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Grothendieck construction Summary Grothendieck_construction The Grothendieck construction (named after Alexander Grothendieck) is a construction used in the mathematical field of category theory.
Positive feedback In physiology Positive_feedback > Examples and applications > In biology > In physiology A number of examples of positive feedback systems may be found in physiology. One example is the onset of contractions in childbirth, known as the Ferguson reflex. When a contraction occurs, the hormone oxytocin causes a nerve stimulus, which stimulates the hypothalamus to produce more oxytocin, which increases uterine contractions. This results in contractions increasing in amplitude and frequency.
Economic output Summary Economic_output Output in economics is the "quantity (or quality) of goods or services produced in a given time period, by a firm, industry, or country", whether consumed or used for further production. The concept of national output is essential in the field of macroeconomics. It is national output that makes a country rich, not large amounts of money.
National security classification Corporate classification Classified_information > Corporate classification Private corporations often require written confidentiality agreements and conduct background checks on candidates for sensitive positions. In the U.S., the Employee Polygraph Protection Act prohibits private employers from requiring lie detector tests, but there are a few exceptions. Policies dictating methods for marking and safeguarding company-sensitive information (e.g. "IBM Confidential") are common and some companies have more than one level.
Aqua ion Multiple hydrolysis reactions Metal_ions_in_aqueous_solution > Hydrolysis of aqua ions > Multiple hydrolysis reactions 5.4.The overall reaction for the loss of two protons from an aqua ion can be written as z+ - 2 H+⇌ (z-2)+However, the equilibrium constant for the loss of two protons applies equally well to the equilibrium z+ - 2 H+⇌ (z-2)+ + H2Obecause the concentration of water is assumed to be constant. This applies in general: any equilibrium constant is equally valid for a product with an oxide ion as for the product with two hydroxyl ions. The two possibilities can only be distinguished by determining the structure of a salt in the solid state. Oxo bridges tend to occur when the metal oxidation state is high. An example is provided by the molybdenum(IV) complex 4+ in which there is a triangle of molybdenum atoms joined by σ- bonds with an oxide bridge on each edge of the triangle and a fourth oxide which bridges to all three Mo atoms.
Hexadecimal Distinguishing from decimal Intel_hexadecimal_notation > Representation > Written representation > Distinguishing from decimal TI-89 and 92 series uses a 0h prefix: 0h5A3 ALGOL 68 uses the prefix 16r to denote hexadecimal numbers: 16r5a3. Binary, quaternary (base-4) and octal numbers can be specified similarly.
Autoreceptor Summary Autoreceptor Autoreceptors on the presynaptic neuron will also detect this neurotransmitter and often function to control internal cell processes, typically inhibiting further release or synthesis of the neurotransmitter. Thus, release of neurotransmitter is regulated by negative feedback. Autoreceptors are usually G protein-coupled receptors (rather than transmitter-gated ion channels) and act via a second messenger.
Genetic Algorithms Other metaheuristic methods GATTO > Related techniques > Related fields > Other metaheuristic methods Extremal optimization (EO) Unlike GAs, which work with a population of candidate solutions, EO evolves a single solution and makes local modifications to the worst components. This requires that a suitable representation be selected which permits individual solution components to be assigned a quality measure ("fitness"). The governing principle behind this algorithm is that of emergent improvement through selectively removing low-quality components and replacing them with a randomly selected component. This is decidedly at odds with a GA that selects good solutions in an attempt to make better solutions.
Bacteriophage T12 Signs and symptoms Bacteriophage_T12 > Role in pathogenesis > Streptococcal toxic shock syndrome > Signs and symptoms Strep TSS is an acute, febrile illness that begins with a mild viral-like syndrome characterized by fever, chills, myalgia, diarrhea, vomiting and nausea and involves minor soft-tissue infection that may progress to shock, multi-organ failure, and death.
Hooke's Law Spring energy Force_constant > Derived formulae > Spring energy The potential energy Uel(x) stored in a spring is given by which comes from adding up the energy it takes to incrementally compress the spring. That is, the integral of force over displacement. Since the external force has the same general direction as the displacement, the potential energy of a spring is always non-negative.
Optogalvanic effect Introduction Optogalvanic_effect > Introduction In general, light will couple to atomic transitions if the energy difference between atomic levels is in resonance with some of the frequencies of the incoming light, thereby exchanging energy and momentum. In a gas discharge, the gaseous medium is affected by light on resonance with the atoms or molecules in the gas, thus creating a new balance in the energetic properties of the medium. Since the medium consists of charged particles, it is not surprising that also its electrical properties change. == References ==
Quantum phase transition Quantum description Quantum_phase_transitions > Quantum description At nonzero temperatures, classical fluctuations with an energy scale of kBT compete with the quantum fluctuations of energy scale ħω. Here ω is the characteristic frequency of the quantum oscillation and is inversely proportional to the correlation time. Quantum fluctuations dominate the system's behavior in the region where ħω > kBT, known as the quantum critical region.
Gather-scatter (vector addressing) Support Scatter_(vector_addressing) > Support Scatter/gather units were also a part of most vector computers, notably the Cray-1. In this case, the purpose was to efficiently store values in the limited resource of the vector registers. For instance, the Cray-1 had eight 64-word vector registers, so data that contained values that had no effect on the outcome, like zeros in an addition, were using up valuable space that would be better used. By gathering non-zero values into the registers, and scattering the results back out, the registers could be used much more efficiently, leading to higher performance.
Cartesian tree As a binary search tree Cartesian_tree > Applications > As a binary search tree The Cartesian tree of a sorted sequence is just a path graph, rooted at its leftmost endpoint. Binary searching in this tree degenerates to sequential search in the path. However, a different construction uses Cartesian trees to generate binary search trees of logarithmic depth from sorted sequences of values. This can be done by generating priority numbers for each value, and using the sequence of priorities to generate a Cartesian tree.
Synthetic biological circuits Analog tuners Synthetic_biological_circuit > Example circuits > Analog tuners Using negative feedback and identical promoters, linearizer gene circuits can impose uniform gene expression that depends linearly on extracellular chemical inducer concentration.
History of tuberculosis Ancient China History_of_tuberculosis > The East > Ancient China Gradually, after months and years of suffering, this lingering disease brings about death to the sufferer. Afterwards it is transferred to others until the whole family is wiped out."
Class (complexity theory) Computational models Complexity_class > Background > Computational models While other models exist and many complexity classes are defined in terms of them (see section "Other models of computation"), the Turing machine is used to define most basic complexity classes. With the Turing machine, instead of using standard units of time like the second (which make it impossible to disentangle running time from the speed of physical hardware) and standard units of memory like bytes, the notion of time is abstracted as the number of elementary steps that a Turing machine takes to solve a problem and the notion of memory is abstracted as the number of cells that are used on the machine's tape. These are explained in greater detail below. It is also possible to use the Blum axioms to define complexity classes without referring to a concrete computational model, but this approach is less frequently used in complexity theory.
The Entropy Law and the Economic Process Conceptions of scarcity Nicholas_Georgescu-Roegen > Work > Magnum opus on The Entropy Law and the Economic Process > Conceptions of scarcity Georgescu-Roegen's principal argument is that economic scarcity is rooted in physical reality. Introducing the term 'low entropy' for valuable natural resources, and the term 'high entropy' for valueless waste and pollution, Georgescu-Roegen explains that all the economic process does from a physical point of view is to irreversibly transform low entropy into high entropy, thereby providing a flow of natural resources for people to live on. The irreversibility of this economic process is the reason why natural resources are scarce: Recycling of material resources is possible, but only by using up some energy resources plus an additional amount of other material resources; and energy resources, in turn, cannot be recycled at all, but are dissipated as waste heat (according to the entropy law). : 277–282 Georgescu-Roegen points out that the earth is a closed system in the thermodynamic sense of the term: the earth exchanges energy, but not matter (practically) with the rest of the universe.
Radioisotope thermoelectric generators 90Sr Radioisotope_Thermoelectric_Generator > Fuels > 90Sr 90Sr has a high fission product yield in the fission of both 235U and 239Pu and is thus available in large quantities at a relatively low price if extracted from spent nuclear fuel. As 90Sr is a very reactive alkaline earth metal and a so-called "bone seeker" that accumulates in bone-tissue due to its chemical similarity to calcium (once in the bones it can significantly damage the bone marrow, a rapidly dividing tissue), it is usually not employed in pure form in RTGs. The most common form is the perovskite Strontium titanate (SrTiO3) which is chemically nigh-inert and has a high melting point.
Apache Pivot Architecture Apache_Pivot > Architecture Its classes are divided in the following categories: Core classes that enable the classes in the other categories to function WTK classes that provide user interface elements such as buttons and lists. These are built according to the model-view-controller architecture. Most of Pivot's classes are included in the WTK category. Web classes that enable communication with remote computers Charts that allow the software engineer to build interactive charts Tools that provide utility functionality
Q&A software Social and information structure Q&A_software > Mechanisms > Social and information structure A graph connecting topics to users, a social graph connecting users, and a graph connecting related questions. These connections help users find the topic that they are looking for and build a social connection with people sharing the same interests. Also, as contributors gather according to a common theme, their votes help to screen out the domain expert and the high quality questions in that field. The heterogeneity in the user and question graphs are significant contributors to the quality of the community's knowledge base.
Isotope affinity tags Metabolic flux analysis using stable isotope labeling Radioisotopic_labeling > Stable isotope labeling > Metabolic flux analysis using stable isotope labeling Other proportions can occur depending on how much of the original metabolite follows the left side of the pathway versus the right side of the pathway. Here the proportions are shown for a situation in which half of the metabolites take the left side and half the right, but other proportions can occur. These patterns of labeled atoms and unlabeled atoms in one compound represent isotopomers.
EXR color filter array Fujifilm "EXR" color filter array EXR_color_filter_array > Modifications > Fujifilm "EXR" color filter array The main reason for this type of array is to contribute to pixel "binning", where two adjacent photosites can be merged, making the sensor itself more "sensitive" to light. Another reason is for the sensor to record two different exposures, which is then merged to produce an image with greater dynamic range. The underlying circuitry has two read-out channels that take their information from alternate rows of the sensor.
Centrality Percolation centrality Closeness_(graph_theory) > Percolation centrality In all of these scenarios, a ‘contagion’ spreads over the links of a complex network, altering the ‘states’ of the nodes as it spreads, either recoverably or otherwise. For example, in an epidemiological scenario, individuals go from ‘susceptible’ to ‘infected’ state as the infection spreads. The states the individual nodes can take in the above examples could be binary (such as received/not received a piece of news), discrete (susceptible/infected/recovered), or even continuous (such as the proportion of infected people in a town), as the contagion spreads.
Function series Summary Function_series In calculus, a function series is a series, where the summands are not just real or complex numbers but functions.
Interference freedom Dijkstra's Principle of non-interference Interference_freedom > Dijkstra's Principle of non-interference Edsger W. Dijkstra introduced the principle of non-interference in EWD 117, "Programming Considered as a Human Activity", written about 1965. This principle states that: The correctness of the whole can be established by taking into account only the exterior specifications (abbreviated specs throughout) of the parts, and not their interior construction. Dijkstra outlined the general steps in using this principle: Give a complete spec of each individual part. Check that the total problem is solved when program parts meeting their specs are available.
Dollar auction Analysis Dollar_auction > Analysis When a player is behind, they are indifferent between raising and dropping out. If the opponent drops out with probability p {\displaystyle p} , raising gives the player an expected payoff of p × 1 + ( 1 − p ) × 0 − 0.05. {\displaystyle p\times 1+(1-p)\times 0-0.05.}
Infinitesimal Calculus Foundations Infinitesimal_Calculus > History > Foundations Laurent Schwartz introduced distributions, which can be used to take the derivative of any function whatsoever.Limits are not the only rigorous approach to the foundation of calculus. Another way is to use Abraham Robinson's non-standard analysis. Robinson's approach, developed in the 1960s, uses technical machinery from mathematical logic to augment the real number system with infinitesimal and infinite numbers, as in the original Newton-Leibniz conception.
Landau–Zener transition Multistate problem Landau–Zener_formula > Multistate problem A surprising fact about the solution of this model is coincidence of the exactly obtained transition probability matrix with its form obtained with a simple semiclassical independent crossing approximation. With some generalizations, this property appears in almost all solvable Landau–Zener systems with a finite number of interacting states. Generalized bow-tie model.
Epicentral distance S-P time difference method Epicentral_distance > Measuring method > S-P time difference method Even if the depth of focus of an earthquake is very deep, it can still have a very short epicentral distance. When measuring the epicentral distance of an earthquake with a small epicentral distance, first measure the reading of the initial motion of P wave, and then confirm the arrival of S wave. The value of the epicenter distance Δ is found on the travel timetable according to the arrival time difference between the P wave and S wave.
Endocrine gland Pituitary gland Endocrine_gland > Pituitary gland Most anterior pituitary hormones exhibit a diurnal rhythm of release, which is subject to modification by stimuli influencing the hypothalamus. Somatotropic hormone or growth hormone (GH) is an anabolic hormone that stimulates the growth of all body tissues especially skeletal muscle and bone. It may act directly, or indirectly via insulin-like growth factors (IGFs).
Lisp (programming language) Major dialects Lisp_(programming_language) > Major dialects It has many of the features of Lisp Machine Lisp (a large Lisp dialect used to program Lisp Machines), but was designed to be efficiently implementable on any personal computer or workstation. Common Lisp is a general-purpose programming language and thus has a large language standard including many built-in data types, functions, macros and other language elements, and an object system (Common Lisp Object System). Common Lisp also borrowed certain features from Scheme such as lexical scoping and lexical closures.
Unit hyperbola Summary Unit_hyperbola There the asymptotes of the unit hyperbola form a light cone. Further, the attention to areas of hyperbolic sectors by Gregoire de Saint-Vincent led to the logarithm function and the modern parametrization of the hyperbola by sector areas. When the notions of conjugate hyperbolas and hyperbolic angles are understood, then the classical complex numbers, which are built around the unit circle, can be replaced with numbers built around the unit hyperbola.
Supersymmetry The supersymmetry algebra Supersymmetric_theory > Applications > Extension of possible symmetry groups > The supersymmetry algebra Traditional symmetries of physics are generated by objects that transform by the tensor representations of the Poincaré group and internal symmetries. Supersymmetries, however, are generated by objects that transform by the spin representations. According to the spin-statistics theorem, bosonic fields commute while fermionic fields anticommute. Combining the two kinds of fields into a single algebra requires the introduction of a Z2-grading under which the bosons are the even elements and the fermions are the odd elements.
Noise Reduction Coefficient Summary Noise_Reduction_Coefficient The noise reduction coefficient (commonly abbreviated NRC) is a single number value ranging from 0.0 to 1.0 that describes the average sound absorption performance of a material. An NRC of 0.0 indicates the object does not attenuate mid-frequency sounds, but rather reflects sound energy. This is more conceptual than physically achievable: even very thick concrete walls will attenuate sound and may have an NRC of 0.05.
Fatty-acid metabolism Fatty acid catabolism Fatty_acid_metabolism > Fatty acid catabolism The occurrence of high levels of ketones in the blood during starvation, a low carbohydrate diet, prolonged heavy exercise, or uncontrolled type 1 diabetes mellitus is known as ketosis, and, in its extreme form, in out-of-control type 1 diabetes mellitus, as ketoacidosis. The glycerol released by lipase action is phosphorylated by glycerol kinase in the liver (the only tissue in which this reaction can occur), and the resulting glycerol 3-phosphate is oxidized to dihydroxyacetone phosphate. The glycolytic enzyme triose phosphate isomerase converts this compound to glyceraldehyde 3-phosphate, which is oxidized via glycolysis, or converted to glucose via gluconeogenesis.
Staggered fermion Simulating staggered fermions Staggered_fermion > Simulating staggered fermions Since simulations are done using the single-component action, simulating staggered fermions is very fast as this requires simulating only single-component Grassmann variables rather than four component spinors. The main code and gauge ensembles used for staggered fermions comes from the MILC collaboration.An advantage of staggered fermions over some other lattice fermions in that the remnant chiral symmetry protects simulations from exceptional configurations, which are gauge field configurations that lead to small eigenvalues of the Dirac operator, making numerical inversion difficult.
Diploid cell Zygoidy and azygoidy Ploidy > Types of ploidy > Zygoidy and azygoidy It may be the natural state of some asexual species or may occur after meiosis. In diploid organisms the azygoid state is monoploid. (See below for dihaploidy.)
Base (chemical) Summary Chemical_base If the aqueous solution is saturated with a given salt solute, any additional such salt precipitates out of the solution. In the more general Brønsted–Lowry acid–base theory (1923), a base is a substance that can accept hydrogen cations (H+)—otherwise known as protons. This does include aqueous hydroxides since OH− does react with H+ to form water, so that Arrhenius bases are a subset of Brønsted bases.
Second principle of thermodynamics Planck's proposition Second_principle_of_thermodynamics > Various statements of the law > Planck's proposition Planck offered the following proposition as derived directly from experience. This is sometimes regarded as his statement of the second law, but he regarded it as a starting point for the derivation of the second law. It is impossible to construct an engine which will work in a complete cycle, and produce no effect except the raising of a weight and cooling of a heat reservoir.
Lester Allan Pelton Inventing the Pelton wheel Lester_Allan_Pelton > Inventing the Pelton wheel Pelton's ideas for improving the turbine water wheel came from his studies of mining equipment and operations in California's gold rush country. Summary descriptions of the local technology observed by Pelton, and of the science by which his turbine water wheel extracts kinetic energy from a coursing mountain stream follow... Steam-heat powered much of local mining activities but required a lot of wood for fuel; nearby forests were routinely decimated. Turbine water wheels also were used to supply power, but these were inefficient in converting the kinetic energy of mountain streams to horsepower. D.P.
Hybrid sterility Post-copulation or fertilization mechanisms in animals Isolating_mechanisms > Genetics > Post-copulation or fertilization mechanisms in animals The Hmr gene, linked to the X chromosome and implicated in the viability of male hybrids between D. melanogaster and D. simulans, is a gene from the proto-oncogene family myb, that codes for a transcriptional regulator. Two variants of this gene function perfectly well in each separate species, but in the hybrid they do not function correctly, possibly due to the different genetic background of each species. Examination of the allele sequence of the two species shows that change of direction substitutions are more abundant than synonymous substitutions, suggesting that this gene has been subject to intense natural selection.The Dobzhansky–Muller model proposes that reproductive incompatibilities between species are caused by the interaction of the genes of the respective species.
List of textbooks on classical mechanics and quantum mechanics Quantum mechanics List_of_textbooks_on_classical_mechanics_and_quantum_mechanics > Undergraduate > Quantum mechanics 3 (2nd ed.). Addison-Wesley. ISBN 978-0-8053-9065-0.
Tuberculosis diagnosis Mantoux skin test Tuberculosis_diagnosis > Immunological test > Mantoux skin test The Mantoux skin test is used in the United States and is endorsed by the American Thoracic Society and Centers for Disease Control and Prevention (CDC).If a person has had a history of a positive tuberculin skin test, another skin test is not needed.
Banded Iron Formation Formation processes Banded_iron_formations > Origins > Formation processes Another theory is that mesobands are primary structures resulting from pulses of activity along mid-ocean ridges that change the availability of reduced iron on time scales of decades. In the case of granular iron formations, the mesobands are attributed to winnowing of sediments in shallow water, in which wave action tended to segregate particles of different size and composition.For banded iron formations to be deposited, several preconditions must be met. The deposition basin must contain waters that are ferruginous (rich in iron).
Real Analysis Sequences Real_Analysis > Scope > Sequences A sequence is a function whose domain is a countable, totally ordered set. The domain is usually taken to be the natural numbers, although it is occasionally convenient to also consider bidirectional sequences indexed by the set of all integers, including negative indices. Of interest in real analysis, a real-valued sequence, here indexed by the natural numbers, is a map a: N → R: n ↦ a n {\displaystyle a:\mathbb {N} \to \mathbb {R} :n\mapsto a_{n}} .
Computational Fluid Dynamics Hierarchy of fluid flow equations Computational_fluid_mechanics > Hierarchy of fluid flow equations Assume that density variations are always and everywhere negligible except in the gravity term of the momentum-conservation equation (where density multiplies the gravitational acceleration). Also assume that various fluid properties such as viscosity, thermal conductivity, and heat capacity are always and everywhere constant. The Boussinesq equations are widely used in microscale meteorology.
Factorial Related sequences and functions Factorial > Related sequences and functions . That is, For example, 9!! = 1 × 3 × 5 × 7 × 9 = 945.
Robert Parr Achievements and awards Robert_Parr > Achievements and awards Working with DuPont chemist Rudolph Pariser, Parr developed a method of computing approximate molecular orbitals for pi electron systems, published in 1953. Since an identical procedure was derived by John A. Pople the same year, it is generally referred to as the Pariser–Parr–Pople method or PPP method. The PPP method differed from existing structural chemistry thinking (which advocated maximum overlap principle) by advancing the concept of zero differential overlap approximation. By 1978 Parr had realized that density functional theory (DFT) would be extremely useful in quantitative calculations of chemical and biological systems, especially those with high molecular weights.
Modified Newtonian Dynamics Overview Modified_Newtonian_Dynamics > Overview Alternatively, Milgrom's law can be viewed as leaving Newton's Second Law intact and instead modifying the inverse-square law of gravity, so that the true gravitational force on an object of mass m due to another of mass M is roughly of the form G M m μ ( a a 0 ) r 2 . {\textstyle {\frac {GMm}{\mu \left({\frac {a}{a_{0}}}\right)r^{2}}}.} In this interpretation, Milgrom's modification would apply exclusively to gravitational phenomena.By itself, Milgrom's law is not a complete and self-contained physical theory, but rather an ad hoc empirically motivated variant of one of the several equations that constitute classical mechanics.
Computer processor Summary Processor_(computing) However, it can also refer to other coprocessors, such as a graphics processing unit (GPU).Traditional processors are typically based on silicon; however, researchers have developed experimental processors based on alternative materials such as carbon nanotubes, graphene, diamond, and alloys made of elements from groups three and five of the periodic table. Transistors made of a single sheet of silicon atoms one atom tall and other 2D materials have been researched for use in processors. Quantum processors have been created; they use quantum superposition to represent bits (called qubits) instead of only an on or off state.
Belief-Desire-Intention software model 'Pure' BDI Belief–desire–intention_software_model > BDI agent implementations > 'Pure' BDI Procedural Reasoning System (PRS) IRMA (not implemented but can be considered as PRS with non-reconsideration) UM-PRS OpenPRS Distributed Multi-Agent Reasoning System (dMARS) AgentSpeak(L) – see Jason below AgentSpeak(RT) Agent Real-Time System (ARTS) (ARTS) JAM JACK Intelligent Agents JADEX (open source project) JASON GORITE SPARK 3APL 2APL GOAL agent programming language CogniTAO (Think-As-One) Living Systems Process Suite PROFETA Gwendolen (Part of the Model Checking Agent Programming Languages Framework)
Causal Inference General Causal_Inference > Methodology > General Most of the efforts in causal inference are in the attempt to replicate experimental conditions. Epidemiological studies employ different epidemiological methods of collecting and measuring evidence of risk factors and effect and different ways of measuring association between the two. Results of a 2020 review of methods for causal inference found that using existing literature for clinical training programs can be challenging. This is because published articles often assume an advanced technical background, they may be written from multiple statistical, epidemiological, computer science, or philosophical perspectives, methodological approaches continue to expand rapidly, and many aspects of causal inference receive limited coverage.Common frameworks for causal inference include the causal pie model (component-cause), Pearl's structural causal model (causal diagram + do-calculus), structural equation modeling, and Rubin causal model (potential-outcome), which are often used in areas such as social sciences and epidemiology.
Gravitation (book) Summary Gravitation_(book) The book contains 10 parts and 44 chapters, each beginning with a quotation. The bibliography has a long list of original sources and other notable books in the field. While this may not be considered the best introductory text because its coverage may overwhelm a newcomer, and even though parts of it are now out of date, it remains a highly valued reference for advanced graduate students and researchers.
Occupational Safety and Health Administration Enforcement Occupational_Safety_and_Health_Administration > Enforcement In determining the amount of the proposed penalty, OSHA must take into account the gravity of the alleged violation and the employer’s size of business, good faith, and history of previous violations. Employers have the right to contest any part of the citation, including whether a violation actually exists. Workers only have the right to challenge the deadline by which a problem must be resolved.
Volume of revolution Summary Solid_of_revolution In geometry, a solid of revolution is a solid figure obtained by rotating a plane figure around some straight line (the axis of revolution), which may not intersect the generatrix (except at its boundary). The surface created by this revolution and which bounds the solid is the surface of revolution. Assuming that the curve does not cross the axis, the solid's volume is equal to the length of the circle described by the figure's centroid multiplied by the figure's area (Pappus's second centroid theorem). A representative disc is a three-dimensional volume element of a solid of revolution. The element is created by rotating a line segment (of length w) around some axis (located r units away), so that a cylindrical volume of πr2w units is enclosed.
African Society for Bioinformatics and Computational Biology Objectives African_Society_for_Bioinformatics_and_Computational_Biology > Objectives Identify, promote and establish opportunities for networking. Encourage and develop bioinformatics and computational biology nodes. Increase awareness and promote the use of bioinformatics and computational biology. Facilitate access to bioinformatics and computational biology infrastructure. Promote bioinformatics and computational biology education.The Society also has good cooperation with the newly re-established African BIOinformatics NETwork (ABioNet). The ABioNET is in the process of development of a programme of training and research linking key sites of African Bioinformatics to provide regional capacity development.
Dimensional stability (fabric) Significance Dimensional_stability_(fabric) > Significance The dimensional stability of textile materials is an important quality parameter. Failing and unstable materials can cause deforming of the garments or products. Shrinkage is tested at various stages, but most importantly before cutting the fabric into further sewn products and after cutting and sewing prior to supplying the products to buyers and consumers. It is a required parameter of quality control to ensure the sizes of the products to avoid any complaints regarding deformation or change in dimensions after domestic laundry.
In Situ Oxidation Ozone In_Situ_Oxidation > Agents of Oxidization > Ozone While oxygen is a very strong oxidant, its elemental form O2 is not very soluble in water. This poses a problem in ground water remediation, because the chemical must be able to mix with water to remove the contaminant. Fortunately, ozone (O3) is about 12 times more soluble than O2 and, although it is still comparably insoluble, it is a strong oxidant.The unique part of ozone oxidation is its in-situ application. Because, unlike other oxidants used in ISCO, it is a gas, it needs to be injected into the contamination site from the bottom rather than the top.
Quasi-experimental design Advantages Quasi-experimental_design > Advantages Also, this experimentation method is efficient in longitudinal research that involves longer time periods which can be followed up in different environments. Other advantages of quasi experiments include the idea of having any manipulations the experimenter so chooses. In natural experiments, the researchers have to let manipulations occur on their own and have no control over them whatsoever. Also, using self selected groups in quasi experiments also takes away the chance of ethical, conditional, etc. concerns while conducting the study.
Large-conductance mechanosensitive channel Biological role Large-conductance_mechanosensitive_channel > Biological role Physical impacts or vibrations, though crucial for animals, have little effect on microbes such as E. coli. In comparison, osmotic force greatly affects individual cells or microbes within their aquatic environment. When bacteria is under osmotic downshock, which is during the transition from media of high osmolarity to low, water inflow gives rise to a substantial increase in the turgor pressure, which is capable of bursting the cell envelope. Mechanosensitive channels are major pathways for the release of cytoplasmic solutes to achieve a rapid reduction of the turgor pressure, therefore avoiding lysis.
Acute respiratory distress syndrome Prognosis Acute_respiratory_distress_syndrome > Prognosis The overall prognosis of ARDS is poor, with mortality rates of approximately 40%. Exercise limitation, physical and psychological sequelae, decreased physical quality of life, and increased costs and use of health care services are important sequelae of ARDS.
Serotonin-norepinephrine reuptake inhibitor Indications Serotonin–norepinephrine_reuptake_inhibitors > Indications SNRIs have been tested for treatment of the following conditions: Major depressive disorder (MDD) Posttraumatic stress disorder (PTSD) Generalized anxiety disorder (GAD) Social anxiety disorder (SAD) Obsessive compulsive disorder Panic disorder Neuropathic pain Fibromyalgia Chronic musculoskeletal pain
Switch mode power supply Transformer design Switch-mode_power_supply > Transformer design Any switched-mode power supply that gets its power from an AC power line (called an "off-line" converter) requires a transformer for galvanic isolation. Some DC-to-DC converters may also include a transformer, although isolation may not be critical in these cases. SMPS transformers run at high frequencies. Most of the cost savings (and space savings) in off-line power supplies result from the smaller size of the high-frequency transformer compared to the 50/60 Hz transformers formerly used.
Elevation view CGI and computer-aided design Architectural_drafting > Drafting > CGI and computer-aided design Errors can be deleted, and the speed of drafting allows many permutations to be tried before the design is finalized. On the other hand, CAD drawing encourages a proliferation of detail and increased expectations of accuracy, aspects which reduce the efficiency originally expected from the move to computerization. Professional CAD software such as AutoCAD is complex and requires both training and experience before the operator becomes fully productive.
Machine ethics Algorithms and training Machine_ethics > Focuses of machine ethics > Algorithms and training AI paradigms have been debated over, especially in relation to their efficacy and bias. Nick Bostrom and Eliezer Yudkowsky have argued for decision trees (such as ID3) over neural networks and genetic algorithms on the grounds that decision trees obey modern social norms of transparency and predictability (e.g. stare decisis). In contrast, Chris Santos-Lang argued in favor of neural networks and genetic algorithms on the grounds that the norms of any age must be allowed to change and that natural failure to fully satisfy these particular norms has been essential in making humans less vulnerable than machines to criminal "hackers".In 2009, in an experiment at the Laboratory of Intelligent Systems in the Ecole Polytechnique Fédérale of Lausanne in Switzerland, AI robots were programmed to cooperate with each other and tasked with the goal of searching for a beneficial resource while avoiding a poisonous resource. During the experiment, the robots were grouped into clans, and the successful members' digital genetic code was used for the next generation, a type of algorithm known as a genetic algorithm.
History of probability Eighteenth century History_of_probability > Eighteenth century Jacob Bernoulli's Ars Conjectandi (posthumous, 1713) and Abraham De Moivre's The Doctrine of Chances (1718) put probability on a sound mathematical footing, showing how to calculate a wide range of complex probabilities. Bernoulli proved a version of the fundamental law of large numbers, which states that in a large number of trials, the average of the outcomes is likely to be very close to the expected value - for example, in 1000 throws of a fair coin, it is likely that there are close to 500 heads (and the larger the number of throws, the closer to half-and-half the proportion is likely to be).
HOXA9 Potential in Ovarian Cancer HOXA9 > Clinical significance > Pure erythroid leukemia > Potential in Ovarian Cancer HOXA9 has also been used as a potential biomarker for ovarian cancer. Because the homebox family of genes plays an essential role in development and differentiation, it is common to see malformations in these crucial genes often linked to malignancy (Faaborg et al., 2021). About 70%-80% of all deaths from epithelial ovarian cancer are associated with high-grade serous ovarian cancer (Li et al., 2022). HOXA9 genes are responsible for the patterning of the Mullerian system in females and often found in the fallopian tubes, however, it has been found to be methylated in ovarian tissues (Faaborg et al., 2021).
Vampire number Summary Vampire_number In number theory, a vampire number (or true vampire number) is a composite natural number with an even number of digits, that can be factored into two natural numbers each with half as many digits as the original number, where the two factors contain precisely all the digits of the original number, in any order, counting multiplicity. The two factors cannot both have trailing zeroes. The first vampire number is 1260 = 21 × 60.
Accessibility apps Discriminative aspects of technology Accessibility_apps > Discriminative aspects of technology Additionally, there is a form of technology that allows people who have diabetes to monitor their blood glucose and administers insulin when required. However, this same technology poses a threat to individuals because it enables a platform for cybercrime where abuse, exploitation, intimidation and threatening conduct becomes possible.New technology poses a threat to the right to non-discrimination and equal treatment. Economic inequality can become apparent when a particular labor force is replaced by robotics.
Experimental reactor Technical aspects Research_reactors > Technical aspects Research reactors are simpler than power reactors and operate at lower temperatures. They need far less fuel, and far less fission products build up as the fuel is used. On the other hand, their fuel requires more highly enriched uranium, typically up to 20% U-235, although some use 93% U-235; while 20% enrichment is not generally considered usable in nuclear weapons, 93% is commonly referred to as "weapons-grade". They also have a very high power density in the core, which requires special design features. Like power reactors, the core needs cooling, typically natural or forced convection with water, and a moderator is required to slow the neutron velocities and enhance fission. As neutron production is their main function, most research reactors benefit from reflectors to reduce neutron loss from the core.
Generative topographic map Details of the algorithm Generative_topographic_map > Details of the algorithm The approach is strongly related to density networks which use importance sampling and a multi-layer perceptron to form a non-linear latent variable model. In the GTM the latent space is a discrete grid of points which is assumed to be non-linearly projected into data space. A Gaussian noise assumption is then made in data space so that the model becomes a constrained mixture of Gaussians. Then the model's likelihood can be maximized by EM.
Central nervous system stimulant Mechanisms of action Central_nervous_system_stimulant > Mechanisms of action Some stimulants, such as some amphetamine derivatives and, notably, yohimbine, can decrease negative feedback by antagonizing regulatory autoreceptors. Adrenergic agonists, such as, in part, ephedrine, act by directly binding to and activating adrenergic receptors, producing sympathomimetic effects.
Complete orthonormal basis Summary Complete_orthogonal_system {\displaystyle V.} Under these coordinates, the inner product becomes a dot product of vectors. Thus the presence of an orthonormal basis reduces the study of a finite-dimensional inner product space to the study of R n {\displaystyle \mathbb {R} ^{n}} under dot product.
Steel arch bridge Function Steel_arch_bridge > Function The use of a through arch does not change the proportions or size of the arch: a large span will still require a tall arch, although this can now reach any height above the deck without obstructing traffic. The arch may also reach downwards at its sides, to either reach strong foundations or to place the roadway at a convenient height for spanning a deep valley from a plateau above. The Tyne Bridge demonstrates both of these advantages.
Fractionation of carbon isotopes in oxygenic photosynthesis Photosynthesis reactions Fractionation_of_carbon_isotopes_in_oxygenic_photosynthesis > Photosynthesis reactions The chemical pathway of oxygenic photosynthesis fixes carbon in two stages: the light-dependent reactions and the light-independent reactions. The light-dependent reactions capture light energy to transfer electrons from water and convert NADP+, ADP, and inorganic phosphate into the energy-storage molecules NADPH and ATP. The overall equation for the light-dependent reactions is generally:2 H2O + 2 NADP+ + 3 ADP + 3 Pi + light → 2 NADPH + 2 H+ + 3 ATP + O2The light-independent reactions undergo the Calvin-Benson cycle, in which the energy from NADPH and ATP is used to convert carbon dioxide and water into organic compounds via the enzyme RuBisCO. The overall general equation for the light-independent reactions is the following:3 CO2 + 9 ATP + 6 NADPH + 6 H+ → C3H6O3-phosphate + 9 ADP + 8 Pi + 6 NADP+ + 3 H2OThe 3-carbon products (C3H6O3-phosphate) of the Calvin cycle are later converted to glucose or other carbohydrates such as starch, sucrose, and cellulose.
Advanced electronic signature Vision Advanced_electronic_signature > Vision The implementation of advanced electronic signatures under the specification of eIDAS serves several purposes. Business and public services processes, even those that go across borders can be safely expedited by using electronic signing. With eIDAS, EU States are required to establish “points of single contact” (PSCs) for trust services that ensure the electronic ID schemes can be used in public sector transactions that occur cross-borders, including access to healthcare information across borders.In the past, when signing a document or message, the signatory would sign it and then return it to its intended recipient through the postal service, via facsimile service, or by scanning and attaching it to an email. This could lead to delays and of course, the possibility that signatures could be forged and documents altered, especially when multiple signatures from different people located in different locations are required. The process of using an advanced electronic signature saves time, is legally binding and assures a high level of technical security.
Blind signature Summary Blind_signature In cryptography a blind signature, as introduced by David Chaum, is a form of digital signature in which the content of a message is disguised (blinded) before it is signed. The resulting blind signature can be publicly verified against the original, unblinded message in the manner of a regular digital signature. Blind signatures are typically employed in privacy-related protocols where the signer and message author are different parties. Examples include cryptographic election systems and digital cash schemes.
Regression model Prediction (interpolation and extrapolation) Regression_analysis > Prediction (interpolation and extrapolation) The further the extrapolation goes outside the data, the more room there is for the model to fail due to differences between the assumptions and the sample data or the true values. It is generally advised that when performing extrapolation, one should accompany the estimated value of the dependent variable with a prediction interval that represents the uncertainty. Such intervals tend to expand rapidly as the values of the independent variable(s) moved outside the range covered by the observed data.
Cartan connection Motivation Cartan_connection > Introduction > Motivation Another example is obtained by replacing the planes, as model surfaces, by spheres, which are homogeneous under the Möbius group of conformal transformations. There is no longer a unique sphere tangent to a smooth surface S at each point, since the radius of the sphere is undetermined. This can be fixed by supposing that the sphere has the same mean curvature as S at the point of contact.
Killer activation receptors Physiology Killer_activation_receptor > Physiology To recapitulate, these ligands activate the NK, as we explained. However, before the activation, Killer Inhibition Receptors (KIRs) recognize certain molecules in the MHC class I of the hosted cell and get engaged with them. These molecules are typical of healthy cells but some of these molecules are repressed in infected or transformed cells.
Capacitor Motor starters Parallel-plate_capacitor > Applications > Motor starters When the rotor comes close to operating speed, a centrifugal switch (or current-sensitive relay in series with the main winding) disconnects the capacitor. The start capacitor is typically mounted to the side of the motor housing. These are called capacitor-start motors, that have relatively high starting torque.
Glossary of chemistry terms C Glossary_of_chemistry_terms > C cooling curve coordinate chemistry coordinate covalent bond See dipolar bond. coordination complex A chemical compound consisting of a central atom or ion, usually metallic and known as the coordination center, bonded to a surrounding array of other groups of atoms, e.g. molecules or ions, which are known as ligands or complexing agents. Many metal-containing compounds, especially those of the transition metals, are coordination complexes.
Osmometer Summary Osmometer Membrane osmometers measure the osmotic pressure of a solution separated from pure solvent by a semipermeable membrane.Osmometers are useful for determining the total concentration of dissolved salts and sugars in blood or urine samples. Osmometry is also useful in determining the molecular weight of unknown compounds and polymers. Osmometry is the measurement of the osmotic strength of a substance. This is often used by chemists for the determination of average molecular weight. Osmometry is also useful for estimating the drought tolerance of plant leaves.
DNA synthesis Gene synthesis DNA_synthesis > Gene synthesis Artificial gene synthesis is the process of synthesizing a gene in vitro without the need for initial template DNA samples. In 2010 J. Craig Venter and his team were the first to use entirely synthesized DNA to create a self-replicating microbe, dubbed Mycoplasma laboratorium.
Polycarbonyl Summary Polycarbonyl Polycarbonyl, (also known as polymeric-CO, p-CO or poly-CO) is a solid, metastable, and explosive polymer of carbon monoxide. The polymer is produced by exposing carbon monoxide to high pressures. The structure of the solid appears amorphous, but may include a zig zag of equally-spaced CO groups.
Antitubercular agents Treatment failure Drug-resistant_tuberculosis > Treatment failure Patients who fail treatment must be distinguished from patients who relapse. Patients who responded to treatment and appeared to be cured after completing a course of TB treatment are not classed as treatment failures, but as relapses and are discussed in a separate section below. Patients are said to have failed treatment if they fail to respond to treatment (cough and sputum production persisting throughout the whole of treatment), or only experience a transient response to treatment (the patient gets better at first, but then get worse again, all the while on treatment).It is very uncommon for patients not to respond to TB treatment at all (even transiently), because this implies resistance at base-line to all of the drugs in the regimen. Patients who fail to get any response at all while on treatment should first of all be questioned very closely about whether or not they have been taking their medicines, and perhaps even be admitted to hospital to be observed taking their treatment.
Light pressure Radiation pressure by emission Light_pressure > Theory > Radiation pressure by emission Just as a wave reflected from a body contributes to the net radiation pressure experienced, a body that emits radiation of its own (rather than reflected) obtains a radiation pressure again given by the irradiance of that emission in the direction normal to the surface Ie: The emission can be from black-body radiation or any other radiative mechanism. Since all materials emit black-body radiation (unless they are totally reflective or at absolute zero), this source for radiation pressure is ubiquitous but usually tiny. However, because black-body radiation increases rapidly with temperature (as the fourth power of temperature, given by the Stefan–Boltzmann law), radiation pressure due to the temperature of a very hot object (or due to incoming black-body radiation from similarly hot surroundings) can become significant. This is important in stellar interiors.
Fire history Tree-ring data Fire_history > Tree-ring data The growth record of a tree in seasonal climates is preserved in the growth rings in the stem wood; the field of dendrochronology is the study of the record of climate and other events preserved in the growth record. Each growth ring represents one year of life. The thickness of each ring indicates the amount of wood produced during that growing season. At the beginning of the growing season large cells are able to quickly divide creating a light colored wood.
Ozone layer depletion Location of hole Ozone_depleting > Misconceptions > Location of hole Some people thought that the ozone hole should be above the sources of CFCs. However, CFCs are well mixed globally in the troposphere and stratosphere. The reason for occurrence of the ozone hole above Antarctica is not because there are more CFCs concentrated but because the low temperatures help form polar stratospheric clouds. In fact, there are findings of significant and localized "ozone holes" above other parts of the earth, like above Central Asia.
Tensor order Summary Tensor In mathematics, a tensor is an algebraic object that describes a multilinear relationship between sets of algebraic objects related to a vector space. Tensors may map between different objects such as vectors, scalars, and even other tensors. There are many types of tensors, including scalars and vectors (which are the simplest tensors), dual vectors, multilinear maps between vector spaces, and even some operations such as the dot product. Tensors are defined independent of any basis, although they are often referred to by their components in a basis related to a particular coordinate system; those components form an array, which can be thought of as a high-dimensional matrix.
Loss of function By impact on protein sequence Sporadic_mutation > Classification of types > By impact on protein sequence (There can also be silent mutations in nucleotides outside of the coding regions, such as the introns, because the exact nucleotide sequence is not as crucial as it is in the coding regions, but these are not considered synonymous substitutions.) A nonsynonymous substitution replaces a codon with another codon that codes for a different amino acid, so that the produced amino acid sequence is modified. Nonsynonymous substitutions can be classified as nonsense or missense mutations: A missense mutation changes a nucleotide to cause substitution of a different amino acid.
User-defined function Summary User-defined_function A user-defined function (UDF) is a function provided by the user of a program or environment, in a context where the usual assumption is that functions are built into the program or environment. UDFs are usually written for the requirement of its creator.
Justice as Fairness Fair equality of opportunity Difference_Principle > Second principle: the equality principle > Fair equality of opportunity This principle maintains that "offices and positions" have to be open to all, regardless of their social background, caste or gender. This principle is stronger than "formal equality of opportunity." Rawls argues that human potential should not only be a "right," but also an "effective" equal opportunity.
Chemical graph generator Symmetry groups for molecular graphs Chemical_graph_generator > Mathematical basis > Symmetry groups for molecular graphs For a set of elements, a permutation is a rearrangement of these elements. An example is given below: The second line of this table shows a permutation of the first line. The multiplication of permutations, a {\displaystyle a} and b {\displaystyle b} , is defined as a function composition, as shown below. The combination of two permutations is also a permutation.
Triangle geometry Points, lines, and circles associated with a triangle Triangle_(geometry) > Points, lines, and circles associated with a triangle The circumcircle's radius is called the "circumradius". Thales' theorem implies that if the circumcenter is located on a side of the triangle, then the opposite angle is a right one. If the circumcenter is located inside the triangle, then the triangle is acute; if the circumcenter is located outside the triangle, then the triangle is obtuse.
Traction bronchiectasis Anti-inflammatories Traction_bronchiectasis > Management > Anti-inflammatories Long term use of high-dose inhaled corticosteroids can lead to adverse consequences such as cataracts and osteoporosis. It is not recommended for routine use in children. One commonly used therapy is beclometasone dipropionate.
Open mapping theorem (complex analysis) Proof Open_mapping_theorem_(complex_analysis) > Proof The image of the ball B, f(B) is a subset of the image of U, f(U). Thus w0 is an interior point of f(U). Since w0 was arbitrary in f(U) we know that f(U) is open. Since U was arbitrary, the function f is open.
Multi-paradigm programming language Summary Multi-paradigm_programming_language Programming paradigms are a way to classify programming languages based on their features. Languages can be classified into multiple paradigms. Some paradigms are concerned mainly with implications for the execution model of the language, such as allowing side effects, or whether the sequence of operations is defined by the execution model. Other paradigms are concerned mainly with the way that code is organized, such as grouping a code into units along with the state that is modified by the code.
Social affordance Summary Social_affordance These social interactions include users’ responses, social accessibility and society related changes. Social affordances are not synonymous with mere factual, statistical frequency; on the contrary, the social normality of primitive forms of coordination can become normative, even in primate societies. A good example clarifies social affordance as follows: “ A wooden bench is supposed to have a sit affordance.

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