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COVID-19 pandemic and animals Cases COVID-19_pandemic_and_animals > Cases According to the US Centers for Disease Control and Prevention, the risk of transmission from animals to humans and vice versa is considerably low but further studies are yet to be conducted. Mice were initially unsusceptible but researchers showed that a type of mutation (called aromatic substitution in position 501 or position 498 but not both) in the SARS-CoV-2 virus spike protein can mouse-adapt the novel Coronavirus. Some animals which were only thought to have been susceptible at low levels were later found to have experienced higher levels of infection than previously realized, either due to viral mutations or improved surveillance technology. Dogs, for instance, showcased low levels of infection or transmission early in the pandemic, but were later found to have experienced potentially elevated levels of asymptomatic infections.Animal deaths due to the disease are confirmed to have occurred on numerous occasions, with some species, such as mink, being particularly vulnerable and experiencing high mortality rates.
Navigation chart Publication Navigation_chart > Publication Individual hydrographic offices produce national chart series and international chart series. Coordinated by the International Hydrographic Organization, the international chart series is a worldwide system of charts ("INT" chart series), which is being developed with the goal of unifying as many chart systems as possible. There are also commercially published charts, some of which may carry additional information of particular interest, e.g. for yacht skippers.
Spermatogenesis Spermatidogenesis Secondary_spermatocyte > Stages > Spermatidogenesis Spermatidogenesis is the creation of spermatids from secondary spermatocytes. Secondary spermatocytes produced earlier rapidly enter meiosis II and divide to produce haploid spermatids. The brevity of this stage means that secondary spermatocytes are rarely seen in histological studies.
Strain theory (sociology) Role strain theory Strain_theory_(sociology) > Derived theories > Role strain theory In order for the society to continue existing, these obligations must be fulfilled at the volition of the individuals in it, which the theory states is what most people are inclined to do. Due to the fact that there is no force involved in maintaining these role relationships, there will be individuals who can not, or will not, conform to these societal expectations. In addition, the individuals within the society are not bound to one role relationship.
Continuity correction Binomial Continuity_correction > Examples > Binomial If a random variable X has a binomial distribution with parameters n and p, i.e., X is distributed as the number of "successes" in n independent Bernoulli trials with probability p of success on each trial, then P ( X ≤ x ) = P ( X < x + 1 ) {\displaystyle P(X\leq x)=P(X
Biological Magnetic Resonance Data Bank NMR restraints grid Biological_Magnetic_Resonance_Data_Bank > Content > NMR restraints grid The NMR restraints grid contains NMR restraints data from over 2500 proteins and nucleic acids collected from PDB depositions. The grid is constructed as four subsets of data: The original NMR data: This subset contains data as found in depositions from the PDB. The data are in various different file formats and contain information about interatomic distances, dihedral angles and RDC restraints. Parsed restraints data: Most of the entries in the original data subset have been parsed into the NMR-star file format facilitating its access and use.
Cross-correlation Cross-correlation of stochastic processes Cross-correlation_coefficient > Cross-correlation of stochastic processes In time series analysis and statistics, the cross-correlation of a pair of random process is the correlation between values of the processes at different times, as a function of the two times. Let ( X t , Y t ) {\displaystyle (X_{t},Y_{t})} be a pair of random processes, and t {\displaystyle t} be any point in time ( t {\displaystyle t} may be an integer for a discrete-time process or a real number for a continuous-time process). Then X t {\displaystyle X_{t}} is the value (or realization) produced by a given run of the process at time t {\displaystyle t} .
Specific heat capacity Calculation from first principles Specific_heat_capacity > Thermodynamic derivation > Calculation from first principles The path integral Monte Carlo method is a numerical approach for determining the values of heat capacity, based on quantum dynamical principles. However, good approximations can be made for gases in many states using simpler methods outlined below. For many solids composed of relatively heavy atoms (atomic number > iron), at non-cryogenic temperatures, the heat capacity at room temperature approaches 3R = 24.94 joules per kelvin per mole of atoms (Dulong–Petit law, R is the gas constant). Low temperature approximations for both gases and solids at temperatures less than their characteristic Einstein temperatures or Debye temperatures can be made by the methods of Einstein and Debye discussed below. However, attention should be made for the consistency of such ab-initio considerations when used along with an equation of state for the considered material.
Data model (GIS) Raster data model Data_model_(GIS) > Raster data model The raster logical model represents a field using a tessellation of geographic space into a regularly spaced two-dimensional array of locations (each called a cell), with a single attribute value for each cell (or more than one value in a multi-band raster). Typically, each cell either represents a single central point sample (in which the measurement model for the entire raster is called a lattice) or it represents a summary (usually the mean) of the field variable over the square area (in which the model is called a grid). : 86 The general data model is essentially the same as that used for images and other raster graphics, with the addition of capabilities for the geographic context. A small example follows: To represent a raster grid in a computer file, it must be serialized into a single (one-dimensional) list of values.
Orbital momentum vector Analogy to linear momentum Conservation_of_Angular_Momentum > Analogy to linear momentum Energy, the ability to do work, can be stored in matter by setting it in motion—a combination of its inertia and its displacement. Inertia is measured by its mass, and displacement by its velocity. Their product, is the matter's momentum.
Abstraction (computer science) Considerations Data_abstraction > Considerations As a consequence, automatic methods for deriving information on the behavior of computer programs either have to drop termination (on some occasions, they may fail, crash or never yield out a result), soundness (they may provide false information), or precision (they may answer "I don't know" to some questions). Abstraction is the core concept of abstract interpretation. Model checking generally takes place on abstract versions of the studied systems.
Glossary of environmental science G Glossary_of_environmental_science > G greenhouse effect - the process in which the emission of infrared radiation by the atmosphere warms a planet's surface. greenhouse gas - components of the atmosphere that contribute to the greenhouse effect. green manure - a type of cover crop grown primarily to add nutrients and organic matter to the soil.
Phenomenon-based learning Constructivism Phenomenon-based_learning > Features > Constructivism PhBL is a constructivist form of learning, in which learners are seen as active knowledge builders and information is seen as being constructed as a result of problem-solving. Information and skills are constructed out of ‘little pieces’ into a whole relevant to the situation at the time. When phenomenon based learning occurs in a collaborative setting (the learners work in teams, for example), it supports the socio-constructivist and sociocultural learning theories, in which information is not seen only as an internal element of an individual; instead, information is seen as being formed in a social context. Central issues in the sociocultural learning theories include cultural artifacts (e.g. systems of symbols such as language, mathematical calculation rules and different kinds of thinking tools) – not every learner needs to reinvent the wheel, they can use the information and tools transmitted by cultures.
Metastatic tumor Summary Metastatic_cancer This process is known (respectively) as lymphatic or hematogenous spread. After the tumor cells come to rest at another site, they re-penetrate the vessel or walls and continue to multiply, eventually forming another clinically detectable tumor.
Cellular life Prokaryotic cells Biological_cell > Cell types > Prokaryotic cells Though not forming a nucleus, the DNA is condensed in a nucleoid. Plasmids encode additional genes, such as antibiotic resistance genes. On the outside, flagella and pili project from the cell's surface. These are structures (not present in all prokaryotes) made of proteins that facilitate movement and communication between cells.
Atomic theory of matter Discovery of subatomic particles Nuclear_atom > History > Discovery of subatomic particles He concluded that these rays, rather than being a form of light, were composed of very light negatively charged particles. Thomson called these "corpuscles", but other scientists called them electrons, following an 1894 suggestion by George Johnstone Stoney for naming the basic unit of electrical charge. He measured the mass-to-charge ratio and discovered it was 1800 times smaller than that of hydrogen, the smallest atom.
Momentum curtain Summary Momentum_curtain Discovered by British engineer Christopher Cockerell, the momentum curtain is a unique and efficient way to reduce friction between a vehicle and its surface of travel, be it water or land, by levitating the vehicle above this surface via a cushion of air. It is this principle of levitation upon which a hovercraft is based, and Christopher Cockerell set about applying his momentum curtain theory to hovercraft to increase their abilities in overcoming friction in travel.Levitating a vehicle above the ground/water to reduce its drag was not a new concept. John Thornycroft, in 1877, discovered that trapping air beneath a ship's hull, or pumping air beneath it with bellows, decreased the effects of friction upon the hull thereby increasing the ship's top attainable speeds. However, technology at the time was insufficient for Thornycroft's ideas to be developed further.
Physical organic chemistry Quantum chemistry Physical_organic_chemistry > Quantum chemistry The energy associated with a particular wavefunction, perhaps the most important information contained in a wavefunction, can be extracted by solving the Schrödinger equation (above, Ψ is the wavefunction, E is the energy, and Ĥ is the Hamiltonian operator) in which an appropriate Hamiltonian operator is applied. In the various forms of the Schrödinger equation, the overall size of a particle's probability distribution increases with decreasing particle mass. For this reason, nuclei are of negligible size in relation to much lighter electrons and are treated as point charges in practical applications of quantum chemistry.
Natural background radiation Cosmic radiation Natural_radiation > Natural background radiation > Cosmic radiation The Earth and all living things on it are constantly bombarded by radiation from outer space. This radiation primarily consists of positively charged ions from protons to iron and larger nuclei derived from outside the Solar System. This radiation interacts with atoms in the atmosphere to create an air shower of secondary radiation, including X-rays, muons, protons, alpha particles, pions, electrons, and neutrons. The immediate dose from cosmic radiation is largely from muons, neutrons, and electrons, and this dose varies in different parts of the world based largely on the geomagnetic field and altitude.
Fission product Decay Fission_products > Decay Many of the fission products decay through very short-lived isotopes to form stable isotopes, but a considerable number of the radioisotopes have half-lives longer than a day. The radioactivity in the fission product mixture is initially mostly caused by short lived isotopes such as 131I and 140Ba; after about four months 141Ce, 95Zr/95Nb and 89Sr take the largest share, while after about two or three years the largest share is taken by 144Ce/144Pr, 106Ru/106Rh and 147Pm. Later 90Sr and 137Cs are the main radioisotopes, being succeeded by 99Tc. In the case of a release of radioactivity from a power reactor or used fuel, only some elements are released; as a result, the isotopic signature of the radioactivity is very different from an open air nuclear detonation, where all the fission products are dispersed.
Nonbonding orbital Electron transitions Non-bonding_orbital > Electron transitions Electrons in molecular non-bonding orbitals can undergo electron transitions such as n→σ* or n→π* transitions. For example, n→π* transitions can be seen in ultraviolet-visible spectroscopy of compounds with carbonyl groups, although absorbance is fairly weak.
Component (graph theory) Number of components Connected_component_(graph_theory) > Number of components A graph can be interpreted as a topological space in multiple ways, for instance by placing its vertices as points in general position in three-dimensional Euclidean space and representing its edges as line segments between those points. The components of a graph can be generalized through these interpretations as the topological connected components of the corresponding space; these are equivalence classes of points that cannot be separated by pairs of disjoint closed sets. Just as the number of connected components of a topological space is an important topological invariant, the zeroth Betti number, the number of components of a graph is an important graph invariant, and in topological graph theory it can be interpreted as the zeroth Betti number of the graph.The number of components arises in other ways in graph theory as well.
Immunologic adjuvant Adaptive immune response Immunologic_adjuvant > Adaptive immune response First, adjuvants may help in the translocation of antigens to the lymph nodes where they can be recognized by T cells. This will ultimately lead to greater T cell activity resulting in a heightened clearance of pathogen throughout the organism. Second, adjuvants may provide physical protection to antigens which grants the antigen a prolonged delivery.
Monte Carlo methods in finance American options Monte_Carlo_methods_in_finance > Applicability > American options Monte-Carlo methods are harder to use with American options. This is because, in contrast to a partial differential equation, the Monte Carlo method really only estimates the option value assuming a given starting point and time. However, for early exercise, we would also need to know the option value at the intermediate times between the simulation start time and the option expiry time. In the Black–Scholes PDE approach these prices are easily obtained, because the simulation runs backwards from the expiry date. In Monte-Carlo this information is harder to obtain, but it can be done for example using the least squares algorithm of Carriere (see link to original paper) which was made popular a few years later by Longstaff and Schwartz (see link to original paper).
Neural ensemble Encoding Neuronal_ensemble > Encoding This problem is solved by the brain having billions of neurons. Information processing by the brain is population processing, and it is also distributed – in many cases each neuron knows a little bit about everything, and the more neurons participate in a job, the more precise the information encoding. In the distributed processing scheme, individual neurons may exhibit neuronal noise, but the population as a whole averages this noise out.
TP53 gene Role in disease TP53_gene > Role in disease The degradation of the p53 protein is associated with binding of MDM2. In a negative feedback loop, MDM2 itself is induced by the p53 protein. Mutant p53 proteins often fail to induce MDM2, causing p53 to accumulate at very high levels.
Alternative DNS root eDNS Alternative_DNS_root > Defunct implementations > eDNS eDNS (Enhanced Domain Name Service) was founded by a coalition of ISPs led by Karl Denninger of the Chicago-area MCSNet. It ceased operation in 1998. It served the following domains: biz (general business use), corp (corporations), fam (for and about family), k12 (for and about children), npo (non-profit organizations), per (personal domains), web (web-based sites, Web pages).
Electromagnetic motor Torque motor Electrical_motor > Externally commutated AC machine > Induction motor > Torque motor A torque motor can operate indefinitely while stalled, that is, with the rotor blocked from turning, without incurring damage. In this mode of operation, the motor applies a steady torque to the load. A common application is the supply- and take-up reel motors in a tape drive. In this application, driven by a low voltage, the characteristics of these motors apply a steady light tension to the tape whether or not the capstan is feeding tape past the tape heads.
The Annotated Turing Table of contents The_Annotated_Turing > Table of contents Part I. Foundations Chapter 1: This Tomb Holds Diophantus Chapter 2: The Irrational and the Transcendental Chapter 3: Centuries of Progress Part II. Computable Numbers Chapter 4: The Education of Alan Turing Chapter 5: Machines at Work Chapter 6: Addition and Multiplication Chapter 7: Also Known as Subroutines Chapter 8: Everything is a Number Chapter 9: The Universal Machine Chapter 10: Computers and Computability Chapter 11: Of Machines and Men Part III. Das Entscheidungsproblem Chapter 12: Logic and Computability Chapter 13: Computable Functions Chapter 14: The Major Proof Chapter 15: The Lambda Calculus Chapter 16: Conceiving the Continuum Part IV. And Beyond Chapter 17: Is Everything a Turing Machine? Chapter 18: The Long Sleep of Diophantus
Decentralized identity Technical aspects Decentralized_identity > Technical aspects This reduces the unintended sharing of users' personal data. This is contrasted with the centralized identity paradigm where identity is provided by some outside entity.In an SSI system, holders generate and control unique identifiers called decentralized identifiers. Most SSI systems are decentralized, where the credentials are managed using crypto wallets and verified using public-key cryptography anchored on a distributed ledger. The credentials may contain data from an issuer's database, a social media account, a history of transactions on an e-commerce site, or attestation from friends or colleagues.
Protein hydroxylation Synthetic hydroxylations Protein_hydroxylation > Hydroxylation reactions > Synthetic hydroxylations Installing hydroxyl groups into organic compounds can be effected by various metal catalysts. Many such catalysts are biomimetic, i.e. they are inspired by or intended to mimic enzymes such as cytochrome P450.Whereas many hydroxylations insert O atoms into C−H bonds, some reactions add OH groups to unsaturated substrates. The Sharpless dihydroxylation is such a reaction: it converts alkenes into diols. The hydroxy groups are provided by hydrogen peroxide, which adds across the double bond of alkenes.
Hypoxia (environmental) Aquatic hypoxia Hypoxia_(environmental) > Aquatic hypoxia Oxygen depletion is a phenomenon that occurs in aquatic environments as dissolved oxygen (DO; molecular oxygen dissolved in the water) becomes reduced in concentration to a point where it becomes detrimental to aquatic organisms living in the system. Dissolved oxygen is typically expressed as a percentage of the oxygen that would dissolve in the water at the prevailing temperature and salinity (both of which affect the solubility of oxygen in water; see oxygen saturation and underwater). An aquatic system lacking dissolved oxygen (0% saturation) is termed anaerobic, reducing, or anoxic; a system with low concentration—in the range between 1 and 30% saturation—is called hypoxic or dysoxic. Most fish cannot live below 30% saturation since they rely on oxygen to derive energy from their nutrients.
Named data networking Overview Named_data_networking > Overview Today's Internet's hourglass architecture centers on a universal network layer, IP, which implements the minimal functionality necessary for global inter-connectivity. The contemporary Internet architecture revolves around a host-based conversation model, created in the 1970s to allow geographically distributed users to use a few big, immobile computers. This thin waist enabled the Internet's explosive growth by allowing both lower and upper layer technologies to innovate independently. However, IP was designed to create a communication network, where packets named only communication endpoints.
Thomas Bayes Biography Thomas_Bayes > Biography Historian Stephen Stigler thinks that Bayes became interested in the subject while reviewing a work written in 1755 by Thomas Simpson, but George Alfred Barnard thinks he learned mathematics and probability from a book by Abraham de Moivre. Others speculate he was motivated to rebut David Hume's argument against believing in miracles on the evidence of testimony in An Enquiry Concerning Human Understanding.
Reactive programming Degrees of explicitness Reactive_programming > Concepts > Degrees of explicitness Reactive programming languages can range from very explicit ones where data flows are set up by using arrows, to implicit where the data flows are derived from language constructs that look similar to those of imperative or functional programming. For example, in implicitly lifted functional reactive programming (FRP) a function call might implicitly cause a node in a data flow graph to be constructed. Reactive programming libraries for dynamic languages (such as the Lisp "Cells" and Python "Trellis" libraries) can construct a dependency graph from runtime analysis of the values read during a function's execution, allowing data flow specifications to be both implicit and dynamic. Sometimes the term reactive programming refers to the architectural level of software engineering, where individual nodes in the data flow graph are ordinary programs that communicate with each other.
Aldosterone escape Summary Aldosterone_escape In physiology, aldosterone escape is a term that has been used to refer to two distinct phenomena involving aldosterone that are exactly opposite each other: Escape from the sodium-retaining effects of excess aldosterone (or other mineralocorticoids) in primary hyperaldosteronism, manifested by volume and/or pressure natriuresis. The inability of ACE inhibitor therapy to reliably suppress aldosterone release, for example, in patients with heart failure or diabetes, usually manifested by increased salt and water retention. This latter sense may rather be termed refractory hyperaldosteronism.In patients with hyperaldosteronism, chronic exposure to excess aldosterone does not cause edema as might be expected.
Robotic Process Automation Summary Robotic_automation_software In contrast, RPA systems develop the action list by watching the user perform that task in the application's graphical user interface (GUI), and then perform the automation by repeating those tasks directly in the GUI. This can lower the barrier to the use of automation in products that might not otherwise feature APIs for this purpose. RPA tools have strong technical similarities to graphical user interface testing tools. These tools also automate interactions with the GUI, and often do so by repeating a set of demonstration actions performed by a user. RPA tools differ from such systems in that they allow data to be handled in and between multiple applications, for instance, receiving email containing an invoice, extracting the data, and then typing that into a bookkeeping system.
Navigation function Stochastic Navigation Function Navigation_function > Stochastic Navigation Function If we assume the transition dynamics of the system or the cost function as subjected to noise, we obtain a stochastic optimal control problem with a cost J ( x t , u t ) {\displaystyle J(x_{t},u_{t})} and dynamics f {\displaystyle f} . In the field of reinforcement learning the cost is replaced by a reward function R ( x t , u t ) {\displaystyle R(x_{t},u_{t})} and the dynamics by the transition probabilities P ( x t + 1 \| x t , u t ) {\displaystyle P(x_{t+1}\|x_{t},u_{t})} .
Chemical reaction kinetics Surface area of solid state Chemical_reaction_kinetics > Factors affecting reaction rate > Surface area of solid state Also, fireworks manufacturers modify the surface area of solid reactants to control the rate at which the fuels in fireworks are oxidised, using this to create diverse effects. For example, finely divided aluminium confined in a shell explodes violently. If larger pieces of aluminium are used, the reaction is slower and sparks are seen as pieces of burning metal are ejected.
Electromagnetic attraction Classical electrodynamics Maxwell's_theory_of_electromagnetism > Classical electrodynamics In 1600, William Gilbert proposed, in his De Magnete, that electricity and magnetism, while both capable of causing attraction and repulsion of objects, were distinct effects. Mariners had noticed that lightning strikes had the ability to disturb a compass needle. The link between lightning and electricity was not confirmed until Benjamin Franklin's proposed experiments in 1752 were conducted on 10 May 1752 by Thomas-François Dalibard of France using a 40-foot-tall (12 m) iron rod instead of a kite and he successfully extracted electrical sparks from a cloud.One of the first to discover and publish a link between man-made electric current and magnetism was Gian Romagnosi, who in 1802 noticed that connecting a wire across a voltaic pile deflected a nearby compass needle. However, the effect did not become widely known until 1820, when Ørsted performed a similar experiment.
Egg sac Central nervous system Egg_sac > Description > Central nervous system The basic arthropod central nervous system consists of a pair of nerve cords running below the gut, with paired ganglia as local control centers in all segments; a brain formed by fusion of the ganglia for the head segments ahead of and behind the mouth, so that the esophagus is encircled by this conglomeration of ganglia. Except for the primitive Mesothelae, of which the Liphistiidae are the sole surviving family, spiders have the much more centralized nervous system that is typical of arachnids: all the ganglia of all segments behind the esophagus are fused, so that the cephalothorax is largely filled with nervous tissue and there are no ganglia in the abdomen; in the Mesothelae, the ganglia of the abdomen and the rear part of the cephalothorax remain unfused.Despite the relatively small central nervous system, some spiders (like Portia) exhibit complex behaviour, including the ability to use a trial-and-error approach.
Bead sort Complexity Bead_sort > Complexity Bead sort can be implemented with four general levels of complexity, among others: O(1): The beads are all moved simultaneously in the same time unit, as would be the case with the simple physical example above. This is an abstract complexity, and cannot be implemented in practice. O( n {\displaystyle {\sqrt {n}}} ): In a realistic physical model that uses gravity, the time it takes to let the beads fall is proportional to the square root of the maximum height, which is proportional to n. O(n): The beads are moved one row at a time. This is the case used in the analog and digital hardware solutions.
Euclidean vector Overview Vector_quantity > Overview Thus two arrows A B ⟶ {\displaystyle {\stackrel {\,\longrightarrow }{AB}}} and A ′ B ′ ⟶ {\displaystyle {\stackrel {\,\longrightarrow }{A'B'}}} in space represent the same free vector if they have the same magnitude and direction: that is, they are equipollent if the quadrilateral ABB′A′ is a parallelogram. If the Euclidean space is equipped with a choice of origin, then a free vector is equivalent to the bound vector of the same magnitude and direction whose initial point is the origin. The term vector also has generalizations to higher dimensions, and to more formal approaches with much wider applications.
Gene isoform PTEN Gene_isoform > Examples > PTEN Phosphatase and tensin homolog (Pten) is originally identified as a tumor suppressor gene. Recent studies found that Pten also suppressed axon regeneration in retinal ganglion cells, corticospinal tract, and DRG neurons. So far 3 Pten isoforms (Pten, PtenJ1, and Pten J2) have been identified and analyzed.
Weight-balanced tree Set operations and bulk operations Weight-balanced_tree > Set operations and bulk operations Several set operations have been defined on weight-balanced trees: union, intersection and set difference. Then fast bulk operations on insertions or deletions can be implemented based on these set functions. These set operations rely on two helper operations, Split and Join. With the new operations, the implementation of weight-balanced trees can be more efficient and highly-parallelizable.
Irregular moon Temporary captures Irregular_satellites > Orbits > Temporary captures The capture of an asteroid from a heliocentric orbit is not always permanent. According to simulations, temporary satellites should be a common phenomenon. The only observed examples are 2006 RH120 and 2020 CD3, which were temporary satellites of Earth discovered in 2006 and 2020, respectively.
Evolving digital ecological network Digital organisms Evolving_digital_ecological_network > Implementation > Digital organisms While most mutations are detrimental, mutants will occasionally have higher fitness than their parents, thereby providing the basis for natural selection with all of the necessary components for Darwinian evolution. Digital organisms can acquire random binary numbers from the environment and are able to manipulate them using their genetic instructions, including the logic instruction NAND. With only this instruction, digital organisms can compute any other task by stringing together various operations because NAND is a universal logic function. If the output of processing random numbers from the environment corresponds to the result of a particular logic task, then that task is incorporated into the set of tasks the organism performs, which in turn, defines part of its phenotype.
End stage kidney disease Stages End-stage_renal_disease > Diagnosis > Stages Kidney damage is defined as pathological abnormalities or markers of damage, including abnormalities in blood or urine tests or imaging studies. Stage 3: Moderate reduction in GFR (30–59 mL/min/1.73 m2):. British guidelines distinguish between stage 3A (GFR 45–59) and stage 3B (GFR 30–44) for purposes of screening and referral.
Combination Number of ways to put objects into bins Combination > Number of ways to put objects into bins }{k_{1}!\,k_{2}!\cdots k_{m}!}}} . The binomial coefficient is the special case where k items go into the chosen bin and the remaining n − k {\displaystyle n-k} items go into the unchosen bin:
Electrochemical reduction Oxidation and reduction Galvanic_couple > Principles > Oxidation and reduction Chlorine accepts the electron and its oxidation state is reduced to −1. The sign of the oxidation state (positive/negative) actually corresponds to the value of each ion's electronic charge. The attraction of the differently charged sodium and chlorine ions is the reason they then form an ionic bond.
Data Matrix Applications Data_matrix_(computer) > Applications The most popular application for Data Matrix is marking small items, due to the code's ability to encode fifty characters in a symbol that is readable at 2 or 3 mm2 (0.003 or 0.005 sq in) and the fact that the code can be read with only a 20% contrast ratio. A Data Matrix is scalable; commercial applications exist with images as small as 300 micrometres (0.012 in) (laser etched on a 600-micrometre (0.024 in) silicon device) and as large as a 1 metre (3 ft) square (painted on the roof of a boxcar). Fidelity of the marking and reading systems are the only limitation.
Generative model Discriminative models Generative_model > Types > Discriminative models k-nearest neighbors algorithm Logistic regression Support Vector Machines Decision Tree Learning Random Forest Maximum-entropy Markov models Conditional random fields
Forensic epidemiology Hill viewpoints Forensic_epidemiology > Methods and principles > Causal methodology > Hill viewpoints It should “ make sense” given current knowledge Analogy: The results of a previously described causal relationship may be translatable to the circumstances of a current investigation Consistency: The repeated observation of the investigated relationship in different circumstances or across a number of studies lends strength to a causal inference Specificity: The degree to which the exposure is associated with a particular outcome Biological plausibility: The extent to which the observed association can be explained by known scientific principles Experiment: In some cases there may be evidence from randomized experiments (i.e., drug trials) Dose response: The probability, frequency, or severity of the outcome increases with increased amount of exposureSubsequent authors have added the feature of Challenge/ Dechallenge/ Rechallenge for circumstances when the exposure is repeated over time and there is the ability to observe the associated outcome response, as might occur with an adverse reaction to a medication. Additional considerations when assessing an association are the potential impact of confounding and bias in the data, which can obscure a true relationship. Confounding refers to a situation in which an association between an exposure and outcome is all or partly the result of a factor that affects the outcome but is unaffected by the exposure.
Speed of gravity Early theories Speed_of_gravity > Electrodynamical analogies > Early theories However, those hypotheses were rejected.However, a more important variation of those attempts was the theory of Paul Gerber, who derived in 1898 the identical formula, which was also derived later by Einstein for the perihelion advance. Based on that formula, Gerber calculated a propagation speed for gravity of 305000 km/s, i.e. practically the speed of light. But Gerber's derivation of the formula was faulty, i.e., his conclusions did not follow from his premises, and therefore many (including Einstein) did not consider it to be a meaningful theoretical effort. Additionally, the value it predicted for the deflection of light in the gravitational field of the sun was too high by the factor 3/2.
Georgi–Glashow model Explicit Embedding of the Standard Model (SM) Georgi–Glashow_model > Explicit Embedding of the Standard Model (SM) Note that the T i {\displaystyle T_{i}} are not SM particles and are thus a prediction of the Georgi–Glashow model. The SM gauge fields can be embedded explicitly as well. For that we recall a gauge field transforms as an adjoint, and thus can be written as A μ a T a {\displaystyle A_{\mu }^{a}T^{a}} with T a {\displaystyle T^{a}} the S U ( 5 ) {\displaystyle SU(5)} generators.
Minute ventilation Physiological significance of minute volume Respiratory_minute_volume > Physiological significance of minute volume Blood carbon dioxide (PaCO2) levels generally vary inversely with minute volume. For example, a person with increased minute volume (e.g. due to hyperventilation) should demonstrate a lower blood carbon dioxide level. The healthy human body will alter minute volume in an attempt to maintain physiologic homeostasis. A normal minute volume while resting is about 5–8 liters per minute in humans.
P value Basic concepts P_value > Basic concepts In statistics, every conjecture concerning the unknown probability distribution of a collection of random variables representing the observed data X {\displaystyle X} in some study is called a statistical hypothesis. If we state one hypothesis only and the aim of the statistical test is to see whether this hypothesis is tenable, but not to investigate other specific hypotheses, then such a test is called a null hypothesis test. As our statistical hypothesis will, by definition, state some property of the distribution, the null hypothesis is the default hypothesis under which that property does not exist. The null hypothesis is typically that some parameter (such as a correlation or a difference between means) in the populations of interest is zero.
Biology Genes, development, and evolution Biological_research > Genetics > Genes, development, and evolution Development is the process by which a multicellular organism (plant or animal) goes through a series of changes, starting from a single cell, and taking on various forms that are characteristic of its life cycle. There are four key processes that underlie development: Determination, differentiation, morphogenesis, and growth. Determination sets the developmental fate of a cell, which becomes more restrictive during development. Differentiation is the process by which specialized cells from less specialized cells such as stem cells.
Homeostatic response Summary Predictive_homeostasis The receptor is the sensing component that monitors and responds to changes in the environment, either external or internal. Receptors include thermoreceptors and mechanoreceptors. Control centers include the respiratory center and the renin-angiotensin system.
Sustainable lifestyle Power Sustainable_living > Power When on a small scale, however, in the form of single turbines, hydroelectricity is very sustainable. Single water turbines or even a group of single turbines are not environmentally or socially disruptive. On an individual household basis, single turbines are the probably the only economically feasible route (but can have high paybacks and is one of the most efficient methods of renewable energy production).
Methotrexate Adverse effects Methotrexate > Adverse effects Guidelines have been updated to state that it is safe for a male partner to take at any point while trying to conceive.Central nervous system reactions to methotrexate have been reported, especially when given via the intrathecal route (directly into the cerebrospinal fluid), which include myelopathies and leukoencephalopathies. It has a variety of cutaneous side effects, particularly when administered in high doses.Another little understood but serious possible adverse effect of methotrexate is neurological damage and memory loss. Neurotoxicity may result from the drug crossing the blood–brain barrier and damaging neurons in the cerebral cortex. People with cancer who receive the medication often nickname these effects "chemo brain" or "chemo fog".
Glossary of prestressed concrete terms E Glossary_of_prestressed_concrete_terms > E eccentricity The distance between the centre of gravity of the concrete cross-section and the centroid of its prestressing element(s), at any point along the member. : 27 elastic modulus See Young's Modulus. elongation See tendon extension.
Classical analysis Sequences and limits Mathematical_Analysis > Important concepts > Sequences and limits A sequence is an ordered list. Like a set, it contains members (also called elements, or terms). Unlike a set, order matters, and exactly the same elements can appear multiple times at different positions in the sequence.
Symbol grounding problem Brentano's notion of intentionality Symbol_grounding > Brentano's notion of intentionality Damasio adds the notion of biologic homeostasis to this discussion, presenting it as an automated bodily regulation process providing intentionality to a mind via emotions. Homeostasis is the mechanism that keeps all bodily processes in healthy balance. All of our actions and perceptions will be automatically "evaluated" by our body hardware according to their contribution to homeostasis.
Casimir vacuum Regularization Dynamical_Casimir_Effect > Regularization Other, suitably smooth, regulators may be used as well. The zeta function regulator is completely unsuited for numerical calculations, but is quite useful in theoretical calculations.
Crystal form Crystal faces, shapes and crystallographic forms Crystal_phase > Crystal faces, shapes and crystallographic forms Galena also sometimes crystallizes as octahedrons, and the eight faces of the octahedron belong to another crystallographic form reflecting a different symmetry of the isometric system. A crystallographic form is described by placing the Miller indices of one of its faces within brackets. For example, the octahedral form is written as {111}, and the other faces in the form are implied by the symmetry of the crystal.
Heisenberg's inequality History Quantum_uncertainty > History Heisenberg's paper did not admit any unobservable quantities like the exact position of the electron in an orbit at any time; he only allowed the theory to talk about the Fourier components of the motion. Since the Fourier components were not defined at the classical frequencies, they could not be used to construct an exact trajectory, so that the formalism could not answer certain overly precise questions about where the electron was or how fast it was going, without losing some information about one or the other variable.According to one account: "Heisenberg's paper marked a radical departure from previous attempts to solve atomic problems by making use of observable quantities only. 'My entire meagre efforts go toward killing off and suitably replacing the concept of the orbital paths that one cannot observe,' he wrote in a letter dated 9 July 1925.
Fermi resonance Ketones Fermi_resonance > Examples > Ketones High-resolution IR spectra of most ketones reveal that the "carbonyl band" is split into a doublet. The peak separation is usually only a few cm−1. This splitting arises from the mixing of νCO and the overtone of HCH bending modes.
Ibercivis Completed projects Ibercivis > Projects > Completed projects The Bioinformatics Unit of the Centro de Biología Molecular Severo Ochoa (CSIC-UAM) developed a platform to allow the automatic simulation of interactions of proteins and small molecules. Its purpose was to find effective drugs to treat serious illnesses, such as cancer. Materials: simulation of magnetic systems: the Materials application aided physicists from the Universidad Complutense de Madrid, Universidad de Extremadura and the Institute for Biocomputation and Physics of Complex Systems in discovering how non-magnetic impurities in magnetic materials modify the properties of their transition from a magnetic state to a non-magnetic one.
Tensor (machine learning) In fully connected layers Tensor_(machine_learning) > Definition > In fully connected layers In this example the unit values are scalars while the tensor takes on the dimensions of the network layers: x n ↦ X ∈ R 1 × N , {\displaystyle x_{n}\mapsto {\mathcal {X}}\in \mathbb {R} ^{1\times N},} y n ↦ Y ∈ R M × 1 , {\displaystyle y_{n}\mapsto {\mathcal {Y}}\in \mathbb {R} ^{M\times 1},} u n ↦ U ∈ R N × M . {\displaystyle u_{n}\mapsto {\mathcal {U}}\in \mathbb {R} ^{N\times M}.} In this notation, the output values can be computed as a tensor product of the input and weight tensors: Y = f ( X U ) .
Ambigram 3-dimensional ambigrams Ambigram > Types > 3-dimensional ambigrams A 3D ambigram is a design where an object is presented that will appear to read several letters or words when viewed from different angles. Such designs can be generated using constructive solid geometry, a technique used in solid modeling, and then physically constructed with the rapid prototyping method. 3-dimensional ambigram sculptures can also be achieved in plastic arts. They are volume ambigrams. The original 1979 edition of Hofstadter's Gödel, Escher, Bach featured two 3-D ambigrams on the cover.
Machine learning Robot learning Machine_learning > Approaches > Other types > Robot learning Robot learning is inspired by a multitude of machine learning methods, starting from supervised learning, reinforcement learning, and finally meta-learning (e.g. MAML).
Molecular mechanics Functional form Molecular_mechanics > Functional form The dihedral or torsional terms typically have multiple minima and thus cannot be modeled as harmonic oscillators, though their specific functional form varies with the implementation. This class of terms may include improper dihedral terms, which function as correction factors for out-of-plane deviations (for example, they can be used to keep benzene rings planar, or correct geometry and chirality of tetrahedral atoms in a united-atom representation). The non-bonded terms are much more computationally costly to calculate in full, since a typical atom is bonded to only a few of its neighbors, but interacts with every other atom in the molecule.
Gene Origins of new genes Genetic_transmission > Molecular evolution > Origins of new genes Over long evolutionary time periods, de novo gene birth may be responsible for a significant fraction of taxonomically restricted gene families.Horizontal gene transfer refers to the transfer of genetic material through a mechanism other than reproduction. This mechanism is a common source of new genes in prokaryotes, sometimes thought to contribute more to genetic variation than gene duplication. It is a common means of spreading antibiotic resistance, virulence, and adaptive metabolic functions. Although horizontal gene transfer is rare in eukaryotes, likely examples have been identified of protist and alga genomes containing genes of bacterial origin.
Infectious diseases Microbial culture Infectious_disease > Diagnosis > Microbial culture A single bacterium will grow into a visible mound on the surface of the plate called a colony, which may be separated from other colonies or melded together into a "lawn". The size, color, shape and form of a colony is characteristic of the bacterial species, its specific genetic makeup (its strain), and the environment that supports its growth. Other ingredients are often added to the plate to aid in identification.
Directed acyclic graphs Data compression Directed_Acyclic_Graph > Applications > Data compression Directed acyclic graphs may also be used as a compact representation of a collection of sequences. In this type of application, one finds a DAG in which the paths form the given sequences. When many of the sequences share the same subsequences, these shared subsequences can be represented by a shared part of the DAG, allowing the representation to use less space than it would take to list out all of the sequences separately. For example, the directed acyclic word graph is a data structure in computer science formed by a directed acyclic graph with a single source and with edges labeled by letters or symbols; the paths from the source to the sinks in this graph represent a set of strings, such as English words.
Matrix 2 of 5 Summary Matrix_2_of_5 Matrix 2 of 5 (also known as Code 2 of 5 Matrix.) is a variable length, discrete, two width symbology. Matrix 2 of 5 is a subset of two-out-of-five codes. Unlike Industrial 2 of 5 code, Matrix 2 of 5 can encode data not only with black bars but with white spaces.
Oddo–Harkins rule Definition Oddo–Harkins_rule > Definition All atoms bigger than hydrogen are formed in stars or supernovae through nucleosynthesis, when gravity, temperature and pressure reach levels high enough to fuse protons and neutrons together. Protons and neutrons form the atomic nucleus, which accumulates electrons to form atoms. The number of protons in the nucleus, called atomic number, uniquely identifies a chemical element. The Oddo–Harkins rule argues that elements with odd atomic numbers have one unpaired proton and so are more likely to capture another, increasing their atomic number. It is possible that in elements with even atomic numbers, protons are paired, with each member of the pair balancing the spin of the other; even parity thus enhances nucleon stability.
Definite Integrals Summary Integral_over_time Today integration is used in a wide variety of scientific fields. The integrals enumerated here are called definite integrals, which can be interpreted as the signed area of the region in the plane that is bounded by the graph of a given function between two points in the real line. Conventionally, areas above the horizontal axis of the plane are positive while areas below are negative.
Regularization perspectives on support vector machines Special properties of the hinge loss Regularization_perspectives_on_support_vector_machines > Special properties of the hinge loss The hinge loss, V ( y i , f ( x i ) ) = ( 1 − y f ( x ) ) + {\displaystyle V{\big (}y_{i},f(x_{i}){\big )}={\big (}1-yf(x){\big )}_{+}} , where ( s ) + = max ( s , 0 ) {\displaystyle (s)_{+}=\max(s,0)} , provides such a convex relaxation. In fact, the hinge loss is the tightest convex upper bound to the 0–1 misclassification loss function, and with infinite data returns the Bayes-optimal solution: f b ( x ) = { 1 , p ( 1 ∣ x ) > p ( − 1 ∣ x ) , − 1 , p ( 1 ∣ x ) < p ( − 1 ∣ x ) . {\displaystyle f_{b}(x)={\begin{cases}1,&p(1\mid x)>p(-1\mid x),\\-1,&p(1\mid x)
Fetal liver Metabolism Hepatic_metabolism > Functions > Metabolism The liver plays a major role in carbohydrate, protein, amino acid, and lipid metabolism.
Broken heart syndrome Diagnosis Takotsubo_cardiomyopathy > Diagnosis It classically mimics ST-segment elevation myocardial infarction, and is characterised by acute onset of transient ventricular apical wall motion abnormalities (ballooning) accompanied by chest pain, shortness of breath, ST-segment elevation, T-wave inversion or QT-interval prolongation on ECG. Cardiac enzymes are usually negative and are moderate at worst, and cardiac catheterization usually shows absence of significant coronary artery disease.The diagnosis is made by the pathognomonic wall motion abnormalities, in which the base of the left ventricle is contracting normally or is hyperkinetic while the remainder of the left ventricle is akinetic or dyskinetic. This is accompanied by the lack of significant coronary artery disease that would explain the wall motion abnormalities. Although apical ballooning has been described classically as the angiographic manifestation of takotsubo, it has been shown that left ventricular dysfunction in this syndrome includes not only the classic apical ballooning, but also different angiographic morphologies such as mid-ventricular ballooning and, rarely, local ballooning of other segments.The ballooning patterns were classified by Shimizu et al. as takotsubo type for apical akinesia and basal hyperkinesia, reverse takotsubo for basal akinesia and apical hyperkinesia, mid-ventricular type for mid-ventricular ballooning accompanied by basal and apical hyperkinesia, and localised type for any other segmental left ventricular ballooning with clinical characteristics of takotsubo-like left ventricular dysfunction.In short, the main criteria for the diagnosis of takotsubo cardiomyopathy are: the patient must have experienced a stressor before the symptoms began to arise; the patient's ECG reading must show abnormalities from a normal heart; the patient must not show signs of coronary blockage or other common causes of heart troubles; the levels of cardiac enzymes in the heart must be elevated or irregular; and the patient must recover complete contraction and be functioning normally in a short amount of time.
Natural circulation Natural convection Free_convection > Mechanisms > Natural convection All require the presence of an environment which experiences g-force (proper acceleration). The difference of density in the fluid is the key driving mechanism. If the differences of density are caused by heat, this force is called as "thermal head" or "thermal driving head."
Enzyme engineering Chemical mutagenesis Enzyme_engineering > Approaches > Asexual methods > Chemical mutagenesis Chemical mutagenesis involves the use of chemical agents to introduce mutations into genetic sequences. Examples of chemical mutagens follow. Sodium bisulfate is effective at mutating G/C rich genomic sequences.
Androgen receptor Non-genomic Androgen_receptors > Function > Mechanism of action > Non-genomic More recently, androgen receptors have been shown to have a second mode of action. As has been also found for other steroid hormone receptors such as estrogen receptors, androgen receptors can have actions that are independent of their interactions with DNA. Androgen receptors interact with certain signal transduction proteins in the cytoplasm. Androgen binding to cytoplasmic androgen receptors can cause rapid changes in cell function independent of changes in gene transcription, such as changes in ion transport. Regulation of signal transduction pathways by cytoplasmic androgen receptors can indirectly lead to changes in gene transcription, for example, by leading to phosphorylation of other transcription factors.
Electrostatic Interaction Atomic forces Coulomb_repulsion > Atomic forces Coulomb's law holds even within atoms, correctly describing the force between the positively charged atomic nucleus and each of the negatively charged electrons. This simple law also correctly accounts for the forces that bind atoms together to form molecules and for the forces that bind atoms and molecules together to form solids and liquids. Generally, as the distance between ions increases, the force of attraction, and binding energy, approach zero and ionic bonding is less favorable. As the magnitude of opposing charges increases, energy increases and ionic bonding is more favorable.
Classical Lie group The classical groups Classical_Lie_group > The classical groups In the sequel, the determinant 1 condition is not used consistently in the interest of greater generality. The complex classical groups are SL(n, C), SO(n, C) and Sp(n, C). A group is complex according to whether its Lie algebra is complex.
Cell migration Membrane flow model (B) Cell_migration > Molecular processes of migration > Membrane flow model (B) The leading edge at the front of a migrating cell is also the site at which membrane from internal membrane pools is returned to the cell surface at the end of the endocytic cycle. This suggests that extension of the leading edge occurs primarily by addition of membrane at the front of the cell. If so, the actin filaments that form there might stabilize the added membrane so that a structured extension, or lamella, is formed — rather than a bubble-like structure (or bleb) at its front. For a cell to move, it is necessary to bring a fresh supply of "feet" (proteins called integrins, which attach a cell to the surface on which it is crawling) to the front.
Barycentric coordinate system Applications Barycentric_coordinate_system_(mathematics) > Generalized barycentric coordinates > Applications Generalized barycentric coordinates have applications in computer graphics and more specifically in geometric modelling. Often, a three-dimensional model can be approximated by a polyhedron such that the generalized barycentric coordinates with respect to that polyhedron have a geometric meaning. In this way, the processing of the model can be simplified by using these meaningful coordinates. Barycentric coordinates are also used in geophysics.
Interstellar Travel Feasibility Interstellar_space_travel > Feasibility Moving at a speed close to the speed of light and encountering even a tiny stationary object like a grain of sand will have fatal consequences. For example, a gram of matter moving at 90% of the speed of light contains a kinetic energy corresponding to a small nuclear bomb (around 30kt TNT). One of the major stumbling blocks is having enough Onboard Spares & Repairs facilities for such a lengthy time journey assuming all other considerations are solved, without access to all the resources available on Earth.
Double logarithmic Applications Log–log_plot > Applications These graphs are useful when the parameters a and b need to be estimated from numerical data. Specifications such as this are used frequently in economics. One example is the estimation of money demand functions based on inventory theory, in which it can be assumed that money demand at time t is given by where M is the real quantity of money held by the public, R is the rate of return on an alternative, higher yielding asset in excess of that on money, Y is the public's real income, U is an error term assumed to be lognormally distributed, A is a scale parameter to be estimated, and b and c are elasticity parameters to be estimated. Taking logs yields where m = log M, a = log A, r = log R, y = log Y, and u = log U with u being normally distributed.
Binary functions Category theory Binary_functions > Category theory In category theory, n-ary functions generalise to n-ary morphisms in a multicategory. The interpretation of an n-ary morphism as an ordinary morphisms whose domain is some sort of product of the domains of the original n-ary morphism will work in a monoidal category. The construction of the derived morphisms of one variable will work in a closed monoidal category. The category of sets is closed monoidal, but so is the category of vector spaces, giving the notion of bilinear transformation above.
Fourier transforms Units and duality Fourier_transformations > Properties of the Fourier transform > Units and duality That is to say, there are two versions of the real line: one which is the range of t and measured in units of t, and the other which is the range of ξ and measured in inverse units to the units of t. These two distinct versions of the real line cannot be equated with each other. Therefore, the Fourier transform goes from one space of functions to a different space of functions: functions which have a different domain of definition. In general, ξ must always be taken to be a linear form on the space of its domain, which is to say that the second real line is the dual space of the first real line.
Warfarin sodium Pharmacokinetics Warfarin_sodium > Pharmacology > Pharmacokinetics Warfarin has a long half-life and need only be given once a day. Heparin can also cause a prothrombotic condition, heparin-induced thrombocytopenia (an antibody-mediated decrease in platelet levels), which increases the risk for thrombosis.
Research ethics Scientific research Academic_research > Forms of research > Scientific research Generally, a hypothesis is used to make predictions that can be tested by observing the outcome of an experiment. If the outcome is inconsistent with the hypothesis, then the hypothesis is rejected (see falsifiability). However, if the outcome is consistent with the hypothesis, the experiment is said to support the hypothesis.
Mean absolute deviation Median absolute deviation around the median Average_absolute_deviation > Median absolute deviation around a central point > Median absolute deviation around the median The median absolute deviation (also MAD) is the median of the absolute deviation from the median. It is a robust estimator of dispersion. For the example {2, 2, 3, 4, 14}: 3 is the median, so the absolute deviations from the median are {1, 1, 0, 1, 11} (reordered as {0, 1, 1, 1, 11}) with a median of 1, in this case unaffected by the value of the outlier 14, so the median absolute deviation is 1. For a symmetric distribution, the median absolute deviation is equal to half the interquartile range.
ZFS Summary ZFS > Features > Summary Examples of features specific to ZFS include: Designed for long-term storage of data, and indefinitely scaled datastore sizes with zero data loss, and high configurability. Hierarchical checksumming of all data and metadata, ensuring that the entire storage system can be verified on use, and confirmed to be correctly stored, or remedied if corrupt. Checksums are stored with a block's parent block, rather than with the block itself. This contrasts with many file systems where checksums (if held) are stored with the data so that if the data is lost or corrupt, the checksum is also likely to be lost or incorrect.
Jacobian curve Summary Jacobian_curve In mathematics, the Jacobi curve is a representation of an elliptic curve different from the usual one defined by the Weierstrass equation. Sometimes it is used in cryptography instead of the Weierstrass form because it can provide a defence against simple and differential power analysis style (SPA) attacks; it is possible, indeed, to use the general addition formula also for doubling a point on an elliptic curve of this form: in this way the two operations become indistinguishable from some side-channel information. The Jacobi curve also offers faster arithmetic compared to the Weierstrass curve. The Jacobi curve can be of two types: the Jacobi intersection, that is given by an intersection of two surfaces, and the Jacobi quartic.
Rectifier (neural networks) Advantages Rectified_linear_unit > Advantages Sparse activation: For example, in a randomly initialized network, only about 50% of hidden units are activated (have a non-zero output). Better gradient propagation: Fewer vanishing gradient problems compared to sigmoidal activation functions that saturate in both directions. Efficient computation: Only comparison, addition and multiplication. Scale-invariant: max ( 0 , a x ) = a max ( 0 , x ) for a ≥ 0 {\displaystyle \max(0,ax)=a\max(0,x){\text{ for }}a\geq 0} .Rectifying activation functions were used to separate specific excitation and unspecific inhibition in the neural abstraction pyramid, which was trained in a supervised way to learn several computer vision tasks. In 2011, the use of the rectifier as a non-linearity has been shown to enable training deep supervised neural networks without requiring unsupervised pre-training. Rectified linear units, compared to sigmoid function or similar activation functions, allow faster and effective training of deep neural architectures on large and complex datasets.
Data (computer science) Peripheral storage Data_(computer_science) > Data keys and values, structures and persistence > Peripheral storage In those systems, the files could be filled up, running out of data space before all the data had been written to them. Thus much unused data space was reserved unproductively to ensure adequate free space for each file. Later file-systems introduced partitions.

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