying material (e.g., Initialization Vectors). Symmetric key agreement key These symmetric keys are used to establish keys (e.g., key wrapping keys, data encryption keys, or MAC keys) and, optionally, other keying material (e.g., Initialization Vectors) using a symmetric key agreement algorithm. |
Robotic governance Summary Robotic_governance This is realized by the Robotic Governance Foundation, an international non-profit organization.The robotic governance approach is based on the German research on discourse ethics. Therefore, the discussion should involve all Stakeholders, including scientists, society, religion, politics, industry as well as labor unions in order to reach a consensus on how to shape the future of robotics and artificial intelligence. |
Enantiostasis Summary Enantiostasis Rather than maintaining homeostatic (stable ideal) conditions, enantiostasis involves maintaining only functionality in spite of external fluctuations. However, it can be considered a type of homeostasis in a broader context because functions are kept relatively consistent. Organic compounds such as Taurine have been shown to still properly function within environments that have been disrupted from an ideal state.The term enantiostasis was proposed by Mangum and Towle. It is derived from the Greek ἐναντίος (enantio-; opposite, opposing, over against) and στάσις (stasis; to stand, posture). |
Hepatocellular carcinoma Pathogenesis Hepatocellular_carcinoma > Pathogenesis Hepatocellular carcinoma, like any other cancer, develops when epigenetic alterations and mutations affecting the cellular machinery cause the cell to replicate at a higher rate and/or result in the cell avoiding apoptosis.In particular, chronic infections of hepatitis B and/or C can aid the development of hepatocellular carcinoma by repeatedly causing the body's own immune system to attack the liver cells, some of which are infected by the virus, others merely bystanders. Activated immune-system inflammatory cells release free radicals, such as reactive oxygen species and nitric oxide reactive species, which in turn can cause DNA damage and lead to carcinogenic gene mutations. Reactive oxygen species also cause epigenetic alterations at the sites of DNA repair.While this constant cycle of damage followed by repair can lead to mistakes during repair, which in turn lead to carcinogenesis, this hypothesis is more applicable, at present, to hepatitis C. Chronic hepatitis C causes HCC through the stage of cirrhosis. In chronic hepatitis B, however, the integration of the viral genome into infected cells can directly induce a noncirrhotic liver to develop HCC. |
UV photolysis Energy transfer models UV_photolysis > Photolysis in photosynthesis > Energy transfer models Photolysis during photosynthesis occurs in a series of light-driven oxidation events. The energized electron (exciton) of P680 is captured by a primary electron acceptor of the photosynthetic electron transport chain and thus exits photosystem II. In order to repeat the reaction, the electron in the reaction center needs to be replenished. |
Resting heart rate Correlation with cardiovascular mortality risk Heart_Rate > Clinical significance > Correlation with cardiovascular mortality risk Diet has also been found to be beneficial in lowering resting heart rate: In studies of resting heart rate and risk of death and cardiac complications on patients with type 2 diabetes, legumes were found to lower resting heart rate. This is thought to occur because in addition to the direct beneficial effects of legumes, they also displace animal proteins in the diet, which are higher in saturated fat and cholesterol. Another nutrient is omega-3 long chain polyunsaturated fatty acids (omega-3 fatty acid or LC-PUFA). |
Neural backpropagation History Neural_backpropagation > History Backpropagation occurs actively in the neocortex, hippocampus, substantia nigra, and spinal cord, while in the cerebellum it occurs relatively passively. This is consistent with observations that synaptic plasticity is much more apparent in areas like the hippocampus, which controls spatial memory, than the cerebellum, which controls more unconscious and vegetative functions. The backpropagating current also causes a voltage change that increases the concentration of Ca2+ in the dendrites, an event which coincides with certain models of synaptic plasticity. This change also affects future integration of signals, leading to at least a short-term response difference between the presynaptic signals and the postsynaptic spike. |
Acquired immunity Lymphocytes Active_immunity > Lymphocytes T and B lymphocytes are the cells of the adaptive immune system. The human body has about 2 trillion lymphocytes, which are 20–40% of white blood cells; their total mass is about the same as the brain or liver. The peripheral bloodstream contains only 2% of all circulating lymphocytes; the other 98% move within tissues and the lymphatic system, which includes the lymph nodes and spleen. |
Piezo effect Potential applications Piezoelectric_ceramics > Application > Potential applications In Israel, there is a company which has installed piezoelectric materials under a busy highway. The energy generated is enough to power street lights, billboards, and signs.Tire company Goodyear has plans to develop an electricity generating tire which has piezoelectric material lined inside it. As the tire moves, it deforms and thus electricity is generated.The efficiency of a hybrid photovoltaic cell that contains piezoelectric materials can be increased simply by placing it near a source of ambient noise or vibration. |
Interpersonal adaptation theory Theory Interpersonal_adaptation_theory > Theory This change minimizes the discrepancy gap between IP and A. By changing their IP, the interactant hopes their partner will acknowledge the adjustment by matching the behavior, thus changing A. Burgoon et al., describes this as a "Follow the Leader" entrainment principle. This is a strategic adaptation which was introduced by Ickes et al., in 1982.In summation, interpersonal adaptation theory explains the dyadic interaction as follows, prior to an individual entering an interaction with another individual, their interaction is predisposed with certain expectations, desires, and requirements, or an interaction position. Once the communication begins, the difference between interaction position and the other party's actual behavior determines whether the individual will adapt and continue the communication positively or not. == References == |
Legitimate power Coercive power Coercive_power > Bases of power > Coercive power Coercive power uses the threat of force to gain compliance from another. Force may include physical, social, emotional, political, or economic means. Coercion is not always recognized by the target of influence. This type of power is based upon the idea of coercion. |
Complex plane Complex numbers Gauss_plane > Notational conventions > Complex numbers For example, the unit circle is traversed in the positive direction when we start at the point z = 1, then travel up and to the left through the point z = i, then down and to the left through −1, then down and to the right through −i, and finally up and to the right to z = 1, where we started. Almost all of complex analysis is concerned with complex functions – that is, with functions that map some subset of the complex plane into some other (possibly overlapping, or even identical) subset of the complex plane. Here it is customary to speak of the domain of f(z) as lying in the z-plane, while referring to the range of f(z) as a set of points in the w-plane. In symbols we write and often think of the function f as a transformation from the z-plane (with coordinates (x, y)) into the w-plane (with coordinates (u, v)). |
Postgres License Indexes Postgres_License > Storage and replication > Indexes PostgreSQL includes built-in support for regular B-tree and hash table indexes, and four index access methods: generalized search trees (GiST), generalized inverted indexes (GIN), Space-Partitioned GiST (SP-GiST) and Block Range Indexes (BRIN). In addition, user-defined index methods can be created, although this is quite an involved process. Indexes in PostgreSQL also support the following features: Expression indexes can be created with an index of the result of an expression or function, instead of simply the value of a column. Partial indexes, which only index part of a table, can be created by adding a WHERE clause to the end of the CREATE INDEX statement. |
Finite semigroup History and applications Finite_semigroup > History and applications In the general case, these are embedded in a larger structure with a hierarchical "coordinate system". One must be careful in understanding the notion of "prime" as Krohn and Rhodes explicitly refer to their theorem as a "prime decomposition theorem" for automata. The components in the decomposition, however, are not prime automata (with prime defined in a naïve way); rather, the notion of prime is more sophisticated and algebraic: the semigroups and groups associated to the constituent automata of the decomposition are prime (or irreducible) in a strict and natural algebraic sense with respect to the wreath product (Eilenberg, 1976). |
Euler's laws Explanation and derivation Euler's_second_law > Explanation and derivation Thus, the total applied torque M about the origin is given by M = M B + M C {\displaystyle \mathbf {M} =\mathbf {M} _{B}+\mathbf {M} _{C}} where MB and MC respectively indicate the moments caused by the body and contact forces. Thus, the sum of all applied forces and torques (with respect to the origin of the coordinate system) acting on the body can be given as the sum of a volume and surface integral: F = ∫ V a d m = ∫ V a ρ d V = ∫ S t d S + ∫ V b ρ d V {\displaystyle \mathbf {F} =\int _{V}\mathbf {a} \,dm=\int _{V}\mathbf {a} \rho \,dV=\int _{S}\mathbf {t} \,dS+\int _{V}\mathbf {b} \rho \,dV} M = M B + M C = ∫ S r × t d S + ∫ V r × b ρ d V . {\displaystyle \mathbf {M} =\mathbf {M} _{B}+\mathbf {M} _{C}=\int _{S}\mathbf {r} \times \mathbf {t} \,dS+\int _{V}\mathbf {r} \times \mathbf {b} \rho \,dV.} |
Home lift Overview Home_lift > Overview When the lift is operated, the engine forces the nut to rotate around the screw, pushing the lift up and down. Most home lifts come with an open platform structure to free even more space and grant access from 3 different sides of the platform. This requires all producers to include specific safety mechanisms and, in some countries, to limit the travel speed.Home lifts have been present on the market for decades, and represent a growing trend. |
Physical organic Substituent effects Physical_organic_chemistry > Kinetics > Substituent effects Hammett analysis can be used to help elucidate the possible mechanisms of a reaction. For example, if it is predicted that the transition state structure has a build-up of negative charge relative to the ground state structure, then electron-donating groups would be expected to increase the rate of the reaction.Other LFER scales have been developed. Steric and polar effects are analyzed through Taft Parameters. Changing the solvent instead of the reactant can provide insight into changes in charge during the reaction. The Grunwald-Winstein Plot provides quantitative insight into these effects. |
Biogas plant Bio-gas Plants Sewage_gas > Production > Industrial > Bio-gas Plants A biogas plant is the name often given to an anaerobic digester that treats farm wastes or energy crops. It can be produced using anaerobic digesters (air-tight tanks with different configurations). These plants can be fed with energy crops such as maize silage or biodegradable wastes including sewage sludge and food waste. During the process, the micro-organisms transform biomass waste into biogas (mainly methane and carbon dioxide) and digestate. Higher quantities of biogas can be produced when the wastewater is co-digested with other residuals from the dairy industry, sugar industry, or brewery industry. For example, while mixing 90% of wastewater from beer factory with 10% cow whey, the production of biogas was increased by 2.5 times compared to the biogas produced by wastewater from the brewery only.Manufacturing of biogas from intentionally planted maize has been described as being unsustainable and harmful due to very concentrated, intense and soil eroding character of these plantations. |
Discovery of nuclear fission Interpretation Discovery_of_nuclear_fission > Discovery > Interpretation Breaking it up seemed far more difficult. However the liquid drop model that Gamow had postulated suggested the possibility that an atomic nucleus could become elongated and overcome the surface tension that held it together. According to Frisch:At that point we both sat down on a tree trunk (all that discussion had taken place while we walked through the wood in the snow, I with my skis on, Lise Meitner making good her claim that she could walk just as fast without), and started to calculate on scraps of paper. |
Bokashi (horticulture) Carbon, gases and energy Bokashi_(horticulture) > Characteristics > Emissions > Carbon, gases and energy Homolactic fermentation and similar anaerobic fermentation pathways in general provide a very small amount of energy to the cell compared to the aerobic process. In homolactic fermentation, 2 ATP molecules are made when one glucose molecule (produced by digesting complex carbohydrates) is converted to 2 lactic acid molecules, only 1⁄15 of what aerobic respiration provides. The process will also halt before all available carbohydrates are used, as the acidity ends up inhibiting all bacteria. As a result, a bokashi bucket barely heats up and remains at ambient temperature.As a waste processing technique, bokashi is notable in that minimal loss of mass in the form of offgassing happens. |
Algorithmic learning theory Learning in the limit Algorithmic_learning_theory > Learning in the limit However the framework is very powerful, because if these strict conditions are maintained, it allows the learning of any program known to be computable. This is because a Turing machine program can be written to mimic any program in any conventional programming language. See Church-Turing thesis. |
Oversampled binary image sensor Working principle Oversampled_binary_image_sensor > Working principle The original motivation was mainly out of technical necessity. The miniaturization of camera systems calls for the continuous shrinking of pixel sizes. At a certain point, however, the limited full-well capacity (i.e., the maximum photon-electrons a pixel can hold) of small pixels becomes a bottleneck, yielding very low signal-to-noise ratios (SNRs) and poor dynamic ranges. In contrast, a binary sensor whose pixels need to detect only a few photon-electrons around a small threshold q has much less requirement for full-well capacities, allowing pixel sizes to shrink further. |
Carbocation Structure and properties Carbocation > Structure and properties Strongly basic nucleophiles, especially hindered ones, favor elimination over addition. Because even weak nucleophiles will react with carbocations, most can only be directly observed or isolated in non-nucleophilic media like superacids. Carbocations typically undergo rearrangement reactions from less stable structures to equally stable or more stable ones by migration of an alkyl group or hydrogen to the cationic center to form a new carbocationic center. |
V-model Summary V-model The easiest way is to say that verification is always against the requirements (technical terms) and validation always against the real world or the user needs. The aerospace standard RTCA DO-178B states that requirements are validated—confirmed to be true—and the end product is verified to ensure it satisfies those requirements. Validation can be expressed with the query "are you building the right thing?" and verification with "are you building it right?" |
Potassium cycle Summary Potassium_cycle The potassium (K) cycle is the biogeochemical cycle that describes the movement of potassium throughout the Earth’s lithosphere, biosphere, atmosphere, and hydrosphere. |
Law of conservation of complexity Background Law_of_conservation_of_complexity > Background However, Bruce Tognazzini proposes that people resist reductions to the amount of complexity in their lives. Thus, when an application is simplified, users begin attempting more complex tasks. Many other consultants, however, have stated on social media that this is not a law at all. While acknowledging the tradeoff between how the software is built and how it is used happens, it is not inherent. Instead, it is mostly due to a poor architecture and not attending to the customer journey the product is in. |
Phragmosome Summary Phragmosome It disappears as soon as the nuclear envelope breaks down and the mitotic spindle forms. When mitosis is completed, the cell plate and new cell wall form starting from the center along the plane occupied by the phragmosome. The cell plate grows outwards until it fuses with the cell wall of the dividing cell at exactly the spots predicted by the preprophase band. |
Euclidean ring Examples Euclidean_ring > Examples Examples of Euclidean domains include: Any field. Define f (x) = 1 for all nonzero x. Z, the ring of integers. Define f (n) = |n|, the absolute value of n. Z, the ring of Gaussian integers. Define f (a + bi) = a2 + b2, the norm of the Gaussian integer a + bi. |
Group 7 element Summary Group_7_element Group 7, numbered by IUPAC nomenclature, is a group of elements in the periodic table. It contains manganese (Mn), technetium (Tc), rhenium (Re) and bohrium (Bh). This group lies in the d-block of the periodic table, and are hence transition metals. This group is sometimes called the manganese group or manganese family after its lightest member; however, the group itself has not acquired a trivial name because it belongs to the broader grouping of the transition metals. Like other groups, the members of this family show patterns in their electron configurations, especially the outermost shells resulting in trends in chemical behavior. |
Glossary of electrical and electronics engineering R Glossary_of_electrical_and_electronics_engineering > R rectifierA device that converts alternating current (which periodically reverses) to direct current that flows in only one direction; may be a solid-state, vacuum tube or electromechanical device. rectiformerA combination of a transformer and a rectifier, used in electrochemical processes or supply of electrostatic precipitators. |
Electronic map Scale and accuracy Map_orientation > Scale and accuracy Although the scale statement is nominal it is usually accurate enough for most purposes unless the map covers a large fraction of the earth. At the scope of a world map, scale as a single number is practically meaningless throughout most of the map. Instead, it usually refers to the scale along the equator. |
Bicycle gearing Relative gearing Bicycle_gearing > General considerations > Relative gearing As far as a cyclist's legs are concerned, when changing gears, the relative difference between two gears is more important than the absolute difference between gears. This relative change, from a lower gear to a higher gear, is normally expressed as a percentage, and is independent of what system is used to measure the gears. Cycling tends to feel more comfortable if nearly all gear changes have more or less the same percentage difference. |
Continuous simulation History Continuous_simulation > History Their first publication strongly suggested that the Navy was wasting a lot of money through the inconclusive flight-testing of missiles, but that the Simulation Council's analog computer could provide better information through the simulation of flights. Since that time continuous simulation has been proven invaluable in military and private endeavors with complex systems. No Apollo moon shot would have been possible without it. |
NaBiO3 Reactions Sodium_bismuthate > Reactions Permanganate has a violet color and maximum absorbance at 510 nm. The reaction is: 2 Mn2+ + 5 NaBiO3 + 14 H+ → 2 MnO−4 + 5 Bi3+ + 5 Na+ + 7 H2OSodium bismuthate can perform oxidative 1,2-cleavage on glycols, ketols and alpha hydroxy acids with no further oxidation of the (possible) aldehyde products: R2C(OH)–C(OH)–R2 → R2C=O + O=CR2 R2C(OH)–C(O)–R → R2C=O + RCOOH R2C(OH)–COOH → R2C=O + CO2These cleavages can be done in the presence of acetic or phosphoric acid at room temperature. Alcohols like methanol or ethanol can be used as the reaction media, as they are oxidized slowly with sodium bismuthate. Lead tetraacetate performs similar reactions, but anhydrous conditions, as required in the use of lead tetraacetate, are not necessary for sodium bismuthate.NaBiO3 can be used for lab-scale plutonium separation (see bismuth phosphate process). |
Euclidean traveling salesman problem Exact algorithms Travelling_salesman_problem > Computing a solution > Exact algorithms The total computation time was equivalent to 22.6 years on a single 500 MHz Alpha processor. In May 2004, the travelling salesman problem of visiting all 24,978 towns in Sweden was solved: a tour of length approximately 72,500 kilometres was found and it was proven that no shorter tour exists. In March 2005, the travelling salesman problem of visiting all 33,810 points in a circuit board was solved using Concorde TSP Solver: a tour of length 66,048,945 units was found and it was proven that no shorter tour exists. The computation took approximately 15.7 CPU-years (Cook et al. 2006). In April 2006 an instance with 85,900 points was solved using Concorde TSP Solver, taking over 136 CPU-years, see Applegate et al. (2006). |
Constants of integration Summary Integration_constant In calculus, the constant of integration, often denoted by C {\displaystyle C} (or c {\displaystyle c} ), is a constant term added to an antiderivative of a function f ( x ) {\displaystyle f(x)} to indicate that the indefinite integral of f ( x ) {\displaystyle f(x)} (i.e., the set of all antiderivatives of f ( x ) {\displaystyle f(x)} ), on a connected domain, is only defined up to an additive constant. This constant expresses an ambiguity inherent in the construction of antiderivatives. More specifically, if a function f ( x ) {\displaystyle f(x)} is defined on an interval, and F ( x ) {\displaystyle F(x)} is an antiderivative of f ( x ) , {\displaystyle f(x),} then the set of all antiderivatives of f ( x ) {\displaystyle f(x)} is given by the functions F ( x ) + C , {\displaystyle F(x)+C,} where C {\displaystyle C} is an arbitrary constant (meaning that any value of C {\displaystyle C} would make F ( x ) + C {\displaystyle F(x)+C} a valid antiderivative). For that reason, the indefinite integral is often written as ∫ f ( x ) d x = F ( x ) + C , {\textstyle \int f(x)\,dx=F(x)+C,} although the constant of integration might be sometimes omitted in lists of integrals for simplicity. |
Classification (machine learning) Binary and multiclass classification Algorithms_for_statistical_classification > Binary and multiclass classification Classification can be thought of as two separate problems – binary classification and multiclass classification. In binary classification, a better understood task, only two classes are involved, whereas multiclass classification involves assigning an object to one of several classes. Since many classification methods have been developed specifically for binary classification, multiclass classification often requires the combined use of multiple binary classifiers. |
Rational conformal field theory Summary Rational_conformal_field_theory More generally, rational conformal field theory can refer to any CFT with a finite number of primary operators with respect to the action of its chiral algebra. Chiral algebras can be much larger than the Virasoro algebra. Well-known examples include (the enveloping algebra of) affine Lie algebras, relevant to the Wess–Zumino–Witten model, and W-algebras. |
Difference due to memory Main paradigms Difference_due_to_memory > Main paradigms Critically for the Dm effect, the responses a participant makes to the old items in the test phase are used to backsort trials in the study phase as either "subsequently remembered" or "subsequently forgotten." If during the test phase a participant correctly classifies an old item as old, it falls into the "subsequently remembered" trial type for the study phase. On the other hand, if a person incorrectly calls an old item new at the test phase, or fails to respond "old" to an old item, this item becomes classified as "subsequently forgotten." |
Store energy History Electrochemical_energy_storage > History Interest in storing power from these intermittent sources grows as the renewable energy industry begins to generate a larger fraction of overall energy consumption.Off grid electrical use was a niche market in the 20th century, but in the 21st century, it has expanded. Portable devices are in use all over the world. Solar panels are now common in the rural settings worldwide. |
Digital Taylorism Influences on the workplace Digital_Taylorism > Influences on the workplace Schools are finding new ways to make sure students are being taught the most efficient methods in order to succeed and meet the standards. New Taylorism can be seen through the written curriculum in schools in the United States.Another example of Digital Taylorism being used in the workplace is found in organizations who use surveillance systems to monitor workers and make sure they are on task at all times; the percentage of surveillance being used in the workplace is continually growing. Phones and computers that employees use at work are being monitored in order to make sure everything is being done in the most efficient way. |
Proth's theorem Numerical examples Proth's_theorem > Numerical examples Examples of the theorem include: for p = 3 = 1(21) + 1, we have that 2(3-1)/2 + 1 = 3 is divisible by 3, so 3 is prime. for p = 5 = 1(22) + 1, we have that 3(5-1)/2 + 1 = 10 is divisible by 5, so 5 is prime. for p = 13 = 3(22) + 1, we have that 5(13-1)/2 + 1 = 15626 is divisible by 13, so 13 is prime. for p = 9, which is not prime, there is no a such that a(9-1)/2 + 1 is divisible by 9.The first Proth primes are (sequence A080076 in the OEIS): 3, 5, 13, 17, 41, 97, 113, 193, 241, 257, 353, 449, 577, 641, 673, 769, 929, 1153 ….The largest known Proth prime as of 2016 is 10223 ⋅ 2 31172165 + 1 {\displaystyle 10223\cdot 2^{31172165}+1} , and is 9,383,761 digits long. |
Lesional demyelinations of the central nervous system MS lesions Lesional_demyelinations_of_the_central_nervous_system > Lesions produced by CNS Inflammatory Demyelinating diseases (IDS) > Confluent demyelination > MS lesions Normally MS lesions are small ovoid lesions, less than 2 cm. long, oriented perpendicular to the long axis of the brain's ventricles Often they are disposed surrounding a vein Active and pre-active lesions appear as hyperintense areas under T2-weighted MRI. Pre-active lesion here refers to lesions localized in the normal appearing white matter, without apparent loss of myelin but nevertheless showing a variable degree of oedema, small clusters of microglial cells with enhanced major histocompatibility complex class II antigen, CD45 and CD68 antigen expression and a variable number of perivascular lymphocytes around small blood vesselsUsing high field MRI system, with several variants several areas show lesions, and can be spacially classified in infratentorial, callosal, juxtacortical, periventricular, and other white matter areas. Other authors simplify this in three regions: intracortical, mixed gray-white matter, and juxtacortical. |
Work energy theorem Work by a gas Work–energy_principle > Work and potential energy > Work by a gas The work W {\displaystyle W} done by a body of gas on its surroundings is: where P is pressure, V is volume, and a and b are initial and final volumes. |
Melioidosis Age, risk factors Melioidosis > Epidemiology > Age, risk factors Diabetes decreases the ability of macrophages to fight the bacteria and reduced the T helper cell production. Excessive release of Tumor necrosis factor alpha and Interleukin 12 by mononuclear cells increases the risk of septic shock. Other risk factors include thalassaemia, occupational exposure (e.g. rice paddy farmers), recreational exposure to soil, water, being male, age greater than 45 years, and prolonged steroid use/immunosuppression. |
First ring isomorphism theorem Summary Noether_isomorphism_theorem In mathematics, specifically abstract algebra, the isomorphism theorems (also known as Noether's isomorphism theorems) are theorems that describe the relationship between quotients, homomorphisms, and subobjects. Versions of the theorems exist for groups, rings, vector spaces, modules, Lie algebras, and various other algebraic structures. In universal algebra, the isomorphism theorems can be generalized to the context of algebras and congruences. |
Natural unit Schrödinger units Natural_unit > Systems of natural units > Schrödinger units A system of units in which ℏ = e = G = 1 {\displaystyle \hbar =e=G=1} and c = 1 / α {\displaystyle c=1/\alpha } is seldom mentioned in literature as Schrödinger's system of units (after Austrian physicist Erwin Schrödinger).In this system of units the speed of light changes in inverse proportion to the fine structure constant, therefore it has gained some interest recent years in the niche hypothesis of time-variation of fundamental constants. |
Asymmetrical aircraft Engine torque Asymmetrical_aircraft > Types of asymmetry > Engine torque This gives it an especially powerful torque reaction. Some aircraft, such as the Sopwith Camel with its relatively heavy Clerget 9B engine, were noted for having a faster turn to one side than the other, which influenced combat tactics both with it and against it. By contrast, the contra-rotary Siemens-Halske engines were more balanced. |
5-HT2A receptor Summary 5-HT2A_receptor This receptor was first noted for its importance as a target of serotonergic psychedelic drugs such as LSD and psilocybin mushrooms. Later it came back to prominence because it was also found to be mediating, at least partly, the action of many antipsychotic drugs, especially the atypical ones. Downregulation of post-synaptic 5-HT2A receptor is an adaptive process provoked by chronic administration of selective serotonin reuptake inhibitors (SSRIs) and atypical antipsychotics. |
Siméon Denis Poisson Wave propagation Siméon_Denis_Poisson > Contributions > Mechanics > Wave propagation Poisson also published a memoir on the theory of waves (Mém. ft. l'acad., 1825). |
Electric system Generation and transmission Electric_system > Production, storage and uses > Generation and transmission Such generators bear no resemblance to Faraday's homopolar disc generator of 1831, but they still rely on his electromagnetic principle that a conductor linking a changing magnetic field induces a potential difference across its ends. Electricity generated by solar panels rely on a different mechanism: solar radiation is converted directly into electricity using the photovoltaic effect. Demand for electricity grows with great rapidity as a nation modernises and its economy develops. The United States showed a 12% increase in demand during each year of the first three decades of the twentieth century, a rate of growth that is now being experienced by emerging economies such as those of India or China.Environmental concerns with electricity generation, in specific the contribution of fossil fuel burning to climate change, have led to an increased focus on generation from renewable sources. In the power sector, wind and solar have become cost effective, speeding up an energy transition away from fossil fuels. |
Faster-than-light travel Light spots and shadows Causality_problem > Superluminal travel of non-information > Light spots and shadows If a laser beam is swept across a distant object, the spot of laser light can easily be made to move across the object at a speed greater than c. Similarly, a shadow projected onto a distant object can be made to move across the object faster than c. In neither case does the light travel from the source to the object faster than c, nor does any information travel faster than light. |
Clostridial necrotizing enteritis Treatment Clostridial_necrotizing_enteritis > Treatment The choice is also guided by the local susceptibility patterns (ie, the local antibiogram in a particular neonatal intensive care unit ). Acceptable empiric regimens include, but are not limited to, the following:•Ampicillin plus gentamicin (or amikacin) plus metronidazole •Ampicillin plus gentamicin (or amikacin) plus clindamycin •Ampicillin plus an expanded-spectrum cephalosporin (eg, cefotaxime , ceftazidime, or cefepime) plus metronidazole •Monotherapy with piperacillin-tazobactam •Monotherapy with meropenem Vancomycin should be included in the regimen (ie, replacing ampicillin or added to monotherapy) in centers where there is a high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) or ampicillin-resistant enterococcal infections. Centers with significant gentamicin resistance patterns should consider amikacin in place of gentamicin. The use of oral aminoglycosides is not recommended because it can result in the development of resistant bacterial strains, and has not been shown to be more beneficial than standard care. |
Clinical Data Interchange Standards Consortium Operational Data Model (ODM) Clinical_Data_Interchange_Standards_Consortium > Individual standards > Operational Data Model (ODM) ODM is often combined with the Study Data Model standard to more fully model trial arms or trial activities. ODM is also used in sending forms data from a clinical trial system to an electronic health record (EHR) system. The ODM schema is generally divided into three categories of data: Metadata, Admin data, and Clinical data. |
Sufficient statistic Bernoulli distribution Sufficient_statistic > Examples > Bernoulli distribution If X1, ...., Xn are independent Bernoulli-distributed random variables with expected value p, then the sum T(X) = X1 + ... + Xn is a sufficient statistic for p (here 'success' corresponds to Xi = 1 and 'failure' to Xi = 0; so T is the total number of successes) This is seen by considering the joint probability distribution: Pr { X = x } = Pr { X 1 = x 1 , X 2 = x 2 , … , X n = x n } . {\displaystyle \Pr\{X=x\}=\Pr\{X_{1}=x_{1},X_{2}=x_{2},\ldots ,X_{n}=x_{n}\}.} Because the observations are independent, this can be written as p x 1 ( 1 − p ) 1 − x 1 p x 2 ( 1 − p ) 1 − x 2 ⋯ p x n ( 1 − p ) 1 − x n {\displaystyle p^{x_{1}}(1-p)^{1-x_{1}}p^{x_{2}}(1-p)^{1-x_{2}}\cdots p^{x_{n}}(1-p)^{1-x_{n}}} and, collecting powers of p and 1 − p, gives p ∑ x i ( 1 − p ) n − ∑ x i = p T ( x ) ( 1 − p ) n − T ( x ) {\displaystyle p^{\sum x_{i}}(1-p)^{n-\sum x_{i}}=p^{T(x)}(1-p)^{n-T(x)}} which satisfies the factorization criterion, with h(x) = 1 being just a constant. Note the crucial feature: the unknown parameter p interacts with the data x only via the statistic T(x) = Σ xi. As a concrete application, this gives a procedure for distinguishing a fair coin from a biased coin. |
Linear optical quantum computing Ingredients Linear_optical_quantum_computing > Ingredients DiVincenzo's criteria for quantum computation and QIP give that a universal system for QIP should satisfy at least the following requirements: a scalable physical system with well characterized qubits, the ability to initialize the state of the qubits to a simple fiducial state, such as | 000 ⋯ ⟩ {\displaystyle |000\cdots \rangle } , long relevant decoherence times, much longer than the gate operation time, a "universal" set of quantum gates (this requirement cannot be satisfied by a non-universal system), a qubit-specific measurement capability;if the system is also aiming for quantum communication, it should also satisfy at least the following two requirements: the ability to interconvert stationary and flying qubits, and the ability to faithfully transmit flying qubits between specified location.As a result of using photons and linear optical circuits, in general LOQC systems can easily satisfy conditions 3, 6 and 7. The following sections mainly focus on the implementations of quantum information preparation, readout, manipulation, scalability and error corrections, in order to discuss the advantages and disadvantages of LOQC as a candidate for QIP |
Oxidation reduction potential Summary Reduction_potential Redox potential (also known as oxidation / reduction potential, ORP, pe, E r e d {\displaystyle E_{red}} , or E h {\displaystyle E_{h}} ) is a measure of the tendency of a chemical species to acquire electrons from or lose electrons to an electrode and thereby be reduced or oxidised respectively. Redox potential is expressed in volts (V). Each species has its own intrinsic redox potential; for example, the more positive the reduction potential (reduction potential is more often used due to general formalism in electrochemistry), the greater the species' affinity for electrons and tendency to be reduced. |
SQL Server Analysis Services Partition storage modes SQL_Server_Analysis_Services > Multidimensional Storage modes > Partition storage modes MOLAP - Multidimensional OLAP - Both fact data and aggregations are processed, stored, and indexed using a special format optimized for multidimensional data. ROLAP - Relational OLAP - Both fact data and aggregations remain in the relational data source, eliminating the need for special processing. HOLAP - Hybrid OLAP - This mode uses the relational data source to store the fact data, but pre-processes aggregations and indexes, storing these in a special format, optimized for multidimensional data. |
Arc routing Heuristics and algorithms Arc_routing > Heuristics and algorithms Most algorithms require a pre-processing of the graph, which simplifies the initial graph by removing all edges that are not in the shortest path between two required edges. Another simplification that the pre-processing adds is that it transforms the shortest path between 2 required edges into a single, non-required edge, regardless of the number of edges in the path, provided that there were no required edges in the path. Once the pre-processing is done, the problem can be generalized into a convex hull problem, with the edges being the points of the hull. The convex hull problem can be solved through linear programming or through convex hull algorithms, but the process of finding the convex hull is an exponential problem. Methods of solving the URPP after the pre-processing is done consist of the cutting plane algorithm and the branch & cut methodology. |
Tissue-resident memory T cell Potential of CD8+ TRM cells in cancer immunotherapy Tissue-resident_memory_T_cells > Potential of CD8+ TRM cells in cancer immunotherapy Cytotoxic CD8+ T lymphocytes are able to recognize malignant cells. Production of neoantigens by tumour cells can lead to peptides which are presented to CD8+ T cells bound to MHC I. After antigen recognition, CD8+ T cells destroy tumor cells using IFN-ɤ, TNF-α, granzyme B and perforin. However, malignant cells can avoid this elimination by various mechanisms such as the loss of MHC I molecule, induction of anti-inflammatory tumor micro-environment, inhibition of T cell function, upregulation of ligands whose interactions with CD8+ T cell receptors results in their suppression etc. Immune checkpoint therapy and tumor-infiltrating lymphocytes (TIL) therapy are cancer immunotherapy strategies whose principle lies in suppression of tumor cell inhibitory pathways or in introduction of expanded CD8+ T cells. Whereas large fraction of TILs are TRM cells, they are candidates for solid cancer immunotherapy.TRM cells infiltrated in tumors have protective role and are associated with good clinical results in various cancer types, but not in pancreatic cancer. |
Electromagnetic coil Transformers Electromagnetic_coil > Types of coils > Transformers Different portions of the winding, accessed with taps, act as primary and secondary windings of the transformer. Toroidal transformer - the core is in the shape of a toroid. This is a commonly used shape as it decreases the leakage flux, resulting in less electromagnetic interference. |
Elbio Dagotto Research Elbio_Dagotto > Research Dagotto's research has primarily focused on strongly correlated electronic materials, and lately in quantum materials, where correlation and topological effects are intertwined. In the presence of strong correlation, the interactions between electrons play a crucial role and the one-electron approximation, used for example in semiconductors, is no longer valid. In this framework, he has worked on theories for many families of materials, such as high critical temperature superconductors and manganese oxides with the colossal magnetoresistance. The overarching theme of his work is that correlated electrons must be considered in the broader context of complexity. |
Loedel diagram Non-relativistic "spacetime diagrams" Spacetime_diagram > Introduction to kinetic diagrams > Non-relativistic "spacetime diagrams" The black axes labelled x and ct on Fig 1-3 are the coordinate system of an observer, referred to as at rest, and who is positioned at x = 0. This observer's world line is identical with the ct time axis. Each parallel line to this axis would correspond also to an object at rest but at another position. The blue line describes an object moving with constant speed v to the right, such as a moving observer. |
Borda (crater) Summary Borda_(crater) The rim is intruded into by another small crater along the southwest side, and there is an irregular cleft along the northwest face. There is a central peak at the midpoint of the floor. == References == |
Digital platform (infrastructure) Summary Digital_platform_(infrastructure) A digital platform is a software-based online infrastructure that facilitates interactions and transactions between users. Digital platforms can act as data aggregators to help users navigate large amounts of information, as is the case with search engines; as matchmakers to enable transactions between users, as is the case with digital marketplaces; or as collaborative tools to support the development of new content, as is the case with online communities. Digital platforms can also combine several of these features, such as when a social media platform enables both searching for information and matchmaking between users.Digital platforms can be more or less decentralized in their data architecture and can be governed based on more or less distributed decision-making. |
Mathematical space Linear and topological spaces Space_(mathematics) > Types of spaces > Linear and topological spaces Two basic spaces are linear spaces (also called vector spaces) and topological spaces. Linear spaces are of algebraic nature; there are real linear spaces (over the field of real numbers), complex linear spaces (over the field of complex numbers), and more generally, linear spaces over any field. Every complex linear space is also a real linear space (the latter underlies the former), since each complex number can be specified by two real numbers. For example, the complex plane treated as a one-dimensional complex linear space may be downgraded to a two-dimensional real linear space. |
Panic disorder Cognitive behavioral therapy Panic_disorder > Treatment > Psychotherapy > Cognitive behavioral therapy Current treatment guidelines American Psychiatric Association and the American Medical Association primarily recommend either cognitive-behavioral therapy or one of a variety of psychopharmacological interventions. Some evidence exists supporting the superiority of combined treatment approaches.Another option is self-help based on principles of cognitive-behavioral therapy. Using a book or a website, a person does the kinds of exercises that would be used in therapy, but they do it on their own, perhaps with some email or phone support from a therapist. A systematic analysis of trials testing this kind of self-help found that websites, books, and other materials based on cognitive-behavioral therapy could help some people. The best-studied conditions are panic disorder and social phobia. |
Master equation Introduction Master_equation > Introduction A master equation is a phenomenological set of first-order differential equations describing the time evolution of (usually) the probability of a system to occupy each one of a discrete set of states with regard to a continuous time variable t. The most familiar form of a master equation is a matrix form: d P → d t = A P → , {\displaystyle {\frac {d{\vec {P}}}{dt}}=\mathbf {A} {\vec {P}},} where P → {\displaystyle {\vec {P}}} is a column vector, and A {\displaystyle \mathbf {A} } is the matrix of connections. The way connections among states are made determines the dimension of the problem; it is either a d-dimensional system (where d is 1,2,3,...), where any state is connected with exactly its 2d nearest neighbors, or a network, where every pair of states may have a connection (depending on the network's properties).When the connections are time-independent rate constants, the master equation represents a kinetic scheme, and the process is Markovian (any jumping time probability density function for state i is an exponential, with a rate equal to the value of the connection). When the connections depend on the actual time (i.e. matrix A {\displaystyle \mathbf {A} } depends on the time, A → A ( t ) {\displaystyle \mathbf {A} \rightarrow \mathbf {A} (t)} ), the process is not stationary and the master equation reads d P → d t = A ( t ) P → . {\displaystyle {\frac {d{\vec {P}}}{dt}}=\mathbf {A} (t){\vec {P}}.} |
Transition state theory Summary Transition-state_theory This theory was developed simultaneously in 1935 by Henry Eyring, then at Princeton University, and by Meredith Gwynne Evans and Michael Polanyi of the University of Manchester. TST is also referred to as "activated-complex theory", "absolute-rate theory", and "theory of absolute reaction rates".Before the development of TST, the Arrhenius rate law was widely used to determine energies for the reaction barrier. The Arrhenius equation derives from empirical observations and ignores any mechanistic considerations, such as whether one or more reactive intermediates are involved in the conversion of a reactant to a product. |
Stratification (water) Estuaries Stratification_(water) > By water body type > Estuaries Vertical mixing determines how much the salinity and temperature will change from the top to the bottom, profoundly affecting water circulation. Vertical mixing occurs at three levels: from the surface downward by wind forces, the bottom upward by turbulence generated at the interface between the estuarine and oceanic water masses, and internally by turbulent mixing caused by the water currents which are driven by the tides, wind, and river inflow.Different types of estuarine circulation result from vertical mixing: Salt wedge estuaries are characterized by a sharp density interface between the upper layer of freshwater and the bottom layer of saline water. River water dominates in this system, and tidal effects have a small role in the circulation patterns. |
List of integrals of rational functions Summary List_of_integrals_of_rational_functions The following is a list of integrals (antiderivative functions) of rational functions. Any rational function can be integrated by partial fraction decomposition of the function into a sum of functions of the form: which can then be integrated term by term. For other types of functions, see lists of integrals. |
Chemical reaction network Existence of stable periodic solutions Chemical_reaction_network_theory > Types of results > Existence of stable periodic solutions Results regarding stable periodic solutions attempt to rule out "unusual" behaviour. If a given chemical reaction network admits a stable periodic solution, then some initial conditions will converge to an infinite cycle of oscillating reactant concentrations. For some parameter values it may even exhibit quasiperiodic or chaotic behaviour. |
Loop Shuttle Summary Loop_Shuttle The Loop Shuttle was a rapid transit line on the Chicago "L". It operated clockwise around the Loop, making stops at all stations. The line was inaugurated September 30, 1969, and discontinued September 30, 1977. |
Chromatic phonogene Initial tools of musique concrète Musique_concrete > Technology > Initial tools of musique concrète Filters: two kinds of filters, third-octave octave filter banks and high- and low-pass filters. They allowed the elimination or enhancement of selected frequencies. Microphones: essential tool for capturing sound.The application of the above technologies in the creation of musique concrète led to the development of a number of sound manipulation techniques including: Sound transposition: reading a sound at a different speed than the one at which it was recorded. |
Micro RNA Heart disease Micro_RNA > Disease > Heart disease Furthermore, animal studies on specific miRNAs identified distinct roles for miRNAs both during heart development and under pathological conditions, including the regulation of key factors important for cardiogenesis, the hypertrophic growth response and cardiac conductance. Another role for miRNA in cardiovascular diseases is to use their expression levels for diagnosis, prognosis or risk stratification. miRNA's in animal models have also been linked to cholesterol metabolism and regulation. |
Theory of Categories Kant Ontological_catalogue > Modern development > Kant In each table the number twelve arises from, firstly, an initial division into two: the Mathematical and the Dynamical; a second division of each of these headings into a further two: Quantity and Quality, and Relation and Modality respectively; and, thirdly, each of these then divides into a further three subheadings as follows. Criticism of Kant's system followed, firstly, by Arthur Schopenhauer, who amongst other things was unhappy with the term "Community", and declared that the tables "do open violence to truth, treating it as nature was treated by old-fashioned gardeners", and secondly, by W.T.Stace who in his book The Philosophy of Hegel suggested that in order to make Kant's structure completely symmetrical a third category would need to be added to the Mathematical and the Dynamical. This, he said, Hegel was to do with his category of concept. |
Force vector Electromagnetic Elastic_force > Fundamental interactions > Electromagnetic Maxwell's equations and the set of techniques built around them adequately describe a wide range of physics involving force in electricity and magnetism. This classical theory already includes relativity effects. Understanding quantized electromagnetic interactions between elementary particles requires quantum electrodynamics (or QED). In QED, photons are fundamental exchange particles, describing all interactions relating to electromagnetism including the electromagnetic force. |
Egalitarian dialogue Summary Egalitarian_dialogue Egalitarian dialogue is a dialogue in which contributions are considered according to the validity of their reasoning, instead of according to the status or position of power of those who make them. Although previously used widely in the social sciences and in reference to the Bakhtinian philosophy of dialogue, it was first systematically applied to dialogical education by Ramón Flecha in his 2000 work Sharing Words. Theory and Practice of Dialogic Learning. |
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