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Swamp wallaby Reproduction Swamp_wallaby > Reproduction This timing makes it possible for swamp wallaby females to overlap two pregnancies, gestating both an embryo and a fetus at the same time. The swamp wallaby ovulates, mates, conceives and forms a new embryo one to two days before the birth of their full-term fetus. Consequently, females are continuously pregnant throughout their reproductive life.The swamp wallaby is notable for having a distinct sex-chromosome system from most other Theria (the subclass that includes marsupials and placental mammals). Females are characterized by the XX pair typical of therians, but males have one X chromosome and two non-sequence homology Y chromosomes. This system is thought to arise from a series of chromosomal fusions over the last 6 million years.
Second Industrial Revolution Modern business management Second_Industrial_Revolution > Industry and technology > Modern business management This led to what was called "railroad accounting", which was later adopted by steel and other industries, and eventually became modern accounting. Later in the Second Industrial Revolution, Frederick Winslow Taylor and others in America developed the concept of scientific management or Taylorism. Scientific management initially concentrated on reducing the steps taken in performing work (such as bricklaying or shoveling) by using analysis such as time-and-motion studies, but the concepts evolved into fields such as industrial engineering, manufacturing engineering, and business management that helped to completely restructure the operations of factories, and later entire segments of the economy. Taylor's core principles included: replacing rule-of-thumb work methods with methods based on a scientific study of the tasks scientifically selecting, training, and developing each employee rather than passively leaving them to train themselves providing "detailed instruction and supervision of each worker in the performance of that worker's discrete task" dividing work nearly equally between managers and workers, such that the managers apply scientific-management principles to planning the work and the workers actually perform the tasks
Free loop Summary Free_loop_space In the mathematical field of topology, a free loop is a variant of the mathematical notion of a loop. Whereas a loop has a distinguished point on it, called a basepoint, a free loop lacks such a distinguished point. Formally, let X {\displaystyle X} be a topological space. Then a free loop in X {\displaystyle X} is an equivalence class of continuous functions from the circle S 1 {\displaystyle S^{1}} to X {\displaystyle X} .
Secondary metabolite Plant secondary metabolites in medicine Secondary_compounds > Plant secondary metabolites > Plant secondary metabolites in medicine Certain studies shown that flavonoids have direct antibiotic activity. A number of in vitro and limited in vivo studies shown that flavonoids such as quercetin have synergistic activity with antibiotics and are able to suppress bacterial loads.Digoxin is a cardiac glycoside first derived by William Withering in 1785 from the foxglove (Digitalis) plant. It is typically used to treat heart conditions such as atrial fibrillation, atrial flutter or heart failure. Digoxin can, however, have side effects such as nausea, bradycardia, diarrhea or even life-threatening arrhythmia.
Cl2Sn Uses Cl2Sn > Uses It also finds a use as a catalyst between acetone and hydrogen peroxide to form the tetrameric form of acetone peroxide. Tin(II) chloride also finds wide use as a reducing agent. This is seen in its use for silvering mirrors, where silver metal is deposited on the glass: Sn2+ (aq) + 2 Ag+ → Sn4+ (aq) + 2 Ag (s)A related reduction was traditionally used as an analytical test for Hg2+ (aq).
Anomaly cancellation Witten anomaly and Wang–Wen–Witten anomaly Anomaly_cancellation > Global anomalies > Large gauge transformations > Witten anomaly and Wang–Wen–Witten anomaly When a theory contains an odd number of flavors of chiral fermions, the actions of gauge symmetries in the identity component and the disconnected component of the gauge group on a physical state differ by a sign. Thus when one sums over all physical configurations in the path integral, one finds that contributions come in pairs with opposite signs.
Hot band Combination bands Hot_band > Combination bands As mentioned above, combination bands involve changes in vibrational quantum numbers of more than one normal mode. These transitions are forbidden by harmonic oscillator selection rules, but are observed in vibrational spectra of real systems due to anharmonic couplings of normal modes. Combination bands typically have weak spectral intensities, but can become quite intense in cases where the anharmonicity of the vibrational potential is large. Broadly speaking, there are two types of combination bands.
MicrobesOnline Gene carts MicrobesOnline > Functions and Site Architecture > Genetic information > Gene carts An important feature to store a user's work is the Gene Cart. Many web pages of MicrobesOnline displaying genetic information contain a link to add genes of interest to the session gene cart, which is available for all users. This is a temporary gene cart, and as such it loses information as a user closes the web browser. Genes in the session gene cart can be saved to the permanent gene cart which is only available to registered users after logging in.
Chromatic note Chromatic line Chromatic_note > Chromatic line In music theory, passus duriusculus is a Latin term which refers to chromatic line, often a bassline, whether descending or ascending. A line cliché is any chromatic line that moves against a stationary chord. There are many different types of line clichés—most often in the root, fifth or seventh—but there are two named line clichés. The major line cliché moves from the fifth of the chord to the sixth, then back to the fifth.
Hydroxide Transition and post-transition metals Hydroxyl_ion > Inorganic hydroxides > Transition and post-transition metals For example, silver hydroxide Ag(OH) decomposes spontaneously to the oxide (Ag2O). Copper(I) and gold(I) hydroxides are also unstable, although stable adducts of CuOH and AuOH are known. The polymeric compounds M(OH)2 and M(OH)3 are in general prepared by increasing the pH of an aqueous solutions of the corresponding metal cations until the hydroxide precipitates out of solution.
CDR coding Summary CDR_coding In computer science CDR coding is a compressed data representation for Lisp linked lists. It was developed and patented by the MIT Artificial Intelligence Laboratory, and implemented in computer hardware in a number of Lisp machines derived from the MIT CADR. CDR coding is in fact a fairly general idea; whenever a data object A ends in a reference to another data structure B, we can instead place the structure B itself there, overlapping and running off the end of A. By doing this we free the space required by the reference, which can add up if done many times, and also improve locality of reference, enhancing performance on modern machines. The transformation is especially effective for the cons-based lists it was created for; we free about half of the space for each node we perform this transformation on.
Cell division cycle Summary M_phase The cell cycle, or cell-division cycle, is the series of events that take place in a cell that causes it to divide into two daughter cells. These events include the duplication of its DNA (DNA replication) and some of its organelles, and subsequently the partitioning of its cytoplasm, chromosomes and other components into two daughter cells in a process called cell division. In cells with nuclei (eukaryotes, i.e., animal, plant, fungal, and protist cells), the cell cycle is divided into two main stages: interphase and the mitotic (M) phase (including mitosis and cytokinesis). During interphase, the cell grows, accumulating nutrients needed for mitosis, and replicates its DNA and some of its organelles.
Instrumentation and control engineering Summary Instrumentation_and_control_engineering Meanwhile, control engineering, also called control systems engineering, is the engineering discipline that applies control theory to design systems with desired behaviors. Control engineers are responsible for the research, design, and development of control devices and systems, typically in manufacturing facilities and process plants. Control methods employ sensors to measure the output variable of the device and provide feedback to the controller so that it can make corrections toward desired performance.
Soft Matter Distinctive physics Soft_matter_physics > Distinctive physics Self-assembly can be classified as static, where the resulting structure is due to a free energy minimum, or dynamic, which occurs when the system is caught in a metastable state. Dynamic self-assembly can be utilized in the functional design of soft materials with these metastable states through kinetic trapping.Soft materials often exhibit both elasticity and viscous responses to external stimuli, such as shear induced flow or phase transitions, however, excessive external stimuli often result in nonlinear responses. Soft matter becomes highly deformed before crack propagation, which differs significantly from the general fracture mechanics formulation. Rheology, the study of deformation under stress, is often used to investigate the bulk properties of soft matter.
Graph-based access control Organizational graph Graph-based_access_control > Definition > Organizational graph Additionally there are specific relationship types like "deputyship" or "informed_by". These types can be extended by the modeler. All relationships can be context sensitive through the usage of predicates.
Structural Formula Skeletal formulas Chemical_structure_diagram > Skeletal formulas An additional feature of skeletal formulas is that by adding certain structures the stereochemistry, that is the three-dimensional structure, of the compound can be determined. Often times, the skeletal formula can indicate stereochemistry through the use of wedges instead of lines. Solid wedges represent bonds pointing above the plane of the paper, whereas dashed wedges represent bonds pointing below the plane.
Feed-forward control Physiological feed-forward system Feedforward_Control > Applications > Physiological feed-forward system In physiology, feed-forward control is exemplified by the normal anticipatory regulation of heartbeat in advance of actual physical exertion by the central autonomic network. Feed-forward control can be likened to learned anticipatory responses to known cues (predictive coding). Feedback regulation of the heartbeat provides further adaptiveness to the running eventualities of physical exertion. Feedforward systems are also found in biological control of other variables by many regions of animals brains.Even in the case of biological feedforward systems, such as in the human brain, knowledge or a mental model of the plant (body) can be considered to be mathematical as the model is characterized by limits, rhythms, mechanics and patterns.A pure feed-forward system is different from a homeostatic control system, which has the function of keeping the body's internal environment 'steady' or in a 'prolonged steady state of readiness.' A homeostatic control system relies mainly on feedback (especially negative), in addition to the feedforward elements of the system.
History of thermodynamics Kinetic theory Theory_of_heat > Kinetic theory Further progress in kinetic theory started only in the middle of the 19th century, with the works of Rudolf Clausius, James Clerk Maxwell, and Ludwig Boltzmann. In his 1857 work On the nature of the motion called heat, Clausius for the first time clearly states that heat is the average kinetic energy of molecules. This interested Maxwell, who in 1859 derived the momentum distribution later named after him.
Wireline Logging Resistivity log Wireline_Logging > Wireline logging > Electrical logs > Resistivity log Resistivity logging measures the subsurface electrical resistivity, which is the ability to impede the flow of electric current. This helps to differentiate between formations filled with salty waters (good conductors of electricity) and those filled with hydrocarbons (poor conductors of electricity). Resistivity and porosity measurements are used to calculate water saturation. Resistivity is expressed in ohms.meter (Ω⋅m), and is frequently charted on a logarithm scale versus depth because of the large range of resistivity. The distance from the borehole penetrated by the current varies with the tool, from a few centimeters to one meter.
Delta cell Summary Delta_cells Viewed under an electron microscope, delta-cells can be identified as cells with smaller and slightly more compact granules than beta cells.The δ-cells in the stomach contain CCKBR (which respond to gastrin) and M3 receptors (which respond to Ach). Respectively, these receptors will increase somatostatin output and decrease somatostatin output from the δ-cells. VIP, vasoactive intestinal peptide, acts positively on δ-cells resulting in more somatostatin being released. In the stomach, somatostatin acts directly on the acid-producing parietal cells via a G-protein coupled receptor (which inhibits adenylate cyclase, thus effectively antagonising the stimulatory effect of histamine) to reduce acid secretion. Somatostatin can also indirectly decrease stomach acid production by preventing the release of other hormones, including gastrin, secretin and histamine which effectively slows down the digestive process.
Electro-optical MASINT Spectroscopic MASINT Electro-optical_MASINT > Spectroscopic MASINT For each point along a time-intensity radiometric plot, a spectral plot can be generated based on the number of spectral bands in the collector, such as the radiant intensity plot of a missile exhaust plume as the missile is in flight. The intensity or brightness of the object is a function of several conditions including its temperature, surface properties or material, and how fast it is moving. Remember that additional, non-electro-optical sensors, such as ionizing radiation detectors, can correlate with these bands.
Maple computer algebra system Examples of Maple code Maple_computer_algebra_system > Examples of Maple code The following code, which computes the factorial of a nonnegative integer, is an example of an imperative programming construct within Maple: Simple functions can also be defined using the "maps to" arrow notation:
Serotonin receptor agonist Summary Serotonin_receptor_agonist A serotonin receptor agonist is an agonist of one or more serotonin receptors. They activate serotonin receptors in a manner similar to that of serotonin (5-hydroxytryptamine; 5-HT), a neurotransmitter and hormone and the endogenous ligand of the serotonin receptors.
Real-time database Preserving data consistency Real-time_database > Preserving data consistency A database must let only one transaction operate at a time to preserve data consistency. For example, if two students demand to take the remaining spot for a section of a class and they hit submit at the same time, only one student should be able to register for it.Real-time databases can process these requests utilizing scheduling algorithms for concurrency control, prioritizing both students’ requests in some way. Throughout this article, we assume that the system has a single processor, a disk based database, and a main memory pool.In real-time databases, deadlines are formed and different kinds of systems respond to data that does not meet its deadline in different ways.
Inequalities in information theory Lower bounds for the Kullback–Leibler divergence Inequalities_in_information_theory > Lower bounds for the Kullback–Leibler divergence A great many important inequalities in information theory are actually lower bounds for the Kullback–Leibler divergence. Even the Shannon-type inequalities can be considered part of this category, since the interaction information can be expressed as the Kullback–Leibler divergence of the joint distribution with respect to the product of the marginals, and thus these inequalities can be seen as a special case of Gibbs' inequality. On the other hand, it seems to be much more difficult to derive useful upper bounds for the Kullback–Leibler divergence. This is because the Kullback–Leibler divergence DKL(P\|\|Q) depends very sensitively on events that are very rare in the reference distribution Q. DKL(P\|\|Q) increases without bound as an event of finite non-zero probability in the distribution P becomes exceedingly rare in the reference distribution Q, and in fact DKL(P\|\|Q) is not even defined if an event of non-zero probability in P has zero probability in Q. (Hence the requirement that P be absolutely continuous with respect to Q.)
Double-ended priority queue External sorting Double-ended_priority_queue > Applications > External sorting One example application of the double-ended priority queue is external sorting. In an external sort, there are more elements than can be held in the computer's memory. The elements to be sorted are initially on a disk and the sorted sequence is to be left on the disk. The external quick sort is implemented using the DEPQ as follows: Read in as many elements as will fit into an internal DEPQ.
Solar filter Narrowband Astronomical_filter > Nebular filters > Narrowband Narrow-band filters are astronomical filters which transmit only a narrow band of spectral lines from the spectrum (usually 22 nm bandwidth, or less). They are mainly used for nebulae observation. Emission nebulae mainly radiate the doubly ionized oxygen in the visible spectrum, which emits near 500 nm wavelength. These nebulae also radiate weakly at 486 nm, the Hydrogen-beta line. There are two main types of Narrowband filters: Ultra-high contrast (UHC), and specific emission line(s) filters.
Izod test The need for Impact tests Izod_test > The need for Impact tests Impact, by definition, is a large force applied for a very short time, resulting in a sudden transfer of momentum and energy, and its effect is different when the same amount of energy is transferred more gradually. Everyday engineering structures are subjected to it and may develop cracks that, over time, propagate to a point where catastrophic failure would result. Impact tests are used in comparing the shear fracture toughness of various materials under the same test conditions, or of one material versus temperature to determine its ductile-to-brittle transition temperature where a steep descent in impact strength with decreasing temperature is observed.
Pipe stress analysis Summary Piping_Design If necessary, pipes can be cleaned by the tube cleaning process. Piping sometimes refers to piping design, the detailed specification of the physical piping layout within a process plant or commercial building. In earlier days, this was sometimes called drafting, technical drawing, engineering drawing, and design, but is today commonly performed by designers that have learned to use automated computer-aided drawing or computer-aided design (CAD) software.
Elastic and inelastic collisions apparatus Summary Elastic_and_inelastic_collisions_apparatus This apparatus was illustrated by Jean-Antoine Nollet in Leçons de physique expérimentale (Paris, 1743–1748). In his description, Nollet claims to have merely altered and developed a model previously used by Edme Mariotte. The most sophisticated devices for studying elastic and inelastic collisions were built by Willem Jacob 's Gravesande and Petrus van Musschenbroek. The instrument is held in the Lorraine collections of the Museo Galileo in Florence.
Morse–Kelley set theory The axioms in Kelley's General Topology Morse–Kelley_set_theory > The axioms in Kelley's General Topology Definition: c is a choice function if c is a function and c ( x ) ∈ x {\displaystyle c(x)\in x} for each member x of domain c. IX. Choice: There exists a choice function c whose domain is V − { ∅ } . {\displaystyle V-\{\varnothing \}.}
Abdominal compartment syndrome Pathophysiology Abdominal_compartment_syndrome > Pathophysiology The underlying cause of the disease process is capillary permeability caused by the systemic inflammatory response syndrome (SIRS) that occurs in every critically ill patient. SIRS leads to leakage of fluid out of the capillary beds into the interstitial space in the entire body with a profound amount of this fluid leaking into the gut wall, mesentery and retroperitoneal tissue. Abdominal compartment syndrome follows a destructive pathway similar to compartment syndrome of the extremities.
Endemic pemphigus Summary Endemic_pemphigus Pemphigus foliaceus is an autoimmune (blistering disease) of the skin. Pemphigus foliaceus causes a characteristic inflammatory attack at the subcorneal layer of epidermis, which results in skin lesions that are scaly or crusted erosions with an erythematous (red) base. Mucosal involvement is absent even with widespread disease.If there is an autoimmune IgG buildup in the epidermis, then nearly all of the antibodies are aimed against desmoglein 1.
Septal nuclei The lateral septum and movement and reward Septal_nuclei > Functions of the lateral septum > The lateral septum and movement and reward The lateral septum is involved in a variety of functions, including emotional, motivational, and spatial behavior. It has been suggested that the LS may regulate interactions between the hippocampus and other regions that mediate goal directed behavior, such as the ventral tegmental area. Firing of LS neurons is modulated by both speed and acceleration and spatial location, and that firing is also related to reward and context. It has thus been suggested that the lateral septum may incorporate movement into the evaluation of environmental context with respect to motivation and reward.
Differential calculus Summary Differential_calculus The reaction rate of a chemical reaction is a derivative. In operations research, derivatives determine the most efficient ways to transport materials and design factories.
Holographic principle Limit on information density Holographic_principle > Limit on information density Information content is defined as the logarithm of the reciprocal of the probability that a system is in a specific microstate, and the information entropy of a system is the expected value of the system's information content. This definition of entropy is equivalent to the standard Gibbs entropy used in classical physics. Applying this definition to a physical system leads to the conclusion that, for a given energy in a given volume, there is an upper limit to the density of information (the Bekenstein bound) about the whereabouts of all the particles which compose matter in that volume. In particular, a given volume has an upper limit of information it can contain, at which it will collapse into a black hole.
Environmental stress cracking Exposure of polymers to solvents Environmental_stress_cracking > Exposure of polymers to solvents Instead, it breaks the secondary linkages between polymers. These are broken when the mechanical stresses cause minute cracks in the polymer and they propagate rapidly under the harsh environmental conditions. It has also been seen that catastrophic failure under stress can occur due to the attack of a reagent that would not attack the polymer in an unstressed state. Environmental stress cracking is accelerated due to higher temperatures, cyclic loading, increased stress concentrations, and fatigue.Metallurgists typically use the term Stress corrosion cracking or Environmental stress fracture to describe this type of failure in metals.
Complex Systems Complexity economics Complex_systems_theory > Applications > Complexity economics Over the last decades, within the emerging field of complexity economics, new predictive tools have been developed to explain economic growth. Such is the case with the models built by the Santa Fe Institute in 1989 and the more recent economic complexity index (ECI), introduced by the MIT physicist Cesar A. Hidalgo and the Harvard economist Ricardo Hausmann. Recurrence quantification analysis has been employed to detect the characteristic of business cycles and economic development. To this end, Orlando et al. developed the so-called recurrence quantification correlation index (RQCI) to test correlations of RQA on a sample signal and then investigated the application to business time series. The said index has been proven to detect hidden changes in time series. Further, Orlando et al., over an extensive dataset, shown that recurrence quantification analysis may help in anticipating transitions from laminar (i.e. regular) to turbulent (i.e. chaotic) phases such as USA GDP in 1949, 1953, etc. Last but not least, it has been demonstrated that recurrence quantification analysis can detect differences between macroeconomic variables and highlight hidden features of economic dynamics.
Genetic informatics BioCompute and BioCompute Objects Bioinformatics > Software and tools > BioCompute and BioCompute Objects The US FDA funded this work so that information on pipelines would be more transparent and accessible to their regulatory staff.In 2016, the group reconvened at the NIH in Bethesda and discussed the potential for a BioCompute Object, an instance of the BioCompute paradigm. This work was copied as both a "standard trial use" document and a preprint paper uploaded to bioRxiv. The BioCompute object allows for the JSON-ized record to be shared among employees, collaborators, and regulators.
Arithmetic circuit Definitions Arithmetic_circuit_complexity > Definitions For example, the circuit in the figure has size six and depth two. An arithmetic circuit computes a polynomial in the following natural way. An input gate computes the polynomial it is labeled by.
Fourier Analysis (Continuous) Fourier transform Fourier_synthesis > Variants of Fourier analysis > (Continuous) Fourier transform Most often, the unqualified term Fourier transform refers to the transform of functions of a continuous real argument, and it produces a continuous function of frequency, known as a frequency distribution. One function is transformed into another, and the operation is reversible. When the domain of the input (initial) function is time (t), and the domain of the output (final) function is ordinary frequency, the transform of function s(t) at frequency f is given by the complex number: S ( f ) = ∫ − ∞ ∞ s ( t ) ⋅ e − i 2 π f t d t . {\displaystyle S(f)=\int _{-\infty }^{\infty }s(t)\cdot e^{-i2\pi ft}\,dt.}
Non-communicable disease Chronic respiratory disease Non-communicable_disease > Key diseases > Chronic respiratory disease Chronic Respiratory Diseases (CRDs) are diseases of the lungs and airways. According to the World Health Organization (WHO) hundreds of millions of people have CRDs. Common CRDs are: Asthma, Chronic obstructive pulmonary disease, Occupational lung disease, and Pulmonary hypertension. While CRDs are not curable, various treatments are available to help improve quality of life for individuals who have them.
Lottery Math Choosing 6 from 49 Lottery_Math > Choosing 6 from 49 When the draw comes to the second number, there are now only 48 balls left in the bag, because the balls are drawn without replacement. So there is now a 1 in 48 chance of predicting this number. Thus for each of the 49 ways of choosing the first number there are 48 different ways of choosing the second.
Metalloid Summary Metalloid They can form alloys with metals. Most of their other physical properties and chemical properties are intermediate in nature. Metalloids are usually too brittle to have any structural uses.
Subscript and superscript Subscripts that are dropped below the baseline Subscript_and_superscript > Subscripts that are dropped below the baseline Perhaps the most familiar example of subscripts is in chemical formulas. For example, the chemical formula for glucose is C6H12O6 (meaning that it is a molecule with 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms). One of the most famous molecules, water, is known almost universally by its chemical formula: H2O (meaning that it contains 2 hydrogen atoms and 1 oxygen atom). A subscript is also used to distinguish between different versions of a subatomic particle.
Contract Bridge Setup and dealing Contract_Bridge > Gameplay > Setup and dealing In rubber bridge each player draws a card at the start of the game; the player who draws the highest card deals first. The second highest card becomes the dealer's partner and takes the chair on the opposite side of the table. They play against the other two.
Parkinson disease The neuroimmune connection Parkinson_disease > Pathophysiology > The neuroimmune connection The neuroimmune interaction is heavily implicated in PD pathology. PD and autoimmune disorders share genetic variations and molecular pathways. Some autoimmune diseases may even increase one's risk of developing PD, up to 33% in one study. Autoimmune diseases linked to protein expression profiles of monocytes and CD4+ T cells are linked to PD.
Alloy of aluminium and manganese Manganism Alloy_of_aluminium_and_manganese > Health and safety > Manganism In its early stages, an intoxicated person may experience depression, mood swings, compulsive behaviors, and psychosis. Early neurological symptoms give way to late-stage manganism, which resembles Parkinson's disease. Symptoms include weakness, monotone and slowed speech, an expressionless face, tremor, forward-leaning gait, inability to walk backwards without falling, rigidity, and general problems with dexterity, gait and balance.
Stellar nucleosynthesis Helium fusion Hydrogen_fusion > Key reactions > Helium fusion Main sequence stars accumulate helium in their cores as a result of hydrogen fusion, but the core does not become hot enough to initiate helium fusion. Helium fusion first begins when a star leaves the red giant branch after accumulating sufficient helium in its core to ignite it. In stars around the mass of the Sun, this begins at the tip of the red giant branch with a helium flash from a degenerate helium core, and the star moves to the horizontal branch where it burns helium in its core. More massive stars ignite helium in their core without a flash and execute a blue loop before reaching the asymptotic giant branch.
Lightning Memory-Mapped Database API and uses Lightning_Memory-Mapped_Database > API and uses It is also available in some other NoSQL projects like MemcacheDB and Mapkeeper. LMDB was used to make the in-memory store Redis persist data on disk. The existing back-end in Redis showed pathological behaviour in rare cases, and a replacement was sought. The baroque API of LMDB was criticized though, forcing a lot of coding to get simple things done. However, its performance and reliability during testing was considerably better than the alternative back-end stores that were tried.An independent third-party software developer utilised the Python bindings to LMDB in a high-performance environment and published, on the technology news site Slashdot, how the system managed to successfully sustain 200,000 simultaneous read, write and delete operations per second (a total of 600,000 database operations per second).An up-to-date list of applications using LMDB is maintained on the main web site.
Info-gap decision theory Classical decision theory perspective Info-gap_decision_theory > Classical decision theory perspective Sniedovich raises two points to info-gap, from the point of view of classical decision theory, one substantive, one scholarly: the info-gap uncertainty model is flawed and oversold Under severe uncertainty, one should use global decision theory , not local decision theory. info-gap is maximin Ben-Haim (2006, p.xii) claims that info-gap is "radically different from all current theories of decision under uncertainty,". Ben-Haim states (Ben-Haim 1999, pp. 271–2) that "robust reliability is emphatically not a worst-case analysis".Sniedovich has challenged the validity of info-gap theory for making decisions under severe uncertainty.
Artificial Neural Networks History Parameter_(machine_learning) > History This was called "artificial curiosity." In 2014, this principle was used in a generative adversarial network (GAN) by Ian Goodfellow et al. Here the environmental reaction is 1 or 0 depending on whether the first network's output is in a given set. This can be used to create realistic deepfakes.
Resistors in series Thick and thin film Non-ideal_resistor > Fixed resistors > Thick and thin film Thick film resistors are manufactured using screen and stencil printing processes.Because the time during which the sputtering is performed can be controlled, the thickness of the thin film can be accurately controlled. The type of material also varies, consisting of one or more ceramic (cermet) conductors such as tantalum nitride (TaN), ruthenium oxide (RuO2), lead oxide (PbO), bismuth ruthenate (Bi2Ru2O7), nickel chromium (NiCr), or bismuth iridate (Bi2Ir2O7). The resistance of both thin and thick film resistors after manufacture is not highly accurate; they are usually trimmed to an accurate value by abrasive or laser trimming.
Red Valerian Description Red_Valerian > Description The blooms have a strong and somewhat rank scent. They are pollinated by both bees and butterflies and the plant is noted for attracting insects. It is used as a food plant by the larvae of some Lepidoptera species including angle shades. Seeds have tufts similar to dandelions that allow wind dispersal, and as such can self-seed freely and become invasive if not properly controlled.
Inductive charging Safety Induction_charger > Safety This much exposure to the skin of a human could prove harmful if not met within the right conditions. Exposure limits can be satisfied even when the transmitter coil is very close to the body.Testing has been done on how organs can be affected by these fields when put under low levels of frequency from these fields. When exposed to various levels of frequencies, dizziness, light flashes, or tingling through nerves can be experienced.
Earthquake Network Project development Earthquake_Network > Project development The Earthquake Network project is expected to solve 4 main problems related to earthquake detection and location using a smartphone network.
Fast User Switching In Linux Fast_User_Switching > In Linux The Linux kernel's VT subsystem dates back to 1993 and does not understand the concept of multiple "seats", meaning that of up to 63 VTs, only one VT can be active at any given time. Despite this kernel limitation, multi-seat is supported on Linux. The feature of "fast user switching" has less severe necessities than multi-seat does because the multiple users are not working simultaneously.The most straight forward solution to elegant multi-seat are kmscon/systemd-consoled in combination with systemd-logind. The available desktop environments such as GNOME or KDE Software Compilation adapt their graphical login and session manager (e.g. GDM, SDDM, LightDM, etc.) to the underneath solution and have to be configured to implement fast user switching that way.
Strain gauges Other types Strain_Gauge > Other types A semiconductor gauge usually has a larger gauge factor than a foil gauge. Semiconductor gauges tend to be more expensive, more sensitive to temperature changes, and are more fragile than foil gauges. Nanoparticle-based strain gauges emerge as a new promising technology.
Friction torque Examples Friction_torque > Examples When a cyclist applies the brake to the forward wheel, the bicycle tips forward due to the frictional torque between the wheel and the ground. When a golf ball hits the ground it begins to spin in part because of the friction torque applied to the golf ball from the friction between the golf ball and the ground.
Air–water partitioning coefficient Henry solubility defined via molality (Hsbp) Solubility_of_gases_in_liquids > Fundamental types and variants of Henry's law constants > Henry's law solubility constants Hs > Henry solubility defined via molality (Hsbp) The SI unit for H s b p {\displaystyle H_{\rm {s}}^{bp}} is mol/(kg·Pa). There is no simple way to calculate H s c p {\displaystyle H_{\rm {s}}^{cp}} from H s b p {\displaystyle H_{\rm {s}}^{bp}} , since the conversion between concentration c a {\displaystyle c_{\text{a}}} and molality b {\displaystyle b} involves all solutes of a solution. For a solution with a total of n {\displaystyle n} solutes with indices i = 1 , … , n {\displaystyle i=1,\ldots ,n} , the conversion is: c a = b ϱ 1 + ∑ i = 1 n b i M i , {\displaystyle c_{\text{a}}={\frac {b\varrho }{1+\sum _{i=1}^{n}b_{i}M_{i}}},} where ϱ {\displaystyle \varrho } is the density of the solution, and M i {\displaystyle M_{i}} are the molar masses.
Snatch block Friction Snatch_block > Mechanical advantage > Friction In order to raise a block and tackle with a mechanical advantage of 6 a distance of 1 metre, it is necessary to pull 6 metres of rope through the blocks. Frictional losses also mean there is a practical point at which the benefit of adding a further sheave is offset by the incremental increase in friction which would require additional force to be applied in order to lift the load. Too much friction may result in the tackle not allowing the load to be released easily, or by the reduction in force needed to move the load being judged insufficient because undue friction has to be overcome as well.
Hughes–Ingold symbol Summary Hughes–Ingold_symbol A Hughes–Ingold symbol describes various details of the reaction mechanism and overall result of a chemical reaction. For example, an SN2 reaction is a substitution reaction ("S") by a nucleophilic process ("N") that is bimolecular ("2" molecular entities involved) in its rate-determining step. By contrast, an E2 reaction is an elimination reaction, an SE2 reaction involves electrophilic substitution, and an SN1 reaction is unimolecular. The system is named for British chemists Edward D. Hughes and Christopher Kelk Ingold. == References ==
Five safes The 'data access spectrum' Five_safes > The 'data access spectrum' From 2003 the Five Safes was also represented in a simpler form as a 'Data Access Spectrum'.The non-data controls (project, people, setting, outputs) tend to work together, in that organisations often see these as a complementary set of restrictions on access. These can then be contrasted with choices about data anonymisation to present a linear representation of data access options. This presentation is consistent with the idea of 'data as a residual', as well as data protection laws of the time which often characterised data simply as anonymous or not anonymous. A similar idea had already been developed independently in 2001 by Chuck Humphrey of the Canadian RDC network, the 'continuum of access'. More recently, The Open Data Institute has developed a 'Data Spectrum toolkit' which includes industry-specific examples.
Ranitidine Former medical uses Ranitidine > Former medical uses In a 2009 meta-analysis comparing the net benefit of PPIs and ranitidine to reduce the risk of aspiration before anaesthesia, ranitidine was found to be more effective than PPIs in reducing the volume of gastric secretions. Ranitidine may have an anti-emetic effect when administered preoperatively. Prevention of stress-induced ulcers in critically ill patients Used together with diphenhydramine as secondary treatment for anaphylaxis; after first-line epinephrine.
Coulometric titration Potentiostatic coulometry Coulometric_titration > Potentiostatic coulometry Potentiostatic coulometry is a technique most commonly referred to as "bulk electrolysis". The working electrode is kept at a constant potential and the current that flows through the circuit is measured. This constant potential is applied long enough to fully reduce or oxidize all of the electroactive species in a given solution. As the electroactive molecules are consumed, the current also decreases, approaching zero when the conversion is complete.
Moving part Mechanical efficiency and wear Moving_part > Mechanical efficiency and wear The amount of moving parts in a machine is a factor in its mechanical efficiency. The greater the number of moving parts, the greater the amount of energy lost to heat by friction between those parts. For example, in a modern automobile engine, roughly 7% of the total power obtained from burning the engine's fuel is lost to friction between the engine's moving parts.Conversely, the fewer the number of moving parts, the greater the efficiency. Machines with no moving parts at all can be very efficient.
History of the periodic table Recognition of Mendeleev's table History_of_the_periodic_table > Priority dispute and recognition > Recognition of Mendeleev's table Mendeleev contacted all three discoverers; all three noted the close similarity of their discovered elements with Mendeleev's predictions, with the last of them, German chemist Clemens Winkler, admitting this suggestion was not first made by Mendeleev or himself after the correspondence with him, but by a different person, German chemist Hieronymous Theodor Richter. Some contemporary chemists were not convinced by these discoveries, noting the dissimilarities between the new elements and the predictions or claiming those similarities that did exist were coincidental. However, success of Mendeleev's predictions helped spread the word about his periodic table.
Gas-generator cycle (rocket) Summary Gas-generator_cycle The Gas Generator Cycle, also called open cycle, is one of the most commonly used power cycles in bipropellant liquid rocket engines. Part of the unburned propellant is burned in a gas generator (or preburner) and the resulting hot gas is used to power the propellant pumps before being exhausted overboard, and lost. Because of this loss, this type of engine is termed open cycle. The gas generator cycle exhaust products pass over the turbine first.
Separable partial differential equation Summary Separable_partial_differential_equation The most common form of separation of variables is simple separation of variables in which a solution is obtained by assuming a solution of the form given by a product of functions of each individual coordinate. There is a special form of separation of variables called R {\displaystyle R} -separation of variables which is accomplished by writing the solution as a particular fixed function of the coordinates multiplied by a product of functions of each individual coordinate. Laplace's equation on R n {\displaystyle {\mathbb {R} }^{n}} is an example of a partial differential equation which admits solutions through R {\displaystyle R} -separation of variables; in the three-dimensional case this uses 6-sphere coordinates. (This should not be confused with the case of a separable ODE, which refers to a somewhat different class of problems that can be broken into a pair of integrals; see separation of variables.)
Pin and hanger assembly Summary Pin_and_hanger_assembly The beams have holes directly above each other. The two holes are connected using hangers, a pair of connecting plates sandwiching the bridge girders. A pair of large steel pins through the plates and girder webbing provide the hinges, holding up the suspended span while allowing it to move longitudinally. Large washers are bolted to each end of the pin to retain the hangers. Exceptionally long spans may have two sets of girders cantilevered from opposite bridge piers with a third set of girders suspended by pin and hanger assemblies from both cantilevers.
Paley-Wiener theorem Holomorphic Fourier transforms Paley-Wiener_criterion > Holomorphic Fourier transforms This is a very useful result as it enables one to pass to the Fourier transform of a function in the Hardy space and perform calculations in the easily understood space L 2 ( R + ) {\displaystyle L^{2}(\mathbb {R} _{+})} of square-integrable functions supported on the positive axis. By imposing the alternative restriction that F {\displaystyle F} be compactly supported, one obtains another Paley–Wiener theorem.
Specific entropy Entropy in chemical thermodynamics Molar_entropy > Applications > Entropy in chemical thermodynamics Entropy change describes the direction and quantifies the magnitude of simple changes such as heat transfer between systems – always from hotter to cooler spontaneously. The thermodynamic entropy therefore has the dimension of energy divided by temperature, and the unit joule per kelvin (J/K) in the International System of Units (SI). Thermodynamic entropy is an extensive property, meaning that it scales with the size or extent of a system.
Axiom of constructibility Summary Axiom_of_constructibility The axiom of constructibility is a possible axiom for set theory in mathematics that asserts that every set is constructible. The axiom is usually written as V = L. The axiom, first investigated by Kurt Gödel, is inconsistent with the proposition that zero sharp exists and stronger large cardinal axioms (see list of large cardinal properties). Generalizations of this axiom are explored in inner model theory.
Water infrastructure Population growth Water_supply_network > Sustainable urban water supply > Population growth Attempts to expand water supply by governments are costly and often not sufficient. The building of new illegal settlements makes it hard to map, and make connections to, the water supply, and leads to inadequate water management. In 2002, there were 158 million people with inadequate water supply. An increasing number of people live in slums, in inadequate sanitary conditions, and are therefore at risk of disease.
Building collapse Introduction Structural_integrity_and_failure > Introduction Structural integrity is the ability of a structure to withstand its intended loading without failing due to fracture, deformation, or fatigue. It is a concept often used in engineering to produce items that will serve their designed purposes and remain functional for a desired service life. To construct an item with structural integrity, an engineer must first consider a material's mechanical properties, such as toughness, strength, weight, hardness, and elasticity, and then determine the size and shape necessary for the material to withstand the desired load for a long life. Since members can neither break nor bend excessively, they must be both stiff and tough.
Differential element Differentials as linear maps on a vector space Variable_of_integration > Approaches > Differentials as linear maps > Differentials as linear maps on a vector space The same procedure works on a vector space with a enough additional structure to reasonably talk about continuity. The most concrete case is a Hilbert space, also known as a complete inner product space, where the inner product and its associated norm define a suitable concept of distance. The same procedure works for a Banach space, also known as a complete Normed vector space.
Repeating circle Construction and operation Repeating_circle > Construction and operation The repeating circle is made of two telescopes mounted on a shared axis with scales to measure the angle between the two. The instrument combines multiple measurements to increase accuracy with the following procedure: At this stage, the angle on the instrument is double the angle of interest between the points. Repeating the procedure causes the instrument to show 4× the angle of interest, with further iterations increasing it to 6×, 8×, and so on. In this way, many measurements can be added together, allowing some of the random measurement errors to cancel out.
Acta Biotheoretica Summary Acta_Biotheoretica Acta Biotheoretica: Mathematical and philosophical foundations of biological and biomedical science is a quarterly peer-reviewed scientific journal published by Springer Science+Business Media. It is the official journal of the Jan van der Hoeven Society for Theoretical Biology. The editor-in-chief is F.J.A. Jacobs (Leiden University).
Quasi-harmonic approximation Overview Quasi-harmonic_approximation > Overview The quasi-harmonic approximation expands upon the harmonic phonon model of lattice dynamics. The harmonic phonon model states that all interatomic forces are purely harmonic, but such a model is inadequate to explain thermal expansion, as the equilibrium distance between atoms in such a model is independent of temperature. Thus in the quasi-harmonic model, from a phonon point of view, phonon frequencies become volume-dependent in the quasi-harmonic approximation, such that for each volume, the harmonic approximation holds.
Mycobacterial disease Nontuberculosis Mycobacteria Mycobacterial_disease > Pathogenicity > Nontuberculosis Mycobacteria Nontuberculosis Mycobacteria (NTM), which exclude M. tuberculosis, M. leprae, and M. lepromatosis, can infect mammalian hosts. These bacteria are referred to as "atypical mycobacteria." Although person-to-person transmission is rare, transmission of M. abscessus has been observed between patients with cystic fibrosis. The four primary diseases observed in humans are chronic pulmonary disease, disseminated disease in immunocompromised patients, skin and soft tissue infections, and superficial lymphadenitis.
Vector generalized linear model Vector generalized additive models Vector_generalized_linear_model > Extensions > Vector generalized additive models These are M additive predictors. Each smooth function f ( j ) k ∗ {\displaystyle f_{(j)k}^{*}} is estimated from the data. Thus VGLMs are model-driven while VGAMs are data-driven.
Coherent effects in semiconductor optics Summary Coherent_effects_in_semiconductor_optics The optical polarization is a genuine non-equilibrium quantity that decays to zero when the excited system relaxes to its equilibrium state after the electromagnetic pulse is switched off. Due to this decay which is called dephasing, coherent effects are observable only for a certain temporal duration after pulsed photoexcitation. Various materials such as atoms, molecules, metals, insulators, semiconductors are studied using coherent optical spectroscopy and such experiments and their theoretical analysis has revealed a wealth of insights on the involved matter states and their dynamical evolution.
Bile acids Summary Bile_salt An increased secretion of bile acids produces an increase in bile flow. Bile acids facilitate digestion of dietary fats and oils.
Wireless energy transmission Electrodynamic Wireless Power Transfer Microwave_power_transmission > Near-field (nonradiative) techniques > Electrodynamic Wireless Power Transfer An electrodynamic wireless power transfer (EWPT) system utilizes a receiver with a mechanically resonating or rotating permanent magnet. When subjected to a time-varying magnetic field, the mechanical motion of the resonating magnet is converted into electricity by one or more electromechanical transduction schemes (e.g. electromagnetic/induction, piezoelectric, or capacitive). In contrast to inductive coupling systems which usually use high frequency magnetic fields, EWPT uses low-frequency magnetic fields (<1 kHz), which safely pass through conductive media and have higher human field exposure limits (~2 mTrms at 1 kHz), showing promise for potential use in wirelessly recharging biomedical implants. For EWPT devices having identical resonant frequencies, the magnitude of power transfer is entirely dependent on critical coupling coefficient, denoted by k {\displaystyle k} , between the transmitter and receiver devices.
Inertial fusion Thermonuclear devices 4_pi_laser > Description > Thermonuclear devices The electrically neutral neutrons travel longer distances in the fuel mass and do not contribute to this self-heating process. In a bomb, they are instead used to either breed tritium through reactions in a lithium-deuteride fuel, or are used to split additional fissionable fuel surrounding the secondary stage, often part of the bomb casing.The requirement that the reaction has to be sparked by a fission bomb makes this method impractical for power generation. Not only would the fission triggers be expensive to produce, but the minimum size of such a bomb is large, defined roughly by the critical mass of the plutonium fuel used.
Sketch based modeling Operation Sketch_based_modeling > Operation The process of adding sections to a model is generally referred to as overdrawing. The user is never required to interact directly with the vertices or Nurbs control points. In the second type of sketch-based modeling, the user draws one or more images on paper, then scans in the images. The system then automatically converts the sketches to a 3D model.
Physics (Aristotle) Significance to philosophy and science in the modern world Physics_(Aristotle) > Significance to philosophy and science in the modern world The works of Aristotle are typically influential to the development of Western science and philosophy. The citations below are not given as any sort of final modern judgement on the interpretation and significance of Aristotle, but are only the notable views of some moderns.
Frank-Kamenetskii theory Steady-state regime Frank-Kamenetskii_theory > Semenov theory > Steady-state regime When 0 < δ < e − 1 {\displaystyle 0<\delta
Lunar gravity Gravitational field Lunar_gravity > Gravitational field The gravitational field of the Moon has been measured by tracking the radio signals emitted by orbiting spacecraft. The principle used depends on the Doppler effect, whereby the line-of-sight spacecraft acceleration can be measured by small shifts in frequency of the radio signal, and the measurement of the distance from the spacecraft to a station on Earth. Since the gravitational field of the Moon affects the orbit of a spacecraft, one can use this tracking data to detect gravity anomalies. Most low lunar orbits are unstable.
Marine sanitation device Advanced water treatment Marine_sanitation_device > Treatment > Advanced water treatment The waste influent is then passed through Oxidation Reactors which serve to oxidize pollutants and aid the production of carbon dioxide gas and water. The seventh and final stage consists of a powerful Ultraviolet Reactor in which the ozonated water is broken down into oxygen compounds that provide further treatment of the water. The leftover solids are then oxidized which provide safe bio-disposal or land based discharge if needed.
Electric distribution network 220–240 volt systems Distribution_network > Secondary distribution > Regional variations > 220–240 volt systems Transformers are typically sized on an average load of 1 to 2 kW per household, and the service fuses and cable is sized to allow any one property to draw a peak load of perhaps ten times this. For industrial customers, 3-phase 690 / 400 volt is also available, or may be generated locally. Large industrial customers have their own transformer(s) with an input from 11 kV to 220 kV.
Optimal design of experiments Historical Optimal_design_of_experiments > Further reading > Historical 1958. paragraphs 139–157, and in Peirce, C. S. (July–August 1967). "Note on the Theory of the Economy of Research".
Solomonoff's theory of inductive inference Mathematical Solomonoff's_theory_of_inductive_inference > Origin > Mathematical The proof of the "razor" is based on the known mathematical properties of a probability distribution over a countable set. These properties are relevant because the infinite set of all programs is a denumerable set. The sum S of the probabilities of all programs must be exactly equal to one (as per the definition of probability) thus the probabilities must roughly decrease as we enumerate the infinite set of all programs, otherwise S will be strictly greater than one.
Bohm diffusion Approximate derivation Bohm_diffusion > Approximate derivation On the other hand, if the collision frequency is larger than the gyrofrequency, then the particles can be considered to move freely with the thermal velocity vth between collisions, and the diffusion coefficient takes the form D = v t h 2 / ν {\displaystyle D=v_{\rm {th}}^{2}/\nu } . In this regime, the diffusion is maximum when the collision frequency is equal to the gyrofrequency, in which case D = ρ 2 ω c = v t h 2 / ω c {\displaystyle D=\rho ^{2}\omega _{\rm {c}}=v_{\rm {th}}^{2}/\omega _{\rm {c}}} . Substituting ρ = v t h / ω c , v t h = ( k B T / m ) 1 / 2 {\displaystyle \rho =v_{\rm {th}}/\omega _{\rm {c}},\;v_{\rm {th}}=(k_{\rm {B}}T/m)^{1/2}} , and ω c = e B / m {\displaystyle \omega _{\rm {c}}=eB/m} (the cyclotron frequency), we arrive at D = k B T / e B , {\displaystyle D=k_{\rm {B}}T/eB,} which is the Bohm scaling.
Electromagnetic units General literature Electrostatic_units > General literature Griffiths, David J. (1999). "Appendix C: Units". Introduction to Electrodynamics (3rd ed.).
Grid graph Square grid graph Grid_graph > Square grid graph A common type of a lattice graph (known under different names, such as square grid graph) is the graph whose vertices correspond to the points in the plane with integer coordinates, x-coordinates being in the range 1, ..., n, y-coordinates being in the range 1, ..., m, and two vertices are connected by an edge whenever the corresponding points are at distance 1. In other words, it is a unit distance graph for the described point set.
History of chemistry Josiah Willard Gibbs History_of_chemistry > 19th century > Josiah Willard Gibbs Since virtually all chemical processes and many physical ones involve such changes, his work has significantly impacted both the theoretical and experiential aspects of these sciences. In 1877, Ludwig Boltzmann established statistical derivations of many important physical and chemical concepts, including entropy, and distributions of molecular velocities in the gas phase. Together with Boltzmann and James Clerk Maxwell, Gibbs created a new branch of theoretical physics called statistical mechanics (a term that he coined), explaining the laws of thermodynamics as consequences of the statistical properties of large ensembles of particles.
Mathematical ecology Structured population growth Mathematical_ecology > Population ecology > Structured population growth Another assumption of the exponential growth model is that all individuals within a population are identical and have the same probabilities of surviving and of reproducing. This is not a valid assumption for species with complex life histories. The exponential growth model can be modified to account for this, by tracking the number of individuals in different age classes (e.g. one-, two-, and three-year-olds) or different stage classes (juveniles, sub-adults, and adults) separately, and allowing individuals in each group to have their own survival and reproduction rates.
Optical pathway Mechanism of generating visual signals Optical_pathway > Structure > Eye > Retina > Mechanism of generating visual signals The retina adapts to change in light through the use of the rods. In the dark, the chromophore retinal has a bent shape called cis-retinal (referring to a cis conformation in one of the double bonds). When light interacts with the retinal, it changes conformation to a straight form called trans-retinal and breaks away from the opsin. This is called bleaching because the purified rhodopsin changes from violet to colorless in the light.
Category of representations Summary Category_of_representations In representation theory, the category of representations of some algebraic structure A has the representations of A as objects and equivariant maps as morphisms between them. One of the basic thrusts of representation theory is to understand the conditions under which this category is semisimple; i.e., whether an object decomposes into simple objects (see Maschke's theorem for the case of finite groups). The Tannakian formalism gives conditions under which a group G may be recovered from the category of representations of it together with the forgetful functor to the category of vector spaces.The Grothendieck ring of the category of finite-dimensional representations of a group G is called the representation ring of G.

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