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Algebraic data types Explanation Algebraic_data_types > Explanation Algebraic data types are used to represent values that can be one of several types of things. Each type of thing is associated with an identifier called a constructor, which can be viewed as a kind of tag for that kind of data. Each constructor can carry with it a different type of data. A constructor could carry no data (e.g., "Empty" in the example above), or one piece of data (e.g., “Leaf” has one Int value), or multiple pieces of data (e.g., “Node” has two Tree values). |
Ring Learning with Errors Summary Ring_Learning_with_Errors Homomorphic encryption is a form of encryption that allows computation on ciphertext, such as arithmetic on numeric values stored in an encrypted database. RLWE is more properly called learning with errors over rings and is simply the larger learning with errors (LWE) problem specialized to polynomial rings over finite fields. Because of the presumed difficulty of solving the RLWE problem even on a quantum computer, RLWE based cryptography may form the fundamental base for public-key cryptography in the future just as the integer factorization and discrete logarithm problem have served as the base for public key cryptography since the early 1980s. An important feature of basing cryptography on the ring learning with errors problem is the fact that the solution to the RLWE problem can be used to solve a version of the shortest vector problem (SVP) in a lattice (a polynomial-time reduction from this SVP problem to the RLWE problem has been presented). |
Polyfullerene Summary Polyfullerene Polyfullerene is a basic polymer of the C60 monomer group, in which fullerene segments are connected via covalent bonds into a polymeric chain without side or bridging groups. They are called intrinsic polymeric fullerenes, or more often all C60 polymers. Fullerene can be part of a polymer chain in many different ways. Fullerene-containing polymers are divided into following structural categories: Intrinsic polymeric fullerene (homopolymer),Main-chain polymers, Side-chain polymers, Star polymers, Crosslinked polymers, End-caped polymers. |
Splitting the atom Fission chain reaction realized Thermonuclear_fission > History > Fission chain reaction realized However, much was still unknown about fission and chain reaction systems. With the news of fission neutrons from uranium fission, Szilárd immediately understood the possibility of a nuclear chain reaction using uranium. In the summer, Fermi and Szilard proposed the idea of a nuclear reactor (pile) to mediate this process. |
MSSM Higgs mass Gauge-coupling unification Anomaly_mediated_supersymmetry_breaking > Theoretical motivations > Gauge-coupling unification There are two loop corrections and both TeV-scale and GUT-scale threshold corrections that alter this condition on gauge coupling unification, and the results of more extensive calculations reveal that gauge coupling unification occurs to an accuracy of 1%, though this is about 3 standard deviations from the theoretical expectations. This prediction is generally considered as indirect evidence for both the MSSM and SUSY GUTs. Gauge coupling unification does not necessarily imply grand unification and there exist other mechanisms to reproduce gauge coupling unification. However, if superpartners are found in the near future, the apparent success of gauge coupling unification would suggest that a supersymmetric grand unified theory is a promising candidate for high scale physics. |
Long non-coding RNA In regulation of DNA replication timing and chromosome stability Long_non_coding_RNA > Functions > In regulation of DNA replication timing and chromosome stability Asynchronously replicating autosomal RNAs (ASARs) are very long (~200kb) non-coding RNAs that are non-spliced, non-polyadenylated, and are required for normal DNA replication timing and chromosome stability. Deletion of any one of the genetic loci containing ASAR6, ASAR15, or ASAR6-141 results in the same phenotype of delayed replication timing and delayed mitotic condensation (DRT/DMC) of the entire chromosome. DRT/DMC results in chromosomal segregation errors that lead to increased frequency of secondary rearrangements and an unstable chromosome. Similar to Xist, ASARs show random monoallelic expression and exist in asynchronous DNA replication domains. |
Seismic event Summary Seismic_event An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. |
Cell Biology Eukaryotic cell cycle Cellular_Biology > Growth and development > Eukaryotic cell cycle The proliferation of cells is instigated by progenitors. All cells start out in an identical form and can essentially become any type of cells. Cell signaling such as induction can influence nearby cells to determinate the type of cell it will become. |
H3R26me2 Mechanism and function of modification H3R26me2 > Mechanism and function of modification Methylation of H3R26me2 is mediated by CARM1 and is recruited to promoter upon gene activation along with acetyltransferases and activates transcription. When CARM1 is recruited to transcriptional promoters the histone H3 is methylated (H3R17me2 & H3R26me2).H3R26 lies close to H3K27, which is a repressive mark when methylated. There are several ways that H3R26 could change gene expression. |
Long noncoding RNA Functions Telomeric_non-coding_RNAs > Functions Despite accumulating evidence that the majority of long noncoding RNAs in mammals are likely to be functional, only a relatively small proportion has been demonstrated to be biologically relevant. Some lncRNAs have been functionally annotated in LncRNAdb (a database of literature described lncRNAs), with the majority of these being described in humans. Over 2600 human lncRNAs with experimental evidences have been community-curated in LncRNAWiki (a wiki-based, publicly editable and open-content platform for community curation of human lncRNAs). According to the curation of functional mechanisms of lncRNAs based on the literatures, lncRNAs are extensively reported to be involved in ceRNA regulation,transcriptional regulation, and epigenetic regulation. A further large-scale sequencing study provides evidence that many transcripts thought to be lncRNAs may, in fact, be translated into proteins. |
Foreign-language reading aid Human language technologies Language_learning_software > Human language technologies "Programs embodying ASR normally provide a native speaker model that the learner is requested to imitate, but the matching process is not 100% reliable and may result in a learner's perfectly intelligible attempt to pronounce a word or phrase being rejected (Davies 2010: Section 3.4.6 and Section 3.4.7).Parsing is used in a number of ways in CALL. Gupta & Schulze (2010: Section 5) describe how parsing may be used to analyse sentences, presenting the learner with a tree diagram that labels the constituent parts of speech of a sentence and shows the learner how the sentence is structured.Parsing is also used in CALL programs to analyse the learner's input and diagnose errors. Davies (2002) writes: "Discrete error analysis and feedback were a common feature of traditional CALL, and the more sophisticated programs would attempt to analyse the learner's response, pinpoint errors, and branch to help and remedial activities. |
Generalized Verma module Summary Generalized_Verma_module In mathematics, generalized Verma modules are a generalization of a (true) Verma module, and are objects in the representation theory of Lie algebras. They were studied originally by James Lepowsky in the 1970s. The motivation for their study is that their homomorphisms correspond to invariant differential operators over generalized flag manifolds. The study of these operators is an important part of the theory of parabolic geometries. |
The Selfish Gene Summary The_Selfish_Gene The Selfish Gene is a 1976 book on evolution by the ethologist Richard Dawkins, in which the author builds upon the principal theory of George C. Williams's Adaptation and Natural Selection (1966). Dawkins uses the term "selfish gene" as a way of expressing the gene-centred view of evolution (as opposed to the views focused on the organism and the group), popularising ideas developed during the 1960s by W. D. Hamilton and others. From the gene-centred view, it follows that the more two individuals are genetically related, the more sense (at the level of the genes) it makes for them to behave cooperatively with each other. A lineage is expected to evolve to maximise its inclusive fitness—the number of copies of its genes passed on globally (rather than by a particular individual). |
Specific internal energy Description and definition Thermodynamic_energy > Description and definition In such a case, the field is included in the thermodynamic description of the object in the form of an additional external parameter. For practical considerations in thermodynamics or engineering, it is rarely necessary, convenient, nor even possible, to consider all energies belonging to the total intrinsic energy of a sample system, such as the energy given by the equivalence of mass. |
Renewable hydrocarbon fuels via decarboxylation/decarbonylation Catalysts Renewable_fuels_by_decarboxylation > Components > Catalysts However, the method of regeneration preferred in industry use is that of calcination, which would serve to burn off any deposits that may be present. As mentioned above, this reduces the practicality of the use of carbon supported catalysts in industry settings. This makes the use of oxide supported catalysts of particular interest, as some of these catalysts have comparable conversion rates to those of carbon supported catalysts. |
Stack associated to a scheme Abstract stacks Category_fibered_in_groupoids > Definitions > Abstract stacks A category c {\displaystyle c} with a functor to a category C {\displaystyle C} is called a fibered category over C {\displaystyle C} if for any morphism F: X → Y {\displaystyle F:X\to Y} in C {\displaystyle C} and any object y {\displaystyle y} of c {\displaystyle c} with image Y {\displaystyle Y} (under the functor), there is a pullback f: x → y {\displaystyle f:x\to y} of y {\displaystyle y} by F {\displaystyle F} . This means a morphism with image F {\displaystyle F} such that any morphism g: z → y {\displaystyle g:z\to y} with image G = F ∘ H {\displaystyle G=F\circ H} can be factored as g = f ∘ h {\displaystyle g=f\circ h} by a unique morphism h: z → x {\displaystyle h:z\to x} in c {\displaystyle c} such that the functor maps h {\displaystyle h} to H {\displaystyle H} . The element x = F ∗ y {\displaystyle x=F^{*}y} is called the pullback of y {\displaystyle y} along F {\displaystyle F} and is unique up to canonical isomorphism. The category c is called a prestack over a category C with a Grothendieck topology if it is fibered over C and for any object U of C and objects x, y of c with image U, the functor from the over category C/U to sets taking F:V→U to Hom(F*x,F*y) is a sheaf. |
Carbonic gas Regulation of respiration Carbon_dioxide_partial_pressure > Human physiology > Regulation of respiration It is also why flight attendants instruct passengers, in case of loss of cabin pressure, to apply the oxygen mask to themselves first before helping others; otherwise, one risks losing consciousness.The respiratory centers try to maintain an arterial CO2 pressure of 40 mmHg. With intentional hyperventilation, the CO2 content of arterial blood may be lowered to 10–20 mmHg (the oxygen content of the blood is little affected), and the respiratory drive is diminished. This is why one can hold one's breath longer after hyperventilating than without hyperventilating. This carries the risk that unconsciousness may result before the need to breathe becomes overwhelming, which is why hyperventilation is particularly dangerous before free diving. |
Plane stress Stress transformation in plane stress and plane strain Plane_stress > Stress transformation in plane stress and plane strain which is the equation of a circle of radius R {\displaystyle R\,\!} centered at a point with coordinates {\displaystyle \,\!} , called Mohr's circle. |
Analysis of resistive circuits Equivalent circuits Circuit_theory > Equivalent circuits If the sources are constant (DC) sources, the result is a DC circuit. Analysis of a circuit consists of solving for the voltages and currents present in the circuit. The solution principles outlined here also apply to phasor analysis of AC circuits. |
Semantic analysis (computer science) One-pass versus multi-pass compilers Compiler_theory > Compiler construction > One-pass versus multi-pass compilers Classifying compilers by number of passes has its background in the hardware resource limitations of computers. Compiling involves performing much work and early computers did not have enough memory to contain one program that did all of this work. So compilers were split up into smaller programs which each made a pass over the source (or some representation of it) performing some of the required analysis and translations. The ability to compile in a single pass has classically been seen as a benefit because it simplifies the job of writing a compiler and one-pass compilers generally perform compilations faster than multi-pass compilers. |
Second unit Function Second_unit > Function These shots may include things such as close-ups, inserts, cutaways, and establishing shots.In both of these scenarios, the purpose of the second unit is to make the most efficient use of some of the resources that are expensive or scarce in film production: actors' and directors' shooting time, sound stage usage and the cost of sets that may have been built on stages. The work of second units should not be confused with multiple-camera setups, where several cameras film the same scene simultaneously. Large productions may have multiple second units. Although filmmakers may refer to having "three or four units working", each unit would be called an "additional second unit"; usually none would be described as the third or fourth unit. |
High-voltage power supply Linear power supply Electronic_power_supply > Types > DC power supplies > Linear power supply In a linear power supply the AC input voltage passes through a power transformer and is then rectified and filtered to obtain a DC voltage. The filtering reduces the amplitude of AC mains frequency present in the rectifier output and can be as simple as a single capacitor or more complex such as a pi filter. The electric load's tolerance of ripple dictates the minimum amount of filtering that must be provided by the power supply. In some applications, ripple can be entirely ignored. For example, in some battery charging applications, the power supply consists of just a transformer and a diode, with a simple resistor placed at the power supply output to limit the charging current. |
Fast syndrome-based hash Collision resistance and 2-regular null syndrome decoding (2-RNSD) Fast_syndrome-based_hash > Security proof of FSB > Collision resistance and 2-regular null syndrome decoding (2-RNSD) Definition of 2-RNSD: Given w {\displaystyle w} matrices H i {\displaystyle H_{i}} of dimension r × ( n / w ) {\displaystyle r\times (n/w)} and a bit string S {\displaystyle S} of length r {\displaystyle r} such that there exists a set of w ′ {\displaystyle w'} columns, two or zero in each H i {\displaystyle H_{i}} , summing to zero. ( 0 < w ′ < 2 w ) {\displaystyle (0 |
Experimental autoimmune encephalomyelitis Types of EAE Experimental_autoimmune_encephalomyelitis > Types of EAE The archetypical first clinical symptom is weakness of tail tonus that progresses to paralysis of the tail, followed by a progression up the body to affect the hind limbs and finally the forelimbs.However, similar to MS, the disease symptoms reflect the anatomical location of the inflammatory lesions, and may also include emotional lability, sensory loss, optic neuritis, difficulties with coordination and balance (ataxia), and muscle weakness and spasms. Recovery from symptoms can be complete or partial and the time varies with symptoms and disease severity. Depending on the relapse-remission intervals, rats can have up to three bouts of disease within an experimental period. |
Brain Vertebrates Brain > Anatomy > Evolution > Vertebrates Vertebrate brains are surrounded by a system of connective tissue membranes called meninges that separate the skull from the brain. Blood vessels enter the central nervous system through holes in the meningeal layers. The cells in the blood vessel walls are joined tightly to one another, forming the blood–brain barrier, which blocks the passage of many toxins and pathogens (though at the same time blocking antibodies and some drugs, thereby presenting special challenges in treatment of diseases of the brain).Neuroanatomists usually divide the vertebrate brain into six main regions: the telencephalon (cerebral hemispheres), diencephalon (thalamus and hypothalamus), mesencephalon (midbrain), cerebellum, pons, and medulla oblongata. |
Cheque Truncation System For banks Cheque_Truncation_System > Expected benefits > For banks Besides, it reduces operational risk by securing the transmission route. Centralized image archival systems ensure that data storage and retrieval is easy. Reduction of manual tasks leads to reduction of errors. Real-time tracking and visibility of the cheques, less frauds with secured transfer of images to the RBI are other benefits that banks derive from this solution. |
Adiabatic engine Carnot cycle Carnot_heat_engine > Carnot cycle Isentropic (reversible adiabatic) expansion of the gas (isentropic work output). For this step (B to C) the piston and cylinder are assumed to be thermally insulated, thus they neither gain nor lose heat. |
Hash Function Hashing integer data types Hash_algorithm > Hashing integer data types There are several common algorithms for hashing integers. The method giving the best distribution is data-dependent. One of the simplest and most common methods in practice is the modulo division method. |
Holomastigotoides Cytoskeleton Holomastigotoides > Morphology > Cytoskeleton Centrin is a protein found in the cytoskeleton of eukaryotic cells, and plays a role in cell division. In Holomastigotoides cells, there is a high concentration of centrin at the apex of the cell associated with the parabasal fibers, the flagellar bands, and the mitotic spindle. As these are sites where changes in cell shape and movement are initiated, this implies a possible role of centrin in controlling cell shape, direction of movement, and mitosis. Holomastigotoides has been observed to change cell shape and direction of movement constantly. Intracellular calcium ion concentration affects centrin, which in turn can change flagellar band structure and basal body orientation. |
Gas production United States Piped_natural_gas > Energy content, statistics, and pricing > United States Gas meters measure the volume of gas used, and this is converted to therms by multiplying the volume by the energy content of the gas used during that period, which varies slightly over time. The typical annual consumption of a single family residence is 1,000 therms or one Residential Customer Equivalent (RCE). Wholesale transactions are generally done in decatherms (Dth), thousand decatherms (MDth), or million decatherms (MMDth). |
Landau's algorithm Two nested square roots Nested_radicals > Two nested square roots A more general denesting formula could have the form However, Galois theory implies that either the left-hand side belongs to Q ( c ) , {\displaystyle \mathbb {Q} ({\sqrt {c}}),} or it must be obtained by changing the sign of either x , {\displaystyle {\sqrt {x}},} y , {\displaystyle {\sqrt {y}},} or both. In the first case, this means that one can take x = c and γ = δ = 0. |
Semantic ascent Acquiring reference Semantic_ascent > Reference > Acquiring reference This behavior gets rewarded or not, dependent on the situation in which it occurs. Terms are learned by a process of reinforcement and extinction. In this phase, the child is not aware yet of objects, it just reacts to stimulations. |
Specific ventilation Summary Specific_ventilation In respiratory physiology, specific ventilation is defined as the ratio of the volume of gas entering a region of the lung (ΔV) following an inspiration, divided by the end-expiratory volume (V0) of that same lung region: SV = ΔV⁄V0 It is a dimensionless quantity. For the whole human lung, given an indicative tidal volume of 0.6 L and a functional residual capacity of 2.5 L, average SV is of the order of 0.24. The distribution of specific ventilation within the lung can be inferred using Multiple Breath Washout (MBW) experiments or imaging techniques such as Positron Emission Tomography (PET) using 13N, Magnetic Resonance Imaging (MRI) using either hyperpolarized gas (3He, 129Xe) or proton MRI (oxygen enhanced imaging). == References == |
Eyeblink conditioning Lesion studies Eyeblink_conditioning > Critical role of the interposed nucleus > Lesion studies The population of cells critical for EBC appears to be restricted to a ~ 1 mm3 area of dorsolateral anterior INP ipsilateral to the conditioned eye. Lesions to this area of INP result in an inability to acquire eyeblink CRs in naïve animals. Additionally, the permanence of the localized lesion effect is remarkable. In well-trained animals, CRs abolished as a result of lesion are not reacquired, even after extensive training that spans over 8 months (Steinmetz et al., 1992). These results demonstrate that a highly localized region of cerebellum must be intact for CR learning to occur in EBC. |
Royal Engineers bridging and trackway equipment Logistic Support Bridging Royal_Engineers_bridging_and_trackway_equipment > Logistic Support Bridging Logistic Support Bridging (LSB) The LSB is usually constructed with the help of a crane, it provides a larger load capacity than Close Support Bridging or General Support Bridging. One standard unit contains all the components needed to build, launch and dismantle a bridge. The modular design of the equipment means it can be constructed in a large number of different configurations, allowing the system to be used for a wide range of load and spans. The LSB can be deployed on main supply routes to provide new bridges, replace damaged bridges or to upgrade smaller bridges for heavier traffic like tanks and heavy equipment. |
Lebesgue measurable Examples Lebesgue_measure > Examples Any closed interval of real numbers is Lebesgue-measurable, and its Lebesgue measure is the length b − a. The open interval (a, b) has the same measure, since the difference between the two sets consists only of the end points a and b, which each have measure zero. Any Cartesian product of intervals and is Lebesgue-measurable, and its Lebesgue measure is (b − a)(d − c), the area of the corresponding rectangle. Moreover, every Borel set is Lebesgue-measurable. However, there are Lebesgue-measurable sets which are not Borel sets. |
Kelvin temperature Diffusion of thermal energy: black-body radiation Absolute_Temperature > Relationship of temperature, motions, conduction, and thermal energy > Diffusion of thermal energy: black-body radiation Black-body radiation diffuses thermal energy throughout a substance as the photons are absorbed by neighboring atoms, transferring momentum in the process. Black-body photons also easily escape from a substance and can be absorbed by the ambient environment; kinetic energy is lost in the process. As established by the Stefan–Boltzmann law, the intensity of black-body radiation increases as the fourth power of absolute temperature. |
Compound prism Doublet Compound_prism > Doublet The simplest compound prism is a doublet, consisting of two elements in contact, as shown in the figure at right. A ray of light passing through the prism is refracted at the first air-glass interface, again at the interface between the two glasses, and a final time at the exiting glass-air interface. The deviation angle δ {\displaystyle \delta } of the ray is given by the difference in ray angle between the incident ray and the exiting ray: δ = θ 0 − θ 4 {\displaystyle \delta =\theta _{0}-\theta _{4}} . While one can produce direct vision dispersion from doublet prisms, there is typically significant displacement of the beam (shown as a separation between the two dashed horizontal lines in the y direction). |
Sommerfeld–Wilson quantization Shell model (heavier atoms) Bohr_atom > Shell model (heavier atoms) But the repulsions of electrons are taken into account somewhat by the phenomenon of screening. The electrons in outer orbits do not only orbit the nucleus, but they also move around the inner electrons, so the effective charge Z that they feel is reduced by the number of the electrons in the inner orbit. For example, the lithium atom has two electrons in the lowest 1s orbit, and these orbit at Z = 2. |
Rotary wheel blow molding systems Advantages & disadvantages Rotary_wheel_blow_molding_systems > Advantages & disadvantages Other advantages of wheel equipment include: Continuous extrusion Multi-layer coextrusion, with one to seven layers of plastic in the finished part In some applications, In Mold Labeling (IML) can be integrated with little or no cycle time penalty Parison programming capability, for optimization of wall thickness Reduced cycle time on light weight containers, compared to shuttle machinery. Conversely, wheel equipment may suffer cycle time penalties on thick containers Easily implemented view stripe capability Ability to achieve very high outputs from a single machine - lowest "cost per bottle" when compared to other blow molding equipment Higher production efficiencies than most other extrusion blow molding equipment typesDisadvantages: Inability to produce bottles with calibrated neck finishes Downstream trimming required Machines typically dedicated to a narrow range of sizes. Product change can be difficult, especially when downstream trimming changeovers are required. High initial capital investment |
Ring signatures Applications and modifications Ring_signatures > Applications and modifications One of the possible applications can be an offline e-cash system. Traceable ring signature In addition to the previous scheme the public key of the signer is revealed (if they issue more than one signatures under the same private key). An e-voting system can be implemented using this protocol. |
Antigen presenting cells Dendritic cells (DCs) Antigen-presenting_cells > Types and functions > Professional APCs > Dendritic cells (DCs) Dendritic cells have the broadest range of antigen presentation and are necessary for activation of naive T cells. DCs present antigen to both helper and cytotoxic T cells. They can also perform cross-presentation, a process by which they present exogenous antigen on MHC class I molecules to cytotoxic T cells. Cross-presentation allows for the activation of these T cells. |
Gunther Schmidt Editorships Gunther_Schmidt > Editorships Theoretical Foundations of Programming Methodology. Reidel Publishers, ISBN 90-277-1460-6. |
Cook's theorem Contributions Cook–Levin_theorem > Contributions The concept of NP-completeness was developed in the late 1960s and early 1970s in parallel by researchers in North America and the USSR. In 1971, Stephen Cook published his paper "The complexity of theorem proving procedures" in conference proceedings of the newly founded ACM Symposium on Theory of Computing. Richard Karp's subsequent paper, "Reducibility among combinatorial problems", generated renewed interest in Cook's paper by providing a list of 21 NP-complete problems. Cook and Karp each received a Turing Award for this work. |
Measurement Imperial and US customary systems Measurement > Units and systems > Imperial and US customary systems Before SI units were widely adopted around the world, the British systems of English units and later imperial units were used in Britain, the Commonwealth and the United States. The system came to be known as U.S. customary units in the United States and is still in use there and in a few Caribbean countries. These various systems of measurement have at times been called foot-pound-second systems after the Imperial units for length, weight and time even though the tons, hundredweights, gallons, and nautical miles, for example, are different for the U.S. |
Glossary of gene expression terms G Glossary_of_genetics_(0–L) > G genetic recombination Any reassortment or exchange of genetic material within an individual organism or between individuals of the same or different species, especially that which creates genetic variation. In the broadest sense, the term encompasses a diverse class of naturally occurring mechanisms by which nucleic acid sequences are copied or physically transferred into different genetic environments, including homologous recombination during meiosis or mitosis or as a normal part of DNA repair; horizontal gene transfer events such as bacterial conjugation, viral transduction, or transformation; or errors in DNA replication or cell division. Artificial recombination is central to many genetic engineering techniques which produce recombinant DNA. |
Recognition signal Biology Recognition_signal > Biology A recognition signal is also a chemical signal used in biology to signal the end of a section of DNA or RNA during gene duplication in cells. |
Machine learning in bioinformatics Clustering and abundance profiling of BGCs Machine_learning_in_bioinformatics > Applications > Clustering and abundance profiling of BGCs Given their direct relationship to catalytic enzymes, and compounds produced from their encoded pathways, BGCs/GCFs can serve as a proxy to explore the chemical space of microbial secondary metabolism. Cataloging GCFs in sequenced microbial genomes yields an overview of the existing chemical diversity and offers insights into future priorities. Tools such as BiG-SLiCE and BIG-MAP have emerged with the sole purpose of unveiling the importance of BGCs in natural environments. |
Hyperpolarization (physics) Rationale Hyperpolarization_(physics) > Spin-exchange optical pumping > Noble gases and alkali metals > Rationale Because 129Xe has a number of favorable facts in NMR Tech. for working as a contrasting agent even over the other novel gases: Inert xenon does not show chemical reaction like other metals and non-metals because Xenon's electronic configuration is fully occupied as well as it is not radioactive also. To get the solid, liquid state from naturally occurring gaseous state is easy going (figure-8). |
Binary classifier Statistical binary classification Binary_classifier > Statistical binary classification Statistical classification is a problem studied in machine learning. It is a type of supervised learning, a method of machine learning where the categories are predefined, and is used to categorize new probabilistic observations into said categories. When there are only two categories the problem is known as statistical binary classification. Some of the methods commonly used for binary classification are: Decision trees Random forests Bayesian networks Support vector machines Neural networks Logistic regression Probit model Genetic Programming Multi expression programming Linear genetic programmingEach classifier is best in only a select domain based upon the number of observations, the dimensionality of the feature vector, the noise in the data and many other factors. For example, random forests perform better than SVM classifiers for 3D point clouds. |
Deuterium isotope effect Other examples Kinetic_isotope_effect > Case studies > Other examples In this reaction the rate-limiting step is formation of the enolate by deprotonation of the ketone. In this study the KIE is calculated from the reaction rate constants for regular 2,4-dimethyl-3-pentanone and its deuterated isomer by optical density measurements. In asymmetric catalysis, there are rare instances in which a kinetic isotope effect manifests as a significant difference in the enantioselectivity observed for a deuterated substrate compared to a non-deuterated one. One example was reported by Toste and coworkers, in which a deuterated substrate produced an enantioselectivity of 83% ee, compared to 93% ee for the undeuterated substrate. The effect was taken to corroborate additional inter- and intramolecular competition KIE data that suggested cleavage of the C-H/D bond in the enantiodetermining step. |
Temperature Intensive variability Temperature > Thermodynamic approach > Intensive variability In thermodynamic terms, temperature is an intensive variable because it is equal to a differential coefficient of one extensive variable with respect to another, for a given body. It thus has the dimensions of a ratio of two extensive variables. In thermodynamics, two bodies are often considered as connected by contact with a common wall, which has some specific permeability properties. Such specific permeability can be referred to a specific intensive variable. |
Structural optimization Summary Structural_optimization Shape optimization is part of the field of optimal control theory. The typical problem is to find the shape which is optimal in that it minimizes a certain cost functional while satisfying given constraints. In many cases, the functional being solved depends on the solution of a given partial differential equation defined on the variable domain. |
Convolutional layer Distinguishing features Max_pooling > Distinguishing features The architecture thus ensures that the learned "filters" produce the strongest response to a spatially local input pattern. Stacking many such layers leads to nonlinear filters that become increasingly global (i.e. responsive to a larger region of pixel space) so that the network first creates representations of small parts of the input, then from them assembles representations of larger areas. Shared weights: In CNNs, each filter is replicated across the entire visual field. |
PID loop Proportional term Steady-state_error > Controller theory > Proportional term The proportional term produces an output value that is proportional to the current error value. The proportional response can be adjusted by multiplying the error by a constant Kp, called the proportional gain constant. The proportional term is given by P out = K p e ( t ) . {\displaystyle P_{\text{out}}=K_{\text{p}}e(t).} |
Glicksberg fixed-point theorem S = [0,1] Kakutani_fixed-point_theorem > Proof outline > S = [0,1] The proof of Kakutani's theorem is simplest for set-valued functions defined over closed intervals of the real line. However, the proof of this case is instructive since its general strategy can be carried over to the higher-dimensional case as well. Let φ: →2 be a set-valued function on the closed interval which satisfies the conditions of Kakutani's fixed-point theorem. Create a sequence of subdivisions of with adjacent points moving in opposite directions.Let (ai, bi, pi, qi) for i = 0, 1, … be a sequence with the following properties: Thus, the closed intervals form a sequence of subintervals of . |
Glossary of biology L Glossary_of_biology > L linked genes Any set of one or more genes which are sufficiently close together on the same chromosome that they are very unlikely to assort independently and therefore are usually inherited together. lipid A substance that is insoluble in water and soluble in alcohol, ether, and chloroform. Lipids are an important component of living cells. |
Integrate-and-fire model Perfect Integrate-and-fire Biological_neuron_models > Electrical input–output membrane voltage models > Perfect Integrate-and-fire The firing frequency is the inverse of the total inter-spike interval (including dead time). The firing frequency as a function of a constant input current is therefore f ( I ) = I C V t h + t r e f I . {\displaystyle \,\!f(I)={\frac {I}{C_{\mathrm {} }V_{\mathrm {th} }+t_{\mathrm {ref} }I}}.} |
Region inference Implementation Region-based_memory_management > Implementation The overall cost per allocated byte of this scheme is very low; almost all allocations involve only a comparison and an update to the next-free-position pointer. Deallocating a region is a constant-time operation, and is done rarely. Unlike in typical garbage collection systems, there is no need to tag data with its type. |
Long-tail traffic Controlling long-tail traffic Long-tail_traffic > Controlling long-tail traffic For example, when TCP is invoked in HTTP in the context of web client/ server interactions, the size of the file being transported (which is known at the server) is conveyed or made accessible to protocols in the transport layer, including the selection of alternative protocols, for more effective data transport. For short files, which constitute the bulk of connection requests in heavy-tailed file size distributions of web servers, elaborate feedback control may be bypassed in favour of lightweight mechanisms in the spirit of optimistic control, which can result in improved bandwidth utilisation.It was found that the simplest way to control packet traffic is to limit the length of queues. Long queues in the network invariably occur at hosts (entities that can transmit and receive packets). Congestion control can therefore be achieved by reducing the rate of packet production at hosts with long queues.Long-range dependence and its exploitation for traffic control is best suited for flows or connections whose lifetime or connection duration is long lasting. |
English irregular verbs Summary English_irregular_verbs Irregular verbs in Modern English are typically derived from verbs that followed more regular patterns at a previous stage in the history of the language. In particular, many such verbs derive from Germanic strong verbs, which make many of their inflected forms through vowel gradation, as can be observed in Modern English patterns such as sing–sang–sung. The regular verbs, on the other hand, with their preterites and past participles ending in -ed, follow the weak conjugation, which originally involved adding a dental consonant (-t or -d). Nonetheless, there are also many irregular verbs that follow or partially follow the weak conjugation.For information on the conjugation of regular verbs in English, as well as other points concerning verb usage, see English verbs. |
Atony I Atony > I It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as objects such as wood splinters, distinguishing them from the organism's own healthy tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. |
Perceptual control theory The methodology of modeling, and PCT as model Perceptual_control_theory > The methodology of modeling, and PCT as model Further, the variance from perfect control accords well with that observed for living organisms. Perfect control would result in zero effect of the disturbance, but living organisms are not perfect controllers, and the aim of PCT is to model living organisms. When a computer simulation performs with >95% conformity to experimentally measured values, opposing the effect of unpredictable changes in d by generating (nearly) equal and opposite values of qo, it is understood to model the behavior and the internal control-loop structure of the organism.By extension, the elaboration of the theory constitutes a general model of cognitive process and behavior. With every specific model or simulation of behavior that is constructed and tested against observed data, the general model that is presented in the theory is exposed to potential challenge that could call for revision or could lead to refutation. |
Augustin-Jean Fresnel First attempt (1815) Augustin-Jean_Fresnel > Contributions to physical optics > Diffraction > First attempt (1815) Newton evidently thought the fringes were caustics. Thus Arago erred in his belief that the curved paths of the fringes were fundamentally incompatible with the corpuscular theory.Arago's letter went on to request more data on the external fringes. Fresnel complied, until he exhausted his leave and was assigned to Rennes in the département of Ille-et-Vilaine. |
Percussion caps Description Percussion_primer > Description The percussion cap is a small cylinder of copper or brass with one closed end. Inside the closed end is a small amount of a shock-sensitive explosive material such as mercuric fulminate (discovered in 1800; it was the only practical detonator used from about the mid-19th century to the early 20th century). The caplock mechanism consists of a hammer and a nipple (sometimes referred to as a cone). |
Philosophical problem Münchhausen trilemma Philosophical_problem > Epistemology > Münchhausen trilemma In epistemology, the Münchhausen trilemma is a thought experiment intended to demonstrate the theoretical impossibility of proving any truth, even in the fields of logic and mathematics, without appealing to accepted assumptions. If it is asked how any given proposition is known to be true, proof may be provided. The Münchhausen trilemma is that there are only three ways of completing a proof: The circular argument, in which the proof of some proposition presupposes the truth of that very proposition The regressive argument, in which each proof requires a further proof, ad infinitum The dogmatic argument, which rests on accepted precepts which are merely asserted rather than defendedThe trilemma, then, is the decision among the three equally unsatisfying options. Karl Popper's suggestion was to accept the trilemma as unsolvable and work with knowledge by way of conjecture and criticism. |
Behavior of nuclear fuel during a reactor accident Aging of steels Behavior_of_nuclear_fuel_during_a_reactor_accident > Hydriding and waterside corrosion > Aging of steels Irradiation causes the properties of steels to become poorer, for instance SS316 becomes less ductile and less tough. Also creep and stress corrosion cracking become worse. Papers on this effect continue to be published. |
Functional software architecture Unified modeling language Functional_software_architecture > Modeling the business > Unified modeling language UML is a broadly accepted modeling language for the development of software systems and applications. The object-oriented community also tries to use UML for enterprise modeling purposes. They emphasize the use of enterprise objects or business objects from which complex enterprise systems are made. A collection of these objects and corresponding interactions between them can represent a complex business system or process. |
Parameter (machine learning) Self-learning Artificial_Neural_Network > Models > Learning paradigms > Self-learning Self-learning in neural networks was introduced in 1982 along with a neural network capable of self-learning named crossbar adaptive array (CAA). It is a system with only one input, situation s, and only one output, action (or behavior) a. It has neither external advice input nor external reinforcement input from the environment. The CAA computes, in a crossbar fashion, both decisions about actions and emotions (feelings) about encountered situations. The system is driven by the interaction between cognition and emotion. |
Ecological economics Weak versus strong sustainability Forest_carbon_stock > Topics > Weak versus strong sustainability Ecological economics challenges the conventional approach towards natural resources, claiming that it undervalues natural capital by considering it as interchangeable with human-made capital—labor and technology. The impending depletion of natural resources and increase of climate-changing greenhouse gasses should motivate us to examine how political, economic and social policies can benefit from alternative energy. Shifting dependence on fossil fuels with specific interest within just one of the above-mentioned factors easily benefits at least one other. For instance, photo voltaic (or solar) panels have a 15% efficiency when absorbing the sun's energy, but its construction demand has increased 120% within both commercial and residential properties. |
Social simulation Criticisms Social_simulation > Criticisms It is highly difficult and often impractical to attempt to link the findings from the abstract world the simulation creates and our complex society and all of its variation.Researchers working in social simulation might respond that the competing theories from the social sciences are far simpler than those achieved through simulation and therefore suffer the aforementioned drawbacks much more strongly. Theories in some social science tend to be linear models that are not dynamic, and are generally inferred from small laboratory experiments (laboratory tests are most common in psychology but rare in sociology, political science, economics and geography). The behavior of populations of agents under these models is rarely tested or verified against empirical observation. |
Coefficient of restitution Summary Coefficient_of_restitution The coefficient of restitution (COR, also denoted by e), is the ratio of the final to initial relative speed between two objects after they collide. It normally ranges from 0 to 1 where 1 would be a perfectly elastic collision. A perfectly inelastic collision has a coefficient of 0, but a 0 value does not have to be perfectly inelastic. It is measured in the Leeb rebound hardness test, expressed as 1000 times the COR, but it is only a valid COR for the test, not as a universal COR for the material being tested. |
Theoretical total mass-energy Langevin's light-clock Special_Theory_of_Relativity > Consequences derived from the Lorentz transformation > Time dilation > Langevin's light-clock A time interval measured using a single clock which is motionless in a particular reference frame is called a proper time interval.Fig. 4-3B illustrates these same two events from the standpoint of observer B, who is parked by the tracks as the train goes by at a speed of v . {\displaystyle v.} |
Applications of machine learning Data mining Statistical_learning > History and relationships to other fields > Data mining Evaluated with respect to known knowledge, an uninformed (unsupervised) method will easily be outperformed by other supervised methods, while in a typical KDD task, supervised methods cannot be used due to the unavailability of training data. Machine learning also has intimate ties to optimization: many learning problems are formulated as minimization of some loss function on a training set of examples. Loss functions express the discrepancy between the predictions of the model being trained and the actual problem instances (for example, in classification, one wants to assign a label to instances, and models are trained to correctly predict the pre-assigned labels of a set of examples). |
Matrix management Matrix Management 2.0 Matrix_organization > In practice > Scaling back > Matrix Management 2.0 In 2004, despite matrix management having become disfavored, Nokia made an attempt at using a form of it, later described as "matrix management 2.0". The focus is intended to be "leading without authority" so that "no one functional leader is in charge." |
Shadow system Not scalable Shadow_system > Problems > Not scalable Typically, Shadow Data Systems are only used by one or two people. Unless they are developed by experienced programmers, it may be difficult to scale them up to support tens or hundreds of users. |
Bacterial morphological plasticity Bimodal effect Bacterial_morphological_plasticity > Environmental cues > Bimodal effect Multicellular complexes of bacterial cells also change the ability of protist's ingestion. Cells in biofilms or microcolonies are often more resistant to predation. For instance, the swarm cells of Serratia liquefaciens resist predation by its predator, Tetrahymenu. |
Kumpati S. Narendra Research areas Kumpati_S._Narendra > Research areas Nonlinear dynamical systems Artificial neural networks Learning automata Adaptive control Stability theory |
Factorial function Computation Factorial > Properties > Computation Unless optimized for tail recursion, the recursive version takes linear space to store its call stack. However, this model of computation is only suitable when n {\displaystyle n} is small enough to allow n ! {\displaystyle n!} |
NBG set theory Classes and sets Von_Neumann–Bernays–Gödel_set_theory > Axiomatization of NBG > Classes and sets NBG has two types of objects: classes and sets. Intuitively, every set is also a class. There are two ways to axiomatize this. Bernays used many-sorted logic with two sorts: classes and sets. |
Liminality General sources Liminality > General sources Oxford: Clarendon Press, 1989. OED Online Oxford University Press. Accessed June 23, 2007; cf. subliminal. |
Voltage-controlled amplifier Summary Voltage_controlled_amplifier The VCR is one of the numerous interesting circuit elements that can be produced by using a JFET (junction field-effect transistor) with simple biasing. VCRs manufactured in this way can be obtained as discrete devices, e.g. VCR2N. |
List of clinically important bacteria Y List_of_clinically_important_bacteria > Y Yersinia Yersinia enterocolitica Yersinia pestis Yersinia pseudotuberculosis |
Degrees of Freedom Problem (Motor Control) Unifying theories Degrees_of_freedom_problem > Unifying theories Furthermore, most of these theories incorporate some sort of feedback and feed-forward models that the nervous system must utilize. Most of these theories also incorporate some sort of hierarchical neural control scheme, usually with cortical areas at the top and peripheral outputs at the lowest level. However, none of the theories is perfect; the DOF problem will continue to be relevant as long as the nervous system is imperfectly understood. |
Concurrent hash table Contention handling Concurrent_hash_table > Contention handling As with any concurrent data structure, concurrent hash tables suffer from a variety of problems known in the field of concurrent computing as a result of contention. Examples for such are the ABA problem, race conditions, and deadlocks. The extent in which these problems manifest or even occur at all depends on the implementation of the concurrent hash table; specifically which operations the table allows to be run concurrently, as well as its strategies for mitigating problems associated with contention. |
Active Voice Summary Active_Voice Active voice is used in a clause whose subject expresses the main verb's agent. That is, the subject does the verb's designated action. A clause whose agent is marked as grammatical subject is called an active clause. In contrast, a clause in which the subject has the role of patient or theme is named a passive clause, and its verb is expressed in passive voice. Many languages have both an active and a passive voice and this allows for greater flexibility in sentence construction, as either the semantic agent or patient may take the subject syntactic role.In a clause including an impersonal verb, the verb is active in form, but no agent is specified. |
Löwenstein–Jensen medium Composition Löwenstein–Jensen_medium > Composition Presence of glycerol enhances the growth of M. tuberculosis. If the slopes are made on test tubes, they must be stored in cold and used within a month. For cultivation of M. bovis, glycerol is omitted and sodium pyruvate is added. The medium appears green, opaque, and opalescent. |
Fair scheduling Algorithm details Fair_queuing > A byte-weighted fair queuing algorithm > Algorithm details The virtual finish time for a newly queued packet is given by the sum of the virtual start time plus the packet's size. The virtual start time is the maximum between the previous virtual finish time of the same queue and the current instant. With a virtual finishing time of all candidate packets (i.e., the packets at the head of all non-empty flow queues) computed, fair queuing compares the virtual finishing time and selects the minimum one. The packet with the minimum virtual finishing time is transmitted. |
Calendar queue Summary Calendar_queue Such simulators require a good and efficient data structure as time spent on queue management can be significant. The calendar queue (with optimum bucket size) can approach O(1) average performance. Calendar queues are closely related to bucket queues but differ from them in how they are searched and in being dynamically resized. |
Atrial systole Summary Atrial_systole The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next. It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, called systole. After emptying, the heart relaxes and expands to receive another influx of blood returning from the lungs and other systems of the body, before again contracting to pump blood to the lungs and those systems. |
Decadic logarithm Negative logarithms Logarithmus_generalis > Mantissa and characteristic > Negative logarithms Since i is a constant, the mantissa comes from log 10 ( x ) {\displaystyle \log _{10}(x)} , which is constant for given x {\displaystyle x} . This allows a table of logarithms to include only one entry for each mantissa. In the example of 5 × 10i, 0.698 970 (004 336 018 ...) will be listed once indexed by 5 (or 0.5, or 500, etc.). |
Accelerometer Physical principles Free_fall_sensor > Physical principles The effects of this acceleration are indistinguishable from any other acceleration experienced by the instrument so that an accelerometer cannot detect the difference between sitting in a rocket on the launch pad, and being in the same rocket in deep space while it uses its engines to accelerate at 1 g. For similar reasons, an accelerometer will read zero during any type of free fall. This includes use in a coasting spaceship in deep space far from any mass, a spaceship orbiting the Earth, an airplane in a parabolic "zero-g" arc, or any free-fall in a vacuum. Another example is free-fall at a sufficiently high altitude that atmospheric effects can be neglected. |
Accelerando Title Accelerando > Title In Italian, accelerando means "speeding up" and is used as a tempo marking in musical notation. In Stross' novel, it refers to the accelerating rate at which humanity in general, and/or the novel's characters, head towards the technological singularity. |
Discrete measure Summary Discrete_measure In mathematics, more precisely in measure theory, a measure on the real line is called a discrete measure (in respect to the Lebesgue measure) if it is concentrated on an at most countable set. The support need not be a discrete set. Geometrically, a discrete measure (on the real line, with respect to Lebesgue measure) is a collection of point masses. |
Entner–Doudoroff pathway Conversion of glucose to glucose-6-phosphate Entner–Doudoroff_pathway > Catalyzing enzymes > Conversion of glucose to glucose-6-phosphate The first step in ED is phosphorylation of glucose by a family of enzymes called hexokinases to form glucose 6-phosphate (G6P). This reaction consumes ATP, but it acts to keep the glucose concentration low, promoting continuous transport of glucose into the cell through the plasma membrane transporters. In addition, it blocks the glucose from leaking out – the cell lacks transporters for G6P, and free diffusion out of the cell is prevented due to the charged nature of G6P. Glucose may alternatively be formed from the phosphorolysis or hydrolysis of intracellular starch or glycogen. |
Artificial Neural Network Training Neural_network_models > Criticism > Training A common criticism of neural networks, particularly in robotics, is that they require too much training for real-world operation. Potential solutions include randomly shuffling training examples, by using a numerical optimization algorithm that does not take too large steps when changing the network connections following an example, grouping examples in so-called mini-batches and/or introducing a recursive least squares algorithm for CMAC. |
Tropical desert Borax Tropical_desert > Natural resources > Borax Borax is a natural cleaner and freshener, also known as a detergent booster. Boric acid is derived from borax and can be used to manufacture agricultural chemicals such as herbicide and insecticide, It is also used widely in fire retardants, glass, ceramics, water softeners, pharmaceuticals, paint, enamel, cosmetics and coated paper. Billions of dollars of borax has been mined in the northern Mojave Desert since 1881. Borax is also a key ingredient for slime-making, the trend that was popular during the 2016-2017 period. |
Diffractive solar sail Summary Diffractive_solar_sail A diffractive solar sail, or diffractive lightsail, is a type of solar sail which relies on diffraction instead of reflection for its propulsion. Current diffractive sail designs use thin metamaterial films, containing micrometer-size gratings based on polarization or subwavelength refractive structures, causing light to spread out (i.e. diffract) and thereby exert radiation pressure when it passes through them. |
Diving rebreather Carbon dioxide monitoring Gas_extender > Recreational and scientific diving rebreather technological innovations > Carbon dioxide monitoring Hypercapnia has been identified as one of the most prevalent factors in rebreather diving fatalities. This is generally a consequence of scrubber failure to remove carbon dioxide as fast as it is produced, which may be caused by any one or a combination of spent, wet, or inadequately packed, absorbent material, incorrectly designed or assembled canisters, mismatch of absorbent and canister design, or absorbent used beyond its operational range. Higher carbon dioxide partial pressure in the loop leads to higher levels of carbon dioxide in the blood and tissue, which can have a range of symptoms including respiratory distress, increased susceptibility to CNS oxygen toxicity, disorientation, and loss of consciousness.Most rebreather designs have relied on very conservative time-based limits for absorbent duration based on experimental testing, using cold conditions and high workloads and high depth pressures. The usually unnecessarily high conservatism encourages divers to stretch the absorbent duration, which works well enough until it doesn't, often without warning, which can have serious consequences. |
Magnetorheological fluid Material behavior Magnetorheological_fluid > Material behavior To understand and predict the behavior of the MR fluid it is necessary to model the fluid mathematically, a task slightly complicated by the varying material properties (such as yield stress). As mentioned above, smart fluids are such that they have a low viscosity in the absence of an applied magnetic field, but become quasi-solid with the application of such a field. In the case of MR fluids (and ER), the fluid actually assumes properties comparable to a solid when in the activated ("on") state, up until a point of yield (the shear stress above which shearing occurs). This yield stress (commonly referred to as apparent yield stress) is dependent on the magnetic field applied to the fluid, but will reach a maximum point after which increases in magnetic flux density have no further effect, as the fluid is then magnetically saturated. |
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