Split (1)

train · 253k rows

page_content stringlengths 51 3.15k
Distributed search Dynamic assignment Distributed_search > Types > Dynamic assignment With this type of policy, a central server assigns new URLs to different crawlers dynamically. This allows the central server to, for instance, dynamically balance the load of each crawler.With dynamic assignment, typically the systems can also add or remove downloader processes. The central server may become the bottleneck, so most of the workload must be transferred to the distributed crawling processes for large crawls. There are two configurations of crawling architectures with dynamic assignments that have been described by Shkapenyuk and Suel: A small crawler configuration, in which there is a central DNS resolver and central queues per Web site, and distributed downloaders. A large crawler configuration, in which the DNS resolver and the queues are also distributed.
Natural resource economics Comprehensive natural resource models Resource_economics > Perpetual resources vs. exhaustibility > Comprehensive natural resource models Harrison Brown and associates stated that humanity will process lower and lower grade "ore". Iron will come from low-grade iron-bearing material such as raw rock from anywhere in an iron formation, not much different from the input used to make taconite pellets in North America and elsewhere today. As coking coal reserves decline, pig iron and steel production will use non-coke-using processes (i.e. electric steel). The aluminum industry could shift from using bauxite to using anorthosite and clay.
Angiotensin converting enzyme inhibitors Renin–angiotensin–aldosterone system ACE_inhibitor > Mechanism of action > Renin–angiotensin–aldosterone system The renin–angiotensin–aldosterone system is a major blood pressure regulating mechanism. Markers of electrolyte and water imbalance in the body such as hypotension, low distal tubule sodium concentration, decreased blood volume and high sympathetic tone trigger the release of the enzyme renin from the cells of juxtaglomerular apparatus in the kidney. Renin activates a circulating liver derived prohormone angiotensinogen by proteolytic cleavage of all but its first ten amino acid residues known as angiotensin I. ACE (angiotensin converting enzyme) then removes a further two residues, converting angiotensin I into angiotensin II. ACE is found in the pulmonary circulation and in the endothelium of many blood vessels. The system increases blood pressure by increasing the amount of salt and water the body retains, although angiotensin is also very good at causing the blood vessels to tighten (a potent vasoconstrictor).
Biostatistics Quantitative genetics Biostatistics > Applications > Quantitative genetics So, the concept of Genomic Selection (GS) arises in order to use all molecular markers in the selection and allow the prediction of the performance of candidates in this selection. The proposal is to genotype and phenotype a training population, develop a model that can obtain the genomic estimated breeding values (GEBVs) of individuals belonging to a genotype and but not phenotype population, called testing population. This kind of study could also include a validation population, thinking in the concept of cross-validation, in which the real phenotype results measured in this population are compared with the phenotype results based on the prediction, what used to check the accuracy of the model. As a summary, some points about the application of quantitative genetics are: This has been used in agriculture to improve crops (Plant breeding) and livestock (Animal breeding). In biomedical research, this work can assist in finding candidates gene alleles that can cause or influence predisposition to diseases in human genetics
Myelocortical multiple sclerosis Separated variants Inflammatory_demyelinating_diseases_of_the_CNS > Separated variants Several previous MS variants have been recently separated from MS after the discovery of a specific auto-antibody. Those autoantibodies are currently anti-AQP4, anti-MOG and some anti-Neurofascins.The pathogenic mechanism is usually not related to the clinical course. Therefore, one given pathogenic underlying condition can yield several clinical diseases, and one disease can be produced by several pathogenic conditions.These conditions can appear as Neuromyelitis optica (NMO), and its associated "spectrum of disorders" (NMOSD), currently considered a common syndrome for several separated diseases but with some still idiopathic subtypes. Some researchers think that there could exist an overlapping between Anti-NMDA receptor encephalitis cases and neuromyelitis optica or acute disseminated encephalomyelitis.
Glossary of operating systems terms C Glossary_of_operating_systems_terms > C Doeppner (2011) mentions them (p. 3), but only to prove that operating systems "are not a solved problem" and that even if the day of the dedicated PC is waning, cloud computing has created an entirely new opportunity for o/s development ala sharing, networks, memory, parallelism, etc. Gagne (2012) adds that in addition to numerous traditional o/s's at cloud warehouses, Virtual machine o/s (VMMs), Eucalyptus, Vware, vCloud Director and others are being developed specifically for cloud management with numerous traditional o/s features (security, threads, file and memory management, guis, etc.) (p.
Hershey–Chase experiment Experiment and conclusions Hershey–Chase_experiment > Methods and results > Experiment and conclusions They determined that a protective protein coat was formed around the bacteriophage, but that the internal DNA is what conferred its ability to produce progeny inside a bacterium. They showed that, in growth, protein has no function, while DNA has some function. They determined this from the amount of radioactive material remaining outside of the cell.
Table of elements Metallicity Periodic_Table > Periodic trends > Metallicity They tend to be reactive towards metals, except for the noble gases, which are inert towards most substances. They are brittle when solid as their atoms are held tightly in place. They are less dense and conduct electricity poorly, because there are no mobile electrons.
Black body spectrum Further explanation Black-body_radiation > Theory > Further explanation Secondly, shorter wavelengths have more energy associated per mode. The two factors combined give the characteristic maximum wavelength.
Chemical Kinetics Physical state Chemical_reaction_kinetics > Factors affecting reaction rate > Physical state Vigorous shaking and stirring may be needed to bring the reaction to completion. This means that the more finely divided a solid or liquid reactant the greater its surface area per unit volume and the more contact it with the other reactant, thus the faster the reaction. To make an analogy, for example, when one starts a fire, one uses wood chips and small branches — one does not start with large logs right away. In organic chemistry, on water reactions are the exception to the rule that homogeneous reactions take place faster than heterogeneous reactions ( are those reactions in which solute and solvent not mix properly)
Foundations of statistics Illustrative quotations Foundations_of_statistics > Bayesian inference versus frequentist inference > Illustrative quotations "Statisticians are often put in a setting reminiscent of Arrow’s paradox, where we are asked to provide estimates that are informative and unbiased and confidence statements that are correct conditional on the data and also on the underlying true parameter." (These are conflicting requirements.) "Formal inferential aspects are often a relatively small part of statistical analysis" "The two philosophies, Bayesian and frequentist, are more orthogonal than antithetical." "A hypothesis that may be true is rejected because it has failed to predict observable results that have not occurred. This seems a remarkable procedure."
Random dynamical system Motivation 2: Connection to Markov Chain Random_dynamical_system > Motivation 2: Connection to Markov Chain random transformations? Yes, it can, but not unique. The proof for existence is similar with Birkhoff–von Neumann theorem for doubly stochastic matrix.
List of terms relating to algorithms and data structures W List_of_terms_relating_to_algorithms_and_data_structures > W walk weak cluster weak-heap weak-heap sort weight-balanced tree weighted, directed graph weighted graph window witness work-depth model work-efficient work-preserving worst case worst-case cost worst-case minimum access Wu's line algorithm
Estrone sulfotransferase Reaction Estrogen_sulfotransferase > Reaction In enzymology, an EST is an enzyme that catalyzes the following chemical reaction: 3'-phosphoadenylyl sulfate + estrone ⇌ {\displaystyle \rightleftharpoons } adenosine 3',5'-bisphosphate + estrone 3-sulfateThus, the two substrates of this enzyme are 3'-phosphoadenylyl sulfate and estrone, whereas its two products are adenosine 3',5'-bisphosphate and estrone 3-sulfate. The enzyme also catalyzes the same reaction for estradiol, with estradiol sulfate as the product.
Numerical partial differential equations Spectral method Numerical_partial_differential_equations > Overview of methods > Spectral method Spectral methods are techniques used in applied mathematics and scientific computing to numerically solve certain differential equations, often involving the use of the fast Fourier transform. The idea is to write the solution of the differential equation as a sum of certain "basis functions" (for example, as a Fourier series, which is a sum of sinusoids) and then to choose the coefficients in the sum that best satisfy the differential equation. Spectral methods and finite element methods are closely related and built on the same ideas; the main difference between them is that spectral methods use basis functions that are nonzero over the whole domain, while finite element methods use basis functions that are nonzero only on small subdomains.
Artificial consciousness Ethics Artificial_consciousness > Philosophical views > Ethics If it were suspected that a particular machine was conscious, its rights would be an ethical issue that would need to be assessed (e.g. what rights it would have under law). For example, a conscious computer that was owned and used as a tool or central computer of a building of larger machine is a particular ambiguity. Should laws be made for such a case? Consciousness would also require a legal definition in this particular case.
Group intelligence Dimensions Group_intelligence > Dimensions Howard Bloom has discussed mass behavior – collective behavior from the level of quarks to the level of bacterial, plant, animal, and human societies. He stresses the biological adaptations that have turned most of this earth's living beings into components of what he calls "a learning machine". In 1986 Bloom combined the concepts of apoptosis, parallel distributed processing, group selection, and the superorganism to produce a theory of how collective intelligence works. Later he showed how the collective intelligences of competing bacterial colonies and human societies can be explained in terms of computer-generated "complex adaptive systems" and the "genetic algorithms", concepts pioneered by John Holland.Bloom traced the evolution of collective intelligence to our bacterial ancestors 1 billion years ago and demonstrated how a multi-species intelligence has worked since the beginning of life.
Vitamin A Immune functions Vitamin_A > Metabolic functions > Immune functions Vitamin A deficiency (VAD) has been linked to compromised resistance to infectious diseases. In countries where early childhood VAD is common, vitamin A supplementation public health programs initiated in the 1980s were shown to reduce the incidence of diarrhea and measles, and all-cause mortality. VAD also increases the risk of immune system over-reaction, leading to chronic inflammation in the intestinal system, stronger allergic reactions and autoimmune diseases.Lymphocytes and monocytes are types of white blood cells of the immune system. Lymphocytes include natural killer cells, which function in innate immunity, T cells for adaptive cellular immunity and B cells for antibody-driven adaptive humoral immunity.
Tropical medicine HIV Tropical_medicine > Challenges > HIV Tuberculosis is thought to cause a more rapid disease progression. Tuberculosis is prevalent in tropical and under-developed countries, only making HIV more devastating. Without the expensive and high-tech medical equipment of developed, western countries, physicians in the tropics are left with few options. If they are able to catch an HIV-related bacterial or mycobacterial disease they can diagnose and manage the disease with basic drugs and standard treatment protocol. Many under-developed countries do not have a care strategy, and of those that do, they aren't as effective as they need to be to stop the spread of HIV.
Multiple myeloma Treatment Multiple_myeloma > Treatment Commonly, the efficacy of each drug diminishes over time, as the cancer develops drug resistance mechanisms, such as by clonal evolution or genetic mutations. In part for this reason, multiple myeloma has not historically been treated when in its "smoldering" stage, since the drug(s) utilized may then be of diminished efficacy if the disease progresses to a symptomatic stage. Thus, the standard of care was "watchful waiting" while the disease smoldered.
Square function In real numbers Square_function > In real numbers The squaring operation defines a real function called the square function or the squaring function. Its domain is the whole real line, and its image is the set of nonnegative real numbers. The square function preserves the order of positive numbers: larger numbers have larger squares.
Evolutionary argument against naturalism Plantinga's 1993 formulation of the argument Evolutionary_argument_against_naturalism > Plantinga's 1993 formulation of the argument This will get his body parts in the right place so far as survival is concerned, without involving much by way of true belief. ... Or perhaps he thinks the tiger is a large, friendly, cuddly pussycat and wants to pet it; but he also believes that the best way to pet it is to run away from it. ... Clearly there are any number of belief-cum-desire systems that equally fit a given bit of behaviour.
Accidental symmetry In Quantum Mechanics Accidental_symmetry > In Quantum Mechanics This matrix has a P4 permutation symmetry, which in this basis is much easier to see, and could constitute a 'hidden' symmetry. In this case, there are no degeneracies in the eigenspectrum. The technical reason for this is that each eigenstate transforms with respect to a different irreducible representation of P4. If one encountered a case where some group of eigenstates correspond to the same irreducible representation of the 'hidden' symmetry group, a degeneracy would be observed. Although for this simple 4x4 matrix the symmetry could have been guessed (it was after all, always there to begin with), if the matrix was larger, it would have been more difficult to spot.
Power system automation Summary Power_system_automation Power-system automation includes processes associated with generation and delivery of power. Monitoring and control of power delivery systems in the substation and on the pole reduce the occurrence of outages and shorten the duration of outages that do occur. The IEDs, communications protocols, and communications methods, work together as a system to perform power-system automation.
Android rooting Summary Android_rooting Thus, it is primarily the third aspect of iOS jailbreaking (giving users administrative privileges) that most directly correlates to Android rooting. Rooting is distinct from SIM unlocking and bootloader unlocking. The former allows removing the SIM card lock on a phone, while the latter allows rewriting the phone's boot partition (for example, to install or replace the operating system).
System Identification Forward model System_Identification > Forward model A common understanding in Artificial Intelligence is that the controller has to generate the next move for a robot. For example, the robot starts in the maze and then the robot decides to move forward. Model predictive control determines the next action indirectly. The term “model” is referencing to a forward model which doesn't provide the correct action but simulates a scenario.
RNR5 Summary RNR5 RNA, ribosomal 5, also known as RNR5, is a human gene. Genes for ribosomal RNA are clustered on the short arms of chromosomes 13, 14, 15, 20, 21. The gene for RNR5 exists in multiple copies on chromosome 22. Each gene cluster contains 30–40 copies and encodes a 45S RNA product that is then cleaved to form 18S, 5.8S and 28S rRNA subunits. In general, genes for RNA remain poorly annotated in most large public databases.
Absolute Temperature Relationship to ideal gas law Thermodynamic_temperature > Relationship to ideal gas law Strictly speaking, the temperature of a system is well-defined only if it is at thermal equilibrium. From a microscopic viewpoint, a material is at thermal equilibrium if the quantity of heat between its individual particles cancel out. There are many possible scales of temperature, derived from a variety of observations of physical phenomena.
Cartesian power Cartesian product of functions Cartesian_power > Other forms > Cartesian product of functions If f is a function from X to A and g is a function from Y to B, then their Cartesian product f × g is a function from X × Y to A × B with ( f × g ) ( x , y ) = ( f ( x ) , g ( y ) ) . {\displaystyle (f\times g)(x,y)=(f(x),g(y)).} This can be extended to tuples and infinite collections of functions. This is different from the standard Cartesian product of functions considered as sets.
Neutrophil extracellular traps NET-associated host damage Neutrophil_extracellular_traps > NET-associated host damage NETs have also been found in cancer patients. Preclinical research suggests that NETs are jointly responsible for cancer-related pathologies like thrombosis, organ failure and metastasis formation.NETs have been shown to contribute to the pathogenesis of HIV/SIV. NETs are capable of capturing HIV virions and destroying them.
Alkenyl group Oxidation Unsaturated_(hydrocarbon) > Reactions > Addition reactions > Oxidation Reactions of the excited sensitizer can involve electron or hydrogen transfer, usually with a reducing substrate (Type I reaction) or interaction with oxygen (Type II reaction). These various alternative processes and reactions can be controlled by choice of specific reaction conditions, leading to a wide range of products. A common example is the -cycloaddition of singlet oxygen with a diene such as cyclopentadiene to yield an endoperoxide: Another example is the Schenck ene reaction, in which singlet oxygen reacts with an allylic structure to give a transposed allyl peroxide:
Writing table Summary Writing_table A writing table (French bureau plat) has a series of drawers directly under the surface of the table, to contain writing implements, so that it may serve as a desk. Antique versions have the usual divisions for the inkwell, the blotter and the sand or powder tray in one of the drawers, and a surface covered with leather or some other material less hostile to the quill or the fountain pen than simple hard wood. In form, a writing table is a pedestal desk without the pedestals, having legs instead to hold it up. This is why such tables are sometimes called leg desks.
Fast-and-frugal trees Construction Fast-and-frugal_trees > Basic Organization > Construction A characteristic property of fast-and-frugal trees is that, for each question, there is at least one possible answer that leads to an exit. In the literature on fast-and-frugal trees, many different algorithms have been proposed for (1) ordering cues and (2) deciding which possible answer to a question about a cue leads immediately to an exit. A fast-and-frugal tree is fully defined if both the following conditions are met. Often, in order to keep construction simple and intuitive, the algorithms use (1) simple measures of cue "goodness" (e.g., correlation between cue and category, considering each cue independently of the other cues) and (2) make simple choices about exits (e.g., decide on each exit independently of the other exits), but more complex algorithms have been proposed as well.
Wireless telecommunications Electromagnetic induction Wireless_telecommunication > Modes > Electromagnetic induction Electromagnetic induction only allows short-range communication and power transmission. It has been used in biomedical situations such as pacemakers, as well as for short-range RFID tags.
Adrian Bejan Career Adrian_Bejan > Career From 1976 to 1978 Bejan was a Miller research fellow in at the University of California Berkeley working with Chang-Lin Tien. In 1978 he moved to Colorado and joined the faculty of the Department of Mechanical Engineering at the University of Colorado in Boulder. In 1982 Bejan published his first book, Entropy Generation Through Heat and Fluid Flow. The book is aimed at practical applications of the second law of thermodynamics, and presented his ideas on irreversibility, availability and exergy analysis in a form for engineers.
COVID-19 pandemic Transmission COVID-19_pandemic > Disease > Transmission The disease is mainly transmitted via the respiratory route when people inhale droplets and small airborne particles (that form an aerosol) that infected people exhale as they breathe, talk, cough, sneeze, or sing. Infected people are more likely to transmit COVID-19 when they are physically close to other non-infected individuals. However, infection can occur over longer distances, particularly indoors.
Mechanic strength Stress parameters for resistance Mechanical_strength > Definition > Stress parameters for resistance The tensile strength can be quoted as either true stress or engineering stress, but engineering stress is the most commonly used. Fatigue strength is a more complex measure of the strength of a material that considers several loading episodes in the service period of an object, and is usually more difficult to assess than the static strength measures. Fatigue strength is quoted here as a simple range ( Δ σ = σ m a x − σ m i n {\displaystyle \Delta \sigma =\sigma _{\mathrm {max} }-\sigma _{\mathrm {min} }} ).
Crossfade (audio engineering) Logarithmic Fade_(audio_engineering) > Fade > Shapes > Logarithmic The logarithmic fade sounds consistent and smooth since the perceived volume is increased over the whole duration of the fade. This makes this curve very handy for fading standard pieces of music. It is best used on a long fade-out since the fade has a perceived linear nature.
Transistor Bipolar junction transistor (BJT) Silicon_transistor > Types > Bipolar junction transistor (BJT) BJTs have three terminals, corresponding to the three layers of semiconductor—an emitter, a base, and a collector. They are useful in amplifiers because the currents at the emitter and collector are controllable by a relatively small base current. In an n–p–n transistor operating in the active region, the emitter-base junction is forward biased (electrons and holes recombine at the junction), and the base-collector junction is reverse biased (electrons and holes are formed at, and move away from the junction), and electrons are injected into the base region.
Classical analysis Differential equations Hard_analysis > Main branches > Differential equations This is illustrated in classical mechanics, where the motion of a body is described by its position and velocity as the time value varies. Newton's laws allow one (given the position, velocity, acceleration and various forces acting on the body) to express these variables dynamically as a differential equation for the unknown position of the body as a function of time. In some cases, this differential equation (called an equation of motion) may be solved explicitly.
Mechanical–electrical analogies Through and across analogies Mechanical–electrical_analogies > Classes of analogy > Through and across analogies Through and across analogies, also called the Trent analogy, classify the two variables making up the power conjugate pair as an across variable and a through variable. The across variable is a variable that appears across the two terminals of an element. The across variable is measured relative to the element terminals. The through variable is a variable that passes through, or acts through an element, that is, it has the same value at both terminals of the element.
Positive and negative predictive values Different target conditions Negative_predictive_value > Problems > Different target conditions PPV is used to indicate the probability that in case of a positive test, that the patient really has the specified disease. However, there may be more than one cause for a disease and any single potential cause may not always result in the overt disease seen in a patient. There is potential to mix up related target conditions of PPV and NPV, such as interpreting the PPV or NPV of a test as having a disease, when that PPV or NPV value actually refers only to a predisposition of having that disease.An example is the microbiological throat swab used in patients with a sore throat. Usually publications stating PPV of a throat swab are reporting on the probability that this bacterium is present in the throat, rather than that the patient is ill from the bacteria found.
Chronic viral hepatitis Autoimmune Chronic_viral_hepatitis > Causes > Autoimmune Other autoantibodies that are less common but more specific to autoimmune hepatitis are the antibodies against liver kidney microsome 1 (LKM1) and soluble liver antigen (SLA). Autoimmune hepatitis can also be triggered by drugs (such as nitrofurantoin, hydralazine, and methyldopa), after liver transplant, or by viruses (such as hepatitis A, Epstein-Barr virus, or measles).Autoimmune hepatitis can present anywhere within the spectrum from asymptomatic to acute or chronic hepatitis to fulminant liver failure. Patients are asymptomatic 25–34% of the time, and the diagnosis is suspected on the basis of abnormal liver function tests.
European Laboratory for Non-Linear Spectroscopy European Laserlab consortium European_Laboratory_for_Non-Linear_Spectroscopy > European Laserlab consortium As a laser facility, LENS is part of the Laserlab-Europe consortium since its foundation, providing access to its labs within the Transnational Access To Research Infrastructures Programme of the European Commission. Main research interests are represented by five Joint Research Activities Archived 2010-03-23 at the Wayback Machine, two of which involve LENS: ALADIN and OPTBIO .
Story generator Overview Story_generator > Overview Plot generators were described as early as the late 1920s, with Plotto; a new method of plot suggestion for writers of creative fiction, by William Wallace Cook, appearing in 1928. Plotto is a non-random plot generator; the reader makes all the decisions within the framework set out by the book.In an article originally published in 1935 and reprinted in 2002, Robert J. Hogan described a book-based device called the Plot Genie which consisted of three lists of 180 items each: murder victims in the first list, crime locations in the second list, and important clues in the third list. The item to use from each list was chosen by spinning a dial with 180 numbers on it. Hogan also mentions other similar devices such as The 36 Dramatic Situations and Plotto (see above).The earliest computerized story generator was TALE-SPIN, an artificial intelligence program developed in the 1970s.
Eight Trigrams Summary Eight_Trigrams The trigrams have correspondences in astronomy, divination, meditation, astrology, geography, geomancy (fengshui), anatomy, decorative arts, the family, martial arts (particularly taijiquan and baguazhang), Chinese medicine and elsewhere.The bagua can appear singly or in combination, and are commonly encountered in two different arrangements: the Primordial (先天八卦), "Earlier Heaven", or "Fu Xi" bagua (伏羲八卦) and the Manifested (後天八卦), "Later Heaven", or "King Wen" bagua. In the ancient Chinese classic, I Ching (Pinyin: Yi Jing), two trigrams are stacked together to create a six-line figure known as a hexagram. There are 64 possible permutations.
Denotational semantics Meanings of recursive programs Fully_abstract > Historical development > Meanings of recursive programs In the limit we get a total function from N {\displaystyle \mathbb {N} } to N {\displaystyle \mathbb {N} } defined everywhere in its domain. Formally we model each approximation as a partial function N ⇀ N {\displaystyle \mathbb {N} \rightharpoonup \mathbb {N} } . Our approximation is then repeatedly applying a function implementing "make a more defined partial factorial function", i.e. F: ( N ⇀ N ) → ( N ⇀ N ) {\displaystyle F:(\mathbb {N} \rightharpoonup \mathbb {N} )\to (\mathbb {N} \rightharpoonup \mathbb {N} )} , starting with the empty function (empty set).
Logical reasoning Abductive Mathematical_reasoning > Non-deductive reasoning > Abductive The hypotheses are then tested and compared to discover which one provides the best explanation. This pertains particularly to cases of causal reasoning that try to discover the relation between causes and effects.
Contextual cueing effect Early studies Contextual_cueing_effect > Theory development > Early studies The standard contextual-cueing task first developed by Chun and Jiang in 1998 pioneered research in the development of this area of study. The results showed how, in global contexts, implicit learning and memory of visual context can navigate spatial attention towards task-relevant aspects of a scene.
Graphical method Biological sciences Graphical_method > Biological sciences Cladogram Punnett square Systems Biology Graphical Notation
Schmidt–Kalman filter Summary Schmidt–Kalman_filter The Schmidt–Kalman Filter is a modification of the Kalman filter for reducing the dimensionality of the state estimate, while still considering the effects of the additional state in the calculation of the covariance matrix and the Kalman gains. A common application is to account for the effects of nuisance parameters such as sensor biases without increasing the dimensionality of the state estimate. This ensures that the covariance matrix will accurately represent the distribution of the errors.
Deepfake Summary Deepfake The main machine learning methods used to create deepfakes are based on deep learning and involve training generative neural network architectures, such as autoencoders, or generative adversarial networks (GANs). In turn the field of image forensics develops techniques to detect manipulated images.Deepfakes have garnered widespread attention for their potential use in creating child sexual abuse material, celebrity pornographic videos, revenge porn, fake news, hoaxes, bullying, and financial fraud. The spreading of disinformation and hate speech through deepfakes has a potential to undermine core functions and norms of democratic systems by interfering with people's ability to participate in decisions that affect them, determine collective agendas and express political will through informed decision-making. This has elicited responses from both industry and government to detect and limit their use.From traditional entertainment to gaming, deepfake technology has evolved to be increasingly convincing and available to the public, allowing the disruption of the entertainment and media industries.
Free fall sensor Biology Free_fall_sensor > Applications > Biology Accelerometers are also increasingly used in the biological sciences. High frequency recordings of bi-axial or tri-axial acceleration allows the discrimination of behavioral patterns while animals are out of sight. Furthermore, recordings of acceleration allow researchers to quantify the rate at which an animal is expending energy in the wild, by either determination of limb-stroke frequency or measures such as overall dynamic body acceleration Such approaches have mostly been adopted by marine scientists due to an inability to study animals in the wild using visual observations, however an increasing number of terrestrial biologists are adopting similar approaches.
Examples of vector spaces Generalized coordinate space Examples_of_vector_spaces > Function spaces > Generalized coordinate space Likewise, if X is the set of natural numbers, N, then this space is just F∞. A canonical basis for (FX)0 is the set of functions {δx \| x ∈ X} defined by δ x ( y ) = { 1 x = y 0 x ≠ y {\displaystyle \delta _{x}(y)={\begin{cases}1\quad x=y\\0\quad x\neq y\end{cases}}} The dimension of (FX)0 is therefore equal to the cardinality of X. In this manner we can construct a vector space of any dimension over any field. Furthermore, every vector space is isomorphic to one of this form.
Reflection high-energy electron diffraction RHEED patterns of real surfaces Reflection_high_energy_electron_diffraction > RHEED patterns of real surfaces Diffraction conditions are fulfilled over the entire intersection of the rods with the sphere, yielding elongated points or ‘streaks’ along the vertical axis of the RHEED pattern. In real cases, streaky RHEED patterns indicate a flat sample surface while the broadening of the streaks indicate small area of coherence on the surface. Surface features and polycrystalline surfaces add complexity or change RHEED patterns from those from perfectly flat surfaces. Growing films, nucleating particles, crystal twinning, grains of varying size and adsorbed species add complicated diffraction conditions to those of a perfect surface. Superimposed patterns of the substrate and heterogeneous materials, complex interference patterns and degradation of the resolution are characteristic of complex surfaces or those partially covered with heterogeneous materials.
Frequency histogram Examples Frequency_histogram > Examples Census Bureau found that there were 124 million people who work outside of their homes. Using their data on the time occupied by travel to work, the table below shows the absolute number of people who responded with travel times "at least 30 but less than 35 minutes" is higher than the numbers for the categories above and below it. This is likely due to people rounding their reported journey time.
Stroke recovery Post-stroke depression Stroke_rehabilitation > Post-stroke depression Traditionally, tricyclic antidepressants (TCAs), such as nortriptyline, have been used in the treatment of post-stroke depression. More recently, the selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine and citalopram, have become the pharmacologic therapy of choice due to the lower incidence of side effects. Also, psychologic treatment such as cognitive behavioral therapy, group therapy, and family therapy are reported to be useful adjuncts to treatment.
Database replication Summary Database_replication Replication in computing involves sharing information so as to ensure consistency between redundant resources, such as software or hardware components, to improve reliability, fault-tolerance, or accessibility.
Critical line (mathematics) Littlewood's theorem Critical_line_theorem > Consequences > Excluded middle > Littlewood's theorem This concerns the sign of the error in the prime number theorem. It has been computed that π(x) < li(x) for all x ≤ 1025 (see this table), and no value of x is known for which π(x) > li(x). In 1914 Littlewood proved that there are arbitrarily large values of x for which π ( x ) > li ⁡ ( x ) + 1 3 x log ⁡ x log ⁡ log ⁡ log ⁡ x , {\displaystyle \pi (x)>\operatorname {li} (x)+{\frac {1}{3}}{\frac {\sqrt {x}}{\log x}}\log \log \log x,} and that there are also arbitrarily large values of x for which π ( x ) < li ⁡ ( x ) − 1 3 x log ⁡ x log ⁡ log ⁡ log ⁡ x . {\displaystyle \pi (x)<\operatorname {li} (x)-{\frac {1}{3}}{\frac {\sqrt {x}}{\log x}}\log \log \log x.}
Circle of latitude Summary Circle_of_latitude The Equator is at 0°, and the North Pole and South Pole are at 90° north and 90° south, respectively. The Equator is the longest circle of latitude and is the only circle of latitude which also is a great circle. As such, it is perpendicular to all meridians.
Electric resistance welding Summary Resistance_seam_welding Electric resistance welding (ERW) is a welding process where metal parts in contact are permanently joined by heating them with an electric current, melting the metal at the joint. Electric resistance welding is widely used, for example, in manufacture of steel pipe and in assembly of bodies for automobiles. The electric current can be supplied to electrodes that also apply clamping pressure, or may be induced by an external magnetic field. The electric resistance welding process can be further classified by the geometry of the weld and the method of applying pressure to the joint: spot welding, seam welding, flash welding, projection welding, for example.
Mathematical discipline Computational mathematics Mathematical_research > Areas of mathematics > Computational mathematics Computational mathematics is the study of mathematical problems that are typically too large for human, numerical capacity. Numerical analysis studies methods for problems in analysis using functional analysis and approximation theory; numerical analysis broadly includes the study of approximation and discretization with special focus on rounding errors. Numerical analysis and, more broadly, scientific computing also study non-analytic topics of mathematical science, especially algorithmic-matrix-and-graph theory. Other areas of computational mathematics include computer algebra and symbolic computation.
Audio feedback Devices Acoustic_feedback > Deliberate uses > Devices The principle of feedback is used in many guitar sustain devices. Examples include handheld devices like the EBow, built-in guitar pickups that increase the instrument's sonic sustain, string drivers mounted on a stand such as the Guitar Resonator, and sonic transducers mounted on the head of a guitar. Intended closed-circuit feedback can also be created by an effects unit, such as a delay pedal or effect fed back into a mixing console.
Hypertensive nephropathy Causes Hypertensive_nephropathy > Causes "Hypertensive" refers to high blood pressure and "nephropathy" means damage to the kidney; hence this condition is where chronic high blood pressure causes damages to kidney tissue; this includes the small blood vessels, glomeruli, kidney tubules and interstitial tissues. The tissue hardens and thickens which is known as nephrosclerosis. The narrowing of the blood vessels means less blood is going to the tissue and so less oxygen is reaching the tissue resulting in tissue death (ischemia).Risk factors for HN include poorly controlled, moderate-to-severe hypertension, older age, other kidney disorders, and Afro-Caribbean background, whose exact cause is unclear, as it may be due to either genetic susceptibility or poor health management among people of Afro-Caribbean descent.
Filter feeder Bivalves Filter_feeder > Bivalves Bivalve shellfish recycle nutrients that enter waterways from human and agricultural sources. Nutrient bioextraction is "an environmental management strategy by which nutrients are removed from an aquatic ecosystem through the harvest of enhanced biological production, including the aquaculture of suspension-feeding shellfish or algae". Nutrient removal by shellfish, which are then harvested from the system, has the potential to help address environmental issues including excess inputs of nutrients (eutrophication), low dissolved oxygen, reduced light availability and impacts on eelgrass, harmful algal blooms, and increases in incidence of paralytic shellfish poisoning (PSP).
Cytoplasmic hypereosinophilia Morphological patterns Tissue_death > Classification > Morphological patterns It is characteristic of ischemia of lower limb and the gastrointestinal tracts. If superimposed infection of dead tissues occurs, then liquefactive necrosis ensues (wet gangrene). Caseous necrosis can be considered a combination of coagulative and liquefactive necrosis, typically caused by mycobacteria (e.g. tuberculosis), fungi and some foreign substances.
Time limit Summary Time_limit A time limit or deadline is a narrow field of time, or a particular point in time, by which an objective or task must be accomplished. Once that time has passed, the item may be considered overdue (e.g., for work projects or school assignments). In the case of work assignments or projects that are not completed by the deadline, this may adversely affect the employee's performance rating. In the case of school assignments, essays or reports submitted after the deadline, marks or grades may be deducted from the student's assessment.
Economic cycle Classification by periods Business_cycles > History > Classification by periods A range of periods rather than one fixed period is needed to capture business cycle fluctuations, which may be done by using a random or irregular source as in an econometric or statistical framework. The Kuznets infrastructural investment cycle of 15 to 25 years (after Simon Kuznets – also called "building cycle") The Kondratiev wave or long technological cycle of 45 to 60 years (after the Soviet economist Nikolai Kondratiev)Some say interest in the different typologies of cycles has waned since the development of modern macroeconomics, which gives little support to the idea of regular periodic cycles. Further econometric studies such as the two works in 2003 and 2007 cited above demonstrate a clear tendency for cyclical components in macroeconomic times to behave in a stochastic rather than deterministic way.
Hybrid kernel Description Hybrid_kernel > Examples > XNU kernel > Description Like some other modern kernels, XNU is a hybrid, containing features of both monolithic and microkernels, attempting to make the best use of both technologies, such as the message passing capability of microkernels enabling greater modularity and larger portions of the OS to benefit from protected memory, as well as retaining the speed of monolithic kernels for certain critical tasks.
Computer-automated design Dealing with practical objectives Computer-automated_design > Dealing with practical objectives In practice, the objective value may be noisy or even non-numerical, and hence its gradient information may be unreliable or unavailable. This is particularly true when the problem is multi-objective. At present, many designs and refinements are mainly made through a manual trial-and-error process with the help of a CAD simulation package. Usually, such a posteriori learning or adjustments need to be repeated many times until a ‘satisfactory’ or ‘optimal’ design emerges.
Lorenz number Derivation Wiedemann–Franz_law > Derivation Since the electric field and the current density are vectors Ohm's law is expressed here in bold face. The conductivity can in general be expressed as a tensor of the second rank (3×3 matrix).
Probabilistic metric space Example Probabilistic_metric_space > Probability metric of random variables > Example For example if both probability distribution functions of random variables X and Y are normal distributions (N) having the same standard deviation σ {\displaystyle \sigma } , integrating D ( X , Y ) {\displaystyle D\left(X,Y\right)} yields: where and erfc ⁡ ( x ) {\displaystyle \operatorname {erfc} (x)} is the complementary error function. In this case:
Urinary infection Classification Urinary_infection > Diagnosis > Classification If a urinary tract infection involves the upper tract, and the person has diabetes mellitus, is pregnant, is male, or immunocompromised, it is considered complicated. Otherwise if a woman is healthy and premenopausal it is considered uncomplicated. In children when a urinary tract infection is associated with a fever, it is deemed to be an upper urinary tract infection.
Symmetric matrices Symmetrizable matrix Real_symmetric_matrix > Symmetrizable matrix An n × n {\displaystyle n\times n} matrix A {\displaystyle A} is said to be symmetrizable if there exists an invertible diagonal matrix D {\displaystyle D} and symmetric matrix S {\displaystyle S} such that A = D S . {\displaystyle A=DS.} The transpose of a symmetrizable matrix is symmetrizable, since A T = ( D S ) T = S D = D − 1 ( D S D ) {\displaystyle A^{\mathrm {T} }=(DS)^{\mathrm {T} }=SD=D^{-1}(DSD)} and D S D {\displaystyle DSD} is symmetric.
Open Platform Management Architecture Summary Open_Platform_Management_Architecture Open Platform Management Architecture (OPMA) is an open, royalty free standard for connecting a modular, platform hardware management subsystem (an "mCard") to a computer motherboard. Platform hardware management generally refers to the remote monitoring of platform hardware variables such as fan speed, voltages, CPU and enclosure temperatures along with a wide range of other sensors. It also implies the ability to remotely control the power state of the platform and to reset the system back into an operational state should it "hang". A significant advantage of OPMA over previous generation management subsystem attachment methods is that OPMA does not consume a PCI socket.
Static structure Solids Static_structure > Applications > Solids Statics is used in the analysis of structures, for instance in architectural and structural engineering. Strength of materials is a related field of mechanics that relies heavily on the application of static equilibrium. A key concept is the center of gravity of a body at rest: it represents an imaginary point at which all the mass of a body resides. The position of the point relative to the foundations on which a body lies determines its stability in response to external forces.
Zorns lemma History Zorns_lemma > History The Hausdorff maximal principle is an early statement similar to Zorn's lemma. Kazimierz Kuratowski proved in 1922 a version of the lemma close to its modern formulation (it applies to sets ordered by inclusion and closed under unions of well-ordered chains). Essentially the same formulation (weakened by using arbitrary chains, not just well-ordered) was independently given by Max Zorn in 1935, who proposed it as a new axiom of set theory replacing the well-ordering theorem, exhibited some of its applications in algebra, and promised to show its equivalence with the axiom of choice in another paper, which never appeared. The name "Zorn's lemma" appears to be due to John Tukey, who used it in his book Convergence and Uniformity in Topology in 1940. Bourbaki's Théorie des Ensembles of 1939 refers to a similar maximal principle as "le théorème de Zorn". The name "Kuratowski–Zorn lemma" prevails in Poland and Russia.
Markov constant History and motivation Markov_constant > History and motivation {\displaystyle \left\|\alpha -{\frac {p}{q}}\right\|<{\frac {1}{{\sqrt {5}}q^{2}}}.} The above result is best possible since the golden ratio ϕ {\displaystyle \phi } is irrational but if we replace √5 by any larger number in the above expression then we will only be able to find finitely many rational numbers that satisfy the inequality for α = ϕ {\displaystyle \alpha =\phi } . Furthermore, he showed that among the irrational numbers, the least readily approximable numbers are those of the form a ϕ + b c ϕ + d {\displaystyle {\frac {a\phi +b}{c\phi +d}}} where ϕ {\displaystyle \phi } is the golden ratio, a , b , c , d ∈ Z {\displaystyle a,b,c,d\in \mathbb {Z} } and a d − b c = ± 1 {\displaystyle ad-bc=\pm 1} .
Radical SAM Nomenclature Radical_SAM > Nomenclature Lastly, the class of the enzyme will be described in the other half of the name which will end in suffix -ase. The class of an enzyme will describe what the enzyme is doing or changing on the substrate. For example, a ligase combines two molecules to form a new bond.
Gerard 't Hooft Quantum gravity and black holes Gerard_'t_Hooft > Research > Quantum gravity and black holes When Veltman and 't Hooft moved to CERN after 't Hooft obtained his PhD, Veltman's attention was drawn to the possibility of using their dimensional regularization techniques to the problem of quantizing gravity. Although it was known that perturbative quantum gravity was not completely renormalizible, they felt important lessons were to be learned by studying the formal renormalization of the theory order by order. This work would be continued by Stanley Deser and another PhD student of Veltman, Peter van Nieuwenhuizen, who later found patterns in the renormalization counter terms, which led to the discovery of supergravity.In the 1980s, 't Hooft's attention was drawn to the subject of gravity in 3 spacetime dimensions.
Radar graph Data set size Radar_graph > Limitations > Data set size Radar charts are helpful for small-to-moderate-sized multivariate data sets. Their primary weakness is that their effectiveness is limited to data sets with less than a few hundred points. After that, they tend to be overwhelming.Further, when using radar charts with multiple dimensions or samples, the radar chart may become cluttered and harder to interpret as the number of samples grows.
Pantoprazole Pharmacology Pantoprazole > Pharmacology The mechanism of action of pantoprazole is to inhibit the final step in gastric acid production. In the gastric parietal cell of the stomach, pantoprazole covalently binds to the H+/K+ ATP pump to inhibit gastric acid and basal acid secretion. The covalent binding prevents acid secretion for up to 24 hours and longer.Pantoprazole is metabolized in the liver by the cytochrome P450 system. Metabolism mainly consists of demethylation by CYP2C19 followed by sulfation.
Optical lattice Quantum information Optical_lattice > Uses > Quantum information They are also promising candidates for quantum information processing.
Bohr-Sommerfeld model Issues Bohr–Sommerfeld_model > Issues The current picture of the hydrogen atom is based on the atomic orbitals of wave mechanics, which Erwin Schrödinger developed in 1926. However, this is not to say that the Bohr–Sommerfeld model was without its successes. Calculations based on the Bohr–Sommerfeld model were able to accurately explain a number of more complex atomic spectral effects.
Hidden variable theories Declaration of completeness of quantum mechanics, and the Bohr–Einstein debates Hidden-variables_theory > Declaration of completeness of quantum mechanics, and the Bohr–Einstein debates Also at the Fifth Solvay Congress, Max Born and Werner Heisenberg made a presentation summarizing the recent tremendous theoretical development of quantum mechanics. At the conclusion of the presentation, they declared: hile we consider ... a quantum mechanical treatment of the electromagnetic field ... as not yet finished, we consider quantum mechanics to be a closed theory, whose fundamental physical and mathematical assumptions are no longer susceptible of any modification.... On the question of the 'validity of the law of causality' we have this opinion: as long as one takes into account only experiments that lie in the domain of our currently acquired physical and quantum mechanical experience, the assumption of indeterminism in principle, here taken as fundamental, agrees with experience. Although there is no record of Einstein responding to Born and Heisenberg during the technical sessions of the Fifth Solvay Congress, he did challenge the completeness of quantum mechanics at various times. In his tribute article for Born's retirement he discussed the quantum representation of a macroscopic ball bouncing elastically between rigid barriers.
Quantum Interactive Protocol Summary Quantum_Interactive_Polynomial_time By restricting the number of messages used in the protocol to at most k, we get the complexity class QIP(k). QIP and QIP(k) were introduced by John Watrous, who along with Kitaev proved in a later paper that QIP = QIP(3), which shows that 3 messages are sufficient to simulate a polynomial-round quantum interactive protocol. Since QIP(3) is already QIP, this leaves 4 possibly different classes: QIP(0), which is BQP, QIP(1), which is QMA, QIP(2) and QIP.
Neuropsychopharmacology Neural circuits Neuropsychopharmacology > Neural circuits This may better explain the difference between the pharmacology of serotonergic neurotransmission (even if promoted by drugs such as SSRIs) and that of classical psychedelics. Newer findings, however, indicate that binding to the 5HT2A-mGlu2 heterodimer is also necessary for classical psychedelic activity. This, too, may be relevant to the pharmacological differences between the two.
Equine gastric ulcer syndrome Pathophysiology Equine_gastric_ulcer_syndrome > Pathophysiology The duodenum is protected by its motility which removes HCl, glands in its surface that produce mucins, and products from the pancreas, including bicarbonate, to help neutralize the acidity. Most duodenal ulcers occur in foals, and there appears to be an association between duodenal ulcers and enteritis in these animals. Duodenal ulcers may result in inflammation of the duodenum so profound it blocks gastric emptying, which can cause severe gastric ulcers and occasionally esophageal ulcers. Often this must be treated with a gastrojejunostomy, which is a risky procedure.
Stack canary Exploiting stack buffer overflows Stack_based_buffer_overflow > Exploiting stack buffer overflows In an actual stack buffer overflow exploit the string of "A"'s would instead be shellcode suitable to the platform and desired function. If this program had special privileges (e.g. the SUID bit set to run as the superuser), then the attacker could use this vulnerability to gain superuser privileges on the affected machine.The attacker can also modify internal variable values to exploit some bugs. With this example:
Modularity (biology) Summary Modularity_(biology) Modularity refers to the ability of a system to organize discrete, individual units that can overall increase the efficiency of network activity and, in a biological sense, facilitates selective forces upon the network. Modularity is observed in all model systems, and can be studied at nearly every scale of biological organization, from molecular interactions all the way up to the whole organism.
Instruction set architectures Complex instructions Variable-length_instruction_set > Instructions > Complex instructions Processors may include "complex" instructions in their instruction set. A single "complex" instruction does something that may take many instructions on other computers. Such instructions are typified by instructions that take multiple steps, control multiple functional units, or otherwise appear on a larger scale than the bulk of simple instructions implemented by the given processor. Some examples of "complex" instructions include: transferring multiple registers to or from memory (especially the stack) at once moving large blocks of memory (e.g. string copy or DMA transfer) complicated integer and floating-point arithmetic (e.g. square root, or transcendental functions such as logarithm, sine, cosine, etc.) SIMD instructions, a single instruction performing an operation on many homogeneous values in parallel, possibly in dedicated SIMD registers performing an atomic test-and-set instruction or other read-modify-write atomic instruction instructions that perform ALU operations with an operand from memory rather than a registerComplex instructions are more common in CISC instruction sets than in RISC instruction sets, but RISC instruction sets may include them as well.
Biobank ethics Privacy for research participants Biobank_ethics > Privacy for research participants This is because the historical methods of protecting confidentiality and anonymity have become obsolete when radically more detailed databases became available. Another problem is that even small amounts of genetic data, such as a record of 100 single nucleotide polymorphisms, can uniquely identify anyone.There have been problems deciding what safeguards should be in place for storing medical research data. In response, some researchers have made efforts to describe what constitutes sufficient security and to recognize what seemingly anonymized information can be used to identify donors.
AC phase Number of phases Phase_(electricity) > Number of phases Two-phase systems have been replaced with three-phase systems. A two-phase supply with 90 degrees between phases can be derived from a three-phase system using a Scott-connected transformer.
Thyroid abnormalities Pathophysiology Thyroid_problems > Pathophysiology Most thyroid disease in the United States stems from a condition where the body's immune system attacks itself. In other instances, thyroid disease comes from the body trying to adapt to environmental conditions like iodine deficiency or to new physiologic conditions like pregnancy.
P (peptidyl) site Prokaryotic ribosomes P_(peptidyl)_site > Structure > Prokaryotic ribosomes The ribosomal subunits of prokaryotes and eukaryotes are quite similar.The unit of measurement used to describe the ribosomal subunits and the rRNA fragments is the Svedberg unit, a measure of the rate of sedimentation in centrifugation rather than size. This accounts for why fragment names do not add up: for example, bacterial 70S ribosomes are made of 50S and 30S subunits. Prokaryotes have 70S ribosomes, each consisting of a small (30S) and a large (50S) subunit.
Data Management Platform Data pipeline Data_Management_Platform > Data pipeline It first cleans the data by filtering out any junk or missing values. Then, it utilizes machine learning algorithms to find patterns across sets of users and organize them on a broad scale.
Group (mathematics) Examples and applications Group_(mathematics) > Examples and applications The blue loop is considered null-homotopic (and thus irrelevant), because it can be continuously shrunk to a point. The presence of the hole prevents the orange loop from being shrunk to a point. The fundamental group of the plane with a point deleted turns out to be infinite cyclic, generated by the orange loop (or any other loop winding once around the hole).
Business simulation History Business_simulation > History Air Force inventory management within its supply system. Greenlaw et al. state that business simulation exercises may be considered an outgrowth of earlier developments in three fields: military war gaming, operations research, and educational role-playing. According to Naylor, the use of games in business and economics goes back to 1956 when the American Management Association developed the first so-called management decision-making game, called the Top Management Decision Game.
Oppenheimer–Snyder model Reception and legacy Oppenheimer–Snyder_model > Reception and legacy Physicists were initially skeptical of the model, with Kip Thorne saying that the community saw the model as "truly strange" at the time. John Archibald Wheeler, a theoretical physicist who would go on to popularize the phrase "black hole" in the 1960s, was an opponent to the model in the 1950s.The model would later be described as forward thinking. After winning the Nobel Prize in Physics in 2020, Roger Penrose would credit the Oppenheimer–Snyder model as one of his inspirations for research.The Hindu wrote in 2023: The world of physics does indeed remember the paper. While Oppenheimer is remembered in history as the “father of the atomic bomb”, his greatest contribution as a physicist was on the physics of black holes. The work of Oppenheimer and Hartland Snyder helped transform black holes from figments of mathematics to real, physical possibilities – something to be found in the cosmos out there.
Lindlar's catalyst Summary Lindlar_palladium A Lindlar catalyst is a heterogeneous catalyst consisting of palladium deposited on calcium carbonate or barium sulfate then poisoned with various forms of lead or sulfur. It is used for the hydrogenation of alkynes to alkenes (i.e. without further reduction into alkanes). . It is named after its inventor Herbert Lindlar.

Subsets and Splits

No community queries yet

The top public SQL queries from the community will appear here once available.