page_content
stringlengths 51
3.15k
|
|---|
Adjuvant therapy Dose-dense chemotherapy Adjuvant_therapy > Adjuvant cancer therapy > Dose-dense chemotherapy This practice has led scientists to the hypothesis that the recurrence of cancer after surgery and chemo may be due to the rapidly diving cells outpacing the rate of chemotherapy administration. DDC tries to circumvent this issue by giving chemotherapy every 2 weeks. To lessen the side effects of chemotherapy that can be exacerbated with more closely administered chemotherapy treatments, growth factors are typically given in conjunction with DDC to restore white blood cell counts. A recent 2018 meta-analysis of DDC clinical trials in early stage breast cancer patients indicated promising results in premenopausal women, but DDC has yet to become the standard of treatment in clinics.
|
Hashed array tree Definitions Hashed_array_tree > Definitions As defined by Sitarski, a hashed array tree has a top-level directory containing a power of two number of leaf arrays. All leaf arrays are the same size as the top-level directory. This structure superficially resembles a hash table with array-based collision chains, which is the basis for the name hashed array tree. A full hashed array tree can hold m2 elements, where m is the size of the top-level directory. The use of powers of two enables faster physical addressing through bit operations instead of arithmetic operations of quotient and remainder and ensures the O(1) amortized performance of append operation in the presence of occasional global array copy while expanding.
|
Neuromyelitis optica spectrum disorder Signs and symptoms Neuromyelitis_optica_spectrum_disorder > Signs and symptoms The signs and symptoms of NMOSD depend on the neurologic structures the disease affects, and, to some extent, the antibodies involved. Signs and symptoms usually follow a relapsing and remitting course, but occasionally can be progressive (monophasic). Deficits can be temporary or permanent, the latter especially in the absence of treatment.The most common initial manifestation of the disease is inflammation of the spinal cord (myelitis). Myelitis causes spinal cord dysfunction, which can result in muscle weakness, paralysis in the limbs, lost or reduced sensation, spasms, loss of bladder and bowel control, or erectile dysfunction.
|
Glossary of string theory H Glossary_of_string_theory > H h 1. The weight of a field (for example, its eigenvalue for L0). 2. Hermitian; for example, h.c.
|
RNA Interference RNAi pathway for gene knockdown RNA_Interference > Applications > RNAi pathway for gene knockdown The RNAi cascade begins once the Dicer enzyme starts to process siRNA. The end result of the process leads to degradation of mRNA and destroys any instructions needed to build certain proteins. Using this method, researchers are able to decrease (but not completely eliminate) the expression of a targeted gene. Studying the effects of this decrease in expression may show the physiological role or impact of the targeted gene products.
|
TinyOS Implementation TinyOS > Implementation To enable the native compiler to better optimize across call boundaries, TinyOS uses nesC's features to link these callbacks, called events, statically. While being non-blocking enables TinyOS to maintain high concurrency with one stack, it forces programmers to write complex logic by stitching together many small event handlers. To support larger computations, TinyOS provides tasks, which are similar to a Deferred Procedure Call and interrupt handler bottom halves.
|
Quantum finite automaton Relation to quantum computing Metric_automata > Relation to quantum computing As of 2019, most quantum computers are implementations of measure-once quantum finite automata, and the software systems for programming them expose the state-preparation of | ψ ⟩ {\displaystyle |\psi \rangle } , measurement P {\displaystyle P} and a choice of unitary transformations U α {\displaystyle U_{\alpha }} , such the controlled NOT gate, the Hadamard transform and other quantum logic gates, directly to the programmer. The primary difference between real-world quantum computers and the theoretical framework presented above is that the initial state preparation cannot ever result in a point-like pure state, nor can the unitary operators be precisely applied. Thus, the initial state must be taken as a mixed state ρ = ∫ p ( x ) | ψ x ⟩ d x {\displaystyle \rho =\int p(x)|\psi _{x}\rangle dx} for some probability distribution p ( x ) {\displaystyle p(x)} characterizing the ability of the machinery to prepare an initial state close to the desired initial pure state | ψ ⟩ {\displaystyle |\psi \rangle } . This state is not stable, but suffers from some amount of quantum decoherence over time.
|
Feature (computer vision) Detection Interest_point_detection > Detection Feature detection includes methods for computing abstractions of image information and making local decisions at every image point whether there is an image feature of a given type at that point or not. The resulting features will be subsets of the image domain, often in the form of isolated points, continuous curves or connected regions. The extraction of features are sometimes made over several scalings. One of these methods is the scale-invariant feature transform (SIFT).
|
Renormalization Renormalizability Renormalization > Renormalizability Nonrenormalizable interactions in effective field theories rapidly become weaker as the energy scale becomes much smaller than the cutoff. The classic example is the Fermi theory of the weak nuclear force, a nonrenormalizable effective theory whose cutoff is comparable to the mass of the W particle. This fact may also provide a possible explanation for why almost all of the particle interactions we see are describable by renormalizable theories. It may be that any others that may exist at the GUT or Planck scale simply become too weak to detect in the realm we can observe, with one exception: gravity, whose exceedingly weak interaction is magnified by the presence of the enormous masses of stars and planets.
|
Fermi-Hubbard model Narrow energy band theory Fermi-Hubbard_model > Narrow energy band theory The width of the bands depends upon the value of the hopping integral. The Hubbard model introduces a contact interaction between particles of opposite spin on each site of the lattice. When the Hubbard model is used to describe electron systems, these interactions are expected to be repulsive, stemming from the screened Coulomb interaction.
|
Taylor's law Related analyses Taylor's_law > Related analyses It is considered to be good practice to estimate at least one additional analysis of aggregation (other than Taylor's law) because the use of only a single index may be misleading. Although a number of other methods for detecting relationships between the variance and mean in biological samples have been proposed, to date none have achieved the popularity of Taylor's law. The most popular analysis used in conjunction with Taylor's law is probably Iwao's Patchiness regression test but all the methods listed here have been used in the literature.
|
Belegost Plot Belegost > Plot The game is a manifestation of the motifs of JRR Tolkien's novels; the title comes from one of the underground dwarf towns in The Lord of the Rings, which is also where the game is set. Within the narrative, the town has been plundered by the Orcs, while the Alqualamir stone remained in the city. The task of the player is to find the stone and escape the city.
|
Multifactor design of experiments software Use of software Multifactor_design_of_experiments_software > Use of software Factorial experimental design software drastically simplifies previously laborious hand calculations needed before the use of computers. During World War II, a more sophisticated form of DOE, called factorial design, became a big weapon for speeding up industrial development for the Allied forces. These designs can be quite compact, involving as few as two levels of each factor and only a fraction of all the combinations, and yet they are quite powerful for screening purposes. After the war, a statistician at Imperial Chemical, George Box, described how to generate response surfaces for process optimization.
|
Recursive definition Summary Inductive_definition In mathematics and computer science, a recursive definition, or inductive definition, is used to define the elements in a set in terms of other elements in the set (Aczel 1977:740ff). Some examples of recursively-definable objects include factorials, natural numbers, Fibonacci numbers, and the Cantor ternary set. A recursive definition of a function defines values of the function for some inputs in terms of the values of the same function for other (usually smaller) inputs. For example, the factorial function n!
|
Nondeterministic Finite Automaton Extended transition function Nondeterministic_Finite_Automaton > NFA with ε-moves > Extended transition function The automaton is said to accept a string w {\displaystyle w} if δ ∗ ( q 0 , w ) ∩ F ≠ ∅ , {\displaystyle \delta ^{*}(q_{0},w)\cap F\neq \emptyset ,} that is, if reading w {\displaystyle w} may drive the automaton from its start state q 0 {\displaystyle q_{0}} to some accepting state in F . {\displaystyle F. }: 25
|
Function-Behaviour-Structure ontology Summary Function-Behaviour-Structure_ontology The Function-Behaviour-Structure ontology – or short, the FBS ontology – is an ontology of design objects, i.e. things that have been or can be designed. The Function-Behaviour-Structure ontology conceptualizes design objects in three ontological categories: function (F), behaviour (B), and structure (S). The FBS ontology has been used in design science as a basis for modelling the process of designing as a set of distinct activities. This article relates to the concepts and models proposed by John S. Gero and his collaborators. Similar ideas have been developed independently by other researchers.
|
Cryptographic primitive Commonly used primitives Cryptographic_primitive > Commonly used primitives One-way hash function, sometimes also called as one-way compression function—compute a reduced hash value for a message (e.g., SHA-256) Symmetric key cryptography—compute a ciphertext decodable with the same key used to encode (e.g., AES) Public-key cryptography—compute a ciphertext decodable with a different key used to encode (e.g., RSA) Digital signatures—confirm the author of a message Mix network—pool communications from many users to anonymize what came from whom Private information retrieval—get database information without server knowing which item was requested Commitment scheme—allows one to commit to a chosen value while keeping it hidden to others, with the ability to reveal it later Cryptographically secure pseudorandom number generator
|
Short-time Fourier transform Inverse STFT Short-time_Fourier_transform > Inverse STFT The STFT is invertible, that is, the original signal can be recovered from the transform by the inverse STFT. The most widely accepted way of inverting the STFT is by using the overlap-add (OLA) method, which also allows for modifications to the STFT complex spectrum. This makes for a versatile signal processing method, referred to as the overlap and add with modifications method.
|
Nylon 4 Structure Flexible_plastic > Structure The backbone is the part of the chain that is on the main path, linking together a large number of repeat units. To customize the properties of a plastic, different molecular groups called side chains hang from this backbone; they are usually hung from the monomers before the monomers themselves are linked together to form the polymer chain. The structure of these side chains influences the properties of the polymer.
|
Snubber capacitor AC voltage and current Snubber_capacitor > Electrical characteristics > Voltage ratings > AC voltage and current The maximum RMS alternating voltage at a given frequency which may be applied continuously to a capacitor (up to the rated temperature) is defined as the rated AC voltage UR AC. Rated AC voltages usually are specified at the mains frequency of a region (50 or 60 Hz). The rated AC voltage is generally calculated so that an internal temperature rise of 8 to 10 K sets the allowed limit for film capacitors.
|
GoldSim Modeling Environment GoldSim > Modeling Environment GoldSim provides a visual and hierarchical modeling environment, which allows users to construct models by adding “elements” (model objects) that represent data, equations, processes or events, and linking them together into graphical representations that resemble influence diagrams. Influence arrows are automatically drawn as elements are referenced by other elements. Complex systems can be translated into hierarchical GoldSim models by creating layer of “containers” (or sub-models).
|
Digital marketing system Supervision and administration Digital_marketing_system > Privacy issues > Supervision and administration Customers should be informed that how will their data be used, what will be the effects and other relevant information in a concise, easy-to-understand and freeway so that they can determine whether it is necessary to grant authorization or not. Except the right to be informed, the GDPR also provide customers with seven other rights such as the right of access, the right to erasure, the right to restrict processing, the right to object and establishes corresponding accountability system. == References ==
|
Emil Artin Selected bibliography Emil_Artin > Selected bibliography viii+194, ISBN 978-0-8218-4426-7, MR 2467155 Artin, Emil (2007), Rosen, Michael (ed. ), Exposition by Emil Artin: a selection., History of Mathematics, vol. 30, Providence, RI: American Mathematical Society, ISBN 978-0-8218-4172-3, MR 2288274 Reprints Artin's books on the gamma function, Galois theory, the theory of algebraic numbers, and several of his papers.
|
Rigid body kinetics Generalized forces Rigid_body_kinetics > Virtual work of forces acting on a rigid body > Generalized forces For simplicity consider a trajectory of a rigid body that is specified by a single generalized coordinate q, such as a rotation angle, then the formula becomes Introduce the resultant force F and torque T so this equation takes the form The quantity Q defined by is known as the generalized force associated with the virtual displacement δq. This formula generalizes to the movement of a rigid body defined by more than one generalized coordinate, that is where It is useful to note that conservative forces such as gravity and spring forces are derivable from a potential function V(q1, ..., qn), known as a potential energy. In this case the generalized forces are given by
|
Energy return on investment ESOEI Energy_return_on_investment > ESOEI ESOEI (or ESOIe) is used when EROI is below 1. "ESOIe is the ratio of electrical energy stored over the lifetime of a storage device to the amount of embodied electrical energy required to build the device." One of the notable outcomes of the Stanford University team's assessment on ESOI, was that if pumped storage was not available, the combination of wind energy and the commonly suggested pairing with battery technology as it presently exists, would not be sufficiently worth the investment, suggesting instead curtailment.
|
Multisystem inflammatory syndrome in children Characteristics Multisystem_inflammatory_syndrome_in_children > Characteristics MIS-C / PIMS-TS is a systemic disorder involving persistent fever, extreme inflammation (hyperinflammation), and organ dysfunction, which is temporally associated with exposure to COVID-19. Onset may be delayed or contemporary with ongoing SARS-CoV-2 infection, which may pass without symptoms. The time the syndrome takes to appear following the initial viral infection is debated, though it may develop between the first and second week. Epidemiological data suggest that recognition of the disease may typically be delayed by 2–6 weeks, and usually by 3–4 weeks.
|
Biquadratic function Ferrari's solution Fourth-degree_equation > Solution > Solution methods > Ferrari's solution {\displaystyle \left(y^{2}+{\frac {p}{2}}\right)^{2}=-qy-r+{\frac {p^{2}}{4}}.} Then, we introduce a variable m into the factor on the left-hand side by adding 2y2m + pm + m2 to both sides. After regrouping the coefficients of the power of y on the right-hand side, this gives the equation which is equivalent to the original equation, whichever value is given to m. As the value of m may be arbitrarily chosen, we will choose it in order to complete the square on the right-hand side.
|
Multi-scale signal analysis Typical devices Signal_Processing > Typical devices Filters – for example analog (passive or active) or digital (FIR, IIR, frequency domain or stochastic filters, etc.) Samplers and analog-to-digital converters for signal acquisition and reconstruction, which involves measuring a physical signal, storing or transferring it as digital signal, and possibly later rebuilding the original signal or an approximation thereof. Signal compressors Digital signal processors (DSPs)
|
Linear Discriminant Analysis LDA for two classes Fisher's_linear_discriminant > LDA for two classes It is often useful to see this conclusion in geometrical terms: the criterion of an input x → {\displaystyle {\vec {x}}} being in a class y {\displaystyle y} is purely a function of projection of multidimensional-space point x → {\displaystyle {\vec {x}}} onto vector w → {\displaystyle {\vec {w}}} (thus, we only consider its direction). In other words, the observation belongs to y {\displaystyle y} if corresponding x → {\displaystyle {\vec {x}}} is located on a certain side of a hyperplane perpendicular to w → {\displaystyle {\vec {w}}} . The location of the plane is defined by the threshold c {\displaystyle c} .
|
Generalization error Relation to overfitting Generalization_error > Relation to overfitting The concepts of generalization error and overfitting are closely related. Overfitting occurs when the learned function f S {\displaystyle f_{S}} becomes sensitive to the noise in the sample. As a result, the function will perform well on the training set but not perform well on other data from the joint probability distribution of x {\displaystyle x} and y {\displaystyle y} . Thus, the more overfitting occurs, the larger the generalization error.
|
Polymer chain Degradation Polymer_main_chain > Degradation When heated above 450 °C, polyethylene degrades to form a mixture of hydrocarbons. In the case of chain-end scission, monomers are released and this process is referred to as unzipping or depolymerization. Which mechanism dominates will depend on the type of polymer and temperature; in general, polymers with no or a single small substituent in the repeat unit will decompose via random-chain scission. The sorting of polymer waste for recycling purposes may be facilitated by the use of the resin identification codes developed by the Society of the Plastics Industry to identify the type of plastic.
|
ZFS Data integrity ZFS > Features > Data integrity Within ZFS, data integrity is achieved by using a Fletcher-based checksum or a SHA-256 hash throughout the file system tree. Each block of data is checksummed and the checksum value is then saved in the pointer to that block—rather than at the actual block itself. Next, the block pointer is checksummed, with the value being saved at its pointer.
|
Outline of computer science Scientific computing Outline_of_computer_science > Subfields > Scientific computing Computational science – constructing mathematical models and quantitative analysis techniques and using computers to analyze and solve scientific problems. Numerical analysis – Approximate numerical solution of mathematical problems such as root-finding, integration, the solution of ordinary differential equations; the approximation of special functions. Symbolic computation – Manipulation and solution of expressions in symbolic form, also known as Computer algebra. Computational physics – Numerical simulations of large non-analytic systems Computational chemistry – Computational modelling of theoretical chemistry in order to determine chemical structures and properties Bioinformatics and Computational biology – The use of computer science to maintain, analyse, store biological data and to assist in solving biological problems such as Protein folding, function prediction and Phylogeny. Computational neuroscience – Computational modelling of neurophysiology. Computational Linguistics Computational logic Computational engineering
|
Communication privacy management theory Private boundaries Communication_privacy_management_theory > Theory elements > Private boundaries An individual's private information is protected by their boundaries. The permeability of these boundaries are ever-changing. Boundaries can be relatively permeable (easy to cross) or relatively impregnable (rigid and difficult to cross).
|
Optimality model Construction Optimality_model > Construction Optimality is defined as the point where the difference between benefits and costs for a behavior is maximized, which can be done by graphing the benefits and costs on the y-axis and a measure of the behavior on the x-axis. A currency must also be identified.
|
Debt-to-income ratio Conforming loans Debt-to-income_ratio > DTI limits used in qualifying borrowers > United States > Conforming loans In the United States, for conforming loans, the following limits are currently typical: Conventional financing limits are typically 28/36 for manually underwritten loans. The maximum can be exceeded up to 45% if the borrower meets additional credit score and reserve requirements. FHA limits are currently 31/43.
|
Fanconi anemia Treatment Fanconi_anaemia > Treatment The first line of therapy is androgens and hematopoietic growth factors, but only 50–75% of patients respond. A more permanent cure is hematopoietic stem cell transplantation. If no potential donors exist, a savior sibling can be conceived by preimplantation genetic diagnosis (PGD) to match the recipient's HLA type.
|
TCP connection Dupack-based retransmission TCP_header > Protocol operation > Data transfer > Reliable transmission > Dupack-based retransmission If a single segment (say segment number 100) in a stream is lost, then the receiver cannot acknowledge packets above that segment number (100) because it uses cumulative ACKs. Hence the receiver acknowledges packet 99 again on the receipt of another data packet. This duplicate acknowledgement is used as a signal for packet loss. That is, if the sender receives three duplicate acknowledgements, it retransmits the last unacknowledged packet.
|
Factoring problem Difficulty and complexity Factor_table > Current state of the art > Difficulty and complexity An answer of "yes" can be certified by exhibiting a factorization n = d(n/d) with d ≤ k. An answer of "no" can be certified by exhibiting the factorization of n into distinct primes, all larger than k; one can verify their primality using the AKS primality test, and then multiply them to obtain n. The fundamental theorem of arithmetic guarantees that there is only one possible string of increasing primes that will be accepted, which shows that the problem is in both UP and co-UP. It is known to be in BQP because of Shor's algorithm. The problem is suspected to be outside all three of the complexity classes P, NP-complete, and co-NP-complete.
|
Origin and function of meiosis Prophase I arrest Origin_and_function_of_meiosis > Function > Prophase I arrest The arrest of ooctyes at the four genome copy stage was proposed to provide the informational redundancy needed to repair damage in the DNA of the germline. The repair process used likely involves homologous recombinational repair. Prophase arrested oocytes have a high capability for efficient repair of DNA damages. The adaptive function of the DNA repair capability during meiosis appears to be a key quality control mechanism in the female germ line and a critical determinant of fertility.
|
Lombard effect Private loop Lombard_effect > Mechanisms > Private loop A speaker can regulate their vocalizations, particularly their amplitude relative to background noise, with reflexive auditory feedback. Such auditory feedback is known to maintain the production of vocalization since deafness affects the vocal acoustics of both humans and songbirds Changing the auditory feedback also changes vocalization in human speech or bird song. Neural circuits have been found in the brainstem that enable such reflex adjustment.
|
Acoustic sensor Structural Vibration and Dynamics Acoustic_sensor > Subdisciplines > Structural Vibration and Dynamics Structural acoustics is the study of motions and interactions of mechanical systems with their environments and the methods of their measurement, analysis, and control . There are several sub-disciplines found within this regime: Modal Analysis Material characterization Structural health monitoring Acoustic Metamaterials Friction AcousticsApplications might include: ground vibrations from railways; vibration isolation to reduce vibration in operating theatres; studying how vibration can damage health (vibration white finger); vibration control to protect a building from earthquakes, or measuring how structure-borne sound moves through buildings.
|
Privacy seal Origin Privacy_seal > Origin This information can be sold to third-parties for advertising purposes or be used by the company for data profiling purposes. Companies can price discriminate by using the information collected to predict the highest price point a customer is willing to pay.Except for Federal Trade Commission guidelines, first established in a 1999 report, privacy protection is mainly self-regulated in the United States. Self regulators argue that governmental intervention would harm e-commerce because its inflexibility does not allow for each company to experiment with their policies and disclosures.
|
Epinephrine (medication) Mechanism of action Epinephrine_(medication) > Mechanism of action Together, these effects increase blood glucose and fatty acids, providing substrates for energy production within cells throughout the body. In the heart, the coronary arteries have a predominance of β2 receptors, which cause vasodilation of the coronary arteries in the presence of epinephrine.Its actions increase peripheral resistance via α1 receptor-dependent vasoconstriction and increase cardiac output via its binding to β1 receptors. The goal of reducing peripheral circulation is to increase coronary and cerebral perfusion pressures and therefore increase oxygen exchange at the cellular level. While epinephrine does increase aortic, cerebral, and carotid circulation pressure, it lowers carotid blood flow and end-tidal CO2 or ETCO2 levels. It appears that epinephrine may improve macrocirculation at the expense of the capillary beds where perfusion takes place.
|
Labor theory of value Labor process Labor_theory_of_value > Labor process Since the term "value" is understood in the LTV as denoting something created by labor, and its "magnitude" as something proportional to the quantity of labor performed, it is important to explain how the labor process both preserves value and adds new value in the commodities it creates.The value of a commodity increases in proportion to the duration and intensity of labor performed on average for its production. Part of what the LTV means by "socially necessary" is that the value only increases in proportion to this labor as it is performed with average skill and average productivity. So though workers may labor with greater skill or more productivity than others, these more skillful and more productive workers thus produce more value through the production of greater quantities of the finished commodity. Each unit still bears the same value as all the others of the same class of commodity.
|
Earthquake prediction VAN seismic electric signals Earthquake_prediction > Prediction methods > Precursors > Electromagnetic anomalies > VAN seismic electric signals Additional criticism was raised the same year in a public debate between some of the principals.A primary criticism was that the method is geophysically implausible and scientifically unsound. Additional objections included the demonstrable falsity of the claimed one-to-one relationship of earthquakes and SES, the unlikelihood of a precursory process generating signals stronger than any observed from the actual earthquakes, and the very strong likelihood that the signals were man-made. Further work in Greece has tracked SES-like "anomalous transient electric signals" back to specific human sources, and found that such signals are not excluded by the criteria used by VAN to identify SES.
|
Racetrack principle Proof Racetrack_principle > Proof Combining these observations, we can use the mean value theorem on the interval {\displaystyle } and get 0 < h ′ ( x 0 ) = h ( x ) − h ( 0 ) x − 0 = f ( x ) − g ( x ) x . {\displaystyle 0 0 {\displaystyle x>0} , so multiplying both sides by x {\displaystyle x} gives f ( x ) − g ( x ) > 0 {\displaystyle f(x)-g(x)>0} . This implies f ( x ) > g ( x ) {\displaystyle f(x)>g(x)} .
|
Welding machine Transformer Welding_machine > Power supply designs > Transformer A transformer-style welding power supply converts the moderate voltage and moderate current electricity from the utility mains (typically 230 or 115 VAC) into a high current and low voltage supply, typically between 17 and 45 (open-circuit) volts and 55 to 590 amperes. A rectifier converts the AC into DC on more expensive machines. This design typically allows the welder to select the output current by variously moving a primary winding closer or farther from a secondary winding, moving a magnetic shunt in and out of the core of the transformer, using a series saturating reactor with a variable saturating technique in series with the secondary current output, or by simply permitting the welder to select the output voltage from a set of taps on the transformer's secondary winding.
|
Green algal derived chloroplast Specialized chloroplasts in C4 plants Chloroplast > Structure > Specialized chloroplasts in C4 plants They store CO2 in a four-carbon compound, which is why the process is called C4 photosynthesis. The four-carbon compound is then transported to the bundle sheath chloroplasts, where it drops off CO2 and returns to the mesophyll. Bundle sheath chloroplasts do not carry out the light reactions, preventing oxygen from building up in them and disrupting RuBisCO activity.
|
Real power Active, reactive, apparent, and complex power in sinusoidal steady-state AC_power > Active, reactive, apparent, and complex power in sinusoidal steady-state If a capacitor and an inductor are placed in parallel, then the currents flowing through the capacitor and the inductor tend to cancel rather than add. This is the fundamental mechanism for controlling the power factor in electric power transmission; capacitors (or inductors) are inserted in a circuit to partially compensate for reactive power 'consumed' ('generated') by the load. Purely capacitive circuits supply reactive power with the current waveform leading the voltage waveform by 90 degrees, while purely inductive circuits absorb reactive power with the current waveform lagging the voltage waveform by 90 degrees.
|
Photoinduced charge separation Rutherford model Photoinduced_charge_separation > Rutherford model An atom consists of a positively-charged nucleus surrounded by bound electrons. The nucleus consists of uncharged neutrons and positively charged protons. Electrons are negatively charged.
|
Predation Population dynamics Predation > Role in ecosystems > Population dynamics The snowshoe hare-lynx system is subarctic, but even this involves other predators, including coyotes, goshawks and great horned owls, and the cycle is reinforced by variations in the food available to the hares.A range of mathematical models have been developed by relaxing the assumptions made in the Lotka–Volterra model; these variously allow animals to have geographic distributions, or to migrate; to have differences between individuals, such as sexes and an age structure, so that only some individuals reproduce; to live in a varying environment, such as with changing seasons; and analysing the interactions of more than just two species at once. Such models predict widely differing and often chaotic predator-prey population dynamics. The presence of refuge areas, where prey are safe from predators, may enable prey to maintain larger populations but may also destabilize the dynamics.
|
Extended real Limits Negative_infinity > Motivation > Limits It is often useful to describe the behavior of a function f {\displaystyle f} as either the argument x {\displaystyle x} or the function value f {\displaystyle f} gets "infinitely large" in some sense. For example, consider the function f {\displaystyle f} defined by f ( x ) = 1 x 2 . {\displaystyle f(x)={\frac {1}{x^{2}}}.}
|
Data vault modeling History and philosophy Data_vault_modeling > History and philosophy The determination of data being "wrong" is an interpretation of the data that stems from a particular point of view that may not be valid for everyone, or at every point in time. Therefore the data vault must capture all data and only when reporting or extracting data from the data vault is the data being interpreted. Another issue to which data vault is a response is that more and more there is a need for complete auditability and traceability of all the data in the data warehouse.
|
Beta distribution Summary Beta_distribution In probability theory and statistics, the beta distribution is a family of continuous probability distributions defined on the interval or (0, 1) in terms of two positive parameters, denoted by alpha (α) and beta (β), that appear as exponents of the variable and its complement to 1, respectively, and control the shape of the distribution. The beta distribution has been applied to model the behavior of random variables limited to intervals of finite length in a wide variety of disciplines. The beta distribution is a suitable model for the random behavior of percentages and proportions.
|
Unit of volume Units Units_of_volume > Units According to the SI system, the base unit for measuring length is the metre. The SI unit of volume is thus the cubic metre, which is a derived unit, where:1 m3 = 1 m • 1 m • 1 m.
|
Homogeneous model Summary Homogeneous_model The applications of model theory to algebraic and Diophantine geometry reflect this proximity to classical mathematics, as they often involve an integration of algebraic and model-theoretic results and techniques. Consequently, proof theory is syntactic in nature, in contrast to model theory, which is semantic in nature. The most prominent scholarly organization in the field of model theory is the Association for Symbolic Logic.
|
Weight distribution Summary Weight_distribution Weight distribution is the apportioning of weight within a vehicle, especially cars, airplanes, and trains. Typically, it is written in the form x/y, where x is the percentage of weight in the front, and y is the percentage in the back. In a vehicle which relies on gravity in some way, weight distribution directly affects a variety of vehicle characteristics, including handling, acceleration, traction, and component life. For this reason weight distribution varies with the vehicle's intended usage.
|
Product-moment correlation coefficient In least squares regression analysis Pearson_coefficient > In least squares regression analysis The square of the sample correlation coefficient is typically denoted r2 and is a special case of the coefficient of determination. In this case, it estimates the fraction of the variance in Y that is explained by X in a simple linear regression. So if we have the observed dataset Y 1 , … , Y n {\displaystyle Y_{1},\dots ,Y_{n}} and the fitted dataset Y ^ 1 , … , Y ^ n {\displaystyle {\hat {Y}}_{1},\dots ,{\hat {Y}}_{n}} then as a starting point the total variation in the Yi around their average value can be decomposed as follows ∑ i ( Y i − Y ¯ ) 2 = ∑ i ( Y i − Y ^ i ) 2 + ∑ i ( Y ^ i − Y ¯ ) 2 , {\displaystyle \sum _{i}(Y_{i}-{\bar {Y}})^{2}=\sum _{i}(Y_{i}-{\hat {Y}}_{i})^{2}+\sum _{i}({\hat {Y}}_{i}-{\bar {Y}})^{2},} where the Y ^ i {\displaystyle {\hat {Y}}_{i}} are the fitted values from the regression analysis. This can be rearranged to give 1 = ∑ i ( Y i − Y ^ i ) 2 ∑ i ( Y i − Y ¯ ) 2 + ∑ i ( Y ^ i − Y ¯ ) 2 ∑ i ( Y i − Y ¯ ) 2 .
|
Nitric-oxide reductase Mechanism Nitric-oxide_reductase > Mechanism The Glu groups provide an electron-negative charge to the active site. The electro-negative charge reduces the reaction potential for heme b3 and allows NO to bind to the binuclear activation site. Glu residues also provide protons needed for removal of N2O and production of H2O.
|
Global data-flow analysis Ordering Flow_analysis > An iterative algorithm > Ordering Postorder - This is a typical iteration order for backward data-flow problems. In postorder iteration, a node is visited after all its successor nodes have been visited. Typically, the postorder iteration is implemented with the depth-first strategy.
|
P orbitals Hydrogen-like orbitals 1s_electron > Hydrogen-like orbitals The rules restricting the values of the quantum numbers, and their energies (see below), explain the electron configuration of the atoms and the periodic table. The stationary states (quantum states) of the hydrogen-like atoms are its atomic orbitals. However, in general, an electron's behavior is not fully described by a single orbital.
|
Elementary row operation Summary Elementary_row_operations In mathematics, an elementary matrix is a matrix which differs from the identity matrix by one single elementary row operation. The elementary matrices generate the general linear group GLn(F) when F is a field. Left multiplication (pre-multiplication) by an elementary matrix represents elementary row operations, while right multiplication (post-multiplication) represents elementary column operations. Elementary row operations are used in Gaussian elimination to reduce a matrix to row echelon form. They are also used in Gauss–Jordan elimination to further reduce the matrix to reduced row echelon form.
|
Bile salt hydrolase Immunity Bile_salt_hydrolase > Effects on human physiology and immunity > Immunity Secondary bile acids can influence innate immunity through their interactions with the bile acid receptors mentioned above, FXR and TGR-5. FXR and TGR-5 are expressed by intestinal immune cells such as macrophages, as well as NKT cells and dendritic cells. FXR has been shown to play a role with TLR-9 in inhibiting inflammation.
|
Glossary of functional analysis Summary Glossary_of_functional_analysis This is a glossary for the terminology in a mathematical field of functional analysis. Throughout the article, unless stated otherwise, the base field of a vector space is the field of real numbers or that of complex numbers. Algebras are not assumed to be unital. See also: List of Banach spaces.
|
Friction torque Engineering Friction_torque > Engineering Friction torque can also be an asset in engineering. Bolts and nuts, or screws are often designed to be fastened with a given amount of torque, where the friction is adequate during use or operation for the bolt, nut, or screw to remain safely fastened. This is true with such applications as lug nuts retaining wheels to vehicles, or equipment subjected to vibration with sufficiently well-attached bolts, nuts, or screws to prevent the vibration from shaking them loose.
|
Blockchain-based remittances company Economic benefits for developing countries Blockchain-based_remittances_company > Dynamics > Economic benefits for developing countries Thus, the remittances sent by migrants can potentially encourage domestic investment, ensuring economic growth. However, new findings for Armenia suggest that remittances help potential migrants to ease the migration process, serving as a resource rather than as a contractual tool between migrants and non-migrants. It is concluded that remittances drastically shift emigration intentions upward.
|
C symmetry Scalar fields C-symmetry > Scalar fields {\displaystyle {\mathsf {C}}\psi =\psi ^{*}.} The above describes the conventional construction of a charged scalar field.
|
Serine/arginine-rich splicing factor 1 Splicing Serine/arginine-rich_splicing_factor_1 > Splicing ASF/SF2 is an integral part of numerous components of the splicing process. ASF/SF2 is required for 5’ splice site cleavage and selection, and is capable of discriminating between cryptic and authentic splice sites. Subsequent lariat formation during the first chemical step of pre-mRNA splicing also requires ASF/SF2. ASF/SF2 promotes recruitment of the U1 snRNP to the 5’ splice site, and bridges the 5’ and 3’ splice sites to facilitate splicing reactions.
|
Satisfaction Equilibrium Summary Satisfaction_Equilibrium In game theory, a satisfaction equilibrium is a solution concept for a class of non-cooperative games, namely games in satisfaction form. Games in satisfaction form model situations in which players aim at satisfying a given individual constraint, e.g., a performance metric must be smaller or bigger than a given threshold. When a player satisfies its own constraint, the player is said to be satisfied. A satisfaction equilibrium, if it exists, arises when all players in the game are satisfied.
|
Pi-interaction Catalysis Pi_interaction > Metal–π interactions > Catalysis The use of organometallic structures led by π–metal bonding plays an enormous role in the catalysis of organic reactions. The Stille reaction is a widely known and important reaction in organic synthesis. π interactions with the Pd catalyst in this reaction are almost necessary in pushing this reaction to completion (alkyl groups transfer is rather slow). Other widely known reactions based on π–metal catalysis interactions are: Heck reaction Hiyama coupling Kumada coupling Negishi coupling Petasis reaction Sonogashira coupling Suzuki reaction.π–metal interactions can also be involved directly with the function of ligands on the catalyst.
|
Yeoman plotter Summary Yeoman_plotter The Yeoman Plotter was a plotter used on ships and boats to transfer GPS coordinates or RADAR echo locations onto a paper navigation chart and to read coordinates from the chart. It was manufactured from 1985 to 2014/2015 and was an intermediary step between traditional paper chart navigation and full electronic chart displays. It was easy to understand for people that were accustomed to paper charts and much cheaper than electronic chart displays available at the time. The continuing fall in prices of electronic chart displays, their increase in functionality such as radar overlay and the advent of cheap tablets eventually made the Yeoman plotter uncompetitive.
|
Fundamental physical constants External articles Dimensionless_physical_constant > External articles S2CID 8875571. John D. Barrow and Webb, J. K., "Inconstant Constants – Do the inner workings of nature change with time?" Scientific American (June 2005).
|
Functional Programming Efficiency issues Functional_program > Comparison to imperative programming > Efficiency issues Functional programming languages are typically less efficient in their use of CPU and memory than imperative languages such as C and Pascal. This is related to the fact that some mutable data structures like arrays have a very straightforward implementation using present hardware. Flat arrays may be accessed very efficiently with deeply pipelined CPUs, prefetched efficiently through caches (with no complex pointer chasing), or handled with SIMD instructions. It is also not easy to create their equally efficient general-purpose immutable counterparts.
|
Electric Eel Early research Electric_Eel > Interactions with humans > Early research The electric eels, having given many shocks, "now require long rest and plenty of nourishment to replace the loss of galvanic power they have suffered", "swam timidly to the bank of the pond", and were easily caught using small harpoons on ropes. Humboldt recorded that the people did not eat the electric organs, and that they feared the fish so much that they would not fish for them in the usual way.In 1839, the chemist Michael Faraday extensively tested the electrical properties of an electric eel imported from Surinam. For a span of four months, he measured the electrical impulses produced by the animal by pressing shaped copper paddles and saddles against the specimen.
|
Connexin-43 internal ribosome entry site (IRES) Function Connexin_43 > Function In the cytoplasm, the protein regulates the microtubule network and, by extension, cell migration and polarity. This function has been observed in brain and heart development, as well as wound-healing in endothelial cells. GJA1 has also been observed to localize to the mitochondria, where it promotes cell survival by downregulating the intrinsic apoptotic pathway during conditions of oxidative stress.
|
Single assignment Semantics Assignment_operation > Semantics Consequently, assignment is dependent on the concept of variables. In an assignment: The expression is evaluated in the current state of the program. The variable is assigned the computed value, replacing the prior value of that variable.Example: Assuming that a is a numeric variable, the assignment a := 2*a means that the content of the variable a is doubled after the execution of the statement.
|
Antimicrobial pharmacodynamics Post-antibiotic effect Antimicrobial_pharmacodynamics > Post-antibiotic effect Most antimicrobials possess significant in vitro PAEs (≥ 1.5 hours) against susceptible gram-positive cocci. Antimicrobials with significant PAEs against susceptible gram-negative bacilli are limited to carbapenems and agents that inhibit protein or DNA synthesis. == References ==
|
Introduction to gauge theory An example of a symmetry in a physical theory: translation invariance Introduction_to_gauge_theory > In classical physics > General relativity > An example of a symmetry in a physical theory: translation invariance Some global symmetries under changes of coordinate predate both general relativity and the concept of a gauge. For example, Galileo and Newton introduced the notion of translation invariance, an advancement from the Aristotelian concept that different places in space, such as the earth versus the heavens, obeyed different physical rules. Suppose, for example, that one observer examines the properties of a hydrogen atom on Earth, the other—on the Moon (or any other place in the universe), the observer will find that their hydrogen atoms exhibit completely identical properties. Again, if one observer had examined a hydrogen atom today and the other—100 years ago (or any other time in the past or in the future), the two experiments would again produce completely identical results.
|
Secret sharing Importance Secret_splitting > Importance Thus a key can be distributed over many servers by a threshold secret sharing mechanism. The key is then reconstructed when needed. Secret sharing has also been suggested for sensor networks where the links are liable to be tapped, by sending the data in shares which makes the task of the eavesdropper harder. The security in such environments can be made greater by continuous changing of the way the shares are constructed.
|
Liver protein production Biliary flow Hepatic_metabolism > Functions > Biliary flow The cystic duct from the gallbladder joins with the common hepatic duct to form the common bile duct. The biliary system and connective tissue is supplied by the hepatic artery alone. Bile either drains directly into the duodenum via the common bile duct, or is temporarily stored in the gallbladder via the cystic duct. The common bile duct and the pancreatic duct enter the second part of the duodenum together at the hepatopancreatic ampulla, also known as the ampulla of Vater.
|
Antigen presenting cells Non-professional APCs Antigen-presenting_cells > Types and functions > Non-professional APCs Non-professional antigen presenting cells include all nucleated cell types in the body. They use an MHC class I molecule coupled to beta-2 microglobulin to display endogenous peptides on the cell membrane. These peptides originate within the cell itself, in contrast to the exogenous antigen displayed by professional APCs using MHC class II molecules. Cytotoxic T cells are able to interact with endogenous antigen presented using an MHC class I molecule.
|
Neutralizing antibody Production Neutralizing_antibody > Production Once a B cell is fully activated, it rapidly proliferates and differentiates into plasma cells. Plasma cells then secrete the antigen-specific antibody in large quantities. After a first encounter of the antigen by vaccination or natural infection, immunological memory allows for a more rapid production of neutralizing antibodies following the next exposure to the virus.
|
Joseph-Louis Lagrange Fundamental treatise Joseph-Louis_Lagrange > Work in Berlin > Fundamental treatise Instead of following the motion of each individual part of a material system, as D'Alembert and Euler had done, he showed that, if we determine its configuration by a sufficient number of variables x, called generalized coordinates, whose number is the same as that of the degrees of freedom possessed by the system, then the kinetic and potential energies of the system can be expressed in terms of those variables, and the differential equations of motion thence deduced by simple differentiation. For example, in dynamics of a rigid system he replaces the consideration of the particular problem by the general equation, which is now usually written in the form d d t ∂ T ∂ x ˙ − ∂ T ∂ x + ∂ V ∂ x = 0 , {\displaystyle {\frac {d}{dt}}{\frac {\partial T}{\partial {\dot {x}}}}-{\frac {\partial T}{\partial x}}+{\frac {\partial V}{\partial x}}=0,} where T represents the kinetic energy and V represents the potential energy of the system.
|
Biology of depression Reward Biology_of_depression > Emotional processing and neural circuits > Reward While a number of studies suggest that depressed subjects rate positive stimuli less positively and as less arousing, a number of studies fail to find a difference. Furthermore, response to natural rewards such as sucrose does not appear to be attenuated. General affective blunting may explain "anhedonic" symptoms in depression, as meta analysis of both positive and negative stimuli reveal reduced rating of intensity.
|
Matrix decoder Electro-Voice Stereo-4 matrix (2:2:4) / (4:2:4) Matrix_decoder > Electro-Voice Stereo-4 matrix (2:2:4) / (4:2:4) The Stereo-4 matrix was invented by Leonard Feldman and Jon Fixler, introduced in 1970, and sold by Electro-Voice and Radio Shack. This matrix was used to encode 4 sound channels on many record albums (4:2:4).
|
Immunologic adjuvant Humans Immunologic_adjuvant > Medical complications > Humans Vitamin E increases hypocretin-specific fragments that bind to DQB1*602 in cell culture experiments, leading to the hypothesis that autoimmunity may arise in genetically susceptible individuals, but there is no clinical data to support this hypothesis. The third AS03 ingredient is polysorbate 80. Polysorbate 80 is also found in both the Oxford–AstraZeneca and Janssen COVID-19 vaccines.
|
Specific heat capacity Imperial engineering units Specific_heat_capacity > Units > Imperial engineering units Professionals in construction, civil engineering, chemical engineering, and other technical disciplines, especially in the United States, may use English Engineering units including the pound (lb = 0.45359237 kg) as the unit of mass, the degree Fahrenheit or Rankine (°R = 5/9 K, about 0.555556 K) as the unit of temperature increment, and the British thermal unit (BTU ≈ 1055.056 J), as the unit of heat. In those contexts, the unit of specific heat capacity is BTU/lb⋅°R, or 1 BTU/lb⋅°R = 4186.68J/kg⋅K. The BTU was originally defined so that the average specific heat capacity of water would be 1 BTU/lb⋅°F. Note the value's similarity to that of the calorie - 4187 J/kg⋅°C ≈ 4184 J/kg⋅°C (~.07%) - as they are essentially measuring the same energy, using water as a basis reference, scaled to their systems' respective lbs and °F, or kg and °C.
|
Michael selection theorem A function that satisfies all requirements Michael_selection_theorem > Examples > A function that satisfies all requirements The function: F ( x ) = {\displaystyle F(x)=} , shown by the grey area in the figure at the right, is a set-valued function from the real interval to itself. It satisfies all Michael's conditions, and indeed it has a continuous selection, for example: f ( x ) = 1 − x / 2 {\displaystyle f(x)=1-x/2} or f ( x ) = 1 − 3 x / 8 {\displaystyle f(x)=1-3x/8} .
|
Automated refractor Technique Automated_refractor > Technique The majority of autorefractors calculate the vision correction a patient needs (refraction) by using sensors that detect the reflections from a cone of infrared light. These reflections are used to determine the size and shape of a ring in the retina which is located in the posterior part of the eye. By measuring this zone, the autorefractor can determine when a patient's eye properly focuses an image.
|
Lycoperdonosis Summary Lycoperdonosis Chest radiographs reveal the presence of lung nodules. The early symptoms presented in combination with pulmonary abnormalities apparent on chest radiographs may lead to misdiagnosis of the disease as tuberculosis, histiocytosis, or pneumonia caused by Pneumocystis carinii. Lycoperdonosis is generally treated with corticosteroids, which decrease the inflammatory response; these are sometimes given in conjunction with antimicrobials.The disease was first described in the medical literature in 1967 by R.D.
|
Artificial philosophy Conclusion Artificial_philosophy > Final Review and Considerations > Conclusion Superintelligence: Paths, Dangers, Strategies. Oxford University Press. This book discusses the potential future of artificial superintelligence and the ways it might be controlled.
|
Bayesian search theory Procedure Bayesian_search_theory > Procedure This gives the probability of finding the object by looking in location X, for all possible locations X. (This can be visualized as a contour map of probability.) Construct a search path which starts at the point of highest probability and 'scans' over high probability areas, then intermediate probabilities, and finally low probability areas.
|
Richter Scale Details Local_magnitude_scale > Details These short waves (high frequency waves) are too short a yardstick to measure the extent of the event. The resulting effective upper limit of measurement for ML is about 7 and about 8.5 for Ms .New techniques to avoid the saturation problem and to measure magnitudes rapidly for very large earthquakes are being developed. One of these is based on the long-period P-wave; the other is based on a recently discovered channel wave.The energy release of an earthquake, which closely correlates to its destructive power, scales with the 3⁄2 power of the shaking amplitude (see Moment magnitude scale for an explanation). Thus, a difference in magnitude of 1.0 is equivalent to a factor of 31.6 ( = ( 10 1.0 ) ( 3 / 2 ) {\displaystyle =({10^{1.0}})^{(3/2)}} ) in the energy released; a difference in magnitude of 2.0 is equivalent to a factor of 1000 ( = ( 10 2.0 ) ( 3 / 2 ) {\displaystyle =({10^{2.0}})^{(3/2)}} ) in the energy released. The elastic energy radiated is best derived from an integration of the radiated spectrum, but an estimate can be based on mb because most energy is carried by the high frequency waves.
|
Antipode (algebra) Examples Hopf_algebras > Examples Note that functions on a finite group can be identified with the group ring, though these are more naturally thought of as dual – the group ring consists of finite sums of elements, and thus pairs with functions on the group by evaluating the function on the summed elements.
|
Micrometer (device) Testing Micrometer_screw_gauge > Calibration: testing and adjusting > Testing A standard one-inch micrometer has readout divisions of 0.001 inch and a rated accuracy of ±0.0001 inch ("one tenth", in machinist parlance). Both the measuring instrument and the object being measured should be at room temperature for an accurate measurement; dirt, abuse, and low operator skill are the main sources of error.The accuracy of micrometers is checked by using them to measure gauge blocks, rods, or similar standards whose lengths are precisely and accurately known. If the gauge block is known to be 0.75000 ± 0.00005 inch ("seven-fifty plus or minus fifty millionths", that is, "seven hundred fifty thou plus or minus half a tenth"), then the micrometer should measure it as 0.7500 inch. If the micrometer measures 0.7503 inch, then it is out of calibration.
|
Computational sociology Macrosimulation and microsimulation Computational_sociology > History > Macrosimulation and microsimulation By the late 1960s and early 1970s, social scientists used increasingly available computing technology to perform macro-simulations of control and feedback processes in organizations, industries, cities, and global populations. These models used differential equations to predict population distributions as holistic functions of other systematic factors such as inventory control, urban traffic, migration, and disease transmission. Although simulations of social systems received substantial attention in the mid-1970s after the Club of Rome published reports predicting that policies promoting exponential economic growth would eventually bring global environmental catastrophe, the inconvenient conclusions led many authors to seek to discredit the models, attempting to make the researchers themselves appear unscientific. Hoping to avoid the same fate, many social scientists turned their attention toward micro-simulation models to make forecasts and study policy effects by modeling aggregate changes in state of individual-level entities rather than the changes in distribution at the population level. However, these micro-simulation models did not permit individuals to interact or adapt and were not intended for basic theoretical research.
|
Mitotic catastrophe Errors in mitosis Mitotic_catastrophe > Causes > Errors in mitosis Normally, cyclin B1 degradation is initiated by the anaphase promoting complex after all of the kinetochores have been properly attached by mitotic spindle fibers. However, when cyclin B1 levels are degraded too fast this can result in the cell exiting mitosis prematurely resulting in potential mitotic errors including missegregation of chromosomes.
|
Kinetic triangulation Summary Kinetic_triangulation A kinetic triangulation data structure is a kinetic data structure that maintains a triangulation of a set of moving points. Maintaining a kinetic triangulation is important for applications that involve motion planning, such as video games, virtual reality, dynamic simulations and robotics.
|
Privacy and blockchain IRS Privacy_and_blockchain > Legality of blockchain and privacy > IRS Because cryptocurrency prices fluctuate, many treat the purchase of cryptocurrencies as an investment. By purchasing these coins, buyers hope to later sell them at a higher price. Internal Revenue Service (IRS) are currentlyfacing struggles because many bitcoin holders do not include revenue from cryptocurrencies in their income reports, especially those who engage in many microtransactions. In response to these concerns, IRS issued a notice that people must apply general tax principles to cryptocurrency and treat the purchase of it as an investment or stock.
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.