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Symmetrization n variables Symmetric_map > n variables More generally, given a function in n {\displaystyle n} variables, one can symmetrize by taking the sum over all n ! {\displaystyle n!} permutations of the variables, or antisymmetrize by taking the sum over all n ! / 2 {\displaystyle n!/2} even permutations and subtracting the sum over all n !
Domain coloring Motivation Domain_coloring > Motivation A graph of a real function can be drawn in two dimensions because there are two represented variables, x {\displaystyle x} and y {\displaystyle y} . However, complex numbers are represented by two variables and therefore two dimensions; this means that representing a complex function (more precisely, a complex-valued function of one complex variable f: C → C {\displaystyle f:\mathbb {C} \to \mathbb {C} } ) requires the visualization of four dimensions. One way to achieve that is with a Riemann surface, but another method is by domain coloring.
Isoniazid Tuberculosis Isoniazid > Medical uses > Tuberculosis Isoniazid is often used to treat latent and active tuberculosis infections. In persons with isoniazid-sensitive Mycobacterium tuberculosis infection, drug regimens based on isoniazid are usually effective when persons adhere to the prescribed treatment. However, in persons with isoniazid-resistant Mycobacterium tuberculosis infection, drug regimens based on isoniazid have a high rate of failure.Isoniazid has been approved as prophylactic therapy for the following populations: People with HIV infection and a PPD (purified protein derivative) reaction of at least 5 mm induration Contacts of people with tuberculosis and who have a PPD reaction at least 5 mm induration People whose PPD reactions convert from negative to positive in a two-year period – at least 10 mm induration for those up to 35 years of age, and at least 15 mm induration for those at least 35 years old People with pulmonary damage on their chest X-ray that is likely to be due to healed tuberculosis and also have a PPD reaction at least 5 mm induration Injection drug users whose HIV status is negative who have a PPD reaction at least 10 mm induration People with a PPD of greater than or equal to 10 mm induration who are foreign-born from high prevalence geographical regions, low-income populations, and patients residing in long-term facilitiesIsoniazid can be used alone or in combination with Rifampin for treatment of latent tuberculosis, or as part of a four-drug regimen for treatment of active tuberculosis. The drug regimen typically requires daily or weekly oral administration for a period of three to nine months, often under Directly Observed Therapy (DOT) supervision.
ISO speed Summary Slow_film Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system introduced in the mid-1970s. A closely related ISO system is used to describe the relationship between exposure and output image lightness in digital cameras. Prior to ISO gaining traction the best known systems were ASA in the U.S.
Period (periodic table) Period 1 Second-row_transition_metal > Periods > Period 1 Stars in the main sequence are mainly composed of hydrogen in its plasma state. Elemental hydrogen is relatively rare on Earth, and is industrially produced from hydrocarbons such as methane. Hydrogen can form compounds with most elements and is present in water and most organic compounds.
Continuous-time dynamical system Nonlinear dynamical systems and chaos Non-linear_dynamics > Ergodic systems > Nonlinear dynamical systems and chaos Simple nonlinear dynamical systems and even piecewise linear systems can exhibit a completely unpredictable behavior, which might seem to be random, despite the fact that they are fundamentally deterministic. This seemingly unpredictable behavior has been called chaos. Hyperbolic systems are precisely defined dynamical systems that exhibit the properties ascribed to chaotic systems. In hyperbolic systems the tangent space perpendicular to a trajectory can be well separated into two parts: one with the points that converge towards the orbit (the stable manifold) and another of the points that diverge from the orbit (the unstable manifold).
Intuitive statistics Infant studies Intuitive_statistics > Evidence in humans > Infant studies An application of this view is the "sampling hypothesis," or the view that individual variation in children's causal and probabilistic inferences is an artifact of random sampling from a diverse set of hypotheses, and flexible generalizations based on sampling behavior and context. These views, particularly those advocating general Bayesian updating from specialized theories, are considered successors to Piaget's theory rather than wholesale refutations because they maintain its domain-generality, viewing children as randomly and unsystematically considering a range of models before selecting a probable conclusion.In contrast to the general-purpose mechanistic view, some researchers advocate both domain-specific information structures and similarly specialized inferential mechanisms.
Alkalinity Theoretical treatment Alkalinity > Theoretical treatment CO2−3 however, will consume two protons before becoming a zero-level species (CO2), thus it increases alkalinity by two per mole of CO2−3. and decrease alkalinity, as they act as sources of protons. They are often represented collectively as T. Alkalinity is typically reported as mg/L as CaCO3. (The conjunction "as" is appropriate in this case because the alkalinity results from a mixture of ions but is reported "as if" all of this is due to CaCO3.) This can be converted into milliequivalents per Liter (meq/L) by dividing by 50 (the approximate MW of CaCO3 divided by 2).
Skill assessment Reliability Skill_assessment > Principles of assessment > Reliability After validity, reliability is essential. A reliable assessment is one where the evidence elicited and interpretation of evidence is consistent with the skill required, so that the assessment consistently produces outcomes that are compliant with the standard. The assessment decision of a given observed performance should not vary for different assessors. The same evidence should lead to the same outcome.To achieve this, the assessment tool must provide sufficient guidance for the assessor. In practice the assessment instrument provided to the candidate should be paired with an assessor guide which provides instructions to the assessor to guide their judgement of satisfactory performance or acceptable answers to questions.
Adaptationist program Teleology Adaptationism > Purpose and function > Teleology On the other hand, biologists want to deny conscious purpose in evolution. The dilemma gave rise to a famous joke by the evolutionary biologist Haldane: "Teleology is like a mistress to a biologist: he cannot live without her but he's unwilling to be seen with her in public.'" David Hull commented that Haldane's mistress "has become a lawfully wedded wife. Biologists no longer feel obligated to apologize for their use of teleological language; they flaunt it. The only concession which they make to its disreputable past is to rename it 'teleonomy'."
Photovoltaic solar arrays Shading and dirt Solar_PV > Components > Solar array > Shading and dirt For example, a shaded cell may drop 8 volts, instead of adding 0.5 volts, at a high current level, thereby absorbing the power produced by 16 other cells. It is thus important that a PV installation not be shaded by trees or other obstructions. There are techniques to mitigate the losses with diodes, but these techniques also entail losses.
Your Favorite Gene Summary Your_Favorite_Gene Your Favorite Gene is a dynamic web-based research tool provided by Sigma-Aldrich Corp and powered by Ingenuity Systems' Knowledge Base, a repository of biological and chemical networks that is the largest database of its kind. Biological pathways, metabolic pathways, and gene interaction networks are available. The tool was initially released in 2007.
Symbolic artificial intelligence Heuristic search Symbolic_artificial_intelligence > History > The first AI summer: irrational exuberance, 1948–1966 > Heuristic search In addition to the highly-specialized domain-specific kinds of knowledge that we will see later used in expert systems, early symbolic AI researchers discovered another more general application of knowledge. These were called heuristics, rules of thumb that guide a search in promising directions: "How can non-enumerative search be practical when the underlying problem is exponentially hard? The approach advocated by Simon and Newell is to employ heuristics: fast algorithms that may fail on some inputs or output suboptimal solutions." Another important advance was to find a way to apply these heuristics that guarantees a solution will be found, if there is one, not withstanding the occasional fallibility of heuristics: "The A* algorithm provided a general frame for complete and optimal heuristically guided search. A* is used as a subroutine within practically every AI algorithm today but is still no magic bullet; its guarantee of completeness is bought at the cost of worst-case exponential time.
Glossary of environmental science R Glossary_of_environmental_science > R respiration – (biology) uptake by a living organism of oxygen from the air (or water) which is then used to oxidise organic matter or food. The outputs of this oxidation are usually CO2 and H2O; the metabolic process by which organisms meet their internal energy needs and release CO2.
Darcy's Law Summary Darcy's_Law Darcy's law is an equation that describes the flow of a fluid through a porous medium. The law was formulated by Henry Darcy based on results of experiments on the flow of water through beds of sand, forming the basis of hydrogeology, a branch of earth sciences. It is analogous to Ohm's law in electrostatics, linearly relating the volume flow rate of the fluid to the hydraulic head difference (which is often just proportional to the pressure difference) via the hydraulic conductivity.
Polar decomposition theorem Construction and proofs of existence Polar_decomposition_theorem > Construction and proofs of existence The core idea behind the construction of the polar decomposition is similar to that used to compute the singular-value decomposition.
Jump target (computing) Performance problems with branch instructions Unconditional_branch > Performance problems with branch instructions To achieve high performance, modern processors are pipelined. They consist of multiple parts that each partially process an instruction, feed their results to the next stage in the pipeline, and start working on the next instruction in the program. This design expects instructions to execute in a particular unchanging sequence. Conditional branch instructions make it impossible to know this sequence. So conditional branches can cause "stalls" in which the pipeline has to be restarted on a different part of the program.
Quantum engineering Summary Quantum_engineering Quantum engineering is the development of technology that capitalizes on the laws of quantum mechanics. Quantum engineering uses quantum mechanics as a toolbox for the development of quantum technologies, such as quantum sensors or quantum computers. There are many devices available which rely on quantum mechanical effects and have revolutionized society through medicine, optical communication, high-speed internet, and high-performance computing, just to mention a few examples.
Algebraic signal processing Summary Algebraic_signal_processing Algebraic signal processing (ASP) is an emerging area of theoretical signal processing (SP). In the algebraic theory of signal processing, a set of filters is treated as an (abstract) algebra, a set of signals is treated as a module or vector space, and convolution is treated as an algebra representation. The advantage of algebraic signal processing is its generality and portability.
Pressure-volume work Non-mechanical forms of work Work_(thermodynamics) > Non-mechanical forms of work Pressure–volume work is a kind of contact work, because it occurs through direct material contact with the surrounding wall or matter at the boundary of the system. It is accurately described by changes in state variables of the system, such as the time courses of changes in the pressure and volume of the system. The volume of the system is classified as a "deformation variable", and is properly measured externally to the system, in the surroundings.
Ohm's Law Microscopic origins Ohm's_Law > Microscopic origins The net result is that electrons take a zigzag path due to the collisions, but generally drift in a direction opposing the electric field. The drift velocity then determines the electric current density and its relationship to E and is independent of the collisions. Drude calculated the average drift velocity from p = −eEτ where p is the average momentum, −e is the charge of the electron and τ is the average time between the collisions. Since both the momentum and the current density are proportional to the drift velocity, the current density becomes proportional to the applied electric field; this leads to Ohm's law.
NADPH oxidase Pathology NADPH_oxidase > Pathology ROS produced by NADPH oxidase activate an enzyme that makes the macrophages adhere to the artery wall (by polymerizing actin fibers). This process is counterbalanced by NADPH oxidase inhibitors, and by antioxidants. An imbalance in favor of ROS produces atherosclerosis.
Beta limit Fusion basics Beta_(plasma_physics) > Background > Fusion basics Nuclear fusion occurs when the nuclei of two atoms approach closely enough for the nuclear force to pull them together into a single larger nucleus. The strong force is opposed by the electrostatic force created by the positive charge of the nuclei's protons, pushing the nuclei apart. The amount of energy that is needed to overcome this repulsion is known as the Coulomb barrier. The amount of energy released by the fusion reaction when it occurs may be greater or less than the Coulomb barrier.
Radiation length Summary Radiation_length In particle physics, the radiation length is a characteristic of a material, related to the energy loss of high energy particles electromagnetically interacting with it. It is defined as the mean length (in cm) into the material at which the energy of an electron is reduced by the factor 1/e.
Immune surveillance Helper T cells Immune_surveillance > Adaptive immune system > Cell mediated immunity > Helper T cells Helper T cells regulate both the innate and adaptive immune responses and help determine which immune responses the body makes to a particular pathogen. These cells have no cytotoxic activity and do not kill infected cells or clear pathogens directly. They instead control the immune response by directing other cells to perform these tasks.Helper T cells express T cell receptors that recognize antigen bound to Class II MHC molecules. The MHC:antigen complex is also recognized by the helper cell's CD4 co-receptor, which recruits molecules inside the T cell (such as Lck) that are responsible for the T cell's activation.
QED vacuum Electromagnetic properties QED_vacuum > Electromagnetic properties Under some extreme circumstances in which the field exceeds the Schwinger limit (for example, in the very high fields found in the exterior regions of pulsars), the quantum electrodynamic vacuum is thought to exhibit nonlinearity in the fields. Calculations also indicate birefringence and dichroism at high fields. Many of electromagnetic effects of the vacuum are small, and only recently have experiments been designed to enable the observation of nonlinear effects. PVLAS and other teams are working towards the needed sensitivity to detect QED effects.
Induction heating Summary Induction_heating The rapidly alternating magnetic field penetrates the object, generating electric currents inside the conductor called eddy currents. The eddy currents flow through the resistance of the material, and heat it by Joule heating. In ferromagnetic and ferrimagnetic materials, such as iron, heat also is generated by magnetic hysteresis losses. The frequency of the electric current used for induction heating depends on the object size, material type, coupling (between the work coil and the object to be heated), and the penetration depth.
Protein–lipid interaction Backbone and solid chain dynamics of membrane proteins Protein–lipid_interaction > Backbone and solid chain dynamics of membrane proteins Solid-state NMR techniques have the potential to yield detailed information about the dynamics of individual amino acid residues within a membrane protein. However, the techniques can require large amounts (100–200 mg) of isotopically labeled proteins and are most informative when applied to small proteins where spectroscopic assignments are possible.
Logical OR Set theory Logical_disjunction > Set theory The membership of an element of a union set in set theory is defined in terms of a logical disjunction: x ∈ A ∪ B ⇔ ( x ∈ A ) ∨ ( x ∈ B ) {\displaystyle x\in A\cup B\Leftrightarrow (x\in A)\vee (x\in B)} . Because of this, logical disjunction satisfies many of the same identities as set-theoretic union, such as associativity, commutativity, distributivity, and de Morgan's laws, identifying logical conjunction with set intersection, logical negation with set complement.
AC Power Transmission Load balancing Electric_power_transmission_grid > Control > Load balancing Voltage and frequency can be used as signaling mechanisms to balance the loads. In voltage signaling, voltage is varied to increase generation. The power added by any system increases as the line voltage decreases.
Transcendental equation Transformation into an algebraic equation Transcendental_equation > Transformation into an algebraic equation Ad hoc methods exist for some classes of transcendental equations in one variable to transform them into algebraic equations which then might be solved.
Cross-validation (statistics) Types Holdout_method > Types Two types of cross-validation can be distinguished: exhaustive and non-exhaustive cross-validation.
Computer simulations of fluids Background and history Computational_fluid_mechanics > Background and history The advantage of the lower order codes was that they ran much faster on the computers of the time. Today, VSAERO has grown to be a multi-order code and is the most widely used program of this class. It has been used in the development of many submarines, surface ships, automobiles, helicopters, aircraft, and more recently wind turbines.
Differential evolution Algorithm Differential_evolution > Algorithm A basic variant of the DE algorithm works by having a population of candidate solutions (called agents). These agents are moved around in the search-space by using simple mathematical formulae to combine the positions of existing agents from the population. If the new position of an agent is an improvement then it is accepted and forms part of the population, otherwise the new position is simply discarded. The process is repeated and by doing so it is hoped, but not guaranteed, that a satisfactory solution will eventually be discovered.
Tail-call optimization Summary Tail_recursive However, in functional programming languages, tail-call elimination is often guaranteed by the language standard, allowing tail recursion to use a similar amount of memory as an equivalent loop. The special case of tail-recursive calls, when a function calls itself, may be more amenable to call elimination than general tail calls. When the language semantics do not explicitly support general tail calls, a compiler can often still optimize sibling calls, or tail calls to functions which take and return the same types as the caller.
An Essay on the Principle of Population Social theory An_Essay_on_the_Principle_of_Population > Reception, criticism, and legacy of Essay > Social theory Despite use of the term "Malthusian catastrophe" by detractors such as economist Julian Simon (1932–1998), Malthus himself did not write that mankind faced an inevitable future catastrophe. Rather, he offered an evolutionary social theory of population dynamics as it had acted steadily throughout all previous history. Eight major points regarding population dynamics appear in the 1798 Essay: subsistence severely limits population-level when the means of subsistence increases, population increases population-pressures stimulate increases in productivity increases in productivity stimulate further population-growth because productivity increases cannot maintain the potential rate of population growth, population requires strong checks to keep parity with the carrying-capacity individual cost/benefit decisions regarding sex, work, and children determine the expansion or contraction of population and production checks will come into operation as population exceeds subsistence-level the nature of these checks will have significant effect on the larger sociocultural system—Malthus points specifically to misery, vice, and povertyMalthusian social theory influenced Herbert Spencer's idea of the survival of the fittest, and the modern ecological-evolutionary social theory of Gerhard Lenski and Marvin Harris.
Controlled airspace Summary Controlled_airspace Controlled airspace is airspace of defined dimensions within which air traffic control (ATC) services are provided. The level of control varies with different classes of airspace. Controlled airspace usually imposes higher weather minimums than are applicable in uncontrolled airspace. It is the opposite of uncontrolled airspace.
Wood-Anderson torsion seismometer Richter magnitude scale Wood–Anderson_seismometer > Richter magnitude scale Richter resolved some difficulties with this method and then, using data collected by his colleague Beno Gutenberg, he produced similar curves, confirming that they could be used to compare the relative magnitudes of different earthquakes.To produce a practical method of assigning an absolute measure of magnitude required additional developments. First, to span the wide range of possible values, Richter adopted Gutenberg's suggestion of a logarithmic scale, where each step represents a tenfold increase of magnitude, similar to the magnitude scale used by astronomers for star brightness.
Incidental music Loop Incidental_music > Types > Loop Short sequences of recorded music called loops are sometimes designed so that they can be repeated indefinitely and seamlessly as required to accompany visuals. These are often used as background music in documentary and trade films.
Ecological theory Modelling approaches Ecology_theory > Modelling approaches One class of computational models that is becoming increasingly popular are the agent-based models. These models can simulate the actions and interactions of multiple, heterogeneous, organisms where more traditional, analytical techniques are inadequate. Applied theoretical ecology yields results which are used in the real world. For example, optimal harvesting theory draws on optimization techniques developed in economics, computer science and operations research, and is widely used in fisheries.
Fitness training Classification Fitness_training > Classification Physical exercises are generally grouped into three types, depending on the overall effect they have on the human body: Aerobic exercise is any physical activity that uses large muscle groups and causes the body to use more oxygen than it would while resting. The goal of aerobic exercise is to increase cardiovascular endurance. Examples of aerobic exercise include running, cycling, swimming, brisk walking, skipping rope, rowing, hiking, dancing, playing tennis, continuous training, and long distance running. Anaerobic exercise, which includes strength and resistance training, can firm, strengthen, and increase muscle mass, as well as improve bone density, balance, and coordination.
Cell-cell recognition Bacterial ecology Cell–cell_recognition > Biological functions for extrinsic recognition > Bacterial ecology Single-celled organisms can bind to each other through surface receptors for cooperation and competition. This has been widely observed in bacteria. For instance, bacteria can attach to each other through the binding of outer membrane proteins TraA and TraB to facilitate a process called outer membrane exchange (OME) that allows bacterial cells to swap membrane lipids, sugars, and toxins.
Amoxicillin Pharmacology Amoxicillin > Pharmacology It has an onset of 30 minutes and a half-life of 3.7 hours in newborns and 1.4 hours in adults.Amoxicillin attaches to the cell wall of susceptible bacteria and results in their death. It also is a bactericidal compound. It is effective against streptococci, pneumococci, enterococci, Haemophilus influenzae, Escherichia coli, Proteus mirabilis, Neisseria meningitidis, Neisseria gonorrhoeae, Shigella, Chlamydia trachomatis, Salmonella, Borrelia burgdorferi, and Helicobacter pylori.
Proper velocity Comparing velocities at high speed Proper_velocity > Applications > Comparing velocities at high speed Proper velocity is useful for comparing the speed of objects with momentum per unit rest mass (w) greater than lightspeed c. The coordinate speed of such objects is generally near lightspeed, whereas proper velocity tells us how rapidly they are covering ground on traveling-object clocks. This is important for example if, like some cosmic ray particles, the traveling objects have a finite lifetime. Proper velocity also clues us in to the object's momentum, which has no upper bound. For example, a 45 GeV electron accelerated by the Large Electron–Positron Collider (LEP) at Cern in 1989 would have had a Lorentz factor γ of about 88,000 (45 GeV divided by the electron rest mass of 511 keV).
Dicke effect Mechanism Dicke_effect > Mechanism When the mean free path of an atom is much smaller than the wavelength of the radiative transition, the atom changes velocity and direction many times during the emission or absorption of a photon. This causes an averaging over different Doppler states and results in an atomic linewidth that is narrower than the Doppler width.
Deep Learning History Deep_neural_network > History The term Deep Learning was introduced to the machine learning community by Rina Dechter in 1986, and to artificial neural networks by Igor Aizenberg and colleagues in 2000, in the context of Boolean threshold neurons.In 1988, Wei Zhang et al. applied the backpropagation algorithm to a convolutional neural network (a simplified Neocognitron with convolutional interconnections between the image feature layers and the last fully connected layer) for alphabet recognition. They also proposed an implementation of the CNN with an optical computing system. In 1989, Yann LeCun et al. applied backpropagation to a CNN with the purpose of recognizing handwritten ZIP codes on mail.
Fungal prions [PIN+] / [RNQ+] Fungal_prions > Prions of yeast > [PIN+] / [RNQ+] The basis of the prion is an amyloid form of Rnq1 arranged in in-register parallel beta sheets, like the amyloid form of Sup35. Due to similar amyloid structures, the prion may facilitate the formation of through a templating mechanism.Two modified versions of Sup35 have been created that can induce PSI+ in the absence of when overexpressed. One version was created by digestion of the gene with the restriction enzyme Bal2, which results in a protein consisting of only the M and N portions of Sup35. The other is a fusion of Sup35NM with HPR, a human membrane receptor protein.
Khinchin integral Approximate derivative Khinchin_integral > Definition > Approximate derivative Let E be a Lebesgue measurable set of reals. Recall that a real number x (not necessarily in E) is said to be a point of density of E when lim ε → 0 μ ( E ∩ ) 2 ε = 1 {\displaystyle \lim _{\varepsilon \to 0}{\frac {\mu (E\cap )}{2\varepsilon }}=1} (where μ denotes Lebesgue measure). A Lebesgue-measurable function g: E → R is said to have approximate limit y at x (a point of density of E) if for every positive number ε, the point x is a point of density of g − 1 ( ) {\displaystyle g^{-1}()} . (If furthermore g(x) = y, we can say that g is approximately continuous at x.) Equivalently, g has approximate limit y at x if and only if there exists a measurable subset F of E such that x is a point of density of F and the (usual) limit at x of the restriction of f to F is y. Just like the usual limit, the approximate limit is unique if it exists. Finally, a Lebesgue-measurable function f: E → R is said to have approximate derivative y at x iff f ( x ′ ) − f ( x ) x ′ − x {\displaystyle {\frac {f(x')-f(x)}{x'-x}}} has approximate limit y at x; this implies that f is approximately continuous at x.
Selection theorem Preliminaries Selection_theorem > Preliminaries This is a special case of a choice function. The axiom of choice implies that a selection function always exists; however, it is often important that the selection have some "nice" properties, such as continuity or measurability. This is where the selection theorems come into action: they guarantee that, if F satisfies certain properties, then it has a selection f that is continuous or has other desirable properties.
Triphenylphosphine dichloride Structure Triphenylphosphine_dichloride > Structure In polar solvents such as acetonitrile, Ph3PCl2 adopts an ionic phosphonium salt structure, Cl−, whereas in non-polar solvents like diethyl ether it exists as a non-solvated trigonal bipyramidal molecule. Two species can also adopt an unusual dinuclear ionic structure—both interacting with a Cl− via long Cl–Cl contacts.
Two-dimensional polymers (2DP) Summary Two-dimensional_polymer A two-dimensional polymer (2DP) is a sheet-like monomolecular macromolecule consisting of laterally connected repeat units with end groups along all edges. This recent definition of 2DP is based on Hermann Staudinger's polymer concept from the 1920s. According to this, covalent long chain molecules ("Makromoleküle") do exist and are composed of a sequence of linearly connected repeat units and end groups at both termini. Moving from one dimension to two offers access to surface morphologies such as increased surface area, porous membranes, and possibly in-plane pi orbital-conjugation for enhanced electronic properties.
Tauroselcholic acid Development Tauroselcholic_acid > Development SeHCAT is a taurine-conjugated bile acid analog which was synthesized for use as a radiopharmaceutical to investigate in vivo the enterohepatic circulation of bile salts. By incorporating the gamma-emitter 75Se into the SeHCAT molecule, the retention in the body or the loss of this compound into the feces could be studied easily using a standard gamma camera, available in most clinical nuclear medicine departments.SeHCAT has been shown to be absorbed from the gut and excreted into the bile at the same rate as cholic acid, one of the major natural bile acids in humans. It undergoes secretion into the biliary tree, gallbladder and intestine in response to food, and is reabsorbed efficiently in the ileum, with kinetics similar to natural bile acids.
Etymology of electricity Entry into English Etymology_of_electricity > Historical drift > Entry into English The word electric was first used by Francis Bacon to describe materials like amber that attracted other objects. The first usage of the English word electricity is ascribed to Sir Thomas Browne in his 1646 work, Pseudodoxia Epidemica: Again, The concretion of Ice will not endure a dry attrition without liquation; for if it be rubbed long with a cloth, it melteth. But Crystal will calefie unto electricity; that is, a power to attract strawes and light bodies, and convert the needle freely placed In this context, an "Electrick" or "Electrick body" was a non-conductor, or an object capable of attracting "light bodies" (like bits of paper) when excited by friction; a piece of amber is "an Electrick", while a piece of iron is not. "Electricity", then, was simply the property of behaving like an electric, in the same way that "elasticity" is the property of behaving like an elastic. ("Electric" continued to be used as a noun until at least 1913 and is still used in this sense in the word "dielectric".) It was not until later that the definition shifted to refer to the cause of the attraction instead of the property of being attractive.Charge, in the electrical sense, was first used in 1748.
Warfarin sodium Interactions Warfarin_rodenticide > Interactions Warfarin interacts with many commonly used drugs, and the metabolism of warfarin varies greatly between patients. Some foods have also been reported to interact with warfarin. Apart from the metabolic interactions, highly protein bound drugs can displace warfarin from serum albumin and cause an increase in the INR. This makes finding the correct dosage difficult, and accentuates the need of monitoring; when initiating a medication that is known to interact with warfarin (e.g., simvastatin), INR checks are increased or dosages adjusted until a new ideal dosage is found.
Distributed representation Fully recurrent Types_of_artificial_neural_networks > Recurrent neural network > Fully recurrent For a training set of numerous sequences, the total error is the sum of the errors of all individual sequences. To minimize total error, gradient descent can be used to change each weight in proportion to its derivative with respect to the error, provided the non-linear activation functions are differentiable. The standard method is called "backpropagation through time" or BPTT, a generalization of back-propagation for feedforward networks.
Multidimensional discrete convolution Filtering on a helix Multidimensional_discrete_convolution > The helix transform > Filtering on a helix . . , 0 , − 1 , 4 , − 1 , 0 , .
Scientific methods Relationship with mathematics Scientific_studies > Relationship with mathematics In mathematics, a statement need not yet be proved; at such a stage, that statement would be called a conjecture. But when a statement has attained mathematical proof, that statement gains a kind of immortality which is highly prized by mathematicians, and for which some mathematicians devote their lives.Mathematical work and scientific work can inspire each other. For example, the technical concept of time arose in science, and timelessness was a hallmark of a mathematical topic.
Log-normal distribution Other Log-normal_distribution > Properties > Other A set of data that arises from the log-normal distribution has a symmetric Lorenz curve (see also Lorenz asymmetry coefficient).The harmonic H {\displaystyle H} , geometric G {\displaystyle G} and arithmetic A {\displaystyle A} means of this distribution are related; such relation is given by H = G 2 A . {\displaystyle H={\frac {G^{2}}{A}}.} Log-normal distributions are infinitely divisible, but they are not stable distributions, which can be easily drawn from.
Resistor-transistor logic One-transistor RTL NOR gate Resistor–transistor_logic > Implementation > One-transistor RTL NOR gate With two or more base resistors (R3 and R4) instead of one, the inverter becomes a two-input RTL NOR gate (see the figure on the right). The logical operation OR is performed by applying consecutively the two arithmetic operations addition and comparison (the input resistor network acts as a parallel voltage summer with equally weighted inputs and the following common-emitter transistor stage as a voltage comparator with a threshold about 0.7 V). The equivalent resistance of all the resistors connected to logical "1" and the equivalent resistance of all the resistors connected to logical "0" form the two legs of a composed voltage divider driving the transistor. The base resistances and the number of the inputs are chosen (limited) so that only one logical "1" is sufficient to create base-emitter voltage exceeding the threshold and, as a result, saturating the transistor.
Conjugate variables (thermodynamics) Pressure/volume and stress/strain pairs Thermodynamic_parameters > Pressure/volume and stress/strain pairs In the case of viscous fluids, plastic and elastic solids, the pressure force is generalized to the stress tensor, and changes in volume are generalized to the volume multiplied by the strain tensor. These then form a conjugate pair. If σ i j {\displaystyle \sigma _{ij}} is the ij component of the stress tensor, and ε i j {\displaystyle \varepsilon _{ij}} is the ij component of the strain tensor, then the mechanical work done as the result of a stress-induced infinitesimal strain ε i j {\displaystyle \mathrm {\varepsilon } _{ij}} is: δ w = V ∑ i j σ i j d ε i j {\displaystyle \delta w=V\sum _{ij}\sigma _{ij}\,\mathrm {d} \varepsilon _{ij}} or, using Einstein notation for the tensors, in which repeated indices are assumed to be summed: δ w = V σ i j d ε i j {\displaystyle \delta w=V\sigma _{ij}\,\mathrm {d} \varepsilon _{ij}} In the case of pure compression (i.e. no shearing forces), the stress tensor is simply the negative of the pressure times the unit tensor so that δ w = V ( − p δ i j ) d ε i j = − ∑ k p V d ε k k {\displaystyle \delta w=V\,(-p\delta _{ij})\,\mathrm {d} \varepsilon _{ij}=-\sum _{k}pV\,\mathrm {d} \varepsilon _{kk}} The trace of the strain tensor ( ε k k {\displaystyle \varepsilon _{kk}} ) is the fractional change in volume so that the above reduces to δ w = − p d V {\displaystyle \delta w=-p\mathrm {d} V} as it should.
Rotary power Relationship between torque, power, and energy Rotary_power > Relationship between torque, power, and energy If a force is allowed to act through a distance, it is doing mechanical work. Similarly, if torque is allowed to act through an angular displacement, it is doing work. Mathematically, for rotation about a fixed axis through the center of mass, the work W can be expressed as W = ∫ θ 1 θ 2 τ d θ , {\displaystyle W=\int _{\theta _{1}}^{\theta _{2}}\tau \ \mathrm {d} \theta ,} where τ is torque, and θ1 and θ2 represent (respectively) the initial and final angular positions of the body.
Action at a distance Einstein Action_at_a_distance > Gravity > Einstein According to Albert Einstein's theory of special relativity, instantaneous action at a distance violates the relativistic upper limit on speed of propagation of information. If one of the interacting objects were to suddenly be displaced from its position, the other object would feel its influence instantaneously, meaning information had been transmitted faster than the speed of light.One of the conditions that a relativistic theory of gravitation must meet is that gravity is mediated with a speed that does not exceed c, the speed of light in vacuum. From the previous success of electrodynamics, it was foreseeable that the relativistic theory of gravitation would have to use the concept of a field, or something similar.This has been achieved by Einstein's theory of general relativity, in which gravitational interaction is mediated by deformation of space-time geometry. Matter warps the geometry of space-time, and these effects are—as with electric and magnetic fields—propagated at the speed of light.
Quantum binary digit Applications Pure_qubit_state > Quantum entanglement > Applications The | Φ + ⟩ {\displaystyle |\Phi ^{+}\rangle } Bell state forms part of the setup of the superdense coding, quantum teleportation, and entangled quantum cryptography algorithms. Quantum entanglement also allows multiple states (such as the Bell state mentioned above) to be acted on simultaneously, unlike classical bits that can only have one value at a time. Entanglement is a necessary ingredient of any quantum computation that cannot be done efficiently on a classical computer. Many of the successes of quantum computation and communication, such as quantum teleportation and superdense coding, make use of entanglement, suggesting that entanglement is a resource that is unique to quantum computation. A major hurdle facing quantum computing, as of 2018, in its quest to surpass classical digital computing, is noise in quantum gates that limits the size of quantum circuits that can be executed reliably.
X86 memory segmentation Later developments X86_memory_segmentation > Later developments Unlike the global descriptor table mechanism used by legacy modes, the base address of these segments is stored in a model-specific register. The x86-64 architecture further provides the special SWAPGS instruction, which allows swapping the kernel mode and user mode base addresses. For instance, Microsoft Windows on x86-64 uses the GS segment to point to the Thread Environment Block, a small data structure for each thread, which contains information about exception handling, thread-local variables, and other per-thread state. Similarly, the Linux kernel uses the GS segment to store per-CPU data. GS/FS are also used in gcc's thread-local storage and canary-based stack protector.
Albion process Chemistry Albion_process > Chemistry The general reaction for the leaching process is: M S 2 + 1 2 O 2 + H 2 S O 4 → M S O 4 + S 0 + H 2 O {\displaystyle MS_{2}+{\frac {1}{2}}O_{2}+H_{2}SO_{4}\rightarrow MSO_{4}+S^{0}+H_{2}O} == References ==
Karl Weierstrass Soundness of calculus Karl_Weierstrass > Mathematical contributions > Soundness of calculus Weierstrass was interested in the soundness of calculus, and at the time there were somewhat ambiguous definitions of the foundations of calculus so that important theorems could not be proven with sufficient rigour. Although Bolzano had developed a reasonably rigorous definition of a limit as early as 1817 (and possibly even earlier) his work remained unknown to most of the mathematical community until years later, and many mathematicians had only vague definitions of limits and continuity of functions. The basic idea behind Delta-epsilon proofs is, arguably, first found in the works of Cauchy in the 1820s. Cauchy did not clearly distinguish between continuity and uniform continuity on an interval.
Kammback Aerodynamic theory Kammback > Aerodynamic theory The Kammback presented a partial solution to the problem of aerodynamic lift, which was becoming severe as sports car racing speeds increased during the 1950s. The design paradigm of sloping the tail to reduce drag was carried to an extreme on cars such as the Cunningham C-5R, resulting in an airfoil effect lifting the rear of the car at speed and so running the risk of instability or loss of control. The Kammback decreased the area of the lifting surface while creating a low-pressure zone underneath the tail. Some studies showed that the addition of a rear spoiler to a Kammback design was not beneficial because the overall drag increased with the angles that were studied.
Binary fission Binary fission Binary_fission > Binary fission Organisms in the domains of Archaea and Bacteria reproduce with binary fission. This form of asexual reproduction and cell division is also used by some organelles within eukaryotic organisms (e.g., mitochondria). Binary fission results in the reproduction of a living prokaryotic cell (or organelle) by dividing the cell into two parts, each with the potential to grow to the size of the original.
Indium gallium arsenide antimonide Efficiency Indium_gallium_arsenide_antimonide > Details > Efficiency The upper limit for efficiency in TPVs (and all systems that convert heat energy to work) is the Carnot efficiency, that of an ideal heat engine. This efficiency is given by: η = 1 − T c e l l T e m i t {\displaystyle \eta =1-{\frac {T_{cell}}{T_{emit}}}} where Tcell is the temperature of the PV converter. Practical systems can achieve Tcell= ~300 K and Temit= ~1800 K, giving a maximum possible efficiency of ~83%.
Pancreatic amylase Summary Amylase An amylase () is an enzyme that catalyses the hydrolysis of starch (Latin amylum) into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion. Foods that contain large amounts of starch but little sugar, such as rice and potatoes, may acquire a slightly sweet taste as they are chewed because amylase degrades some of their starch into sugar. The pancreas and salivary gland make amylase (alpha amylase) to hydrolyse dietary starch into disaccharides and trisaccharides which are converted by other enzymes to glucose to supply the body with energy.
Coefficient of Performance Equation Coefficient_of_Performance > Equation The equation is: C O P = | Q | W {\displaystyle {\rm {COP}}={\frac {|Q|}{W}}} where Q {\displaystyle Q\ } is the useful heat supplied or removed by the considered system (machine). W > 0 {\displaystyle W>0\ } is the net work put into the considered system in one cycle.The COP for heating and cooling are different because the heat reservoir of interest is different. When one is interested in how well a machine cools, the COP is the ratio of the heat taken up from the cold reservoir to input work. However, for heating, the COP is the ratio of the magnitude of the heat given off to the hot reservoir (which is the heat taken up from the cold reservoir plus the input work) to the input work: C O P c o o l i n g = | Q C | W = Q C W {\displaystyle {\rm {COP}}_{\rm {cooling}}={\frac {|Q_{\rm {C}}|}{W}}={\frac {Q_{\rm {C}}}{W}}} C O P h e a t i n g = | Q H | W = Q C + W W = C O P c o o l i n g + 1 {\displaystyle {\rm {COP}}_{\rm {heating}}={\frac {|Q_{\rm {H}}|}{W}}={\frac {Q_{\rm {C}}+W}{W}}={\rm {COP}}_{\rm {cooling}}+1} where Q C > 0 {\displaystyle Q_{\rm {C}}>0\ } is the heat removed from the cold reservoir and added to the system; Q H < 0 {\displaystyle Q_{\rm {H}}<0\ } is the heat given off to the hot reservoir; it is lost by the system and therefore negative (see heat).Note that the COP of a heat pump depends on its direction. The heat rejected to the hot sink is greater than the heat absorbed from the cold source, so the heating COP is greater by one than the cooling COP.
Diné Bahaneʼ Birth of the Twins Diné_Bahaneʼ > The Fourth World > The Monster Slayer Twins > Birth of the Twins Soon after that, Changing Woman wished for a mate. Every morning when the sun rose she lay on her back until noon, her head to the west and her feet to the east. At noon she went to the spring. She lay under the ledge and let spring water drip over her body.
Linear Algebra Subspaces, span, and basis Linear_Algebra > Vector spaces > Subspaces, span, and basis For example, given a linear map T: V → W, the image T(V) of V, and the inverse image T−1(0) of 0 (called kernel or null space), are linear subspaces of W and V, respectively. Another important way of forming a subspace is to consider linear combinations of a set S of vectors: the set of all sums a 1 v 1 + a 2 v 2 + ⋯ + a k v k , {\displaystyle a_{1}\mathbf {v} _{1}+a_{2}\mathbf {v} _{2}+\cdots +a_{k}\mathbf {v} _{k},} where v1, v2, ..., vk are in S, and a1, a2, ..., ak are in F form a linear subspace called the span of S. The span of S is also the intersection of all linear subspaces containing S. In other words, it is the smallest (for the inclusion relation) linear subspace containing S. A set of vectors is linearly independent if none is in the span of the others. Equivalently, a set S of vectors is linearly independent if the only way to express the zero vector as a linear combination of elements of S is to take zero for every coefficient ai.
History of Maxwell's equations Summary History_of_Maxwell's_equations In the beginning of the 19th century, many experimental and theoretical works had been accomplished in the understanding of electromagnetics. In the 1780s, Coulomb's law of electrostatics had been established. In 1825, Ampère published his Ampère's law.
Finitely presented algebra C Glossary_of_ring_theory > C A central algebra is an associative algebra over the center. 3. A central simple algebra is a central algebra that is also a simple ring.
Normal derivative Summary Directional_derivative A directional derivative is a concept in multivariable calculus that measures the rate at which a function changes in a particular direction at a given point.The directional derivative of a multivariable differentiable (scalar) function along a given vector v at a given point x intuitively represents the instantaneous rate of change of the function, moving through x with a velocity specified by v. The directional derivative of a scalar function f with respect to a vector v at a point (e.g., position) x may be denoted by any of the following: It therefore generalizes the notion of a partial derivative, in which the rate of change is taken along one of the curvilinear coordinate curves, all other coordinates being constant. The directional derivative is a special case of the Gateaux derivative.
Simply laced Dynkin diagram Related classifications Affine_Dynkin_diagram > Related classifications Dynkin diagrams can be interpreted as classifying many distinct, related objects, and the notation "An, Bn, ..." is used to refer to all such interpretations, depending on context; this ambiguity can be confusing. The central classification is that a simple Lie algebra has a root system, to which is associated an (oriented) Dynkin diagram; all three of these may be referred to as Bn, for instance. The unoriented Dynkin diagram is a form of Coxeter diagram, and corresponds to the Weyl group, which is the finite reflection group associated to the root system. Thus Bn may refer to the unoriented diagram (a special kind of Coxeter diagram), the Weyl group (a concrete reflection group), or the abstract Coxeter group.
Reich Technologies Profile Reich_Technologies > Profile Reich Technologies is an international group of companies, providing a coordinated suite of products and services to support object-oriented (OO) software development in large corporations. With a presence throughout Europe and North America, Reich Technologies occupies leading positions in the world markets for integrated OO CASE tools, fine-grained object repositories and OO team programming environments. The Intelligent Software Factory (ISF) offers an integrated object-oriented CASE tool suite. It is built on the concept of model-driven development in which the work done at the beginning of a project creates an environment for configuration management and cost containment for software maintenance.
Solvation Solvation energy and thermodynamic considerations Solvation > Solvation energy and thermodynamic considerations Enthalpy of solvation can help explain why solvation occurs with some ionic lattices but not with others. The difference in energy between that which is necessary to release an ion from its lattice and the energy given off when it combines with a solvent molecule is called the enthalpy change of solution. A negative value for the enthalpy change of solution corresponds to an ion that is likely to dissolve, whereas a high positive value means that solvation will not occur.
Insertion Sort Best, worst, and average cases Binary_insertion_sort > Best, worst, and average cases The set of all worst case inputs consists of all arrays where each element is the smallest or second-smallest of the elements before it. In these cases every iteration of the inner loop will scan and shift the entire sorted subsection of the array before inserting the next element. This gives insertion sort a quadratic running time (i.e., O(n2)).
List of physics mnemonics Gibbs's free energy formula List_of_physics_mnemonics > Thermodynamics > Gibbs's free energy formula "Good Honey Tastes Sweet": (delta)G = H - T(delta)S.
Interprocedural optimization Analysis Link-time_optimization > Analysis This simple optimization is foiled the moment that the implementation of F(x) becomes impure; that is, its execution involves reference to parameters other than the explicit argument 6 that have been changed between the invocations, or side effects such as printing some message to a log, counting the number of evaluations, accumulating the CPU time consumed, preparing internal tables so that subsequent invocations for related parameters will be facilitated, and so forth. Losing these side effects via non-evaluation a second time may be acceptable, or they may not. More generally, aside from optimization, the second reason to use procedures is to avoid duplication of code that would produce the same results, or almost the same results, each time the procedure is performed. A general approach to optimization would therefore be to reverse this: some or all invocations of a certain procedure are replaced by the respective code, with the parameters appropriately substituted. The compiler will then try to optimize the result.
Factorion Definition Factorion > Definition = 1 ! = 1 {\displaystyle 0!=1!=1} . A natural number n {\displaystyle n} is a sociable factorion if it is a periodic point for SFD b {\displaystyle \operatorname {SFD} _{b}} , where SFD b k ⁡ ( n ) = n {\displaystyle \operatorname {SFD} _{b}^{k}(n)=n} for a positive integer k {\displaystyle k} , and forms a cycle of period k {\displaystyle k} .
Ethical AI Biases in AI systems AI_ethics > Ethical challenges > Biases in AI systems Process mining can be an important tool for organizations to achieve compliance with proposed AI regulations by identifying errors, monitoring processes, identifying potential root causes for improper execution, and other functions.The problem of bias in machine learning is likely to become more significant as the technology spreads to critical areas like medicine and law, and as more people without a deep technical understanding are tasked with deploying it. Some experts warn that algorithmic bias is already pervasive in many industries and that almost no one is making an effort to identify or correct it. There are some open-sourced tools by civil societies that are looking to bring more awareness to biased AI.
Luzin space In real analysis Luzin_space > In real analysis In real analysis and descriptive set theory, a Luzin set (or Lusin set), is defined as an uncountable subset A of the reals such that every uncountable subset of A is nonmeager; that is, of second Baire category. Equivalently, A is an uncountable set of reals that meets every first category set in only countably many points. Luzin proved that, if the continuum hypothesis holds, then every nonmeager set has a Luzin subset. Obvious properties of a Luzin set are that it must be nonmeager (otherwise the set itself is an uncountable meager subset) and of measure zero, because every set of positive measure contains a meager set that also has positive measure, and is therefore uncountable.
Software analysis Program slicing Program_analysis_(computer_science) > Dynamic program analysis > Program slicing For a given subset of a program’s behavior, program slicing consists of reducing the program to the minimum form that still produces the selected behavior. The reduced program is called a “slice” and is a faithful representation of the original program within the domain of the specified behavior subset. Generally, finding a slice is an unsolvable problem, but by specifying the target behavior subset by the values of a set of variables, it is possible to obtain approximate slices using a data-flow algorithm. These slices are usually used by developers during debugging to locate the source of errors.
Jacobson/Karels algorithm Other TCP congestion avoidance algorithms TCP_congestion_control > Algorithms > Other TCP congestion avoidance algorithms iTCP additionally enables advanced applications to directly participate in congestion control such as to control the source generation rate. Zeta-TCP detects congestion from both latency and loss rate measures. To maximize the goodput Zeta-TCP and applies different congestion window backoff strategies based on the likelihood of congestion. It also has other improvements to accurately detect packet losses, avoiding retransmission timeout retransmission; and accelerate and control the inbound (download) traffic.
Planck spectrum Cavity with a hole Black_body > Realizations > Cavity with a hole In 1898, Otto Lummer and Ferdinand Kurlbaum published an account of their cavity radiation source. Their design has been used largely unchanged for radiation measurements to the present day. It was a hole in the wall of a platinum box, divided by diaphragms, with its interior blackened with iron oxide.
Wing loading Summary Span_loading The airplane’s wing loading partly determines the takeoff speed and landing speed. A higher wing loading also decreases maneuverability. The same constraints apply to winged biological organisms.
DNS cache Authoritative name server Name_server > Domain name server > Authoritative name server Examples of such mechanisms include DNS zone transfers and file transfer protocols. DNS provides a mechanism whereby the primary for a zone can notify all the known secondaries for that zone when the contents of the zone have changed. The contents of a zone are either manually configured by an administrator, or managed using Dynamic DNS.Every domain name appears in a zone served by one or more authoritative name servers.
NEAT Particles Method NEAT_Particles > Method In NEAT Particles, each particle system is controlled by a Compositional pattern-producing network (CPPN), a type of artificial neural network, or ANN. In other words, the usually hand-coded 'rules' of a particle system are replaced by automatically generated CPPNs. The CPPNs are evolved and complexified by NeuroEvolution of Augmenting Topologies (NEAT). A simple, interactive evolutionary computation (IEC) interface enables user guided evolution. In this manner increasingly complex particle system effects are evolved by user preference.
Circle graph Summary Circle_graph In graph theory, a circle graph is the intersection graph of a chord diagram. That is, it is an undirected graph whose vertices can be associated with a finite system of chords of a circle such that two vertices are adjacent if and only if the corresponding chords cross each other.
Computer-aided industrial design Summary Computer-aided_industrial_design CAID programs tend to offer more tools that allow a designer to freely express themselves with more organic shapes and complex curves, whilst CAD software tends to be more focused on tools for the simple curves and straight lines more suitable for easy manufacturing. CAD implementations have evolved dramatically since initial 3D offerings in the 1970s, which were typically limited to producing drawings similar to hand-drafted output. Advances in programming and computer hardware, notably solid modelling in the 1980s, have allowed more versatile applications of computers in design activities.
Light day Use in astronomy Light_day > Use in astronomy The average distance between Earth and the Moon (the lunar distance) is about 1.282 light-seconds. The diameter of the Sun is about 4.643 light-seconds. The average distance between Earth and the Sun (the astronomical unit) is 499.0 light-seconds.Multiples of the light-second can be defined, although apart from the light-year, they are more used in popular science publications than in research works.
Residue class Summary Congruence_modulo_m If the time is 7:00 now, then 8 hours later it will be 3:00. Simple addition would result in 7 + 8 = 15, but clocks "wrap around" every 12 hours. Because the hour number starts over at zero when it reaches 12, this is arithmetic modulo 12. In terms of the definition below, 15 is congruent to 3 modulo 12, so "15:00" on a 24-hour clock is displayed "3:00" on a 12-hour clock.
Biopreservation Bacteriophages Biopreservation > Biopreservative agents and modes of action > Bacteriophages Bacteriophages are ubiquitously distributed in nature and can also be isolated from human or animal associated microflora. They outnumber their bacterial host species by a factor of ten representing the most abundant self-replicating entities on earth with an estimated 1031 phages in total.
Total complement activity CH50 Interpretation Total_complement_activity > Tests > CH50 Interpretation If an individual has deficient or malfunctioning complement factors, then at a baseline they have decreased capacity to lyse the erythrocytes. Therefore, any dilution to their serum would further impair this functioning, meaning that a lower dilution needs to be reached to achieve 50% capacity. In contrast, any individual with increased complement levels or activity would have an elevated CH50 since increasing dilution would be necessary to reach the 50% lyse marking. Decreased CH50 values may be seen in cirrhosis or hepatitis as a result of impaired complement production in the liver.
Galilei-covariant tensor formulation Bargmann structures Galilei-covariant_tensor_formulation > Bargmann structures In 1985 Duval, Burdet and Kunzle showed that four-dimensional Newton–Cartan theory of gravitation can be reformulated as Kaluza–Klein reduction of five-dimensional Einstein gravity along a null-like direction. The metric used is the same as the Galilean metric but with all positive entries g μ ν = ( 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 1 0 ) . {\displaystyle g^{\mu \nu }={\begin{pmatrix}1&0&0&0&0\\0&1&0&0&0\\0&0&1&0&0\\0&0&0&0&1\\0&0&0&1&0\end{pmatrix}}.} This lifting is considered to be useful for non-relativistic holographic models. Gravitational models in this framework have been shown to precisely calculate the mercury precession.
Lugiato–Lefever equation Quantum aspects Lugiato–Lefever_equation > Quantum aspects The two photons that, as shown in Fig.4, are emitted in symmetrically tilted directions in the FWM process, are in a state of quantum entanglement: they are precisely correlated, for example in energy and momentum. This fact is fundamental for the quantum aspects of optical patterns. For instance, the difference between the intensities of the two symmetrical beams is squeezed, i.e. exhibits fluctuations below the shot noise level; the longitudinal analogue of this phenomenon has been observed experimentally in KFC. In turn, such quantum aspects are basic for the field of quantum imaging.
Eicosanoid metabolism The ω-3 and ω-6 series Eicosanoid_metabolism > The ω-3 and ω-6 series National Institutes of Health and the National Library of Medicine state that there is 'A' level evidence that increased dietary ω-3 improves outcomes in hypertriglyceridemia, secondary cardiovascular disease prevention, and hypertension. There is 'B' level evidence ('good scientific evidence') for increased dietary ω-3 in primary prevention of cardiovascular disease, rheumatoid arthritis, and protection from ciclosporin toxicity in organ transplant patients. They also note more preliminary evidence showing that dietary ω-3 can ease symptoms in several psychiatric disorders.Besides the influence on eicosanoids, dietary polyunsaturated fats modulate immune response through three other molecular mechanisms. They (a) alter membrane composition and function, including the composition of lipid rafts; (b) change cytokine biosynthesis; and (c) directly activate gene transcription. Of these, the action on eicosanoids is the best explored.