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Denoising autoencoder Variational autoencoder (VAE) Autoencoder > Variations > Variational autoencoder (VAE) Variational autoencoders (VAEs) belong to the families of variational Bayesian methods. Despite the architectural similarities with basic autoencoders, VAEs are architecture with different goals and with a completely different mathematical formulation. The latent space is in this case composed by a mixture of distributions instead of a fixed vector. Given an input dataset x {\displaystyle x} characterized by an unknown probability function P ( x ) {\displaystyle P(x)} and a multivariate latent encoding vector z {\displaystyle z} , the objective is to model the data as a distribution p θ ( x ) {\displaystyle p_{\theta }(x)} , with θ {\displaystyle \theta } defined as the set of the network parameters so that p θ ( x ) = ∫ z p θ ( x , z ) d z {\displaystyle p_{\theta }(x)=\int _{z}p_{\theta }(x,z)dz} .
Fuel Fission Chemical_fuel > Nuclear > Fission The most common type of nuclear fuel used by humans is heavy fissile elements that can be made to undergo nuclear fission chain reactions in a nuclear fission reactor; nuclear fuel can refer to the material or to physical objects (for example fuel bundles composed of fuel rods) composed of the fuel material, perhaps mixed with structural, neutron moderating, or neutron reflecting materials. When some of these fuels are struck by neutrons, they are in turn capable of emitting neutrons when they break apart. This makes possible a self-sustaining chain reaction that releases energy at a controlled rate in a nuclear reactor, or at a very rapid uncontrolled rate in a nuclear weapon.
Andrzej Grzegorczyk Other papers Andrzej_Grzegorczyk > Selected publications > Other papers 199–208 Grzegorczyk, Andrzej (1974): Axiomatic theory of enumeration. In Fenstad, Jens Erik; Hinman, Peter Greayer (editors) (1974): Generalized Recursion Theory: Proceedings of the 1972 Oslo Symposium. North Holland, Amsterdam, pp.
Quantum energy level Explanation Quantum_energy > Explanation Elementary examples that show mathematically how energy levels come about are the particle in a box and the quantum harmonic oscillator. Any superposition (linear combination) of energy states is also a quantum state, but such states change with time and do not have well-defined energies. A measurement of the energy results in the collapse of the wavefunction, which results in a new state that consists of just a single energy state. Measurement of the possible energy levels of an object is called spectroscopy.
H-alpha Filter H_alpha > Filter For observing the sun, a much narrower band filter can be made from three parts: an "energy rejection filter" which is usually a piece of red glass that absorbs most of the unwanted wavelengths, a Fabry–Pérot etalon which transmits several wavelengths including one centred on the H-alpha emission line, and a "blocking filter" -a dichroic filter which transmits the H-alpha line while stopping those other wavelengths that passed through the etalon. This combination will pass only a narrow (<0.1 nm) range of wavelengths of light centred on the H-alpha emission line. The physics of the etalon and the dichroic interference filters are essentially the same (relying on constructive/destructive interference of light reflecting between surfaces), but the implementation is different (a dichroic interference filter relies on the interference of internal reflections while the etalon has a relatively large air gap).
Feasible computability Problems in NP not known to be in P or NP-complete Intractable_problem > Important open problems > Problems in NP not known to be in P or NP-complete If the problem is NP-complete, the polynomial time hierarchy will collapse to its first level (i.e., NP will equal co-NP). The best known algorithm for integer factorization is the general number field sieve, which takes time O ( e ( 64 9 3 ) ( log ⁡ n ) 3 ( log ⁡ log ⁡ n ) 2 3 ) {\displaystyle O(e^{\left({\sqrt{\frac {64}{9}}}\right){\sqrt{(\log n)}}{\sqrt{(\log \log n)^{2}}}})} to factor an odd integer n. However, the best known quantum algorithm for this problem, Shor's algorithm, does run in polynomial time. Unfortunately, this fact doesn't say much about where the problem lies with respect to non-quantum complexity classes.
Dioxygen in biological reactions Photosynthesis Dioxygen_in_biological_reactions > Photosynthesis In nature, free oxygen is produced by the light-driven splitting of water during oxygenic photosynthesis. Green algae and cyanobacteria in marine environments provide about 70% of the free oxygen produced on earth. The remainder is produced by terrestrial plants, although, for example, almost all oxygen produced in tropical forests is consumed by organisms living there.A simplified overall formula for photosynthesis is: 6CO2 + 6H2O + photons → C6H12O6 + 6O2(or simply carbon dioxide + water + sunlight → glucose + oxygen) Photolytic oxygen evolution during photosynthesis occurs via the light-dependent oxidation of water to molecular oxygen and can be written as the following simplified chemical reaction: 2H2O → 4e− + 4H+ + O2The reaction occurs in the thylakoid membranes of cyanobacteria as well as algal and plant chloroplasts and requires the energy of four photons.
Undefined (mathematics) Summary Undefined_(mathematics) As these terms are not defined in terms of other concepts, they may be referred to as "undefined terms". A function is said to be "undefined" at points outside of its domain – for example, the real-valued function f ( x ) = x {\displaystyle f(x)={\sqrt {x}}} is undefined for negative x {\displaystyle x} (i.e., it assigns no value to negative arguments). In algebra, some arithmetic operations may not assign a meaning to certain values of its operands (e.g., division by zero). In which case, the expressions involving such operands are termed "undefined".
Search Engine Approach Web_search_engines > Approach A query from a user can be a single word, multiple words or a sentence. The index helps find information relating to the query as quickly as possible. Some of the techniques for indexing, and caching are trade secrets, whereas web crawling is a straightforward process of visiting all sites on a systematic basis.
Placoid scales Drag reduction Fish_scales > Placoid scales > Shark skin > Drag reduction Frictional drag is a result of the interaction between the fluid against the shark's skin and can vary depending on how the boundary layer changes against the surface of the fish.The riblets impede the cross-stream translation of the streamwise vortices in the viscous sublayer. The mechanism is complex and not yet understood fully. Basically, the riblets inhibit the vortex formation near the surface because the vortex cannot fit in the valleys formed by the riblets.
Moon landing Scientific background Moon_landing > Scientific background To get to the Moon, a spacecraft must first leave Earth's gravity well; currently, the only practical means is a rocket. Unlike airborne vehicles such as balloons and jets, a rocket can continue accelerating in the vacuum outside the atmosphere. Upon approach of the target moon, a spacecraft will be drawn ever closer to its surface at increasing speeds due to gravity.
Fieldata References and further reading Fieldata > References and further reading (September 1960b). "Data Processing as a Tool for Generalizing Communications Systems". Transactions of the American Institute of Electrical Engineers, Part I: Communication and Electronics.
Waardenburg syndrome Cause Waardenburg's_syndrome > Cause Waardenburg syndrome is caused by mutations in any of several genes that affect the operation of neural crest cells in embryonic development. Most types of Waardenburg syndrome are caused by autosomal dominant mutations. The few that are autosomal recessive are rare.
Toll-like receptors Summary Toll-like_receptor Toll-like receptors (TLRs) are a class of proteins that play a key role in the innate immune system. They are single-pass membrane-spanning receptors usually expressed on sentinel cells such as macrophages and dendritic cells, that recognize structurally conserved molecules derived from microbes. Once these microbes have reached physical barriers such as the skin or intestinal tract mucosa, they are recognized by TLRs, which activate immune cell responses. The TLRs include TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, TLR11, TLR12, and TLR13. Humans lack genes for TLR11, TLR12 and TLR13 and mice lack a functional gene for TLR10. TLR1, TLR2, TLR4, TLR5, TLR6, and TLR10 are located on the cell membrane, whereas TLR3, TLR7, TLR8, and TLR9 are located in intracellular vesicles (because they are sensors of nucleic acids).TLRs received their name from their similarity to the protein coded by the toll gene.
S matrix From vacua Scattering_matrix > Definition in quantum field theory > In and out states > From vacua See the next section for a detailed account on how a general n-particle state is normalized. The initial and final spaces are defined by The asymptotic states are assumed to have well defined Poincaré transformation properties, i.e. they are assumed to transform as a direct product of one-particle states. This is a characteristic of a non-interacting field. From this follows that the asymptotic states are all eigenstates of the momentum operator Pμ, In particular, they are eigenstates of the full Hamiltonian, The vacuum is usually postulated to be stable and unique, The interaction is assumed adiabatically turned on and off.
Bernard H. Lavenda Camerino years Bernard_H._Lavenda > Biography > Career > Camerino years His work, summarized in Statistical Physics: A Probabilistic Approach, published by Wiley-Interscience in 1991, completes Boltzmann's principle, which expresses the entropy as the logarithm of a combinatorial factor, by showing that the entropy is the potential that determines Gauss’ law of error for which the average value is the most probable value. Just as there are frequency and degree- of-belief (Bayes' theorem) interpretations of statistical inference, the same should apply to statistical thermodynamics. The frequency interpretation applies to extensive variables, like energy and volume which can be sampled, while the degree-of-belief interpretations applies to the intensive variables, like temperature and pressure, for which sampling has no meaning.
Prostate cancer staging Cambridge Prognostic Group (CPG) Prostate_cancer_staging > Cambridge Prognostic Group (CPG) In the United Kingdom the NICE guidelines recommend using the Cambridge Prognostic Group (CPG) for categorising prostate cancer into 5 risk groups (CPG1 to CPG5). This replaces an older system which used 3 risk groups (low, medium and high risk). The CPG score is decided by looking at the Grade Group or Gleason score, the prostate specific antigen (PSA) level, and the clinical tumor stage.
Mobile cloud computing Summary Mobile_cloud_computing Mobile Cloud Computing (MCC) is the combination of cloud computing and mobile computing to bring rich computational resources to mobile users, network operators, as well as cloud computing providers. The ultimate goal of MCC is to enable execution of rich mobile applications on a plethora of mobile devices, with a rich user experience. MCC provides business opportunities for mobile network operators as well as cloud providers. More comprehensively, MCC can be defined as "a rich mobile computing technology that leverages unified elastic resources of varied clouds and network technologies toward unrestricted functionality, storage, and mobility to serve a multitude of mobile devices anywhere, anytime through the channel of Ethernet or Internet regardless of heterogeneous environments and platforms based on the pay-as-you-use principle."
Crossed quadrilateral Area of a convex quadrilateral Crossed_quadrilateral > Area of a convex quadrilateral There are various general formulas for the area K of a convex quadrilateral ABCD with sides a = AB, b = BC, c = CD and d = DA.
Neoclassical growth model Graphical analysis in phase space Ramsey_growth_model > Mathematical description > Graphical analysis in phase space By default, the first solution is meant, although the other two solutions are important to keep track of. Any optimal trajectory must follow the dynamical system. However, since the variable c {\displaystyle c} is a control variable, at each capital intensity k {\displaystyle k} , to find its corresponding optimal trajectory, we still need to find its starting consumption rate c ( 0 ) {\displaystyle c(0)} .
Norm of a quaternion Quaternions as pairs of complex numbers Hamilton_quaternions > Quaternions as pairs of complex numbers Quaternions can be represented as pairs of complex numbers. From this perspective, quaternions are the result of applying the Cayley–Dickson construction to the complex numbers. This is a generalization of the construction of the complex numbers as pairs of real numbers.
Analytica (software) Summary Analytica_(software) Analytica is a visual software developed by Lumina Decision Systems for creating, analyzing and communicating quantitative decision models. It combines hierarchical influence diagrams for visual creation and view of models, intelligent arrays for working with multidimensional data, Monte Carlo simulation for analyzing risk and uncertainty, and optimization, including linear and nonlinear programming. Its design, especially its influence diagrams and treatment of uncertainty, is based on ideas from the field of decision analysis. As a computer language, it combines a declarative (non-procedural) structure for referential transparency, array abstraction, and automatic dependency maintenance for efficient sequencing of computation.
S matrix From vacua Scattering_matrix > Definition in quantum field theory > In and out states > From vacua If a†(k) is a creation operator, its hermitian adjoint is an annihilation operator and destroys the vacuum, In Dirac notation, define as a vacuum quantum state, i.e. a state without real particles. The asterisk signifies that not all vacua are necessarily equal, and certainly not equal to the Hilbert space zero state 0. All vacuum states are assumed Poincaré invariant, invariance under translations, rotations and boosts, formally, where Pμ is the generator of translation in space and time, and Mμν is the generator of Lorentz transformations. Thus the description of the vacuum is independent of the frame of reference.
Comparison of Java and C++ Resource management Comparison_of_Java_and_C++ > Language features > Resource management In Java, object deallocation is implicitly handled by the garbage collector. A Java object's finalizer is invoked asynchronously some time after it has been accessed for the last time and before it is deallocated. Very few objects need finalizers.
Super capacitor Materials Electric_double-layer_capacitor > Materials The properties of supercapacitors come from the interaction of their internal materials. Especially, the combination of electrode material and type of electrolyte determine the functionality and thermal and electrical characteristics of the capacitors.
Central dogma of molecular biology Summary Central_dogma_of_molecular_biology There are 3 major classes of such biopolymers: DNA and RNA (both nucleic acids), and protein. There are 3 × 3 = 9 conceivable direct transfers of information that can occur between these. The dogma classes these into 3 groups of 3: three general transfers (believed to occur normally in most cells), two special transfers (known to occur, but only under specific conditions in case of some viruses or in a laboratory), and four unknown transfers (believed never to occur).
MinHash Time analysis MinHash > Algorithm > Time analysis The estimator \|Y\|/k can be computed in time O(k) from the two signatures of the given sets, in either variant of the scheme. Therefore, when ε and k are constants, the time to compute the estimated similarity from the signatures is also constant. The signature of each set can be computed in linear time on the size of the set, so when many pairwise similarities need to be estimated this method can lead to a substantial savings in running time compared to doing a full comparison of the members of each set. Specifically, for set size n the many hash variant takes O(n k) time. The single hash variant is generally faster, requiring O(n) time to maintain the queue of minimum hash values assuming n >> k.
A New Kind of Science Simple programs A_New_Kind_of_Science > Contents > Simple programs In a sense, there is not enough room in the program's definition to directly encode all the things the program can do. Therefore, simple programs can be seen as a minimal example of emergence. A logical deduction from this phenomenon is that if the details of the program's rules have little direct relationship to its behavior, then it is very difficult to directly engineer a simple program to perform a specific behavior.
Bubble Sort Use Bubble_Sort > Use Experiments by Astrachan sorting strings in Java show bubble sort to be roughly one-fifth as fast as an insertion sort and 70% as fast as a selection sort.In computer graphics bubble sort is popular for its capability to detect a very small error (like swap of just two elements) in almost-sorted arrays and fix it with just linear complexity (2n). For example, it is used in a polygon filling algorithm, where bounding lines are sorted by their x coordinate at a specific scan line (a line parallel to the x axis) and with incrementing y their order changes (two elements are swapped) only at intersections of two lines. Bubble sort is a stable sort algorithm, like insertion sort.
Tachyonic field Condensation Tachyonic_field > Condensation In quantum field theory, a tachyon is a quantum of a field—usually a scalar field—whose squared mass is negative, and is used to describe spontaneous symmetry breaking: The existence of such a field implies the instability of the field vacuum; the field is at a local maximum rather than a local minimum of its potential energy, much like a ball at the top of a hill. A very small impulse (which will always happen due to quantum fluctuations) will lead the field (ball) to roll down with exponentially increasing amplitudes: it will induce tachyon condensation. Once the tachyonic field reaches the minimum of the potential, its quanta are not tachyons any more but rather have a positive mass-squared. The Higgs boson of the standard model of particle physics is an example.Technically, the squared mass is the second derivative of the effective potential.
Locally constant Examples Locally_constant_function > Examples The converse is true for locally connected spaces, which are spaces whose connected components are open subsets. Further examples include the following: Given a covering map p: C → X , {\displaystyle p:C\to X,} then to each point x ∈ X {\displaystyle x\in X} we can assign the cardinality of the fiber p − 1 ( x ) {\displaystyle p^{-1}(x)} over x {\displaystyle x} ; this assignment is locally constant. A map from a topological space A {\displaystyle A} to a discrete space B {\displaystyle B} is continuous if and only if it is locally constant.
Indeterminate (variable) Summary Indeterminate_(variable) It is not an unknown that could be solved for. It is not a variable designating a function argument, or a variable being summed or integrated over. It is not any type of bound variable. It is just a symbol used in an entirely formal way.When used as placeholders, a common operation is to substitute mathematical expressions (of an appropriate type) for the indeterminates. By a common abuse of language, mathematical texts may not clearly distinguish indeterminates from ordinary variables.
Computer modeling In practical contexts Computational_modeling > In practical contexts Furthermore, simulation results are often aggregated into static images using various ways of scientific visualization. In debugging, simulating a program execution under test (rather than executing natively) can detect far more errors than the hardware itself can detect and, at the same time, log useful debugging information such as instruction trace, memory alterations and instruction counts. This technique can also detect buffer overflow and similar "hard to detect" errors as well as produce performance information and tuning data.
Renewable-energy economy Rationale for renewables Renewable_energy_policy > Background > Rationale for renewables Climate change, pollution, and energy insecurity are significant problems, and addressing them requires major changes to energy infrastructures. Renewable energy technologies are essential contributors to the energy supply portfolio, as they contribute to world energy security, reduce dependency on fossil fuels, and some also provide opportunities for mitigating greenhouse gases. Climate-disrupting fossil fuels are being replaced by clean, climate-stabilizing, non-depletable sources of energy: ...the transition from coal, oil, and gas to wind, solar, and geothermal energy is well under way. In the old economy, energy was produced by burning something — oil, coal, or natural gas — leading to the carbon emissions that have come to define our economy.
Dynamic recompilation Summary Dynamic_recompiler In computer science, dynamic recompilation is a feature of some emulators and virtual machines, where the system may recompile some part of a program during execution. By compiling during execution, the system can tailor the generated code to reflect the program's run-time environment, and potentially produce more efficient code by exploiting information that is not available to a traditional static compiler.
Visual Turing Test Example Visual_Turing_Test > Example Detailed example sequences can be found here.
Cross-training In mixed martial arts Cross-training > In general sports > In mixed martial arts In mixed martial arts and self-defense, cross-training refers to training in multiple martial arts or fighting systems to become proficient in all the phases of unarmed combat. This training is meant to overcome the shortcomings of one style by practicing another style which is strong in the appropriate area. A typical combination involves a striking-based art such as Muay Thai, combined with a grappling-based art such as wrestling and Brazilian Jiu-Jitsu. Many hybrid martial arts can be considered derivatives of such cross-training.Modern mixed martial-arts training generally involves cross-training in the different aspects and ranges of fighting.
CRISPR gene editing CRISPR-directed integrases CRISPR_gene_editing > Applications > By technique > CRISPR-directed integrases Combination of CRISPR-Cas9 with integrases enabled a technique for large edits without problematic double-stranded breaks, as demonstrated with PASTE in 2022. The researchers reported it could be used to deliver genes as long as 36,000 DNA base pairs to several types of human cells and thereby potentially for treating diseases caused by a large number of mutations.
Monte Carlo localization Sensor update Monte_Carlo_localization > Sensor update When the robot senses its environment, it updates its particles to more accurately reflect where it is. For each particle, the robot computes the probability that, had it been at the state of the particle, it would perceive what its sensors have actually sensed. It assigns a weight w t {\displaystyle w_{t}^{}} for each particle proportional to the said probability. Then, it randomly draws M {\displaystyle M} new particles from the previous belief, with probability proportional to w t {\displaystyle w_{t}^{}} .
GeneRIF Summary GeneRIF A GeneRIF or Gene Reference Into Function is a short (255 characters or fewer) statement about the function of a gene. GeneRIFs provide a simple mechanism for allowing scientists to add to the functional annotation of genes described in the Entrez Gene database. In practice, function is constructed quite broadly. For example, there are GeneRIFs that discuss the role of a gene in a disease, GeneRIFs that point the viewer towards a review article about the gene, and GeneRIFs that discuss the structure of a gene.
Aerobiology Experimental methods Aerobiology > Experimental methods There have been many studies performed to understand real-life dispersal patterns of pollen and spores. To collect samples, studies often use a volumetric spore trap such as a Hirst-type sampler. Particles stick to a sampling strip and then can be inspected under a microscope.
Species flock Speciation process Cryptic_species > Evolution and ecology > Speciation process For example, yellow-spotted "fire salamanders" in the genus Salamandra, formerly all classified as one species S. salamandra, are not monophyletic: the Corsican fire salamander's closest relative has been shown to be the entirely black Alpine salamander. In such cases, similarity has arisen from convergent evolution. Hybrid speciation can lead to unclear species boundaries through a process of reticulate evolution, in which species have two parent species as their most recent common ancestors.
Scientific theories Example: Relativity Scientific_theories > Modification and improvement > Example: Relativity Yet unless the energy is vast, its relativistic effects of contracting space and slowing time are negligible when merely predicting motion. Although general relativity is embraced as the more explanatory theory via scientific realism, Newton's theory remains successful as merely a predictive theory via instrumentalism. To calculate trajectories, engineers and NASA still uses Newton's equations, which are simpler to operate.
ZETA (fusion reactor) Conceptual development ZETA_(fusion_reactor) > Conceptual development The basic understanding of nuclear fusion was developed during the 1920s as physicists explored the new science of quantum mechanics. George Gamow's 1928 exploration of quantum tunnelling demonstrated that nuclear reactions could take place at lower energies than classical theory predicted. Using this theory, in 1929 Fritz Houtermans and Robert Atkinson demonstrated that expected reaction rates in the core of the Sun supported Arthur Eddington's 1920 suggestion that the Sun is powered by fusion.In 1934, Mark Oliphant, Paul Harteck and Ernest Rutherford were the first to achieve fusion on Earth, using a particle accelerator to shoot deuterium nuclei into a metal foil containing deuterium, lithium or other elements. This allowed them to measure the nuclear cross section of various fusion reactions, and determined that the deuterium-deuterium reaction occurred at a lower energy than other reactions, peaking at about 100,000 electronvolts (100 keV).This energy corresponds to the average energy of particles in a gas heated to thousands of millions of kelvins.
Bode's sensitivity integral Summary Bode's_sensitivity_integral The controller attempts to cause the process output, y, to track the reference input, r. Disturbances, d, and measurement noise, n, may cause undesired deviations of the output. Loop gain is defined by L(s) = P(s)C(s).
Coupled mode theory Formulation Coupled_mode_theory > Formulation The formulation of the coupled mode theory is based on the development of the solution to an electromagnetic problem into modes. Most of the time it is eigenmodes which are taken in order to form a complete base. The choice of the basis and the adoption of certain hypothesis like parabolic approximation differs from formulation to formulation. The classification proposed by of the different formulation is as follows: The choice of starting differential equation.
Peak signal-to-noise ratio Quality estimation with PSNR Peak_signal-to-noise_ratio > Quality estimation with PSNR Typical values for the PSNR in lossy image and video compression are between 30 and 50 dB, provided the bit depth is 8 bits, where higher is better. The processing quality of 12-bit images is considered high when the PSNR value is 60 dB or higher. For 16-bit data typical values for the PSNR are between 60 and 80 dB. Acceptable values for wireless transmission quality loss are considered to be about 20 dB to 25 dB.In the absence of noise, the two images I and K are identical, and thus the MSE is zero. In this case the PSNR is infinite (or undefined, see Division by zero).
Health information management Methods to ensure Data Quality Health_information_management > Elements > Practices > Methods to ensure Data Quality Consistency: The value of the data should be reliable and the same across applications. Currency: The data should be up to date. A datum value is up to date if it is current for a specific point in time.
Pythagoras In mathematics Pythagoras > Attributed discoveries > In mathematics Cicero rejected this story as spurious because of the much more widely held belief that Pythagoras forbade blood sacrifices. Porphyry attempted to explain the story by asserting that the ox was actually made of dough.The Pythagorean theorem was known and used by the Babylonians and Indians centuries before Pythagoras, but he may have been the first to introduce it to the Greeks. Some historians of mathematics have even suggested that he—or his students—may have constructed the first proof.
Computer architectures Performance Computer_design > Design goals > Performance Although benchmarking shows strengths, it shouldn't be how you choose a computer. Often the measured machines split on different measures. For example, one system might handle scientific applications quickly, while another might render video games more smoothly. Furthermore, designers may target and add special features to their products, through hardware or software, that permit a specific benchmark to execute quickly but do not offer similar advantages to general tasks.
Micro RNA Human homolog microRNA-205 Micro_RNA > Disease > Heart disease > Human homolog microRNA-205 The human homolog of miR-712 was found on the RN45s homolog gene, which maintains similar miRNAs to mice. MiR-205 of humans share similar sequences with miR-712 of mice and is conserved across most vertebrates. MiR-205 and miR-712 also share more than 50% of the cell signaling targets, including TIMP3.When tested, d-flow decreased the expression of XRN1 in humans as it did in mice endothelial cells, indicating a potentially common role of XRN1 in humans.
Optimal Control General method Optimal_Control > General method The question is, how should the driver press the accelerator pedal in order to minimize the total traveling time? In this example, the term control law refers specifically to the way in which the driver presses the accelerator and shifts the gears. The system consists of both the car and the road, and the optimality criterion is the minimization of the total traveling time.
SciGraph Technology SciGraph > Technology SciGraph constitutes 1.5 to 2 billion triples where a triple is formatted as "subject-predicate-object" and could link any subject or concept through a predicate (verb) to another object, demonstrating the type of relationship that exists between them. Its graph structure is used by other academic search engines such as Semantic Scholar. SciGraph collects data from Springer Nature and its partners from the scholarly domain as well as funders, research projects, conferences, affiliations, and publications.
Primary energy resource Usable energy Primary_energy > Usable energy Primary energy sources are transformed in energy conversion processes to more convenient forms of energy that can directly be used by society, such as electrical energy, refined fuels, or synthetic fuels such as hydrogen fuel. In the field of energetics, these forms are called energy carriers and correspond to the concept of "secondary energy" in energy statistics.
Chronic pyelonephritis Summary Kidney_infections Pyelonephritis is inflammation of the kidney, typically due to a bacterial infection. Symptoms most often include fever and flank tenderness. Other symptoms may include nausea, burning with urination, and frequent urination. Complications may include pus around the kidney, sepsis, or kidney failure.It is typically due to a bacterial infection, most commonly Escherichia coli.
Quantitative social research Justice Quantitative_social_research > Ethics > Justice The principle of justice states the benefits of research should be distributed fairly. The definition of fairness used is case-dependent, varying between "(1) to each person an equal share, (2) to each person according to individual need, (3) to each person according to individual effort, (4) to each person according to societal contribution, and (5) to each person according to merit."
Proximate cause But-for test Proximate_cause > But-for test The injury or illness is due to a design hazard, with each having been found to have sold the same type of product in a manner that made it unreasonably dangerous, there is inability to identify the specific manufacturer of the product or products that brought about the Plaintiff's injury or illness and there are enough manufacturers of the fungible product joined in the lawsuit, to represent a substantial share of the market. Any damages would then be divided according to the market share ratio.Since but-for causation is very easy to show and does not assign culpability (but for the rain, you would not have crashed your car – the rain is not morally or legally culpable but still constitutes a cause), there is a second test used to determine if an action is close enough to a harm in a "chain of events" to be a legally culpable cause of the harm. This test is called proximate cause, from the Latin proxima causa.
Artificial intelligence of things Artificial Intelligence Through Medical Devices Artificial_intelligence_of_things > Artificial Intelligence Through Medical Devices As defined by the 21st Century Cures Act in 2016, a medical device is a device that performs a function in healthcare with the intention of using it "in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease, in man or other animals, or intended to affect the structure or any function of the body of man or other animals".Under the Federal Food, Drug, and Cosmetic Act, all AI systems falling within this definition are regulated by the FDA. Medical devices are classified into three classes by the FDA based on their uses and risks. The higher the risk is, the stricter the control. The Class I category includes devices with the smallest risk and Class III has the greatest risk.
Query Rewriting Summary Query_Rewriting For example, filtering on fields A and B, or cross joining R and S can be done in any order, but there can be a performance difference. Multiple operations may be combined, and operation orders may be altered. The result of query rewriting may not be at the same abstraction level or application programming interface (API) as the original set of queries (though often is).
Integration by reduction formulae Examples Integration_by_reduction_formulae > How to compute the integral > Examples Below are examples of the procedure.
Rangekeeper Servo speed stabilization Rangekeeper > Mechanisms > Servo speed stabilization 1A computer integrator discs required a particularly elaborate system to provide constant and precise drive speeds. They used a motor with its speed regulated by a clock escapement, cam-operated contacts, and a jeweled-bearing spur-gear differential.
Kinematic theory of diffraction Approximations Diffraction_formalism > Approximations At some point on the screen the path length to one side of the object is given by the Pythagorean theorem S = L 2 + ( x + a / 2 ) 2 {\displaystyle S={\sqrt {L^{2}+(x+a/2)^{2}}}} If we now consider the situation where L ≫ ( x + a / 2 ) {\displaystyle L\gg (x+a/2)} , the path length becomes This is the Fresnel approximation. To further simplify things: If the diffracting object is much smaller than the distance L {\displaystyle L} , the last term will contribute much less than a wavelength to the path length, and will then not change the phase appreciably. That is a 2 L ≪ λ {\displaystyle {\frac {a^{2}}{L}}\ll \lambda } . The result is the Fraunhofer approximation, which is only valid very far away from the object Depending on the size of the diffraction object, the distance to the object and the wavelength of the wave, the Fresnel approximation, the Fraunhofer approximation or neither approximation may be valid. As the distance between the measured point of diffraction and the obstruction point increases, the diffraction patterns or results predicted converge towards those of Fraunhofer diffraction, which is more often observed in nature due to the extremely small wavelength of visible light.
Virginia Satir Process of Change Model Virginia_Satir > Process of Change Model The third stage of change is practice and integration. In this stage new ideas are being implemented and individuals are figuring out what works best. Like any other skill, it requires patience and practice.
Orders of magnitude (numbers) 100 Order_of_magnitude_(numbers) > 100 Mathematics: the number system understood by ternary computers, the ternary system, uses 3 digits: 0, 1, and 2. Religion: three manifestations of God in the Christian Trinity. Mathematics: π ≈ 3.141592653589793238, the ratio of a circle's circumference to its diameter.
Shortest-distance problems Shortest path in stochastic time-dependent networks All-pairs_shortest_path_problem > Shortest path in stochastic time-dependent networks One possible and common answer to this question is to find a path with the minimum expected travel time. The main advantage of using this approach is that efficient shortest path algorithms introduced for the deterministic networks can be readily employed to identify the path with the minimum expected travel time in a stochastic network. However, the resulting optimal path identified by this approach may not be reliable, because this approach fails to address travel time variability.
Constructive set theory Regularity implies PEM Constructive_set_theory > Subtheories of ZF > Choice functions > Regularity implies PEM The axiom of regularity states that for every inhabited set s {\displaystyle s} , there exists an element t {\displaystyle t} in s {\displaystyle s} , which shares no elements with s {\displaystyle s} . As opposed to the axiom of choice, this existence claim reaches for an element of every inhabited set, i.e. the "domain" are all inhabited sets. Its formulation does not involve a unique existence claim but instead guarantees a set with a specific property. As the axiom correlates membership claims at different rank, the axiom also ends up implying P E M {\displaystyle {\mathrm {PEM} }}: The proof from choice above had used a particular set { a , b } {\displaystyle \{a,b\}} .
Soybean cyst nematode Disease cycle Soybean_cyst_nematode > Disease cycle Soybean cyst nematodes are so devastating due to their life cycle being so efficient for multiplication. They have six life stages, which is the norm for all nematodes. These stages include: egg, juvenile (J1-J4), and adult and can complete multiple cycles within a single growing season. The SCNs makes its first molt while still inside the egg going from a juvenile 1 (J1) to a juvenile 2 (J2).
Kermeta Philosophy Kermeta > Philosophy a concrete syntax that fits well to model and metamodel writing. two paradigms: the object, and the model. a bridge towards the Eclipse ECore formalism
Amphetamine Physical Amphetamine > Adverse effects > Physical Cardiovascular side effects can include hypertension or hypotension from a vasovagal response, Raynaud's phenomenon (reduced blood flow to the hands and feet), and tachycardia (increased heart rate). Sexual side effects in males may include erectile dysfunction, frequent erections, or prolonged erections. Gastrointestinal side effects may include abdominal pain, constipation, diarrhea, and nausea. Other potential physical side effects include appetite loss, blurred vision, dry mouth, excessive grinding of the teeth, nosebleed, profuse sweating, rhinitis medicamentosa (drug-induced nasal congestion), reduced seizure threshold, tics (a type of movement disorder), and weight loss.
Scale (geography) Scale effect Scale_(geography) > Scale effect The concept of scale is central to geography. To study any geographical phenomenon, one must first determine the scale or resolution, because different scales or resolutions may result in different observations and hence different conclusions. This problem is called scale effect or scale dependency. For example, the answer to the famous question "How Long Is the Coast of Britain" is highly dependent on the choice of cartographic scales. In cartography and spatial analysis, scale effect and zoning effect (different ways of zoning lead to different statistical outcomes) conbimed can lead to modifiable areal unit problem (MAUP).
Lava filter Constantly submerged lavafilters Lava_filter > Types of systems > Constantly submerged lavafilters In addition to water-purifying (de-nutrifying) plants, plants that supply oxygen, and shade are also added in ecologic water catchments, ponds, ... This to allow a complete ecosystem to form. Finally, in addition to plants, locally grown bacteria and non-predatory fish are also added to eliminate pests. The bacteria are usually grown locally by submerging straw in water and allowing it to form bacteria (arriving from the surrounding atmosphere).
Cel animation Animation loops Classical_animation > Techniques > Animation loops Creating animation loops or animation cycles is a labor-saving technique for animating repetitive motions, such as a character walking or a breeze blowing through the trees. In the case of walking, the character is animated taking a step with its right foot, then a step with its left foot. The loop is created so that, when the sequence repeats, the motion is seamless. In general, they are used only sparingly by productions with moderate or high budgets. Ryan Larkin's 1969 Academy Award-nominated National Film Board of Canada short Walking makes creative use of loops. In addition, a promotional music video from Cartoon Network's Groovies featuring the Soul Coughing song "Circles" poked fun at animation loops as they are often seen in The Flintstones, in which Fred and Barney (along with various Hanna-Barbera characters that aired on Cartoon Network), supposedly walking in a house, wonder why they keep passing the same table and vase over and over again.
DISC1 Schizophrenia DISC1 > Clinical implications > Schizophrenia Schizophrenia affects 1% of the general population and is highly heritable, providing an indication of a genetic basis. DISC1 has been associated with neurological abnormalities such as delusions, deficits in long term and working memory, diminution of gray matter volume in hippocampal and prefrontal regions. These abnormalities are also seen as symptoms of schizophrenia. As DISC1 function is involved in neurogenesis and neuroplasticity, vulnerability to schizophrenia may involve dysfunction in the hippocampus, a brain region in which adult neurogenesis occurs. Mice expressing the dominant-negative form of DISC1 have been shown to be increasingly susceptible to impaired reality testing, a hallmark of psychosis.
Air-core transformer Cooling Power_transformer > Construction > Cooling The tank of liquid-filled transformers often has radiators through which the liquid coolant circulates by natural convection or fins. Some large transformers employ electric fans for forced-air cooling, pumps for forced-liquid cooling, or have heat exchangers for water-cooling.
Lorentz forces Lorentz force and Faraday's law of induction Lorentz_equation > Lorentz force and Faraday's law of induction However, there are cases where Faraday's law is either inadequate or difficult to use, and application of the underlying Lorentz force law is necessary. See inapplicability of Faraday's law.
NMR crystallography Dipolar couplings-based approach Nuclear_magnetic_resonance_crystallography > Dipolar couplings-based approach In NMR crystallography the observed spins in case of organic molecules would often be spin-1/2 nuclei of moderate frequency (13C, 15N, 31P, etc.). I.e. 1H is excluded due to its large magnetogyric ratio and high spin concentration leading to a network of strong homonuclear dipolar couplings. There are two solutions with respect to 1H: 1H spin diffusion experiments (see below) and specific labelling with 2H spins (spin = 1).
C symmetry In classical fields C_symmetry > Informal overview > In classical fields Gauge symmetry, in this geometric setting, is a statement that, as one moves around on the circle, the coupled object must also transform in a "circular way", tracking in a corresponding fashion. More formally, one says that the equations must be gauge invariant under a change of local coordinate frames on the circle. For U(1), this is just the statement that the system is invariant under multiplication by a phase factor e i ϕ ( x ) {\displaystyle e^{i\phi (x)}} that depends on the (space-time) coordinate x . {\displaystyle x.} In this geometric setting, charge conjugation can be understood as the discrete symmetry z = ( x + i y ) ↦ z ¯ = ( x − i y ) {\displaystyle z=(x+iy)\mapsto {\overline {z}}=(x-iy)} that performs complex conjugation, that reverses the sense of direction around the circle.
Attention Restoration Theory Summary Attention_Restoration_Theory The theory was developed by Rachel and Stephen Kaplan in the 1980s in their book The experience of nature: A psychological perspective, and has since been found by others to hold true in medical outcomes as well as intellectual task attention, as described below. Berman et al. discuss the foundation of the attention restoration theory (ART). "ART is based on past research showing the separation of attention into two components: involuntary attention, where attention is captured by inherently intriguing or important stimuli, and voluntary or directed attention, where attention is directed by cognitive-control processes."
Logology (science) Artificial intelligence Logology_(science) > Science > Artificial intelligence It has been quipped that "AI is whatever hasn't been done yet. "Since 1950, when Alan Turing proposed what has come to be called the "Turing test," there has been speculation whether machines such as computers can possess intelligence; and, if so, whether intelligent machines could become a threat to human intellectual and scientific ascendancy—or even an existential threat to humanity. John Searle points out common confusion about the correct interpretation of computation and information technology.
Molecular diffusion Summary Molecular_diffusion Consider two systems; S1 and S2 at the same temperature and capable of exchanging particles. If there is a change in the potential energy of a system; for example μ1>μ2 (μ is Chemical potential) an energy flow will occur from S1 to S2, because nature always prefers low energy and maximum entropy. Molecular diffusion is typically described mathematically using Fick's laws of diffusion.
Nephrotic syndrome Differential diagnosis Nephrotic_syndrome > Diagnosis > Differential diagnosis Some symptoms that are present in nephrotic syndrome, such as edema and proteinuria, also appear in other illnesses. Therefore, other pathologies need to be excluded in order to arrive at a definitive diagnosis. Edema: in addition to nephrotic syndrome there are two other disorders that often present with edema; these are heart failure and liver failure. Congestive heart failure can cause liquid retention in tissues as a consequence of the decrease in the strength of ventricular contractions.
Bogosort Related algorithms Bogosort > Related algorithms Miracle sort A sorting algorithm that checks if the array is sorted until a miracle occurs. It continually checks the array until it is sorted, never changing the order of the array. Because the order is never altered, the algorithm has a hypothetical time complexity of O(∞), but it can still sort through events such as miracles or single-event upsets. Particular care must be taken in the implementation of this algorithm as optimizing compilers may simply transform it into a while(true) loop. However, the best case is O(n), which happens on a sorted list.
Protein-RNA interaction Alternative splicing Protein-RNA_interaction > Function > RNA processing and modification > Alternative splicing These proteins then recruit splicesomal proteins to this target site. SR proteins are also well known for their role in alternative splicing through the recruitment of snRNPs that form the splicesome, namely U1 snRNP and U2AF snRNP. However, RBPs are also part of the splicesome itself.
Complex Adaptive System Overview Complex_Adaptive_System > Overview Softer theories use natural language and narratives that may be imprecise, and agents are subjects having both tangible and intangible properties. Examples of hard complexity theories include Complex Adaptive Systems (CAS) and Viability Theory, and a class of softer theory is Viable System Theory. Many of the propositional consideration made in hard theory are also of relevance to softer theory.
Alan Jeffrey Giacomin Research Alan_Jeffrey_Giacomin > Research Professor Giacomin and his group have published on the rheology of polymeric liquids, and especially on their behaviours in large-amplitude oscillatory shear flow (LAOS) (see Self-assembly of nanoparticles). Specifically, Giacomin has explored the role of polymer orientation in LAOS. Giacomin developed the conversions from standardized polymer durometer hardness to Young's modulus using linear elastic indentation mechanics.
Nervous system network models Brain connectivity model Nervous_system_network_models > Nervous system models > Brain connectivity model In the structural brain connectivity type, the connectivity is a sparse and directed graph. The functional brain connectivity has bidirectional graphs. The effective brain connectivity is bidirectional with interactive cause and effect relationships.
Commercial eye tracking Practice Eye_Tracking > Practice A great deal of research has gone into studies of the mechanisms and dynamics of eye rotation, but the goal of eye tracking is most often to estimate gaze direction. Users may be interested in what features of an image draw the eye, for example. It is important to realize that the eye tracker does not provide absolute gaze direction, but rather can measure only changes in gaze direction. To determine precisely what a subject is looking at, some calibration procedure is required in which the subject looks at a point or series of points, while the eye tracker records the value that corresponds to each gaze position.
Capsule neural network Summary Capsule_neural_network This vector is similar to what is done for example when doing classification with localization in CNNs. Among other benefits, capsnets address the "Picasso problem" in image recognition: images that have all the right parts but that are not in the correct spatial relationship (e.g., in a "face", the positions of the mouth and one eye are switched). For image recognition, capsnets exploit the fact that while viewpoint changes have nonlinear effects at the pixel level, they have linear effects at the part/object level. This can be compared to inverting the rendering of an object of multiple parts.
Transmetalation Summary Transmetalation Transmetalation (alt. spelling: transmetallation) is a type of organometallic reaction that involves the transfer of ligands from one metal to another. It has the general form: M1–R + M2–R′ → M1–R′ + M2–Rwhere R and R′ can be, but are not limited to, an alkyl, aryl, alkynyl, allyl, halogen, or pseudohalogen group. The reaction is usually an irreversible process due to thermodynamic and kinetic reasons.
Concurrent Pascal Language description Concurrent_Pascal > Language description A built in data type, the queue, together with operations delay and continue, are used for scheduling within monitors. Each variable of type queue can hold one process. If many processes are to be delayed in a monitor, multiple queue variables, usually organized as an array, must be provided.
Anomeric effect Overcoming the anomeric effect Anomeric_effect > Influences > Overcoming the anomeric effect When a large substituent is added to the spiroketal backbone, as seen in the lower left, the strain from having this large substituent, R, in the axial position is greatly destabilizing to the molecule. In the molecule on the lower right, R is now in the equatorial position, which no longer causes destabilization on the molecule. Therefore, without substituents, the upper equilibrium reaction is favored on the left hand side, while the lower equilibrium is favored on the right hand side, simply from the addition of a large, destabilizing substituent.
Resultant Number theory Resultant > Other applications > Number theory Every element of β ∈ K ( α ) {\displaystyle \beta \in K(\alpha )} may be written as β = Q ( α ) , {\displaystyle \beta =Q(\alpha ),} where Q {\displaystyle Q} is a polynomial. Then β {\displaystyle \beta } is a root of res x ⁡ ( P ( x ) , z − Q ( x ) ) , {\displaystyle \operatorname {res} _{x}(P(x),z-Q(x)),} and this resultant is a power of the minimal polynomial of β . {\displaystyle \beta .}
Super refraction Radar Super_refraction > Radar Anomalous Propagation is different from ground clutter, ocean reflections (sea clutter), biological returns from birds and insects, debris, chaff, sand storms, volcanic eruption plumes, and other non-precipitation meteorological phenomena. Ground and sea clutters are permanent reflection from fixed areas on the surface with stable reflective characteristics. Biological scatterer gives weak echoes over a large surface.
Formal Lie group The formal group ring of a formal group law Formal_Lie_group > The formal group ring of a formal group law The formal group ring of a formal group law is a cocommutative Hopf algebra analogous to the group ring of a group and to the universal enveloping algebra of a Lie algebra, both of which are also cocommutative Hopf algebras. In general cocommutative Hopf algebras behave very much like groups. For simplicity we describe the 1-dimensional case; the higher-dimensional case is similar except that notation becomes more involved.
Steinhaus–Johnson–Trotter algorithm Even's speedup Steinhaus–Johnson–Trotter_algorithm > Algorithm > Even's speedup A subsequent improvement by Shimon Even provides an improvement to the running time of the algorithm by storing additional information for each element in the permutation: its position, and a direction (positive, negative, or zero) in which it is currently moving (essentially, this is the same information computed using the parity of the permutation in Johnson's version of the algorithm). Initially, the direction of the number 1 is zero, and all other elements have a negative direction: At each step, the algorithm finds the greatest element with a nonzero direction, and swaps it in the indicated direction: If this causes the chosen element to reach the first or last position within the permutation, or if the next element in the same direction is greater than the chosen element, the direction of the chosen element is set to zero: After each step, all elements greater than the chosen element (which previously had direction zero) have their directions set to indicate motion toward the chosen element. That is, positive for all elements between the start of the permutation and the chosen element, and negative for elements toward the end.
Lithium atom Summary Lithium_atom A lithium atom is an atom of the chemical element lithium. Stable lithium is composed of three electrons bound by the electromagnetic force to a nucleus containing three protons along with either three or four neutrons, depending on the isotope, held together by the strong force. Similarly to the case of the helium atom, a closed-form solution to the Schrödinger equation for the lithium atom has not been found. However, various approximations, such as the Hartree–Fock method, can be used to estimate the ground state energy and wavefunction of the atom. The quantum defect is a value that describes the deviation from hydrogenic energy levels.
List of character tables for chemically important 3D point groups Notation Point_group_character_tables > Notation The symbol i used in the body of the table denotes the imaginary unit: i 2 = −1. Used in a column heading, it denotes the operation of inversion. A superscripted uppercase "C" denotes complex conjugation. The two rightmost columns indicate which irreducible representations describe the symmetry transformations of the three Cartesian coordinates (x, y and z), rotations about those three coordinates (Rx, Ry and Rz), and functions of the quadratic terms of the coordinates(x2, y2, z2, xy, xz, and yz). A further column is included in some tables, such as those of Salthouse and Ware For example, The last column relates to cubic functions which may be used in applications regarding f orbitals in atoms.
Metrication opposition Tradition Metrication_opposition > Political arguments > Tradition Traditionalists consider the retention of traditional non-metric units as a form of traditionalism, valuing historic usage spanning centuries. Non-metric units often have had different values in different times and places, and some units such as the stone even had different definitions depending on the type of object measured. At the time of the French Revolution there were over 5000 different foot measures. The current UK imperial system is based on the Weights and Measures Act 1824, dating from about 30 years after the founding of the metric system, and some of its units differ very significantly from the United States customary units of the same name.
Multiaxial diagnosis DSM-II (1968) Multiaxial_diagnosis > Early versions (20th century) > DSM-II (1968) The idea that personality disorders did not involve emotional distress was discarded.An influential 1974 paper by Robert Spitzer and Joseph L. Fleiss demonstrated that the second edition of the DSM (DSM-II) was an unreliable diagnostic tool. Spitzer and Fleiss found that different practitioners using the DSM-II rarely agreed when diagnosing patients with similar problems. In reviewing previous studies of eighteen major diagnostic categories, Spitzer and Fleiss concluded that "there are no diagnostic categories for which reliability is uniformly high. Reliability appears to be only satisfactory for three categories: mental deficiency, organic brain syndrome (but not its subtypes), and alcoholism. The level of reliability is no better than fair for psychosis and schizophrenia and is poor for the remaining categories".
Push-down automaton Formal definition Push-down_automaton > Formal definition In general pushdown automata are nondeterministic meaning that in a given instantaneous description ( p , w , β ) {\displaystyle (p,w,\beta )} there may be several possible steps. Any of these steps can be chosen in a computation. With the above definition in each step always a single symbol (top of the stack) is popped, replacing it with as many symbols as necessary.

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