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Department of Education and Science (United Kingdom) Summary Department_of_Education_and_Science_(United_Kingdom) The DfES was also represented in regional Government Offices. The DfES had jurisdiction only in England as education was the responsibility of the Scottish Government, Welsh Assembly Government and the Northern Ireland Assembly. On 28 June 2007, the DfES was split up into the Department for Children, Schools and Families (DCSF) and the Department for Innovation, Universities and Skills. The DCSF was later reorganised as the Department for Education in 2010.
John Randall (physicist) The Magnetron John_Randall_(physicist) > Career and research > The Magnetron This seemed to offer a much more likely path to higher power.The problem with existing magnetrons was not power, but efficiency. In the klystron, a beam of electrons was passed through a metal disk known as a resonator. The mechanical layout of the copper resonator caused it to influence the electrons, speeding them up and slowing them down, releasing microwaves.
Brans–Dicke theory Comparison with general relativity Brans–Dicke_theory > Comparison with general relativity Both Brans–Dicke theory and general relativity are examples of a class of relativistic classical field theories of gravitation, called metric theories. In these theories, spacetime is equipped with a metric tensor, g a b {\displaystyle g_{ab}} , and the gravitational field is represented (in whole or in part) by the Riemann curvature tensor R a b c d {\displaystyle R_{abcd}} , which is determined by the metric tensor. All metric theories satisfy the Einstein equivalence principle, which in modern geometric language states that in a very small region (too small to exhibit measurable curvature effects), all the laws of physics known in special relativity are valid in local Lorentz frames. This implies in turn that metric theories all exhibit the gravitational redshift effect.
Weird number Properties Weird_number > Properties If so, they must be greater than 1021.Sidney Kravitz has shown that for k a positive integer, Q a prime exceeding 2k, and R = 2 k Q − ( Q + 1 ) ( Q + 1 ) − 2 k {\displaystyle R={\frac {2^{k}Q-(Q+1)}{(Q+1)-2^{k}}}} also prime and greater than 2k, then n = 2 k − 1 Q R {\displaystyle n=2^{k-1}QR} is a weird number. With this formula, he found the large weird number n = 2 56 ⋅ ( 2 61 − 1 ) ⋅ 153722867280912929 ≈ 2 ⋅ 10 52 . {\displaystyle n=2^{56}\cdot (2^{61}-1)\cdot 153722867280912929\ \approx \ 2\cdot 10^{52}.}
Governance Internet governance Governance > Types > Internet governance Internet governance was defined by the World Summit on the Information Society as "the development and application by Governments, the private sector and civil society, in their respective roles, of shared principles, norms, rules, decision-making procedures, and programmes that shape the evolution and use of the Internet." Internet governance deals with how much influence each sector of society should have on the development of the Internet, such as to what extent the state should be able to censor it, and how issues on the Internet, such as cyber-bullying and criminal behavior should be approached.
Sulfur oxidizing bacteria Aerobic respiration Sulfur-oxidizing_bacteria > Aerobic respiration There are, however, several cases of aerobic archaea such as Haiobacterium, Thermoplasma, Sulfolobus and Yymbaculum. Most of the known eukaryotes carry out aerobic metabolism within their mithchondria which is an organelle that had a symbiogenesis origin from prokarya . All aerobic organisms contain oxidases of the cytochrome oxidase super family, but some members of the Pseudomonadota (E. coli and Acetobacter) can also use an unrelated cytochrome bd complex as a respiratory terminal oxidase.
Function key Windows/MS-DOS Function_Keys > Action on various programs and operating systems > Windows/MS-DOS F2 is used in many Windows applications such as Windows Explorer, Excel, Visual Studio and other programs to access file or field edit functions, such as renaming a file. F4 is used in some applications to make the window "fullscreen", like in 3D Pinball: Space Cadet. In Microsoft IE, it is used to view the URL list of previously viewed websites.
Outline of artificial intelligence Future Outline_of_artificial_intelligence > Future Transhumanism – philosophy of human transformation Posthumanism – people may survive, but not be recognizable in comparison to present modern-day humans. Cyborgs – Mind uploading – Existential risk from artificial general intelligence Global catastrophic risk § Artificial intelligence AI takeover – point at which humans are no longer the dominant form of intelligence on Earth and machine intelligence is Ethics of AI § Weaponization of artificial intelligence Artificial intelligence arms race – competition between two or more states to have its military forces equipped with the best "artificial intelligence" (AI). Lethal autonomous weapon Military robot Unmanned combat aerial vehicle Mitigating risks: AI safety AI control problem Friendly AI – hypothetical AI that is designed not to harm humans and to prevent unfriendly AI from being developed Machine ethics Regulation of AI AI box Self-replicating machines – smart computers and robots would be able to make more of themselves, in a geometric progression or via mass production. Or smart programs may be uploaded into hardware existing at the time (because linear architecture of sufficient speeds could be used to emulate massively parallel analog systems such as human brains). Hive mind – Robot swarm –
National Ambient Air Quality Standards Standards Federal_Equivalent_Method > Standards "EPA has set NAAQS for six major pollutants listed as below. These six are also the criteria air pollutants. ^a Each standard has its own criteria for how many times it may be exceeded ^b As of June 15, 2005, the 1-hour ozone standard no longer applies to areas designated with respect to the 8-hour ozone standard (which includes most of the United States, except for portions of 10 states). Source: USEPA
Multimedia learning Empirically established principles Multimedia_learning > Multimedia instructional design principles > Empirically established principles Common techniques include arrows, circles, highlighting or bolding text, and pausing or vocal emphasis in narration. Ending lesson segments after the critical information has been given may also serve as a signaling cue. Learner control principle: Deeper learning occurs when learners can control the rate at which they move forward through segmented content.
Social immunity Definition Social_immunity > Definition Sylvia Cremer defined social immunity in her seminal 2007 Current Biology paper 'Social Immunity' as the "collective action or altruistic behaviours of infected individuals that benefit the colony". She laid out a conceptual framework for the topic using examples from primates and eusocial insects. Cremer's definition focused on the collective benefits of behaviours and was adopted by other behavioural ecologists (e.g. Wilson-Rich 2009) when describing immune phenomena which were contingent on the action of multiple individuals. Cremer went on to develop a series of comparisons between personal and social immune systems—she explained that her definition of social immunity encompassed "the nature of these defences that they cannot be performed efficiently by single individuals, but depend strictly on the cooperation of at least two individuals".
Neutralization (chemistry) Meaning of "neutralization" Neutralization_reaction > Meaning of "neutralization" In the context of a chemical reaction the term neutralization is used for a reaction between an acid and a base or alkali. Historically, this reaction was represented as acid + base (alkali) → salt + waterFor example: HCl + NaOH → NaCl + H2OThe statement is still valid as long as it is understood that in an aqueous solution the substances involved are subject to dissociation, which changes the ionization state of the substances. The arrow sign, →, is used because the reaction is complete, that is, neutralization is a quantitative reaction. A more general definition is based on Brønsted–Lowry acid–base theory.
Range estimation Standard rulers Distance_measurement > Standard rulers The ruler the simplest kind of length measurement tool: lengths are defined by printed marks or engravings on a stick. The metre was initially defined using a ruler before more accurate methods became available. Gauge blocks are a common method for precise measurement or calibration of measurement tools.
Solar fuel Photochemical Solar_fuel > Hydrogen production > Photochemical In a photochemical process, the sunlight is directly used to split water into hydrogen and oxygen. Because the absorption spectrum of water does not overlap with the emission spectrum of the sun, direct dissociation of water cannot take place; a photosensitizer needs to be used. Several such catalysts have been developed as proof of concept, but not yet scaled up for commercial use; nevertheless, their relative simplicity gives the advantage of potential lower cost and increased energy conversion efficiency. One such proof of concept is the "artificial leaf" developed by Nocera and coworkers: a combination of metal oxide-based catalysts and a semiconductor solar cell produces hydrogen upon illumination, with oxygen as the only byproduct.
Parameter Mathematical analysis Parameter > Mathematical functions > Mathematical analysis In mathematical analysis, integrals dependent on a parameter are often considered. These are of the form F ( t ) = ∫ x 0 ( t ) x 1 ( t ) f ( x ; t ) d x . {\displaystyle F(t)=\int _{x_{0}(t)}^{x_{1}(t)}f(x;t)\,dx.} In this formula, t is the argument of the function F, and on the right-hand side the parameter on which the integral depends.
Boolean satisfiability problem Extensions of SAT Propositional_satisfiability > Extensions of SAT UNAMBIGUOUS-SAT is the name given to the satisfiability problem when the input is restricted to formulas having at most one satisfying assignment. The problem is also called USAT. A solving algorithm for UNAMBIGUOUS-SAT is allowed to exhibit any behavior, including endless looping, on a formula having several satisfying assignments.
Industrial Symbiosis Introduction Industrial_Symbiosis > Introduction IS systems such as the web of materials and energy exchanges among companies in Kalundborg, Denmark have spontaneously evolved from a series of micro innovations over a long time scale; however, the engineered design and implementation of such systems from a macro planner's perspective, on a relatively short time scale, proves challenging. Often, access to information on available by-products is difficult to obtain. These by-products are considered waste and typically not traded or listed on any type of exchange. Only a small group of specialized waste marketplaces addresses this particular kind of waste trading.
C-value enigma C-value enigma C-value_enigma > Variation among species > C-value enigma From where does this non-coding DNA come, and how is it spread and/or lost from genomes over time? What effects, or perhaps even functions, does this non-coding DNA have for chromosomes, nuclei, cells, and organisms? Why do some species exhibit remarkably streamlined chromosomes, while others possess massive amounts of non-coding DNA?
Tangent stiffness matrix Overview Tangent_stiffness_matrix > Overview Computational mechanics (CM) is interdisciplinary. Its three pillars are mechanics, mathematics, and computer science and physics.
Sign language Linguistics Sign_language > Linguistics As in spoken languages, these meaningless units are represented as (combinations of) features, although coarser descriptions are often also made in terms of five "parameters": handshape (or handform), orientation, location (or place of articulation), movement, and non-manual expression. (These meaningless units in sign languages were initially called cheremes, from the Greek word for hand, by analogy to the phonemes, from Greek for voice, of spoken languages. Now they are sometimes called phonemes when describing sign languages too, since the function is the same, but more commonly discussed in terms of "features" or "parameters".)
Bent's rule History Bent's_rule > History In the early 1930s, shortly after much of the initial development of quantum mechanics, those theories began to be applied towards molecular structure by Pauling, Slater, Coulson, and others. In particular, Pauling introduced the concept of hybridisation, where atomic s and p orbitals are combined to give hybrid sp, sp2, and sp3 orbitals. Hybrid orbitals proved powerful in explaining the molecular geometries of simple molecules like methane, which is tetrahedral with an sp3 carbon atom and bond angles of 109.5° between the four equivalent C-H bonds. However, slight deviations from these ideal geometries became apparent in the 1940s.
Physical space Spatial measurement Physical_space > Spatial measurement The measurement of physical space has long been important. Although earlier societies had developed measuring systems, the International System of Units, (SI), is now the most common system of units used in the measuring of space, and is almost universally used. Currently, the standard space interval, called a standard meter or simply meter, is defined as the distance traveled by light in vacuum during a time interval of exactly 1/299,792,458 of a second. This definition coupled with present definition of the second is based on the special theory of relativity in which the speed of light plays the role of a fundamental constant of nature.
Glossary of mechanical engineering D Glossary_of_mechanical_engineering > D Diode laser – Docking sleeve – Drafting – Drifting – Driveshaft – a component for transmitting mechanical power and torque and rotation, usually used to connect other components of a drivetrain that cannot be connected directly because of distance or the need to allow for relative movement between them. Dynamics – the branch of classical mechanics that is concerned with the study of forces and their effects on motion. Dynamometer – a device for simultaneously measuring the torque and rotational speed (RPM) of an engine, motor or other rotating prime mover so that its instantaneous power may be calculated.
Garbage can model Origins of the garbage can model Garbage_can_model > Origins of the garbage can model Ultimately, the search process ended with none of the potential candidates being chosen, and the head of the search committee taking the position of dean. During an interview, Olsen describes the chaotic decision-making process that he observed at the university throughout this search process, and how it served as a foundational experience for the three scholars to later collaborate and produce their model. Olsen explains in this interview how topics previously considered to be important to the decision-making process, such as if the actors were reasonable or rational, actually proved to be less important, and were instead trumped by issues such as time constraints of the participants involved.
Cattell–Horn–Carroll theory Cattell and Horn's Gf–Gc Model Cattell–Horn–Carroll_theory > Background > Development of the CHC model > Cattell and Horn's Gf–Gc Model Recent research has explored the idea that training on working memory tasks can transfer to improvements in fluid intelligence. (Jaeggi, 2008). This idea did not hold under further scrutiny (Melby-Lervåg, Redick, & Hulme, 2016).
Path of least resistance Description Path_of_least_resistance > Description In physics, the "path of least resistance" is a heuristic from folk physics that can sometimes, in very simple situations, describe approximately what happens. It is an approximation of the tendency to the least energy state. Other examples are "what goes up must come down" (gravity) and "heat goes from hot to cold" (second law of thermodynamics). But these simple descriptions are not derived from laws of physics and in more complicated cases these heuristics will fail to give even approximately correct results.
Noise margin Summary Noise_margin In electrical engineering, noise margin is the maximum voltage amplitude of extraneous signal that can be algebraically added to the noise-free worst-case input level without causing the output voltage to deviate from the allowable logic voltage level. It is commonly used in at least two contexts as follows: In communications system engineering, noise margin is the ratio by which the signal exceeds the minimum acceptable amount. It is normally measured in decibels. In a digital circuit, the noise margin is the amount by which the signal exceeds the threshold for a proper '0' (logic low) or '1' (logic high).
Sympathoadrenal system Summary Sympathoadrenal_system The sympathoadrenal system is a physiological connection between the sympathetic nervous system and the adrenal medulla and is crucial in an organism's physiological response to outside stimuli. When the body receives sensory information, the sympathetic nervous system sends a signal to preganglionic nerve fibers, which activate the adrenal medulla through acetylcholine. Once activated, norepinephrine and epinephrine are released directly into the blood by postganglionic nerve fibers where they act as the bodily mechanism for "fight-or-flight" responses. Because of this, the sympathoadrenal system plays a large role in maintaining glucose levels, sodium levels, blood pressure, and various other metabolic pathways that couple with bodily responses to the environment.
Depressed cubic Galois group Depressed_cubic > Galois group As Δ {\displaystyle {\sqrt {\Delta }}} changes of sign if two roots are exchanged, Δ {\displaystyle {\sqrt {\Delta }}} is fixed by the Galois group only if the Galois group is A3. In other words, the Galois group is A3 if and only if the discriminant is the square of an element of K. As most integers are not squares, when working over the field Q of the rational numbers, the Galois group of most irreducible cubic polynomials is the group S3 with six elements. An example of a Galois group A3 with three elements is given by p(x) = x3 − 3x − 1, whose discriminant is 81 = 92.
Feynman graph Motivation and history Interaction_vertex > Motivation and history This is closely tied to the functional integral formulation of quantum mechanics, also invented by Feynman—see path integral formulation. The naïve application of such calculations often produces diagrams whose amplitudes are infinite, because the short-distance particle interactions require a careful limiting procedure, to include particle self-interactions. The technique of renormalization, suggested by Ernst Stueckelberg and Hans Bethe and implemented by Dyson, Feynman, Schwinger, and Tomonaga compensates for this effect and eliminates the troublesome infinities. After renormalization, calculations using Feynman diagrams match experimental results with very high accuracy. Feynman diagram and path integral methods are also used in statistical mechanics and can even be applied to classical mechanics.
Dental antibiotic prophylaxis Recommendations Dental_antibiotic_prophylaxis > Recommendations Considerations should be undertaken by healthcare professional as well to exercise their clinical judgement and patient's consent in decision-making.Infective Endocarditis (IE) is the infection of heart valves.Previous beliefs were held that IE can be induced from dental procedures due to the invasive nature of treatment, therefore antibiotics were widely prescribed before dental treatment to prevent this. This belief has changed with evidence to show that the risk of IE occurrence from everyday routine such as toothbrushing and eating is the same as that of undergoing invasive dental procedure. Increasing concerns regarding rise in antibiotic resistance have also pushed for change in advice on antibiotic prophylaxis, where the British National Formulary (BNF) has now opposed the use of antibiotic prophylaxis in dentistry. Unsatisfactory evidence to conclude whether antibiotic prophylaxis is useful in patients at risk of IE before dental treatment.It is now established that ‘Antibiotic prophylaxis against IE is not recommended routinely for people undergoing dental procedures’ according to NICE 2016, recommendation 1.1.3.
Object-oriented languages Gang of Four design patterns Object_Oriented_Programming > Design patterns > Gang of Four design patterns Design Patterns: Elements of Reusable Object-Oriented Software is an influential book published in 1994 by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, often referred to humorously as the "Gang of Four". Along with exploring the capabilities and pitfalls of object-oriented programming, it describes 23 common programming problems and patterns for solving them. The book describes the following patterns: Creational patterns (5): Factory method pattern, Abstract factory pattern, Singleton pattern, Builder pattern, Prototype pattern Structural patterns (7): Adapter pattern, Bridge pattern, Composite pattern, Decorator pattern, Facade pattern, Flyweight pattern, Proxy pattern Behavioral patterns (11): Chain-of-responsibility pattern, Command pattern, Interpreter pattern, Iterator pattern, Mediator pattern, Memento pattern, Observer pattern, State pattern, Strategy pattern, Template method pattern, Visitor pattern
Kikuchi disease Pathophysiology Kikuchi_disease > Pathophysiology Some studies have suggested a genetic predisposition to the proposed autoimmune response. Several infectious candidates have been associated with Kikuchi disease.Many theories exist about the cause of KFD. Microbial/viral or autoimmune causes have been suggested.
Wave Other Wave > Mechanical waves > Other Waves of traffic, that is, propagation of different densities of motor vehicles, and so forth, which can be modeled as kinematic waves Metachronal wave refers to the appearance of a traveling wave produced by coordinated sequential actions.
METATOY Summary METATOY A METATOY is a sheet, formed by a two-dimensional array of small, telescopic optical components, that switches the path of transmitted light rays. METATOY is an acronym for "metamaterial for rays", representing a number of analogies with metamaterials; METATOYs even satisfy a few definitions of metamaterials, but are certainly not metamaterials in the usual sense. When seen from a distance, the view through each individual telescopic optical component acts as one pixel of the view through the METATOY as a whole. In the simplest case, the individual optical components are all identical; the METATOY then behaves like a homogeneous, but pixellated, window that can have very unusual optical properties (see the picture of the view through a METATOY).
Adhesive bonding Vehicle electronics Adhesive_bonding > Applications (selection) > Automotive industry > Vehicle electronics Many sensors are therefore encapsulated or protected by securely fitting housing. In both cases, adhesives are used.
4th Dimension (software) Data Types 4th_Dimension_(software) > Syntax > Data Types 4D fields, variables, and expressions can be of the following data types: More info on 4D data type can be found on the documentation page
Grid energy storage Superconducting magnetic energy Grid_storage > Forms > Superconducting magnetic energy The power conditioning system uses an inverter/rectifier to transform alternating current (AC) power to direct current or convert DC back to AC power. The inverter/rectifier accounts for about 2–3% energy loss in each direction.
Human influenza Epidemiology Influenza > Epidemiology Pandemic strains tend to be associated with higher rates of pneumonia in otherwise healthy individuals. Generally after each influenza pandemic, the pandemic strain continues to circulate as the cause of seasonal influenza, replacing prior strains. From 1700 to 1889, influenza pandemics occurred about once every 50–60 years. Since then, pandemics have occurred about once every 10–50 years, so they may be getting more frequent over time.
VHDL Design VHDL > Design VHDL is generally used to write text models that describe a logic circuit. Such a model is processed by a synthesis program, only if it is part of the logic design. A simulation program is used to test the logic design using simulation models to represent the logic circuits that interface to the design. This collection of simulation models is commonly called a testbench.
A* algorithm Optimality and consistency A_search_algorithm > Properties > Optimality and consistency Optimal efficiency is about the set of nodes expanded, not the number of node expansions (the number of iterations of A's main loop). When the heuristic being used is admissible but not consistent, it is possible for a node to be expanded by A* many times, an exponential number of times in the worst case. In such circumstances, Dijkstra's algorithm could outperform A* by a large margin. However, more recent research found that this pathological case only occurs in certain contrived situations where the edge weight of the search graph is exponential in the size of the graph and that certain inconsistent (but admissible) heuristics can lead to a reduced number of node expansions in A* searches.
Homomorphic filtering Image enhancement Homomorphic_filtering > Image enhancement Since illumination and reflectance combine multiplicatively, the components are made additive by taking the logarithm of the image intensity, so that these multiplicative components of the image can be separated linearly in the frequency domain. Illumination variations can be thought of as a multiplicative noise, and can be reduced by filtering in the log domain. To make the illumination of an image more even, the high-frequency components are increased and low-frequency components are decreased, because the high-frequency components are assumed to represent mostly the reflectance in the scene (the amount of light reflected off the object in the scene), whereas the low-frequency components are assumed to represent mostly the illumination in the scene. That is, high-pass filtering is used to suppress low frequencies and amplify high frequencies, in the log-intensity domain.
Mechanics of planar particle motion Fictitious forces in a local coordinate system Mechanics_of_planar_particle_motion > Fictitious forces in a local coordinate system Sitting on the particle, we adopt a non-inertial frame where the particle is at rest (zero velocity). This frame has a continuously changing origin, which at time t is the center of curvature (the center of the osculating circle in Figure 1) of the path at time t, and whose rate of rotation is the angular rate of motion of the particle about that origin at time t. This non-inertial frame also employs unit vectors normal to the trajectory and parallel to it. The angular velocity of this frame is the angular velocity of the particle about the center of curvature at time t. The centripetal force of the inertial frame is interpreted in the non-inertial frame where the body is at rest as a force necessary to overcome the centrifugal force.
Nutritional neuroscience Protein Nutritional_neuroscience > Protein The body normally interconverts amino acids to maintain homeostasis, but muscle protein can be catabolized to release amino acids during conditions of amino acid deficiency. Disruption of amino acid metabolism can affect brain development and neurophysiology to affect behavior. For example, fetal protein deficiency decreases the number of neurons in the CA1 region of the hippocampus.
Object modeling language Summary Object_modeling_language The UML began as an attempt by some of the major thought leaders in the community to define a standard language at the OOPSLA '95 Conference. Originally, Grady Booch and James Rumbaugh merged their models into a unified model. This was followed by Booch's company Rational Software purchasing Ivar Jacobson's Objectory company and merging their model into the UML.
Quantum artificial life Interactions Quantum_artificial_life > Artificial life on quantum computers > Interactions Interactions occur between individuals when the two take up the same space on the environmental grid. The presence of interactions between individuals provides an advantage for the shorter-lifespan individuals. When two individuals interact, exchanges of information between the two phenotypes may or may not occur based upon their existing values.
Kempner function Properties Kempner_function > Properties Since n {\displaystyle n} divides n ! {\displaystyle n!} , S ( n ) {\displaystyle S(n)} is always at most S ( n ) {\displaystyle S(n)} . A number n {\displaystyle n} greater than 4 is a prime number if and only if S ( n ) = n {\displaystyle S(n)=n} .
Streptococcus pyogenes Biofilm formation Group_A_beta-hemolytic_streptococcus > Bacteriology > Biofilm formation The mode of transportation out of the cell and the extracellular processing factor(s) are still unknown. The mature SHP pheromone can then be taken into nearby cells and the cell it originated from via a transmembrane protein, oligopeptide permease. In the cytosol the pheromones have two functions in the Rgg2/3 pathway.
Eyeline match Summary Eyeline_match An eyeline match is a film editing technique associated with the continuity editing system. It is based on the premise that an audience will want to see what the character on-screen is seeing. An eyeline match begins with a character looking at something off-screen, followed by a cut of another object or person: for example, a shot showing a man looking off-screen is followed by a shot of a television. Given the audience's initial interest in the man's gaze, it is generally implied on the basis of the second shot that the man in the first was looking at the television, even though the man is never seen looking at the television within the same shot.Alfred Hitchcock's Rear Window, for example, makes frequent use of eyeline matches.
Doppler radar Doppler effect Doppler_radar > Concept > Doppler effect Imagine a baseball pitcher throwing one ball every second to a catcher (a frequency of 1 ball per second). Assuming the balls travel at a constant velocity and the pitcher is stationary, the catcher catches one ball every second. However, if the pitcher is jogging towards the catcher, the catcher catches balls more frequently because the balls are less spaced out (the frequency increases).
Darzens reaction Stereochemistry Darzens_reaction > Reaction mechanism > Stereochemistry The initial stereochemistry of the reaction sequence is established in the step where the carbanion attacks the carbonyl. Two sp3 (tetrahedral) carbons are created at this stage, which allows two different diastereomeric possibilities of the halohydrin intermediate. The most likely result is due to chemical kinetics: whichever product is easier and faster to form will be the major product of this reaction.
Equilibrium temperature Greenhouse effect Planetary_equilibrium_temperature > Caveats > Greenhouse effect In the greenhouse effect, long wave radiation emitted by a planet is absorbed by certain gases in the atmosphere, reducing longwave emissions to space. Planets with substantial greenhouse atmospheres emit more longwave radiation at the surface than what reaches space. Consequently, such planets have surface temperatures higher than their effective radiation emission temperature. For example, Venus has an effective temperature of approximately 226 K (−47 °C; −53 °F), but a surface temperature of 740 K (467 °C; 872 °F). Similarly, Earth has an effective temperature of 255 K (−18 °C; −1 °F), but a surface temperature of about 288 K (15 °C; 59 °F) due to the greenhouse effect in our lower atmosphere. The surface temperatures of such planets are more accurately estimated by modeling thermal radiation transport through the atmosphere.
Postreplication repair Summary Postreplication_repair At damaged sites in the genome, both prokaryotic and eukaryotic cells utilize a number of postreplication repair (PRR) mechanisms to complete DNA replication. Chemically modified bases can be bypassed by either error-prone or error-free translesion polymerases, or through genetic exchange with the sister chromatid.
Immunological tolerance Summary Immunologic_tolerance Deficits in central or peripheral tolerance also cause autoimmune disease, resulting in syndromes such as systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes, autoimmune polyendocrine syndrome type 1 (APS-1), and immunodysregulation polyendocrinopathy enteropathy X-linked syndrome (IPEX), and potentially contribute to asthma, allergy, and inflammatory bowel disease. And immune tolerance in pregnancy is what allows a mother animal to gestate a genetically distinct offspring with an alloimmune response muted enough to prevent miscarriage. Tolerance, however, also has its negative tradeoffs. It allows for some pathogenic microbes to successfully infect a host and avoid elimination. In addition, inducing peripheral tolerance in the local microenvironment is a common survival strategy for a number of tumors that prevents their elimination by the host immune system.
Iconography of correlations Summary Iconography_of_correlations In exploratory data analysis, the iconography of correlations is a method which consists in replacing a correlation matrix by a diagram where the “remarkable” correlations are represented by a solid line (positive correlation), or a dotted line (negative correlation). This idea also appears in Gaussian graphic models used in particular in genome mapping. But the iconography of correlations is more general in that it does not make an assumption about the Gaussian distribution, or not, of the variables, and relies only on the geometric aspect of the Correlation coefficient. The first idea of the iconography of correlations dates back to 1975.
Phylogenetic relationship Phylogenetic tree shapes Insight on Disease Transmission Patterns Phylogenetic_relationship > Phylogenetic tree shapes Insight on Disease Transmission Patterns Additionally, coalescent theory, which describes probability distributions on trees based on population size, has been adapted for epidemiological purposes. Another potential source of information within phylogenies that has been explored is "tree shape". These approaches are computationally intensive but have the potential to provide valuable insights into pathogen transmission dynamics.
Electronic spectroscopy Wavelength error Ultraviolet_spectroscopy > Applications > Practical considerations > Wavelength error In liquids, the extinction coefficient usually changes slowly with wavelength. A peak of the absorbance curve (a wavelength where the absorbance reaches a maximum) is where the rate of change in absorbance with wavelength is smallest. Measurements are usually made at a peak to minimize errors produced by errors in wavelength in the instrument, that is errors due to having a different extinction coefficient than assumed.
Parameter Statistics and econometrics Parameter > Mathematical functions > Statistics and econometrics Similarly, the sample variance (estimator), denoted S2, can be used to estimate the variance parameter (estimand), denoted σ2, of the population from which the sample was drawn. (Note that the sample standard deviation (S) is not an unbiased estimate of the population standard deviation (σ): see Unbiased estimation of standard deviation.)
Endocrinology The endocrine system Endocrinology > The endocrine system Endocrinology is the study of the endocrine system in the human body. This is a system of glands which secrete hormones. Hormones are chemicals that affect the actions of different organ systems in the body.
T-duality Summary T-duality In theoretical physics, T-duality (short for target-space duality) is an equivalence of two physical theories, which may be either quantum field theories or string theories. In the simplest example of this relationship, one of the theories describes strings propagating in a spacetime shaped like a circle of some radius R {\displaystyle R} , while the other theory describes strings propagating on a spacetime shaped like a circle of radius proportional to 1 / R {\displaystyle 1/R} . The idea of T-duality was first noted by Bala Sathiapalan in an obscure paper in 1987. The two T-dual theories are equivalent in the sense that all observable quantities in one description are identified with quantities in the dual description.
Random mutation Summary Evolutionary_process Evolution by natural selection is established by observable facts about living organisms: (1) more offspring are often produced than can possibly survive; (2) traits vary among individuals with respect to their morphology, physiology, and behaviour; (3) different traits confer different rates of survival and reproduction (differential fitness); and (4) traits can be passed from generation to generation (heritability of fitness). In successive generations, members of a population are therefore more likely to be replaced by the offspring of parents with favourable characteristics for that environment. In the early 20th century, competing ideas of evolution were refuted and evolution was combined with Mendelian inheritance and population genetics to give rise to modern evolutionary theory.
Hash-based cryptography History Hash-based_cryptography > History Leslie Lamport invented hash-based signatures in 1979. The XMSS (eXtended Merkle Signature Scheme) and SPHINCS hash-based signature schemes were introduced in 2011 and 2015, respectively. XMSS was developed by a team of researchers under the direction of Johannes Buchmann and is based both on Merkle's seminal scheme and on the 2007 Generalized Merkle Signature Scheme (GMSS). A multi-tree variant of XMSS, XMSSMT, was described in 2013.
Restitution coefficient Colliding different materials and practical measurement Restitution_coefficient > Speeds after impact > Colliding different materials and practical measurement When a soft object strikes a harder object, most of the energy available for the post-collision velocity will be stored in the soft object. The COR will depend on how efficient the soft object is at storing the energy in compression without losing it to heat and plastic deformation. A rubber ball will bounce better off concrete than a glass ball, but the COR of glass-on-glass is a lot higher than rubber-on-rubber because some of the energy in rubber is lost to heat when it is compressed. When a rubber ball collides with a glass ball, the COR will depend entirely on the rubber.
RNA timestamp Summary RNA_timestamp An RNA timestamp is a technology that enables the age of any given RNA transcript to be inferred by exploiting RNA editing. In this technique, the RNA of interest is tagged to an adenosine rich reporter motif that consists of multiple MS2 binding sites. These MS2 binding sites recruit a complex composed of ADAR2 (adenosine deaminase acting on RNA catalytic 2 domain) and MCP (MS2 capsid protein).
Glossary of biology E Glossary_of_biology > E entomology The scientific study of insects. environmental biology The branch of biology concerned with the relations between organisms and their environments. enzyme A protein that acts as a biological catalyst by accelerating chemical reactions.
Moment distribution method Result Moment_distribution > Example > Result Moments at joints determined by the moment distribution method M A = 0 k N ⋅ m {\displaystyle M_{A}=0\ kN\cdot m} M B = − 11.569 k N ⋅ m {\displaystyle M_{B}=-11.569\ kN\cdot m} M C = − 10.186 k N ⋅ m {\displaystyle M_{C}=-10.186\ kN\cdot m} M D = − 13.657 k N ⋅ m {\displaystyle M_{D}=-13.657\ kN\cdot m} The conventional engineer's sign convention is used here, i.e. positive moments cause elongation at the bottom part of a beam member.For comparison purposes, the following are the results generated using a matrix method. Note that in the analysis above, the iterative process was carried to >0.01 precision. The fact that the matrix analysis results and the moment distribution analysis results match to 0.001 precision is mere coincidence. Moments at joints determined by the matrix method M A = 0 k N ⋅ m {\displaystyle M_{A}=0\ kN\cdot m} M B = − 11.569 k N ⋅ m {\displaystyle M_{B}=-11.569\ kN\cdot m} M C = − 10.186 k N ⋅ m {\displaystyle M_{C}=-10.186\ kN\cdot m} M D = − 13.657 k N ⋅ m {\displaystyle M_{D}=-13.657\ kN\cdot m} Note that the moment distribution method only determines the moments at the joints. Developing complete bending moment diagrams require additional calculations using the determined joint moments and internal section equilibrium.
Crystal Crystal structure (microscopic) Crystalline_rock > Crystal structure (microscopic) The unit cells are stacked in three-dimensional space to form the crystal. The symmetry of a crystal is constrained by the requirement that the unit cells stack perfectly with no gaps. There are 219 possible crystal symmetries (230 is commonly cited, but this treats chiral equivalents as separate entities), called crystallographic space groups. These are grouped into 7 crystal systems, such as cubic crystal system (where the crystals may form cubes or rectangular boxes, such as halite shown at right) or hexagonal crystal system (where the crystals may form hexagons, such as ordinary water ice).
Variance analysis (accounting) Variance analysis Variance_analysis_(accounting) > Variance analysis Variance analysis, first used in ancient Egypt, in budgeting or management accounting in general, is a tool of budgetary control by evaluation of performance by means of variances between budgeted amount, planned amount or standard amount and the actual amount incurred/sold. Variance analysis can be carried out for both costs and revenues. Variance analysis is usually associated with explaining the difference (or variance) between actual costs and the standard costs allowed for the good output. For example, the difference in materials costs can be divided into a materials price variance and a materials usage variance.
Disability and poverty Current initiatives Disability_and_poverty > Current initiatives The movement asserts that unless these obstacles are rectified, the connection between disability and poverty will persist.Employment is seen as a critical agent in reducing stigma and increasing capacity in the lives of individuals with disabilities. The lack of opportunities currently available is shown to perpetuate the vicious cycle, causing individuals with disabilities to fall into poverty. To address these concerns many recent initiatives have begun to develop more inclusive employment structures.
Matter waves Molecules De_Broglie_Hypothesis > Introduction > Experimental confirmation > Molecules More recent experiments prove the quantum nature of molecules made of 810 atoms and with a mass of 10123 Da. As of 2019, this has been pushed to molecules of 25000 Da.In these experiments the build-up of such interference patterns could be recorded in real time and with single molecule sensitivity. Large molecules are already so complex that they give experimental access to some aspects of the quantum-classical interface, i.e., to certain decoherence mechanisms.
James Clerk Maxwell King's College, London, 1860–1865 James_Clerk_Maxwell > Life > King's College, London, 1860–1865 In it he provided a conceptual model for electromagnetic induction, consisting of tiny spinning cells of magnetic flux. Two more parts were later added to and published in that same paper in early 1862. In the first additional part he discussed the nature of electrostatics and displacement current. In the second additional part, he dealt with the rotation of the plane of the polarisation of light in a magnetic field, a phenomenon that had been discovered by Faraday and is now known as the Faraday effect.
Allergic to penicillin Penicillin G Allergic_to_penicillin > Medical usage > Penicillin G Penicillin G is destroyed by stomach acid, so it cannot be taken by mouth, but doses as high as 2.4 g can be given (much higher than penicillin V). It is given by intravenous or intramuscular injection. It can be formulated as an insoluble salt, and there are two such formulations in current use: procaine penicillin and benzathine benzylpenicillin, which are used only in the treatment of syphilis. When a high concentration in the blood must be maintained, penicillin G must be administered at relatively frequent intervals, because it is eliminated quite rapidly from the bloodstream by the kidney. Penicillin G is licensed for use to treat septicaemia, empyema, pneumonia, pericarditis, endocarditis and meningitis caused by susceptible strains of staphylococci and streptococci. It is also licensed for the treatment of anthrax, actinomycosis, cervicofacial disease, thoracic and abdominal disease, clostridial infections, botulism, gas gangrene (with accompanying debridement and/or surgery as indicated), tetanus (as an adjunctive therapy to human tetanus immune globulin), diphtheria (as an adjunctive therapy to antitoxin and for the prevention of the carrier state), erysipelothrix endocarditis, fusospirochetosis (severe infections of the oropharynx, lower respiratory tract and genital area), Listeria infections, meningitis, endocarditis, Pasteurella infections including bacteraemia and meningitis, Haverhill fever; rat-bite fever and disseminated gonococcal infections, meningococcal meningitis and/or septicaemia caused by penicillin-susceptible organisms and syphilis.
Dyslexia Assessment tests Dyslexia > Diagnosis > Assessment > Assessment tests Examples include the Behavioral Assessment System for Children, and the Strengths and Difficulties Questionnaire. All of these have nationally representative norms, making it possible to compare the level of symptoms to what would be typical for the younger person's age and biological sex. Other checklists link more specifically to psychiatric diagnoses, such as the Vanderbilt ADHD Rating Scales or the Screen for Child Anxiety Related Emotional Disorders (SCARED).
Link prediction Katz measure Link_prediction > Approaches and methods > Topology-based methods > Katz measure The powers of A indicate the presence (or absence) of links between two nodes through intermediaries. For instance, in matrix A 3 {\displaystyle A^{3}} , if element ( a 2 , 12 ) = 1 {\displaystyle (a_{2,12})=1} , it indicates that node 2 and node 12 are connected through some walk of length 3. If C K a t z ( i ) {\displaystyle C_{\mathrm {Katz} }(i)} denotes Katz centrality of a node i, then mathematically: C K a t z ( i ) = ∑ k = 1 ∞ ∑ j = 1 n α k ( A k ) j i {\displaystyle C_{\mathrm {Katz} }(i)=\sum _{k=1}^{\infty }\sum _{j=1}^{n}\alpha ^{k}(A^{k})_{ji}} Note that the above definition uses the fact that the element at location ( i , j ) {\displaystyle (i,j)} of A k {\displaystyle A^{k}} reflects the total number of k {\displaystyle k} degree connections between nodes i {\displaystyle i} and j {\displaystyle j} .
Supply and demand Equilibrium Supply_and_demand > Microeconomics > Equilibrium (A movement along the curve is described as a "change in the quantity demanded" to distinguish it from a "change in demand," that is, a shift of the curve.) The increase in demand has caused an increase in (equilibrium) quantity. The increase in demand could come from changing tastes and fashions, incomes, price changes in complementary and substitute goods, market expectations, and number of buyers.
Steady-state error Controller theory Steady-state_error > Controller theory This section describes the parallel or non-interacting form of the PID controller. For other forms please see § Alternative nomenclature and forms.The PID control scheme is named after its three correcting terms, whose sum constitutes the manipulated variable (MV). The proportional, integral, and derivative terms are summed to calculate the output of the PID controller. Defining u ( t ) {\displaystyle u(t)} as the controller output, the final form of the PID algorithm is u ( t ) = M V ( t ) = K p e ( t ) + K i ∫ 0 t e ( τ ) d τ + K d d e ( t ) d t , {\displaystyle u(t)=\mathrm {MV} (t)=K_{\text{p}}e(t)+K_{\text{i}}\int _{0}^{t}e(\tau )\,d\tau +K_{\text{d}}{\frac {de(t)}{dt}},} where K p {\displaystyle K_{\text{p}}} is the proportional gain, a tuning parameter, K i {\displaystyle K_{\text{i}}} is the integral gain, a tuning parameter, K d {\displaystyle K_{\text{d}}} is the derivative gain, a tuning parameter, e ( t ) = S P − P V ( t ) {\displaystyle e(t)=\mathrm {SP} -\mathrm {PV} (t)} is the error (SP is the setpoint, and PV(t) is the process variable), t {\displaystyle t} is the time or instantaneous time (the present), τ {\displaystyle \tau } is the variable of integration (takes on values from time 0 to the present t {\displaystyle t} ).Equivalently, the transfer function in the Laplace domain of the PID controller is L ( s ) = K p + K i / s + K d s , {\displaystyle L(s)=K_{\text{p}}+K_{\text{i}}/s+K_{\text{d}}s,} where s {\displaystyle s} is the complex frequency.
Jet pack Yves Rossy's jet wingpack Jet_suit > Turbojet packs > Yves Rossy's jet wingpack After being lifted to altitude by a plane, he ignites the engines just before he exits the plane with the wings folded. The wings unfold while in free-fall, and he then can fly horizontally for several minutes, landing with the help of a parachute. He achieves true controlled flight using his body and a hand throttle to maneuver.
Soft power Description Soft_power > Description Soft power resources are the assets that produce attraction, which often leads to acquiescence. Nye asserts that, "Seduction is always more effective than coercion, and many values like democracy, human rights, and individual opportunities are deeply seductive." Angelo Codevilla observed that an often overlooked essential aspect of soft power is that different parts of populations are attracted or repelled by different things, ideas, images, or prospects.
Mental fog In diseases Mental_fog > In diseases Many of these are also common symptoms of ADHD (attention deficit hyperactivity disorder), and the two conditions have been linked via studies, to the point that a diagnosis of fibromyalgia has been proposed as an indication to also screen for ADHD. It is alternatively hypothesized that the increased pain compromises attention systems, resulting in cognitive problems.In chronic fatigue syndrome, also known as myalgic encephalomyelitis, the CDC's recommended criteria for diagnosis include that one of the following symptoms must be present: Problems with thinking and memory (cognitive dysfunction, sometimes described as "brain fog") While standing or sitting upright; lightheadedness, dizziness, weakness, fainting or vision changes may occur (orthostatic intolerance)Lyme disease's neurologic syndrome, called Lyme encephalopathy, is associated with subtle memory and cognitive difficulties, among other issues. Lyme can cause a chronic encephalomyelitis that resembles multiple sclerosis.
History of the International System of Units Derived units History_of_the_International_System_of_Units > Units and prefixes > Derived units This has the effect that the distinction between the base units and derived units is, in principle, not needed, since all units, base as well as derived, may be constructed directly from the defining constants. Nevertheless, the distinction is retained because "it is useful and historically well established", and also because the ISO/IEC 80000 series of standards specifies base and derived quantities that necessarily have the corresponding SI units. : 129 The derived units in the SI are formed by powers, products, or quotients of the base units and are potentially unlimited in number.
Lethal autonomous weapon Possible violations of ethics and international acts Autonomous_weapon_systems > Ethical and legal issues > Possible violations of ethics and international acts Stuart Russell, professor of computer science from University of California, Berkeley stated the concern he has with LAWs is that his view is that it is unethical and inhumane. The main issue with this system is it is hard to distinguish between combatants and non-combatants.There is concern by some economists and legal scholars about whether LAWs would violate International Humanitarian Law, especially the principle of distinction, which requires the ability to discriminate combatants from non-combatants, and the principle of proportionality, which requires that damage to civilians be proportional to the military aim. This concern is often invoked as a reason to ban "killer robots" altogether - but it is doubtful that this concern can be an argument against LAWs that do not violate International Humanitarian Law.A 2021 report by the American Congressional Research Service states that "there are no domestic or international legal prohibitions on the development of use of LAWs," although it acknowledges ongoing talks at the UN Convention on Certain Conventional Weapons (CCW).LAWs are said by some to blur the boundaries of who is responsible for a particular killing. Philosopher Robert Sparrow argues that autonomous weapons are causally but not morally responsible, similar to child soldiers.
Annus mirabilis papers Special relativity Annus_mirabilis_papers > Papers > Special relativity First, he applies the principle of relativity, which states that the laws of physics remain the same for any non-accelerating frame of reference (called an inertial reference frame), to the laws of electrodynamics and optics as well as mechanics. In the second postulate, Einstein proposes that the speed of light has the same value in all frames of reference, independent of the state of motion of the emitting body. Special relativity is thus consistent with the result of the Michelson–Morley experiment, which had not detected a medium of conductance (or aether) for light waves unlike other known waves that require a medium (such as water or air), and which had been crucial for the development of the Lorentz transformations and the principle of relativity.
Detailed balance Microscopic background Detailed_balance_equations > Microscopic background Equilibrium may be not T- or PT-invariant even if the laws of motion are invariant. This non-invariance may be caused by the spontaneous symmetry breaking. There exist nonreciprocal media (for example, some bi-isotropic materials) without T and PT invariance.If different macroscopic processes are sampled from the same elementary microscopic events then macroscopic detailed balance may be violated even when microscopic detailed balance holds.Now, after almost 150 years of development, the scope of validity and the violations of detailed balance in kinetics seem to be clear.
Structural proteomics Summary Structural_genomics Structural genomics seeks to describe the 3-dimensional structure of every protein encoded by a given genome. This genome-based approach allows for a high-throughput method of structure determination by a combination of experimental and modeling approaches. The principal difference between structural genomics and traditional structural prediction is that structural genomics attempts to determine the structure of every protein encoded by the genome, rather than focusing on one particular protein. With full-genome sequences available, structure prediction can be done more quickly through a combination of experimental and modeling approaches, especially because the availability of large number of sequenced genomes and previously solved protein structures allows scientists to model protein structure on the structures of previously solved homologs.
Argument scheme Argument from ignorance Argumentation_scheme > Examples > Argument from ignorance The scheme and its accompanying critical questions are shown below. : 327 These critical questions, CQ2 and CQ3 especially, show the dialectical nature of the theory from which this scheme derives (that is, the scheme is based on a back and forth exchange between different parties). Two dialectical concerns are considered.
Quantum processing unit Candidates for physical realizations Quantum_processing_unit > Engineering > Candidates for physical realizations A practical quantum computer must use a physical system as a programmable quantum register. Researchers are exploring several technologies as candidates for reliable qubit implementations. Superconductors and trapped ions are some of the most developed proposals, but experimentalists are considering other hardware possibilities as well.
Algebraic graph theory Using linear algebra Algebraic_graph_theory > Branches of algebraic graph theory > Using linear algebra The first branch of algebraic graph theory involves the study of graphs in connection with linear algebra. Especially, it studies the spectrum of the adjacency matrix, or the Laplacian matrix of a graph (this part of algebraic graph theory is also called spectral graph theory). For the Petersen graph, for example, the spectrum of the adjacency matrix is (−2, −2, −2, −2, 1, 1, 1, 1, 1, 3).
Stream function Summary Stream_function The stream function is defined for incompressible (divergence-free) flows in two dimensions – as well as in three dimensions with axisymmetry. The flow velocity components can be expressed as the derivatives of the scalar stream function. The stream function can be used to plot streamlines, which represent the trajectories of particles in a steady flow. The two-dimensional Lagrange stream function was introduced by Joseph Louis Lagrange in 1781.
Gastrointestinal symptom Hepatic Gastrointestinal_disorder > Accessory digestive gland disease > Hepatic Portal hypertension is often present, and this may lead to the development of prominent veins in many parts of the body, such as oesophageal varices, and haemorrhoids. : 959–963, 971–973 In order to investigate liver disease, a medical history, including regarding a person's family history, travel to risk-prone areas, alcohol use and food consumption, may be taken. A medical examination may be conducted to investigate for symptoms of liver disease.
Corpuscular theory of light Isaac Newton Corpuscular_theory_of_light > Isaac Newton The material point is the only representative of reality in so far as it is subject to change. The concept of the material point is obviously due to observable bodies; one conceived of the material point on the analogy of movable bodies by omitting characteristics of extension, form, spatial locality, and all their 'inner' qualities, retaining only inertia, translation, and the additional concept of force. Every source of light emits large numbers of tiny particles known as corpuscles in a medium surrounding the source. These corpuscles are perfectly elastic, rigid, and weightless.
An Essay on the Application of Mathematical Analysis to the Theories of Electricity and Magnetism Overview An_Essay_on_the_Application_of_Mathematical_Analysis_to_the_Theories_of_Electricity_and_Magnetism > Overview Green's 1828 essay was neglected by mathematicians till 1846, and before that time most of its important theorems had been rediscovered by Gauss, Chasles, Sturm, and Thomson J. It did influence the work of Lord Kelvin and James Clerk Maxwell. The self-taught mathematician's essay was one of the greatest advances that were made in the mathematical theory of electricity up to his time. "His researches," as Sir William Thomson has observed, "have led to the elementary proposition which must constitute the legitimate foundation of every perfect mathematical structure that is to be made from the materials furnished in the experimental laws of Coulomb.
Proofs of elementary ring properties Multiplication by zero Proofs_of_elementary_ring_properties > Basics > Multiplication by zero Theorem: 0 ⋅ a = a ⋅ 0 = 0 {\displaystyle 0\cdot a=a\cdot 0=0}
Neuroblast Differentiation Neuroblast > Formation > Differentiation Transit amplifying cells are slightly more differentiated than neural stem cells and can divide asymmetrically to produce postmitotic neuroblasts and glioblasts, as well as other transit amplifying cells. A neuroblast, a daughter cell of a transit amplifying cell, is initially a neural stem cell that has reached the "point of no return." A neuroblast has differentiated such that it will mature into a neuron and not any other neural cell type. Neuroblasts are being studied extensively as they have the potential to be used therapeutically to combat cell loss due to injury or disease in the brain, although their potential effectiveness is debated.
Google Public DNS Summary Google_Public_DNS Google Public DNS is a Domain Name System (DNS) service offered to Internet users worldwide by Google. It functions as a recursive name server. Google Public DNS was announced on December 3, 2009, in an effort described as "making the web faster and more secure." As of 2018, it is the largest public DNS service in the world, handling over a trillion queries per day. Google Public DNS is not related to Google Cloud DNS, which is a DNS hosting service.
Airflow Airflow in mechanical ventilation systems (HVAC) Airflow > Airflow in buildings > Airflow in mechanical ventilation systems (HVAC) Mechanical ventilation uses fans to induce flow of air into and through a building. Duct configuration and assembly affect air flow rates through the system. Dampers, valves, joints and other geometrical or material changes within a duct can lead to flow pressure (energy) losses.
Human mitochondrial genome Damage and transcription error Human_mitochondrial_genome > Replication, repair, transcription, and translation > Damage and transcription error Both cases can lead to deletions, rearrangements, and other mutations. Recent evidence has suggested that mitochondria have enzymes that proofread mtDNA and fix mutations that may occur due to free radicals. It is believed that a DNA recombinase found in mammalian cells is also involved in a repairing recombination process.
Translational partition function Summary Translational_partition_function The factor of N! arises from the restriction of allowed N particle states due to Quantum exchange symmetry. Most substances form liquids or solids at temperatures much higher than when this approximation breaks down significantly.
Time integral Functional integrals Sum_rule_in_integration > Extensions > Functional integrals An integration that is performed not over a variable (or, in physics, over a space or time dimension), but over a space of functions, is referred to as a functional integral.
Parallel algorithms for minimum spanning trees Summary Parallel_algorithms_for_minimum_spanning_trees It is not necessarily unique. More generally, graphs that are not necessarily connected have minimum spanning forests, which consist of a union of MSTs for each connected component. As finding MSTs is a widespread problem in graph theory, there exist many sequential algorithms for solving it.
Approximation Etymology and usage Approximate_inequality > Etymology and usage An approximate model is used to make calculations easier. Approximations might also be used if incomplete information prevents use of exact representations. The type of approximation used depends on the available information, the degree of accuracy required, the sensitivity of the problem to this data, and the savings (usually in time and effort) that can be achieved by approximation.

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