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Earthquake environmental effects Summary Earthquake_environmental_effects Earthquake environmental effects are divided into two main types: Primary effects: which are the surface expression of the seismogenic source (e.g., surface faulting), normally observed for crustal earthquakes above a given magnitude threshold (typically Mw=5.5–6.0);Secondary effects: mostly this is the intensity of the ground shaking (e.g., landslides, liquefaction, etc.).The importance of a tool to measure earthquake Intensity was already outlined early in the 1990s. In 2007 the Environmental Seismic Intensity scale (ESI scale) was released, a new seismic intensity scale based only on the characteristics, size and areal distribution of earthquake environmental effects. A huge amount of data about associated with modern, historical and paleoearthquakes worldwide, a infrastructure developed in the framework of the INQUA TERPRO Commission on Paleoseismology and Active Tectonics.
Neural networks Neuroscience Neural_networks > Neuroscience Theoretical and computational neuroscience is the field concerned with the analysis and computational modeling of biological neural systems. Since neural systems are intimately related to cognitive processes and behaviour, the field is closely related to cognitive and behavioural modeling. The aim of the field is to create models of biological neural systems in order to understand how biological systems work. To gain this understanding, neuroscientists strive to make a link between observed biological processes (data), biologically plausible mechanisms for neural processing and learning (biological neural network models) and theory (statistical learning theory and information theory).
Spacecraft flight dynamics Attitude control Spacecraft_flight_dynamics > Attitude control Newton's second law, applied to rotational rather than linear motion, becomes: where τ x {\displaystyle {\boldsymbol {\tau }}_{x}} is the net torque about an axis of rotation exerted on the vehicle, Ix is its moment of inertia about that axis (a physical property that combines the mass and its distribution around the axis), and α x {\displaystyle \alpha _{x}} is the angular acceleration about that axis in radians per second per second. Therefore, the acceleration rate in degrees per second per second is Analogous to linear motion, the angular rotation rate ω x {\displaystyle {\boldsymbol {\omega }}_{x}} (degrees per second) is obtained by integrating α over time: and the angular rotation θ x {\displaystyle {\boldsymbol {\theta }}_{x}} is the time integral of the rate: The three principal moments of inertia Ix, Iy, and Iz about the roll, pitch and yaw axes, are determined through the vehicle's center of mass. The control torque for a launch vehicle is sometimes provided aerodynamically by movable fins, and usually by mounting the engines on gimbals to vector the thrust around the center of mass.
WKB approximation Approximation away from the turning points Liouville–Green_method > Application to the Schrödinger equation > Approximation away from the turning points The wavefunction can be rewritten as the exponential of another function Φ (closely related to the action), which could be complex, so that where Φ' indicates the derivative of Φ with respect to x. This derivative Φ' can be separated into real and imaginary parts by introducing the real functions A and B, The amplitude of the wavefunction is then while the phase is The real and imaginary parts of the Schrödinger equation then become Next, the semiclassical approximation is used. This means that each function is expanded as a power series in ħ. From the above equations, it can be seen that the power series must start with at least an order of 1/ħ to satisfy the real part of the equation: To the zeroth order in this expansion, the conditions on A and B can be written, The first derivatives A′(x) and B′(x) were discarded, because they include factors of order 1/ħ, higher than the dominant ħ−2. Then, if the amplitude varies sufficiently slowly as compared to the phase ( A 0 ( x ) = 0 {\displaystyle A_{0}(x)=0} ), it follows that which is only valid when the total energy is greater than the potential energy, as is always the case in classical motion. After the same procedure on the next order of the expansion, it follows that On the other hand, if it is the phase that varies slowly (as compared to the amplitude), ( B 0 ( x ) = 0 {\displaystyle B_{0}(x)=0} ) then which is only valid when the potential energy is greater than the total energy (the regime in which quantum tunneling occurs).
Lord Kelvin Thermodynamics Lord_Kelvin > Early life and work > Thermodynamics During his rewriting, he seems to have considered ideas that would subsequently give rise to the second law of thermodynamics. In Carnot's theory, lost heat was absolutely lost but Thomson contended that it was "lost to man irrecoverably; but not lost in the material world". Moreover, his theological beliefs led Thomson to extrapolate the second law to the cosmos, originating the idea of universal heat death.
General Relativity (book) Assessment General_Relativity_(book) > Assessment However, its quality is very variable. Topics such as geodetic motion in the Schwarzschild metric, the Krushkal extension, and energy extraction from black holes, are handled well while empirical tests of Einstein's theory are barely scratched and the treatment of advanced topics, including cosmology, is just too brief to be useful to students. Due to its heavy use of higher mathematics, it may not be suitable for an introductory course.Lee Smolin argued that General Relativity bridges the gap between the presentation of the material in older textbooks and the literature.
Kelvin–Stokes theorem Maxwell's equations Kelvin-Stokes_theorem > Applications > Maxwell's equations In the physics of electromagnetism, Stokes' theorem provides the justification for the equivalence of the differential form of the Maxwell–Faraday equation and the Maxwell–Ampère equation and the integral form of these equations. For Faraday's law, Stokes' theorem is applied to the electric field, E {\displaystyle \mathbf {E} }: For Ampère's law, Stokes' theorem is applied to the magnetic field, B {\displaystyle \mathbf {B} } :
Kathleen Collins (scientist) Research and career Kathleen_Collins_(scientist) > Research and career The telomere prevents the chromosomes from fusing. Most cells turn off telomerase, restricting their proliferation, whilst cancer cells activate telomerase and encourage cell division. In 2018 Collins reported the most detailed image of the three-dimensional molecular structure of telomerase, which offered hope for the design of drugs that can prevent cancer and ageing.Collins developed a scalpel-free approach to tumour biopsies.
Cross training In general sports Cross_training > In general sports Cross-training in sports and fitness involves combining exercises to work various parts of the body. Often one particular activity works certain muscle groups, but not others; cross-training aims to eliminate this imbalance.
Bloom (shader effect) Imperfect Focus Bloom_(shader_effect) > Theory > Imperfect Focus The Airy disc function falls off very quickly but has very wide tails (actually, infinitely wide tails). As long as the brightness of adjacent parts of the image are roughly in the same range, the effect of the blurring caused by the Airy disc is not particularly noticeable; but in parts of the image where very bright parts are adjacent to relatively darker parts, the tails of the Airy disc become visible and can extend far beyond the extent of the bright part of the image. In HDRR images, the effect can be reproduced by convolving the image with a windowed kernel of an Airy disc (for very good lenses), or by applying Gaussian blur (to simulate the effect of a less perfect lens), before converting the image to fixed-range pixels.
Schizosaccharomyces pombe Cytokinesis Fission_yeast > Cytokinesis The general features of cytokinesis are shown here. The site of cell division is determined before anaphase. The anaphase spindle (in green on the figure) is then positioned so that the segregated chromosomes are on opposite sides of the predetermined cleavage plane.
Classic RISC pipeline Control hazards Classic_RISC_pipeline > Hazards > Control hazards Delayed branches have been criticized as a poor short-term choice in ISA design: Compilers typically have some difficulty finding logically independent instructions to place after the branch (the instruction after the branch is called the delay slot), so that they must insert NOPs into the delay slots. Superscalar processors, which fetch multiple instructions per cycle and must have some form of branch prediction, do not benefit from delayed branches. The Alpha ISA left out delayed branches, as it was intended for superscalar processors.
Polarization identity Derivation Polarization_identities > Applications and consequences > Derivation The basic relation between the norm and the dot product is given by the equation Then and similarly Forms (1) and (2) of the polarization identity now follow by solving these equations for u ⋅ v , {\displaystyle {\textbf {u}}\cdot {\textbf {v}},} while form (3) follows from subtracting these two equations. (Adding these two equations together gives the parallelogram law.)
Chromosome instability Degenerating telomeres Chromosome_instability > How Chromosome instability is generated > Degenerating telomeres The key difference is the presence of a functional p53 damage response. When tumor cells have a mutation in p53 that results in a non-functional protein, telomeres can continue to shorten and proliferate, and the eroded segments are susceptible to chromosomal rearrangements through recombination and breakage-fusion-bridge cycles. Telomere loss can be lethal for many cells, but in the few that are able to restore the expression of telomerase can bring about a “stable” yet tumorigenic chromosome structure. Telomere degeneration thereby explains the transient period of extreme chromosomal instability observed in many emerging tumors.In experiments on mice where both telomerase and p53 were knocked out, they developed carcinomas with significant chromosomal instability similar to tumors seen in humans.
"grill" method Top sheet "grill"_method > Grill > Top sheet The rotor maps c into j and it maps k into m. If we ignore steckers for the moment, that means permutation Q would interchange (j m). For Q to be consistent, it must be the same for all six A B C D E F permutations. Look at the grill near permutation D to check if its Q also interchanges (j m).
Beer Brewing Beer > Brewing The process of filtering the spent grain from the wort and sparge water is called wort separation. The traditional process for wort separation is lautering, in which the grain bed itself serves as the filter medium. Some modern breweries prefer the use of filter frames, which allow for a more finely ground grist.Most modern breweries use a continuous sparge, collecting the original wort and the sparge water together.
High dynamic range rendering Light bloom High-dynamic-range_rendering > Limitations and compensations > Light bloom Light blooming is the result of scattering in the human lens, which human brain interprets as a bright spot in a scene. For example, a bright light in the background will appear to bleed over onto objects in the foreground. This can be used to create an illusion to make the bright spot appear to be brighter than it really is.
16 (number) Age 16 16_(number) > Age 16 It is a coming of age celebration that traditionally marks a girl's transition into womanhood. 16 is the minimum age that one can leave school in many states of the United States and Canada (however, restrictions apply and vary depending on state or province).
Relative entropy Relation to other quantities of information theory Principle_of_Minimum_Discrimination_Information > Relation to other quantities of information theory Many of the other quantities of information theory can be interpreted as applications of relative entropy to specific cases.
Kinematics Relative acceleration Relative_movement > Velocity and speed > Relative acceleration We also know that Δ r = ∫ v d t {\textstyle \Delta r=\int v\,{\text{d}}t} or Δ r {\displaystyle \Delta r} is the area under a velocity–time graph. We can take Δ r {\displaystyle \Delta r} by adding the top area and the bottom area. The bottom area is a rectangle, and the area of a rectangle is the A ⋅ B {\displaystyle A\cdot B} where A {\displaystyle A} is the width and B {\displaystyle B} is the height.
Shear strength (soil) Undrained strength Shear_strength_(soil) > Undrained strength An example of this is rapid loading of sands during an earthquake, or the failure of a clay slope during heavy rain, and applies to most failures that occur during construction. As an implication of undrained condition, no elastic volumetric strains occur, and thus Poisson's ratio is assumed to remain 0.5 throughout shearing. The Tresca soil model also assumes no plastic volumetric strains occur.
Friction loss Calculating volumetric flow Friction_loss > Calculating volumetric flow S = h f L = 1 ρ g Δ p L . {\displaystyle S={\frac {h_{f}}{L}}={\frac {1}{\rho \mathrm {g} }}{\frac {\Delta p}{L}}.} where ρ = density of the fluid, (SI kg / m3) g = the local acceleration due to gravity;
Instrumentation in petrochemical industries Other instrumentation Instrumentation_in_petrochemical_industries > Other instrumentation Packaged items of equipment (compressors, diesel engines, electricity generators, etc) are fitted with local vendor supplied instrumentation. When equipment malfunctions a multivariable signal (UA) is sent to the control room. The fire and gas detection system comprises local sensors to detect the presence of gas, smoke or fire.
Breathing gases Oxygen therapy Breathing_air > Medical breathing gases > Oxygen therapy Oxygen can be given in a number of ways including nasal cannula, face mask, and inside a hyperbaric chamber.High concentrations of oxygen can cause oxygen toxicity such as lung damage or result in respiratory failure in those who are predisposed. It can also dry out the nose and increase the risk of fires in those who smoke. The target oxygen saturation recommended depends on the condition being treated.
Anaerobic glycolysis Summary Anaerobic_glycolysis Anaerobic glycolysis is the transformation of glucose to lactate when limited amounts of oxygen (O2) are available. Anaerobic glycolysis is only an effective means of energy production during short, intense exercise, providing energy for a period ranging from 10 seconds to 2 minutes. This is much faster than aerobic metabolism. The anaerobic glycolysis (lactic acid) system is dominant from about 10–30 seconds during a maximal effort.
Causal AI Summary Causal_AI Professor Bareinboim’s research focuses on causal and counterfactual inference and their applications to data-driven fields in the health and social sciences as well as artificial intelligence and machine learning. Technological research and consulting firm Gartner for the first time included causal AI in its 2022 Hype Cycle report, citing it as one of five critical technologies in accelerated AI automation. == References ==
Laser Cooling Doppler cooling Laser_cooled > Methods > Doppler cooling Doppler cooling, which is usually accompanied by a magnetic trapping force to give a magneto-optical trap, is by far the most common method of laser cooling. It is used to cool low density gases down to the Doppler cooling limit, which for rubidium-85 is around 150 microkelvins. In Doppler cooling, initially, the frequency of light is tuned slightly below an electronic transition in the atom. Because the light is detuned to the "red" (i.e., at lower frequency) of the transition, the atoms will absorb more photons if they move towards the light source, due to the Doppler effect.
Oval BA Chemical composition Oval_BA > Chemical composition The reason for this low abundance is not entirely understood, but some of the helium may have condensed into the core of Jupiter. This condensation is likely to be in the form of helium rain: as hydrogen turns into the metallic state at depths of more than 10,000 km, helium separates from it forming droplets which, being denser than the metallic hydrogen, descend towards the core. This can also explain the severe depletion of neon (see Table), an element that easily dissolves in helium droplets and would be transported in them towards the core as well.The atmosphere contains various simple compounds such as water, methane (CH4), hydrogen sulfide (H2S), ammonia (NH3) and phosphine (PH3).
Group dynamics Types of groups Group_dynamics > Intragroup dynamics > Types of groups For example, in an experiment, participants were asked to sort a number of groups into categories based on their own criteria. Examples of groups to be sorted were a sports team, a family, people at a bus stop and women. It was found that participants consistently sorted groups into four categories: intimacy groups, task groups, loose associations, and social categories. These categories are conceptually similar to the four basic types to be discussed. Therefore, it seems that individuals intuitively define aggregations of individuals in this way.
Java Native Interface Performance Java_Native_Interface > Performance If the method is passed an object, or needs to make a callback, then the native method will likely be making its own calls to the JVM. Accessing Java fields, methods and types from the native code requires something similar to reflection. Signatures are specified in strings and queried from the JVM.
Wifi Protected Setup Modes Wifi_Protected_Setup > Modes The standard emphasizes usability and security, and allows four modes in a home network for adding a new device to the network: PIN method In which a PIN has to be read from either a sticker or display on the new wireless device. This PIN must then be entered at the "representant" of the network, usually the network's access point. Alternately, a PIN provided by the access point may be entered into the new device. This method is the mandatory baseline mode and everything must support it.
Spontaneously hypertensive rat Blood pressure in SHR depends on the kidney Spontaneously_hypertensive_rat > Blood pressure in SHR depends on the kidney Hypertensive development is somehow connected to the kidney. Transplanting a kidney from SHR to a normotensive Wistar rat increases blood pressure in the recipient. Conversely, transferring a Wistar kidney to SHR normalizes blood pressure in the recipient. This also happens if transplantation takes place at young age before established hypertension in the donors, indicating a primary role for the kidney in the development of hypertension in SHR.
Tropospheric ozone Summary Ground-level_ozone With more heat and sunlight in the summer months, more ozone is formed which is why regions often experience higher levels of pollution in the summer months. Although the same molecule, ground-level ozone can be harmful to human health, unlike stratospheric ozone that protects the earth from excess UV radiation.Photolysis of ozone occurs at wavelengths below approximately 310–320 nanometres. This reaction initiates a chain of chemical reactions that remove carbon monoxide, methane, and other hydrocarbons from the atmosphere via oxidation. Therefore, the concentration of tropospheric ozone affects how long these compounds remain in the air. If the oxidation of carbon monoxide or methane occur in the presence of nitrogen monoxide (NO), this chain of reactions has a net product of ozone added to the system.
Data quality Overview Data_quality > Overview It might be able to manage "householding", or finding links between spouses at the same address, for example. Finally, it often can build a "best of breed" record, taking the best components from multiple data sources and building a single super-record. Monitoring - keeping track of data quality over time and reporting variations in the quality of data.
Unsaturated fatty acid Essential fatty acids Saturated_fatty_acid > Circulation > Metabolism > Essential fatty acids Fatty acids that are required for good health but cannot be made in sufficient quantity from other substrates, and therefore must be obtained from food, are called essential fatty acids. There are two series of essential fatty acids: one has a double bond three carbon atoms away from the methyl end; the other has a double bond six carbon atoms away from the methyl end. Humans lack the ability to introduce double bonds in fatty acids beyond carbons 9 and 10, as counted from the carboxylic acid side. Two essential fatty acids are linoleic acid (LA) and alpha-linolenic acid (ALA).
Ozone generator Low level ozone in urban areas Oxygen_3 > Ozone in Earth's atmosphere > Low level ozone > Low level ozone in urban areas Of course there are also other reasons that ozone levels remain high. These include: a growing population meaning more car emissions, and the mountains along the NCFR that can trap emissions. If interested, daily air quality readings can be found at the Colorado Department of Public Health and Environment's website. As noted earlier, Denver continues to experience high levels of ozone to this day. It will take many years and a systems-thinking approach to combat this issue of high ozone levels in the Front Range of Colorado.
Hill reaction Biochemistry Hill_reaction > Biochemistry Photosynthesis is the process in which light energy is absorbed and converted to chemical energy. This chemical energy is eventually used in the conversion of carbon dioxide to sugar in plants.
Mutually recursive Summary Mutually_recursive In mathematics and computer science, mutual recursion is a form of recursion where two mathematical or computational objects, such as functions or datatypes, are defined in terms of each other. Mutual recursion is very common in functional programming and in some problem domains, such as recursive descent parsers, where the datatypes are naturally mutually recursive.
Adversarial machine learning HopSkipJump Attack Adversarial_machine_learning > Specific attack types > Adversarial examples > Black box attacks > HopSkipJump Attack This black box attack was also proposed as a query efficient attack, but one that relies solely on access to any input's predicted output class. In other words, the HopSkipJump attack does not require the ability to calculate gradients or access to score values like the Square Attack, and will require just the model's class prediction output (for any given input). The proposed attack is split into two different settings, targeted and untargeted, but both are built from the general idea of adding minimal perturbations that leads to a different model output. In the targeted setting, the goal is to cause the model to misclassify the perturbed image to a specific target label (that is not the original label).
Virtual leak S Glossary_of_engineering:_M–Z > S Stefan–Boltzmann lawThe Stefan–Boltzmann law describes the power radiated from a black body in terms of its temperature. Specifically, the Stefan–Boltzmann law states that the total energy radiated per unit surface area of a black body across all wavelengths per unit time j ⋆ {\displaystyle j^{\star }} (also known as the black-body radiant emittance) is directly proportional to the fourth power of the black body's thermodynamic temperature T: j ⋆ = σ T 4 . {\displaystyle j^{\star }=\sigma T^{4}.}
Droop speed control Summary Droop_speed_control Droop speed control is a control mode used for AC electrical power generators, whereby the power output of a generator reduces as the line frequency increases. It is commonly used as the speed control mode of the governor of a prime mover driving a synchronous generator connected to an electrical grid. It works by controlling the rate of power produced by the prime mover according to the grid frequency. With droop speed control, when the grid is operating at maximum operating frequency, the prime mover's power is reduced to zero, and when the grid is at minimum operating frequency, the power is set to 100%, and intermediate values at other operating frequencies.
Higher-order function Direct support Higher_order_function > Support in programming languages > Direct support The examples are not intended to compare and contrast programming languages, but to serve as examples of higher-order function syntax In the following examples, the higher-order function twice takes a function, and applies the function to some value twice. If twice has to be applied several times for the same f it preferably should return a function rather than a value. This is in line with the "don't repeat yourself" principle.
Spline curve Examples Spline_curve > Examples It is also called a step function. The next most simple spline has degree 1. It is also called a linear spline.
Magical formula Formulae Magical_formula > Formulae HRILIU. used in Liber XV, The Gnostic Mass.
History of calculus Greece History_of_calculus > Early precursors of calculus > Ancient > Greece Archimedes developed this method further, while also inventing heuristic methods which resemble modern day concepts somewhat in his The Quadrature of the Parabola, The Method, and On the Sphere and Cylinder. It should not be thought that infinitesimals were put on a rigorous footing during this time, however. Only when it was supplemented by a proper geometric proof would Greek mathematicians accept a proposition as true.
Linear vector space Related concepts Real_vector_space > Related concepts Coordinate vector, the n-tuple of the coordinates of a vector on a basis of n elements. For a vector space over a field F, these n-tuples form the vector space F n {\displaystyle F^{n}} (where the operation are pointwise addition and scalar multiplication). Displacement vector, a vector that specifies the change in position of a point relative to a previous position.
Hemorrhagic transformation Signs and symptoms Hemorrhagic_transformation > Signs and symptoms Signs and symptoms can vary depending on the severity and location of the bleeding within the brain tissue. In the medical literature, various criteria have been used to establish whether a hemorrhagic infarction is symptomatic or not. Studies have shown that only parenchymal hematomas are strongly associated with long-term deterioration and worsening of the patient's condition. Most cases of hemorrhagic transformation, including the majority of petechial hemorrhages, are asymptomatic and do not cause noticeable symptoms.Some common symptoms might include: Headache Changes in consciousness Weakness or numbness Seizures Speech difficulties Vision problems
Frozen section procedure Summary Frozen_section_procedure When operating on a previously confirmed malignancy, the main purpose of the pathologist is to inform the surgeon if the resection margin is clear of residual cancer, or if residual cancer is present at the resection margin. The method of processing is usually done with the bread loafing technique. But margin controlled surgery (CCPDMA) can be performed using a variety of tissue cutting and mounting methods, including Mohs surgery.
Decarboxylation reaction Hydrodecarboxylation Decarboxylation_reaction > In organic chemistry > Hydrodecarboxylation The reaction involves the conjugate base of the carboxyl group, a carboxylate ion, and an unsaturated receptor of electron density, such as a protonated carbonyl group. Where reactions entail heating the carboxylic acid with concentrated hydrochloric acid, such a direct route is impossible as it would produce protonated carbon dioxide. In these cases, the reaction is likely to occur by initial addition of water and a proton.
Primer extension Summary Primer_extension Unlike S1 mapping, however, primer extension can only be used to locate the 5’-end of an mRNA transcript because the DNA synthesis required for the assay relies on reverse transcriptase (only polymerizes in the 5’ → 3’ direction). Primer extension is unaffected by splice sites and is thus preferable in situations where intervening splice sites prevent S1 mapping. Finally, primer extension is more accurate than S1 mapping because the S1 nuclease used in S1 mapping can “nibble off” ends of the RNA-DNA hybrid or fail to degrade the single-stranded regions completely, making a transcript either appear shorter or longer.
℞ Drug equivalence and non-substitution ℞ > Contents > Drug equivalence and non-substitution Many brand name drugs have cheaper generic drug substitutes that are therapeutically and biochemically equivalent. Prescriptions will also contain instructions on whether the prescriber will allow the pharmacist to substitute a generic version of the drug. This instruction is communicated in a number of ways. In some jurisdictions, the preprinted prescription contains two signature lines: one line has "dispense as written" printed underneath; the other line has "substitution permitted" underneath.
Social construction of technology Symmetry Social_construction_of_technology > Legacy of the Strong Programme in the sociology of science > Symmetry A weak reading of the Principle of Symmetry points out that there often are many competing theories or technologies, which all have the potential to provide slightly different solutions to similar problems. In these cases, sociological factors tip the balance between them: that's why we should pay equal attention to them. A strong, social constructivist reading would add that even the emergence of the questions or problems to be solved are governed by social determinations, so the Principle of Symmetry is applicable even to the apparently purely technical issues.
Cystic kidney disease Summary Cystic_kidney_disease Renal cysts have been reported in more than 50% of patients over the age of 50. Typically, cysts grow up to 2.88 mm annually and may cause related pain and/or hemorrhage.Of the cystic kidney diseases, the most common is polycystic kidney disease with two sub-types: the less prevalent autosomal recessive and more prevalent autosomal dominant. Autosomal recessive polycystic kidney disease (ARPKD) is primarily diagnosed in infants and young children while autosomal dominant polycystic kidney disease (ADPKD) is most often diagnosed in adulthood.Another example of cystic kidney disease is Medullary sponge kidney.
Tachyonic antitelephone Paradoxes Tachyonic_antitelephone > Paradoxes Then the exchange of messages will take place if and only if it does not take place. This is a genuine paradox, a causal contradiction. They concluded that superluminal particles such as tachyons are therefore not allowed to convey signals.
Ohm metre Ideal case Electrically_conductive > Definition > Ideal case In a hydraulic analogy, passing current through a high-resistivity material is like pushing water through a pipe full of sand - while passing current through a low-resistivity material is like pushing water through an empty pipe. If the pipes are the same size and shape, the pipe full of sand has higher resistance to flow. Resistance, however, is not solely determined by the presence or absence of sand.
Crowds (anonymity network) Definitions Crowds_(anonymity_network) > Definitions Crowds uses and defines the following terms: Sender The initiator of a message Receiver The final recipient of a message Probable Innocence The attacker is unable to have greater than 50% confidence that any node initiated the message (a node appears equally likely to have initiated the message as to not have - each user is more likely innocent than not.) Local Eavesdropper An attacker that can observe all incoming and outgoing messages for any proper subset of the nodes Corrupt Node A node is corrupt if it uses information obtained from forwarding the message to determine the sender C {\displaystyle C} The number of corrupt nodes N {\displaystyle N} The number of nodes ( N − C {\displaystyle N-C} is the number of good nodes) p f {\displaystyle p_{f}} The probability of forwarding
Spectral theory Summary Spectral_theory In mathematics, spectral theory is an inclusive term for theories extending the eigenvector and eigenvalue theory of a single square matrix to a much broader theory of the structure of operators in a variety of mathematical spaces. It is a result of studies of linear algebra and the solutions of systems of linear equations and their generalizations. The theory is connected to that of analytic functions because the spectral properties of an operator are related to analytic functions of the spectral parameter.
Body image law Summary Body_image_law Body image law is the developing area of law that, according to Dr Marilyn Bromberg of the University of Western Australia Law School and Cindy Halliwell, a law student at Deakin University, "encompasses the bills, laws and government actions (such as establishing parliamentary inquiries and creating policies) that may help to improve the body image of the general public, and particularly of young people". Among the reasons for implementing law in this area is to prevent the images of unhealthily thin women causing poor body image which can, along with other factors, lead to an eating disorder.
Finite resource Nuclear fuels Non-renewable_fuel > Nuclear fuels In 1987, the World Commission on Environment and Development (WCED) classified fission reactors that produce more fissile nuclear fuel than they consume (i.e. breeder reactors) among conventional renewable energy sources, such as solar and falling water. The American Petroleum Institute likewise does not consider conventional nuclear fission as renewable, but rather that breeder reactor nuclear power fuel is considered renewable and sustainable, noting that radioactive waste from used spent fuel rods remains radioactive and so has to be very carefully stored for several hundred years. With the careful monitoring of radioactive waste products also being required upon the use of other renewable energy sources, such as geothermal energy.The use of nuclear technology relying on fission requires Naturally occurring radioactive material as fuel. Uranium, the most common fission fuel, is present in the ground at relatively low concentrations and mined in 19 countries.
Parallel programming model Terminology Parallel_programming_model > Terminology Parallel programming models are closely related to models of computation. A model of parallel computation is an abstraction used to analyze the cost of computational processes, but it does not necessarily need to be practical, in that it can be implemented efficiently in hardware and/or software. A programming model, in contrast, does specifically imply the practical considerations of hardware and software implementation.A parallel programming language may be based on one or a combination of programming models. For example, High Performance Fortran is based on shared-memory interactions and data-parallel problem decomposition, and Go provides mechanism for shared-memory and message-passing interaction.
Boxer shorts Design Boxer_shorts > Design There are two types of yoke boxers: one in which there is a short piece of elastic on each side of the waistband which snugs up the yoke to fit the waist; and "tie-sides" which have narrow cloth tapes on each side of the waist yoke, like strings, which are tightened and knotted by the wearer to make an exact fit. This style of underpant was very common during World War II, when the rubber needed for elastic waistbands had to be used for military purposes.
Power beaming Field regions Wireless_energy_transfer > Field regions Electric and magnetic fields are created by charged particles in matter such as electrons. A stationary charge creates an electrostatic field in the space around it. A steady current of charges (direct current, DC) creates a static magnetic field around it. The above fields contain energy, but cannot carry power because they are static.
Glycemic control Summary Glycemic_control Other forms of diabetes mellitus, such as the various forms of maturity-onset diabetes of the young, may represent some combination of insufficient insulin production and insulin resistance. Some degree of insulin resistance may also be present in a person with type 1 diabetes. The main goal of diabetes management and control is, as far as possible, to restore carbohydrate metabolism to a normal state.
Accessibility of telehealth services Summary Accessibility_of_telehealth_services Accessibility of telehealth services or F.780.2 is a technical standard developed by the World Health Organization and ITU (Study Group 16) that defines accessibility requirements for technical features to be used and implemented by governments, healthcare providers and manufacturers of telehealth platforms to facilitate the access and use of telehealth services by persons with disabilities.
Vascular rings Diagnosis Aortic_ring > Diagnosis Infants with vascular rings typically present before 12 months with respiratory or esophageal symptoms like stridor, wheezing, cough, dysphagia, or difficulty feeding. The stridor improves with neck extension, differentiating from laryngomalacia which is relieved by prone or upright positioning, and will not be relieved with corticosteroids or epinephrine, unlike croup. Diagnosis requires a high degree of clinical suspicion and can be confirmed with barium contrast esophagogram for those with esophageal symptoms, bronchoscopy, or CT or MRI.
Artificial Neural Networks History Parameter_(machine_learning) > History This provided more processing power for the development of practical artificial neural networks in the 1980s.Neural networks' early successes included predicting the stock market and in 1995 a (mostly) self-driving car.Geoffrey Hinton et al. (2006) proposed learning a high-level representation using successive layers of binary or real-valued latent variables with a restricted Boltzmann machine to model each layer. In 2012, Ng and Dean created a network that learned to recognize higher-level concepts, such as cats, only from watching unlabeled images. Unsupervised pre-training and increased computing power from GPUs and distributed computing allowed the use of larger networks, particularly in image and visual recognition problems, which became known as "deep learning".Ciresan and colleagues (2010) showed that despite the vanishing gradient problem, GPUs make backpropagation feasible for many-layered feedforward neural networks. Between 2009 and 2012, ANNs began winning prizes in image recognition contests, approaching human level performance on various tasks, initially in pattern recognition and handwriting recognition. For example, the bi-directional and multi-dimensional long short-term memory (LSTM) of Graves et al. won three competitions in connected handwriting recognition in 2009 without any prior knowledge about the three languages to be learned.Ciresan and colleagues built the first pattern recognizers to achieve human-competitive/superhuman performance on benchmarks such as traffic sign recognition (IJCNN 2012).
Statistical proof Test and proof Statistical_proof > Test and proof Researchers sample from populations, which provide estimates of the parameters, to calculate the mean or standard deviation. If the entire population is sampled, then the sample statistic mean and distribution will converge with the parametric distribution.Using the scientific method of falsification, the probability value that the sample statistic is sufficiently different from the null-model than can be explained by chance alone is given prior to the test. Most statisticians set the prior probability value at 0.05 or 0.1, which means if the sample statistics diverge from the parametric model more than 5 (or 10) times out of 100, then the discrepancy is unlikely to be explained by chance alone and the null-hypothesis is rejected.
Environmental stresses Biology of stress General_adaptation_syndrome > Biology of stress The ANS receives inputs from the medulla, hypothalamus, limbic system, prefrontal cortex, midbrain and monoamine nuclei.The activity of the sympathetic nervous system drives what is called the "fight or flight" response. The fight or flight response to emergency or stress involves mydriasis, increased heart rate and force contraction, vasoconstriction, bronchodilation, glycogenolysis, gluconeogenesis, lipolysis, sweating, decreased motility of the digestive system, secretion of the epinephrine and cortisol from the adrenal medulla, and relaxation of the bladder wall. The parasympathetic nervous response, "rest and digest", involves return to maintaining homeostasis, and involves miosis, bronchoconstriction, increased activity of the digestive system, and contraction of the bladder walls.
Comma category Summary Comma_category In mathematics, a comma category (a special case being a slice category) is a construction in category theory. It provides another way of looking at morphisms: instead of simply relating objects of a category to one another, morphisms become objects in their own right. This notion was introduced in 1963 by F. W. Lawvere (Lawvere, 1963 p. 36), although the technique did not become generally known until many years later.
Vitamin E Cardiovascular diseases Vitamin_E > Research > Cardiovascular diseases The problem with observational studies is that these cannot confirm a relation between the lower risk of coronary heart disease and vitamin E consumption because of confounding factors. Diet higher in vitamin E may also be higher in other, unidentified components that promote heart health, or people choosing such diets may be making other healthy lifestyle choices.There is some supporting evidence from randomized clinical trials (RCTs). A meta-analysis on the effects of alpha-tocopherol supplementation in RCTs on aspects of cardiovascular health reported that when consumed without any other antioxidant nutrient, the relative risk of heart attack was reduced by 18%.
Loop-based music software Modern looping Music_loop > Modern looping Today, many musicians use digital hardware and software devices to create and modify loops, often in conjunction with various electronic musical effects. A loop can be created by a looper pedal, a device that records the signal from a guitar or other audio source and then plays the recorded passage over and over again. In the early 1990s, dedicated digital devices were invented specifically for use in live looping, i.e. loops that are recorded in front of a live audience.Many hardware loopers exist, some in rack unit form, but primarily as effect pedals. The discontinued Lexicon JamMan, Gibson Echoplex Digital Pro, Electrix Repeater, and Looperlative LP1 are 19" rack units.
Arithmetic circuit Algebraic P and NP Arithmetic_circuit > Algebraic P and NP One of the basic notions in complexity theory is the notion of completeness. Given a class of polynomials (such as VP or VNP), a complete polynomial f {\displaystyle f} for this class is a polynomial with two properties: (1) it is part of the class, and (2) any other polynomial g {\displaystyle g} in the class is easier than f , {\displaystyle f,} in the sense that if f {\displaystyle f} has a small circuit then so does g . {\displaystyle g.}
Mini PCIE Transaction layer PCI_express_card > Hardware protocol summary > Transaction layer The advantage of this scheme (compared to other methods such as wait states or handshake-based transfer protocols) is that the latency of credit return does not affect performance, provided that the credit limit is not encountered. This assumption is generally met if each device is designed with adequate buffer sizes. PCIe 1.x is often quoted to support a data rate of 250 MB/s in each direction, per lane.
Composition of Mars Sedimentary rocks Composition_of_Mars > Mineralogy and petrology > Sedimentary rocks Layered sedimentary deposits are widespread on Mars. These deposits probably consist of both sedimentary rock and poorly indurated or unconsolidated sediments. Thick sedimentary deposits occur in the interior of several canyons in Valles Marineris, within large craters in Arabia and Meridiani Planum (see Henry Crater for example), and probably comprise much of the deposits in the northern lowlands (e.g., Vastitas Borealis Formation). The Mars Exploration Rover Opportunity landed in an area containing cross-bedded (mainly eolian) sandstones (Burns formation).
DNA oxidation Potential factors for RNA quality control DNA_oxidation > Potential factors for RNA quality control This theory is upheld by the fact that level of oxidized RNA decreases after removal of the oxidative challenge. Some potential factors include ribonucleases, which are suspected to selectively degrade damaged RNAs under stresses. Also enzymes working at RNA precursor pool level, are known to control quality of RNA sequence by changing error precursor to the form that can't be included directly into nascent strand. == References ==
Ungula Cylindrical ungula Ungula > Cylindrical ungula A cylindrical ungula of base radius r and height h has volume V = 2 3 r 2 h {\displaystyle V={2 \over 3}r^{2}h} ,.Its total surface area is A = 1 2 π r 2 + 1 2 π r r 2 + h 2 + 2 r h {\displaystyle A={1 \over 2}\pi r^{2}+{1 \over 2}\pi r{\sqrt {r^{2}+h^{2}}}+2rh} ,the surface area of its curved sidewall is A s = 2 r h {\displaystyle A_{s}=2rh} ,and the surface area of its top (slanted roof) is A t = 1 2 π r r 2 + h 2 {\displaystyle A_{t}={1 \over 2}\pi r{\sqrt {r^{2}+h^{2}}}} .
Digestate Summary Anaerobic_digestate Digestate is the material remaining after the anaerobic digestion (decomposition under low oxygen conditions) of a biodegradable feedstock. Anaerobic digestion produces two main products: digestate and biogas. Digestate is produced both by acidogenesis and methanogenesis and each has different characteristics. These characteristics stem from the original feedstock source as well as the processes themselves.
Continuously differentiable Differentiability and continuity Differentiable_map > Differentiability and continuity Most functions that occur in practice have derivatives at all points or at almost every point. However, a result of Stefan Banach states that the set of functions that have a derivative at some point is a meagre set in the space of all continuous functions. Informally, this means that differentiable functions are very atypical among continuous functions. The first known example of a function that is continuous everywhere but differentiable nowhere is the Weierstrass function.
Bondi k-calculus Bondi's k-factor Bondi_k-calculus > Bondi's k-factor : 40 If Alice and Bob were to swap roles, and Bob sent flashes of light to Alice, the Principle of Relativity (Einstein's first postulate) implies that the k-factor from Bob to Alice would be the same value as the k-factor from Alice to Bob, as all inertial observers are equivalent. So the k-factor depends only on the relative speed between the observers and nothing else. : 80
Tucker's lemma Run-time Tucker's_lemma > Run-time The run-time of the algorithm described above is polynomial in the triangulation size. This is considered bad, since the triangulations might be very large. It would be desirable to find an algorithm which is logarithmic in the triangulation size. However, the problem of finding a complementary edge is PPA-complete even for n = 2 {\displaystyle n=2} dimensions. This implies that there is not too much hope for finding a fast algorithm.
Antiarrhythmic agent Class IV agents Antiarrhythmic_agent > Vaughan Williams classification > Class IV agents Class IV agents are slow non-dihydropyridine calcium channel blockers. They decrease conduction through the AV node, and shorten phase two (the plateau) of the cardiac action potential. They thus reduce the contractility of the heart, so may be inappropriate in heart failure. However, in contrast to beta blockers, they allow the body to retain adrenergic control of heart rate and contractility.Class IV agents include verapamil and diltiazem.
Continuous Fourier transform Distributions, one-dimensional Fourier_transformations > Tables of important Fourier transforms > Functional relationships, one-dimensional The Fourier transforms in this table may be found in Erdélyi (1954) or Kammler (2000, appendix).
Glossary of electrical and electronics engineering R Glossary_of_electrical_and_electronics_engineering > R recursive least squares filterAn algorithm for a digital filter system. Reed switchAn electrical switch made of two thin strips of ferromagnetic metal, which touch when subject to a magnetic field. regenerative brakingA braking scheme that returns energy to the source.
Causal Markov condition Summary Causal_Markov_condition This also means that a node is conditionally independent of the entire network, given its Markov blanket. The related Causal Markov (CM) condition states that, conditional on the set of all its direct causes, a node is independent of all variables which are not effects or direct causes of that node. In the event that the structure of a Bayesian network accurately depicts causality, the two conditions are equivalent. However, a network may accurately embody the Markov condition without depicting causality, in which case it should not be assumed to embody the causal Markov condition.
Riparian buffer Habitat benefits Riparian_buffer > Benefits > Habitat benefits The large trees in the first zone of the riparian buffer provide shade and therefore cooling for the water, increasing productivity and increasing habitat quality for aquatic species. When branches and stumps (large woody debris) fall into the stream from the riparian zone, more stream habitat features are created. Carbon is added as an energy source for biota in the stream.
Accuracy paradox Summary Accuracy_paradox Precision and recall are better measures in such cases. The underlying issue is that there is a class imbalance between the positive class and the negative class. Prior probabilities for these classes need to be accounted for in error analysis. Precision and recall help, but precision too can be biased by very unbalanced class priors in the test sets.
Philopatry Speciation Philopatry > Natal philopatry > Consequences of philopatry > Speciation Genetic homogeneity can be attributed to one of two explanations, both of which indicate that natal philopatry is not absolute within a species. Firstly, a lack of divergence may be due to founder effects, which explains how individuals that start new populations carry the genes of their source population. If only a short (in evolutionary timescales) period of time has passed, insufficient divergence may have occurred.
Stable Diffusion ControlNet Stable_Diffusion > Capabilities > ControlNet The "zero convolution" is a 1×1 convolution with both weight and bias initialized to zero. Before training, all zero convolutions produce zero output, preventing any distortion caused by ControlNet. No layer is trained from scratch; the process is still fine-tuning, keeping the original model secure. This method enables training on small-scale or even personal devices.
Short interfering RNA Post-transcriptional gene silencing Short_interfering_RNA > Post-transcriptional gene silencing The siRNA-induced post transcriptional gene silencing is initiated by the assembly of the RNA-induced silencing complex (RISC). The complex silences certain gene expression by cleaving the mRNA molecules coding the target genes. To begin the process, one of the two siRNA strands, the guide strand (anti-sense strand), will be loaded into the RISC while the other strand, the passenger strand (sense strand), is degraded. Certain Dicer enzymes may be responsible for loading the guide strand into RISC.
Generative pre-trained transformer Initial developments Generative_pre-trained_transformer > History > Initial developments Generative pretraining (GP) was a long-established concept in machine learning applications, but the transformer architecture was not available until 2017 when it was invented by employees at Google. That development led to the emergence of large language models such as BERT in 2018 which was a pre-trained transformer (PT) but not designed to be generative (BERT was an "encoder-only" model). Also around that time, in 2018, OpenAI published its article entitled "Improving Language Understanding by Generative Pre-Training," in which it introduced the first generative pre-trained transformer (GPT) system ("GPT-1").Prior to transformer-based architectures, the best-performing neural NLP (natural language processing) models commonly employed supervised learning from large amounts of manually-labeled data. The reliance on supervised learning limited their use on datasets that were not well-annotated, and also made it prohibitively expensive and time-consuming to train extremely large language models.The semi-supervised approach OpenAI employed to make a large-scale generative system—and was first to do with a transformer model—involved two stages: an unsupervised generative "pretraining" stage to set initial parameters using a language modeling objective, and a supervised discriminative "fine-tuning" stage to adapt these parameters to a target task.
Raven paradox Orthodox approach Raven_paradox > Proposed resolutions > Rejections of Hempel's equivalence condition > Orthodox approach This contrasts with the Bayesian approach, which requires that the hypothesis be assigned a prior probability, which is revised in the light of the observed data to obtain the final probability of the hypothesis. Within the Bayesian framework there is no risk of error since hypotheses are not accepted or rejected; instead they are assigned probabilities.
Membrane structure Literature Membrane_structure > Literature ETFE, Technology and Design, Annette LeCuyer, Verlag Birkhäuser, ISBN 978-3-7643-8563-7 Membrane Structures, Hrsg. Klaus-Michael Koch, Verlag Prestel, ISBN 978-3-7913-3049-5
Hex editor Summary Hexadecimal_editor A hex editor (or binary file editor or byte editor) is a computer program that allows for manipulation of the fundamental binary data that constitutes a computer file. The name 'hex' comes from 'hexadecimal', a standard numerical format for representing binary data. A typical computer file occupies multiple areas on the storage medium, whose contents are combined to form the file. Hex editors that are designed to parse and edit sector data from the physical segments of floppy or hard disks are sometimes called sector editors or disk editors.
Cellular aging Summary Cellular_death PCD serves fundamental functions during both plant and animal tissue development. Apoptosis and autophagy are both forms of programmed cell death. Necrosis is the death of a cell caused by external factors such as trauma or infection and occurs in several different forms.
Fisher's geometric model Conceptualization Fisher's_geometric_model > Conceptualization The more independent dimensions of variation the phenotype has, the more difficult is improvement resulting from random changes. If there are many different ways to change a phenotype it becomes very unlikely that a random change affects the right combination of traits in the right way to improve fitness. Fisher noted that the smaller the effect, the higher the chance that a change is beneficial.
Heat load Summary Thermal_stress In mechanics and thermodynamics, thermal stress is mechanical stress created by any change in temperature of a material. These stresses can lead to fracturing or plastic deformation depending on the other variables of heating, which include material types and constraints. Temperature gradients, thermal expansion or contraction and thermal shocks are things that can lead to thermal stress.
Aquatic sciences Limnology Aquatic_sciences > Limnology In order to increase their understanding of what they are studying, limnologists employ three main study techniques. The first study technique has to do with observations. Limnologists make descriptive observations of conditions and note how those conditions have changed over time.
Egocentric vision Applications Egocentric_vision > Applications A collection of studies published in a special theme issue of the American Journal of Preventive Medicine has demonstrated the potential of lifelogs captured through wearable cameras from a number of viewpoints. In particular, it has been shown that used as a tool for understanding and tracking lifestyle behaviour, lifelogs would enable the prevention of noncommunicable diseases associated to unhealthy trends and risky profiles (such as obesity, depression, etc.). In addition, used as a tool of re-memory cognitive training, lifelogs would enable the prevention of cognitive and functional decline in elderly people. More recently, egocentric cameras have been used to study human and animal cognition, human-human social interaction, human-robot interaction, human expertise in complex tasks. Other applications include navigation/assistive technologies for the blind, monitoring and assistance of industrial workflows, and augmented reality interfaces.
Carbonate rocks Summary Carbonate_rock Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO3), and dolomite rock (also known as dolostone), which is composed of mineral dolomite (CaMg(CO3)2). They are usually classified based on texture and grain size.
Aircraft stability Spiral mode trajectory Aircraft_flight_dynamics > Stability > Dynamic stability and control > Lateral modes > Spiral mode > Spiral mode trajectory In studying the trajectory, it is the direction of the velocity vector, rather than that of the body, which is of interest. The direction of the velocity vector when projected on to the horizontal will be called the track, denoted μ {\displaystyle \mu } (mu). The body orientation is called the heading, denoted ψ {\displaystyle \psi } (psi). The force equation of motion includes a component of weight: d μ d t = Y m U + g U ϕ {\displaystyle {\frac {d\mu }{dt}}={\frac {Y}{mU}}+{\frac {g}{U}}\phi } where g is the gravitational acceleration, and U is the speed.

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