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Permutation (music) Summary Permutation_(music) In that regard, a musical permutation is a combinatorial permutation from mathematics as it applies to music. Permutations are in no way limited to the twelve-tone serial and atonal musics, but are just as well utilized in tonal melodies especially during the 20th and 21st centuries, notably in Rachmaninoff's Variations on the Theme of Paganini for orchestra and piano.Cyclical permutation (also called rotation) is the maintenance of the original order of the tone row with the only change being the initial pitch class, with the original order following after. A secondary set may be considered a cyclical permutation beginning on the sixth member of a hexachordally combinatorial row. The tone row from Berg's Lyric Suite, for example, is realized thematically and then cyclically permuted (0 is bolded for reference): 5 4 0 9 7 2 8 1 3 6 t e 3 6 t e 5 4 0 9 7 2 8 1
Sign language Iconicity Sign_language > Linguistics > Iconicity It is defined as a fully grammatical and central aspect of a sign language rather than a peripheral phenomenon.The cognitive linguistics perspective allows for some signs to be fully iconic or partially iconic given the number of correspondences between the possible parameters of form and meaning. In this way, the Israeli Sign Language (ISL) sign for ask has parts of its form that are iconic ("movement away from the mouth" means "something coming from the mouth"), and parts that are arbitrary (the handshape, and the orientation).Many signs have metaphoric mappings as well as iconic or metonymic ones. For these signs there are three-way correspondences between a form, a concrete source and an abstract target meaning.
Cognitive Model Embodied cognition Cognitive_Model > Dynamical systems > Modern dynamical systems > Open dynamical systems > Embodied cognition In this example, the Scrabble tiles allow the agent to offload working memory demands on to the tiles themselves. Instances where a functionally equivalent external artifact replaces functions that are normally performed internally by the agent, which is a special case of offloading.
Genetic imbalance Summary Genetic_imbalance Genetic imbalance is to describe situation when the genome of a cell or organism has more copies of some genes than other genes due to chromosomal rearrangements or aneuploidy. Changes in gene dosage, the number of times a given gene is present in the cell nucleus, can create a genetic imbalance.
In-place algorithm Examples In-place_algorithm > Examples Consequently, quicksort needs O(log2 n) additional space. Although this non-constant space technically takes quicksort out of the in-place category, quicksort and other algorithms needing only O(log n) additional pointers are usually considered in-place algorithms. Most selection algorithms are also in-place, although some considerably rearrange the input array in the process of finding the final, constant-sized result. Some text manipulation algorithms such as trim and reverse may be done in-place.
Bernoulli operator Definition Bernoulli_operator > Definition The left-adjoint of the Frobenius–Perron operator is the Koopman operator or composition operator. The general setting is provided by the Borel functional calculus. As a general rule, the transfer operator can usually be interpreted as a (left-)shift operator acting on a shift space.
M equilibrium Definition M_equilibrium > Definition M equilibrium is based on the following two conditions; Ordinal monotonicity: choice probabilities are ranked the same as the expected payoffs based on players’ beliefs. This replaces the assumption of “perfect maximization”. Ordinal consistency: player’s beliefs yield the same ranking of expected payoffs as their choices. This replaces the rational expectations or perfect-beliefs assumption.Let σ c {\displaystyle \sigma ^{c}} and σ b {\displaystyle \sigma ^{b}} denote the concatenations of players’ choice and belief profiles respectively, and let r a n k {\displaystyle rank} and π {\displaystyle \pi } denote the concatenations of players’ rank correspondences and profit functions.
Web Assembly Compilers WebAssembly_System_Interface > Compilers As of version 8, a standalone Clang can compile C and C++ to Wasm. Its initial aim was to support compilation from C and C++, though support for other source languages such as Rust, .NET languages and AssemblyScript (TypeScript-like) is also emerging. After the MVP release, there are plans to support multithreading and garbage collection which would make WebAssembly a compilation target for garbage-collected programming languages like C# (supported via Blazor), F# (supported via Bolero with help of Blazor), Python, and even JavaScript where the browser's just-in-time compilation speed is considered too slow.
Implicature Opting out of the cooperative principle Implicature > Conversational implicature > Opting out of the cooperative principle The cooperative principle and the maxims of conversation are not mandatory. A communicator can choose not to be cooperative; she can opt out of the cooperative principle by giving appropriate clues such as saying "My lips are sealed", or for example during a cross-examination at court. In such situations, no conversational implicatures arise.
Collective operation Gather Collective_operation > Gather We see that the asymptotic runtime is similar to the asymptotic runtime of reduce O ( α log ⁡ p + β n ) {\displaystyle {\mathcal {O}}(\alpha \log p+\beta n)} , but with the addition of a factor p to the term β n {\displaystyle \beta n} . This additional factor is due to the message size increasing in each step as messages get concatenated. Compare this to reduce where message size is a constant for operators like m i n {\displaystyle min} .
Bouncing ball dynamics Spin and angle of impact Bouncing_ball > Impact > Spin and angle of impact Upon impacting the ground, some translational kinetic energy can be converted to rotational kinetic energy and vice versa depending on the ball's impact angle and angular velocity. If the ball moves horizontally at impact, friction will have a 'translational' component in the direction opposite to the ball's motion. In the figure, the ball is moving to the right, and thus it will have a translational component of friction pushing the ball to the left. Additionally, if the ball is spinning at impact, friction will have a 'rotational' component in the direction opposite to the ball's rotation.
Cycles per instruction Explanation Cycles_per_instruction > Explanation With pipelining, a new instruction is fetched every clock cycle by exploiting instruction-level parallelism, therefore, since one could theoretically have five instructions in the five pipeline stages at once (one instruction per stage), a different instruction would complete stage 5 in every clock cycle and on average the number of clock cycles it takes to execute an instruction is 1 (CPI = 1). In this case, the processor is said to be scalar. With a single-execution-unit processor, the best CPI attainable is 1.
Power conditioning Uses Active_power_conditioner > Uses Power conditioners vary in function and size, generally according to their use. Some power conditioners provide minimal voltage regulation while others protect against six or more power quality problems. Units may be small enough to mount on a printed circuit board or large enough to protect an entire factory.
Mathematical product Commutative rings Product_(mathematics) > Commutative rings Commutative rings have a product operation.
Cloud computing issues Privacy Cloud_computing_issues > Privacy Privacy advocates have criticized the cloud model for giving hosting companies' greater ease to control—and thus, to monitor at will—communication between host company and end user, and access user data (with or without permission). Instances such as the secret NSA program, working with AT&T, and Verizon, which recorded over 10 million telephone calls between American citizens, causes uncertainty among privacy advocates, and the greater powers it gives to telecommunication companies to monitor user activity. A cloud service provider (CSP) can complicate data privacy because of the extent of virtualization (virtual machines) and cloud storage used to implement cloud service.
Boltzmann entropy History Boltzmann_entropy_formula > History W can be counted using the formula for permutations where i ranges over all possible molecular conditions and "!" denotes factorial. The "correction" in the denominator is due to the fact that identical particles in the same condition are indistinguishable. W is sometimes called the "thermodynamic probability" since it is an integer greater than one, while mathematical probabilities are always numbers between zero and one.
Infra-red (IR) spectroscopy Isotope effects IR_spectrum > Isotope effects Thus ν ~ ( 16 O ) ν ~ ( 18 O ) = 9 8 ≈ 832 788 . {\displaystyle {\frac {{\tilde {\nu }}(^{16}\mathrm {O} )}{{\tilde {\nu }}(^{18}\mathrm {O} )}}={\sqrt {\frac {9}{8}}}\approx {\frac {832}{788}}.} The effect of isotopes, both on the vibration and the decay dynamics, has been found to be stronger than previously thought.
Object modeling Summary Object_Model In computing, object model has two related but distinct meanings: The properties of objects in general in a specific computer programming language, technology, notation or methodology that uses them. Examples are the object models of Java, the Component Object Model (COM), or Object-Modeling Technique (OMT). Such object models are usually defined using concepts such as class, generic function, message, inheritance, polymorphism, and encapsulation.
Acid number Summary Acid_number In chemistry, acid value (AV, acid number, neutralization number or acidity) is a number used to quantify the acidity of a given chemical substance. It is the quantity of base (usually potassium hydroxide (KOH)), expressed as milligrams of KOH required to neutralize the acidic constituents in 1 gram of a sample.The acid number is a measure of the number of carboxylic acid groups (−C(=O)OH) in a chemical compound, such as a fatty acid, or in a mixture of compounds. In other words, it is a measure of free fatty acids (FFAs) present in a substance. In a typical procedure, a known amount of sample dissolved in an organic solvent (often isopropanol) and titrated with a solution of alcoholic potassium hydroxide (KOH) of known concentration using phenolphthalein as a colour indicator. The acid number for an oil sample is indicative of the age of the oil and can be used to determine when the oil must be changed.A liquid fat sample combined with neutralized 95% ethanol is titrated with standardized sodium hydroxide of 0.1 eq/L normality to a phenolphthalein endpoint. The volume and normality of the sodium hydroxide are used, along with the weight of the sample, to calculate the free fatty acid value.Acid value is usually measured as milligrams of KOH per gram of sample (mg KOH/g fat/oil), or grams of KOH per gram of sample (g KOH/g fat/oil).
Mechanical impact Summary Mechanical_impact A high-velocity collision (an impact) does not provide sufficient time for these deformations and vibrations to occur. Thus, the struck material behaves as if it were more brittle than it would otherwise be, and the majority of the applied force goes into fracturing the material. Or, another way to look at it is that materials actually are more brittle on short time scales than on long time scales: this is related to time-temperature superposition.
Optical scattering Single and multiple scattering Scattering_process > Single and multiple scattering Similarly, multiple scattering can sometimes have somewhat random outcomes, particularly with coherent radiation. The random fluctuations in the multiply scattered intensity of coherent radiation are called speckles. Speckle also occurs if multiple parts of a coherent wave scatter from different centers.
Epitranscriptome Long non-coding RNA (lncRNA) Epitranscriptome > Modifications specific to different types of RNA > Long non-coding RNA (lncRNA) The family of long non-coding RNAs includes a variety of different kinds of RNA, including, but not limited to, circular RNA (circRNA), nuclear lncRNA, long intergenic non-coding RNA, and enhancer RNA. The development of next-generation sequencing has made the study of lncRNA more accessible (because lncRNA is not very common in the cell relative to other types of RNA). Editing and modifications to lncRNA have demonstrated to result in changes in RNA expression and rate of mutation. 5-methylcytosine (m5C), N6-methyladenosine (m6A), and pseudouridine are the three most common and most studied modifications occurring in lncRNA.
Geography of disability Discrimination in law and policy Geography_of_disability > Discrimination in law and policy During the shift to virtual spaces for work and schooling during the COVID-19 public-health emergency in early 2020, a number of disability advocates noted that many disabled workers have been denied telecommuting technology as companies cite cost control. Several countries have enacted policies to address discrimination against people with disabilities. According to a WHO report about disability barriers,Beliefs and prejudices constitute barriers to education, employment, health care, and social participation. For example, the attitudes of teachers, school administrators, other children, and even family members affect the inclusion of children with disabilities in mainstream schools.
Ampere balance Summary Ampere_balance A more complicated version of an Ampere balance, called the Kibble balance, that removes this source of inaccuracy by a calibration step, was invented by Bryan Kibble in 1975. This experimental device was developed at government metrology laboratories worldwide with the goal of providing a more accurate definition of the kilogram, the world's standard of mass. In this application, the Kibble balance functions in the reverse sense to the Ampere balance: it is used to weigh the International Prototype of the Kilogram, defining the kilogram in terms of an electric current and a voltage. Since voltage and current themselves are already defined in terms of fundamental physical constants like Planck's constant and the speed of light, this has created a new definition of the kilogram in terms of these fundamental constants. This is a more stable definition than the previous one, which was based on the physical prototype kilogram which is vulnerable to damage and deterioration over the years.
Acetyl-CoA Intermediates in various pathways Acetyl-coenzyme_A > Functions > Intermediates in various pathways In Cellular Respiration Citric acid cycle: Through a series of chemical reactions, stored energy is released through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins into adenosine triphosphate (ATP) and carbon dioxide. Fatty acid metabolism Acetyl-CoA is produced by the breakdown of both carbohydrates (by glycolysis) and lipids (by β-oxidation). It then enters the citric acid cycle in the mitochondrion by combining with oxaloacetate to form citrate. Two acetyl-CoA molecules condense to form acetoacetyl-CoA, which gives rise to the formation of acetoacetate and β-hydroxybutyrate.
Nonelementary Integral Properties Nonelementary_Integral > Properties Nonelementary antiderivatives can often be evaluated using Taylor series. Even if a function has no elementary antiderivative, its Taylor series can always be integrated term-by-term like a polynomial, giving the antiderivative function as a Taylor series with the same radius of convergence. However, even if the integrand has a convergent Taylor series, its sequence of coefficients often has no elementary formula and must be evaluated term by term, with the same limitation for the integral Taylor series. Even if it is not possible to evaluate an indefinite integral (antiderivative) in elementary terms, one can always approximate a corresponding definite integral by numerical integration.
Philosophy of motion Quantum physics Philosophy_of_motion > Modern > Quantum physics Questions of the nature of motion continue to arise in modern physics, with many of the issues of concern to early thinkers arising in different form. Heisenberg's uncertainty principle and the clinamen of the Epicureans.
Visual attention Neuropsychological model Visual_attention > Neuropsychological model In this volume, Luria summarized his three-part global theory of the working brain as being composed of three constantly co-active processes which he described as the; (1) Attention system, (2) Mnestic (memory) system, and (3) Cortical activation system. The two books together are considered by Homskaya's account as "among Luria's major works in neuropsychology, most fully reflecting all the aspects (theoretical, clinical, experimental) of this new discipline." The product of the combined research of Vygotsky and Luria have determined a large part of the contemporary understanding and definition of attention as it is understood at the start of the 21st-century.
Glossary of genetics (M–Z) M Glossary_of_genetics_(M–Z) > M In molecular biology, any laboratory technique by which one or more genetic mutations are deliberately engineered in order to produce a mutant gene, regulatory element, gene product, or genetically modified organism so that the functions of a genetic locus, process, or product can be studied in detail. mutant An organism, gene product, or phenotypic trait resulting from a mutation, of a type that would not be observed naturally in wild-type specimens. mutation Any permanent change in the nucleotide sequence of a strand of DNA or RNA, or in the amino acid sequence of a peptide.
Imipenem/cilastatin Mechanism of liver injury Imipenem/cilastatin > Side effects > Mechanism of liver injury The cause of the mild, transient serum enzyme elevations during imipenem-cilastatin therapy is not known. The cholestatic hepatitis attributed to imipenem-cilastatin and the carbapenems is probably immunoallergic and resembles the rare, clinically apparent liver injury that has been linked to penicillins and cephalosporins.
Identifier (computer languages) Summary Identifier_(computer_languages) In computer programming languages, an identifier is a lexical token (also called a symbol, but not to be confused with the symbol primitive data type) that names the language's entities. Some of the kinds of entities an identifier might denote include variables, data types, labels, subroutines, and modules.
Data cleansing Data quality Data_cleansing > Data quality The term foreign key is borrowed from relational database terminology. Regular expression patterns: Occasionally, text fields will have to be validated this way.
Callus (cell biology) Uses Callus_(cell_biology) > Uses Callus cells are not necessarily genetically homogeneous because a callus is often made from structural tissue, not individual cells. Nevertheless, callus cells are often considered similar enough for standard scientific analysis to be performed as if on a single subject. For example, an experiment may have half a callus undergo a treatment as the experimental group, while the other half undergoes a similar but non-active treatment as the control group. Plant calluses derived from many different cell types can differentiate into a whole plant, a process called regeneration, through addition of plant hormones to the culture medium.
Mechanism synthesis Gear teeth and gear train design Kinematic_synthesis > Gear teeth and gear train design The calculation of the speed ratios for a gear train with conjugate gear teeth becomes a calculation using the ratios of the radii of the pitch circles that make up the gear train.Gear train design uses the desired speed ratio for a system of gears to select the number of gears, their configuration, and the size of their pitch circles. This is independent of the selection of the gear teeth as long as the tooth profiles are conjugate, with the exception that the circumferences of the pitch circles must provide for a whole number of teeth. == References ==
Dgroups Brief history Dgroups > Brief history As none of the existing knowledge sharing applications were considered suitable, they decided to join forces and build their own system starting from an existing Bellanet platform. Dgroups is online since 2003. After having grown and matured in Bellanet/IDRC as a project, in March 2009 Dgroups members decided that an independent legal entity was needed at the heart of the partnership and the Dgroups Foundation was established in the Netherlands. The Dgroups Foundation now governs the development and running of the platform and related online services.
Functional differential equation Volterra's predator-prey model Functional_differential_equation > Application > Volterra's predator-prey model The Lotka–Volterra predator-prey model was originally developed to observe the population of sharks and fish in the Adriatic Sea; however, this model has been used in many other fields for different uses, such as describing chemical reactions. Modelling predatory-prey population has always been widely researched, and as a result, there have been many different forms of the original equation. One example, as shown by Xu, Wu (2013), of the Lotka–Volterra model with time-delay is given below: where p ( t ) {\displaystyle p(t)} denotes the prey population density at time t, P 1 ( t ) {\displaystyle P_{1}(t)} and P 2 ( t ) {\displaystyle P_{2}(t)} denote the density of the predator population at time t , r i , a i j ∈ C ( R , [ 0 , ∞ ) ) {\displaystyle t,r_{i},a_{ij}\in C(\mathbb {R} ,[0,\infty ))} and τ i j ∈ C ( R , R ) {\displaystyle \tau _{ij}\in C(\mathbb {R} ,\mathbb {R} )} Note that this model uses linear partial differential equations.
Sequential write Definition Sequential_access > Definition The canonical example is the linked list. Indexing into a list that has sequential access requires O(n) time, where n is the index. As a result, many algorithms such as quicksort and binary search degenerate into bad algorithms that are even less efficient than their naive alternatives; these algorithms are impractical without random access. On the other hand, some algorithms, typically those that do not have index, require only sequential access, such as mergesort, and face no penalty.
Cryptographic tableau Summary Cryptographic_tableau In cryptography, the tabula recta (from Latin tabula rēcta) is a square table of alphabets, each row of which is made by shifting the previous one to the left. The term was invented by the German author and monk Johannes Trithemius in 1508, and used in his Trithemius cipher.
Childhood schizophrenia Diagnosis Childhood_schizophrenia > Diagnosis In 2013, the American Psychiatric Association released the fifth edition of the DSM (DSM-5). According to the manual, to be diagnosed with schizophrenia, two diagnostic criteria have to be met over much of the time of a period of at least one month, with a significant impact on social or occupational functioning for at least six months. The DSM diagnostic criteria outlines that the person has to be experiencing either delusions, hallucinations, or disorganized speech. In other words, an individual does not have to be experiencing delusions or hallucinations to receive a diagnosis of schizophrenia.
Multiple myeloma Side effects Multiple_myeloma > Treatment > Side effects Chemotherapies and stem cell transplants can cause unwanted bleedings and may require platelet transfusions. It was seen that platelet transfusions for people undergoing a chemotherapy or a stem cell transplantation for the prevention of bleeding events had different effects on the number of participants with a bleeding event, the number of days on which a bleeding occurred, the mortality secondary to bleeding and the number of platelet transfusions depending on the way they were used (therapeutic, depending on a threshold, different dose schedules or prophylactic).
Prion protein Alzheimer's disease Prion_protein > Diseases caused by PrP misfolding > Alzheimer's disease In mice, this same deletion phenotypically varies between Alzheimer's mouse lines, as hAPPJ20 mice and TgCRND8 mice show a slight increase in epileptic activity, contributing to conflicting results when examining Alzheimer's survival rates. Of note, the deletion of PRNP in both APPswe and SEN1dE9, two other transgenic models of Alzheimer's, attenuated the epilepsy-induced death phenotype seen in a subset of these animals. Taken collectively, recent evidence suggests PRNP may be important for conducing the neurotoxic effects of soluble Aβ-oligomers and the emergent disease state of Alzheimer's.In humans, the methionine/valine polymorphism at codon 129 of PRNP (rs1799990) is most closely associated with Alzheimer's disease.
Baryon Summary Baryonic_particles Each baryon has a corresponding antiparticle (antibaryon) where their corresponding antiquarks replace quarks. For example, a proton is made of two up quarks and one down quark; and its corresponding antiparticle, the antiproton, is made of two up antiquarks and one down antiquark. Because they are composed of quarks, baryons participate in the strong interaction, which is mediated by particles known as gluons.
Electronic Control Unit Key elements Electronic_control_module > Key elements Core Microcontroller Memory SRAM EEPROM Flash Inputs Supply Voltage and Ground Digital inputs Analog inputs Outputs Actuator drivers (e.g. injectors, relays, valves) H bridge drivers for servomotors Logic outputs Communication links Housing Bus Transceivers, e.g. for K-Line, CAN, Ethernet Embedded Software Boot Loader Metadata for ECU and Software Identification, Version Management, Checksums Functional Software Routines Configuration Data
Irreversible inhibitor Metabolic regulation Irreversible_inhibition > Applications > Metabolic regulation A key step for the regulation of glycolysis is an early reaction in the pathway catalysed by phosphofructokinase‑1 (PFK1). When ATP levels rise, ATP binds an allosteric site in PFK1 to decrease the rate of the enzyme reaction; glycolysis is inhibited and ATP production falls. This negative feedback control helps maintain a steady concentration of ATP in the cell.
Thiazide diuretics Adverse effects Thiazide_diuretics > Adverse effects This activates the renin–angiotensin system, stimulates the secretion of aldosterone, thus activating Na+/K+-ATPase, increasing excretion of potassium in urine. Therefore, ACE inhibitor and thiazide combination is used to prevent hypokalemia. Hyperglycemia Hyperlipidemia Hyperuricemia Hypercalcemia Hyponatremia Hypomagnesemia Hypocalciuria
Nim (programming language) Compiler Nim_(programming_language) > Compiler This also allows writing applications for iOS and Android. There is also an unofficial LLVM backend, allowing use of the Nim compiler in a stand-alone way.The Nim compiler is self-hosting, meaning it is written in the Nim language. The compiler supports cross-compiling, so it is able to compile software for any of the supported operating systems, no matter the development machine. This is useful for compiling applications for embedded systems, and for uncommon and obscure computer architectures.
Nonlinear least squares Transformation to a linear model Non-linear_least_squares > Computation > Transformation to a linear model Another example of a linear approximation would be, when the model is a simple exponential function, it can be transformed into a linear model by taking logarithms. Graphically this corresponds to working on a semi-log plot. The sum of squares becomes This procedure should be avoided unless the errors are multiplicative and log-normally distributed because it can give misleading results.
Secular equation Characteristic polynomial of Ak Characteristic_polynomial > Characteristic polynomial of Ak If λ {\displaystyle \lambda } is an eigenvalue of a square matrix A {\displaystyle A} with eigenvector v , {\displaystyle \mathbf {v} ,} then λ k {\displaystyle \lambda ^{k}} is an eigenvalue of A k {\displaystyle A^{k}} because The multiplicities can be shown to agree as well, and this generalizes to any polynomial in place of x k {\displaystyle x^{k}}: That is, the algebraic multiplicity of λ {\displaystyle \lambda } in f ( A ) {\displaystyle f(A)} equals the sum of algebraic multiplicities of λ ′ {\displaystyle \lambda '} in A {\displaystyle A} over λ ′ {\displaystyle \lambda '} such that f ( λ ′ ) = λ . {\displaystyle f(\lambda ')=\lambda .} In particular, tr ⁡ ( f ( A ) ) = ∑ i = 1 n f ( λ i ) {\displaystyle \operatorname {tr} (f(A))=\textstyle \sum _{i=1}^{n}f(\lambda _{i})} and det ⁡ ( f ( A ) ) = ∏ i = 1 n f ( λ i ) . {\displaystyle \operatorname {det} (f(A))=\textstyle \prod _{i=1}^{n}f(\lambda _{i}).}
Minsky machine Formal definition Shepherdson–Sturgis_register_machine > Formal definition A (very) limited set of instructions: the instructions tend to divide into two classes: arithmetic and control. The instructions are drawn from the two classes to form "instruction-sets", such that an instruction set must allow the model to be Turing equivalent (it must be able to compute any partial recursive function). Arithmetic: arithmetic instructions may operate on all registers or on just a special register (e.g. accumulator).
Meridional overturning circulation Upwelling Meridional_overturning_circulation > Upwelling All these dense water masses sinking into the ocean basins displace the older deep-water masses that were made less dense by ocean mixing. To maintain a balance, water must be rising elsewhere. However, because this thermohaline upwelling is so widespread and diffuse, its speeds are very slow even compared to the movement of the bottom water masses. It is therefore difficult to measure where upwelling occurs using current speeds, given all the other wind-driven processes going on in the surface ocean.
Chromatin remodelling Specific functions Epigenetic_remodeling > Classification > ATP-dependent chromatin remodeling > Specific functions Several in-vitro experiments suggest that ISWI remodelers organize nucleosome into proper bundle form and create equal spacing between nucleosomes, whereas SWI/SNF remodelers disorder nucleosomes. The ISWI-family remodelers have been shown to play central roles in chromatin assembly after DNA replication and maintenance of higher-order chromatin structures. INO80 and SWI/SNF-family remodelers participate in DNA double-strand break (DSB) repair and nucleotide-excision repair (NER) and thereby plays crucial role in TP53 mediated DNA-damage response. NuRD/Mi-2/CHD remodeling complexes primarily mediate transcriptional repression in the nucleus and are required for the maintenance of pluripotency of embryonic stem cells.
Contraction (geometry) Firmly non-expansive mapping Contraction_(geometry) > Firmly non-expansive mapping The class of firmly non-expansive maps is closed under convex combinations, but not compositions. This class includes proximal mappings of proper, convex, lower-semicontinuous functions, hence it also includes orthogonal projections onto non-empty closed convex sets. The class of firmly nonexpansive operators is equal to the set of resolvents of maximally monotone operators.
TreeBASE Summary TreeBASE TreeBASE was a repository of phylogenetic data published in scientific journals. In phylogenetic studies, research data are collected or generated, such as comparative observations (e.g. character state matrices or multiple sequence alignments) made on a set of taxa, metadata about these taxa, and the phylogenetic trees that are inferred to best describe the evolutionary relationships between the taxa.
P ≠ NP Example P_=_NP_problem > Example Researchers have shown that many of the problems in NP have the extra property that a fast solution to any one of them could be used to build a quick solution to any other problem in NP, a property called NP-completeness. Decades of searching have not yielded a fast solution to any of these problems, so most scientists suspect that none of these problems can be solved quickly. This, however, has never been proven.
Continuous distribution Discrete probability distribution Absolutely_continuous_random_variable > Discrete probability distribution {\displaystyle n=1,2,...} , the sum of probabilities would be 1 / 2 + 1 / 4 + 1 / 8 + ⋯ = 1 {\displaystyle 1/2+1/4+1/8+\dots =1} . Well-known discrete probability distributions used in statistical modeling include the Poisson distribution, the Bernoulli distribution, the binomial distribution, the geometric distribution, the negative binomial distribution and categorical distribution. When a sample (a set of observations) is drawn from a larger population, the sample points have an empirical distribution that is discrete, and which provides information about the population distribution. Additionally, the discrete uniform distribution is commonly used in computer programs that make equal-probability random selections between a number of choices.
Coproduct (category theory) Summary Coproduct_(category_theory) In category theory, the coproduct, or categorical sum, is a construction which includes as examples the disjoint union of sets and of topological spaces, the free product of groups, and the direct sum of modules and vector spaces. The coproduct of a family of objects is essentially the "least specific" object to which each object in the family admits a morphism. It is the category-theoretic dual notion to the categorical product, which means the definition is the same as the product but with all arrows reversed. Despite this seemingly innocuous change in the name and notation, coproducts can be and typically are dramatically different from products.
Social ecological model Applications Social_ecological_model > Applications In personal health: to prevent illnesses, a person should avoid an environment in which they may be more susceptible to contracting a virus or where their immune system would be weakened. This also includes possibly removing oneself from a potentially dangerous environment or avoiding a sick coworker. On the other hand, some environments are particularly conducive to health benefits.
Completeness of the real numbers Forms of completeness Completeness_axiom > Forms of completeness The real numbers can be defined synthetically as an ordered field satisfying some version of the completeness axiom. Different versions of this axiom are all equivalent in the sense that any ordered field that satisfies one form of completeness satisfies all of them, apart from Cauchy completeness and nested intervals theorem, which are strictly weaker in that there are non Archimedean fields that are ordered and Cauchy complete. When the real numbers are instead constructed using a model, completeness becomes a theorem or collection of theorems.
Entropy Information theory Entropy > Approaches to understanding entropy > Information theory If W {\displaystyle W} is the number of microstates that can yield a given macrostate, and each microstate has the same a priori probability, then that probability is p = 1 / W {\displaystyle p=1/W} . The Shannon entropy (in nats) is H = − ∑ i = 1 W p i ln ⁡ p i = ln ⁡ W , {\displaystyle H=-\sum _{i=1}^{W}p_{i}\ln p_{i}=\ln W,} and if entropy is measured in units of k {\displaystyle k} per nat, then the entropy is given by H = k ln ⁡ W , {\displaystyle H=k\ln W,} which is the Boltzmann entropy formula, where k {\displaystyle k} is the Boltzmann constant, which may be interpreted as the thermodynamic entropy per nat. Some authors argue for dropping the word entropy for the H {\displaystyle H} function of information theory and using Shannon's other term, "uncertainty", instead.
Momentum Conservation in a continuum Conservation_of_Momentum > In deformable bodies and fluids > Conservation in a continuum Per unit volume, the rate of change in momentum is equal to ρDv/Dt. This is equal to the net force on the droplet. Forces that can change the momentum of a droplet include the gradient of the pressure and gravity, as above.
Natal Chart The Zodiac Horoscope > Concepts in Western astrology > The Zodiac The tropical zodiac defines the vernal point (the first day of spring in the northern hemisphere) as the first degree of Aries, but the sidereal zodiac allows it to precess. Many people are confused regarding the difference between the sidereal zodiac and the tropical zodiac signs. Because of a "wobble" in the Earth's axis of rotation over a period of about 26,000 years (often called a "great year"), the rate at which the vernal equinox precesses in the heavens is approximately 0 deg, 0 min, 50.23 seconds a year, drifting by one degree every 72 years.
Spindle cell Clinical significance Spindle_cell > Clinical significance Abnormal von Economo neuron development may be linked to several psychotic disorders, typically those characterized by distortions of reality, disturbances of thought, disturbances of language, and withdrawal from social contact. Altered von Economo neuron states have been implicated in both schizophrenia and autism, but research into these correlations remains at a very early stage. Frontotemporal dementia involves loss of mostly von Economo neurons. An initial study suggested that Alzheimer's disease specifically targeted von Economo neurons; this study was performed with end-stage Alzheimer brains in which cell destruction was widespread, but later it was found that Alzheimer's disease doesn't affect the von Economo neurons.
Conversational implicature Opting out of the cooperative principle Conversational_implicature > Conversational implicature > Opting out of the cooperative principle The cooperative principle and the maxims of conversation are not mandatory. A communicator can choose not to be cooperative; she can opt out of the cooperative principle by giving appropriate clues such as saying "My lips are sealed", or for example during a cross-examination at court. In such situations, no conversational implicatures arise.
Antiroll tanks Active antiroll tanks Antiroll_tanks > Active antiroll tanks The border between controlled-passive and active stabilisation is not that distinct. Active stabilisation generally implies that the system requires the use of machinery of significant power and the system must be much more effective in reducing roll in order to justify this high cost.
Natural Selection 2 Summary Natural_Selection_2 Natural Selection 2 is a multiplayer video game which combines first-person shooter and real-time strategy rules. It is set in a science fiction universe in which a human team fights an alien team for control of resources and territory in large and elaborate indoor facilities. It is the sequel to Natural Selection.
Hormonal medication Hormone-behavior interactions Hormone > Hormone-behavior interactions At the neurological level, behavior can be inferred based on hormone concentration, which in turn are influenced by hormone-release patterns; the numbers and locations of hormone receptors; and the efficiency of hormone receptors for those involved in gene transcription. Hormone concentration does not incite behavior, as that would undermine other external stimuli; however, it influences the system by increasing the probability of a certain event to occur.Not only can hormones influence behavior, but also behavior and the environment can influence hormone concentration. Thus, a feedback loop is formed, meaning behavior can affect hormone concentration, which in turn can affect behavior, which in turn can affect hormone concentration, and so on. For example, hormone-behavior feedback loops are essential in providing constancy to episodic hormone secretion, as the behaviors affected by episodically secreted hormones directly prevent the continuous release of said hormones.Three broad stages of reasoning may be used to determine if a specific hormone-behavior interaction is present within a system: The frequency of occurrence of a hormonally dependent behavior should correspond to that of its hormonal source. A hormonally dependent behavior is not expected if the hormonal source (or its types of action) is non-existent. The reintroduction of a missing behaviorally dependent hormonal source (or its types of action) is expected to bring back the absent behavior.
History of molecular theory 20th century History_of_molecular_theory > 20th century Their work was an influence on Pauling, who had just received his doctorate and visited Heitler and London in Zürich on a Guggenheim Fellowship. Subsequently, in 1931, building on the work of Heitler and London and on theories found in Lewis' famous article, Pauling published his ground-breaking article "The Nature of the Chemical Bond" (see: manuscript) in which he used quantum mechanics to calculate properties and structures of molecules, such as angles between bonds and rotation about bonds. On these concepts, Pauling developed hybridization theory to account for bonds in molecules such as CH4, in which four sp³ hybridised orbitals are overlapped by hydrogen's 1s orbital, yielding four sigma (σ) bonds.
Somatic cells Summary Vegetative_cell In cellular biology, a somatic cell (from Ancient Greek σῶμα (sôma) 'body'), or vegetal cell, is any biological cell forming the body of a multicellular organism other than a gamete, germ cell, gametocyte or undifferentiated stem cell. Such cells compose the body of an organism and divide through the process of binary fission and mitotic division. In contrast, gametes are cells that fuse during sexual reproduction, germ cells are cells that give rise to gametes, and stem cells are cells that can divide through mitosis and differentiate into diverse specialized cell types. For example, in mammals, somatic cells make up all the internal organs, skin, bones, blood and connective tissue, while mammalian germ cells give rise to spermatozoa and ova which fuse during fertilization to produce a cell called a zygote, which divides and differentiates into the cells of an embryo.
Axiom of Extensionality Interpretation Axiom_of_Extensionality > Interpretation We can then introduce a new symbol for A {\displaystyle A} ; it's in this way that definitions in ordinary mathematics ultimately work when their statements are reduced to purely set-theoretic terms. The axiom of extensionality is generally uncontroversial in set-theoretical foundations of mathematics, and it or an equivalent appears in just about any alternative axiomatisation of set theory. However, it may require modifications for some purposes, as below.
Noise-induced hearing loss Sound or stress training Noise-induced_hearing_loss > Prevention > Sound or stress training The study revealed that the stressor (sound, heat, or stress) conditioning increases the receptibility to glucocorticoid, a kind of anti-inflammatory hormone. The effects of glucocorticoid thus mitigate the inflammation from an acoustic trauma that can lead to hearing loss. In fact, high doses of corticoids are often prescribed by physicians after an acoustic-trauma in order to mitigate the inflammatory response.
Invariable plane Terminology and definition Invariable_plane > Terminology and definition This plane is sometimes called the "Laplacian" or "Laplace plane" or the "invariable plane of Laplace", though it should not be confused with the Laplace plane, which is the plane about which the individual orbital planes of planetary satellites precess. Both derive from the work of (and are at least sometimes named for) the French astronomer Pierre Simon Laplace. The two are equivalent only in the case where all perturbers and resonances are far from the precessing body. The invariable plane is derived from the sum of angular momenta, and is "invariable" over the entire system, while the Laplace plane for different orbiting objects within a system may be different. Laplace called the invariable plane the plane of maximum areas, where the "area" in this case is the product of the radius R and its time rate of change dR/dt, that is, its radial velocity, multiplied by the mass.
Improper axis of rotation Reflection through mirror planes Symmetry_operation > Molecules > Reflection through mirror planes If the plane of symmetry contains the principal axis of the molecule (i.e., the molecular z-axis), it is designated as a vertical mirror plane, which is indicated by a subscript v (σv). If the plane of symmetry is perpendicular to the principal axis, it is designated as a horizontal mirror plane, which is indicated by a subscript h (σh). If the plane of symmetry bisects the angle between two 2-fold axes perpendicular to the principal axis, it is designated as a dihedral mirror plane, which is indicated by a subscript d (σd).Through the reflection of each mirror plane, the molecule must be able to produce an identical image of itself.
Marine Sediment Texture Seafloor_sediments > Texture A high degree of sorting can also indicate maturity, because over time the smaller particles will be washed away, and a given amount of energy will move particles of a similar size over the same distance. Lastly, the older and more mature a sediment the higher the quartz content, at least in sediments derived from rock particles. Quartz is a common mineral in terrestrial rocks, and it is very hard and resistant to abrasion. Over time, particles made from other materials are worn away, leaving only quartz behind. Beach sand is a very mature sediment; it is composed primarily of quartz, and the particles are rounded and of similar size (well-sorted).
Unsupervised classification Method of moments Unsupervised_machine_learning > Probabilistic methods > Method of moments Latent variable models are statistical models where in addition to the observed variables, a set of latent variables also exists which is not observed. A highly practical example of latent variable models in machine learning is the topic modeling which is a statistical model for generating the words (observed variables) in the document based on the topic (latent variable) of the document. In the topic modeling, the words in the document are generated according to different statistical parameters when the topic of the document is changed.
Organosulfur compounds Sulfoxides, sulfones and thiosulfinates Organosulfur_compounds > Classes > Sulfoxides, sulfones and thiosulfinates A sulfoxide, R−S(O)−R, is the S-oxide of a sulfide ("sulfide oxide"), a sulfone, R−S(O)2−R, is the S,S-dioxide of a sulfide, a thiosulfinate, R−S(O)−S−R, is the S-oxide of a disulfide, and a thiosulfonate, R−S(O)2−S−R, is the S,S-dioxide of a disulfide. All of these compounds are well known with extensive chemistry, e.g., dimethyl sulfoxide, dimethyl sulfone, and allicin (see drawing).
Group (periodic table) CAS and old IUPAC numbering (A/B) Periodic_table_group > CAS and old IUPAC numbering (A/B) Two earlier group number systems exist: CAS (Chemical Abstracts Service) and old IUPAC. Both use numerals (Arabic or Roman) and letters A and B. Both systems agree on the numbers. The numbers indicate approximately the highest oxidation number of the elements in that group, and so indicate similar chemistry with other elements with the same numeral. The number proceeds in a linearly increasing fashion for the most part, once on the left of the table, and once on the right (see List of oxidation states of the elements), with some irregularities in the transition metals.
Current transformer Use Current_transformer > Use Under normal conditions, the current in the two circuit wires will be equal and flow in opposite directions, resulting in zero net current through the CT and no current in the secondary coil. If the supply current is redirected downstream into the third (ground) circuit conductor (e.g., if the grounded metallic case of a power tool contacts a 120-volt conductor), or into earth ground (e.g., if a person contacts a 120-volt conductor), the neutral return current will be less than the supply current, resulting in a positive net current flow through the CT. This net current flow will induce current in the secondary coil, which will cause the trip device to operate and de-energize the circuit - typically within 0.2 seconds.The burden (load) impedance should not exceed the specified maximum value to avoid the secondary voltage exceeding the limits for the current transformer. The primary current rating of a current transformer should not be exceeded, or the core may enter its non-linear region and ultimately saturate. This would occur near the end of the first half of each half (positive and negative) of the AC sine wave in the primary and compromise accuracy.
Pulse-Doppler radar Benefits Pulse-Doppler_radar > Principle > Benefits Sensitivity must be reduced near clutter to avoid overload. This vulnerability begins in the low-elevation region several beam widths above the horizon, and extends downward. This also exists throughout the volume of moving air associated with weather phenomenon.
Sporophyte Life cycle Sporophyte > Life cycle The sporophyte produces spores (hence the name) by meiosis, a process also known as "reduction division" that reduces the number of chromosomes in each spore mother cell by half. The resulting meiospores develop into a gametophyte. Both the spores and the resulting gametophyte are haploid, meaning they only have one set of chromosomes.
HIV transmission Summary Acquired_Immunodeficiency_Syndrome Without treatment a person living with HIV can expect to live for 11 years. Early testing can show if treatment is needed to stop this progression and to prevent infecting others. HIV is spread primarily by unprotected sex (including anal and vaginal sex), contaminated hypodermic needles or blood transfusions, and from mother to child during pregnancy, delivery, or breastfeeding.
Garbage disposal Operation Garbage_disposal > Operation Some covers manipulate a mechanical switch while others allow magnets in the cover to align with magnets in the unit. Small slits in the cover allow water to flow through. Batch feed models are considered safer, since the top of the disposal is covered during operation, preventing foreign objects from falling in.
Catalytic heater Functions Catalytic_heater > Functions Catalytic heaters serve many functions, especially in the oil and gas industries. They are useful where heat production is necessary at a controlled rate. Typically used in Thermoelectric Generators (TEG's or thermopiles) off of raw well gas or H2S to create enough electricity to operate the remote well site at great distances from their parent processing plants.
Non-radiative recombination Electron traps vs. hole traps Auger_Recombination > Non-radiative recombination > Shockley–Read–Hall (SRH) > Types of traps > Electron traps vs. hole traps Even though all the recombination events can be described in terms of electron movements, it is common to visualize the different processes in terms of excited electron and the electron holes they leave behind. In this context, if trap levels are close to the conduction band, they can temporarily immobilize excited electrons or in other words, they are electron traps. On the other hand, if their energy lies close to the valence band they become hole traps.
Impact of the COVID-19 pandemic on the military Summary Impact_of_the_COVID-19_pandemic_on_the_military The security and defence related aspects including the missions, operations and training were adversely affected with the Covid-19. The broad spread of Covid can limit the defence forces' ability to carry out a mission. Many military training and exercises have been postponed or cancelled.
Automation bias Automation-induced complacency Automation_bias > Automation-induced complacency It has been proposed, indeed, that the concepts of complacency and automation bias be combined into a single "integrative concept" because these two concepts "might represent different manifestations of overlapping automation-induced phenomena" and because "automation-induced complacency and automation bias represent closely linked theoretical concepts that show considerable overlap with respect to the underlying processes. "Automation complacency has been defined as "poorer detection of system malfunctions under automation compared with under manual control."
Analog automata Variant definitions of automata Theory_of_automata > Variant definitions of automata And, their relative expressive power? (Language hierarchy)Automata theory also studies the existence or nonexistence of any effective algorithms to solve problems similar to the following list: Does an automaton accept at least one input word?
POS tagger Dynamic programming methods Part-of-speech_tagging > History > Dynamic programming methods In 1987, Steven DeRose and Kenneth W. Church independently developed dynamic programming algorithms to solve the same problem in vastly less time. Their methods were similar to the Viterbi algorithm known for some time in other fields. DeRose used a table of pairs, while Church used a table of triples and a method of estimating the values for triples that were rare or nonexistent in the Brown Corpus (an actual measurement of triple probabilities would require a much larger corpus). Both methods achieved an accuracy of over 95%.
Scarlet fever Treatment Scarlet_fever > Treatment If the person is allergic to the family of antibiotics which both penicillin and amoxicillin are a part of (beta-lactam antibiotics), a first generation cephalosporin is used. Cephalosporin antibiotics, however, can still cause adverse reactions in people whose allergic reaction to penicillin is a Type 1 Hypersensitivity reaction. In those cases it is appropriate to choose clindamycin or erythromycin instead. Tonsillectomy, although once a reasonable treatment for recurrent streptococcal pharyngitis, is not indicated, as a person can still be infected with group A streptococcus without their tonsils.
Vibration isolation Common passive isolation systems Vibration_isolation > Passive isolation > Common passive isolation systems Base isolators for seismic isolation of buildings, bridges, etc. Base isolators made of layers of neoprene and steel with a low horizontal stiffness are used to lower the natural frequency of the building. Some other base isolators are designed to slide, preventing the transfer of energy from the ground to the building. Tuned mass dampers Tuned mass dampers reduce the effects of harmonic vibration in buildings or other structures.
Murine leukemia virus Replication cycle Murine_leukemia_virus > Replication cycle The viral DNA integrated into the host genome is called “provirus”. It is copied and translated by normal host-cell machinery.
Ocean surface wave Formation Wave_action > Formation Since the wind speed profile is logarithmic to the water surface, the curvature has a negative sign at this point. This relation shows the wind flow transferring its kinetic energy to the water surface at their interface. Assumptions: two-dimensional parallel shear flow incompressible, inviscid water and wind irrotational water slope of the displacement of the water surface is smallGenerally, these wave formation mechanisms occur together on the water surface and eventually produce fully developed waves.
Discriminative model Advantages Discriminative_model > Contrast with generative model > Advantages and disadvantages in application > Advantages Significant advantages of using discriminative modeling are: Higher accuracy, which mostly leads to better learning result. Allows simplification of the input and provides a direct approach to P ( y \| x ) {\displaystyle P(y\|x)} Saves calculation resource Generates lower asymptotic errorsCompared with the advantages of using generative modeling: Takes all data into consideration, which could result in slower processing as a disadvantage Requires fewer training samples A flexible framework that could easily cooperate with other needs of the application
Hydrogen isotope biogeochemistry Kinetic and equilibrium isotope effects Hydrogen_isotope_biogeochemistry > Physical chemistry > Kinetic and equilibrium isotope effects The stability of the lower energy drives the products to be enriched in deuterium relative to reactants. Conversely, under kinetic conditions, reactions are generally irreversible. The limiting step in the reaction is overcoming the activation energy barrier to reach an intermediate state.
DNS zone Forward DNS zones DNS_zone > Forward DNS zones DNS zones contain the records for mapping domain names to IP addresses or other information. The resolution of a domain name to its assigned information is also referred to as forward resolution, and the DNS zones associated with such processes are often referred to as forward zones. The term arose as the opposite of reverse zones, which are used for the reverse process: finding the DNS name associated with an IP address. Such reverse zones are maintained in the Internet Address and Routing Parameter Area (domain arpa). Another common use of the term forward zone refers to a specific configuration of DNS name servers, particularly caching name servers, in which resolution of a domain name is forwarded to another name server that is authoritative for the domain in question, rather than being answered from the established cache memory.
Refal programming language Factorial with loops Refal > Other examples > Factorial with loops Fact { s.n = ; }; Loop { 0 s.f = s.f; s.n s.f = <* s.n s.f>>; } As can be seen s.n acts as the loop counter.
Nuclear notation Chemical and molecular properties Isotope > Variation in properties between isotopes > Chemical and molecular properties (Heavy elements also have relatively more neutrons than lighter elements, so the ratio of the nuclear mass to the collective electronic mass is slightly greater.) There is also an equilibrium isotope effect. Similarly, two molecules that differ only in the isotopes of their atoms (isotopologues) have identical electronic structures, and therefore almost indistinguishable physical and chemical properties (again with deuterium and tritium being the primary exceptions). The vibrational modes of a molecule are determined by its shape and by the masses of its constituent atoms; so different isotopologues have different sets of vibrational modes. Because vibrational modes allow a molecule to absorb photons of corresponding energies, isotopologues have different optical properties in the infrared range.
Infrared signature Summary Infrared_signature Infrared signature, as used by defense scientists and the military, is the appearance of objects to infrared sensors. An infrared signature depends on many factors, including the shape and size of the object, temperature, and emissivity, reflection of external sources (earthshine, sunshine, skyshine) from the object's surface, the background against which it is viewed and the waveband of the detecting sensor. As such there is no all-encompassing definition of infrared signature nor any trivial means of measuring it. For example, the infrared signature of a truck viewed against a field will vary significantly with changing weather, time of day and engine loading. Two fairly successful examples of defining the infrared signature of an object are the apparent temperature difference at the sensor and the contrast radiant intensity (CRI) definitions.
Catalyst poisoning Hydrodesulfurization catalysts Catalyst_poisoning > Hydrodesulfurization catalysts In the purification of petroleum products, the process of hydrodesulfurization is utilized. Thiols, such as thiophene, are reduced using H2 to produce H2S and hydrocarbons of varying chain length. Common catalysts used are tungsten and molybdenum sulfide. Adding cobalt and nickel to either edges or partially incorporating them into the crystal lattice structure can improve the catalyst's efficiency. The synthesis of the catalyst creates a supported hybrid that prevents poisoning of the cobalt nuclei.
Phaedon Avouris Representative Publications Phaedon_Avouris > Representative Publications Lyo and Ph. Avouris (1989). "Negative Differential Resistance on the Atomic Scale: Implications for Atomic Scale Devices".
Nondeterministic finite automata Informal introduction Nondeterministic_Finite_Automaton > Informal introduction There are two ways to describe the behavior of an NFA, and both of them are equivalent. The first way makes use of the nondeterminism in the name of an NFA. For each input symbol, the NFA transitions to a new state until all input symbols have been consumed. In each step, the automaton nondeterministically "chooses" one of the applicable transitions.

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