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Dynamic strain aging Material property effects Dynamic_strain_aging > Material property effects Although serrations in the stress–strain curve caused by the Portevin–Le Chatelier effect are the most visible effect of dynamic strain aging, other effects may be present when this effect is not seen. Often when serrated flow is not seen, dynamic strain aging is marked by a lower strain rate sensitivity. That becomes negative in the Portevin–Le Chatelier regime. Dynamic strain aging also causes a plateau in the strength, a peak in flow stress a peak in work hardening, a peak in the Hall–Petch constant, and minimum variation of ductility with temperature. Since dynamic strain aging is a hardening phenomenon it increases the strength of the material.
Diagrammatic reasoning Logical graph Diagrammatic_reasoning > Logical graph A logical graph is a special type of graph-theoretic structure in any one of several systems of graphical syntax that Charles Sanders Peirce developed for logic. In his papers on qualitative logic, entitative graphs, and existential graphs, Peirce developed several versions of a graphical formalism, or a graph-theoretic formal language, designed to be interpreted for logic. In the century since Peirce initiated this line of development, a variety of formal systems have branched out from what is abstractly the same formal base of graph-theoretic structures.
Proper reference frame (flat spacetime) Textbooks Proper_reference_frame_(flat_spacetime) > Bibliography > Textbooks Synge, J.L. (1960). Relativity: the general theory.
Slater's rules Motivation Slater's_rules > Motivation Such a form was inspired by the known wave function spectrum of hydrogen-like atoms which have the radial component R n l ( r ) = r l f n l ( r ) exp ⁡ ( − Z r n ) , {\displaystyle R_{nl}(r)=r^{l}f_{nl}(r)\exp \left(-{\frac {Zr}{n}}\right),} where n is the (true) principal quantum number, l the azimuthal quantum number, and fnl(r) is an oscillatory polynomial with n - l - 1 nodes. Slater argued on the basis of previous calculations by Clarence Zener that the presence of radial nodes was not required to obtain a reasonable approximation. He also noted that in the asymptotic limit (far away from the nucleus), his approximate form coincides with the exact hydrogen-like wave function in the presence of a nuclear charge of Z-s and in the state with a principal quantum number n equal to his effective quantum number n*.
Electrometer Summary Electrometer An electrometer is an electrical instrument for measuring electric charge or electrical potential difference. There are many different types, ranging from historical handmade mechanical instruments to high-precision electronic devices. Modern electrometers based on vacuum tube or solid-state technology can be used to make voltage and charge measurements with very low leakage currents, down to 1 femtoampere. A simpler but related instrument, the electroscope, works on similar principles but only indicates the relative magnitudes of voltages or charges.
Direct-drive sim racing wheel Control electronics Direct_drive_wheel > Construction > Control electronics Other than the motor, other parts of a complete direct drive wheel base include a rotary encoder (the position sensor), a controller board (that translate the FFB data from the game into steering wheel forces), and a motor driver board (servo drive), which fits into a slot of the controller board, and that controls the position, velocity and torque output of the motor. Examples of encoders are the Biss-C and the SinCos encoders, an example of a controller board is the Simucube board, and some examples of motor driver boards are the IONI and the Argon ones.
Voltage control and reactive power management Absorption and production of reactive power Voltage_control > Absorption and production of reactive power However, in the case of a short on the load side, the capacitor will be briefly exposed to the full line voltage, thus protection circuits are provisioned, usually involving spark gaps, ZnO varistors, and switches; active compensators (e.g., synchronous condensers, static var compensators, static synchronous compensators that can be either sources or sinks of reactive power; regulating transformers (e.g., tap-changing transformers).The passive compensation devices can be permanently attached, or are switched (connected and disconnected) either manually, using a timer, or automatically based on sensor data. The active devices are by nature self-adjusting.
SDR SDRAM Virtual channel memory (VCM) SDRAM Prefetch_buffer > Failed successors > Virtual channel memory (VCM) SDRAM VCM was a proprietary type of SDRAM that was designed by NEC, but released as an open standard with no licensing fees. It is pin-compatible with standard SDRAM, but the commands are different. The technology was a potential competitor of RDRAM because VCM was not nearly as expensive as RDRAM was.
Overlearning Early studies Overlearning > Early studies Memory researcher Hermann Ebbinghaus performed classical overlearning studies in the late 1890s. He noticed that memory for learned material decreased over time (see also forgetting curve). Ebbinghaus recognized that lists of nonsense syllables became more difficult to recall over time, and some lists required more review time to regain 100% recall. He defined overlearning as the number of repetitions of material after which it can be recalled with 100% accuracy.
PLS (complexity) List of PLS-complete Problems PLS_(complexity) > PLS-completeness > List of PLS-complete Problems Metric-TSP/Lin-Kernighan has been proven to be PLS-complete via a tight PLS-reduction from Max-2Sat/Flip to Metric-TSP/Lin-Kernighan. Local-Multi-Processor-Scheduling/k-change has been proven to be PLS-complete via a tight PLS-reduction from Weighted-3Dimensional-Matching/(p, q)-Swap to Local-Multi-Processor-scheduling/(2p+q)-change, where (2p + q) ≥ 8. Selfish-Multi-Processor-Scheduling/k-change-with-property-t has been proven to be PLS-complete via a tight PLS-reduction from Weighted-3Dimensional-Matching/(p, q)-Swap to (2p+q)-Selfish-Multi-Processor-Scheduling/k-change-with-property-t, where (2p + q) ≥ 8.
Paleopathology Tuberculosis Paleopathology > Methods and techniques > Archaeological infectious diseases > Tuberculosis Tuberculosis rarely manifests itself in the skeleton of individuals and when it does, it is usually only in advanced stages of the disease. The tuberculosis bacteria stays in the growth centers and spongy areas of the bone. This disease has a very long period of maturation, or the time it takes the disease to reach its full destructive potential.
Nephritic syndrome Treatment Nephritic_syndrome > Treatment This will cause excess fluids to be excreted in the urine and may lessen the workload placed on the kidney, allowing it to recover from the inflammatory damage. Administration of antihypertensives to alleviate hypertension and maintain a normal blood pressure during the recovery process. Administration of anti-inflammatory medications (such as steroids or NSAIDs) to reduce active inflammation in the kidney. If the patient is showing signs of kidney failure or end-organ damage, the treatment team may opt to utilize kidney dialysis temporarily (or permanently, in some severe cases) to decrease stress on the kidneys and allow for optimal recovery.Once the acute phase of the nephritic syndrome is controlled, it is crucial to determine the underlying pathology that caused the onset of the acute nephritic syndrome and to treat that condition. If the underlying cause is not determined and treated appropriately, it increases the risk of a recurrence of nephritic syndrome or chronic kidney disease (CKD) in the future.
Domain (function) Other uses Domain_of_a_function > Other uses The term domain is also commonly used in a different sense in mathematical analysis: a domain is a non-empty connected open set in a topological space. In particular, in real and complex analysis, a domain is a non-empty connected open subset of the real coordinate space R n {\displaystyle \mathbb {R} ^{n}} or the complex coordinate space C n . {\displaystyle \mathbb {C} ^{n}.} Sometimes such a domain is used as the domain of a function, although functions may be defined on more general sets. The two concepts are sometimes conflated as in, for example, the study of partial differential equations: in that case, a domain is the open connected subset of R n {\displaystyle \mathbb {R} ^{n}} where a problem is posed, making it both an analysis-style domain and also the domain of the unknown function(s) sought.
Hardening (metallurgy) Processes Hardening_(metallurgy) > Processes The plastic straining generates new dislocations. As the dislocation density increases, further dislocation movement becomes more difficult since they hinder each other, which means the material hardness increases. In solid solution strengthening, a soluble alloying element is added to the material desired to be strengthened, and together they form a “solid solution”.
Screw (simple machine) Handedness Screw_(simple_machine) > Handedness In some devices that have threads on either end, like turnbuckles and removable pipe segments. These parts have one right-handed and one left-handed thread, so that turning the piece tightens or loosens both threads at the same time. In some gas supply connections to prevent dangerous misconnections.
Iterated integral Summary Repeated_integral {\displaystyle \int \left(\int f(x,y)\,dx\right)\,dy.} It is key for the notion of iterated integrals that this is different, in principle, from the multiple integral ∬ f ( x , y ) d x d y . {\displaystyle \iint f(x,y)\,dx\,dy.}
Distance oracle Introduction Distance_oracle > Introduction This structure allows us to answer queries in constant time O ( 1 ) {\displaystyle O(1)} , but requires O ( n 2 ) {\displaystyle O(n^{2})} extra space. It can be initialized in time O ( n 3 ) {\displaystyle O(n^{3})} using an all-pairs shortest paths algorithm, such as the Floyd–Warshall algorithm. A DO lies between these two extremes. It uses less than O ( n 2 ) {\displaystyle O(n^{2})} space in order to answer queries in less than O ( m + n log ⁡ n ) {\displaystyle O(m+n\log n)} time. Most DOs have to compromise on accuracy, i.e. they don't return the accurate distance but rather a constant-factor approximation of it.
Oncomodulin Mechanism of Action Oncomodulin > Mechanism of Action It is also unknown whether oncomodulin promotes regeneration elsewhere in the immune system. Signaling complexes that may be important to work with oncomodulin include PI 3 Kinase, MAP Kinase, JAK/STAT, and CaM Kinase II.
Photosynthesis system Applications Integrated_fluorometer > Applications Their research suggests that the combined effects of heat and drought stress cause sucrose to serve as the major osmoprotectant. Plant physiologists from The University of Putra Malaysia and The University of Edinburgh investigated the relative effects of tree age and tree size on the physiological attributes of two broadleaf species. A photosynthetic system was used to measure photosynthetic rate per unit of leaf mass.
Byte Units based on powers of 10 Petabyte > Multiple-byte units > Units based on powers of 10 Definition of prefixes using powers of 10—in which 1 kilobyte (symbol kB) is defined to equal 1,000 bytes—is recommended by the International Electrotechnical Commission (IEC). The IEC standard defines eight such multiples, up to 1 yottabyte (YB), equal to 10008 bytes. The additional prefixes ronna- for 10009 and quetta- for 100010 were adopted by the International Bureau of Weights and Measures (BIPM) in 2022.This definition is most commonly used for data-rate units in computer networks, internal bus, hard drive and flash media transfer speeds, and for the capacities of most storage media, particularly hard drives, flash-based storage, and DVDs. Operating systems that use this definition include macOS, iOS, Ubuntu, and Debian. It is also consistent with the other uses of the SI prefixes in computing, such as CPU clock speeds or measures of performance.
Eukaryotic DNA replication Termination Eukaryotic_DNA_replication > Termination Termination of eukaryotic DNA replication requires different processes depending on whether the chromosomes are circular or linear. Unlike linear molecules, circular chromosomes are able to replicate the entire molecule. However, the two DNA molecules will remain linked together. This issue is handled by decatenation of the two DNA molecules by a type II topoisomerase.
Capacitor electric vehicle Motor racing Capacitor_electric_vehicle > Motor racing The FIA, the governing body for many motor racing events, proposed in the Power-Train Regulation Framework for Formula 1 version 1.3 of 23 May 2007 that a new set of power train regulations be issued that includes a hybrid drive of up to 200 kW input and output power using "superbatteries" made with both batteries and supercapacitors.
Eye tracker Optical tracking Commercial_eye_tracking > Tracker types > Optical tracking A more sensitive type of eye-tracker, the dual-Purkinje eye tracker, uses reflections from the front of the cornea (first Purkinje image) and the back of the lens (fourth Purkinje image) as features to track. A still more sensitive method of tracking is to image features from inside the eye, such as the retinal blood vessels, and follow these features as the eye rotates. Optical methods, particularly those based on video recording, are widely used for gaze-tracking and are favored for being non-invasive and inexpensive.
Simplicity theory Overview Simplicity_theory > Overview Technically, simplicity corresponds in a drop in Kolmogorov complexity, which means that, for an observer, the shortest description of the situation is shorter than anticipated. For instance, the description of a consecutive lottery draw, such as 22-23-24-25-26-27, is significantly shorter than a typical one, such as 12-22-27-37-38-42. The former requires only one instantiation (choice of the first lottery number), whereas the latter requires six instantiations. Simplicity theory makes several quantitative predictions concerning the way atypicality, distance, recency or prominence (places, individuals) influence interestingness.
Medical microbiology Microscopy Clinical_microbiology > Diagnostic tests > Microscopy Both techniques help give more detailed information about the structure of microbes. This makes it useful in many medical fields, such as diagnostics and biopsies of many body parts, hygiene, and virology. They provide critical information about the structure of pathogens, which allow physicians to treat them with more knowledge.
Static structure Summary Static_structure The application of the assumption of zero acceleration to the summation of moments acting on the system leads to M = I α = 0 {\displaystyle {\textbf {M}}=I\alpha =0} , where M {\displaystyle {\textbf {M}}} is the summation of all moments acting on the system, I {\displaystyle I} is the moment of inertia of the mass and α {\displaystyle \alpha } is the angular acceleration of the system. For a system where α = 0 {\displaystyle \alpha =0} , it is also true that M = 0. {\displaystyle {\textbf {M}}=0.} Together, the equations F = m a = 0 {\displaystyle {\textbf {F}}=m{\textbf {a}}=0} (the 'first condition for equilibrium') and M = I α = 0 {\displaystyle {\textbf {M}}=I\alpha =0} (the 'second condition for equilibrium') can be used to solve for unknown quantities acting on the system.
Gas filled tube Noble gases Discharge_tube > Gases in use > Noble gases Noble gases are frequently used in tubes for many purposes, from lighting to switching. Pure noble gases are employed in switching tubes. Noble-gas-filled thyratrons have better electrical parameters than mercury-based ones. The electrodes undergo damage by high-velocity ions.
Rhodium chloride Alkenes and carbon monoxide Rhodium(III)_chloride > Coordination complexes > Alkenes and carbon monoxide Unlike most other air-stable metal salts, hydrated rhodium trichloride reacts under mild conditions (near room temperature, one atmosphere) with carbon monoxide and many olefins. This behavior opens the doors to extensive inventory of organorhodium compounds. Most of these substrates cause reduction of rhodium(III) to rhodium(I). The resulting Rh(I) complexes engage the carbon-based ligands by pi-backbonding.
Quantum Computation Language Examples Quantum_Computation_Language > Examples The basic built-in quantum data type in QCL is the qureg (quantum register). It can be interpreted as an array of qubits (quantum bits). Since the qcl interpreter uses qlib simulation library, it is possible to observe the internal state of the quantum machine during execution of the quantum program. Note that the dump operation is different from measurement, since it does not influence the state of the quantum machine and can be realized only using a simulator.
Fermi liquid theory Specific heat and compressibility Fermi_liquid_theory > Differences from Fermi gas > Specific heat and compressibility Specific heat, compressibility, spin-susceptibility and other quantities show the same qualitative behaviour (e.g. dependence on temperature) as in the Fermi gas, but the magnitude is (sometimes strongly) changed.
Joule Practical examples Joule_(unit) > Practical examples One joule represents (approximately): The amount of electricity required to run a 1 W device for 1 s. The energy required to accelerate a 1 kg mass at 1 m/s2 through a distance of 1 m. The kinetic energy of a 2 kg mass travelling at 1 m/s, or a 1 kg mass travelling at 1.41 m/s. The energy required to lift an apple up 1 m, assuming the apple has a mass of 101.97 g. The heat required to raise the temperature of 0.239 g of water from 0 °C to 1 °C. The typical energy released as heat by a person at rest every 1/60 s (17 ms).
Gravity of Earth Estimating g from the law of universal gravitation Gravity_of_Earth > Estimating g from the law of universal gravitation It does not include the reduction of constraint force that we perceive as a reduction of gravity due to the rotation of Earth, and some of gravity being counteracted by centrifugal force.There are significant uncertainties in the values of r and m1 as used in this calculation, and the value of G is also rather difficult to measure precisely. If G, g and r are known then a reverse calculation will give an estimate of the mass of the Earth. This method was used by Henry Cavendish.
Fibrous capsule of Glisson Other Liver_metabolism > Functions > Other The liver helps in the purification of blood. The Kupffer cells of liver are phagocytic cells, helps in phagocytosis of dead blood cells and bacteria from the blood. The liver is responsible for immunological effects – the mononuclear phagocyte system of the liver contains many immunologically active cells, acting as a 'sieve' for antigens carried to it via the portal system.
Neoplastic transformation Cancer as a defect in cell interactions Cancer_induction > Cancer cell biology > Cancer as a defect in cell interactions Normally, once a tissue is injured or infected, damaged cells elicit inflammation by stimulating specific patterns of enzyme activity and cytokine gene expression in surrounding cells. Discrete clusters ("cytokine clusters") of molecules are secreted, which act as mediators, inducing the activity of subsequent cascades of biochemical changes. Each cytokine binds to specific receptors on various cell types, and each cell type responds in turn by altering the activity of intracellular signal transduction pathways, depending on the receptors that the cell expresses and the signaling molecules present inside the cell. Collectively, this reprogramming process induces a stepwise change in cell phenotypes, which will ultimately lead to restoration of tissue function and toward regaining essential structural integrity.
Adenosine diphosphate Catabolism Adenosine_diphosphate > Cellular respiration > Catabolism The ten-step catabolic pathway of glycolysis is the initial phase of free-energy release in the breakdown of glucose and can be split into two phases, the preparatory phase and payoff phase. ADP and phosphate are needed as precursors to synthesize ATP in the payoff reactions of the TCA cycle and oxidative phosphorylation mechanism. During the payoff phase of glycolysis, the enzymes phosphoglycerate kinase and pyruvate kinase facilitate the addition of a phosphate group to ADP by way of substrate-level phosphorylation.
Combline filter Feedforward form Comb_filter > Continuous time implementation > Feedforward form The feedforward form may be described by the equation: y ( t ) = x ( t ) + α x ( t − τ ) {\displaystyle y(t)=x(t)+\alpha x(t-\tau )} where τ is the delay (measured in seconds). This has the following transfer function: H ( s ) = 1 + α e − s τ {\displaystyle H(s)=1+\alpha e^{-s\tau }} The feedforward form consists of an infinite number of zeros spaced along the jω axis (which corresponds to the Fourier domain).
Opposition effect Summary Opposition_surge The opposition surge (sometimes known as the opposition effect, opposition spike or Seeliger effect) is the brightening of a rough surface, or an object with many particles, when illuminated from directly behind the observer. The term is most widely used in astronomy, where generally it refers to the sudden noticeable increase in the brightness of a celestial body such as a planet, moon, or comet as its phase angle of observation approaches zero. It is so named because the reflected light from the Moon and Mars appear significantly brighter than predicted by simple Lambertian reflectance when at astronomical opposition. Two physical mechanisms have been proposed for this observational phenomenon: shadow hiding and coherent backscatter.
Multiple factor analysis Example Multiple_factor_analysis > Balance between groups of variables > Example Group 2 variables contribute to 88.95% of the inertia of the axis 1 of the PCA. The first axis ( F 1 {\displaystyle F_{1}} ) is almost coincident with C: the correlation between C and F 1 {\displaystyle F_{1}} is .976; The first axis of the MFA (on Table 1 data) shows the balance between the two groups of variables: the contribution of each group to the inertia of this axis is strictly equal to 50%. The second axis, meanwhile, depends only on group 1. This is natural since this group is two-dimensional while the second group, being one-dimensional, can be highly related to only one axis (here the first axis).
Specified complexity Criticism Specified_complexity > Criticism This basic flaw in his modeling renders all of Dembski's subsequent calculations and reasoning in No Free Lunch irrelevant because his basic model does not reflect reality. Since the basis of No Free Lunch relies on this flawed argument, the entire thesis of the book collapses.According to Martin Nowak, a Harvard professor of mathematics and evolutionary biology "We cannot calculate the probability that an eye came about. We don't have the information to make the calculation".Dembski's critics note that specified complexity, as originally defined by Leslie Orgel, is precisely what Darwinian evolution is supposed to create.
Supersymmetric theory Supersymmetry in quantum field theory Supersymmetric_theory > Applications > Supersymmetry in quantum field theory In quantum field theory, supersymmetry is motivated by solutions to several theoretical problems, for generally providing many desirable mathematical properties, and for ensuring sensible behavior at high energies. Supersymmetric quantum field theory is often much easier to analyze, as many more problems become mathematically tractable. When supersymmetry is imposed as a local symmetry, Einstein's theory of general relativity is included automatically, and the result is said to be a theory of supergravity.
Dew pond Summary Dew_pond A dew pond is an artificial pond usually sited on the top of a hill, intended for watering livestock. Dew ponds are used in areas where a natural supply of surface water may not be readily available. The name dew pond (sometimes cloud pond or mist pond) is first found in the Journal of the Royal Agricultural Society in 1865. Despite the name, their primary source of water is believed to be rainfall rather than dew or mist.
History of scientific method Aristotle History_of_scientific_method > Early methodology > Aristotle Aristotle has been called the founder of modern science by De Lacy O'Leary. His demonstration method is found in Posterior Analytics.
Polymeric foam Summary Polymeric_foam A polymeric foam is a special foam, in liquid or solidified form, formed from polymers. Examples include: Ethylene-vinyl acetate (EVA) foam, the copolymers of ethylene and vinyl acetate; also referred to as polyethylene-vinyl acetate (PEVA) Low-density polyethylene (LDPE) foam, first grade of polyethylene (PE) Nitrile rubber (NBR) foam, the copolymers of acrylonitrile (ACN) and butadiene Polychloroprene foam or Neoprene Polyimide foam Polypropylene (PP) foam, including expanded polypropylene (EPP) and polypropylene paper (PPP) Polystyrene (PS) foam, including expanded polystyrene (EPS), extruded polystyrene foam (XPS) and sometimes polystyrene paper (PSP) Styrofoam, including extruded polystyrene foam (XPS) and sometimes expanded polystyrene (EPS) Polyurethane (PU) foam LRPu low-resilience polyurethane Memory foam Sorbothane Polyurea foam Polyethylene foam, as used in PEF rod Polyvinyl chloride (PVC) foam Closed-cell PVC foamboard Silicone foam Microcellular foam
Fundamental theorem of Galois theory Properties of the correspondence Fundamental_theorem_of_Galois_theory > Properties of the correspondence The correspondence has the following useful properties. It is inclusion-reversing. The inclusion of subgroups H1 ⊆ H2 holds if and only if the inclusion of fields EH1 ⊇ EH2 holds. Degrees of extensions are related to orders of groups, in a manner consistent with the inclusion-reversing property.
Multicast DNS Protocol overview Multicast_DNS > Protocol overview When an mDNS client needs to resolve a hostname, it sends an IP multicast query message that asks the host having that name to identify itself. That target machine then multicasts a message that includes its IP address. All machines in that subnet can then use that information to update their mDNS caches. Any host can relinquish its claim to a name by sending a response packet with a time to live (TTL) equal to zero.
Spermatogenesis arrest Chemotherapy Spermatogenesis_arrest > Causes > Chemotherapy When using chemotherapy treatments, the possibility of azoospermia is dependent on the dose, duration, number and type of drugs used; the male's fertility status before the treatment occurred is also taken into consideration.
L'Hôpital's rule Differentiability of functions Bernoulli's_rule > Cases where theorem cannot be applied (Necessity of conditions) > Differentiability of functions For example, let f ( x ) = { sin ⁡ x , x ≠ 0 1 , x = 0 {\displaystyle f(x)={\begin{cases}\sin x,&x\neq 0\\1,&x=0\end{cases}}} , g ( x ) = x {\displaystyle g(x)=x} , and c = 0 {\displaystyle c=0} . In this case, f ( x ) {\displaystyle f(x)} is not differentiable at c {\displaystyle c} . However, since f ( x ) {\displaystyle f(x)} is differentiable everywhere except c {\displaystyle c} , then lim x → c f ′ ( x ) {\displaystyle \lim _{x\to c}f'(x)} still exists. Thus, since lim x → c f ( x ) g ( x ) = 0 0 {\displaystyle \lim _{x\to c}{\frac {f(x)}{g(x)}}={\frac {0}{0}}} and lim x → c f ′ ( x ) g ′ ( x ) {\displaystyle \lim _{x\to c}{\frac {f'(x)}{g'(x)}}} exists, L'Hôpital's rule still holds.
Functional composition Properties Functional_composition > Properties The composition of one-to-one (injective) functions is always one-to-one. Similarly, the composition of onto (surjective) functions is always onto. It follows that the composition of two bijections is also a bijection. The inverse function of a composition (assumed invertible) has the property that (f ∘ g)−1 = g−1∘ f−1.Derivatives of compositions involving differentiable functions can be found using the chain rule. Higher derivatives of such functions are given by Faà di Bruno's formula.
Ozone Depleting Substances Cortical cataracts Ozone_depleting > Increased UV > Biological effects > Cortical cataracts Epidemiological studies suggest an association between ocular cortical cataracts and UV-B exposure, using crude approximations of exposure and various cataract assessment techniques. A detailed assessment of ocular exposure to UV-B was carried out in a study on Chesapeake Bay Watermen, where increases in average annual ocular exposure were associated with increasing risk of cortical opacity. In this highly exposed group of predominantly white males, the evidence linking cortical opacities to sunlight exposure was the strongest to date. Based on these results, ozone depletion is predicted to cause hundreds of thousands of additional cataracts by 2050.
Computer Othello Search techniques Computer_Othello > Search techniques Computer Othello programs search for any possible legal moves using a game tree. In theory, they examine all positions / nodes, where each move by one player is called a "ply". This search continues until a certain maximum search depth or the program determines that a final "leaf" position has been reached. A naive implementation of this approach, known as Minimax or Negamax, can only search to a small depth in a practical amount of time, so various methods have been devised to greatly increase the speed of the search for good moves.
Glossary of set theory S Glossary_of_set_theory > S A Skolem function is a function whose value is something with a given property if anything with that property exists 4. The Skolem hull of a model is its closure under Skolem functions small A small large cardinal axiom is a large cardinal axiom consistent with the axiom V=L SOCA Semi open coloring axiom Solovay 1. Robert M. Solovay 2.
Net force The Concept of Total Force Net_force > The Concept of Total Force This is because, besides the net force, the 'torque' or rotational effect associated with these forces also matters. The net force must be applied at the right point, and with the right associated torque, to replicate the effect of the original forces. When the net force and the appropriate torque are applied at a single point, they together constitute what is known as the resultant force. This resultant force-and-torque combination will have the same effect on the body as all the original forces and their associated torques.
Non-intrusive stress measurement system Method Non-intrusive_stress_measurement_system > Method A set of sensors is used to measure the arrival times of rotating blades. These arrival times, in comparison to a baseline, are used to determine blade deflections. The blade deflections over a number of revolutions and/or across a number of sensors can be used to determine vibratory characteristics. This information, in conjunction with a finite element model (FEM), can then be used to determine the dynamic stresses in a rotating part.
Plant genetics DNA Plant_genetics > DNA Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of blueprints or a recipe, or a code, since it contains the instructions needed to construct other components of cells, such as proteins and RNA molecules. The DNA segments that carry this genetic information are called genes, and their location within the genome are referred to as genetic loci, but other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information. Geneticists, including plant geneticists, use this sequence of DNA to their advantage to better find and understand the role of different genes within a given genome. Through research and plant breeding, manipulation of different plant genes and loci encoded by the DNA sequence of the plant chromosomes by various methods can be done to produce different or desired genotypes that result in different or desired phenotypes.
Cantor-Bendixson theorem Summary Perfect_subset_property However, in Solovay's model, which satisfies all axioms of ZF but not the axiom of choice, every set of reals has the perfect set property, so the use of the axiom of choice is necessary. Every analytic set has the perfect set property. It follows from the existence of sufficiently large cardinals that every projective set has the perfect set property.
List of proposed quantum registers Summary List_of_proposed_quantum_registers 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. Superconducting quantum computing (qubit implemented by the state of nonlinear resonant superconducting circuits containing Josephson junctions) Trapped ion quantum computer (qubit implemented by the internal state of trapped ions) Neutral atoms in optical lattices (qubit implemented by internal states of neutral atoms trapped in an optical lattice) Quantum dot computer, spin-based (e.g. the Loss-DiVincenzo quantum computer) (qubit given by the spin states of trapped electrons) Quantum dot computer, spatial-based (qubit given by electron position in double quantum dot) Quantum computing using engineered quantum wells, which could in principle enable the construction of a quantum computer that operates at room temperature Coupled quantum wire (qubit implemented by a pair of quantum wires coupled by a quantum point contact) Nuclear magnetic resonance quantum computer (NMRQC) implemented with the nuclear magnetic resonance of molecules in solution, where qubits are provided by nuclear spins within the dissolved molecule and probed with radio waves Solid-state NMR Kane quantum computer (qubit realized by the nuclear spin state of phosphorus donors in silicon) Vibrational quantum computer (qubits realized by vibrational superpositions in cold molecules) Electrons-on-helium quantum computer (qubit is the electron spin) Cavity quantum electrodynamics (CQED) (qubit provided by the internal state of trapped atoms coupled to high-finesse cavities) Molecular magnet (qubit given by spin states) Fullerene-based ESR quantum computer (qubit based on the electronic spin of atoms or molecules encased in fullerenes) Nonlinear optical quantum computer (qubits realized by processing states of different modes of light through both linear and nonlinear elements) Linear optical quantum computer (LOQC) (qubits realized by processing states of different modes of light through linear elements e.g. mirrors, beam splitters and phase shifters). Quantum microprocessor based on laser photonics at room temperature made possible. Diamond-based quantum computer (qubit realized by the electronic or nuclear spin of nitrogen-vacancy centers in diamond) Bose-Einstein condensate-based quantum computer Transistor-based quantum computer (string quantum computers with entrainment of positive holes using an electrostatic trap) Rare-earth-metal-ion-doped inorganic crystal based quantum computer (qubit realized by the internal electronic state of dopants in optical fibers) Metallic-like carbon nanospheres-based quantum computer == References ==
Gearless Wind turbine The hub Wind_turbine_design > Blades > The hub In simple designs, the blades are directly bolted to the hub and are unable to pitch, which leads to aerodynamic stall above certain windspeeds. In more sophisticated designs, they are bolted to the pitch bearing, which adjusts their angle of attack with the help of a pitch system according to the wind speed. Pitch control is performed by hydraulic or electric systems (battery or ultracapacitor). The pitch bearing is bolted to the hub. The hub is fixed to the rotor shaft which drives the generator directly or through a gearbox.
NMR Chemical Shift Re-referencing General References Nuclear_magnetic_resonance_chemical_shift_re-referencing > General References doi:10.1023/B:JNMR.0000015420.44364.06. PMID 14872126. S2CID 14483199.
Energetically modified cement VBM Kinetics Energetically_modified_cement > EMC Activation > Vibratory Ball Mills (VBMs) > VBM Kinetics In simple terms, the compressive force F {\displaystyle F} acting between two identical colliding balls in a VBM can be expressed: F = v 6 / 5 {\displaystyle F=\leftv^{6/5}} where, k = 1 − v 2 π E {\displaystyle k={\frac {1-v^{2}}{\pi E}}} where, m {\displaystyle m} is the mass of both balls, r {\displaystyle r} the radius, v {\displaystyle v} the absolute velocity of impact and E {\displaystyle E} the Young's modulus of the balls' material.As can be seen, an increase in velocity of impact increases F {\displaystyle F} . The size and mass of the grinding media also contribute. F {\displaystyle F} 's denominator term k {\displaystyle k} incorporates E {\displaystyle E} meaning that the nature of the material used for the grinding media is an important factor ( k {\displaystyle k} is ultimately squared in F {\displaystyle F} , so its negative value is of no consequence). More fundamentally, due to the rapid vibration a high acceleration is imparted to the grinding media, whereupon the continuous, short, sharp impacts on the load result in rapid particle-size reduction.
Tactile imaging Processing and presentation Shear-wave_elasticity_imaging > How it works > Processing and presentation Once the response has been observed, the stiffness can be calculated from it. Most elastography techniques find the stiffness of tissue based on one of two main principles: For a given applied force (stress), stiffer tissue deforms (strains) less than does softer tissue. Mechanical waves (specifically shear waves) travel faster through stiffer tissue than through softer tissue.Some techniques will simply display the distortion and/or response, or the wave speed to the operator, while others will compute the stiffness (specifically the Young's modulus or similar shear modulus) and display that instead. Some techniques present results quantitatively, while others only present qualitative (relative) results.
BTB E2E Description BTB_E2E > Description A driving cab with simple controls, including air brakes, was fitted to one end of the superstructure. A two speed gearbox, switchable when the locomotive was stationary, was fitted. The lower gear allowed a maximum speed of 18 km/h (11 mph) on a slope of 25 ‰ drawing a load of 100 tonnes (98 long tons; 110 short tons). The higher gear was designed for the locomotive to travel at up to 36 km/h (22 mph).The gearbox proved to be problematic and was revised by SLM in 1900. Later, the gearing was changed to allow for a higher speed of 50 km/h (31 mph).
Pituitary adenylate cyclase-activating peptide Interactions Pituitary_adenylyl_cyclase-activating_peptide > Interactions Pituitary adenylate cyclase-activating peptide has been shown to interact with secretin receptor.
Gauge boson Summary Gauge_bosons In particle physics, a gauge boson is a bosonic elementary particle that acts as the force carrier for elementary fermions. Elementary particles whose interactions are described by a gauge theory interact with each other by the exchange of gauge bosons, usually as virtual particles. Photons, W and Z bosons, and gluons are gauge bosons. All known gauge bosons have a spin of 1; for comparison, the Higgs boson has spin zero and the hypothetical graviton has a spin of 2. Therefore, all known gauge bosons are vector bosons. Gauge bosons are different from the other kinds of bosons: first, fundamental scalar bosons (the Higgs boson); second, mesons, which are composite bosons, made of quarks; third, larger composite, non-force-carrying bosons, such as certain atoms.
Membrane curvature Cytoskeleton Membrane_curvature > Induced by proteins > Cytoskeleton The overall shape of a cell is mostly determined by its cytoskeletal structure. This shape will vary widely depending on the location and function of the cell. The cell membrane must be able to curve around and fit the shape determined by these functions.
Aristotle's wheel paradox Second solution Aristotle's_wheel_paradox > Analysis and solutions > Second solution This solution considers the transition from the starting to ending positions. Let Pb be a point on the bigger circle and Ps be a point on the smaller circle, both on the same radius. For convenience, assume they are both directly below the center, analogous to both hands of a clock pointing towards six. Both Pb and Ps travel in a cycloid path as they roll together one revolution.While each travels 2πR horizontally from start to end, Ps's cycloid path is shorter and more efficient than Pb's.
Manin matrices Capelli matrix as Manin matrix, and center of U(gln) Manin_matrix > Examples and applications > Capelli matrix as Manin matrix, and center of U(gln) {\displaystyle E_{ij}=x_{i}{\frac {\partial }{\partial x_{j}}};~~~~~E_{ij}=\sum _{a=1}^{n}x_{ia}{\frac {\partial }{\partial x_{ja}}};~~~~E_{ij}=\psi _{i}{\frac {\partial }{\partial \psi _{j}}}.} Here ψ are Grassmann variables. Observation.
False Alarm Rate Statistical background Type_I_error_rate > Definition > Statistical background The alternative hypothesis corresponds to the position against the defendant. Specifically, the null hypothesis also involves the absence of a difference or the absence of an association. Thus, the null hypothesis can never be that there is a difference or an association.
Two-dimensional correlation analysis Presence of 2D spectra Two-dimensional_correlation_analysis > Presence of 2D spectra As the peaks at (x,y) in the 2D synchronous spectrum are a measure for the correlation between the intensity changes at x and y in the original data, these main diagonal peaks are also called autopeaks and the main diagonal signal is referred to as autocorrelation signal. The off-diagonal cross-peaks can be either positive or negative.
Smart objects Summary Smart_object A smart object is an object that enhances the interaction with not only people but also with other smart objects. Also known as smart connected products or smart connected things (SCoT), they are products, assets and other things embedded with processors, sensors, software and connectivity that allow data to be exchanged between the product and its environment, manufacturer, operator/user, and other products and systems. Connectivity also enables some capabilities of the product to exist outside the physical device, in what is known as the product cloud. The data collected from these products can be then analyzed to inform decision-making, enable operational efficiencies and continuously improve the performance of the product.
Hypothyroidism Summary Secondary_hypothyroidism Hypothyroidism (also called underactive thyroid, low thyroid or hypothyreosis) is a disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone. It can cause a number of symptoms, such as poor ability to tolerate cold, a feeling of tiredness, constipation, slow heart rate, depression, and weight gain. Occasionally there may be swelling of the front part of the neck due to goitre. Untreated cases of hypothyroidism during pregnancy can lead to delays in growth and intellectual development in the baby or congenital iodine deficiency syndrome.Worldwide, too little iodine in the diet is the most common cause of hypothyroidism.
Turing oracle Oracles Turing_oracle > Oracles An instance of the problem is an arbitrary natural number (or string). The solution to the instance is "YES" if the number (string) is in the set, and "NO" otherwise. A function problem is represented by a function f from natural numbers (or strings) to natural numbers (or strings). An instance of the problem is an input x for f. The solution is the value f(x).An oracle machine can perform all of the usual operations of a Turing machine, and can also query the oracle to obtain a solution to any instance of the computational problem for that oracle. For example, if the problem is a decision problem for a set A of natural numbers, the oracle machine supplies the oracle with a natural number, and the oracle responds with "yes" or "no" stating whether that number is an element of A.
Video game controller Others Video_game_controllers > Variants > Others Physically it resembles a gamepad, but its left and right halves twist relative to each other, making it a variation of the paddle controller. Optical motion tracking systems such as TrackIR and FreeTrack use a video camera to track an infrared illuminated or emissive headpiece. Small head movements are tracked and then translated into much larger virtual in-game movements, allowing hands-free view control and improved immersiveness.
Anaerobic respiration Ecological importance Anaerobic_respiration > Ecological importance An example of the ecological importance of anaerobic respiration is the use of nitrate as a terminal electron acceptor, or dissimilatory denitrification, which is the main route by which fixed nitrogen is returned to the atmosphere as molecular nitrogen gas. The denitrification process is also very important in host-microbe interactions. Similar to mitochondria in oxygen-respiring microorganisms, some single-cellular anaerobic ciliates use denitrifying endosymbionts to gain energy.
Hardware overlay Summary Hardware_overlay In computing, hardware overlay, a type of video overlay, provides a method of rendering an image to a display screen with a dedicated memory buffer inside computer video hardware. The technique aims to improve the display of a fast-moving video image — such as a computer game, a DVD, or the signal from a TV card. Most video cards manufactured since about 1998 and most media players support hardware overlay.The overlay is a dedicated buffer into which one app can render (typically video), without incurring the significant performance cost of checking for clipping and overlapping rendering by other apps. The framebuffer has hardware support for importing and rendering the buffer contents without going through the GPU.
Statistical power Bayesian power Statistical_power > Extension > Bayesian power In the frequentist setting, parameters are assumed to have a specific value which is unlikely to be true. This issue can be addressed by assuming the parameter has a distribution. The resulting power is sometimes referred to as Bayesian power which is commonly used in clinical trial design.
Normal stress Definition Longitudinal_stress > Definition Stress is defined as the force across a small boundary per unit area of that boundary, for all orientations of the boundary. Derived from a fundamental physical quantity (force) and a purely geometrical quantity (area), stress is also a fundamental quantity, like velocity, torque or energy, that can be quantified and analyzed without explicit consideration of the nature of the material or of its physical causes. Following the basic premises of continuum mechanics, stress is a macroscopic concept. Namely, the particles considered in its definition and analysis should be just small enough to be treated as homogeneous in composition and state, but still large enough to ignore quantum effects and the detailed motions of molecules.
Screw Mechanical classifications Screw > Mechanical classifications Ultimate tensile strength is the tensile stress at which the bolt fails. Tensile yield strength is the stress at which the bolt will yield in tension across the entire section of the bolt and receive a permanent set (an elongation from which it will not recover when the force is removed) of 0.2% offset strain. Proof strength is the usable strength of the fastener.
Casein kinase 1 Interphase, mitosis and DNA repair Casein_kinase_1 > Roles > Interphase, mitosis and DNA repair CKIδ activity is implicated in mitosis and in response to DNA damage. During interphase, CKIδ associates with the Golgi Apparatus and appears to regulate the budding of clathrin coated vesicles from the TGN; it also appears to associate with tubulin. While undamaged mitotic cells shows no CKIδ association with tubulin, the kinase was recruited during mitosis in cells with DNA damage, indicative of a role for CKIδ in arranging the microtubule network during mitosis. The mechanisms for these biochemical interactions remain unknown.
Standards for Reporting Enzymology Data Applications Standards_for_Reporting_Enzymology_Data > Applications The database service is recommended in the authors' instructions of more than 10 biochemistry journals, including Nature, The Journal of Biological Chemistry, eLife, and PLoS. It has been referred as a standard tool for the validation and storage of enzyme kinetics data in multifold publications A recent study examining eleven publications, including Supporting Information, from two leading journals revealed that at least one omission was found in every one of these papers. The authors concluded that using STRENDA DB in the current version would ensure that about 80% auf the relevant information would be made available.Data Management STRENDA DB is considered a tool for research data management by the research community (e.g. EU project CARBAFIN).
Glossary of genetics (0–L) C Glossary_of_gene_expression_terms > C A sequence of DNA in which a cytosine nucleotide is immediately followed by a guanine nucleotide on the same strand in the 5'-to-3' direction; the "p" in CpG refers simply to the intervening phosphate group linking the two consecutive nucleotides. CpG island Also CG island and C-G island. A region of a genome in which CpG sites occur repetitively or with high frequency.
Direct policy search Introduction Inverse_reinforcement_learning > Introduction Due to its generality, reinforcement learning is studied in many disciplines, such as game theory, control theory, operations research, information theory, simulation-based optimization, multi-agent systems, swarm intelligence, and statistics. In the operations research and control literature, reinforcement learning is called approximate dynamic programming, or neuro-dynamic programming. The problems of interest in reinforcement learning have also been studied in the theory of optimal control, which is concerned mostly with the existence and characterization of optimal solutions, and algorithms for their exact computation, and less with learning or approximation, particularly in the absence of a mathematical model of the environment. In economics and game theory, reinforcement learning may be used to explain how equilibrium may arise under bounded rationality.
Antihypertensive agent Patient factors Antihypertensive_drug > Choice of initial medication > Patient factors Age and multi-morbidity can affect the choice of medication, the target blood pressure and even whether to treat or not. Anxiety may be improved with the use of beta blockers. Asthmatics have been reported to have worsening symptoms when using beta blockers.
Google DeepMind Deep reinforcement learning Google_DeepMind > Products and technologies > Deep reinforcement learning As opposed to other AIs, such as IBM's Deep Blue or Watson, which were developed for a pre-defined purpose and only function within that scope, DeepMind claims that its system is not pre-programmed: it learns from experience, using only raw pixels as data input. Technically it uses deep learning on a convolutional neural network, with a novel form of Q-learning, a form of model-free reinforcement learning. They test the system on video games, notably early arcade games, such as Space Invaders or Breakout. Without altering the code, the AI begins to understand how to play the game, and after some time plays, for a few games (most notably Breakout), a more efficient game than any human ever could.In 2013, DeepMind published research on an AI system that could surpass human abilities in games such as Pong, Breakout and Enduro, while surpassing state of the art performance on Seaquest, Beamrider, and Q*bert. This work reportedly led to the company's acquisition by Google. DeepMind's AI had been applied to video games made in the 1970s and 1980s; work was ongoing for more complex 3D games such as Quake, which first appeared in the 1990s.In 2020, DeepMind published Agent57, an AI Agent which surpasses human level performance on all 57 games of the Atari2600 suite.
Adaptive immunity in jawless vertebrates Evolution Adaptive_immunity_in_jawless_vertebrates > Evolution However, MHCs or MHC-like molecules that could present processed antigens have not been found in lampreys, and some VLRAs expressed in yeast were able to directly bind to antigens. The antigen binding of VLRCs has not been studied. However, the VLRC gene is close in proximity and sequence to the VLRA gene and the two are often co-expressed in LLCs, suggesting that both are TCR-like receptors.
Longest path problem Special classes of graphs Longest_path_problem > Special classes of graphs A simple model of a directed acyclic graph is the Price model, developed by Derek J. de Solla Price to represent citation networks. This is simple enough to allow for analytic results to be found for some properties. For instance, the length of the longest path, from the n-th node added to the network to the first node in the network, scales as ln ⁡ ( n ) {\displaystyle \ln(n)} .
Floppy-disk controller Overview Floppy-disk_controller > Overview Some controllers require this encoding to be performed externally, but most designs provide standard encodings like FM and MFM. The controller also provides a number of other services to control the drive mechanism itself. These typically include the movement of the drive head to center over the separate tracks on the disk, tracking the location of the head and returning it to zero, and sometimes functionally to format a disk based on simple inputs like the number of tracks, sectors per track and number of bytes per sector.
Web Accessibility Initiative Authoring Tool Accessibility Guidelines (ATAG) Web_Accessibility_Initiative > Guidelines and technical reports > Authoring Tool Accessibility Guidelines (ATAG) Developed by the Authoring Tool Accessibility Guidelines Working Group, the ATAG 2.0 became a W3C Recommendation on 24 September 2015. ATAG is a set of guidelines for developers of any kind of authoring tool for Web content: simple HTML editors, tools that export content for use on the Web (for example, word processors that can save as HTML), tools that produce multimedia, content management systems, learning management systems, social media, etc.. The goal is for developers to create tools that: are accessible to authors regardless of disability; produce accessible content by default; support and encourage authors to create accessible content.Implementing ATAG 2.0 is a companion document that provides guidance on understanding and implementing ATAG 2.0. It gives an explanation of the intent of each success criterion, examples of the success criterion, and additional resources. Implementing ATAG 2.0 recommendations can reduce the costs for accessibility because authors are given the tools they need to create accessible content. List of authoring tools looking to implement ATAG 2.0: CKEditor DrupalAuthoring Tool Accessibility Guidelines 1.0 was published in 2000 by the Authoring Tool Accessibility Guidelines Working Group.
Critical dimension Upper critical dimension in field theory Critical_dimension > Upper critical dimension in field theory Determining the upper critical dimension of a field theory is a matter of linear algebra. It is worthwhile to formalize the procedure because it yields the lowest-order approximation for scaling and essential input for the renormalization group. It also reveals conditions to have a critical model in the first place.
Vieta jumping Constant descent Vieta jumping Vieta_jumping > Constant descent Vieta jumping One root to this quadratic is a, so by Vieta's formulas the other root may be written as follows: x2 = kb − a = b2 + 1/a. The first equation shows that x2 is an integer and the second that it is positive.
Reacting games Historical simulation games Reacting_games > Relationship to other games and simulations > Historical simulation games Historical simulation games are designed to model historical events. Both tabletop and electronic forms can be used in classes with the intent to challenge students to work through difficult scenarios and explore possible alternate historical outcomes. Reacting games may contain components of historical simulation games including random events and alternate historical outcomes, however, they are more typically focused around the clash of ideas and people than the direct modeling of military or historical events.
Chromosomal crossover Consequences Chromosomal_crossover > Consequences This leads to the notion of "genetic distance", which is a measure of recombination frequency averaged over a (suitably large) sample of pedigrees. Loosely speaking, one may say that this is because recombination is greatly influenced by the proximity of one gene to another. If two genes are located close together on a chromosome, the likelihood that a recombination event will separate these two genes is less than if they were farther apart.
Enzyme reaction rate Ternary-complex mechanisms Enzyme_kinetics > Multi-substrate reactions > Ternary-complex mechanisms In these enzymes, both substrates bind to the enzyme at the same time to produce an EAB ternary complex. The order of binding can either be random (in a random mechanism) or substrates have to bind in a particular sequence (in an ordered mechanism). When a set of v by curves (fixed A, varying B) from an enzyme with a ternary-complex mechanism are plotted in a Lineweaver–Burk plot, the set of lines produced will intersect. Enzymes with ternary-complex mechanisms include glutathione S-transferase, dihydrofolate reductase and DNA polymerase. The following links show short animations of the ternary-complex mechanisms of the enzymes dihydrofolate reductase and DNA polymerase.
Signal flow Broadcast performance signal flow example Signal_flow > Broadcast performance signal flow example Over amplifying the signal can cause the preamplifier to distort, which can under certain circumstances produce a desirable sound. After the line trim, the signal is processed by the mixing board's EQ, filter, compressor, limiter, de-esser, delay, reverb, and any other signal processing features the mixing board has available and that the mix engineer chooses to use. The processed signal is then sent to the mix bus, where it is combined with all the other signals coming from the stage.
State space representation Summary Modern_control_theory The state of the system can be represented as a vector, the state vector, within state space. If the dynamical system is linear, time-invariant, and finite-dimensional, then the differential and algebraic equations may be written in matrix form. The state-space method is characterized by significant algebraization of general system theory, which makes it possible to use Kronecker vector-matrix structures.
Small nucleolar RNA SNORD45 Summary Small_nucleolar_RNA_SNORD45 In molecular biology, snoRNA U45 (also known as SNORD45) is a non-coding RNA (ncRNA) molecule which functions in the modification of other small nuclear RNAs (snRNAs). This type of modifying RNA is usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
Posner cueing task Overt and covert attention Posner_cueing_task > Method > Overt and covert attention In some studies using this paradigm, eye movements are tracked with either video-based eye tracking systems or electric potentials recorded from electrodes positioned around the eye, a process called electrooculography (EOG). This method is used to differentiate overt and covert attention. Overt attention involves directed eye movements, known as saccades, to consciously focus the eye on a target stimulus. Covert attention involves mental focus or attention to an object without significant eye movement, and is the predominant area of interest when using the Posner cueing task for research.
Necrotising fasciitis Bacteria Necrotizing_fasciitis > Cause > Bacteria Types of soft-tissue necrotizing infection can be divided into four classes according to the types of bacteria infecting the soft tissue. This classification system was first described by Giuliano and his colleagues in 1977.Type I infection: This is the most common type of infection, and accounts for 70 to 80% of cases. It is caused by a mixture of bacterial types, usually in abdominal or groin areas. This type of infection is usually caused by various species of Gram-positive cocci, (Staphylococcus aureus, Streptococcus pyogenes, and enterococci), Gram-negative rods, (Escherichia coli, Pseudomonas aeruginosa), and anaerobes, (Bacteroides and Clostridium species).
Torque tester Transducer Torque_tester > Components > Transducer A torque transducer, similar to a load cell, is an electronic device used to convert torque into an electrical signal. This conversion is indirect and happens in two stages. Through a mechanical arrangement, the torque being sensed deforms a strain gauge. The strain gauge converts the deformation (strain) to electrical signals.
Reverse Engineering Gene networks Reverse_engineer > Common uses > Gene networks Reverse engineering concepts have been applied to biology as well, specifically to the task of understanding the structure and function of gene regulatory networks. They regulate almost every aspect of biological behavior and allow cells to carry out physiological processes and responses to perturbations. Understanding the structure and the dynamic behavior of gene networks is therefore one of the paramount challenges of systems biology, with immediate practical repercussions in several applications that are beyond basic research.
Doppler navigation History Aberration_redshift > History Doppler first proposed this effect in 1842 in his treatise "Über das farbige Licht der Doppelsterne und einiger anderer Gestirne des Himmels" (On the coloured light of the binary stars and some other stars of the heavens). The hypothesis was tested for sound waves by Buys Ballot in 1845. He confirmed that the sound's pitch was higher than the emitted frequency when the sound source approached him, and lower than the emitted frequency when the sound source receded from him. Hippolyte Fizeau discovered independently the same phenomenon on electromagnetic waves in 1848 (in France, the effect is sometimes called "effet Doppler-Fizeau" but that name was not adopted by the rest of the world as Fizeau's discovery was six years after Doppler's proposal). In Britain, John Scott Russell made an experimental study of the Doppler effect (1848).

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