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The halting problem Approximations Halting_problem > Computability theory > Approximations There are infrequently occurring new varieties of programs that come in arbitrarily large "blocks", and a constantly growing fraction of repeats. If the blocks of new varieties are fully included, the error rate is at least ϵ {\displaystyle \epsilon } , but between blocks the fraction of correctly categorized repeats can be arbitrarily high. In particular a "tally" heuristic that simply remembers the first N inputs and recognizes their equivalents allows reaching an arbitrarily low error rate infinitely often.
Chemical sensor Summary Distance_sensor Analog sensors such as potentiometers and force-sensing resistors are still widely used. Their applications include manufacturing and machinery, airplanes and aerospace, cars, medicine, robotics and many other aspects of our day-to-day life.
Graph energy Summary Graph_energy It is assumed that G is simple, that is, it does not contain loops or parallel edges. Let A be the adjacency matrix of G and let λ i {\displaystyle \lambda _{i}} , i = 1 , … , n {\displaystyle i=1,\ldots ,n} , be the eigenvalues of A. Then the energy of the graph is defined as: E ( G ) = ∑ i = 1 n \| λ i \| . {\displaystyle E(G)=\sum _{i=1}^{n}\|\lambda _{i}\|.}
Brittle fracture Strength Fracture > Strength If a ductile material reaches its ultimate tensile strength in a load-controlled situation, it will continue to deform, with no additional load application, until it ruptures. However, if the loading is displacement-controlled, the deformation of the material may relieve the load, preventing rupture. The statistics of fracture in random materials have very intriguing behavior, and was noted by the architects and engineers quite early.
Statistical potential Overview Statistical_potential > Overview Possible features to which a pseudo-energy can be assigned include: interatomic distances, torsion angles, solvent exposure, or hydrogen bond geometry.The classic application is, however, based on pairwise amino acid contacts or distances, thus producing statistical interatomic potentials. For pairwise amino acid contacts, a statistical potential is formulated as an interaction matrix that assigns a weight or energy value to each possible pair of standard amino acids. The energy of a particular structural model is then the combined energy of all pairwise contacts (defined as two amino acids within a certain distance of each other) in the structure. The energies are determined using statistics on amino acid contacts in a database of known protein structures (obtained from the PDB).
Glossary of computer science P Glossary_of_computer_science > P Subroutines may be defined within programs, or separately in libraries that can be used by many programs. In different programming languages, a subroutine may be called a routine, subprogram, function, method, or procedure.
Inner model Summary Inner_model In set theory, a branch of mathematical logic, an inner model for a theory T is a substructure of a model M of a set theory that is both a model for T and contains all the ordinals of M.
Metric system Base and derived unit structure Metric_system > Principles > Base and derived unit structure For example, in the modern metric system, length has the unit metre and time has the unit second, and speed has the derived unit metre per second. : 15 Density, or mass per unit volume, has the unit kilogram per cubic metre. : 434
Data diplomacy Data sensitivity and data security Data_diplomacy > Risks and limitations > Data sensitivity and data security One of the risks and impediments to data diplomacy is the issue of sensitive data and data security. Some data, such as pathogen sequence data and genetic sequence data are sensitive because they are located at the core of multiple global value production chains. The disclosure and sharing of such data can be subject to considerable political pressure. If data information causes leakage, it will lead to very serious consequences.
Young adult novel Pre-20th-century Young_adult_literature > History > Pre-20th-century It contains riddles, pictures, and 'pleasant and delightful relations of many rare and notable accidents and occurrences' which has suggested to some that it should be thought of as an early children's book. However, its title-page insists that it is "excellently accommodated to the fancies of old or young". A number of works by eighteenth and nineteenth-century authors, though not written specifically for young readers, have appealed to them.
Finite Element Analysis General form of the finite element method Finite_element > Discretization > General form of the finite element method In general, the finite element method is characterized by the following process. One chooses a grid for Ω {\displaystyle \Omega } . In the preceding treatment, the grid consisted of triangles, but one can also use squares or curvilinear polygons. Then, one chooses basis functions.
Machine learning in bioinformatics Workflow Machine_learning_in_bioinformatics > Machine learning approaches > Workflow Typically, a workflow for applying machine learning to biological data goes through four steps: Recording, including capture and storage. In this step, different information sources may be merged into a single set. Preprocessing, including cleaning and restructuring into a ready-to-analyze form.
Cancer biomarkers Diagnosis Cancer_biomarkers > Role of biomarkers in cancer research and medicine > Uses of biomarkers in cancer medicine > Diagnosis Cancer biomarkers can also be useful in establishing a specific diagnosis. This is particularly the case when there is a need to determine whether tumors are of primary or metastatic origin. To make this distinction, researchers can screen the chromosomal alterations found on cells located in the primary tumor site against those found in the secondary site. If the alterations match, the secondary tumor can be identified as metastatic; whereas if the alterations differ, the secondary tumor can be identified as a distinct primary tumor.
CaRMetal Magnetism CaRMetal > Special features > Magnetism A point can be made magnetic with a distance and a list of objects it is attracted to whenever the point is sufficiently near one or several of these objects (sufficiently near means that the distance between them is less than the minimal distance which is a property of the point, and is measured in pixel units). For example, when a point is attracted to a finite set of points, which themselves are fixed, it can explore a finite geometry.
ANNOVAR System efficiency ANNOVAR > Technical information > System efficiency Benchmarked on a modern desktop computer (3 GHz Intel Xeon CPU, 8GB memory), for 4.7 million variants, ANNOVAR requires ~4 minutes to perform gene-based functional annotation, or ~15 minutes to perform stepwise "variants reduction". It is said to be practical for performing variant annotation and variant prioritization on hundreds of human genomes in a day.ANNOVAR could be sped up by using the -thread argument which enables multi-threading so that input files could be processed in parallel.
Tissue biopsies Cancer Tissue_biopsies > Medical use > Cancer When cancer is suspected, a variety of biopsy techniques can be applied. An excisional biopsy is an attempt to remove an entire lesion. When the specimen is evaluated, in addition to diagnosis, the amount of uninvolved tissue around the lesion, the surgical margin of the specimen is examined to see if the disease has spread beyond the area biopsied. "Clear margins" or "negative margins" means that no disease was found at the edges of the biopsy specimen.
Support-vector machine Implementation Support_vector_regression > Implementation The parameters of the maximum-margin hyperplane are derived by solving the optimization. There exist several specialized algorithms for quickly solving the quadratic programming (QP) problem that arises from SVMs, mostly relying on heuristics for breaking the problem down into smaller, more manageable chunks. Another approach is to use an interior-point method that uses Newton-like iterations to find a solution of the Karush–Kuhn–Tucker conditions of the primal and dual problems. Instead of solving a sequence of broken-down problems, this approach directly solves the problem altogether.
J. Robert Oppenheimer Scientific work J._Robert_Oppenheimer > Early career > Scientific work Two years later, Carl David Anderson discovered the positron, for which he received the 1936 Nobel Prize in Physics.In the late 1930s, Oppenheimer became interested in astrophysics, most likely through his friendship with Richard Tolman, resulting in a series of papers. In the first of these, "On the Stability of Stellar Neutron Cores" (1938), co-written with Robert Serber, Oppenheimer explored the properties of white dwarfs. This was followed by a paper co-written with one of his students, George Volkoff, "On Massive Neutron Cores", which demonstrated that there was a limit, known as the Tolman–Oppenheimer–Volkoff limit, to the mass of stars beyond which they would not remain stable as neutron stars and would undergo gravitational collapse.
Chemotherapy Dosage Chemotherapy > Treatment strategies > Dosage BSA-dosed people were treated for a total of 680 months while people in the dose-adjusted group were treated for a total of 791 months. Completing the course of treatment is an important factor in achieving better treatment outcomes. Similar results were found in a study involving people with colorectal cancer who have been treated with the popular FOLFOX regimen.
MicroRNA RNA-induced silencing complex Micro_RNA > RNA-induced silencing complex The mature miRNA is part of an active RNA-induced silencing complex (RISC) containing Dicer and many associated proteins. RISC is also known as a microRNA ribonucleoprotein complex (miRNP); A RISC with incorporated miRNA is sometimes referred to as a "miRISC." Dicer processing of the pre-miRNA is thought to be coupled with unwinding of the duplex. Generally, only one strand is incorporated into the miRISC, selected on the basis of its thermodynamic instability and weaker base-pairing on the 5' end relative to the other strand.
Pulse-Doppler signal processing Track Pulse-Doppler_signal_processing > Track Other strategies are used for objects that do not satisfy Newtonian physics. Users are generally presented with several displays that show information from track data and raw detected signals.
Glossary of electrical and electronics engineering N Glossary_of_electrical_and_electronics_engineering > N network protectorA type of circuit breaker used to isolate a fault from a multi-transformer supply network. neural networksA network of individual logic elements in multiple layers that emulates some of the behavior of a biological nervous system; a technique in artificial intelligence. nodal analysisA technique for analysis of currents in an electrical network.
Solubility constant Definitions Solubility_constant > Definitions Units of solubility may be molar (mol dm−3) or expressed as mass per unit volume, such as μg mL−1. Solubility is temperature dependent. A solution containing a higher concentration of solute than the solubility is said to be supersaturated.
Asymmetric information Summary Asymmetric_information If the buyer has more information, the power to manipulate the transaction will be represented by the scale leaning towards the buyer's side. Information asymmetry extends to non-economic behaviour. Private firms have better information than regulators about the actions that they would take in the absence of regulation, and the effectiveness of a regulation may be undermined.
EC-hippocampus system Summary EC-hippocampus_system The entorhinal cortex (EC) is a major part of the hippocampal formation of the brain, and is reciprocally connected with the hippocampus.The hippocampal formation, which consists of the hippocampus, perirhinal cortex, the dentate gyrus, the subicular areas and the EC forms one of the most important parts of the limbic system. The entorhinal cortex is an infolding of the parahippocampal gyrus into the inferior (temporal) horn of the lateral ventricle.
Schema-agnostic databases Example Schema-agnostic_databases > Schema-agnostic queries > Schema-agnostic keyword queries > Example "Bill Clinton daughter married to" "Books by William Goldman with more than 300 pages"
Discovery and development of beta2 agonists Asthma Discovery_and_development_of_beta2_agonists > Clinical use > Asthma β2-agonists are used to treat asthma, an inflammatory disease in the airways. The inflammation makes the bronchia sensitive to some factors in the environment, which causes bronchoconstriction. When this constriction occurs, the airways get narrow and it causes symptoms like wheezing, chest tightness, shortness of breath, and coughing. The muscles in the airways tighten, and cells in the airway start to produce more mucus than usual, which narrows the airways even more. The symptoms often start in childhood, but it can start at any age .
Remote-area power supply Summary Stand-alone_power_system A stand-alone power system (SAPS or SPS), also known as remote area power supply (RAPS), is an off-the-grid electricity system for locations that are not fitted with an electricity distribution system. Typical SAPS include one or more methods of electricity generation, energy storage, and regulation. Electricity is typically generated by one or more of the following methods: Photovoltaic system using solar panels Wind turbine Geothermal source Micro combined heat and power Micro hydro Diesel or biofuel generator Thermoelectric generator (TEGs)Storage is typically implemented as a battery bank, but other solutions exist including fuel cells. Power drawn directly from the battery will be direct current extra-low voltage (DC ELV), and this is used especially for lighting as well as for DC appliances. An inverter is used to generate AC low voltage, which more typical appliances can be used with. Stand-alone photovoltaic power systems are independent of the utility grid and may use solar panels only or may be used in conjunction with a diesel generator, a wind turbine or batteries.
Formation constant Theory Formation_constant > Theory {\displaystyle \beta _{pq...}={\frac {}{^{p}^{q}...}}} The definition can easily be extended to include any number of reagents. The reagents need not always be a metal and a ligand but can be any species which form a complex. Stability constants defined in this way, are association constants.
Eventual consistency Conflict resolution Eventual_consistency > Conflict resolution In order to ensure replica convergence, a system must reconcile differences between multiple copies of distributed data. This consists of two parts: exchanging versions or updates of data between servers (often known as anti-entropy); and choosing an appropriate final state when concurrent updates have occurred, called reconciliation.The most appropriate approach to reconciliation depends on the application. A widespread approach is "last writer wins". Another is to invoke a user-specified conflict handler.
Glucose-1,6-bisphosphate synthase Metabolic significance of the catalyzed reaction Glucose-1,6-bisphosphate_synthase > Metabolic significance of the catalyzed reaction It can therefore be inferred that it is possible when glucose-1-phosphate is produced, it makes glucose-1,6-bisphosphate (with glucose-1,6-bisophosphate synthase) and glucose-6-phosphate. The glucose-1,6-bisphosphate increase the activity of glycolysis, of which glucose-6-phosphate is a reagent. In addition, one of the reactants (1,3-bisphosphoglycerate) and one of the products (3-phosphoglycerate) are intermediates in the 'payoff' phase of glycolysis. In other words, two molecules involved with glucose-1,6-bisphosphate synthase are able to be both created and recycled in the glycolytic pathway. The reactant glucose 1-phosphate is an important precursor molecule in many different pathways, including glycolysis, gluconeogenesis and the pentose phosphate pathway.
Valency bonds Theory Valence_Bond_Theory > Theory For example, a bond between two s-orbital electrons is a sigma bond, because two spheres are always coaxial. In terms of bond order, single bonds have one sigma bond, double bonds consist of one sigma bond and one pi bond, and triple bonds contain one sigma bond and two pi bonds. However, the atomic orbitals for bonding may be hybrids. Often, the bonding atomic orbitals have a character of several possible types of orbitals. The methods to get an atomic orbital with the proper character for the bonding is called hybridization.
Cake number General formula Cake_number > General formula If n! denotes the factorial, and we denote the binomial coefficients by ( n k ) = n ! k ! ( n − k ) !
Protein melting temperature Summary Protein_melting_temperature Denaturation midpoint of a protein is defined as the temperature (Tm) or concentration of denaturant (Cm) at which both the folded and unfolded states are equally populated at equilibrium (assuming two-state protein folding). Tm is often determined using a thermal shift assay. If the widths of the folded and unfolded wells are assumed to be equal both these states will have identical free energies at the midpoint. However, for natural proteins this is not the case.
Scientific methodology DNA-characterizations Critical_method > Elements of the scientific method > Characterizations > DNA-characterizations The history of the discovery of the structure of DNA is a classic example of the elements of the scientific method: in 1950 it was known that genetic inheritance had a mathematical description, starting with the studies of Gregor Mendel, and that DNA contained genetic information (Oswald Avery's transforming principle). But the mechanism of storing genetic information (i.e., genes) in DNA was unclear. Researchers in Bragg's laboratory at Cambridge University made X-ray diffraction pictures of various molecules, starting with crystals of salt, and proceeding to more complicated substances.
Newtonian theory History Classical_mechanics > History Newton also enunciated the principles of conservation of momentum and angular momentum. In mechanics, Newton was also the first to provide the first correct scientific and mathematical formulation of gravity in Newton's law of universal gravitation. The combination of Newton's laws of motion and gravitation provides the fullest and most accurate description of classical mechanics.
Combination square Uses Combination_square > Uses As well as being used as a regular standalone rule or straightedge, the rule is used in combination with the different heads.
Human memory Cognitive neuroscience Human_memory > Cognitive neuroscience Encoding of episodic memory involves persistent changes in molecular structures that alter synaptic transmission between neurons. Examples of such structural changes include long-term potentiation (LTP) or spike-timing-dependent plasticity (STDP). The persistent spiking in working memory can enhance the synaptic and cellular changes in the encoding of episodic memory (Jensen and Lisman 2005).
Vaccination policy Summary Vaccine_mandates A vaccination policy is a health policy adopted in order to prevent the spread of infectious disease. These policies are generally put into place by State or local governments, but may also be set by private facilities, such as workplaces or schools. Many policies have been developed and implemented since vaccines were first made widely available. The main purpose of implementing a vaccination policy is complete eradication of a disease, as was done with smallpox.
Digital sculpting Sculpting technology Digital_sculpting > Sculpting technology The geometry used in digital sculpting programs to represent the model can vary; each offers different benefits and limitations. The majority of digital sculpting tools on the market use mesh-based geometry, in which an object is represented by an interconnected surface mesh of polygons that can be pushed and pulled around. This is somewhat similar to the physical process of beating copper plates to sculpt a scene in relief. Other digital sculpting tools use voxel-based geometry, in which the volume of the object is the basic element.
Protein Design Branch and bound Protein_Design > Algorithms > With mathematical guarantees > Branch and bound The protein design conformational space can be represented as a tree, where the protein residues are ordered in an arbitrary way, and the tree branches at each of the rotamers in a residue. Branch and bound algorithms use this representation to efficiently explore the conformation tree: At each branching, branch and bound algorithms bound the conformation space and explore only the promising branches.A popular search algorithm for protein design is the A* search algorithm. A* computes a lower-bound score on each partial tree path that lower bounds (with guarantees) the energy of each of the expanded rotamers. Each partial conformation is added to a priority queue and at each iteration the partial path with the lowest lower bound is popped from the queue and expanded.
Nonalcoholic fatty liver disease Epidemiology Nonalcoholic_fatty_liver_disease > Epidemiology MAFLD incidence is rapidly rising, along with obesity and diabetes, and has become the most common cause of liver disease in developed countries, for adults, teenagers, and children. The percentage of people with MAFLD ranges from 9 to 36.9% in different parts of the world. Approximately 20% of the United States and 25% of the Asia-Pacific populations have non-alcoholic fatty liver. Similar prevalence can be found in Europe, although less data is available.
Chemical derivative Summary Derivative_(chemistry) In analytical chemistry, derivatization can be used to convert analytes into other species for improving detection. For example, polar groups such as N-H or O-H can be converted into less polar groups. This reaction reduces the boiling point of the molecule, allowing non-volatile compounds to be analyzed by gas chromatography.
Quantum superposition Analogy with probability Quantum_linear_superposition > Theory > Analogy with probability In probability theory there is a similar principle. If a system has a probabilistic description, this description gives the probability of any configuration, and given any two different configurations, there is a state which is partly this and partly that, with positive real number coefficients, the probabilities, which say how much of each there is. For example, if we have a probability distribution for where a particle is, it is described by the "state" ∑ x ρ ( x ) \| x ⟩ {\displaystyle \sum _{x}\rho (x)\|x\rangle } Where ρ {\displaystyle \rho } is the probability density function, a positive number that measures the probability that the particle will be found at a certain location. The evolution equation is also linear in probability, for fundamental reasons.
Medicinal chemist Training Medicinal_chemist > Training Medicinal chemistry is by nature an interdisciplinary science, and practitioners have a strong background in organic chemistry, which must eventually be coupled with a broad understanding of biological concepts related to cellular drug targets. Scientists in medicinal chemistry work are principally industrial scientists (but see following), working as part of an interdisciplinary team that uses their chemistry abilities, especially, their synthetic abilities, to use chemical principles to design effective therapeutic agents. The length of training is intense, with practitioners often required to attain a 4-year bachelor's degree followed by a 4-6 year Ph.D.
Compiler design Summary Compiler_theory A compiler-compiler is a compiler that produces a compiler (or part of one), often in a generic and reusable way so as to be able to produce many differing compilers. A compiler is likely to perform some or all of the following operations, often called phases: preprocessing, lexical analysis, parsing, semantic analysis (syntax-directed translation), conversion of input programs to an intermediate representation, code optimization and machine specific code generation. Compilers generally implement these phases as modular components, promoting efficient design and correctness of transformations of source input to target output.
Algorithms-Aided Design (AAD) Summary Algorithms-Aided_Design_(AAD) Algorithms-Aided Design (AAD) is the use of specific algorithms-editors to assist in the creation, modification, analysis, or optimization of a design. The algorithms-editors are usually integrated with 3D modeling packages and read several programming languages, both scripted or visual (RhinoScript®, Grasshopper®, MEL®, C#, Python®). The Algorithms-Aided Design allows designers to overcome the limitations of traditional CAD software and 3D computer graphics software, reaching a level of complexity which is beyond the human possibility to interact with digital objects. The acronym appears for the first time in the book AAD Algorithms-Aided Design, Parametric Strategies using Grasshopper, published by Arturo Tedeschi in 2014.
Triangular form Summary Triangular_matrices In mathematics, a triangular matrix is a special kind of square matrix. A square matrix is called lower triangular if all the entries above the main diagonal are zero. Similarly, a square matrix is called upper triangular if all the entries below the main diagonal are zero. Because matrix equations with triangular matrices are easier to solve, they are very important in numerical analysis. By the LU decomposition algorithm, an invertible matrix may be written as the product of a lower triangular matrix L and an upper triangular matrix U if and only if all its leading principal minors are non-zero.
Drain (transistor) Metal-oxide-semiconductor FET (MOSFET) Field-effect_transistor > History > Metal-oxide-semiconductor FET (MOSFET) With its high scalability, and much lower power consumption and higher density than bipolar junction transistors, the MOSFET made it possible to build high-density integrated circuits. The MOSFET is also capable of handling higher power than the JFET.
Multiple-instance learning Generalizations Multiple-instance_learning > Generalizations Much like the standard assumption, MI regression assumes there is one instance in each bag, called the "prime instance", which determines the label for the bag (up to noise). The ideal goal of MI regression would be to find a hyperplane which minimizes the square loss of the prime instances in each bag, but the prime instances are hidden. In fact, Ray and Page (2001) show that finding a best fit hyperplane which fits one instance from each bag is intractable if there are fewer than three instances per bag, and instead develop an algorithm for approximation. Many of the algorithms developed for MI classification may also provide good approximations to the MI regression problem.
Kearns–Sayre syndrome Genetics Kearns–Sayre_syndrome > Genetics This cellular energy deficit manifests most readily in tissues that rely heavily upon aerobic metabolism such as the brain, skeletal and cardiac muscles, sensory organs, and kidneys. This is one factor involved in the presentation of mitochondrial diseases.There are other factors involved in the manifestation of a mitochondrial disease besides the size and location of a mutation. Mitochondria replicate during each cell division during gestation and throughout life.
Private set intersection Summary Private_set_intersection The delegated PSI category can be further divided into two classes: (a) those that support one-off delegation, and (b) those that support repeated delegation. The PSI protocols that support one-off delegation require the data owner to re-encode its data and send the encoded data to the server for each computation, e.g., . Those that support repeated delegation allow the data owners to upload their (encrypted) data to the server only once, and then re-use it many times for each computation carried out but the server, e.g., Recently, researchers have proposed a variant of PSI protocol (in both traditional and delegated categories) that support data update, e.g., , . This type of PSI protocol lets data owners insert/delete set elements into/from their data with low overheads and in a privacy-preserving manner. == References ==
Windows Driver Frameworks Varieties Windows_Driver_Frameworks > Varieties There are three types of WDF drivers: Kernel-Mode Driver Framework, for writing standard kernel-mode device drivers User-Mode Driver Framework v1, for writing user-mode drivers using a C++ COM-based API User-Mode Driver Framework v2, for writing user-mode drivers with syntactic parity to KMDFWDF also includes a set of static verification tools for use by driver writers. These tools examine driver code for common errors and/or simulate the code of a driver in order to identify problems that are both difficult to detect and difficult to test for.
Analytical skill The 6 types of inductive reasoning Analytical_skill > Logical Reasoning > Inductive Reasoning > The 6 types of inductive reasoning Generalised: This manner utilises a premise on a sample set to extract a conclusion about a population. Statistical: This is a method that utilises statistics based on a large and viable random sample set that is quantifiable to strengthen conclusions and observations. Bayesian: This form adapts statistical reasoning to account for additional or new data. Analogical: This is a method that records on the foundations of shared properties between two groups, leading to a conclusion that they are also likely to share further properties. Predictive: This form of reasoning extrapolates a conclusion about the future based on a current or past sample. Causal inference: This method of reasoning is formed around a causal link between the premise and the conclusion.
NP class Why some NP problems are hard to solve NP_class > Why some NP problems are hard to solve If there is a polynomial-time algorithm for even one of them, then there is a polynomial-time algorithm for all the problems in NP. Because of this, and because dedicated research has failed to find a polynomial algorithm for any NP-complete problem, once a problem has been proven to be NP-complete, this is widely regarded as a sign that a polynomial algorithm for this problem is unlikely to exist. However, in practical uses, instead of spending computational resources looking for an optimal solution, a good enough (but potentially suboptimal) solution may often be found in polynomial time. Also, the real-life applications of some problems are easier than their theoretical equivalents.
Algorithm characterization 1952 "Turing's thesis" Algorithm_characterization > 1943, 1952 Stephen Kleene's characterization > 1952 "Turing's thesis" Thus the inclusion of "partial function" extends the notion of function to "less-perfect" functions. Total- and partial-functions may either be calculated by hand or computed by machine.
Phenotypic response surfaces Oncology Phenotypic_response_surfaces > Applications > Oncology Optimization of combination therapies is of particular importance in oncology. Conventional cancer treatments often rely on the sequential use of chemotherapy drugs, with each new drug starting as soon as the pervious agent loses efficacy. However, this methodology allows for cancerous cells, due to their rapid rate of mutation, to develop resistances to chemotherapy drugs in instances where chemotherapy drugs fail to be effective.
Plant agriculture Agricultural automation Plant_agriculture > Production > Agricultural automation FAO defines agricultural automation as the use of machinery and equipment in agricultural operations to improve their diagnosis, decision-making or performing, reducing the drudgery of agricultural work or improving the timeliness, and potentially the precision, of agricultural operations.The technological evolution in agriculture has involved a progressive move from manual tools to animal traction, to motorized mechanization, to digital equipment and finally, to robotics with artificial intelligence (AI). Motorized mechanization using engine power automates the performance of agricultural operations such as ploughing and milking. With digital automation technologies, it also becomes possible to automate diagnosis and decision-making of agricultural operations.
Sequence graph Construction Sequence_graph > Construction Before constructing a sequence graph, there must be at least two genomes represented as directed graphs with edges as threads (adjacency edges) and vertices as DNA segments. The genomes should be labeled P and Q, while the sequence graph is labeled as BreakpointGraph(P, Q).The directional vertices of Q and their edges are arranged in the order of P. Once completed, the edges of Q are reconnected to their original vertices. After all edges have been matched the vertex directions are removed and instead each vertex is labeled as vh (vertex head) and vt (vertex tail). Similarity between genomes is represented by the number of cycles (independent systems) within the sequence graph. The number of cycles is equal to cycles (P, Q). The max number of cycles possible is equal to the number of vertices in the sequence graph.
Very Large Telescope Instruments Mid-IR_Interferometric_instrument > Technical details > Instruments Transiting planets are almost always close-in planets that are hot and radiate most of their light in the infrared (IR). Furthermore, the IR is a spectral region where lines of molecular gases like carbon monoxide (CO), ammonia (NH3), and methane (CH4), etc. are expected from the exoplanetary atmosphere. This important wavelength region is covered by CRIRES+, which will additionally allow tracking multiple absorption lines simultaneously.
Photooxygenation States of molecular oxygen Photooxygenation > Background > States of molecular oxygen In classical Lewis structures, molecular oxygen, O2, is depicted as having a double bond between the two oxygen atoms. However, the molecular orbitals of O2 are actually more complex than Lewis structures seem to suggest. The highest occupied molecular orbital (HOMO) of O2 is a pair of degenerate antibonding π orbitals, π2px* and π2py*, which are both singly occupied by spin unpaired electrons.
Marine prokaryote Symbiosis Marine_prokaryote > Symbiosis Glands on the worm's back secrete a mucus on which the bacteria feed, a form of symbiosis. Endosymbiont bacteria are bacteria that live within the body or cells of another organism. Some types of cyanobacteria are endosymbiont and cyanobacteria have been found to possess genes that enable them to undergo nitrogen fixation.Organisms typically establish a symbiotic relationship due to their limited availability of resources in their habitat or due to a limitation of their food source.
Enzyme induction and inhibition History Enzyme_induction_and_inhibition > History In the late 1950s and early 1960s, the French molecular biologists François Jacob and Jacques Monod became the first to explain enzyme induction, in the context of the lac operon of Escherichia coli. In the absence of lactose, the constitutively expressed lac repressor protein binds to the operator region of the DNA and prevents the transcription of the operon genes. When present, lactose binds to the lac repressor, causing it to separate from the DNA and thereby enabling transcription to occur.
Work hardened Theory Work_hardened > Theory Instead, the dislocations accumulate, interact with one another, and serve as pinning points or obstacles that significantly impede their motion. This leads to an increase in the yield strength of the material and a subsequent decrease in ductility. Such deformation increases the concentration of dislocations which may subsequently form low-angle grain boundaries surrounding sub-grains.
Data auditing Summary Data_auditing Data auditing is the process of conducting a data audit to assess how company's data is fit for given purpose. This involves profiling the data and assessing the impact of poor quality data on the organization's performance and profits. It can include the determination of the clarity of the data sources and can be applied in the way banks and rating agencies perform due diligence with regard to the treatment of raw data given by firms, particularly the identification of faulty data.Data auditing can also refer to the audit of a system to determine its efficacy in performing its function.
Direct policy search Model-based algorithms Direct_policy_search > Algorithms for control learning > Model-based algorithms Finally, all of the above methods can be combined with algorithms that first learn a model. For instance, the Dyna algorithm learns a model from experience, and uses that to provide more modelled transitions for a value function, in addition to the real transitions. Such methods can sometimes be extended to use of non-parametric models, such as when the transitions are simply stored and 'replayed' to the learning algorithm. There are other ways to use models than to update a value function. For instance, in model predictive control the model is used to update the behavior directly.
Aggregation method Summary Aggregation_problem In economics, an aggregate is a summary measure. It replaces a vector that is composed of many real numbers by a single real number, or a scalar. Consequently, there occur various problems that are inherent in the formulations that use aggregated variables.The aggregation problem is the difficult problem of finding a valid way to treat an empirical or theoretical aggregate as if it reacted like a less-aggregated measure, say, about behavior of an individual agent as described in general microeconomic theory (see Representative agent, Heterogeneity in economics). The second meaning of "aggregation problem" is the theoretical difficulty in using and treating laws and theorems that include aggregate variables.
Automata-based programming Procedural Automata-based_programming > Example > Automata-based program > Procedural Besides that, there is only one loop instead of the four the traditional version had. The body of the while loop is the automaton step and the loop itself is the cycle of the automaton step. The program implements the work of a finite-state machine shown in the state diagram.
Order of a graph Tree Adjacency_relation > Types of graph > Tree A tree is an undirected graph in which any two vertices are connected by exactly one path, or equivalently a connected acyclic undirected graph. A forest is an undirected graph in which any two vertices are connected by at most one path, or equivalently an acyclic undirected graph, or equivalently a disjoint union of trees.
Direct Fusion Drive Summary Direct_Fusion_Drive Direct Fusion Drive (DFD) is a conceptual, low radioactivity, nuclear-fusion rocket engine, designed to produce both thrust and electric power for interplanetary spacecraft. The concept is based on the Princeton field-reversed configuration reactor, invented in 2002 by Samuel A. Cohen, and is being modeled and experimentally tested at Princeton Plasma Physics Laboratory, a U.S. Department of Energy facility. It is also modeled and evaluated by Princeton Satellite Systems. As of 2018, the concept entered Phase II, a simulation phase, to further advance the design.
Philosophy of physics Uncertainty principle Philosophy_of_physics > Philosophy of quantum mechanics > Uncertainty principle The uncertainty principle is a mathematical relation asserting an upper limit to the accuracy of the simultaneous measurement of any pair of conjugate variables, e.g. position and momentum. In the formalism of operator notation, this limit is the evaluation of the commutator of the variables' corresponding operators. The uncertainty principle arose as an answer to the question: How does one measure the location of an electron around a nucleus if an electron is a wave? When quantum mechanics was developed, it was seen to be a relation between the classical and quantum descriptions of a system using wave mechanics.
Gorilla arm Infrared grid Gorilla_arm > Technologies > Infrared grid An infrared touchscreen uses an array of X-Y infrared LED and photodetector pairs around the edges of the screen to detect a disruption in the pattern of LED beams. These LED beams cross each other in vertical and horizontal patterns. This helps the sensors pick up the exact location of the touch.
DNA damage Rate of evolutionary change DNA_damage_checkpoints > Evolution > Rate of evolutionary change On some occasions, DNA damage is not repaired or is repaired by an error-prone mechanism that results in a change from the original sequence. When this occurs, mutations may propagate into the genomes of the cell's progeny. Should such an event occur in a germ line cell that will eventually produce a gamete, the mutation has the potential to be passed on to the organism's offspring. The rate of evolution in a particular species (or, in a particular gene) is a function of the rate of mutation.
Ray tracing (physics) Summary Ray_tracing_(physics) More detailed analysis can be performed by using a computer to propagate many rays. When applied to problems of electromagnetic radiation, ray tracing often relies on approximate solutions to Maxwell's equations that are valid as long as the light waves propagate through and around objects whose dimensions are much greater than the light's wavelength. Ray theory does not describe phenomena such as interference and diffraction, which require wave theory (involving the phase of the wave).
Prime factor History Prime_divisor > History A weaker consequence of this high density of primes was Bertrand's postulate, that for every n > 1 {\displaystyle n>1} there is a prime between n {\displaystyle n} and 2 n {\displaystyle 2n} , proved in 1852 by Pafnuty Chebyshev. Ideas of Bernhard Riemann in his 1859 paper on the zeta-function sketched an outline for proving the conjecture of Legendre and Gauss. Although the closely related Riemann hypothesis remains unproven, Riemann's outline was completed in 1896 by Hadamard and de la Vallée Poussin, and the result is now known as the prime number theorem.
Thermal inertia Volumetric heat capacity of solids Thermal_inertia > Volumetric heat capacity of solids The molar volume of solid elements is very roughly constant, and (even more reliably) so also is the molar heat capacity for most solid substances. These two factors determine the volumetric heat capacity, which as a bulk property may be striking in consistency.
Quantum vacuum zero point energy Vacuum birefringence Lowest-energy_state > Experimental observations > Vacuum birefringence Yet, in theory, large nonlinear self-interaction of light due to quantum fluctuations should lead to this principle being measurably violated if the interactions are strong enough. Nearly all theories of quantum gravity predict that Lorentz invariance is not an exact symmetry of nature. It is predicted the speed at which light travels through the vacuum depends on its direction, polarization and the local strength of the magnetic field.
PER2 Main interactions PER2 > Function > Main interactions In mammals, mPER2 forms a heterodimer with mPER1, mCRY1, and mCRY2 by binding to PAS domains. The heterodimer acts to inhibit their own transcription by suppressing the CLOCK/BMAL1 complex resulting in a negative feedback loop. This negative feedback loop is essential for maintaining a functioning circadian clock.
Categorical semantics Overview Internal_language > Overview There are three important themes in the categorical approach to logic: Categorical semantics Categorical logic introduces the notion of structure valued in a category C with the classical model theoretic notion of a structure appearing in the particular case where C is the category of sets and functions. This notion has proven useful when the set-theoretic notion of a model lacks generality and/or is inconvenient. R.A.G.
Hypertensive retinopathy Management Hypertensive_retinopathy > Management A major aim of treatment is to prevent, limit, or reverse target organ damage by lowering the person's high blood pressure to reduce the risk of cardiovascular disease and death. Treatment with antihypertensive medications may be required to control the high blood pressure.
Pharmacodynamics of testosterone Cardiovascular disease Pharmacodynamics_of_testosterone > Side effects > Long-term adverse effects > Cardiovascular disease Adverse effects of testosterone supplementation may include increased cardiovascular events (including strokes and heart attacks) and deaths based on three peer-reviewed studies involving men taking testosterone replacement. In addition, an increase of 30% in deaths and heart attacks in older men has been reported. Due to an increased incidence of adverse cardiovascular events compared to a placebo group, a Testosterone in Older Men with Mobility Limitations (TOM) trial (a National Institute of Aging randomized trial) was halted early by the Data Safety and Monitoring Committee.
Baudhayana sequences Circling the square Baudhayana_sequences > Baudhāyana Śulvasūtra > Circling the square Another problem tackled by Baudhāyana is that of finding a circle whose area is the same as that of a square (the reverse of squaring the circle). His sūtra i.58 gives this construction: Draw half its diagonal about the centre towards the East–West line; then describe a circle together with a third part of that which lies outside the square. Explanation: Draw the half-diagonal of the square, which is larger than the half-side by x = a 2 2 − a 2 {\displaystyle x={a \over 2}{\sqrt {2}}-{a \over 2}} . Then draw a circle with radius a 2 + x 3 {\displaystyle {a \over 2}+{x \over 3}} , or a 2 + a 6 ( 2 − 1 ) {\displaystyle {a \over 2}+{a \over 6}({\sqrt {2}}-1)} , which equals a 6 ( 2 + 2 ) {\displaystyle {a \over 6}(2+{\sqrt {2}})} . Now ( 2 + 2 ) 2 ≈ 11.66 ≈ 36.6 π {\displaystyle (2+{\sqrt {2}})^{2}\approx 11.66\approx {36.6 \over \pi }} , so the area π r 2 ≈ π × a 2 6 2 × 36.6 π ≈ a 2 {\displaystyle {\pi }r^{2}\approx \pi \times {a^{2} \over 6^{2}}\times {36.6 \over \pi }\approx a^{2}} .
Internet influences on communities Influences on communities Internet_influences_on_communities > Social capital > Influences on communities Information and communication technologies (ICT) affect various aspects of communities, including communications, social capital, friendships and trust. Internet has the most influence on communities due to its interactive nature and wide usage. According to Katz, Rice, Aspden (2001) “Internet has unique, even transformational qualities as a communication channel, including relative anonymity and the ability to easily link with others who have similar interests, values, and beliefs”.Internet, and computer-mediated communication supports and accelerates ways how people operate at the centers of partial, personal communities, and switching rapidly and frequently between different groups (Wellman, 1996).
Perineuronal net Neuroprotection Perineuronal_net > Functions > Neuroprotection In the site of ChABC injections, there was profuse outgrowth of the terminal branches of Purkinje cell neurons. However, myelinated axon segments were not affected and remained normal. Purkinje axon sprouting was first evident four days after the degradation of CSPGs. Within 42 days, the expression of CSPGs gradually recovered, at which point axon outgrowth regressed, indicating that there was no significant formation of stable synaptic contacts. While CSPGs are very important in neuroprotection, this indicates that CSPGs may not be the only molecules important for the preservation of anatomical plasticity.
Long non coding RNA Regulating basal transcription machinery Telomeric_non-coding_RNAs > Functions > In the regulation of gene transcription > Regulating basal transcription machinery The ability to quickly mediate global changes is also apparent in the rapid expression of non-coding repetitive sequences. The short interspersed nuclear (SINE) Alu elements in humans and analogous B1 and B2 elements in mice have succeeded in becoming the most abundant mobile elements within the genomes, comprising ~10% of the human and ~6% of the mouse genome, respectively. These elements are transcribed as ncRNAs by RNAP III in response to environmental stresses such as heat shock, where they then bind to RNAP II with high affinity and prevent the formation of active pre-initiation complexes.
RLC Circuit Sinusoidal steady state RLC_Circuit > Series circuit > Laplace domain > Sinusoidal steady state Sinusoidal steady state is represented by letting s = jω, where j is the imaginary unit. Taking the magnitude of the above equation with this substitution: \| Y ( j ω ) \| = 1 R 2 + ( ω L − 1 ω C ) 2 . {\displaystyle {\big \|}Y(j\omega ){\big \|}={\frac {1}{{\sqrt {R^{2}+\left(\omega L-{\frac {1}{\,\omega C\,}}\right)^{2}}}\,}}\;.} and the current as a function of ω can be found from \| I ( j ω ) \| = \| Y ( j ω ) \| ⋅ \| V ( j ω ) \| .
Dimensional modeling Benefits of dimensional modeling Dimensional_modeling > Benefits of dimensional modeling In normalized models, data is divided into many discrete entities and even a simple business process might result in dozens of tables joined together in a complex way. Query performance. Dimensional models are more denormalized and optimized for data querying, while normalized models seek to eliminate data redundancies and are optimized for transaction loading and updating.
Stroma (fluid) Summary Stroma_(fluid) The series of biochemical redox reactions which take place in the stroma are collectively called the Calvin cycle or light-independent reactions. There are three phases: carbon fixation, reduction reactions, and ribulose 1,5-bisphosphate (RuBP) regeneration. The stroma is also the location of chloroplast DNA and chloroplast ribosomes, and thus also the location of molecular processes including chloroplast DNA replication, and transcription/translation of some chloroplast proteins.
Histone-Modifying Enzymes Cancer Histone-modifying_enzyme > Role in research > Cancer Alterations in the functions of histone-modifying enzymes deregulate the control of chromatin-based processes, ultimately leading to oncogenic transformation and cancer. Both DNA methylation and histone modifications show patterns of distribution in cancer cells. These epigenetic alterations may occur at different stages of tumourigenesis and thus contribute to both the development and/or progression of cancer.
Personal identity Locke's conception Personal_identity > Continuity of consciousness > Locke's conception Neither is self-identity founded on the body substance, argues Locke, as the body may change while the person remains the same. Even the identity of animals is not founded on their body: "animal identity is preserved in identity of life, and not of substance," as the body of the animal grows and changes during its life. On the other hand, identity of humans is based on their consciousness.This border case leads to this problematic thought that since personal identity is based on consciousness, and only oneself can be aware of one's consciousness, exterior human judges may never know if they are really judging—and punishing—the same person, or simply the same body.
Cell fate Cell fate Cell_fate_determination > Cell fate Transplantation experiments can also be used in conjunction with the genetic manipulation and lineage tracing. Newer cell fate determination techniques include lineage tracing performed using inducible Cre-lox transgenic mice, where specific cell populations can be experimentally mapped using reporters like brainbow, a colorful reporter that is useful in the brain and other tissues to follow the differentiation path of a cell.During embryogenesis, for a number of cell cleavages (the specific number depends on the type of organism) all the cells of an embryo will be morphologically and developmentally equivalent. This means, each cell has the same development potential and all cells are essentially interchangeable, thus establishing an equivalence group.
Scapegoat tree Insertion Scapegoat_tree > Operations > Insertion Insertion is implemented with the same basic ideas as an unbalanced binary search tree, however with a few significant changes. When finding the insertion point, the depth of the new node must also be recorded. This is implemented via a simple counter that gets incremented during each iteration of the lookup, effectively counting the number of edges between the root and the inserted node. If this node violates the α-height-balance property (defined above), a rebalance is required.
Gregory Bateson Ecological anthropology and cybernetics Gregory_Bateson > Work > Ecological anthropology and cybernetics In his book Steps to an Ecology of Mind, Bateson applied cybernetics to the field of ecological anthropology and the concept of homeostasis. He saw the world as a series of systems containing those of individuals, societies and ecosystems. Within each system is found competition and dependency.
Positive displacement meter Gear Positive_displacement_meter > Types > Gear Gear flow meters rely on internal gears rotating as fluid passes through them. There are various types of gear meters named mostly for the shape of the internal components Oval gear Two rotating oval gears with synchronized teeth “squeeze” a finite amount of fluid through the meter for each revolution.With oval gear flow meters, two oval gears or rotors are mounted inside a cylinder. As the fluid flows through the cylinder, the pressure of the fluid causes the rotors to rotate. As flow rate increases, so does the rotational speed of the rotors.
Causal dynamical triangulation Related theories Causal_dynamical_triangulation > Related theories Another approach to quantum gravity that is closely related to causal dynamical triangulation is called causal sets. Both CDT and causal sets attempt to model the spacetime with a discrete causal structure. The main difference between the two is that the causal set approach is relatively general, whereas CDT assumes a more specific relationship between the lattice of spacetime events and geometry.
Nuclear DNA Structure Nuclear_genome > Structure Nucleotides are distinguished by their bases: purines, large bases that include adenine and guanine; and pyrimidines, small bases that include thymine and cytosine. Chargaff's rules state that adenine always pairs with thymine, and guanine always with cytosine. The phosphate groups are held together by a phosphodiester bond and the bases are held together by hydrogen bonds.
.3ds Structure .3ds > Structure 3ds is a binary file format. The format is based in chunks, where each section of data is embedded in a block that contains a chunk identifier and the length of the data (to provide the location of the next main block), as well as the data itself. This allows parsers to skip chunks they don't recognize, and allows for extensions to the format. The chunks form a hierarchical structure, similar to an xml DOM tree.
Analysis of parallel algorithms Definitions Analysis_of_parallel_algorithms > Definitions Span law. A finite number p of processors cannot outperform an infinite number, so that Tp ≥ T∞.Using these definitions and laws, the following measures of performance can be given: Speedup is the gain in speed made by parallel execution compared to sequential execution: Sp = T1 / Tp. When the speedup is Ω(p) for p processors (using big O notation), the speedup is linear, which is optimal in simple models of computation because the work law implies that T1 / Tp ≤ p (super-linear speedup can occur in practice due to memory hierarchy effects).
Combinatorial enumeration Binary and plane trees Enumerative_combinatorics > Combinatorial structures > Binary and plane trees In binary trees, a special case of plane trees, each node can have either two or no children. Let P {\displaystyle {\mathcal {P}}} denote the family of all plane trees. Then this family can be recursively defined as follows: P = { ∙ } × Seq ( P ) {\displaystyle {\mathcal {P}}=\{\bullet \}\times \,{\mbox{Seq}}({\mathcal {P}})} In this case { ∙ } {\displaystyle \{\bullet \}} represents the family of objects consisting of one node.
Vector processors Vector processor features Vector_processors > Vector processor features This allows code with conditional statements to be vectorized. Compress and Expand – usually using a bit-mask, data is linearly compressed or expanded (redistributed) based on whether bits in the mask are set or clear, whilst always preserving the sequential order and never duplicating values (unlike Gather-Scatter aka permute). These instructions feature in AVX-512.

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