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Context-sensitive grammar Equivalence to linear bounded automaton Context-sensitive_grammar > Properties and uses > Equivalence to linear bounded automaton A formal language can be described by a context-sensitive grammar if and only if it is accepted by some linear bounded automaton (LBA). In some textbooks this result is attributed solely to Landweber and Kuroda. Others call it the Myhill–Landweber–Kuroda theorem. (Myhill introduced the concept of deterministic LBA in 1960.
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Response time (technology) Computing Pixel_response_time > Computing For a given request the service time varies little as the workload increases – to do X amount of work it always takes X amount of time. The wait time is how long the request had to wait in a queue before being serviced and it varies from zero, when no waiting is required, to a large multiple of the service time, as many requests are already in the queue and have to be serviced first. With basic queueing theory math you can calculate how the average wait time increases as the device providing the service goes from 0-100% busy.
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Percent point Summary Percent_point A percentage point or percent point is the unit for the arithmetic difference between two percentages. For example, moving up from 40 percent to 44 percent is an increase of 4 percentage points (although it is a 10-percent increase in the quantity being measured, if the total amount remains the same). In written text, the unit (the percentage point) is usually either written out, or abbreviated as pp or p.p. to avoid confusion with percentage increase or decrease in the actual quantity. After the first occurrence, some writers abbreviate by using just "point" or "points".
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Biological research Cellular respiration Biological_science > Cells > Cellular respiration At the end of the cycle, the total yield from 1 glucose (or 2 pyruvates) is 6 NADH, 2 FADH2, and 2 ATP molecules. Finally, the next stage is oxidative phosphorylation, which in eukaryotes, occurs in the mitochondrial cristae. Oxidative phosphorylation comprises the electron transport chain, which is a series of four protein complexes that transfer electrons from one complex to another, thereby releasing energy from NADH and FADH2 that is coupled to the pumping of protons (hydrogen ions) across the inner mitochondrial membrane (chemiosmosis), which generates a proton motive force.
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Instruction level parallelism Discussion Instruction-level_parallelism > Discussion Presently, a cache miss penalty to main memory costs several hundreds of CPU cycles. While in principle it is possible to use ILP to tolerate even such memory latencies, the associated resource and power dissipation costs are disproportionate.
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MiR-208 Summary MiR-208 miR-208 is a family of microRNA precursors found in animals, including humans. The ~22 nucleotide mature miRNA sequence is excised from the precursor hairpin by the enzyme Dicer. This sequence then associates with RISC which effects RNA interference.In humans, the gene for miR-208 is located in an intron of MYH7.
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Linear control Proportional control Linear_control > Proportional control Proportional control is a type of linear feedback control system in which a correction is applied to the controlled variable which is proportional to the difference between the desired value (SP) and the measured value (PV). Two classic mechanical examples are the toilet bowl float proportioning valve and the fly-ball governor. The proportional control system is more complex than an on–off control system but simpler than a proportional-integral-derivative (PID) control system used, for instance, in an automobile cruise control. On–off control will work for systems that do not require high accuracy or responsiveness but are not effective for rapid and timely corrections and responses.
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Storage Management Initiative – Specification Basic concepts Storage_Management_Initiative_–_Specification > Basic concepts In DMTF parlance, an SMI-S provider is an implementation for a specific profile or set of profiles. A subprofile describes a part of a management domain, and can be a common part in more than one profile.
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Oersted Stored energy Oersted > Definition > Stored energy The stored energy in a magnet, called magnet performance or maximum energy product (often abbreviated BHmax), is typically measured in units of megagauss-oersteds (MG⋅Oe).
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Waste heat Disposal Low_grade_heat > Disposal Low temperature heat contains very little capacity to do work (Exergy), so the heat is qualified as waste heat and rejected to the environment. Economically most convenient is the rejection of such heat to water from a sea, lake or river. If sufficient cooling water is not available, the plant can be equipped with a cooling tower or air cooler to reject the waste heat into the atmosphere. In some cases it is possible to use waste heat, for instance in district heating systems.
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Rasch model The Rasch model for measurement Rasch_model > Overview > The Rasch model for measurement Instead, the method of assessment should be changed so that this requirement is met, in the same way that a weighing scale should be rectified if it gives different comparisons between objects upon separate measurements of the objects. Data analysed using the model are usually responses to conventional items on tests, such as educational tests with right/wrong answers. However, the model is a general one, and can be applied wherever discrete data are obtained with the intention of measuring a quantitative attribute or trait.
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Zero-knowledge proof Zero-knowledge Zero-knowledge_proofs > Practical examples > Hamiltonian cycle for a large graph > Zero-knowledge Similarly, if Peggy knew in advance that Victor would ask to see the isomorphism then she could simply generate an isomorphic graph H (in which she also does not know a Hamiltonian cycle). Victor could simulate the protocol by himself (without Peggy) because he knows what he will ask to see. Therefore, Victor gains no information about the Hamiltonian cycle in G from the information revealed in each round.
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Our Friend the Atom Special Processes Our_Friend_the_Atom > Production team > Special Processes Ub Iwerks Eustace Lycett
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Spacecraft flight dynamics Powered flight Spacecraft_flight_dynamics > Powered flight The acceleration equation can be reduced from vector to scalar form by resolving it into its tangential (speed v {\displaystyle v} ) and angular (flight path angle θ {\displaystyle \theta } relative to local vertical) time rate-of-change components relative to the launch pad. The two equations thus become: where: F is the engine thrust; α is the angle of attack; m is the vehicle's mass; D is the vehicle's aerodynamic drag; L is its aerodynamic lift; r is the radial distance to the planet's center; and g is the gravitational acceleration at altitude.Mass decreases as propellant is consumed and rocket stages, engines or tanks are shed (if applicable). The planet-fixed values of v and θ at any time in the flight are then determined by numerical integration of the two rate equations from time zero (when both v and θ are 0): Finite element analysis can be used to integrate the equations, by breaking the flight into small time increments.
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Bonding-studenteninitiative e.V. Summary Bonding-studenteninitiative_e.V. Its aim is to develop students of engineering and natural sciences for professional life. This aim is mainly followed by the bonding-Firmenkontaktmesse (a job fair) which is organised every year at each location. Additionally, bonding organises company visits, company presentations, case studies, softskill trainings and more.
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Data fidelity Summary Database_integrity Data integrity is the maintenance of, and the assurance of, data accuracy and consistency over its entire life-cycle and is a critical aspect to the design, implementation, and usage of any system that stores, processes, or retrieves data. The term is broad in scope and may have widely different meanings depending on the specific context – even under the same general umbrella of computing. It is at times used as a proxy term for data quality, while data validation is a prerequisite for data integrity. Data integrity is the opposite of data corruption.
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Extensively drug-resistant tuberculosis Treatment Extensively_drug_resistant_tuberculosis > Treatment The principles of treatment for MDR-TB and for XDR-TB are the same. Second-line drugs are more toxic than the standard anti-TB regimen and can cause a range of serious side-effects including hepatitis, depression, hallucinations, and deafness. Patients are often hospitalized for long periods, in isolation. In addition, second-line drugs are extremely expensive compared with the cost of drugs for standard TB treatment.XDR-TB is associated with a much higher mortality rate than MDR-TB, because of a reduced number of effective treatment options.
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D. E. Marsh Patents D._E._Marsh > Patents GB191028252, published 30 November 1911, Improvements in and relating to systems and apparatus for washing out and filling locomotive boilers and the like
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Cluster of Differentiation Immunophenotyping Cluster_of_Differentiation > Immunophenotyping Two commonly used CD molecules are CD4 and CD8, which are, in general, used as markers for helper and cytotoxic T cells, respectively. These molecules are defined in combination with CD3+, as some other leukocytes also express these CD molecules (some macrophages express low levels of CD4; dendritic cells express high levels of CD8). Human immunodeficiency virus (HIV) binds CD4 and a chemokine receptor on the surface of a T helper cell to gain entry. The number of CD4 and CD8 T cells in blood is often used to monitor the progression of HIV infection.
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John von Neumann Cellular automata, DNA and the universal constructor John_von_Neumann > Computer science > Cellular automata, DNA and the universal constructor His "proof-of-principle" designs showed how it is logically possible, by using a general purpose programmable ("universal") constructor, to exhibit an indefinitely large class of self-replicators, spanning a wide range of complexity, interconnected by a network of potential mutational pathways, including pathways from the most simple to the most complex. This is an important result, as prior to that it might have been conjectured that there is a fundamental logical barrier to the existence of such pathways; in which case, biological organisms, which do support such pathways, could not be "machines", as conventionally understood. Von Neumann considers the potential for conflict between his self-reproducing machines, stating that "our models lead to such conflict situations", indicating it as a field of further study.
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History of genetic engineering Research and medicine Genetic_engineering_timeline > Research and medicine Targeting endogenous microRNA expression has allowed further fine tuning of gene expression, supplementing the more traditional gene knock out approach.Genetic engineering has been used to produce proteins derived from humans and other sources in organisms that normally cannot synthesize these proteins. Human insulin-synthesising bacteria were developed in 1979 and were first used as a treatment in 1982. In 1988 the first human antibodies were produced in plants. In 2000 Vitamin A-enriched golden rice, was the first food with increased nutrient value.
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Negative feedback loop Operational amplifier circuits Negative_feedback > Detailed implementations > Operational amplifier circuits Consequently, the voltage gain of the circuit in the diagram, assuming an ideal op amp, is the reciprocal of feedback voltage division ratio β: V out = R 1 + R 2 R 1 V in = 1 β V in {\displaystyle V_{\text{out}}={\frac {R_{\text{1}}+R_{\text{2}}}{R_{\text{1}}}}V_{\text{in}}\!={\frac {1}{\beta }}V_{\text{in}}\,} .A real op-amp has a high but finite gain A at low frequencies, decreasing gradually at higher frequencies. In addition, it exhibits a finite input impedance and a non-zero output impedance. Although practical op-amps are not ideal, the model of an ideal op-amp often suffices to understand circuit operation at low enough frequencies. As discussed in the previous section, the feedback circuit stabilizes the closed-loop gain and desensitizes the output to fluctuations generated inside the amplifier itself.
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Model-based reasoning Reasoning with declarative models Model-based_reasoning > Reasoning with declarative models From a more practical perspective, a declarative model means, that the system is simulated with a game engine. A game engine takes a feature as input value and determines the output signal. Sometimes, a game engine is described as a prediction engine for simulating the world.
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Non-communicable diseases Chronic respiratory disease Non-communicable_diseases > Key diseases > Chronic respiratory disease Chronic Respiratory Diseases (CRDs) are diseases of the lungs and airways. According to the World Health Organization (WHO) hundreds of millions of people have CRDs. Common CRDs are: Asthma, Chronic obstructive pulmonary disease, Occupational lung disease, and Pulmonary hypertension. While CRDs are not curable, various treatments are available to help improve quality of life for individuals who have them.
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Shattered assumptions theory The self is worthy Shattered_assumptions_theory > Basic assumptions > The self is worthy The final fundamental assumption evaluates one's self as a positive, moral, and decent--and thus deserving of good outcomes in life. Individuals' assessment of their self-worth contributes to their success in life. A person's positive self-worth encourages them to be effective in their tasks at hand. Generally, this assumption enables an individual to maintain a belief that s/he has the ability to control positive or negative outcomes.
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Distributed operating system Coherent memory abstraction Distributed_operating_system > History > Foundational work > Coherent memory abstraction Algorithms for scalable synchronization on shared-memory multiprocessors
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Specific volume Summary Specific_volume In thermodynamics, the specific volume of a substance (symbol: ν, nu) is a mass-specific intrinsic property of the substance, defined as the quotient of the substance's volume (V) to its mass (m). It is the reciprocal of density ρ (rho) and it is also related to the molar volume and molar mass: ν = V m = ρ − 1 = V ~ M {\displaystyle \nu ={\frac {V}{m}}=\rho ^{-1}={\frac {\tilde {V}}{M}}} The standard unit of specific volume is cubic meters per kilogram (m3/kg), but other units include ft3/lb, ft3/slug, or mL/g.Specific volume for an ideal gas is related to the molar gas constant (R) and the gas's temperature (T), pressure (P), and molar mass (M) as shown: Since P V = n R T {\displaystyle PV={nRT}} and n = m M {\textstyle n={\frac {m}{M}}} ν = V m = R T P M {\displaystyle \nu ={\frac {V}{m}}={\frac {RT}{PM}}}
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Permanent gas Physical characteristics Permanent_gas > Physical characteristics Gaseous compounds with polar covalent bonds contain permanent charge imbalances and so experience relatively strong intermolecular forces, although the molecule while the compound's net charge remains neutral. Transient, randomly induced charges exist across non-polar covalent bonds of molecules and electrostatic interactions caused by them are referred to as Van der Waals forces. The interaction of these intermolecular forces varies within a substance which determines many of the physical properties unique to each gas.
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Automath Overview Automath > Overview Propositions were represented as sets (called "categories") of their proofs, and the question of provability became a question of non-emptiness (type inhabitation); de Bruijn was unaware of Howard's work, and stated the correspondence independently.L. S. van Benthem Jutting, as part of this Ph.D. thesis in 1976, translated Edmund Landau's Foundations of Analysis into Automath and checked its correctness. Automath was never widely publicized at the time, however, and so never achieved widespread use; nonetheless, it proved very influential in the later development of logical frameworks and proof assistants. The Mizar system, a system of writing and checking formalized mathematics that is still in active use, was influenced by Automath.
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Scale (social sciences) Non-comparative scaling techniques Scale_(social_sciences) > Non-comparative scaling techniques Visual analogue scale (also called the Continuous rating scale and the graphic rating scale) – respondents rate items by placing a mark on a line. The line is usually labeled at each end. There are sometimes a series of numbers, called scale points, (say, from zero to 100) under the line. Scoring and codification is difficult for paper-and-pencil scales, but not for computerized and Internet-based visual analogue scales.
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Regenerative variable-frequency drives AC line harmonics Variable-frequency_drive > Application considerations > AC line harmonics Note of clarification:.While harmonics in the PWM output can easily be filtered by carrier-frequency-related filter inductance to supply near-sinusoidal currents to the motor load, the VFD's diode-bridge rectifier converts AC line voltage to DC voltage output by super-imposing non-linear half-phase current pulses thus creating harmonic current distortion, and hence voltage distortion, of the AC line input. When the VFD loads are relatively small in comparison to the large, stiff power system available from the electric power company, the effects of VFD harmonic distortion of the AC grid can often be within acceptable limits. Furthermore, in low-voltage networks, harmonics caused by single-phase equipment such as computers and TVs are partially cancelled by three-phase diode bridge harmonics because their 5th and 7th harmonics are in counterphase. However, when the proportion of VFD and other non-linear load compared to total load or of non-linear load compared to the stiffness at the AC power supply, or both, is relatively large enough, the load can have a negative impact on the AC power waveform available to other power company customers in the same grid.
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Language of thought Connection to connectionism Language_of_thought > Connection to connectionism Connectionism is an approach to artificial intelligence that often accepts a lot of the same theoretical framework that LOTH accepts, namely that mental states are computational and causally efficacious and very often that they are representational. However, connectionism stresses the possibility of thinking machines, most often realized as artificial neural networks, an inter-connectional set of nodes, and describes mental states as able to create memory by modifying the strength of these connections over time. Some popular types of neural networks are interpretations of units, and learning algorithm. "Units" can be interpreted as neurons or groups of neurons.
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Blackbody temperature Stars and planets Black_body_radiator > Realizations > Stars and planets Changes in the core lead to changes in the supply of energy to the photosphere, but such changes are slow on the time scale of interest here. Assuming these circumstances can be realized, the outer layer of the star is somewhat analogous to the example of an enclosure with a small hole in it, with the hole replaced by the limited transmission into space at the outside of the photosphere. With all these assumptions in place, the star emits black-body radiation at the temperature of the photosphere.
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Medium Girder Bridge Configurations and deployment Medium_Girder_Bridge > Configurations and deployment The primary components of the MGB system are rectangular "top deck" segments, and triangular bracing "bottom deck" segments. All segments are man portable. Short/low load bridges can be constructed using just top deck components.
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Pentode transistor Modern pentode transistors Pentode_transistor > Modern pentode transistors Triple emitter transistor in three input transistor-transistor logic gates. Triple collector transistor in three output integrated injection logic gates. Field effect transistor having three gates. == References ==
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Cis effect Ligands effects on CO cis-labilization Cis_effect > Ligands effects on CO cis-labilization The order of ligands which possess cis-labilizing effects are as follows: CO, AuPPh3, H−, SnPh3, GePh3, M(CO)n < P(O)Ph3 < PPh3 < I− < CH3SO2−, NC5H5 < CH3CO < Br−, NCO− < Cl− < NO3− Anionic ligands such as F−, Cl−, OH−, and SH− have particularly strong CO labilizing effects in − complexes. This is because these ligands will stabilize the 16 e− intermediate by electron donation from the p-pi lone pair donor orbital. Other sulfur-containing ligands, particularly thiobenzoate, are other examples of particularly useful CO cis-labilizing ligands, which can be explained by stabilization of the intermediate that results upon CO dissociation. This can be attributed to the partial interaction of the oxygen from the thiobenzoate and the metal, which can eliminate solvent effects that can occur during ligand dissociation in transition metal complexes.Note that the strongest labilizing effects come from ligands that are weak sigma donors with virtually no pi-accepting behavior.
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Ivermectin COVID-19 Ivermectin > Research > COVID-19 During the COVID-19 pandemic, ivermectin was researched for possible utility in preventing and treating COVID-19, but no good evidence of benefit was found.
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Wave spectrum Models Sea_wave > Models Surfers are very interested in the wave forecasts. There are many websites that provide predictions of the surf quality for the upcoming days and weeks. Wind wave models are driven by more general weather models that predict the winds and pressures over the oceans, seas, and lakes. Wind wave models are also an important part of examining the impact of shore protection and beach nourishment proposals.
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Global heating Clean energy Man-made_climate_change > Reducing and recapturing emissions > Clean energy Wind and solar also produce energy intermittently and with seasonal variability. Traditionally, hydro dams with reservoirs and conventional power plants have been used when variable energy production is low. Going forward, battery storage can be expanded, energy demand and supply can be matched, and long-distance transmission can smooth variability of renewable outputs.
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Host tropism Human immunodeficiency virus (HIV) Host_tropism > Viral tropism > Human immunodeficiency virus (HIV) The human immunodeficiency virus exhibits host tropism for CD4 related immune cells (e.g. T helper cells, macrophages or dendritic cells). These cells express a CD4 receptor, to which HIV can bind, through the gp120 and gp41 proteins on its surface. HIV also requires a second co-receptor along with the CD4-gp120 complex to enter the target cells - either CCR5 or CXCR4.
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A¹ homotopy theory Construction A1_homotopy_theory > Construction These were not available in the 90's and the original definition passes by way of Quillen's theory of model categories. Another way of seeing the situation is that Morel-Voevodsky's original definition produces a concrete model for (the homotopy category of) the infinity category H ( S ) {\displaystyle {\mathcal {H}}(S)} . This more concrete construction is sketched below.
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Attention (machine learning) A language translation example Attention_(machine_learning) > A language translation example This view of the attention weights addresses the neural network "explainability" problem. Networks that perform verbatim translation without regard to word order would show the highest scores along the (dominant) diagonal of the matrix. The off-diagonal dominance shows that the attention mechanism is more nuanced.
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Shoulder surfing (computer security) Gaze-based password entry Shoulder_surfing_(computer_security) > Countermeasures > Gaze-based password entry State of the art eye trackers offers non-encumbering, remote video-based eye tracking with an accuracy of 1˚ of visual angle. Eye trackers are a specialized application of computer vision. A camera is used to monitor the user's eyes.
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Epithelial membrane antigen Promoting tumor invasion Mucin_short_variant_S1 > Role in cancer > Promoting tumor invasion Studies have demonstrated that MUC1 is phosphorylated on a YEKV motif. Phosphorylation of this site has been demonstrated by LYN through mediation of interleukin 7, Src through mediation of EGFR, and PRKCD. This interaction is antagonized by degradation of beta-catenin by GSK3B.
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Forensic botany DNA analysis Forensic_biology > Disciplines > DNA analysis DNA, or deoxyribonucleic acid, is one of the most popular pieces of evidence to recover at a crime scene. More often than not, evidence containing DNA is regarded to as biological evidence. With all of the substantial advances that have been made regarding DNA, biological evidence is recognized to be the "golden standard" in forensic science.At the scene, biological evidence must be initially visibly recognized. Sometimes this is not always possible and the aid of an alternative light source, or Advanced Light Source (ALS), is required.
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Lean Manufacturing Summary Just-in-time_manufacturing Lean manufacturing is a production method aimed primarily at reducing times within the production system as well as response times from suppliers and to customers. It is closely related to another concept called just-in-time manufacturing (JIT manufacturing in short). Just-in-time manufacturing tries to match production to demand by only supplying goods which have been ordered and focuses on efficiency, productivity (with a commitment to continuous improvement) and reduction of "wastes" for the producer and supplier of goods. Lean manufacturing adopts the just-in-time approach and additionally focuses on reducing cycle, flow and throughput times by further eliminating activities which do not add any value for the customer.
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HT-TALENS AIDS HT-TALENS > AIDS The HIV genome is made from RNA rather than DNA. The enzyme that converts RNA to DNA and then inserts it into a cell makes between one and 10 mistakes every time it copies itself. This high error rate means that the virus population that inhabits each HIV patients is genetically diverse.When the HIV virus infects someone, it copies its DNA and inserts into the DNA of white blood cells, making the virus part of its host. Even if these genes could be silenced with drugs, (later) stopping the drugs sets the viral DNA free to attack the patient.HT-TALENs binds to that sequence and cuts the HIV DNA, but not human DNA. When that cut gets fixed by the cell's DNA repair system, it makes a scar that leaves the virus unable to return and make HIV DNA cells. 60% of the cells making the protein damage the viral DNA.
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P orbitals Hydrogen-like orbitals 1s_electron > Hydrogen-like orbitals (see hydrogen atom). For atoms with two or more electrons, the governing equations can be solved only with the use of methods of iterative approximation.
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Small nucleolar RNA SNORA52 Summary Small_nucleolar_RNA_SNORA52 In molecular biology, Small nucleolar RNA SNORA52 (also known as ACA52) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a 'guide RNA'.
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Chemical Formula Summary Chemical_constitution For reasons of structural complexity, a single condensed chemical formula (or semi-structural formula) may correspond to different molecules, known as isomers. For example, glucose shares its molecular formula C6H12O6 with a number of other sugars, including fructose, galactose and mannose. Linear equivalent chemical names exist that can and do specify uniquely any complex structural formula (see chemical nomenclature), but such names must use many terms (words), rather than the simple element symbols, numbers, and simple typographical symbols that define a chemical formula. Chemical formulae may be used in chemical equations to describe chemical reactions and other chemical transformations, such as the dissolving of ionic compounds into solution. While, as noted, chemical formulae do not have the full power of structural formulae to show chemical relationships between atoms, they are sufficient to keep track of numbers of atoms and numbers of electrical charges in chemical reactions, thus balancing chemical equations so that these equations can be used in chemical problems involving conservation of atoms, and conservation of electric charge.
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Memory recall Neuroanatomy Cued_recall > Neuroanatomy The anterior cingulate cortex, globus pallidus, thalamus, and cerebellum show higher activation during recall than during recognition which suggests that these components of the cerebello-frontal pathway play a role in recall processes that they do not in recognition. Although recall and recognition are considered separate processes, they are both most likely constitute components of distributed networks of brain regions. According to neuroimaging data, PET studies on recall and recognition have consistently found increases in regional cerebral blood flow (RCBF) in the following six brain regions: (1) the prefrontal cortex, particularly on the right hemisphere; (2) the hippocampal and parahippocampal regions of the medial temporal lobe; (3) the anterior cingulate cortex; (4) the posterior midline area that includes posterior cingulate, retrosplenial (see retrosplenial region), precuneus, and cuneus regions; (5) the inferior parietal cortex, especially on the right hemisphere; and (6) the cerebellum, particularly on the left. The specific role of each of the six main regions in episodic retrieval is still unclear, but some ideas have been suggested.
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Biochemical analysis Relationship to other "molecular-scale" biological sciences Biochemical_Processes > Relationship to other "molecular-scale" biological sciences Genetics is the study of the effect of genetic differences in organisms. This can often be inferred by the absence of a normal component (e.g. one gene). The study of "mutants" – organisms that lack one or more functional components with respect to the so-called "wild type" or normal phenotype.
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DNS over TLS Summary DNS_over_TLS DNS over TLS (DoT) is a network security protocol for encrypting and wrapping Domain Name System (DNS) queries and answers via the Transport Layer Security (TLS) protocol. The goal of the method is to increase user privacy and security by preventing eavesdropping and manipulation of DNS data via man-in-the-middle attacks. The well-known port number for DoT is 853. While DNS-over-TLS is applicable to any DNS transaction, it was first standardized for use between stub or forwarding resolvers and recursive resolvers, in RFC 7858 in May of 2016. Subsequent IETF efforts specify the use of DoT between recursive and authoritative servers ("Authoritative DNS-over-TLS" or "ADoT") and a related implementation between authoritative servers (Zone Transfer-over-TLS or "xfr-over-TLS").
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List of HTTP header fields Avoiding caching HTTP_headers > Effects of selected fields > Avoiding caching The Pragma: no-cache header field, defined in the HTTP/1.0 spec, has the same purpose. It, however, is only defined for the request header. Its meaning in a response header is not specified. The behavior of Pragma: no-cache in a response is implementation specific. While some user agents do pay attention to this field in responses, the HTTP/1.1 RFC specifically warns against relying on this behavior.
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Intermembrane space of mitochondria Organization and distribution Intermembrane_space_of_mitochondria > Organization and distribution Often, they form a complex 3D branching network inside the cell with the cytoskeleton. The association with the cytoskeleton determines mitochondrial shape, which can affect the function as well: different structures of the mitochondrial network may afford the population a variety of physical, chemical, and signalling advantages or disadvantages. Mitochondria in cells are always distributed along microtubules and the distribution of these organelles is also correlated with the endoplasmic reticulum. Recent evidence suggests that vimentin, one of the components of the cytoskeleton, is also critical to the association with the cytoskeleton.
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Weller's theorem Example Weller's_theorem > Example This range does not contain the ratio 1:4, hence the fixed point is not here. If the ratio is between 1:4 and 9:6, then the entire vanilla should be given to George and the entire chocolate should be given to Alice. The ratio of values is 9:4, which is not in the range, so the fixed point is not found yet.
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Outlier detection Popular techniques Anomaly_detection > Popular techniques Many anomaly detection techniques have been proposed in literature. Some of the popular techniques are: Statistical (Z-score, Tukey's range test and Grubbs's test) Density-based techniques (k-nearest neighbor, local outlier factor, isolation forests, and many more variations of this concept) Subspace-, correlation-based and tensor-based outlier detection for high-dimensional data One-class support vector machines Replicator neural networks, autoencoders, variational autoencoders, long short-term memory neural networks Bayesian networks Hidden Markov models (HMMs) Minimum Covariance Determinant Clustering: Cluster analysis-based outlier detection Deviations from association rules and frequent itemsets Fuzzy logic-based outlier detection Ensemble techniques, using feature bagging, score normalization and different sources of diversityThe performance of methods depends on the data set and parameters, and methods have little systematic advantages over another when compared across many data sets and parameters.
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Differential privacy The Laplace mechanism Differential_privacy > ε-differentially private mechanisms > The Laplace mechanism For example, assume we have a database of medical records D 1 {\displaystyle D_{1}} where each record is a pair (Name, X), where X {\displaystyle X} is a Boolean denoting whether a person has diabetes or not. For example: Now suppose a malicious user (often termed an adversary) wants to find whether Chandler has diabetes or not. Suppose he also knows in which row of the database Chandler resides.
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Bus encryption Summary Bus_encryption Bus encryption is the use of encrypted program instructions on a data bus in a computer that includes a secure cryptoprocessor for executing the encrypted instructions. Bus encryption is used primarily in electronic systems that require high security, such as automated teller machines, TV set-top boxes, and secure data communication devices such as two-way digital radios. Bus encryption can also mean encrypted data transmission on a data bus from one processor to another processor. For example, from the CPU to a GPU which does not require input of encrypted instructions.
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Screw (simple machine) Frictionless mechanical advantage Screw_(simple_machine) > Frictionless mechanical advantage The mechanical advantage MA of a screw is defined as the ratio of axial output force Fout applied by the shaft on a load to the rotational force Fin applied to the rim of the shaft to turn it. For a screw with no friction (also called an ideal screw), from conservation of energy the work done on the screw by the input force turning it is equal to the work done by the screw on the load force: W i n = W o u t {\displaystyle W_{in}=W_{out}\,} Work is equal to the force multiplied by the distance it acts, so the work done in one complete turn of the screw is W i n = 2 π r F i n {\displaystyle W_{in}=2\pi rF_{in}\,} and the work done on the load is W o u t = l F o u t {\displaystyle W_{out}=lF_{out}\,} . So the ideal mechanical advantage of a screw is equal to the distance ratio: It can be seen that the mechanical advantage of a screw depends on its lead, l {\displaystyle l\,} . The smaller the distance between its threads, the larger the mechanical advantage, and the larger the force the screw can exert for a given applied force. However most actual screws have large amounts of friction and their mechanical advantage is less than given by the above equation.
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Binding immunoglobulin protein Neurodegenerative disease Binding_immunoglobulin_protein > Clinical significance > Neurodegenerative disease As an ER chaperone protein, BiP prevents neuronal cell death induced by ER stress by correcting misfolded proteins. Moreover, a chemical inducer of BiP, named BIX, reduced cerebral infarction in cerebral ischemic mice. Conversely, enhanced BiP chaperone function has been strongly implicated in Alzheimer's disease.
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Sine rule Summary Law_of_sines In trigonometry, the law of sines, sine law, sine formula, or sine rule is an equation relating the lengths of the sides of any triangle to the sines of its angles. According to the law, where a, b, and c are the lengths of the sides of a triangle, and α, β, and γ are the opposite angles (see figure 2), while R is the radius of the triangle's circumcircle. When the last part of the equation is not used, the law is sometimes stated using the reciprocals; The law of sines can be used to compute the remaining sides of a triangle when two angles and a side are known—a technique known as triangulation. It can also be used when two sides and one of the non-enclosed angles are known.
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Biosand filter During the run Biosand_filter > Filtration process > During the run It provides the oxygen required by the microorganisms in the biofilm. Large suspended particles and pathogens are trapped in the top of the sand and partially plug the pore spaces between the sand grains. This causes the flow rate to decrease.
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Psychic numbing Neuropsychophysiology Psychic_numbing > Neuroscience > Neuropsychophysiology Cortisol helps regulate the stress response via the negative feedback loop, which are activated when a person is subjected to specific situations that trigger the relationship between the emotionally charged memories of the traumatic event and the observable autonomic responses.Stress can also be considered a brain-body reaction due to external or internal cues this can include the environment as well as memory. The areas of the brain that communicate with one another are the prefrontal cortex, amygdala, hippocampus, nucleus accumbens, and the hypothalamus. Through a series of feedback processes, the release of specific neurotransmitters as well as neuromodulators occurs. Norepinephrine (NE) is released by the Locus coeruleus, it is then transferred to the limbic system where much of the memory consolidation and fight or flight responses are facilitated.
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Statistical data type Simple data types Statistical_data_type > Simple data types The following table classifies the various simple data types, associated distributions, permissible operations, etc. Regardless of the logical possible values, all of these data types are generally coded using real numbers, because the theory of random variables often explicitly assumes that they hold real numbers.
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Motor skill Components of development Motor_skill > Development > Components of development Growth – increase in the size of the body or its parts as the individual progresses toward maturity (quantitative structural changes) Maturation – refers to qualitative changes that enable one to progress to higher levels of functioning; it is primarily innate Experience or learning – refers to factors within the environment that may alter or modify the appearance of various developmental characteristics through the process of learning Adaptation – refers to the complex interplay or interaction between forces within the individual (nature) and the environment (nurture)
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Climate apocalypse Potential attempts to revert a started apocalypse Climate_apocalypse > Potential attempts to revert a started apocalypse Grist advised that although some people describe an expectation of a horrible climate apocalypse, the effects of climate change could be lessened or worsened depending upon when a coordinated response to lessen the damage develops.KQED reported that the scientific consensus is to take whatever action possible, wherever possible, even when there are reports of a coming climate apocalypse.Scientists commenting in The Atlantic said that the Representative Concentration Pathway was an important measurement to watch, and that as of 2018 this measurement predicts a worst-case scenario for the world.Stratospheric aerosol injection, a hypothetical process for blocking sunlight from the earth, is proposed as a desperate technological response (see also #Global dimming) to reduce existential risk which comes with many risks and is opposed by many scientists.
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Isotope dilution Applications Isotopic_dilution > Applications Isotope dilution is almost exclusively employed with mass spectrometry in applications where high-accuracy is demanded. For example, all National Metrology Institutes rely significantly on isotope dilution when producing certified reference materials. In addition to high-precision analysis, isotope dilution is applied when low recovery of the analyte is encountered. In addition to the use of stable isotopes, radioactive isotopes can be employed in isotope dilution which is often encountered in biomedical applications, for example, in estimating the volume of blood.
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Rotational viscosity Summary Rotational_viscosity Viscosity is usually described as the property of a fluid which determines the rate at which local momentum differences are equilibrated. Rotational viscosity is a property of a fluid which determines the rate at which local angular momentum differences are equilibrated. In the classical case, by the equipartition theorem, at equilibrium, if particle collisions can transfer angular momentum as well as linear momentum, then these degrees of freedom will have the same average energy. If there is a lack of equilibrium between these degrees of freedom, then the rate of equilibration will be determined by the rotational viscosity coefficient.
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Soil thermal properties Uses Soil_thermal_properties > Uses The thermal inertia of the soil enables the ground to be used for underground thermal energy storage. Solar energy can be recycled from summer to winter by using the ground as a long term store of heat energy before being retrieved by ground source heat pumps in winter. Changes in the amount of dissolved organic carbon and soil organic carbon within soil can effect its ability to respirate, either increasing or decreasing the soils carbon uptake.Furthermore, MCS design criteria for shallow loop ground source heat pumps require an accurate in situ thermal conductivity reading. This can be done by using the above-mentioned thermal heat probe to accurately determine soil thermal conductivity across the site.
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Power electronics Single-phase half-bridge inverter Power_electronics > DC/AC converters (inverters) > Single-phase half-bridge inverter The switching scheme requires that both S+ and S- be on for a half cycle of the AC output period. The fundamental AC output amplitude is equal to vo1 = vaN = 2vi/π . Its harmonics have an amplitude of voh = vo1/h.
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Enzyme-substrate complex Substrate presentation Enzyme > Mechanism > Substrate presentation Substrate presentation is a process where the enzyme is sequestered away from its substrate. Enzymes can be sequestered to the plasma membrane away from a substrate in the nucleus or cytosol. Or within the membrane, an enzyme can be sequestered into lipid rafts away from its substrate in the disordered region.
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Procedurally generated terrain Summary Procedurally_generated_terrain A scenery generator is software used to create landscape images, 3D models, and animations. These programs often use procedural generation to generate the landscapes. If not using procedural generation to create the landscapes, then normally a 3D artist would render and create the landscapes.
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Spacetime geometry Twin paradox Spacetime_Interval > Spacetime in special relativity > Mutual time dilation and the twin paradox > Twin paradox Figs. 2-6 and 2-11 illustrate the concept of lines (planes) of simultaneity: Lines parallel to the observer's x-axis (xy-plane) represent sets of events that are simultaneous in the observer frame. In Fig. 2-11, the blue lines connect events on Terence's world line which, from Stella's point of view, are simultaneous with events on her world line.
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Glucocorticoid remediable aldosteronism Treatment Glucocorticoid_remediable_aldosteronism > Treatment In GRA, the hypersecretion of aldosterone and the accompanying hypertension are remedied when ACTH secretion is suppressed by administering glucocorticoids.Dexamethasone, spironolactone and eplerenone have been used in treatment.
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Root of an equation Overview Solving_equations > Overview One general form of an equation is f ( x 1 , … , x n ) = c , {\displaystyle f\left(x_{1},\dots ,x_{n}\right)=c,} where f is a function, x1, ..., xn are the unknowns, and c is a constant. Its solutions are the elements of the inverse image f − 1 ( c ) = { ( a 1 , … , a n ) ∈ D ∣ f ( a 1 , … , a n ) = c } , {\displaystyle f^{-1}(c)={\bigl \{}(a_{1},\dots ,a_{n})\in D\mid f\left(a_{1},\dots ,a_{n}\right)=c{\bigr \}},} where D is the domain of the function f. The set of solutions can be the empty set (there are no solutions), a singleton (there is exactly one solution), finite, or infinite (there are infinitely many solutions). For example, an equation such as 3 x + 2 y = 21 z , {\displaystyle 3x+2y=21z,} with unknowns x, y and z, can be put in the above form by subtracting 21z from both sides of the equation, to obtain 3 x + 2 y − 21 z = 0 {\displaystyle 3x+2y-21z=0} In this particular case there is not just one solution, but an infinite set of solutions, which can be written using set builder notation as { ( x , y , z ) ∣ 3 x + 2 y − 21 z = 0 } . {\displaystyle {\bigl \{}(x,y,z)\mid 3x+2y-21z=0{\bigr \}}.}
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Central heating Overview Central_heating > Overview A furnace burns fuel oil or gas, which heats air in a heat exchanger, and blower fans circulate the warmed air through a network of ducts to the rooms in the building. This system is cheaper because the air moves through a series of ducts instead of pipes, and does not require a pipe fitter to install. The space between floor joists can be boxed in and used as some of the ductwork, further lowering costs.
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Statistical learning Supervised learning Machine_learning_algorithm > Approaches > Supervised learning Through iterative optimization of an objective function, supervised learning algorithms learn a function that can be used to predict the output associated with new inputs. An optimal function will allow the algorithm to correctly determine the output for inputs that were not a part of the training data. An algorithm that improves the accuracy of its outputs or predictions over time is said to have learned to perform that task.Types of supervised-learning algorithms include active learning, classification and regression.
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Nuclide Types of nuclides Nuclide > Types of nuclides Nuclear isomers are members of a set of nuclides with equal proton number and equal mass number (thus making them by definition the same isotope), but different states of excitation. An example is the two states of the single isotope 9943Tc shown among the decay schemes. Each of these two states (technetium-99m and technetium-99) qualifies as a different nuclide, illustrating one way that nuclides may differ from isotopes (an isotope may consist of several different nuclides of different excitation states).
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Sources of electrical energy Friction Sources_of_electrical_energy > Friction Its main application is in Van de Graaff generators, used to produce high voltages in order to test the dielectric strength of insulating materials. Other uses are in electrostatic painting and sandpaper manufacturing. The course grains acquire a negative charge as they move across the negative plate. As unlike charges attract, the positive plate attracts the course grains and their impact velocity enables them to be embedded into the adhesive.
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Stack machines Out-of-order execution Stack_machines > Comparison with register machines > Out-of-order execution One issue brought up in the research was that it takes about 1.88 stack-machine instructions to do the work of one instruction on a load-store architecture machine. Competitive out-of-order stack machines therefore require about twice as many electronic resources to track instructions ("issue stations"). This might be compensated by savings in instruction cache and memory and instruction decoding circuits.
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Effective field theories The renormalization group Effective_field_theory > The renormalization group The construction of an effective field theory accurate to some power of 1/M requires a new set of free parameters at each order of the expansion in 1/M. This technique is useful for scattering or other processes where the maximum momentum scale k satisfies the condition k/M≪1. Since effective field theories are not valid at small length scales, they need not be renormalizable. Indeed, the ever expanding number of parameters at each order in 1/M required for an effective field theory means that they are generally not renormalizable in the same sense as quantum electrodynamics which requires only the renormalization of two parameters.
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Paravertebral ganglia Sympathetic chain ganglia Sympathetic_ganglion > Structure > Sympathetic chain ganglia The postganglionic neurons extend across most of the body.Upon exiting the sympathetic chain, the fibres enter a less-myelinated gray ramus communicans. There is still a myelin sheath present – just in far lower amounts compared to the white ramus communicans. This ramus then enters the spinal nerve and is sent to its synapsing target, or becomes a visceral branch to enter a plexus (e.g. the superficial or deep cardiac plexuses), or synapses directly onto a target.
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Wee1 Introduction Wee1 > Introduction It is a kinase determining the timepoint of entry into mitosis, thus influencing the size of the daughter cells. Loss of Wee1 function will produce smaller than normal daughter cell, because cell division occurs prematurely. Its name is derived from the Scottish dialect word wee, meaning small - its discoverer Paul Nurse was working at the University of Edinburgh in Scotland at the time of discovery.
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Creatine Parkinson's disease Creatine > Research > Mitochondrial diseases > Parkinson's disease Creatine's impact on mitochondrial function has led to research on its efficacy and safety for slowing Parkinson's disease. As of 2014, the evidence did not provide a reliable foundation for treatment decisions, due to risk of bias, small sample sizes, and the short duration of trials.
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Edge cloud Privacy and security Edge_cloud > Concept > Privacy and security The distributed nature of this paradigm introduces a shift in security schemes used in cloud computing. In edge computing, data may travel between different distributed nodes connected through the Internet and thus requires special encryption mechanisms independent of the cloud. Edge nodes may also be resource-constrained devices, limiting the choice in terms of security methods.
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Eukaryotic chromosome structure Nucleosomes Eukaryotic_chromosome_structure > Nucleosomes The nucleosome is the basic unit of DNA condensation and consists of a DNA double helix bound to an octamer of core histones (2 dimers of H2A and H2B, and an H3/H4 tetramer). About 147 base pairs of DNA coil around 1 octamer, and ~20 base pairs are sequestered by the addition of the linker histone (H1), and various length of "linker" DNA (~0-100 bp) separate the nucleosomes. The spacing of nucleosomes along DNA results in a “beads on a string” appearance. Histone modification controls the accessibility to DNA. Histone acetyltransferases or HATs acetylate residues on the histone tail leading to increased accessibility to DNA.
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Axiom schema of specification Relation to the axiom schema of replacement Axiom_schema_of_specification > Relation to the axiom schema of replacement But in this case, the set B required for the axiom of separation is the empty set, so the axiom of separation follows from the axiom of replacement together with the axiom of empty set. For this reason, the axiom schema of specification is often left out of modern lists of the Zermelo–Fraenkel axioms. However, it's still important for historical considerations, and for comparison with alternative axiomatizations of set theory, as can be seen for example in the following sections.
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Web traffic From search engines Web_traffic > Sources > From search engines When a user clicks on one of the listings in the search results, they are directed to the corresponding website and data is transferred from the website's server, thus counting the visitors towards the overall flow of traffic to that website. Search engine optimization (SEO), is the ongoing practice of optimizing a website to help improve its rankings in the search engines. Several internal and external factors are involved which can help improve a site's listing within the search engines. The higher a site ranks within the search engines for a particular keyword, the more traffic it will receive.
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Malthusian parameter Summary Malthusian_growth_model Among mankind, misery and vice. " A model of population growth bounded by resource limitations was developed by Pierre Francois Verhulst in 1838, after he had read Malthus' essay. Verhulst named the model a logistic function.
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Enteric coating Description Enteric_coating > Description Although some studies indicated that larger sized dosage forms may require additional time for gastric emptying, others suggested that the size, shape, or volume of the tablet possess no significant effects instead. Enteric coated granules emptying rate is, however, less affected by the presence of food and present the more uniform release and reproducible transit time typical of the multiparticulates dispersion.By preventing the drug from dissolving into the stomach, enteric coating may protect gastric mucosa from the irritating effects of the medication itself. When the drug reaches the neutral or alkaline environment of the intestine, its active ingredients can then dissolve and become available for absorption into the bloodstream.
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Linear Regression Estimation methods Linear_Regression > Estimation methods A large number of procedures have been developed for parameter estimation and inference in linear regression. These methods differ in computational simplicity of algorithms, presence of a closed-form solution, robustness with respect to heavy-tailed distributions, and theoretical assumptions needed to validate desirable statistical properties such as consistency and asymptotic efficiency. Some of the more common estimation techniques for linear regression are summarized below.
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Chemical Kinetics Pressure Reaction_kinetics > Factors affecting reaction rate > Pressure Condensed-phase rate coefficients can also be affected by pressure, although rather high pressures are required for a measurable effect because ions and molecules are not very compressible. This effect is often studied using diamond anvils. A reaction's kinetics can also be studied with a pressure jump approach. This involves making fast changes in pressure and observing the relaxation time of the return to equilibrium.
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Hypothalamic-pituitary-adrenal axis Early life stress HPA_axis > Stress > Stress and development > Early life stress There may be a critical period during development during which the level of stress hormones in the bloodstream contribute to the permanent calibration of the HPA axis. One experiment has shown that, even in the absence of any environmental stressors, early-life exposure to moderate levels of corticosterone was associated with stress resilience in adult rats, whereas exposure to high doses was associated with stress vulnerability.Another possibility is that the effects of early-life stress on HPA functioning are mediated by maternal care. Frequent human handling of the rat pups may cause their mother to exhibit more nurturant behavior, such as licking and grooming.
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Diophantine equation Typical questions Diophantine_equation > Diophantine analysis > Typical questions The questions asked in Diophantine analysis include: Are there any solutions? Are there any solutions beyond some that are easily found by inspection? Are there finitely or infinitely many solutions? Can all solutions be found in theory? Can one in practice compute a full list of solutions?These traditional problems often lay unsolved for centuries, and mathematicians gradually came to understand their depth (in some cases), rather than treat them as puzzles.
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Factorial function Computation Factorial > Properties > Computation to fit into a machine word. The values 12! and 20!
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Information flow diagram Summary Information_flow_diagram An IFD usually uses "blobs" to decompose the system and sub-systems into elemental parts. Lines then indicate how the information travels from one system to another. IFDs are used in businesses, government agencies, television and cinematic processes.IFDs are often confused with data flow diagrams (DFDs).
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Horizontal gene transfer in evolution Resolution of uncertainty with phylogenomics Horizontal_gene_transfer_in_evolution > Resolution of uncertainty with phylogenomics This is not to say the tree of life is now resolved – we only have sampled a smattering of genomes, and many groups are not yet touched" These approaches are enabling estimates of the relative frequency of HGT; the relatively low values that have been observed suggests that the 'tree' is still a valid metaphor for evolution – but the tree is adorned with 'cobwebs' of horizontally transferred genes. This is the main conclusion of a 2005 study of more than 40 complete microbial genomic sequences by Fan Ge, Li-San Wang, and Junhyong Kim. They estimate the frequency of HGT events at about 2% of core genes per genome. Similar whole genome approaches to assessing evolution are also enabling progress in identifying very early events in the tree of life, such as a proposal that eukaryotes arose by fusion of two complete but very diverse prokaryote genomes: one from a bacterium and one from an archaeal cell.Such a fusion of organisms hypothesis for the origin of complex nucleated cells has been put forward by Lynn Margulis using quite different reasoning about symbiosis between a bacterium and an archaen arising in an ancient consortium of microbes.
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Complex Number Calculator Wartime activities and subsequent Bell Labs computers Complex_Number_Calculator > Wartime activities and subsequent Bell Labs computers Such intermittent errors would have been almost impossible to detect without some sort of internal redundancy. By contrast, vacuum tubes failed catastrophically, with a resulting computer failure obvious to its operators.
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Dry electrolyte Formation Ionic_solution > Formation Electrolyte solutions are normally formed when salt is placed into a solvent such as water and the individual components dissociate due to the thermodynamic interactions between solvent and solute molecules, in a process called "solvation". For example, when table salt (sodium chloride), NaCl, is placed in water, the salt (a solid) dissolves into its component ions, according to the dissociation reaction NaCl(s) → Na+(aq) + Cl−(aq)It is also possible for substances to react with water, producing ions. For example, carbon dioxide gas dissolves in water to produce a solution that contains hydronium, carbonate, and hydrogen carbonate ions.Molten salts can also be electrolytes as, for example, when sodium chloride is molten, the liquid conducts electricity. In particular, ionic liquids, which are molten salts with melting points below 100 °C, are a type of highly conductive non-aqueous electrolytes and thus have found more and more applications in fuel cells and batteries.An electrolyte in a solution may be described as "concentrated" if it has a high concentration of ions, or "dilute" if it has a low concentration.
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