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Y-fast trie Insert Y-fast_trie > Operations > Insert Inserting k into a balanced binary search tree that contains O(log M) elements also takes O(log log M) time. Splitting a binary search tree that contains O(log M) elements can be done in O(log log M) time. Finally, inserting and deleting the three representatives takes O(log M) time. However, since one splits the tree at most once every O(log M) insertions and deletions, this takes constant amortized time. Therefore, inserting a new key/value pair takes O(log log M) amortized time.
Arithmetic underflow Summary Arithmetic_underflow The term arithmetic underflow (also floating point underflow, or just underflow) is a condition in a computer program where the result of a calculation is a number of more precise absolute value than the computer can actually represent in memory on its central processing unit (CPU). Arithmetic underflow can occur when the true result of a floating point operation is smaller in magnitude (that is, closer to zero) than the smallest value representable as a normal floating point number in the target datatype. Underflow can in part be regarded as negative overflow of the exponent of the floating point value. For example, if the exponent part can represent values from −128 to 127, then a result with a value less than −128 may cause underflow.
Naturally aspirated engines Advantages Naturally_aspirated_engines > Advantages and disadvantages > Advantages Easier to maintain and repair Lower development and production costs Increased reliability, partly due to fewer separate, moving parts More direct throttle response than a turbo system due to the lack of turbo lag (an advantage also shared with superchargers) Less potential for overheating and or uncontrolled combustion (pinging/ knocking)
Forward–backward algorithm Backward probabilities Forward–backward_algorithm > Backward probabilities This is because the probabilities for each point are calculated independently of each other. They do not take into account the transition probabilities between states, and it is thus possible to get states at two moments (t and t+1) that are both most probable at those time points but which have very little probability of occurring together, i.e. P ( X t = x i , X t + 1 = x j ) ≠ P ( X t = x i ) P ( X t + 1 = x j ) {\displaystyle \mathbf {P} (X_{t}=x_{i},X_{t+1}=x_{j})\neq \mathbf {P} (X_{t}=x_{i})\mathbf {P} (X_{t+1}=x_{j})} . The most probable sequence of states that produced an observation sequence can be found using the Viterbi algorithm.
BCS theory Underlying evidence BCS_superconductor > Overview > Underlying evidence The hyperphysics website pages at Georgia State University summarize some key background to BCS theory as follows: Evidence of a band gap at the Fermi level (described as "a key piece in the puzzle")the existence of a critical temperature and critical magnetic field implied a band gap, and suggested a phase transition, but single electrons are forbidden from condensing to the same energy level by the Pauli exclusion principle. The site comments that "a drastic change in conductivity demanded a drastic change in electron behavior". Conceivably, pairs of electrons might perhaps act like bosons instead, which are bound by different condensate rules and do not have the same limitation.Isotope effect on the critical temperature, suggesting lattice interactionsThe Debye frequency of phonons in a lattice is proportional to the inverse of the square root of the mass of lattice ions.
Barn-pole paradox Shutting the ladder in the garage Barn-pole_paradox > Shutting the ladder in the garage In the above analysis, in its own frame, the ladder was always longer than the garage. So how did we ever close the doors and trap it inside? It is worth noting here a general feature of relativity: we have deduced, by considering the frame of the garage, that we do indeed trap the ladder inside the garage.
IBM Watson Health Intel IBM_Watson_Health > Industry considerations and challenges > Intel AI algorithms behave differently from humans in two ways: (1) algorithms are literal: if you set a goal, the algorithm can't adjust itself and only understand what it has been told explicitly, (2) and algorithms are black boxes; algorithms can predict extremely precise, but not the cause or the why.The primary aim of health-related AI applications is to analyze relationships between prevention or treatment techniques and patient outcomes. AI programs have been developed and applied to practices such as diagnosis processes, treatment protocol development, drug development, personalized medicine, and patient monitoring and care. Medical institutions such as The Mayo Clinic, Memorial Sloan Kettering Cancer Center, and National Health Service, have developed AI algorithms for their departments.
ARM TrustZone Instruction set ARM_architecture_family > 32-bit architecture > Instruction set Mostly single clock-cycle execution.To compensate for the simpler design, compared with processors like the Intel 80286 and Motorola 68020, some additional design features were used: Conditional execution of most instructions reduces branch overhead and compensates for the lack of a branch predictor in early chips. Arithmetic instructions alter condition codes only when desired.
Diffuse myelinoclastic sclerosis Symptoms and signs Diffuse_myelinoclastic_sclerosis > Symptoms and signs Symptoms are similar to those in multiple sclerosis and may include dementia, aphasia, seizures, personality changes, poor attention, tremors, balance instability, incontinence, muscle weakness, headache, vomiting, and vision and speech impairment. Other symptoms include weakness on one side of the body, muscle stiffness, hearing problems, and loss of bowel control.
Waterfall software development Supporting arguments Waterfall_Model > Supporting arguments Time spent early in the software production cycle can reduce costs at later stages. For example, a problem found in the early stages (such as requirements specification) is cheaper to fix than the same bug found later on in the process (by a factor of 50 to 200).In common practice, waterfall methodologies result in a project schedule with 20–40% of the time invested for the first two phases, 30–40% of the time to coding, and the rest dedicated to testing and implementation. The actual project organization needs to be highly structured. Most medium and large projects will include a detailed set of procedures and controls, which regulate every process on the project.A further argument for the waterfall model is that it places emphasis on documentation (such as requirements documents and design documents) as well as source code.
Wing-assisted incline running Origin of flight hypothesis Wing-assisted_incline_running > Origin of flight hypothesis The WAIR hypothesis for the origin of flight is a version of the "cursorial model" of the evolution of avian flight, in which birds' wings originated from forelimb modifications that provided downforce, enabling the proto-birds to run up extremely steep slopes such as the trunks of trees. The hypothesis was prompted by the observation of living young chukar chicks using WAIR, and proposes that dinosaur wings developed their aerodynamic functions as a result of the need to run quickly up very steep slopes such as tree trunks, possibly to escape from predators. Originally, it was thought that birds need downforce to give their feet increased grip in this scenario. However, a study found lift generated from wings to be the primary factor for successfully accelerating, indicating the onset of flight ability was constrained by neuromuscular control or power rather than by the shape of the wing itself, and that partially developed wings not yet capable of flight could indeed provide useful lift during WAIR.
Resonance energy Comparison with molecular orbital (MO) theory Resonance_energy > Quantum mechanical description in valence bond (VB) theory > Comparison with molecular orbital (MO) theory This MO interpretation has inspired the picture of the benzene ring as a hexagon with a circle inside. When describing benzene, the VB concept of localized σ bonds and the MO concept of delocalized π orbitals are frequently combined in elementary chemistry courses. The contributing structures in the VB model are particularly useful in predicting the effect of substituents on π systems such as benzene.
Vector dot product Complex vectors Dot_products > Generalizations > Complex vectors For vectors with complex entries, using the given definition of the dot product would lead to quite different properties. For instance, the dot product of a vector with itself could be zero without the vector being the zero vector (e.g. this would happen with the vector a = {\displaystyle \mathbf {a} =} ). This in turn would have consequences for notions like length and angle. Properties such as the positive-definite norm can be salvaged at the cost of giving up the symmetric and bilinear properties of the dot product, through the alternative definition where b i ¯ {\displaystyle {\overline {b_{i}}}} is the complex conjugate of b i {\displaystyle b_{i}} .
COVID-19 drug repurposing research Dexamethasone COVID-19_drug_repurposing_research > Steroids > Dexamethasone Dexamethasone is a corticosteroid medication in use for multiple conditions such as rheumatic problems, skin diseases, asthma and chronic obstructive lung disease among others. A multi-center, randomized controlled trial of dexamethasone in treating acute respiratory distress syndrome (ARDS), published in February 2020, showed reduced need for mechanical ventilation and mortality. Dexamethasone is only helpful in people requiring supplemental oxygen.
Comparison of open-source and closed-source software Code quality Comparison_of_open-source_and_closed-source_software > Innovation > Code quality In 2008, the Department of Management Science and Technology in the Athens University of Economics and Business published an analysis of the FreeBSD, Linux, Solaris, and Windows operating system kernels which looked for differences between code developed using open-source and proprietary processes. The study collected metrics in the areas of file organization, code structure, code style, the use of the C preprocessor, and data organization. The aggregate results indicated that they scored comparably to each other. Another study conducted by Synopsys published in 2014, found open source code to be of better quality.
Leader election Rings with unique IDs Leader_election > Algorithms > Leader election in rings > Rings with unique IDs In one of the early works, Chang and Roberts proposed a uniform algorithm in which a processor with the highest ID is selected as the leader. Each processor sends its ID in a clockwise direction. A process receiving a message and compares it with its own. If it is bigger, it passes it through, otherwise it will discard the message. They show that this algorithm uses at most O ( n 2 ) {\displaystyle O(n^{2})} messages and O ( n log ⁡ n ) {\displaystyle O(n\log n)} in the average case.Hirschberg and Sinclair improved this algorithm with O ( n log ⁡ n ) {\displaystyle O(n\log n)} message complexity by introducing a 2 directional message passing scheme allowing the processors to send messages in both directions.
Lens (vertebrate anatomy) Development Lens_nucleus > Structure > Development The lens continues to grow after birth, with the new secondary fibers being added as outer layers. New lens fibers are generated from the equatorial cells of the lens epithelium, in a region referred to as the "germinative zone" and "bow region". The lens epithelial cells elongate, lose contact with the capsule and epithelium at the back and front of the lens, synthesize crystallin, and then finally lose their nuclei (enucleate) as they become mature lens fibers.
Virtual DMA Services Summary Virtual_DMA_Services In computing, Virtual DMA Services (VDS) refer to an application programming interface that allow DOS and Win16 applications and device drivers to perform DMA operations while running under protected or virtual 8086 mode.
RDF triple Limitations RDF_triple > Limitations One concern about triple storage is its lack of database scalability. This problem is especially pertinent if millions of triples are stored and retrieved in a database. The seek time is larger than for classical SQL-based databases. A more complex issue is a knowledge model's inability to predict future states.
Aeromagnetic survey Method Aeromagnetic_survey > Method As the aircraft flies, the magnetometer measures and records the total intensity of the magnetic field at the sensor, which is a combination of the desired magnetic field generated in the Earth as well as tiny variations due to the temporal effects of the constantly varying solar wind and the magnetic field of the survey aircraft. By subtracting the solar, regional, and aircraft effects, the resulting aeromagnetic map shows the spatial distribution and relative abundance of magnetic minerals (most commonly the iron oxide mineral magnetite) in the upper levels of the Earth's crust. Because different rock types differ in their content of magnetic minerals, the magnetic map allows a visualization of the geological structure of the upper crust in the subsurface, particularly the spatial geometry of bodies of rock and the presence of faults and folds. This is particularly useful where bedrock is obscured by surface sand, soil or water.
Spring Constant Summary Force_constant It is also the fundamental principle behind the spring scale, the manometer, the galvanometer, and the balance wheel of the mechanical clock. The modern theory of elasticity generalizes Hooke's law to say that the strain (deformation) of an elastic object or material is proportional to the stress applied to it. However, since general stresses and strains may have multiple independent components, the "proportionality factor" may no longer be just a single real number, but rather a linear map (a tensor) that can be represented by a matrix of real numbers. In this general form, Hooke's law makes it possible to deduce the relation between strain and stress for complex objects in terms of intrinsic properties of the materials they are made of. For example, one can deduce that a homogeneous rod with uniform cross section will behave like a simple spring when stretched, with a stiffness k directly proportional to its cross-section area and inversely proportional to its length.
Cuckoo hashing Lookup Cuckoo_hashing > Operations > Lookup Cuckoo hashing uses two hash tables, T 1 {\displaystyle T_{1}} and T 2 {\displaystyle T_{2}} . Assuming r {\displaystyle r} is the length of each table, the hash functions for the two tables is defined as, h 1 , h 2: ∪ → { 0 , . . .
Transition metal catalyst Magnetism Transition_element > Characteristic properties > Magnetism Transition metal compounds are paramagnetic when they have one or more unpaired d electrons. In octahedral complexes with between four and seven d electrons both high spin and low spin states are possible. Tetrahedral transition metal complexes such as 2− are high spin because the crystal field splitting is small so that the energy to be gained by virtue of the electrons being in lower energy orbitals is always less than the energy needed to pair up the spins. Some compounds are diamagnetic.
Closed-loop recycling Summary Closed-loop_recycling Closed-loop recycling is the process by which a product or material can be used and then turned into a new product (or converted back to raw material) indefinitely without losing its properties during the recycling process.By reducing the production and use of raw materials, closed-loop recycling minimizes harm to the environment and discourages resource depletion. In contrast, open-loop recycling is the process by which a product is recycled but has to be mixed with raw materials to become a new product, typically leading to downcycling.Ideal closed-loop systems produce no waste. They are called "closed" because products have a circular life cycle, beginning as raw materials and either being recycled into replacement products, returning to the original raw materials, or being returned to the environment as biodegradable waste. This reduces the amount of (non-biodegradable) waste disposed, as recyclables are recovered and reused, rather than ending up in a landfill or as a pollutant.
Critical line theorem Growth of arithmetic functions Critical_line_theorem > Consequences > Growth of arithmetic functions A typical example is Robin's theorem, which states that if σ(n) is the sigma function, given by σ ( n ) = ∑ d ∣ n d {\displaystyle \sigma (n)=\sum _{d\mid n}d} then σ ( n ) < e γ n log ⁡ log ⁡ n {\displaystyle \sigma (n) 5040 if and only if the Riemann hypothesis is true, where γ is the Euler–Mascheroni constant. A related bound was given by Jeffrey Lagarias in 2002, who proved that the Riemann hypothesis is equivalent to the statement that: σ ( n ) < H n + log ⁡ ( H n ) e H n {\displaystyle \sigma (n) 1, where H n {\displaystyle H_{n}} is the nth harmonic number.The Riemann hypothesis is also true if and only if the inequality n φ ( n ) < e γ log ⁡ log ⁡ n + e γ ( 4 + γ − log ⁡ 4 π ) log ⁡ n {\displaystyle {\frac {n}{\varphi (n)}} 0 ∑ i = 1 m \| F n ( i ) − i m \| = O ( n 1 2 + ϵ ) {\displaystyle \sum _{i=1}^{m}\|F_{n}(i)-{\tfrac {i}{m}}\|=O\left(n^{{\frac {1}{2}}+\epsilon }\right)} is equivalent to the Riemann hypothesis. Here m = ∑ i = 1 n ϕ ( i ) {\displaystyle m=\sum _{i=1}^{n}\phi (i)} is the number of terms in the Farey sequence of order n. For an example from group theory, if g(n) is Landau's function given by the maximal order of elements of the symmetric group Sn of degree n, then Massias, Nicolas & Robin (1988) showed that the Riemann hypothesis is equivalent to the bound log ⁡ g ( n ) < Li − 1 ⁡ ( n ) {\displaystyle \log g(n)<{\sqrt {\operatorname {Li} ^{-1}(n)}}} for all sufficiently large n.
Automatic Voltage Regulator Comparing linear versus switching regulators Constant-voltage_transformer > Active regulators > Comparing linear versus switching regulators Switched Mode Power Supplies are basically DC–DC converters. If the input is AC, the input is first rectified to DC voltage. So depending on the input, an SMPS may have two (DC–AC, AC–DC) or three (AC–DC, DC–AC, AC–DC) stages. The two types of regulators have their different advantages: Linear regulators are best when low output noise (and low RFI radiated noise) is required Linear regulators are best when a fast response to input and output disturbances is required At low power levels, linear regulators are cheaper and occupy less printed circuit board space Switching regulators are best when power efficiency is critical (such as in portable computers), except that linear regulators are more efficient in a small number of cases (such as a 5 V microprocessor often in "sleep" mode fed from a 6 V battery, if the complexity of the switching circuit and the junction capacitance charging current means a high quiescent current in the switching regulator) Switching regulators are required when the only power supply is a DC voltage, and a higher output voltage is required. At power levels above a few watts, switching regulators are cheaper (for example, the cost of removing heat generated is less)
Envelope stress response Summary Envelope_stress_response Bacteria can react simultaneously to a variety of stresses and the various stress response systems interact (cross-talk) with each other. A complex network of global regulatory systems leads to a coordinated and effective response. These regulatory systems govern the expression of more effectors that maintain stability of the cellular equilibrium under the various conditions.
Physiological development Fertilization Development_of_the_human_body > Before birth > Fertilization Fertilization occurs when the sperm successfully enters the ovum's membrane. The chromosomes of the sperm are passed into the egg to form a unique genome. The egg becomes a zygote and the germinal stage of embryonic development begins. The germinal stage refers to the time from fertilization, through the development of the early embryo, up until implantation.
Electrical networks Summary Electrical_Circuit An electrical network is an interconnection of electrical components (e.g., batteries, resistors, inductors, capacitors, switches, transistors) or a model of such an interconnection, consisting of electrical elements (e.g., voltage sources, current sources, resistances, inductances, capacitances). An electrical circuit is a network consisting of a closed loop, giving a return path for the current. Thus all circuits are networks, but not all networks are circuits (although networks without a closed loop are often imprecisely referred to as "circuits").
Complex system biology Associated disciplines Complex_systems_biology > Associated disciplines An example of the bottom up approach is the use of circuit models to describe a simple gene network.Various technologies utilized to capture dynamic changes in mRNA, proteins, and post-translational modifications. Mechanobiology, forces and physical properties at all scales, their interplay with other regulatory mechanisms; biosemiotics, analysis of the system of sign relations of an organism or other biosystems; Physiomics, a systematic study of physiome in biology. Cancer systems biology is an example of the systems biology approach, which can be distinguished by the specific object of study (tumorigenesis and treatment of cancer).
Boltzmann machine Training Boltzmann_machine > Training The other is the "negative" phase where the network is allowed to run freely, i.e. only the input nodes have their state determined by external data, but the output nodes are allowed to float. The gradient with respect to a given weight, w i j {\displaystyle w_{ij}} , is given by the equation: ∂ G ∂ w i j = − 1 R {\displaystyle {\frac {\partial {G}}{\partial {w_{ij}}}}=-{\frac {1}{R}}} where: p i j + {\displaystyle p_{ij}^{+}} is the probability that units i and j are both on when the machine is at equilibrium on the positive phase. p i j − {\displaystyle p_{ij}^{-}} is the probability that units i and j are both on when the machine is at equilibrium on the negative phase.
Quantum revolution Summary Quantum_revolution The Bohr–Einstein debates were a series of public disputes about quantum mechanics between Albert Einstein and Niels Bohr. Their debates are remembered because of their importance to the philosophy of science, insofar as the disagreements—and the outcome of Bohr's version of quantum mechanics becoming the prevalent view—form the root of the modern understanding of physics. Most of Bohr's version of the events held in Solvay in 1927 and other places was first written by Bohr decades later in an article titled, "Discussions with Einstein on Epistemological Problems in Atomic Physics". Based on the article, the philosophical issue of the debate was whether Bohr's Copenhagen Interpretation of quantum mechanics, which centered on his belief of complementarity, was valid in explaining nature. Despite their differences of opinion and the succeeding discoveries that helped solidify quantum mechanics, Bohr and Einstein maintained a mutual admiration that was to last the rest of their lives.Although Bohr and Einstein disagreed, they were great friends all their lives and enjoyed using each other as a foil.
Debye–Hückel equation Summary of Debye and Hückel's first article on the theory of dilute electrolytes Debye–Hückel_equation > Summary of Debye and Hückel's first article on the theory of dilute electrolytes In the same year they first published this article, Debye and Hückel, hereinafter D&H, also released an article that covered their initial characterization of solutions under the influence of electric fields called "On the Theory of Electrolytes. II. Limiting Law for Electric Conductivity", but that subsequent article is not (yet) covered here. In the following summary (as yet incomplete and unchecked), modern notation and terminology are used, from both chemistry and mathematics, in order to prevent confusion. Also, with a few exceptions to improve clarity, the subsections in this summary are (very) condensed versions of the same subsections of the original article.
Distributed programming Complexity measures Distributed_programming > Theoretical foundations > Complexity measures On the other hand, if the running time of the algorithm is much smaller than D communication rounds, then the nodes in the network must produce their output without having the possibility to obtain information about distant parts of the network. In other words, the nodes must make globally consistent decisions based on information that is available in their local D-neighbourhood. Many distributed algorithms are known with the running time much smaller than D rounds, and understanding which problems can be solved by such algorithms is one of the central research questions of the field.
Fractional Fourier transform Generalizations Fractional_Fourier_transform > Definition > Generalizations The Fourier transform is essentially bosonic; it works because it is consistent with the superposition principle and related interference patterns. There is also a fermionic Fourier transform. These have been generalized into a supersymmetric FRFT, and a supersymmetric Radon transform.
Ureidopenicillin Summary Ureidopenicillin The ureidopenicillins are a group of penicillins which are active against Pseudomonas aeruginosa.There are three ureidopenicillins in clinical use: Azlocillin Piperacillin MezlocillinThey are mostly ampicillin derivatives in which the amino acid side chain has been converted to a variety of cyclic ureas. It is speculated that the added side chain mimics a longer segment of the peptidoglycan chain, more than ampicillin, and thus would bind more easily to the penicillin-binding proteins. Ureidopenicillins are not resistant to beta-lactamases.They are used parenterally, and are particularly indicated in infections caused by Gram-negative bacteria. == References ==
Zetetic Elench Energy manipulation Zetetic_Elench > Science and technology > Energy manipulation A major feature of its post-scarcity society, the Culture is obviously able to gather, manipulate, transfer and store vast amounts of energy. While not explained in detail in the novels, this involves antimatter and the "energy grid", a postulated energy field dividing the universe from neighboring anti-matter universes, and providing practically limitless energy. Transmission or storage of such energy is not explained, though these capabilities must be powerful as well, with tiny drones capable of very powerful manipulatory fields and forces.
RNA-binding protein database Background Information about RNA Binding Protein RNA-binding_protein_database > Background Information about RNA Binding Protein Transcription and translation processes are different in prokaryotes and eukaryotes. Unlike prokaryotes, these two processes occur separately in eukaryote's nucleus and cytoplasm. Because of this, eukaryotes apply a strategy called post-transcriptional modification which includes splicing, editing and polyadenylation to process the pre-mRNA. RNA-binding proteins ( RBPs ) play critical role during this process.
N2 Chart Examples N2_diagram > Examples Figure 6 is an example of the diagram's appearance when cells are populated with data.
History of loop quantum gravity Classical theories of gravitation History_of_loop_quantum_gravity > History > Classical theories of gravitation General relativity is the theory of gravitation published by Albert Einstein in 1915. According to it, the force of gravity is a manifestation of the local geometry of spacetime. Mathematically, the theory is modelled after Bernhard Riemann's metric geometry, but the Lorentz group of spacetime symmetries (an essential ingredient of Einstein's own theory of special relativity) replaces the group of rotational symmetries of space. (Later, loop quantum gravity inherited this geometric interpretation of gravity, and posits that a quantum theory of gravity is fundamentally a quantum theory of spacetime.)
Bernoulli operator Summary Bernoulli_operator In mathematics, the transfer operator encodes information about an iterated map and is frequently used to study the behavior of dynamical systems, statistical mechanics, quantum chaos and fractals. In all usual cases, the largest eigenvalue is 1, and the corresponding eigenvector is the invariant measure of the system. The transfer operator is sometimes called the Ruelle operator, after David Ruelle, or the Perron–Frobenius operator or Ruelle–Perron–Frobenius operator, in reference to the applicability of the Perron–Frobenius theorem to the determination of the eigenvalues of the operator.
Lysosomal enzymes Discovery Lysosomal_enzymes > Discovery Christian de Duve, at the Laboratory of Physiological Chemistry at the Catholic University of Louvain in Belgium, had been studying the mechanism of action of insulin in liver cells. By 1949, he and his team had focused on the enzyme called glucose 6-phosphatase, which is the first crucial enzyme in sugar metabolism and the target of insulin. They already suspected that this enzyme played a key role in regulating blood sugar levels. However, even after a series of experiments, they failed to purify and isolate the enzyme from the cellular extracts.
Colonoscopy Colon cancer screening Colonoscopy > Medical uses > Colon cancer screening Of the 28,220 people in the invited group, 11,843 (42.0%) underwent screening. A total of 15 people who underwent colonoscopy (0.13%) had major bleeding after polyp removal. None of the participants experienced a colon perforation due to colonoscopy.
C2H5Cl Safety Ethyl_chloride > Safety At >12% concentration, the victim's heart, lungs and kidneys begin to fail. Immediate CPR followed by medical support measures may be required to prevent fatal kidney, lung and heart failure.
Theoretical planetology Nature of the work Theoretical_planetology > Nature of the work Theoretical planetologists, also known as theoretical planetary scientists, use modelling techniques to develop an understanding of the internal structure of planets by making assumptions about their chemical composition and the state of their materials, then calculating the radial distribution of various properties such as temperature, pressure, or density of material across the planet's internals.Theoretical planetologists also use numerical models to understand how the Solar System planets were formed and develop in the future, their thermal evolution, their tectonics, how magnetic fields are formed in planetary interiors, how convection processes work in the cores and mantles of terrestrial planets and in the interiors of gas giants, how their lithospheres deform, the orbital dynamics of planetary satellites, how dust and ice are transported on the surface of some planets (such as Mars), and how the atmospheric circulation takes place over a planet.Theoretical planetologists may use laboratory experiments to understand various phenomena analogous to planetary processes, such as convection in rotating fluids.Theoretical planetologists make extensive use of basic physics, particularly fluid dynamics and condensed matter physics, and much of their work involves interpretation of data returned by space missions, although they rarely get actively involved in them.
User-Mode Driver Framework Version history User-Mode_Driver_Framework > Version history User-Mode Driver Framework 1.5-1.9, supports Windows XP and newer. User-Mode Driver Framework 1.11, supports Windows Vista and later, and Windows Server 2008 and later. User-Mode Driver Framework 2.0, which supports Windows 8.1 and newer.
Right module Summary Module_(ring_theory) In mathematics, a module is a generalization of the notion of vector space in which the field of scalars is replaced by a ring. The concept of module generalizes also the notion of abelian group, since the abelian groups are exactly the modules over the ring of integers. Like a vector space, a module is an additive abelian group, and scalar multiplication is distributive over the operation of addition between elements of the ring or module and is compatible with the ring multiplication. Modules are very closely related to the representation theory of groups. They are also one of the central notions of commutative algebra and homological algebra, and are used widely in algebraic geometry and algebraic topology.
Mathematical constant Constants in advanced mathematics Mathematical_constants > Constants in advanced mathematics These are constants which are encountered frequently in higher mathematics.
Viscosity models for mixtures Elementary kinetic theory Viscosity_models_for_mixtures > Dilute gas limit and scaled variables > Elementary kinetic theory The positive part models the repulsive forces as the electron clouds of the two molecules overlap. The radius for zero interaction potential is therefore appropriate for estimating (or defining) the collision cross section in kinetic gas theory, and the r-parameter (conf. r , r i {\displaystyle r,r_{i}} ) is therefore called kinetic radius.
Forced vibration Damped and undamped natural frequencies Vibration_analysis > Analysis > Free vibration with damping > Damped and undamped natural frequencies {\displaystyle f_{\text{d}}=f_{n}{\sqrt {1-\zeta ^{2}}}.} The damped natural frequency is less than the undamped natural frequency, but for many practical cases the damping ratio is relatively small and hence the difference is negligible.
Renormalization group flow Exact renormalization group equations Renormalization_group_flow > Exact renormalization group equations As there are infinitely many choices of Rk, there are also infinitely many different interpolating ERGEs. Generalization to other fields like spinorial fields is straightforward. Although the Polchinski ERGE and the effective average action ERGE look similar, they are based upon very different philosophies.
G2 phase Positive feedback and switch-like activation G2_phase > End of G2/entry into mitosis > Positive feedback and switch-like activation Secondly, it is also vital that the G2/M transition occur unidirectionally, or only once per cell cycle Biological systems are inherently noisy, and small fluctuations in cyclin B1 concentrations near the threshold for the G2/M transition should not cause the cell to switch back and forth between interphase and M-phase states. This is ensured by the bistable nature of the switch: after the cell transitions to the M-phase state, small decreases in the concentration of cyclin B do not cause the cell to switch back to interphase. Finally, the continuation of the cell cycle requires persisting oscillations in cyclin-B/CDK1 activity as the cell and its descendants transition in and out of M-phase.
Sedimentary Rock Depositional environments Sedimentary_Rock > Depositional environments Warm shallow marine environments also are ideal environments for coral reefs, where the sediment consists mainly of the calcareous skeletons of larger organisms.In deep marine environments, the water current working the sea bottom is small. Only fine particles can be transported to such places.
True RMS voltmeter Peak-to-peak amplitude Peak-to-peak_amplitude > Definitions > Peak-to-peak amplitude Peak-to-peak amplitude (abbreviated p–p) is the change between peak (highest amplitude value) and trough (lowest amplitude value, which can be negative). With appropriate circuitry, peak-to-peak amplitudes of electric oscillations can be measured by meters or by viewing the waveform on an oscilloscope. Peak-to-peak is a straightforward measurement on an oscilloscope, the peaks of the waveform being easily identified and measured against the graticule. This remains a common way of specifying amplitude, but sometimes other measures of amplitude are more appropriate.
Light dependent reaction In bacteria Light_dependent_reaction > In bacteria PSII, PSI, and cytochrome b6f are found in chloroplasts. All plants and all photosynthetic algae contain chloroplasts, which produce NADPH and ATP by the mechanisms described above. In essence, the same transmembrane structures are also found in cyanobacteria. Unlike plants and algae, cyanobacteria are prokaryotes.
Matrix scheme Operation Matrix_scheme > Operation It is this orderly movement which has also given the name "elevator scheme" to these sites, as people move up the "elevator" (escalator, ladder) to the top at which they would then "cycle" out of the matrix. In such a matrix, 9 out of 10, or 90 percent, of all customers will not receive the reward item, because the rules of the scheme are that one reward is issued for every 10 customers that join. (The fact that the reward is issued to the customer at the top of the list doesn't change the proportion of rewards given to customers signed up.)
Transparent plastic Compounding Polymer_additive > Plastic industry > Compounding Companies that specialize in this work are known as Compounders. The compounding of thermosetting plastic is relatively straightforward; as it remains liquid until it is cured into its final form. For thermosoftening materials, which are used to make the majority of products, it is necessary to melt the plastic in order to mix-in the additives.
Multitask optimization Summary Multitask_optimization Multi-task optimization is a paradigm in the optimization literature that focuses on solving multiple self-contained tasks simultaneously. The paradigm has been inspired by the well-established concepts of transfer learning and multi-task learning in predictive analytics. The key motivation behind multi-task optimization is that if optimization tasks are related to each other in terms of their optimal solutions or the general characteristics of their function landscapes, the search progress can be transferred to substantially accelerate the search on the other. The success of the paradigm is not necessarily limited to one-way knowledge transfers from simpler to more complex tasks. In practice an attempt is to intentionally solve a more difficult task that may unintentionally solve several smaller problems.
Data hierarchy Summary Data_hierarchy Data hierarchy refers to the systematic organization of data, often in a hierarchical form. Data organization involves characters, fields, records, files and so on. This concept is a starting point when trying to see what makes up data and whether data has a structure. For example, how does a person make sense of data such as 'employee', 'name', 'department', 'Marcy Smith', 'Sales Department' and so on, assuming that they are all related?
Microsoft Sync Framework Architecture Microsoft_Sync_Framework > Architecture In addition, they also have to maintain synchronization metadata and the state of the data store, so that changes can be enumerated quickly. The metadata is maintained for every instance of the data store (replica) that the provider is attached to. The metadata maintained includes the replica ID, tick count (representing progression in time), conflict log, tombstone log, and the set of the changes the data store has seen (knowledge).
History of programming languages First programming languages History_of_programming_languages > First programming languages It is still a popular language for high-performance computing and is used for programs that benchmark and rank the world's TOP500 fastest supercomputers.Another early programming language was devised by Grace Hopper in the US, named FLOW-MATIC. It was developed for the UNIVAC I at Remington Rand during the period from 1955 until 1959. Hopper found that business data processing customers were uncomfortable with mathematical notation, and in early 1955, she and her team wrote a specification for an English language programming language and implemented a prototype.
Causal loop diagram Reinforcing and balancing loops Causal_loop_diagram > Reinforcing and balancing loops To determine if a causal loop is reinforcing or balancing, one can start with an assumption, e.g. "Variable 1 increases" and follow the loop around. The loop is: reinforcing if, after going around the loop, one ends up with the same result as the initial assumption. balancing if the result contradicts the initial assumption.Or to put it in other words: reinforcing loops have an even number of negative links (zero also is even, see example below) balancing loops have an odd number of negative links.Identifying reinforcing and balancing loops is an important step for identifying Reference Behaviour Patterns, i.e. possible dynamic behaviours of the system. Reinforcing loops are associated with exponential increases/decreases. Balancing loops are associated with reaching a plateau.If the system has delays (often denoted by drawing a short line across the causal link), the system might fluctuate.
Extraneous variables In modeling and statistics Response_variable > In modeling and statistics In mathematical modeling, the dependent variable is studied to see if and how much it varies as the independent variables vary. In the simple stochastic linear model yi = a + bxi + ei the term yi is the ith value of the dependent variable and xi is the ith value of the independent variable. The term ei is known as the "error" and contains the variability of the dependent variable not explained by the independent variable. With multiple independent variables, the model is yi = a + bxi,1 + bxi,2 + ... + bxi,n + ei, where n is the number of independent variables.In statistics, more specifically in linear regression, a scatter plot of data is generated with X as the independent variable and Y as the dependent variable.
Cholestatic hepatitis Mechanisms of drug-induced cholestasis Cholestatic_hepatitis > Mechanism > Mechanisms of drug-induced cholestasis Indeed, the cholestatic effect of cyclosporine A relies on its inhibition of both NTCP and the compensatory OATP1B1.In addition to direct inhibition, drugs can also induce cholestasis by promoting downregulation and internalization of transporters. For example, cyclosporine A in rats was shown to induce BSEP internalization in addition to inhibition. Furthermore, human hepatocytes showed decreased expression of BSEP mRNA and protein following long-term exposure to metformin and tamoxifen, neither of which are direct BSEP inhibitors.Bile canaliculi dynamics refers to the contractile motion of bile canaliculi (ducts) required for bile flow.
Matched filter Biology Matched_filter > Examples > Biology Animals living in relatively static environments would have relatively fixed features of the environment to perceive. This allows the evolution of filters that match the expected signal with the highest signal-to-noise ratio, the matched filter. Sensors that perceive the world "through such a 'matched filter' severely limits the amount of information the brain can pick up from the outside world, but it frees the brain from the need to perform more intricate computations to extract the information finally needed for fulfilling a particular task."
Radical probabilism Background Radical_probabilism > Background Bayes' theorem states a rule for updating a probability conditioned on other information. In 1967, Ian Hacking argued that in a static form, Bayes' theorem only connects probabilities that are held simultaneously; it does not tell the learner how to update probabilities when new evidence becomes available over time, contrary to what contemporary Bayesians suggested.According to Hacking, adopting Bayes' theorem is a temptation. Suppose that a learner forms probabilities Pold(A & B) = p and Pold(B) = q. If the learner subsequently learns that B is true, nothing in the axioms of probability or the results derived therefrom tells him how to behave. He might be tempted to adopt Bayes' theorem by analogy and set his Pnew(A) = Pold(A \| B) = p/q.
Data Modeling Overview Data_modelling > Overview The conceptual model is then translated into a logical data model, which documents structures of the data that can be implemented in databases. Implementation of one conceptual data model may require multiple logical data models. The last step in data modeling is transforming the logical data model to a physical data model that organizes the data into tables, and accounts for access, performance and storage details.
Scientific methodology Communication and community Scientific_methodology > Communication and community Frequently the scientific method is employed not only by a single person but also by several people cooperating directly or indirectly. Such cooperation can be regarded as an important element of a scientific community. Various standards of scientific methodology are used within such an environment.
Crack closure Plasticity-induced crack closure Crack_closure > Crack closure mechanisms > Plasticity-induced crack closure The phenomenon of plasticity-induced crack closure is associated with the development of residual plastically deformed material on the flanks of an advancing fatigue crack.The degree of plasticity at the crack tip is influenced by the level of material constraint. The two extreme cases are: Under plane stress conditions, the piece of material in the plastic zone is elongated, which is mainly balanced by an out-of-the-plane flow of the material. Hence, the plasticity-induced crack closure under plane stress conditions can be expressed as a consequence of the stretched material behind the crack tip, which can be considered as a wedge that is inserted in the crack and reduces the cyclic plastic deformation at the crack tip and hence the fatigue crack growth rate.
Just in Sequence Introduction of JIS concepts Just_in_Sequence > Just in sequence is just in time > Introduction of JIS concepts Just In Sequence processes are typically implemented only after the company has achieved a high degree of competency on Just In Time processes. The first step for the organization is to implement JIT processes to synchronize all manufacturing and material departments inside the plant and to collaborate with suppliers, customers, and sub-contractors to reduce inventory buffers to within a few hours. This process typically uncovers deep manufacturing and logistic issues that are not easy to overcome (see JIT Implementation for more details). The manufacturing company can only benefit from sequencing items once these problems have been resolved successfully and components are delivered Just In Time. Sequencing can be implemented in a Just In Time supply operation at many levels, bringing ever-higher inventory reduction and financial benefits:
Monad (functional programming) History Monads_in_functional_programming > History When formalized in category-theoretic terms, this leads to the conclusion that monads are the structure to represent these computations.Several others popularized and built on this idea, including Philip Wadler and Simon Peyton Jones, both of whom were involved in the specification of Haskell. In particular, Haskell used a problematic "lazy stream" model up through v1.2 to reconcile I/O with lazy evaluation, until switching over to a more flexible monadic interface. The Haskell community would go on to apply monads to many problems in functional programming, and in the 2010s, researchers working with Haskell eventually recognized that monads are applicative functors; and that both monads and arrows are monoids.At first, programming with monads was largely confined to Haskell and its derivatives, but as functional programming has influenced other paradigms, many languages have incorporated a monad pattern (in spirit if not in name). Formulations now exist in Scheme, Perl, Python, Racket, Clojure, Scala, F#, and have also been considered for a new ML standard.
Ocean salinity Relationship of currents and climate Ocean_layer > Physical properties > Ocean currents and global climate > Relationship of currents and climate It plays an important role in supplying heat to the polar regions, and thus in sea ice regulation. Oceans moderate the climate of locations where prevailing winds blow in from the ocean. At similar latitudes, a place on Earth with more influence from the ocean will have a more moderate climate than a place with more influence from land.
Complex Instruction Set Computing New instructions CISC_instruction > Incitements and benefits > New instructions In the 1970s, analysis of high-level languages indicated compilers produced some complex corresponding machine language. It was determined that new instructions could improve performance. Some instructions were added that were never intended to be used in assembly language but fit well with compiled high-level languages.
Glossary of electrical and electronics engineering E Glossary_of_electrical_and_electronics_engineering > E electrical conductivity A measure of a substance's ability to pass an electric current. electrical conductor An object that carries an electric current, with little loss. electrical contact A separable part of an electric device that carries current when touching another contact.
Plan-position indicator Description Plan-position_indicator > Description This change is not a straight line but a curve as the surface of the Earth is curved and sinks below the radar horizon. For fixed-site installations, north is usually represented at the top of the image.
Choice Number of options and paradox Choice > Number of options and paradox On the other hand, people who refrain from taking better choices through drugs or other forms of escapism tend to be much happier in life. Others say that there is never too much choice and that there is a difference between happiness and satisfaction: a person who tries to find better decisions will often be dissatisfied, but not necessarily unhappy since his attempts at finding better choices did improve his lifestyle (even if it wasn't the best decision he will continually try to incrementally improve the decisions he takes). Choice architecture is the process of encouraging people to make good choices through grouping and ordering the decisions in a way that maximizes successful choices and minimizes the number of people who become so overwhelmed by complexity that they abandon the attempt to choose. Generally, success is improved by presenting the smaller or simpler choices first, and by choosing and promoting sensible default options.
Higgs Field Nickname Higgs_Field > Public discussion > Naming > Nickname The book sought in part to promote awareness of the significance and need for such a project in the face of its possible loss of funding. Lederman, a leading researcher in the field, writes that he wanted to title his book The Goddamn Particle: If the Universe is the Answer, What is the Question? Lederman's editor decided that the title was too controversial and convinced him to change the title to The God Particle: If the Universe is the Answer, What is the Question?While media use of this term may have contributed to wider awareness and interest, many scientists feel the name is inappropriate since it is sensational hyperbole and misleads readers; the particle also has nothing to do with any God, leaves open numerous questions in fundamental physics, and does not explain the ultimate origin of the universe.
Algal blooms Marine algal blooms Algal_toxin > Marine algal blooms The visualization on the left immediately below uses NASA SeaWiFS data to map bloom populations.The NAAMES study conducted between 2015 and 2019 investigated aspects of phytoplankton dynamics in ocean ecosystems, and how such dynamics influence atmospheric aerosols, clouds, and climate. In France, citizens are requested to report coloured waters through the project PHENOMER. This helps to understand the occurrence of marine blooms.Wildfires can cause phytoplankton blooms via oceanic deposition of wildfire aerosols.
Doppler cooling limit Detailed explanation Doppler_Limit > Detailed explanation Atoms in that band are the only ones that interact with the left laser. When a photon from the left laser slams into one of those atoms, it suddenly slows down an amount corresponding to the momentum of that photon (the dot would be redrawn some fixed "quantum" distance further to the right). If the atom releases the photon directly to the right, then the dot is redrawn that same distance to the left, putting it back in the narrow band of interaction.
Transposable elements Mechanisms of mutagenesis Mobile_element > Negative effects > Mechanisms of mutagenesis TEs are mutagens and due to the contribution to the formation of new cis-regulatory DNA elements that are connected to many transcription factors that are found in living cells; TEs can undergo many evolutionary mutations and alterations. These are often the causes of genetic disease, and gives the potential lethal effects of ectopic expression.TEs can damage the genome of their host cell in different ways: A transposon or a retrotransposon that inserts itself into a functional gene can disable that gene. After a DNA transposon leaves a gene, the resulting gap may not be repaired correctly. Multiple copies of the same sequence, such as Alu sequences, can hinder precise chromosomal pairing during mitosis and meiosis, resulting in unequal crossovers, one of the main reasons for chromosome duplication.TEs use a number of different mechanisms to cause genetic instability and disease in their host genomes.
URL address Summary URL_address A Uniform Resource Locator (URL), colloquially known as an address on the Web, is a reference to a resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifier (URI), although many people use the two terms interchangeably. URLs occur most commonly to reference web pages (HTTP/HTTPS) but are also used for file transfer (FTP), email (mailto), database access (JDBC), and many other applications. Most web browsers display the URL of a web page above the page in an address bar. A typical URL could have the form http://www.example.com/index.html, which indicates a protocol (http), a hostname (www.example.com), and a file name (index.html).
Knot Theory Conway notation Knot_equivalence > Tabulating knots > Conway notation The 2 −3 2 is a sequence describing the continued fraction associated to a rational tangle. One inserts this tangle at the vertex of the basic polyhedron 1. A more complicated example is 83.1.2 0.1.1.1.1.1 Here again 8* refers to a basic polyhedron with 8 vertices.
Critical line (mathematics) Ihara zeta functions Critical_line_theorem > Generalizations and analogs > Ihara zeta functions The Ihara zeta function of a finite graph is an analogue of the Selberg zeta function, which was first introduced by Yasutaka Ihara in the context of discrete subgroups of the two-by-two p-adic special linear group. A regular finite graph is a Ramanujan graph, a mathematical model of efficient communication networks, if and only if its Ihara zeta function satisfies the analogue of the Riemann hypothesis as was pointed out by T. Sunada.
Minimum mean square error Example 2 Minimum_mean_square_error > Examples > Example 2 Consider a vector y {\displaystyle y} formed by taking N {\displaystyle N} observations of a fixed but unknown scalar parameter x {\displaystyle x} disturbed by white Gaussian noise. We can describe the process by a linear equation y = 1 x + z {\displaystyle y=1x+z} , where 1 = T {\displaystyle 1=^{T}} . Depending on context it will be clear if 1 {\displaystyle 1} represents a scalar or a vector. Suppose that we know {\displaystyle } to be the range within which the value of x {\displaystyle x} is going to fall in.
Kairbaan Hodivala-Dilke Research interests Kairbaan_Hodivala-Dilke > Research interests Recent investigations have increased understanding of the role that stromal focal adhesion kinase (FAK) plays in tumour growth, progression and resistance to chemotherapy. Hodivala-Dilke's research goal is to study how the tumour microenvironment can control tumour progression and cancer treatment efficacy.Hodivala-Dilke’s team at Barts Cancer Institute have established the role of stromal focal adhesion kinase (FAK) in chemoresistance. The team have pioneered a novel concept in vascular promotion using low doses of RGD mimetics in enhancing the efficacy of cancer therapy. The team’s overall goal is to discover novel therapeutic vascular targets to modulate stromal control in the control of cancer.
F orbital Summary Electron_clouds In atomic theory and quantum mechanics, an atomic orbital () is a function describing the location and wave-like behavior of an electron in an atom. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus. The term atomic orbital may also refer to the physical region or space where the electron can be calculated to be present, as predicted by the particular mathematical form of the orbital.Each orbital in an atom is characterized by a set of values of the three quantum numbers n, ℓ, and ml, which respectively correspond to the electron's energy, its angular momentum, and an angular momentum vector component (magnetic quantum number). As an alternative to the magnetic quantum number, the orbitals are often labeled by the associated harmonic polynomials (e.g., xy, x2 − y2).
William Lipscomb Boron chemistry and the nature of the chemical bond William_Lipscomb > Scientific studies > Boron chemistry and the nature of the chemical bond Later he applied the same methods to related problems, including the structure of carboranes (compounds of carbon, boron, and hydrogen). Longuet-Higgins and Roberts discussed the electronic structure of an icosahedron of boron atoms and of the borides MB6. The mechanism of the three-center two-electron bond was also discussed in a later paper by Longuet-Higgins, and an essentially equivalent mechanism was proposed by Eberhardt, Crawford, and Lipscomb.
Anti-greenhouse effect Summary Anti-greenhouse_effect The anti-greenhouse effect is a process that occurs when energy from a celestial object's sun is absorbed or scattered by the object's upper atmosphere, preventing that energy from reaching the surface, which results in surface cooling – the opposite of the greenhouse effect. In an ideal case where the upper atmosphere absorbs all sunlight and is nearly transparent to infrared (heat) energy from the surface, the surface temperature would be reduced by 16%, which is a significant amount of cooling. This case is described in more detail below. Coined by Dr. Christopher McKay in 1991, the anti-greenhouse effect was first observed on Saturn's moon, Titan.
Algorithmic problem Ancient algorithms Algorithmic_method > History > Ancient algorithms Since antiquity, step-by-step procedures for solving mathematical problems have been attested. This includes Babylonian mathematics (around 2500 BC), Egyptian mathematics (around 1550 BC), Indian mathematics (around 800 BC and later; e.g. Shulba Sutras, Kerala School, and Brāhmasphuṭasiddhānta), The Ifa Oracle (around 500 BC), Greek mathematics (around 240 BC, e.g. sieve of Eratosthenes and Euclidean algorithm), and Arabic mathematics (9th century, e.g. cryptographic algorithms for code-breaking based on frequency analysis).
C Sharp language Memory access C_Sharp_language > Distinguishing features > Memory access Code that is not marked as unsafe can still store and manipulate pointers through the System.IntPtr type, but it cannot dereference them. Managed memory cannot be explicitly freed; instead, it is automatically garbage collected. Garbage collection addresses the problem of memory leaks by freeing the programmer of responsibility for releasing memory that is no longer needed in most cases. Code that retains references to objects longer than is required can still experience higher memory usage than necessary, however once the final reference to an object is released the memory is available for garbage collection.
Trimolecular reaction Bimolecular reactions Molecularity > Bimolecular reactions In a bimolecular reaction, two molecules collide and exchange energy, atoms or groups of atoms.This can be described by the equation which corresponds to the second order rate law: d d t = − k r {\displaystyle {\frac {d}{dt}}=-k_{r}{\ce {}}} . Here, the rate of the reaction is proportional to the rate at which the reactants come together. An example of a bimolecular reaction is the SN2-type nucleophilic substitution of methyl bromide by hydroxide ion:
Quantum heat engines Quantum reciprocating heat engine and refrigerator Quantum_heat_engines_and_refrigerators > Quantum reciprocating heat engine and refrigerator In general when τ cyc ≫ 2 π / ω {\displaystyle \tau _{\text{cyc}}\gg 2\pi /\omega } the engine operates in quasi-adiabatic conditions. The only quantum effect can be found at low temperatures where the unit of energy of the device becomes ℏ ω {\displaystyle \hbar \omega } instead of k B T {\displaystyle k_{\text{B}}T} . The efficiency at this limit is η = 1 − ω c ω h {\displaystyle \eta =1-{\frac {\omega _{\text{c}}}{\omega _{\text{h}}}}} , always smaller than the Carnot efficiency η c {\displaystyle \eta _{\text{c}}} .
Latent inhibition Theories Latent_inhibition > Theories The LI effect has received a number of theoretical interpretations. One class of theory holds that inconsequential stimulus pre-exposure results in reduced associability for that stimulus. The loss of associability has been attributed to a variety of mechanisms that reduce attention, which then must be reacquired in order for learning to proceed normally. Alternatively, it has been proposed that LI is a result of retrieval failure rather than acquisition failure.
Markov algorithm Description Markov_algorithm > Description Then the algorithm terminates and the result of its work is considered to be R D S {\displaystyle RDS} . However, if this substitution formula is of the form L → D {\displaystyle L\to D} , then out of all of the possible representations of the string V ′ {\displaystyle V'} of the form of R L S {\displaystyle RLS} the one with the shortest R {\displaystyle R} is chosen, after which the string R D S {\displaystyle RDS} is considered to be the result of the current step, subject to further processing in the next step. For example, the process of applying the algorithm described above to the word \| ∗ \| \| {\displaystyle \|\|\|} results in the sequence of words \| b ∗ \| {\displaystyle \|b\|} , b a \| ∗ \| {\displaystyle ba\|\|} , a \| ∗ \| {\displaystyle a\|\|} , a \| b ∗ {\displaystyle a\|b} , a b a \| ∗ {\displaystyle aba\|} , b a a \| ∗ {\displaystyle baa\|} , a a \| ∗ {\displaystyle aa\|} , a a \| c {\displaystyle aa\|c} , a a c {\displaystyle aac} , a c \| {\displaystyle ac\|} and c \| \| {\displaystyle c\|\|} , after which the algorithm stops with the result \| \| {\displaystyle \|\|} .
Plato's problem Innate knowledge Plato's_problem > Plato (427 B.C. – 347 B.C.) > Meno > Innate knowledge Shortly before the demonstration of Pythagoras' theorem, the dialogue takes an epistemological turn when the interlocutors begin to discuss the fundamental nature of knowledge. The general question asked is how one can claim to know something when one does not even know what knowledge is. Via the Socratic method, it is shown that the answer to the question posed is innateness – one possesses a priori knowledge. This is derived from Socrates' belief that one's soul existed in past lives and knowledge is transferred from those lives to the current one. "These were revealed in a former state of existence, and are recovered by reminiscence (anamnesis) or association from sensible things" . The claim is that one does not need to know what knowledge is before gaining knowledge, but rather one has a wealth of knowledge before ever gaining any experience.
Compiling tools Types Compiling_tools > Types The C code generated by such a compiler is usually not intended to be readable and maintained by humans, so indent style and creating pretty C intermediate code are ignored. Some of the features of C that make it a good target language include the #line directive, which can be generated by the compiler to support debugging of the original source, and the wide platform support available with C compilers. While a common compiler type outputs machine code, there are many other types: Source-to-source compilers are a type of compiler that takes a high-level language as its input and outputs a high-level language.
Bisphenol S Effects on early development Bisphenol_S > Health effects > Effects on early development BPS exposure in the zebrafish model affected development of the hypothalamus and resulted in hyperactive behaviour. Studies in the Mouse model have shown that exposure to BPS significantly reduced the secretion of testosterone within the mouse fetal testes, with exposure to BPS in female mice also causing a significant fall in egg number, whilst also negatively affecting the quality of oocytes.Zebrafish and humans share 70% of the same genes that are expressed during development therefore, they are a useful model organism to understand the effects of BPS. Studies in the Zebrafish model have shown that parental exposure to BPS causes disrupted thyroid hormone levels in both the parental generation and F1 generation.
Tetrahedral intermediate Acetals and hemiacetals Tetrahedral_carbonyl_addition_compound > Stability of tetrahedral intermediates > Acetals and hemiacetals In the presence of acid, hemiacetals can undergo an elimination reaction, losing the oxygen atom that once belonged to the parent aldehyde’s carbonyl group. These oxonium ions are powerful electrophiles, and react rapidly with a second molecule of alcohol to form new, stable compounds, called acetals. The whole mechanism of acetal formation from hemiacetal is drawn below.
Error correction and detection Cyclic redundancy check Error_correction > Types of error detection > Cyclic redundancy check A cyclic redundancy check (CRC) is a non-secure hash function designed to detect accidental changes to digital data in computer networks. It is not suitable for detecting maliciously introduced errors. It is characterized by specification of a generator polynomial, which is used as the divisor in a polynomial long division over a finite field, taking the input data as the dividend. The remainder becomes the result.
Resonant transformer Variable differential transformer Pulse_transformer > Other types > Variable differential transformer A variable differential transformer is a rugged non-contact position sensor. It has two oppositely-phased primaries which nominally produce zero output in the secondary, but any movement of the core changes the coupling to produce a signal.

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