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Sextuple bond Theoretical analysis Sextuple_bond > Theoretical analysis Roos et al argue that no stable element can form bonds of higher order than a sextuple bond, because the latter corresponds to a hybrid of the s orbital and all five d orbitals, and f orbitals contract too close to the nucleus to bond in the lanthanides. Indeed, quantum mechanical calculations have revealed that the dimolybdenum bond is formed by a combination of two σ bonds, two π bonds and two δ bonds. (Also, the σ and π bonds contribute much more significantly to the sextuple bond than the δ bonds.
Flight control Hydro-mechanical Aircraft_flight_control_system > Flight control systems > Hydro-mechanical At first, only-partially boosted systems were used in which the pilot could still feel some of the aerodynamic loads on the control surfaces (feedback).A hydro-mechanical flight control system has two parts: The mechanical circuit, which links the cockpit controls with the hydraulic circuits. Like the mechanical flight control system, it consists of rods, cables, pulleys, and sometimes chains. The hydraulic circuit, which has hydraulic pumps, reservoirs, filters, pipes, valves and actuators.
Chemical indicator Naturally occurring pH indicators Acid-base_indicator > Naturally occurring pH indicators In acid soils, chemical reactions occur in the soil that make aluminium available to these plants, turning the flowers blue. In alkaline soils, these reactions cannot occur and therefore aluminium is not taken up by the plant. As a result, the flowers remain pink. Another useful natural pH indicator is the spice turmeric. It turns yellow when exposed to acids and reddish brown when in presence of an alkalis.
Eulerian finite strain tensor Derivatives of stretch Green-Lagrange_strain > Fundamental strain tensors > Derivatives of stretch Derivatives of the stretch with respect to the right Cauchy–Green deformation tensor are used to derive the stress-strain relations of many solids, particularly hyperelastic materials. These derivatives are and follow from the observations that
KEK digital accelerator Summary KEK_digital_accelerator Sense and response would be the right words to describe the principle behind the digital particle accelerator. Instead of radio-frequency cavities, a digital accelerator ring is equipped with devices called induction accelerating cells. Particles travel around the ring in a form of a bunch.
IR filter IR transmitting/passing filters in photography Infrared_filter > IR transmitting/passing filters in photography Such sensors may extend to 1000 nm. Digital cameras are usually equipped with IR-blocking filters to prevent unnatural-looking images. IR-transmitting (passing) filters, or removal of factory IR-blocking filters, are commonly used in infrared photography to pass infrared light and block visible and ultraviolet light.
Computer Memory Protected memory Off-chip_memory > Management > Protected memory At times programs intentionally alter the memory used by other programs. This is done by viruses and malware to take over computers. It may also be used benignly by desirable programs which are intended to modify other programs, debuggers, for example, to insert breakpoints or hooks.
Arbitrium Regulation Arbitrium > Regulation The mature protein is transported to neighboring bacteria using the oligopeptide permease (OPP) transporter channel. The OPP transport channel is capable of transporting peptides inside the bacteria cell with no specific size, composition, charge, or sequence. Once inside, the mature AimP binds to the AimR receptor and regulates its activity.
Electronics engineering Specialist areas Electronic_Engineering > Specialist areas For analog signals, signal processing may involve the amplification and filtering of audio signals for audio equipment and the modulation and demodulation of radio frequency signals for telecommunications. For digital signals, signal processing may involve compression, error checking and error detection, and correction. Telecommunications engineering deals with the transmission of information across a medium such as a co-axial cable, an optical fiber, or free space.
Premature aging Bloom syndrome Progeroid_syndromes > Defects in DNA repair > RecQ-associated PS > Bloom syndrome During this time, the homologous (corresponding) copies are in close physical proximity to each other, allowing them to 'cross' and exchange genetic information, a process called homologous recombination. Defective homologous recombination can cause mutation and genetic instability. Such defective recombination can introduce gaps and breaks within the genome and disrupt the function of genes, possibly causing growth retardation, aging and elevated risk of cancer.
Transcription inhibitor Summary Transcription_initiation Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). mRNA comprises only 1–3% of total RNA samples.
Integrity checker Authenticity verification File_verification > Authenticity verification For this purpose, cryptographic hash functions are employed often. As long as the hash sums cannot be tampered with — for example, if they are communicated over a secure channel — the files can be presumed to be intact. Alternatively, digital signatures can be employed to assure tamper resistance.
Nonrival good Non-rivalry Rivalry_(economics) > Non-rivalry In fact, certain types of intellectual property become more valuable as more people consume them (anti-rival). For example, the more people use a particular language, the more valuable that language becomes. Non-rivalry does not imply that the total production costs are low, but that the marginal production costs are zero.
Cluster headache History Cluster_headaches > History They had found no relief from the usual methods of treatment. Their pain was so severe that several of them had to be constantly watched for fear of suicide. Most of them were willing to submit to any operation which might bring relief." CH has alternately been called erythroprosopalgia of Bing, ciliary neuralgia, erythromelalgia of the head, Horton's headache, histaminic cephalalgia, petrosal neuralgia, sphenopalatine neuralgia, vidian neuralgia, Sluder's neuralgia, Sluder's syndrome, and hemicrania angioparalyticia.
Scientific field Natural sciences Scientific_discipline > Natural sciences Natural science is a branch of science concerned with the description, prediction, and understanding of natural phenomena, based on empirical evidence from observation and experimentation. Mechanisms such as peer review and repeatability of findings are used to try to ensure the validity of scientific advances. Natural science can be divided into two main branches: life science and physical science. Life science is alternatively known as biology, and physical science is subdivided into branches: physics, chemistry, astronomy and Earth science. These branches of natural science may be further divided into more specialized branches (also known as fields)
Related rates Example Related_rates > Example A 10-meter ladder is leaning against the wall of a building, and the base of the ladder is sliding away from the building at a rate of 3 meters per second. How fast is the top of the ladder sliding down the wall when the base of the ladder is 6 meters from the wall? The distance between the base of the ladder and the wall, x, and the height of the ladder on the wall, y, represent the sides of a right triangle with the ladder as the hypotenuse, h. The objective is to find dy/dt, the rate of change of y with respect to time, t, when h, x and dx/dt, the rate of change of x, are known.
China seismic intensity scale Liedu scale China_seismic_intensity_scale > Liedu scale Unlike the magnitude scales that objectively estimate the released seismic energy, liedu denotes how strongly an earthquake affects a specific place. It is determined by a combination of subjective evaluations (such as human senses and building damage) and objective kinetic measures. Building damage are further refined with a combination of descriptive qualifiers and a numeric evaluation process. The following is an unofficial translation of the Appendix I of GB/T 17742-1999. Notes about qualifiers: "very few" - <10%; "few" - 10% - 50%; "most" - 50% - 70%; "majority" - 70% - 90%; "commonly" - >90%.
Double fertilization Megagametophyte Double_fertilisation > Related structures and functions > Megagametophyte The megagametophyte, which is usually haploid, originates from the (usually diploid) megaspore mother cell, also called the megasporocyte. The next sequence of events varies, depending on the particular species, but in most species, the following events occur. The megasporocyte undergoes a meiotic cell division, producing four haploid megaspores.
Adiabatic heating Conceptual significance in thermodynamic theory Adiabatic_principle > Conceptual significance in thermodynamic theory Rather, the definition of absolute thermodynamic temperature is best left till the second law is available as a conceptual basis.In the eighteenth century, the law of conservation of energy was not yet fully formulated or established, and the nature of heat was debated. One approach to these problems was to regard heat, measured by calorimetry, as a primary substance that is conserved in quantity. By the middle of the nineteenth century, it was recognized as a form of energy, and the law of conservation of energy was thereby also recognized.
Superlubricity Summary Superlubricity In physics (specifically tribology), superlubricity is a regime of motion in which friction vanishes or very nearly vanishes. However, a "vanishing" friction level is not clear, which makes the term vague. As an ad hoc definition, a kinetic coefficient of friction less than 0.01 can be adopted.
Sweet taste Sweet receptor pathway Sweet_taste > Sweet receptor pathway To depolarize the cell, and ultimately generate a response, the body uses different cells in the taste bud that each express a receptor for the perception of sweet, sour, salty, bitter or umami. Downstream of the taste receptor, the taste cells for sweet, bitter and umami share the same intracellular signalling pathway. Incoming sweet molecules bind to their receptors, which causes a conformational change in the molecule.
Isoperimetric ratio Summary Isoperimetric_ratio In analytic geometry, the isoperimetric ratio of a simple closed curve in the Euclidean plane is the ratio L2/A, where L is the length of the curve and A is its area. It is a dimensionless quantity that is invariant under similarity transformations of the curve. According to the isoperimetric inequality, the isoperimetric ratio has its minimum value, 4π, for a circle; any other curve has a larger value. Thus, the isoperimetric ratio can be used to measure how far from circular a shape is.
Crop production Genetic engineering Crop_farming > Crop alteration and biotechnology > Genetic engineering These seeds allow the farmer to grow a crop that can be sprayed with herbicides to control weeds without harming the resistant crop. Herbicide-tolerant crops are used by farmers worldwide. With the increasing use of herbicide-tolerant crops, comes an increase in the use of glyphosate-based herbicide sprays.
CH3CH(NH2)COOH Glucose–alanine cycle CH3CH(NH2)COOH > Physiological function > Glucose–alanine cycle The alanine aminotransferase reaction takes place in reverse in the liver, where the regenerated pyruvate is used in gluconeogenesis, forming glucose which returns to the muscles through the circulation system. Glutamate in the liver enters mitochondria and is broken down by glutamate dehydrogenase into α-ketoglutarate and ammonium, which in turn participates in the urea cycle to form urea which is excreted through the kidneys.The glucose–alanine cycle enables pyruvate and glutamate to be removed from muscle and safely transported to the liver. Once there, pyruvate is used to regenerate glucose, after which the glucose returns to muscle to be metabolized for energy: this moves the energetic burden of gluconeogenesis to the liver instead of the muscle, and all available ATP in the muscle can be devoted to muscle contraction. It is a catabolic pathway, and relies upon protein breakdown in the muscle tissue. Whether and to what extent it occurs in non-mammals is unclear.
Periodic system Valence and oxidation states Periodic_tables > Periodic trends > Valence and oxidation states The valence of an element can be defined either as the number of hydrogen atoms that can combine with it to form a simple binary hydride, or as twice the number of oxygen atoms that can combine with it to form a simple binary oxide (that is, not a peroxide or a superoxide). The valences of the main-group elements are directly related to the group number: the hydrides in the main groups 1–2 and 13–17 follow the formulae MH, MH2, MH3, MH4, MH3, MH2, and finally MH. The highest oxides instead increase in valence, following the formulae M2O, MO, M2O3, MO2, M2O5, MO3, M2O7. Today the notion of valence has been extended by that of the oxidation state, which is the formal charge left on an element when all other elements in a compound have been removed as their ions.The electron configuration suggests a ready explanation from the number of electrons available for bonding, although a full explanation requires considering the energy that would be released in forming compounds with different valences rather than simply considering electron configurations alone.
God Particle Names used by physicists The_Higgs_Boson > Public discussion > Naming > Names used by physicists Of the PRL papers' authors, only the paper by Higgs explicitly offered as a prediction that a massive particle would exist and calculated some of its properties;: 167 he was therefore "the first to postulate the existence of a massive particle" according to Nature. Physicist and author Frank Close and physicist-blogger Peter Woit both comment that the paper by GHK was also completed after Higgs and Brout–Englert were submitted to Physical Review Letters,: 167 and that Higgs alone had drawn attention to a predicted massive scalar boson, while all others had focused on the massive vector bosons. : 154, 166, 175 In this way, Higgs' contribution also provided experimentalists with a crucial "concrete target" needed to test the theory.However, in Higgs' view, Brout and Englert did not explicitly mention the boson since its existence is plainly obvious in their work,: 6 while according to Guralnik the GHK paper was a complete analysis of the entire symmetry breaking mechanism whose mathematical rigour is absent from the other two papers, and a massive particle may exist in some solutions.
Aerobatic loop Summary Aerobatic_loop A spin is more complex, involving intentionally stalling a single wing, causing the plane to descend spiraling around its yaw axis in a corkscrew motion. A hammerhead (also known as a stall turn) is performed by pulling the aircraft up until it is pointing straight up (much like the beginning of a loop), but the pilot continues to fly straight up until their airspeed has dropped to a certain critical point. The pilot then uses the rudder to rotate the aircraft around its yaw axis until it has turned 180deg and is pointing straight down, facing the direction from which the aircraft came. The aircraft gains speed, and the pilot continues and returns to level flight, travelling in the opposite direction from which the maneuver began. It is also known as a "tailslide", from the yawing turn, which is different from the typical method of turning an aircraft in the pitch axis.
Moroidin Anti-mitotic agent Moroidin > Toxicity > Anti-mitotic agent Moroidin has shown to have anti-mitotic properties, chiefly by inhibiting the polymerization of tubulin. Tubulin protein polymers are the major component of microtubules. During mitosis, microtubules form the organizing structure called the mitotic apparatus, which captures, aligns, and separates chromosomes. The proper alignment and separation of chromosomes is critical to ensure that cells divide their genetic material equally between daughter cells.
RNA therapeutics Vaccines RNA_therapeutics > mRNA > Applications > Vaccines One of the other ways is injecting a two-component vaccine which is containing an mRNA adjuvant and naked IVT mRNA encoding influenza hemagglutinin antigen only or in combination with neuraminidase encoding IVT mRNA.For example, for the HIV treatment, vaccines are using DCs transfected with IVT mRNA that is encoding HIV proteins. There are a few phase I and II clinical trials using IVT mRNA encoding combinations and it shows that antigen-specific CD8+ and CD4+ T cell responses can be induced. However, no antiviral effects have been observed in the clinical trial.One of the other mRNA vaccines is for COVID-19. The Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) outbreaks in December 2019 and spread all over the world, causing a pandemic of respiratory illness designated coronavirus disease 2019 (COVID-19). The Moderna COVID-19 vaccine, manufactured by Moderna since 2020, is a lipid nanoparticle (LNP) encapsulated mRNA-based vaccine that encodes for a full-length, prefusion stabilized spike(S)-2P antigen of SARS-CoV-2 with a transmembrane anchor.
Software observability Metrics Software_observability > Telemetry types > Metrics Application developers choose what kind of metrics to instrument their software with before it is released. Examples of common metrics include: number of HTTP requests per second; total number of query failures; database size in bytes; time in seconds since last garbage collection.Monitoring tools are typically configured to emit alerts when certain metric values exceed set thresholds. Thresholds are set based on knowledge about normal operating conditions and experience. Metrics have limitations: when a previously unknown issue is encountered, it is impossible to add new metrics without shipping new code. Furthermore, their cardinality can quickly explode the size of telemetry data.
Planimeter Polar coordinates Planimeter > Mathematical derivation > Polar coordinates The connection with Green's theorem can be understood in terms of integration in polar coordinates: in polar coordinates, area is computed by the integral ∫ θ 1 2 ( r ( θ ) ) 2 d θ , {\textstyle \int _{\theta }{\tfrac {1}{2}}(r(\theta ))^{2}\,d\theta ,} where the form being integrated is quadratic in r, meaning that the rate at which area changes with respect to change in angle varies quadratically with the radius. For a parametric equation in polar coordinates, where both r and θ vary as a function of time, this becomes For a polar planimeter the total rotation of the wheel is proportional to ∫ t r ( t ) θ ˙ ( t ) d t , {\textstyle \int _{t}r(t)\,{\dot {\theta }}(t)\,dt,} as the rotation is proportional to the distance traveled, which at any point in time is proportional to radius and to change in angle, as in the circumference of a circle ( ∫ r d θ = 2 π r {\textstyle \int r\,d\theta =2\pi r} ). This last integrand r ( t ) θ ˙ ( t ) {\textstyle r(t)\,{\dot {\theta }}(t)} can be recognized as the derivative of the earlier integrand 1 2 ( r ( t ) ) 2 θ ˙ ( t ) {\textstyle {\tfrac {1}{2}}(r(t))^{2}{\dot {\theta }}(t)} (with respect to r), and shows that a polar planimeter computes the area integral in terms of the derivative, which is reflected in Green's theorem, which equates a line integral of a function on a (1-dimensional) contour to the (2-dimensional) integral of the derivative.
Concatenative programming language Summary Concatenative_programming_language A concatenative programming language is a point-free computer programming language in which all expressions denote functions, and the juxtaposition of expressions denotes function composition. Concatenative programming replaces function application, which is common in other programming styles, with function composition as the default way to build subroutines.
Reinforced Concrete Common failure modes of steel reinforced concrete Reinforced_Concrete > Common failure modes of steel reinforced concrete Reinforced concrete can fail due to inadequate strength, leading to mechanical failure, or due to a reduction in its durability. Corrosion and freeze/thaw cycles may damage poorly designed or constructed reinforced concrete. When rebar corrodes, the oxidation products (rust) expand and tends to flake, cracking the concrete and unbonding the rebar from the concrete. Typical mechanisms leading to durability problems are discussed below.
List of uncertainty propagation software Software List_of_uncertainty_propagation_software > Software It supports: multivariate uncertainties, complex values, correlations, vector, and matrix algebra. metRology package for R metRology is an R package to support metrological applications. Among other functions for metrology, it includes support for measurement uncertainty evaluation using algebraic and numerical differentiation and Monte Carlo methods.
Page table entry The translation process Page_table > The translation process The memory management unit (MMU) inside the CPU stores a cache of recently used mappings from the operating system's page table. This is called the translation lookaside buffer (TLB), which is an associative cache. When a virtual address needs to be translated into a physical address, the TLB is searched first. If a match is found, which is known as a TLB hit, the physical address is returned and memory access can continue.
Dummy code Data-parallel Skeleton_(computer_programming) > Parallel programming > Data-parallel To increase efficiency, a number of data sets have this operation applied to them simultaneously, before the data is structured together again at the end. ‘Forks’ are similar to ‘maps’ but they use a different operation for certain data types. This is known as multiple data parallelism. ‘Reduces’ or ‘scans’ are used to apply prefixes to a set of data, before then applying an operation upon the data. These are different to ‘maps’ as they have a set of partial results during the runtime of the method itself.
Hydrogenic atom Schrödinger solution Hydrogenic_atom > Schrödinger solution The Schrödinger equation of atoms or ions with more than one electron has not been solved analytically, because of the computational difficulty imposed by the Coulomb interaction between the electrons. Numerical methods must be applied in order to obtain (approximate) wavefunctions or other properties from quantum mechanical calculations. Due to the spherical symmetry (of the Hamiltonian), the total angular momentum J of an atom is a conserved quantity.
Orthodontic technology Additional benefits Orthodontic_technology > Functional appliances > Additional benefits Tulloch et al. (1998) found that functional appliances reduce the need for orthognathic surgery. The use of functional appliances to correct Class II malocclusion can also have psychological benefits. O’Brien at el. (2003) found that early treatment using Twin-block appliances increased the patient's self-esteem and resulted in reduced negative social encounters.
Filter bag Low- to medium-energy scrubbers Dust_collector > Wet scrubbers > Types of scrubbers > Low- to medium-energy scrubbers Wet cyclones use centrifugal force to spin the dust particles (similar to a cyclone), and throw the particulates upon the collector's wetted walls. Water introduced from the top to wet the cyclone walls carries these particles away. The wetted walls also prevent dust reentrainment. Pressure drops for these collectors range from 2 to 8 in. water (½ to 2 kPa), and the collection efficiency is good for 5 μm particles and above.
Ramer–Douglas–Peucker algorithm Algorithm Ramer–Douglas–Peucker_algorithm > Algorithm The starting curve is an ordered set of points or lines and the distance dimension ε > 0. The algorithm recursively divides the line. Initially it is given all the points between the first and last point. It automatically marks the first and last point to be kept.
Direct Rendering Manager Software architecture Kernel_Mode_Setting > Software architecture Each GPU detected by DRM is referred to as a DRM device, and a device file /dev/dri/cardX (where X is a sequential number) is created to interface with it. User-space programs that want to talk to the GPU must open this file and use ioctl calls to communicate with DRM. Different ioctls correspond to different functions of the DRM API.
Otto Heinrich Warburg Cancer hypothesis Otto_Heinrich_Warburg > Cancer hypothesis Warburg hypothesized that cancer growth is caused by tumor cells generating energy (as, e.g., adenosine triphosphate/ATP) mainly by anaerobic breakdown of glucose (known as fermentation, or anaerobic respiration). This is in contrast to healthy cells, which generate energy mainly from oxidative breakdown of pyruvate. Pyruvate is an end product of glycolysis and is oxidized within the mitochondria.
CLMUL instruction set CPUs with CLMUL instruction set CLMUL_instruction_set > CPUs with CLMUL instruction set Intel Westmere processor (March 2010). Sandy Bridge processor Ivy Bridge processor Haswell processor Broadwell processor (with increased throughput and lower latency) Skylake (and later) processor Goldmont processor AMD: Jaguar-based processors and newer Puma-based processors and newer "Heavy Equipment" processors Bulldozer-based processors Piledriver-based processors Steamroller-based processors Excavator-based processors and newer Zen processors Zen+ processors Zen2 (and later) processorsThe presence of the CLMUL instruction set can be checked by testing one of the CPU feature bits.
Neurogenesis Epigenetic modification Neurogenesis > Neurogenesis in mammals > Developmental neurogenesis > Epigenetic modification Epigenetic modifications include DNA cytosine methylation to form 5-methylcytosine and 5-methylcytosine demethylation. These modifications are critical for cell fate determination in the developing and adult mammalian brain. DNA cytosine methylation is catalyzed by DNA methyltransferases (DNMTs). Methylcytosine demethylation is catalyzed in several stages by TET enzymes that carry out oxidative reactions (e.g. 5-methylcytosine to 5-hydroxymethylcytosine) and enzymes of the DNA base excision repair (BER) pathway.
Lambek calculus Relation to context-free grammars Lambek_calculus > Lambek calculus > Relation to context-free grammars It is necessary to verify that the extra inference rules do not change the generated language. This can be done and shows that every context-free language is generated by some Lambek grammar. To show the converse, that every language generated by a Lambek grammar is context-free, is much more difficult.
Elimination (pharmacology) Summary Elimination_(pharmacology) As the acid is ionised, it cannot pass through the plasma membrane back into the blood stream and instead gets excreted with the urine. Acidifying the urine has the same effect for weakly basic drugs. On other occasions drugs combine with bile juices and enter the intestines.
Key management system Inventory Key_management_system > Inventory Some other considerations: Regulations and requirements, like PCI-DSS, demand stringent security and management of cryptographic keys and auditors are increasingly reviewing the management controls and processes in use. Private keys used with certificates must be kept secure or unauthorised individuals can intercept confidential communications or gain unauthorised access to critical systems. Failure to ensure proper segregation of duties means that admins who generate the encryption keys can use them to access sensitive, regulated data. If a certificate authority is compromised or an encryption algorithm is broken, organizations must be prepared to replace all of their certificates and keys in a matter of hours.
Manning's equation Hydraulic radius Manning_equation > Hydraulic radius The hydraulic radius is not half the hydraulic diameter as the name may suggest, but one quarter in the case of a full pipe. It is a function of the shape of the pipe, channel, or river in which the water is flowing. Hydraulic radius is also important in determining a channel's efficiency (its ability to move water and sediment), and is one of the properties used by water engineers to assess the channel's capacity.
Androgen antagonist Insulin sensitizers Androgen_antagonist > Mechanism of action > Miscellaneous > Insulin sensitizers In women with insulin resistance, such as those with polycystic ovary syndrome, androgen levels are often elevated. Metformin, an insulin-sensitizing medication, has indirect antiandrogenic effects in such women, decreasing testosterone levels by as much as 50% secondary to its beneficial effects on insulin sensitivity.
Matrix determinant lemma Application Matrix_determinant_lemma > Application If the determinant and inverse of A are already known, the formula provides a numerically cheap way to compute the determinant of A corrected by the matrix uvT. The computation is relatively cheap because the determinant of A + uvT does not have to be computed from scratch (which in general is expensive). Using unit vectors for u and/or v, individual columns, rows or elements of A may be manipulated and a correspondingly updated determinant computed relatively cheaply in this way. When the matrix determinant lemma is used in conjunction with the Sherman–Morrison formula, both the inverse and determinant may be conveniently updated together.
SnRNP Summary SnRNP snRNPs (pronounced "snurps"), or small nuclear ribonucleoproteins, are RNA-protein complexes that combine with unmodified pre-mRNA and various other proteins to form a spliceosome, a large RNA-protein molecular complex upon which splicing of pre-mRNA occurs. The action of snRNPs is essential to the removal of introns from pre-mRNA, a critical aspect of post-transcriptional modification of RNA, occurring only in the nucleus of eukaryotic cells. Additionally, U7 snRNP is not involved in splicing at all, as U7 snRNP is responsible for processing the 3′ stem-loop of histone pre-mRNA. The two essential components of snRNPs are protein molecules and RNA.
Outline of electronics Summary Outline_of_electronics The following outline is provided as an overview of and topical guide to electronics: Electronics – branch of physics, engineering and technology dealing with electrical circuits that involve active semiconductor components and associated passive interconnection technologies.
Cyclical theory Schlesinger's liberal-conservative cycle Cyclical_theory > Schlesinger's liberal-conservative cycle This process then repeats, causing cycles. Arthur Schlesinger Jr.
Data Presentation Architecture Terminology Data_presentation > Terminology Continuous variables capture the idea that measurements can always be made more precisely. While discrete variables have only a finite number of possibilities, such as a count of some outcomes or an age measured in whole years.The distinction between quantitative and categorical variables is important because the two types require different methods of visualization.
Kaṇāda (philosopher) The concept of paramanu (atom) Kaṇāda_(philosopher) > Ideas > The concept of paramanu (atom) Each substance is supposed to consist of all four kinds of atoms. Kaṇāda's conception of the atom was likely independent from the similar concept among the ancient Greeks, because of the differences between the theories. For example, Kaṇāda suggested that atoms as building blocks differ both qualitatively and quantitatively, while Greeks suggested that atoms differed only quantitatively but not qualitatively.
Ubiquitin Polyubiquitin chains Ubiquitin > Ubiquitylation > Types > Polyubiquitin chains Multi-ubiquitin chains at least four ubiquitin molecules long must be attached to a lysine residue on the condemned protein in order for it to be recognised by the 26S proteasome. This is a barrel-shape structure comprising a central proteolytic core made of four ring structures, flanked by two cylinders that selectively allow entry of ubiquitinated proteins. Once inside, the proteins are rapidly degraded into small peptides (usually 3–25 amino acid residues in length).
MAX-3SAT Theorem 1 (inapproximability) MAX-3SAT > Theorem 1 (inapproximability) The PCP theorem implies that there exists an ε > 0 such that (1-ε)-approximation of MAX-3SAT is NP-hard. Proof: Any NP-complete problem L ∈ P C P ( O ( log ⁡ ( n ) ) , O ( 1 ) ) {\displaystyle L\in {\mathsf {PCP}}(O(\log(n)),O(1))} by the PCP theorem. For x ∈ L, a 3-CNF formula Ψx is constructed so that x ∈ L ⇒ Ψx is satisfiable x ∉ L ⇒ no more than (1-ε)m clauses of Ψx are satisfiable.The Verifier V reads all required bits at once i.e. makes non-adaptive queries. This is valid because the number of queries remains constant.
Rotational diffusion Relation to translational diffusion Rotational_diffusion > Relation to translational diffusion Much like translational diffusion in which particles in one area of high concentration slowly spread position through random walks until they are near-equally distributed over the entire space, in rotational diffusion, over long periods of time the directions which these particles face will spread until they follow a completely random distribution with a near-equal amount facing in all directions. As impacts from surrounding particles rarely, if ever, occur directly in the centre of mass of a 'target' particle, each impact will occur off-centre and as such it is important to note that the same collisions that cause translational diffusion cause rotational diffusion as some of the impact energy is transferred to translational kinetic energy and some is transferred into torque.
Is functions Summary Is_functions The Is functions (also known as data information functions, data inspection functions, or data-testing functions) are a set of functions in Microsoft's Visual Basic 6, Visual Basic for Applications, VBScript, and Visual Basic .NET. Several of them are also provided in Transact-SQL by the .NET Framework Data Provider for Microsoft SQL Server.
Expression proteomics Bioinformatics for proteomics (proteome informatics) Call-map_proteomics > Bioinformatics for proteomics (proteome informatics) Much proteomics data is collected with the help of high throughput technologies such as mass spectrometry and microarray. It would often take weeks or months to analyze the data and perform comparisons by hand. For this reason, biologists and chemists are collaborating with computer scientists and mathematicians to create programs and pipeline to computationally analyze the protein data.
Apoptosis Pathway knock-outs Apoptotic_pathway > Pathway knock-outs Many knock-outs have been made in the apoptosis pathways to test the function of each of the proteins. Several caspases, in addition to APAF1 and FADD, have been mutated to determine the new phenotype. In order to create a tumor necrosis factor (TNF) knockout, an exon containing the nucleotides 3704–5364 was removed from the gene. This exon encodes a portion of the mature TNF domain, as well as the leader sequence, which is a highly conserved region necessary for proper intracellular processing.
SR protein Splicing SR_protein > Function > Splicing Some evidence suggests that selection of the mRNA splicing variant depends upon the relative ratios of SR proteins. SR proteins appear to be redundant.
Bogoliubov transformation Applications Bogoliubov_transformation > Single bosonic mode example > Applications The most prominent application is by Nikolai Bogoliubov himself in the context of superfluidity. Other applications comprise Hamiltonians and excitations in the theory of antiferromagnetism. When calculating quantum field theory in curved space–times the definition of the vacuum changes, and a Bogoliubov transformation between these different vacua is possible. This is used in the derivation of Hawking radiation. Bogoliubov transforms are also used extensively in quantum optics, particularly when working with gaussian unitaries (such as beamsplitters, phase shifters, and squeezing operations).
Idealized greenhouse model Additional bibliography Idealized_greenhouse_model > Additional bibliography ISBN 978-3-527-40503-9. Petty, Grant W. (2006).
Real time locating Errors and accuracy Real-time_locating_system > Errors and accuracy False locationThe measured location may appear entirely faulty. This is a generally result of simple operational models to compensate for the plurality of error sources.
Peer group Summary Peer_group In sociology, a peer group is both a social group and a primary group of people who have similar interests (homophily), age, background, or social status. The members of this group are likely to influence the person's beliefs and behaviour.During adolescence, peer groups tend to face dramatic changes. Adolescents tend to spend more time with their peers and have less adult supervision. Adolescents' communication shifts during this time as well.
Object-capability model Glossary of related terms Object-capability_model > Glossary of related terms object-capability system A computational system that implements principles described in this article. object An object has local state and behavior. An object in this sense is both a subject and an object in the sense used in the access control literature.
Isotopomer 13C-NMR Isotopomer > Use > 13C-NMR Nearly all of the carbon in normal samples of carbon-based chemicals is 12C, with only about 1% abundance of 13C, so there is only about a 1% abundance of the total of the singly-substituted isotopologues, and exponentially smaller amounts of structures having two or more 13C in them. The rare case where two adjacent carbon atoms in a single structure are both 13C causes a detectable coupling effect between them as well as signals for each one itself. The INADEQUATE correlation experiment uses this effect to provide evidence for which carbon atoms in a structure are attached to each other, which can be useful for determining the actual structure of an unknown chemical.
Communicative Constitution of Organizations Activity coordination Communicative_Constitution_of_Organizations > McPhee & Zaug's Four Flows > Activity coordination Activity coordination is a result of the fact that organizations inherently have at least one purpose to which the members' activity is contributing. Often an organization's self-structuring defines the division of labor, work flow sequences, policies, etc. that set the course for activity coordination. The structure is reflexively changing and may not be complete, relevant, fully understood, or free of problems. Therefore, a necessity of communication arises among members to amend and adjust the work process.
Validation set Summary Validation_set In particular, three data sets are commonly used in different stages of the creation of the model: training, validation, and test sets. The model is initially fit on a training data set, which is a set of examples used to fit the parameters (e.g. weights of connections between neurons in artificial neural networks) of the model. The model (e.g. a naive Bayes classifier) is trained on the training data set using a supervised learning method, for example using optimization methods such as gradient descent or stochastic gradient descent.
Ohm's Law History Ohms_Law > History Also, Ohm's brother Martin, a mathematician, was battling the German educational system. These factors hindered the acceptance of Ohm's work, and his work did not become widely accepted until the 1840s. However, Ohm received recognition for his contributions to science well before he died.
Tilting trike Terminology Tilting_trike > Terminology Tilting vehicles may exhibit nearly any combination of the above behaviors, due to any combination of their geometry, mass distribution, suspension characteristics, rider input, or some other active control system. active, passive, and free usually refer to how the tilt angle is controlled, directly or indirectly. "Active" control usually requires some sensor(s), some capacity to calculate a response, such as a feedback controller, and some actuator(s) that require power sources.
Domain theory Motivation and intuition Domain_theory > Motivation and intuition The important step to finding a model for the lambda calculus is to consider only those functions (on such a partially ordered set) that are guaranteed to have least fixed points. The set of these functions, together with an appropriate ordering, is again a "domain" in the sense of the theory. But the restriction to a subset of all available functions has another great benefit: it is possible to obtain domains that contain their own function spaces, i.e. one gets functions that can be applied to themselves.
Non-random segregation of chromosomes Rodents Non-random_segregation_of_chromosomes > Single chromosomes or chromosome pairs > Rodents During meiosis, this mutated chromosome (X*) enters the egg nucleus more frequently than the Y chromosome and is therefore more likely to be transmitted to the offspring. A second example concerns a B chromosome in the Siberian collared lemming Dicrostonyx torquatus. In female meiosis I of this species, unpaired B chromosomes are preferentially assigned to the future egg nucleus and thus accumulate in the inheritance.In Siberian populations of the house mouse, a variant form of chromosome 1 with two insertions occurs.
Income inequality metrics Summary Income_inequality_metrics Income inequality metrics or income distribution metrics are used by social scientists to measure the distribution of income and economic inequality among the participants in a particular economy, such as that of a specific country or of the world in general. While different theories may try to explain how income inequality comes about, income inequality metrics simply provide a system of measurement used to determine the dispersion of incomes. The concept of inequality is distinct from poverty and fairness.
Kalina cycle Summary Kalina_cycle The Kalina cycle, developed by Alexander Kalina, is a thermodynamic process for converting thermal energy into usable mechanical power. It uses a solution of 2 fluids with different boiling points for its working fluid. Since the solution boils over a range of temperatures as in distillation, more of the heat can be extracted from the source than with a pure working fluid. The same applies on the exhaust (condensing) end.
Morphogenesis Cellular basis Nanos_gene > Cellular basis Cell "sorting out" consists of cells moving so as to sort into clusters that maximize contact between cells of the same type. The ability of cells to do this has been proposed to arise from differential cell adhesion by Malcolm Steinberg through his differential adhesion hypothesis. Tissue separation can also occur via more dramatic cellular differentiation events during which epithelial cells become mesenchymal (see Epithelial–mesenchymal transition).
Pyruvate dehydrogenase complex 3D structures Pyruvate_dehydrogenase_complex > External links > 3D structures 16 (1): 104–114. doi:10.1016/j.str.2007.10.024. ISSN 0969-2126. PMC 4807695. PMID 18184588., human full-length and truncated E2 (tE2) cores of PDC, expressed in E. coli
Current densities Total current in materials Electric_current_density > Calculation of current densities in matter > Total current in materials The total current is simply the sum of the free and bound currents:
Resonance Raman spectroscopy Theory Resonance_Raman_spectroscopy > Theory Resonance Raman spectroscopy takes advantage of an increase in the intensity of Raman scattering when the incident photons match the energy of an electronic transition. If the energy of the photon striking the sample is equal or close to that of an electronic transition in the sample, certain Raman-active vibrational modes—those producing nuclear displacement in the same direction as the electronic transition—will exhibit greatly enhanced scattering, up to 106-fold compared to nonresonance Raman. For totally symmetric modes, this increased scattering intensity results from so-called A-term or Franck-Condon scattering, due to the nonzero Franck-Condon overlaps between ground and excited states.
Molar mass constant Summary Molar_mass_constant The molar mass constant, usually denoted by Mu, is a physical constant defined as one twelfth of the molar mass of carbon-12: Mu = M(12C)/12. The molar mass of any element or compound is its relative atomic mass (atomic weight) multiplied by the molar mass constant. The mole and the relative atomic mass were originally defined in the International System of Units (SI) in such a way that the constant was exactly 1 g/mol. That is, the numerical value of the molar mass of an element, in grams per mole of atoms, was equal to its atomic mass relative to the atomic mass constant, mu.
Loudspeaker Efficiency vs. sensitivity Passive_speakers_(audio) > Specifications > Efficiency vs. sensitivity Driver ratings based on the SPL for a given input are called sensitivity ratings and are notionally similar to efficiency. Sensitivity is usually defined as so many decibels at 1 W electrical input, measured at 1 meter (except for headphones), often at a single frequency. The voltage used is often 2.83 VRMS, which is 1 watt into an 8 Ω (nominal) speaker impedance (approximately true for many speaker systems).
Ionic bonds Formation Ionic_interaction > Formation In general, the reaction is exothermic, but, e.g., the formation of mercuric oxide (HgO) is endothermic. The charge of the resulting ions is a major factor in the strength of ionic bonding, e.g. a salt C+A− is held together by electrostatic forces roughly four times weaker than C2+A2− according to Coulomb's law, where C and A represent a generic cation and anion respectively. The sizes of the ions and the particular packing of the lattice are ignored in this rather simplistic argument.
Designer babies CRISPR/Cas9 Designer_baby > Human germline engineering > CRISPR/Cas9 The CRISPR/Cas9 system (CRISPR – Clustered Regularly Interspaced Short Palindromic Repeats, Cas9 – CRISPR-associated protein 9) is a genome editing technology based on the bacterial antiviral CRISPR/Cas system. The bacterial system has evolved to recognize viral nucleic acid sequences and cut these sequences upon recognition, damaging infecting viruses. The gene editing technology uses a simplified version of this process, manipulating the components of the bacterial system to allow location-specific gene editing.The CRISPR/Cas9 system broadly consists of two major components – the Cas9 nuclease and a guide RNA (gRNA). The gRNA contains a Cas-binding sequence and a ~20 nucleotide spacer sequence, which is specific and complementary to the target sequence on the DNA of interest.
Geometric rigidity The rigidity matrix as a linear transformation Geometric_rigidity > The rigidity matrix as a linear transformation The information in this section can be found in. The rigidity matrix can be viewed as a linear transformation from R d \| V \| {\displaystyle \mathbb {R} ^{d\|V\|}} to R \| E \| {\displaystyle \mathbb {R} ^{\|E\|}} . The domain of this transformation is the set of 1 × d \| V \| {\displaystyle 1\times d\|V\|} column vectors, called velocity or displacements vectors, denoted by p ′ {\displaystyle p'} , and the image is the set of 1 × \| E \| {\displaystyle 1\times \|E\|} edge distortion vectors, denoted by e ′ {\displaystyle e'} . The entries of the vector p ′ {\displaystyle p'} are velocities assigned to the vertices of a framework ( G , p ) {\displaystyle (G,p)} , and the equation R ( G , p ) p ′ = e ′ {\displaystyle R(G,p)p'=e'} describes how the edges are compressed or stretched as a result of these velocities.
Water clock India Water_clock > Regional development > India At Nalanda, a Buddhist university, four hour intervals were measured by a water clock, which consisted of a similar copper bowl holding two large floats in a larger bowl filled with water. The bowl was filled with water from a small hole at its bottom; it sank when completely filled and was marked by the beating of a drum at daytime. The amount of water added varied with the seasons, and the clock was operated by students at the university.Descriptions of similar water clocks are also given in the Pañca Siddhāntikā by the polymath Varāhamihira (6th century AD), which adds further detail to the account given in the Sürya Siddhānta. Further descriptions are recorded in the Brāhmasphuṭa Siddhānta, by the mathematician Brahmagupta (7th century AD). A detailed description with measurements is also recorded by the astronomer Lalla (8th century AD), who describes the ghati as a hemispherical copper vessel with a hole that is fully filled after one nadika.
Complex Adaptive System Overview Complex_Adaptive_System > Overview CAS can be hierarchical, but more often exhibit aspects of "self-organization".The term complex adaptive system was coined in 1968 by sociologist Walter F. Buckley who proposed a model of cultural evolution which regards psychological and socio-cultural systems as analogous with biological species. In the modern context, complex adaptive system is sometimes linked to memetics, or proposed as a reformulation of memetics. Michael D. Cohen and Robert Axelrod however argue the approach is not social Darwinism or sociobiology because, even though the concepts of variation, interaction and selection can be applied to modelling 'populations of business strategies', for example, the detailed evolutionary mechanisms are often distinctly unbiological. As such, complex adaptive system is more similar to Richard Dawkins's idea of replicators.
Bohlen–Pierce scale Timbre and the tritave Bohlen-Pierce_scale > Timbre and the tritave 3:1 serves as the fundamental harmonic ratio, replacing the diatonic scale's 2:1 (the octave). () This interval is a perfect twelfth in diatonic nomenclature (perfect fifth when reduced by an octave), but as this terminology is based on step sizes and functions not used in the BP scale, it is often called by a new name, tritave (), in BP contexts, referring to its role as a pseudooctave, and using the prefix "tri-" (three) to distinguish it from the octave. In conventional scales, if a given pitch is part of the system, then all pitches one or more octaves higher or lower also are part of the system and, furthermore, are considered equivalent. In the BP scale, if a given pitch is present, then none of the pitches one or more octaves higher or lower are present, but all pitches one or more tritaves higher or lower are part of the system and are considered equivalent.
Experimental confirmation Hypothesis Scientific_studies > Overview > Process > Hypothesis A hypothesis is a conjecture, based on knowledge obtained while formulating the question, that may explain any given behavior. The hypothesis might be very specific; for example, Einstein's equivalence principle or Francis Crick's "DNA makes RNA makes protein", or it might be broad; for example, "unknown species of life dwell in the unexplored depths of the oceans". See § Hypothesis development A statistical hypothesis is a conjecture about a given statistical population. For example, the population might be people with a particular disease.
NetBeans NetBeans Profiler NetBeans > Integrated modules > NetBeans Profiler One of those techniques is dynamic bytecode instrumentation, which is particularly useful for profiling large Java applications. Using dynamic bytecode instrumentation and additional algorithms, the NetBeans Profiler is able to obtain runtime information on applications that are too large or complex for other profilers. NetBeans also support Profiling Points that let you profile precise points of execution and measure execution time.
GQL Graph Query Language Querying with visual path patterns Graph_Query_Language > Extending existing graph query languages > Cypher > Querying with visual path patterns Queries are therefore able to first project a sub-graph of the graph input into the query, and then extract the data values associated with that subgraph. Data values can also be processed by functions, including aggregation functions, leading to the projection of computed values which render the information held in the projected graph in various ways. Following the lead of G-CORE and Morpheus, GQL aims to project the sub-graphs defined by matching patterns (and graphs then computed over those sub-graphs) as new graphs to be returned by a query. Patterns of this kind have become pervasive in property graph query languages, and are the basis for the advanced pattern sub-language being defined in SQL/PGQ, which is likely to become a subset of the GQL language. Cypher also uses patterns for insertion and modification clauses ( CREATE and MERGE ), and proposals have been made in the GQL project for collecting node and edge patterns to describe graph types.
Martinus Beijerinck Scientific career Martinus_Beijerinck > Life > Scientific career Bacteria perform nitrogen fixation, dwelling inside root nodules of certain plants (legumes). In addition to having discovered a biochemical reaction vital to soil fertility and agriculture, Beijerinck revealed this archetypical example of symbiosis between plants and bacteria. Beijerinck discovered the phenomenon of bacterial sulfate reduction, a form of anaerobic respiration.
Memory disorder Parkinson's disease Memory_disorder > In alphabetical order > Parkinson's disease Specific parkinsonian symptoms, bradykinesia and rigidity, have been shown to be associated with decline of cognitive function. The underlying neuropathological disturbance in PD involves selective deterioration of subcortical structures, and the executive dysfunction in PD, especially in processes that involve working memory. This has been shown to be related to decreased activation in the basal ganglia and frontal cortex.
Communication theory Information Theory Communication_theory > Communication Theory by Perspective/Subdiscipline > Information Theory Alan Turing in 1940 used similar ideas as part of the statistical analysis of the breaking of the German second world war Enigma ciphers. The main landmark event that opened the way to the development of the information theory form of communication theory was the publication of an article by Claude Shannon (1916–2001) in the Bell System Technical Journal in July and October 1948 under the title "A Mathematical Theory of Communication". Shannon focused on the problem of how best to encode the information that a sender wants to transmit.
Mertens-stable equilibrium Summary Mertens-stable_equilibria This solution concept is now called Mertens stability, or just stability. Like other refinements of Nash equilibrium used in game theory stability selects subsets of the set of Nash equilibria that have desirable properties. Stability invokes stronger criteria than other refinements, and thereby ensures that more desirable properties are satisfied.
Shelving buffer Summary Shelving_buffer A shelving buffer is a technique used in computer processors to increase the efficiency of superscalar processors. It allows for multiple instructions to be dispatched at once regardless of the data dependencies between those instructions. This allows for out-of-order execution to occur which increases the throughput of the microprocessor.
Foster's reactance theorem Summary Foster's_reactance_theorem The theorem can be extended to admittances and the encompassing concept of immittances. A consequence of Foster's theorem is that zeros and poles of the reactance must alternate with frequency. Foster used this property to develop two canonical forms for realising these networks.
Adaptive noise cancelling Applications Adaptive_noise_cancelling > Applications The extraction of the remnant recipient pacemaker signal from a heart transplant animal from an ECG which also included the stronger ECG signal of the donor heart. (see proof of concept above) Similarly fetal electrocardiograms are received in the presence of the mother’s stronger ECG and can be extracted using adaptive noise cancelling to reduce the effect of the mother’s ECG. Adaptive noise cancelling has also been used to eliminate patient motion artifacts during general ECG measurements Adaptive noise cancelling techniques can also been used in the context of Active Noise Control to reduce acoustic noise in a physical space Adaptive noise cancelling has also been used in rail surface defect detection.
Comfort cab Safety Comfort_cab > Features > Safety The modern comfort cab design is usually built with a specially reinforced nose. Instead of sheet metal, ⅜-inch-thick steel is employed with additional reinforcement behind the armor. As a moving locomotive cannot maneuver to avoid collisions and frequently cannot stop in time to prevent them, these enhancements serve to protect the crew in the event of a collision with objects smaller than the train itself such as downed trees or stopped automobiles. In addition, the windows of the cab meet Federal Railroad Administration Regulations Part 223, which states that windows must withstand the impact of a .22 caliber bullet or a cinder block.
Polyelectrolyte adsorption Poor solvent Polyelectrolyte_adsorption > Effects of contents and quality of the solution > Poor solvent In a poor solvent, the solvent molecules interact poorly or unfavorably with the charged portions of the polyelectrolyte. The inability of the solvent to effectively screen the charges between repeat units causes the polymer to assume a looser conformation due to electrostatic repulsion of its repeat units. These interactions allow for the polymer to be more uniformly deposited onto the substrate.

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