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Effective results in number theory Littlewood's result Effective_results_in_number_theory > Littlewood's result A special case is to find the first sign change. The interest of the question was that the numerical evidence known showed no change of sign: Littlewood's result guaranteed that this evidence was just a small number effect, but 'small' here included values of n up to a billion. The requirement of computability reflects on and contrasts with the approach used in analytic number theory to prove the results.
Horizontal stabiliser Control Horizontal_stabilizer > Control A tailplane usually has some means allowing the pilot to control the amount of lift produced by the tailplane. This in turn causes a nose-up or nose-down pitching moment on the aircraft, which is used to control the aircraft in pitch. Elevator: A conventional tailplane normally has a hinged aft surface called an elevator, Stabilator or all-moving tail: In transonic flight shock waves generated by the front of the tailplane render any elevator unusable.
Ordered partition of a set Representation by functions Transitivity_of_incomparability > Axiomatizations > Representation by functions It is not assumed here that f {\displaystyle f} is an injective function, so a class of two equivalent elements on Y {\displaystyle Y} may induce a larger class of equivalent elements on X . {\displaystyle X.} Also, f {\displaystyle f} is not assumed to be a surjective function, so a class of equivalent elements on Y {\displaystyle Y} may induce a smaller or empty class on X .
Inductive coupling Summary Inductive_coupling Coupling may be intentional or unintentional. Unintentional inductive coupling can cause signals from one circuit to be induced into a nearby circuit, this is called cross-talk, and is a form of electromagnetic interference.
Electrical generators Power station Electric_generators > Common use cases > Power station The energy source harnessed to turn the generator varies widely. Most power stations in the world burn fossil fuels such as coal, oil, and natural gas to generate electricity. Cleaner sources include nuclear power, and increasingly used renewables such as the sun, wind, waves and running water.
Freiling's axiom of symmetry Objections to Freiling's argument Freiling's_axiom_of_symmetry > Objections to Freiling's argument Freiling's argument is not widely accepted because of the following two problems with it (which Freiling was well aware of and discussed in his paper). The naive probabilistic intuition used by Freiling tacitly assumes that there is a well-behaved way to associate a probability to any subset of the reals. But the mathematical formalization of the notion of probability uses the notion of measure, yet the axiom of choice implies the existence of non-measurable subsets, even of the unit interval. Some examples of this are the Banach–Tarski paradox and the existence of Vitali sets.
Tolman electronic parameter Other ligand electronic parameters Tolman_electronic_parameter > Other ligand electronic parameters Several other scales have been proposed for the ranking of the donor properties of ligands. The HEP scale ranks ligands on the basis of the 13C NMR shift of a reference ligand. Lever's electronic parameter ranking is related to the Ru(II/III) couple. Another scale evaluated ligands on the basis of the redox couples of 0/+.In a treatment akin to the TEP analysis, the donor properties of N-heterocyclic carbene (NHC) ligands have been ranked according to IR data recorded on cis- complexes.
Earthquake prediction Changes in Vp/Vs Earthquake_prediction > Prediction methods > Precursors > Changes in Vp/Vs Vp is the symbol for the velocity of a seismic "P" (primary or pressure) wave passing through rock, while Vs is the symbol for the velocity of the "S" (secondary or shear) wave. Small-scale laboratory experiments have shown that the ratio of these two velocities – represented as Vp/Vs – changes when rock is near the point of fracturing. In the 1970s it was considered a likely breakthrough when Russian seismologists reported observing such changes (later discounted.) in the region of a subsequent earthquake.
Generalized Stokes theorem In electromagnetism Stokes'_Theorem > Special cases > Green's theorem > In electromagnetism Two of the four Maxwell equations involve curls of 3-D vector fields, and their differential and integral forms are related by the special 3-dimensional (vector calculus) case of Stokes' theorem. Caution must be taken to avoid cases with moving boundaries: the partial time derivatives are intended to exclude such cases. If moving boundaries are included, interchange of integration and differentiation introduces terms related to boundary motion not included in the results below (see Differentiation under the integral sign): The above listed subset of Maxwell's equations are valid for electromagnetic fields expressed in SI units. In other systems of units, such as CGS or Gaussian units, the scaling factors for the terms differ. For example, in Gaussian units, Faraday's law of induction and Ampère's law take the forms: respectively, where c is the speed of light in vacuum.
Electroplasticity Summary Electroplasticity Electroplasticity, describes the enhanced plastic behavior of a solid material under the application of an electric field. This electric field could be internal, resulting in current flow in conducting materials, or external. The effect of electric field on mechanical properties ranges from simply enhancing existing plasticity, such as reducing the flow stress in already ductile metals, to promoting plasticity in otherwise brittle ceramics.
166 (number) In other fields 166_(number) > In other fields 166 is also: The year AD 166 or 166 BC The atomic number of an element temporarily called Unhexhexium
Vibration fatigue Summary Vibration_fatigue Vibration fatigue is a mechanical engineering term describing material fatigue, caused by forced vibration of random nature. An excited structure responds according to its natural-dynamics modes, which results in a dynamic stress load in the material points. The process of material fatigue is thus governed largely by the shape of the excitation profile and the response it produces. As the profiles of excitation and response are preferably analyzed in the frequency domain it is practical to use fatigue life evaluation methods, that can operate on the data in frequency-domain, s power spectral density (PSD).
Pie graph Square chart / Waffle chart Sunburst_diagram > Variants and similar charts > Square chart / Waffle chart Square charts, also called waffle charts, are a form of pie charts that use squares instead of circles to represent percentages. Similar to basic circular pie charts, square pie charts take each percentage out of a total 100%. They are often 10 by 10 grids, where each cell represents 1%. Despite the name, circles, pictograms (such as of people), and other shapes may be used instead of squares. One major benefit to square charts is that smaller percentages, difficult to see on traditional pie charts, can be easily depicted.
Nuclear fission products Yield Fission_products > Yield For instance, the curve of yield against mass for 239Pu has a more shallow valley than that observed for 235U when the neutrons are thermal neutrons. The curves for the fission of the later actinides tend to make even more shallow valleys. In extreme cases such as 259Fm, only one peak is seen; this is a consequence of symmetric fission becoming dominant due to shell effects.The adjacent figure shows a typical fission product distribution from the fission of uranium.
Behavioural game theory Learning Behavioral_game_theory > Factors that affect rationality in games > Learning Reinforcement learning suggests that if a player received a high reward from choosing a certain behavior or strategy, then that player would be more inclined to use the same strategy again. If a particular strategy has not been used before however, then the strategy would not appear to be more or less appealing to the player. Another learning model is belief learning.
Image sensor format Shot noise Sensor_size > Sensor size, noise and dynamic range > Shot noise In the above equation, the shot noise SNR is given by P Q e t P Q e t = P Q e t {\displaystyle {\frac {PQ_{e}t}{\sqrt {PQ_{e}t}}}={\sqrt {PQ_{e}t}}} .Apart from the quantum efficiency it depends on the incident photon flux and the exposure time, which is equivalent to the exposure and the sensor area; since the exposure is the integration time multiplied with the image plane illuminance, and illuminance is the luminous flux per unit area. Thus for equal exposures, the signal to noise ratios of two different size sensors of equal quantum efficiency and pixel count will (for a given final image size) be in proportion to the square root of the sensor area (or the linear scale factor of the sensor). If the exposure is constrained by the need to achieve some required depth of field (with the same shutter speed) then the exposures will be in inverse relation to the sensor area, producing the interesting result that if depth of field is a constraint, image shot noise is not dependent on sensor area. For identical f-number lenses the signal to noise ratio increases as square root of the pixel area, or linearly with pixel pitch.
Neural net Use Criticism_of_artificial_neural_networks > Use Classification, including pattern and sequence recognition, novelty detection and sequential decision making. Data processing, including filtering, clustering, blind source separation and compression. Robotics, including directing manipulators and prostheses.
Telomere resolvase Summary Telomere_resolvase Telomere resolvase, also known as protelomerase, is an enzyme found in bacteria which contain linear plasmids.
Segmental bridge Construction Segmental_bridge > Construction In cast-in-place bridges, the falsework is connected to the previously installed concrete and allowed to cantilever freely. Next, the permanent reinforcing steel and supports are installed. Finally, the concrete is placed and cured, freeing the falsework to be moved.
Glossary of genetics (0–L) D Glossary_of_genetics_(0–L) > D DNA polymerase Any of a class of enzymes that synthesizes DNA molecules from individual deoxyribonucleotides. DNA polymerases are essential for DNA replication and usually work in pairs to create identical copies of the two strands of an original double-stranded molecule. They build long chains of DNA by adding nucleotides one at a time to the 3'-end of a DNA strand, usually relying on the template provided by the complementary strand to copy the nucleotide sequence faithfully.
Endocrinology Diseases Endocrinology > Diseases and medicine > Diseases See main article at Endocrine diseasesEndocrinology also involves the study of the diseases of the endocrine system. These diseases may relate to too little or too much secretion of a hormone, too little or too much action of a hormone, or problems with receiving the hormone.
Techniques of genetic engineering Choosing target genes Techniques_of_genetic_engineering > Choosing target genes Due to these insecticidal properties, the bacteria was used as a biological insecticide, developed commercially in 1938. The cry proteins were discovered to provide the insecticidal activity in 1956, and by the 1980s, scientists had successfully cloned the gene that encodes this protein and expressed it in plants. The gene that provides resistance to the herbicide glyphosate was found after seven years of searching in bacteria living in the outflow pipe of a Monsanto RoundUp manufacturing facility. In animals, the majority of genes used are growth hormone genes.
Double-ended queue Real-time deques via lazy rebuilding and scheduling Double-ended_queue > Implementations > Purely functional implementation > Real-time deques via lazy rebuilding and scheduling However, they use the invariant, in that if the front is empty then the rear has at most one element. The operations affecting the rear of the list are defined similarly by symmetry. It remains to explain how to define a method balance that rebalance the deque if insert' or tail broke the invariant.
Variance Moment of inertia Variance_generalizations > Moment of inertia The variance of a probability distribution is analogous to the moment of inertia in classical mechanics of a corresponding mass distribution along a line, with respect to rotation about its center of mass. It is because of this analogy that such things as the variance are called moments of probability distributions. The covariance matrix is related to the moment of inertia tensor for multivariate distributions. The moment of inertia of a cloud of n points with a covariance matrix of Σ {\displaystyle \Sigma } is given by I = n ( 1 3 × 3 tr ⁡ ( Σ ) − Σ ) .
On the Origin of Species Variation and heredity On_the_Origin_of_Species > Content > Variation and heredity Breeding of animals and plants showed related varieties varying in similar ways, or tending to revert to an ancestral form, and similar patterns of variation in distinct species were explained by Darwin as demonstrating common descent. He recounted how Lord Morton's mare apparently demonstrated telegony, offspring inheriting characteristics of a previous mate of the female parent, and accepted this process as increasing the variation available for natural selection.More detail was given in Darwin's 1868 book on The Variation of Animals and Plants Under Domestication, which tried to explain heredity through his hypothesis of pangenesis. Although Darwin had privately questioned blending inheritance, he struggled with the theoretical difficulty that novel individual variations would tend to blend into a population.
Fish reproduction Parthenogenesis Fish_reproduction > Reproductive strategies > Parthenogenesis Parthenogenesis is a form of asexual reproduction in which growth and development of embryos occur without fertilization. In animals, parthenogenesis means development of an embryo from an unfertilized egg cell. The first all-female (unisexual) reproduction in vertebrates was described in the Amazon molly in 1932. Since then at least 50 species of unisexual vertebrate have been described, including at least 20 fish, 25 lizards, a single snake species, frogs, and salamanders.
Format-preserving encryption Algorithms Format-preserving_encryption > Algorithms In most of the approaches listed here, a well-understood block cipher (such as AES) is used as a primitive to take the place of an ideal random function. This has the advantage that incorporation of a secret key into the algorithm is easy. Where AES is mentioned in the following discussion, any other good block cipher would work as well.
Standard logistic function In medicine: modeling of growth of tumors Verhulst_equation > Applications > In medicine: modeling of growth of tumors Another application of logistic curve is in medicine, where the logistic differential equation is used to model the growth of tumors. This application can be considered an extension of the above-mentioned use in the framework of ecology (see also the Generalized logistic curve, allowing for more parameters). Denoting with X ( t ) {\displaystyle X(t)} the size of the tumor at time t {\displaystyle t} , its dynamics are governed by which is of the type where F ( X ) {\displaystyle F(X)} is the proliferation rate of the tumor.
Preorder Other Preorder > Examples > Other Further examples: Every finite topological space gives rise to a preorder on its points by defining x ≤ y {\displaystyle x\leq y} if and only if x belongs to every neighborhood of y. Every finite preorder can be formed as the specialization preorder of a topological space in this way. That is, there is a one-to-one correspondence between finite topologies and finite preorders. However, the relation between infinite topological spaces and their specialization preorders is not one-to-one.A net is a directed preorder, that is, each pair of elements has an upper bound. The definition of convergence via nets is important in topology, where preorders cannot be replaced by partially ordered sets without losing important features.The relation defined by x ≤ y {\displaystyle x\leq y} if f ( x ) ≤ f ( y ) , {\displaystyle f(x)\leq f(y),} where f is a function into some preorder.
Time-temperature superposition Time-temperature superposition Time–temperature_superposition > Time-temperature superposition Consider the relaxation modulus E at two temperatures T and T0 such that T > T0. At constant strain, the stress relaxes faster at the higher temperature. The principle of time-temperature superposition states that the change in temperature from T to T0 is equivalent to multiplying the time scale by a constant factor aT which is only a function of the two temperatures T and T0. In other words, E ( t , T ) = E ( t a T , T 0 ) .
Allostasis Nature of concept Allostasis > Nature of concept Homeostasis is formed from the Greek adjective homoios, meaning "similar," and the noun stasis, meaning "standing;" thus, "standing at about the same level." Wingfield states:The concept of allostasis, maintaining stability through change, is a fundamental process through which organisms actively adjust to both predictable and unpredictable events... Allostatic load refers to the cumulative cost to the body of allostasis, with allostatic overload... being a state in which serious pathophysiology can occur... Using the balance between energy input and expenditure as the basis for applying the concept of allostasis, two types of allostatic overload have been proposed.Sterling (2020) proposed several interrelated points that constitute the allostasis model:Animals are designed to be efficient. Efficiency requires a brain to predict what will be needed and avoid costly errors.
Scalp psoriasis Pathogenetic Plaque_psoriasis > Diagnosis > Classification > Pathogenetic Another classification scheme considers genetic and demographic factors. Type 1 has a positive family history, starts before the age of 40, and is associated with the human leukocyte antigen, HLA-Cw6. Conversely, type 2 does not show a family history, presents after age 40, and is not associated with HLA-Cw6. Type 1 accounts for about 75% of persons with psoriasis.The classification of psoriasis as an autoimmune disease has sparked considerable debate. Researchers have proposed differing descriptions of psoriasis and psoriatic arthritis; some authors have classified them as autoimmune diseases while others have classified them as distinct from autoimmune diseases and referred to them as immune-mediated inflammatory diseases.
Molecular chemistry Bonding Modern_chemistry > Modern principles > Bonding An ionic bond is formed when a metal loses one or more of its electrons, becoming a positively charged cation, and the electrons are then gained by the non-metal atom, becoming a negatively charged anion. The two oppositely charged ions attract one another, and the ionic bond is the electrostatic force of attraction between them. For example, sodium (Na), a metal, loses one electron to become an Na+ cation while chlorine (Cl), a non-metal, gains this electron to become Cl−.
Psychopharmacology Antidepressants Psychopharmacology > Psychopharmacological substances > Antidepressants They inhibit monoamine oxidase, the enzyme that metabolizes the monoamine neurotransmitters in the presynaptic terminals that are not contained in protective synaptic vesicles. The inhibition of the enzyme increases the amount of neurotransmitter available for release. It increases norepinephrine, dopamine, and 5-HT, thus increasing the action of the transmitters at their receptors.
Cache coherent system Coherence protocols Cache_coherent_system > Coherence protocols All processors snoop the request and respond appropriately. Write propagation in snoopy protocols can be implemented by either of the following methods: Write-invalidate When a write operation is observed to a location that a cache has a copy of, the cache controller invalidates its own copy of the snooped memory location, which forces a read from main memory of the new value on its next access. Write-update When a write operation is observed to a location that a cache has a copy of, the cache controller updates its own copy of the snooped memory location with the new data.If the protocol design states that whenever any copy of the shared data is changed, all the other copies must be "updated" to reflect the change, then it is a write-update protocol.
Connecting tubule Principal cells Collecting_duct_system > Structure > Cells > Principal cells Aldosterone also increases the number of Na⁺/K⁺-ATPase pumps: 949 that allow increased sodium reabsorption and potassium excretion. : 336 Vasopressin determines the expression of aquaporin channels that provide a physical pathway for water to pass through the principal cells. Together, aldosterone and vasopressin let the principal cell control the quantity of water that is reabsorbed.
Boundary layer thickness Moment method Boundary_layer_thickness > The bounded boundary layer description > Moment method This parameter was shown to track the boundary layer shape changes that accompany the laminar to turbulent boundary layer transition.Numerical errors encountered in calculating the moments, especially the higher-order moments, are a serious concern. Small experimental or numerical errors can cause the nominally free stream portion of the integrands to blow up. There are certain numerical calculation recommendations that can be followed to mitigate these errors.
Group 1 CD1-restricted T cells Mycobacterium tuberculosis infection Group_1_CD1-restricted_T_cells > Function > Mycobacterium tuberculosis infection Studies using CD1b tetramers presenting the mycobacterial product glucose monomycolate identified two CD4+ TCRαβ+ T cell populations which differ from the otherwise variable TCR composition of previously isolated subsets, one termed 'GEM (Germline-encoded, mycolyl-reactive)' for their conserved TCR repertoire (specifically TRAV1-2+TRAJ9+) and 'LDN5-like' (TRBV4-1+). These cells are rare in individuals that have not encountered Mycobacterium tuberculosis.CD1 expression is downregulated in antigen presenting cells infected with live Mycobacteria, perhaps as a means of immune evasion. This downregulation can be also found in some leukemia cells.
Resection margin Associated errors and recurrence rate Resection_margin > Associated errors and recurrence rate This determination is made with the full understanding of "false negative error" intrinsic in the bread loafing technique of histology (also known as POMA - a term used by the NCCN). The higher the false negative error is, the higher the recurrence rate of a cancer or tumor at the surgical margin. This is due to the misreading of a pathology specimen as being clear of residual tumor when there is actually residual tumor left where the specimen was not cut and mounted on the histology slide.
Complex adaptive system Characteristics Complex_adaptive_system > Overview > Characteristics There has to be a constant flow of energy to maintain the organization of the system Complex systems have a history. They evolve and their past is co-responsible for their present behaviour Elements in the system may be ignorant of the behaviour of the system as a whole, responding only to the information or physical stimuli available to them locallyRobert Axelrod & Michael D. Cohen identify a series of key terms from a modeling perspective: Strategy, a conditional action pattern that indicates what to do in which circumstances Artifact, a material resource that has definite location and can respond to the action of agents Agent, a collection of properties, strategies & capabilities for interacting with artifacts & other agents Population, a collection of agents, or, in some situations, collections of strategies System, a larger collection, including one or more populations of agents and possibly also artifacts Type, all the agents (or strategies) in a population that have some characteristic in common Variety, the diversity of types within a population or system Interaction pattern, the recurring regularities of contact among types within a system Space (physical), location in geographical space & time of agents and artifacts Space (conceptual), "location" in a set of categories structured so that "nearby" agents will tend to interact Selection, processes that lead to an increase or decrease in the frequency of various types of agent or strategies Success criteria or performance measures, a "score" used by an agent or designer in attributing credit in the selection of relatively successful (or unsuccessful) strategies or agentsTurner and Baker synthesized the characteristics of complex adaptive systems from the literature and tested these characteristics in the context of creativity and innovation. Each of these eight characteristics had been shown to be present in the creativity and innovative processes: Path dependent: Systems tend to be sensitive to their initial conditions.
Nassi–Shneiderman diagram Diagrams Program_structure_diagram > Diagrams The only difference between the two is the order in which the steps involved are completed. In the test first situation, when the program encounters the block it tests to see if the condition is fulfilled, then, if it is not completes the process blocks and then loops back. The test is performed again and, if the condition is still unfulfilled, it processes again.
Insulin-degrading enzyme Mechanism Insulin-degrading_enzyme > Mechanism As a consequence of transfer of the proton of Glu111 onto the amide nitrogen of substrate that occurred in TS3, the peptide N—C bond is broken. A look at the whole reaction path indicates that the rate-determining step in this process is the nucleophilic addition. After this point, the catalytic event should proceed without particular obstacles.
Metabolic trapping Summary Metabolic_trapping This trapping occurred because once the glucose was pulled into the cells, the glucose was phosphorylated to cause the concentration of glucose in the cell to appear lower than it is, which then promotes the transport of more glucose. This phosphorylation of the radioactive glucose caused the metabolic trapping in the heart and the brain. The lungs, liver, and kidneys did not experience metabolic trapping, and the radioactive glucose that was not trapped was excreted in the urine.
Properties of metals, metalloids and nonmetals Metalloids Properties_of_metals,_metalloids_and_nonmetals > Anomalous properties > Metalloids Both are about a thousand times more acidic than pure sulfuric acid. In 2004, a boron compound broke this record by a thousand fold with the synthesis of carborane acid H(CHB11Cl11). Another metalloid, antimony, features in the strongest known acid, a mixture 10 billion times stronger than carborane acid.
Noise factor Optical noise figure Noise_figure > Optical noise figure We may replace the photodiode by a thermal power meter, and measured photocurrent I by measured temperature change Δ θ {\displaystyle \mathrm {\Delta \theta } } . "Power", being proportional to I2 or P2, is also proportional to ( Δ θ ) {\displaystyle (\mathrm {\Delta \theta } )} 2. Thermal power meters can be built at all frequencies.
Function object Summary Function_object In computer programming, a function object is a construct allowing an object to be invoked or called as if it were an ordinary function, usually with the same syntax (a function parameter that can also be a function). In some languages, particularly C++, function objects are often called functors (not related to the functional programming concept).
Measure theoretic Definition Measurable_set > Definition Most measures met in practice in analysis (and in many cases also in probability theory) are Radon measures. Radon measures have an alternative definition in terms of linear functionals on the locally convex topological vector space of continuous functions with compact support. This approach is taken by Bourbaki (2004) and a number of other sources. For more details, see the article on Radon measures.
Level ancestor problem Stage 3: combining the two approaches Level_ancestor_problem > Ladder algorithm > Stage 3: combining the two approaches A single jump pointer takes any query at least halfway up the tree after which climbing up only one ladder will answer the query. This results in O(n log n) pre-processing time and O(1) query time. The pre-processing can be further reduced to O(n) time by an application of the Method of Four Russians, in which the tree is reduced to a smaller tree with linear preprocessing, and a collection of very small trees, which are small enough that an exhaustive enumeration of all trees and the preprocessing of those trees is still O(n) time. Trees of size (log n)/4 suffice.
Four-force In general relativity Four-force > In general relativity In special relativity the transformation will be a Lorentz transformation between coordinate systems moving with a relative constant velocity whereas in general relativity it will be a general coordinate transformation. Consider the four-force F μ = ( F 0 , F ) {\displaystyle F^{\mu }=(F^{0},\mathbf {F} )} acting on a particle of mass m {\displaystyle m} which is momentarily at rest in a coordinate system. The relativistic force f μ {\displaystyle f^{\mu }} in another coordinate system moving with constant velocity v {\displaystyle v} , relative to the other one, is obtained using a Lorentz transformation: where β = v / c {\displaystyle {\boldsymbol {\beta }}=\mathbf {v} /c} .
Salted bomb Design Salted_bomb > Design Salted versions of both fission and fusion weapons can be made by surrounding the core of the explosive device with a material containing an element that can be converted to a highly radioactive isotope by neutron bombardment. When the bomb explodes, the element absorbs neutrons released by the nuclear reaction, converting it to its radioactive form. The explosion scatters the resulting radioactive material over a wide area, leaving it uninhabitable far longer than an area affected by typical nuclear weapons. In a salted hydrogen bomb, the radiation case around the fusion fuel, which normally is made of some fissionable element, is replaced with a metallic salting element.
Antioxidative stress Role in disease Antioxidative_stress > Health effects > Role in disease Antioxidants attenuate the Th-1 immune response, responsible for eliminating bacterial and fungal threats, while the Th-2 immune response compensates for a weak Th-1 response by increasing its own responders, which may be not only ineffective, but overall destructive to healthy surrounding tissues, thus harmful. The net result: over-supplementation of antioxidants are a direct, underlying cause of allergenic diseases and skin alterations, spurring signs (objective indications) and symptoms (subjective states) of localized and disseminated medical conditions. Because of the low-level biochemical nature of these immunological systems and their processes, the consequences of antioxidative stress can result in overlying symptoms, leading or contributing to chronic, co-morbid, localized, and/or disseminated disease states, that are clinically challenging to successfully treat. A diet rich in anti-oxidants could allow for skin alterations such as acute acne or chronic non-infectious lesions, especially when the Th-1 immune process is persistently compromised by an overload of dietary antioxidant sources, like daily ingesting of vitamin C supplements, for example. Allergenic reactions by invading atopic pathogens, well beyond the scope of microbiota, can become initial factors triggering chronic atopic disease. When relating to atopic skin conditions caused by chronic antioxidative stress, symptoms similar to Chronic granulomatous disease (CGD) may appear, a disease where phagocytes have an impaired ability to destroy pathogens due to a genetic inability to effectively kill pathogens by ROS, versus supplementation induced inability caused by antioxidative stress.
Rust programming language Performance Rust_programming_language > Performance It has been empirically demonstrated that unsafe Rust does not always perform faster than safe Rust, and can even be slower in some cases.Many of Rust's features are so-called zero-cost abstractions, meaning they are optimized away at compile time and incur no runtime penalty. The ownership and borrowing system permits zero-copy implementations for some performance-sensitive tasks, such as parsing. Static dispatch is used by default to eliminate method calls, with the exception of methods called on dynamic trait objects. The compiler also uses inline expansion to eliminate function calls and statically-dispatched method invocations.Since Rust utilizes LLVM, any performance improvements in LLVM also carry over to Rust. Unlike C and C++, Rust allows for reordering struct and enum elements to reduce the sizes of structures in memory, for better memory alignment, and to improve cache access efficiency.
Structural Analysis Loads Structural_Analysis > Structures and loads > Loads Once the dimensional requirement for a structure have been defined, it becomes necessary to determine the loads the structure must support. Structural design, therefore begins with specifying loads that act on the structure. The design loading for a structure is often specified in building codes. There are two types of codes: general building codes and design codes, engineers must satisfy all of the code's requirements in order for the structure to remain reliable.
Periodic Table Future extension beyond the seventh period Periodic_tables > Future extension beyond the seventh period As such, it may be that the periodic table practically ends around element 120, as elements become too short-lived to observe; the era of discovering new elements would thus be close to its end.Alternatively, quark matter may become stable at high mass numbers, in which the nucleus is composed of freely flowing up and down quarks instead of binding them into protons and neutrons; this would create a continent of stability instead of an island. Other effects may come into play: for example, in very heavy elements the 1s electrons are likely to spend a significant amount of time so close to the nucleus that they are actually inside it, which would make them vulnerable to electron capture.Even if eighth-row elements can exist, producing them is likely to be difficult, and it should become even more difficult as atomic number rises. Although the 8s elements are expected to be reachable with present means, the first few 5g elements are expected to require new technology, if they can be produced at all. Experimentally characterising these elements chemically would also pose a great challenge.
Loop Guru Summary Loop_Guru Loop Guru's main exuberant oeuvre of lively rhythms and effusive sounds is occasionally punctuated by more contemplative albums (e.g., The Third Chamber) that are reminiscent and influenced by ambient music and similar to musical artists such as Brian Eno and Jon Hassell. Past and present guest musicians and collaborators include Natacha Atlas, Sussan Deyhim, Mad Jym, Count Dubulah (also known as Nick Page, Psycho Karaoke and Dub Colossus) and Cat von Trapp.Their single "Paradigm Shuffle", one of their more popular releases, was built around "I Have a Dream", Martin Luther King Jr. 's 1963 speech.Muddyman died on 27 March 2022.
Higher-order abstract syntax Relation to first-order abstract syntax Higher-order_abstract_syntax > Relation to first-order abstract syntax An abstract syntax is abstract because it is represented by mathematical objects that have certain structure by their very nature. For instance, in first-order abstract syntax (FOAS) trees, as commonly used in compilers, the tree structure implies the subexpression relation, meaning that no parentheses are required to disambiguate programs (as they are, in the concrete syntax). HOAS exposes additional structure: the relationship between variables and their binding sites.
Natural immunity Artificially acquired passive immunity Natural_immunity > Passive immunity > Artificially acquired passive immunity Artificially acquired passive immunity is a short-term immunization induced by the transfer of antibodies, which can be administered in several forms; as human or animal blood plasma, as pooled human immunoglobulin for intravenous (IVIG) or intramuscular (IG) use, and in the form of monoclonal antibodies (MAb). Passive transfer is used prophylactically in the case of immunodeficiency diseases, such as hypogammaglobulinemia. It is also used in the treatment of several types of acute infection, and to treat poisoning. Immunity derived from passive immunization lasts for only a short period of time, and there is also a potential risk for hypersensitivity reactions, and serum sickness, especially from gamma globulin of non-human origin.The artificial induction of passive immunity has been used for over a century to treat infectious disease, and before the advent of antibiotics, was often the only specific treatment for certain infections. Immunoglobulin therapy continued to be a first line therapy in the treatment of severe respiratory diseases until the 1930s, even after sulfonamide lot antibiotics were introduced.
Automatic variable Summary Automatic_variable In computer programming, an automatic variable is a local variable which is allocated and deallocated automatically when program flow enters and leaves the variable's scope. The scope is the lexical context, particularly the function or block in which a variable is defined. Local data is typically (in most languages) invisible outside the function or lexical context where it is defined. Local data is also invisible and inaccessible to a called function, but is not deallocated, coming back in scope as the execution thread returns to the caller.
Actian Zen (PSQL) Relational Database Engine Actian_Zen_(PSQL) > DBMS architecture > Relational Database Engine The second database engine, the SQL Relational Database Engine or SRDE, operates in a manner similar to other relational database engines, that is, through the support of Structured Query Language queries. SRDE parses SQL queries and sends them to the MKDE to run. The SRDE implements SQL-92. Significant other features include relational integrity, database security, and temporary tables. SRDE extends its functionality by supporting stored procedures, user-defined functions, and triggers.In addition to its support for SQL-92, the SRDE supports several significant features of COBOL: COBOL data types and COBOL OCCURS and VARIANT records.
MO theory Overview MO_theory > Overview Assignments can be made to these signals indicated by the transition of electrons moving from one orbital at a lower energy to a higher energy orbital. The molecular orbital diagram for the final state describes the electronic nature of the molecule in an excited state. Although in MO theory some molecular orbitals may hold electrons that are more localized between specific pairs of molecular atoms, other orbitals may hold electrons that are spread more uniformly over the molecule.
Log management software Summary Log_management_software Log management (LM) comprises an approach to dealing with large volumes of computer-generated log messages (also known as audit records, audit trails, event-logs, etc.). Log management generally covers: Log collection Centralized log aggregation Long-term log storage and retention Log rotation Log analysis (in real-time and in bulk after storage) Log search and reporting.
Data model diagram Data architecture Data_models > Topics > Data architecture Data architecture is the design of data for use in defining the target state and the subsequent planning needed to hit the target state. It is usually one of several architecture domains that form the pillars of an enterprise architecture or solution architecture. A data architecture describes the data structures used by a business and/or its applications. There are descriptions of data in storage and data in motion; descriptions of data stores, data groups, and data items; and mappings of those data artifacts to data qualities, applications, locations, etc. Essential to realizing the target state, Data architecture describes how data is processed, stored, and utilized in a given system. It provides criteria for data processing operations that make it possible to design data flows and also control the flow of data in the system.
Epidemiology of tuberculosis History Giant_multinucleated_cell > History (Villemin's findings were confirmed in 1867 and 1868 by John Burdon-Sanderson.) Robert Koch identified and described the bacillus causing tuberculosis, M. tuberculosis, on 24 March 1882. In 1905, he was awarded the Nobel Prize in Physiology or Medicine for this discovery.
Perfect hash function Pseudocode Perfect_hash_function > Construction > Pseudocode algorithm hash, displace, and compress is (1) Split S into buckets Bi := g−1({i})∩S,0 ≤ i < r (2) Sort buckets Bi in falling order according to size \|Bi\| (3) Initialize array T with 0's (4) for all i ∈, in the order from (2), do (5) for l ← 1,2,... (6) repeat forming Ki ← {Φl(x)\|x ∈ Bi} (6) until \|Ki\|=\|Bi\| and Ki∩{j\|T=1}= ∅ (7) let σ(i):= the successful l (8) for all j ∈ Ki let T:= 1 (9) Transform (σi)0≤i
Anaerobic exercise Metabolism Anaerobic_exercise > Metabolism Fatigue, which is muscle failure, is a complex subject that depends on more than just changes to lactate concentration. Energy availability, oxygen delivery, perception to pain, and other psychological factors all contribute to muscular fatigue. Elevated muscle and blood lactate concentrations are a natural consequence of any physical exertion. The effectiveness of anaerobic activity can be improved through training.Anaerobic exercise also increases an individual's basal metabolic rate (BMR).
Database index Support for fast lookup Clustered_index > Usage > Support for fast lookup Most database software includes indexing technology that enables sub-linear time lookup to improve performance, as linear search is inefficient for large databases. Suppose a database contains N data items and one must be retrieved based on the value of one of the fields. A simple implementation retrieves and examines each item according to the test.
RNA timestamp Background RNA_timestamp > Background RNA-seq requires the destruction of the cell, thus only revealing the transcriptome at a single moment. Understanding expression times and patterns of genes transcription would create a deeper understanding of the roles of genes and how regulation of expression timing could be affecting cellular processes and possible dysregulation could be contributing to disease development. In recent years, there have been other technologies created with the end goal of determining the age of RNA transcripts within a given cell.
Signal spectrum Related concepts Power_spectral_density > Related concepts A "spectrum" generally means the power spectral density, as discussed above, which depicts the distribution of signal content over frequency. For transfer functions (e.g., Bode plot, chirp) the complete frequency response may be graphed in two parts: power versus frequency and phase versus frequency—the phase spectral density, phase spectrum, or spectral phase. Less commonly, the two parts may be the real and imaginary parts of the transfer function.
Finite-element analysis Application Finite-element_analysis > Application Similarly, the desired level of accuracy required and associated computational time requirements can be managed simultaneously to address most engineering applications. FEM allows entire designs to be constructed, refined, and optimized before the design is manufactured. The mesh is an integral part of the model and must be controlled carefully to give the best results.
Total Dissolved Solids Summary Total_Dissolved_Solids The principal application of TDS is in the study of water quality for streams, rivers, and lakes. Although TDS is not generally considered a primary pollutant (e.g. it is not deemed to be associated with health effects), it is used as an indication of aesthetic characteristics of drinking water and as an aggregate indicator of the presence of a broad array of chemical contaminants. Primary sources for TDS in receiving waters are agricultural runoff and residential (urban) runoff, clay-rich mountain waters, leaching of soil contamination, and point source water pollution discharge from industrial or sewage treatment plants.
Glossary of cell biology I Glossary_of_cell_biology > I DNA replication does not occur during interkinesis, unlike during the normal interphase that precedes meiosis I and mitosis. interphase All stages of the cell cycle excluding cell division.
Malignant cancer Screening Cancer_medication > Screening Unlike diagnostic efforts prompted by symptoms and medical signs, cancer screening involves efforts to detect cancer after it has formed, but before any noticeable symptoms appear. This may involve physical examination, blood or urine tests or medical imaging.Cancer screening is not available for many types of cancers. Even when tests are available, they may not be recommended for everyone. Universal screening or mass screening involves screening everyone.
UV-Vis spectroscopy Ultraviolet–visible spectrophotometer UV_spectroscopy > Ultraviolet–visible spectrophotometer A complete spectrum of the absorption at all wavelengths of interest can often be produced directly by a more sophisticated spectrophotometer. In simpler instruments the absorption is determined one wavelength at a time and then compiled into a spectrum by the operator. By removing the concentration dependence, the extinction coefficient (ε) can be determined as a function of wavelength.
Signal strength meter Accuracy S_meter > Accuracy Most S meters on traditional analog receivers are not calibrated and in practice can only provide a relative measure of signal strength based on the receiver's AGC voltage. Some S meters on traditional analog receivers are calibrated to read S9 for an input of -73 dBm but do not provide the correct 6 dB per S unit correspondence. Often the correlation between a radio listener's qualitative impression of signal strength and the actual strength of the received signal on an analog receiver is poor, because the receiver's AGC holds the audio output fairly constant despite changes in input signal strength.
Matrix (blinkenlights) Summary Matrix_(blinkenlights) Both installations feature higher resolutions and eight shades of grey. On August 2023 a new Installation was shown on the CCCamp in Mildenberg.
Insulin signal transduction pathway Action on the cell Insulin_signal_transduction_pathway > Transduction pathway > Action on the cell It also leads to cell survival and cell proliferation. Most importantly, the PI-3K pathway is responsible for the distribution of glucose for important cell functions. For example, the suppression of hepatic glucose synthesis and the activation of glycogen synthesis.
Sexagenary cycle Sexagenary months Sexagesimal_cycle > Sexagenary months The branches are used marginally to indicate months. Despite there being twelve branches and twelve months in a year, the earliest use of branches to indicate a twelve-fold division of a year was in the 2nd century BC. They were coordinated with the orientations of the Great Dipper, (建子月: jiànzǐyuè, 建丑月: jiànchǒuyuè, etc.).
Thermal flywheel effect Use of thermal mass in different climates Thermal_mass > Thermal mass in buildings > Use of thermal mass in different climates The correct use and application of thermal mass is dependent on the prevailing climate in a district.
Sum over histories The propagator Functional_integral_(QFT) > Quantum field theory > The propagator There, the path integral in the usual variables, with fixed boundary conditions, gives the probability amplitude for a particle to go from point x to point y in time T: K ( x , y ; T ) = ⟨ y ; T ∣ x ; 0 ⟩ = ∫ x ( 0 ) = x x ( T ) = y e i S D x . {\displaystyle K(x,y;T)=\langle y;T\mid x;0\rangle =\int _{x(0)=x}^{x(T)=y}e^{iS}\,Dx.} This is called the propagator.
Alpha cells Non-neuronal Control Alpha_cell > Regulation of glucagon secretion > Non-neuronal Control Non-neuronal control has been found to be indirect paracrine regulation through ions, hormones, and neurotransmitters. Zinc, insulin, serotonin, γ-aminobutyric acid, and γ-hydroxybutyrate, all of which are released by beta cells in the pancreas, have been found to suppress glucagon production in alpha cells. Delta cells also release somatostatin which has been found to inhibit glucagon secretion.Zinc is secreted at the same time as insulin by the beta cells in the pancreas. It has been proposed to act as a paracrine signal to inhibit glucagon secretion in alpha cells.
Computational Chemistry Summary Computational_Chemistry In all cases, the computer time and other resources (such as memory and disk space) increase quickly with the size of the system being studied. That system can be a molecule, a group of molecules, or a solid.
Forensic geology Ph Forensic_geology > Chemical description > Ph In recent years that has been much improvement to portable pH meters that are used in the field. Decades ago the portable devices has numerous malfunctions regarding the electrodes. Nowadays pH meters due to microcircuitry and plastic not only reduces the cost of these devices but also allows for an overall better protection of the unit. Further studies are attempting a technique to produce a device to obtain microsite pH in various soil systems by using plant cells via microprocedures. This would also be able to decipher the different pH present in the soil matrix.
Glossary of engineering: A–L C Glossary_of_engineering:_A–L > C In its scalar form, the law is: F = k e q 1 q 2 r 2 {\displaystyle F=k_{e}{\frac {q_{1}q_{2}}{r^{2}}}} , where ke is the Coulomb constant (ke ≈ 9×109 N⋅m2⋅C−2), q1 and q2 are the signed magnitudes of the charges, and the scalar r is the distance between the charges. The force of the interaction between the charges is attractive if the charges have opposite signs (i.e., F is negative) and repulsive if like-signed (i.e., F is positive). Being an inverse-square law, the law is analogous to Isaac Newton's inverse-square law of universal gravitation.
Event correlation Action triggering Event_correlation > Event correlation in integrated management > Step-by-step decomposition > Action triggering At this stage, the event correlator is left with at most a handful of events that need to be acted upon. Strictly speaking, event correlation ends here. However, by language abuse, the event correlators found on the market (e.g., in network management) sometimes also include problem-solving capabilities. For instance, they may trigger corrective actions or further investigations automatically.
Uranium-236 Creation and yield Uranium-236 > Creation and yield The second-most used fissile isotope plutonium-239 can also fission or not fission on absorbing a thermal neutron. The product plutonium-240 makes up a large proportion of reactor-grade plutonium (plutonium recycled from spent fuel that was originally made with enriched natural uranium and then used once in an LWR). 240Pu decays with a half-life of 6561 years into 236U.
Genera (operating system) Features Genera_(operating_system) > Features Genera also has support for various network protocols and applications using those. It has extensive support for TCP/IP. Genera supports one-processor machines with several threads (called processes). Genera supports several different types of garbage collection (GC): full GC, in-place GC, incremental GC, and ephemeral GC.
Chronic viral hepatitis Diagnosis Chronic_viral_hepatitis > Diagnosis The degree of elevation (i.e. levels in the hundreds vs. in the thousands), the predominance for AST vs. ALT elevation, and the ratio between AST and ALT are informative of the diagnosis.Ultrasound, CT, and MRI can all identify steatosis (fatty changes) of the liver tissue and nodularity of the liver surface suggestive of cirrhosis. CT and especially MRI are able to provide a higher level of detail, allowing visualization and characterize such structures as vessels and tumors within the liver. Unlike steatosis and cirrhosis, no imaging test is able to detect liver inflammation (i.e. hepatitis) or fibrosis. Liver biopsy is the only definitive diagnostic test that is able to assess inflammation and fibrosis of the liver.
Polynomial-time approximation scheme As a complexity class Efficient_polynomial-time_approximation_scheme > As a complexity class The term PTAS may also be used to refer to the class of optimization problems that have a PTAS. PTAS is a subset of APX, and unless P = NP, it is a strict subset. Membership in PTAS can be shown using a PTAS reduction, L-reduction, or P-reduction, all of which preserve PTAS membership, and these may also be used to demonstrate PTAS-completeness. On the other hand, showing non-membership in PTAS (namely, the nonexistence of a PTAS), may be done by showing that the problem is APX-hard, after which the existence of a PTAS would show P = NP. APX-hardness is commonly shown via PTAS reduction or AP-reduction.
Pinocchio paradox The paradox Pinocchio_paradox > The paradox In his next article, "Pinocchio against the dialetheists", Eldridge-Smith states: "If it is a true contradiction that Pinocchio's nose grows and does not grow, then such a world is metaphysically impossible, not merely semantically impossible." He then reminds the readers that, when (in Buridan's bridge) Socrates asked if he may cross a bridge, Plato responded that he may cross the bridge only "if in the first proposition that you would utter you speak the truth. But surely, if you speak falsely I shall throw you into the water."
Stack machines Commercial stack machines Stack_machines > History and implementations > Commercial stack machines The accumulator register buffered the memory stack's top data value. Variants of load and store opcodes controlled when that register was spilled to the memory stack or reloaded from there. HP 3000 (Classic, not PA-RISC) Tandem Computers T/16.
Memory dependency speculation Memory disambiguation mechanisms Memory_disambiguation > Memory disambiguation mechanisms Modern microprocessors use the following mechanisms, implemented in hardware, to resolve ambiguous dependences and recover when a dependence was violated.
Casimir vacuum Papers, books and lectures Dynamical_Casimir_Effect > Further reading > Papers, books and lectures S2CID 25323874. Bordag, M.; Mohideen, U.; Mostepanenko, V. M. (October 2001).
Stochastic complexity History and context Algorithmic_complexity_theory > History and context The general consensus in the scientific community, however, was to associate this type of complexity with Kolmogorov, who was concerned with randomness of a sequence, while Algorithmic Probability became associated with Solomonoff, who focused on prediction using his invention of the universal prior probability distribution. The broader area encompassing descriptional complexity and probability is often called Kolmogorov complexity. The computer scientist Ming Li considers this an example of the Matthew effect: "...to everyone who has, more will be given..."There are several other variants of Kolmogorov complexity or algorithmic information. The most widely used one is based on self-delimiting programs, and is mainly due to Leonid Levin (1974). An axiomatic approach to Kolmogorov complexity based on Blum axioms (Blum 1967) was introduced by Mark Burgin in the paper presented for publication by Andrey Kolmogorov.
Constructive quantum field theory Summary Constructive_quantum_field_theory Along with work of their students, coworkers, and others, constructive field theory resulted in a mathematical foundation and exact interpretation to what previously was only a set of recipes, also in the case d < 4. Theoretical physicists had given these rules the name "renormalization," but most physicists had been skeptical about whether they could be turned into a mathematical theory. Today one of the most important open problems, both in theoretical physics and in mathematics, is to establish similar results for gauge theory in the realistic case d = 4.
Dynamic speckle Information content Dynamic_speckle > Information content The dynamic pattern shows then the changes that, if they are analyzed along time, represent the activity of the illuminated material. The visual effect is that of a boiling liquid or the image in a TV set far from tuning. It can be analyzed by means of several mathematical and statistical tools and provide numeric or visual information on its magnitude, the not well defined idea of activity. Because the number of scattering centers is very high the collective phenomenon is hard to interpret and their individual contributions to the final result can not be inferred.
Meshless method Recent development Meshfree_method > Recent development Moreover, W2 formulations allow the use of polynomial and radial basis functions in the creation of shape functions (it accommodates the discontinuous displacement functions, as long as it is in G1 space), which opens further rooms for future developments. The W2 formulation has also led to the development of combination of meshfree techniques with the well-developed FEM techniques, and one can now use triangular mesh with excellent accuracy and desired softness. A typical such a formulation is the so-called smoothed finite element method (or S-FEM).
Dual diagnosis Summary Dual_diagnosis Dual diagnosis (also called co-occurring disorders (COD) or dual pathology) is the condition of having a mental illness and a comorbid substance use disorder. There is considerable debate surrounding the appropriateness of using a single category for a heterogeneous group of individuals with complex needs and a varied range of problems. The concept can be used broadly, for example depression and alcohol use disorder, or it can be restricted to specify severe mental illness (e.g. psychosis, schizophrenia) and substance use disorder (e.g. cannabis use), or a person who has a milder mental illness and a drug dependency, such as panic disorder or generalized anxiety disorder and is dependent on opioids. Diagnosing a primary psychiatric illness in people who use substances is challenging as substance use disorder itself often induces psychiatric symptoms, thus making it necessary to differentiate between substance induced and pre-existing mental illness.Those with co-occurring disorders face complex challenges. They have increased rates of relapse, hospitalization, homelessness, and HIV and hepatitis C infection compared to those with either mental or substance use disorders alone.
Hypercycle (chemistry) Evolutionary dynamics: a mathematical model Hypercycle_(chemistry) > Evolution > Evolutionary dynamics: a mathematical model According to the definition of a hypercycle, it is a nonlinear, dynamic system, and, in the simplest case, it can be assumed that it grows at a rate determined by a system of quadratic differential equations. Then, the competition between evolving hypercycles can be modelled using the differential equation: C l ˙ = q l C l 2 − C l ϕ C {\displaystyle {\dot {C_{l}}}=q_{l}C_{l}^{2}-C_{l}{\frac {\phi }{C}}} where C = ∑ l C l . {\displaystyle C=\sum _{l}C_{l}.}
Central Limit Theorem Lyapunov CLT Central_Limit_Theorem > Independent sequences > Lyapunov CLT The theorem is named after Russian mathematician Aleksandr Lyapunov. In this variant of the central limit theorem the random variables X i {\textstyle X_{i}} have to be independent, but not necessarily identically distributed. The theorem also requires that random variables \| X i \| {\textstyle \left\|X_{i}\right\|} have moments of some order ( 2 + δ ) {\textstyle (2+\delta )} , and that the rate of growth of these moments is limited by the Lyapunov condition given below.
Anaerobic respiration Ecological importance Anaerobic_respiration > Ecological importance Another example is methanogenesis, a form of carbon-dioxide respiration, that is used to produce methane gas by anaerobic digestion. Biogenic methane is used as a sustainable alternative to fossil fuels. On the negative side, uncontrolled methanogenesis in landfill sites releases large volumes of methane into the atmosphere, where it acts as a powerful greenhouse gas. Sulfate respiration produces hydrogen sulfide, which is responsible for the characteristic 'rotten egg' smell of coastal wetlands and has the capacity to precipitate heavy metal ions from solution, leading to the deposition of sulfidic metal ores.

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