In mathematics, the nimbers, also called Grundy numbers, are introduced in combinatorial game theory, where they are defined as the values of heaps in the game Nim. The nimbers are the ordinal numbers endowed with nimber addition and nimber multiplication, which are distinct from ordinal addition and ordinal multiplication.
In probability theory and statistics, the beta distribution is a family of continuous probability distributions defined on the interval [0, 1] parameterized by two positive shape parameters, denoted by α and β, that appear as exponents of the random variable and control the shape of the distribution. The generalization to multiple variables is called a Dirichlet distribution.
In probability theory and statistics, the gamma distribution is a two-parameter family of continuous probability distributions. The exponential distribution, Erlang distribution, and chi-square distribution are special cases of the gamma distribution. There are two different parameterizations in common use:
- With a shape parameter k and a scale parameter θ.
- With a shape parameter α = k and an inverse scale parameter β = 1/θ, called a rate parameter.
In mathematics, a root system is a configuration of vectors in a Euclidean space satisfying certain geometrical properties. The concept is fundamental in the theory of Lie groups and Lie algebras, especially the classification and representation theory of semisimple Lie algebras. Since Lie groups and Lie algebras have become important in many parts of mathematics during the twentieth century, the apparently special nature of root systems belies the number of areas in which they are applied. Further, the classification scheme for root systems, by Dynkin diagrams, occurs in parts of mathematics with no overt connection to Lie theory. Finally, root systems are important for their own sake, as in spectral graph theory.
Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral nervous system, muscle, and many other tissues of many organisms. At the neuromuscular junction they are the primary receptor in muscle for motor nerve-muscle communication that controls muscle contraction. In the peripheral nervous system: (1) they transmit outgoing signals from the presynaptic to the postsynaptic cells within the sympathetic and parasympathetic nervous system, and (2) they are the receptors found on skeletal muscle that receive acetylcholine released to signal for muscular contraction. In the immune system, nAChRs regulate inflammatory processes and signal through distinct intracellular pathways. In insects, the cholinergic system is limited to the central nervous system.
In Bayesian probability theory, if the posterior distributions p(θ | x) are in the same probability distribution family as the prior probability distribution p(θ), the prior and posterior are then called conjugate distributions, and the prior is called a conjugate prior for the likelihood function p(x | θ). For example, the Gaussian family is conjugate to itself with respect to a Gaussian likelihood function: if the likelihood function is Gaussian, choosing a Gaussian prior over the mean will ensure that the posterior distribution is also Gaussian. This means that the Gaussian distribution is a conjugate prior for the likelihood that is also Gaussian. The concept, as well as the term "conjugate prior", were introduced by Howard Raiffa and Robert Schlaifer in their work on Bayesian decision theory. A similar concept had been discovered independently by George Alfred Barnard.
A continuous-time Markov chain (CTMC) is a continuous stochastic process in which, for each state, the process will change state according to an exponential random variable and then move to a different state as specified by the probabilities of a stochastic matrix. An equivalent formulation describes the process as changing state according to the least value of a set of exponential random variables, one for each possible state it can move to, with the parameters determined by the current state.
Methylamphetamine may refer to:
Methoxyphenamine, also known as 2-methoxy-N-methylamphetamine (OMMA), is a β-adrenergic receptor agonist of the amphetamine class used as a bronchodilator.
Phenpromethamine, also known as N,β-dimethylphenethylamine, is a sympathomimetic nasal decongestant of the phenethylamine group. It was previously marketed as a nasal inhaler from 1943 through 1960 but is no longer available. The medication is a stimulant and is currently banned by the World Anti-Doping Agency. It has been detected in dietary supplements in the 2010s.
A serotonin releasing agent (SRA) is a type of drug that induces the release of serotonin into the neuronal synaptic cleft. A selective serotonin releasing agent (SSRA) is an SRA with less significant or no efficacy in producing neurotransmitter efflux at other types of monoamine neurons.
DMPEA can refer to two subclasses of substituted phenethylamines:
The molecular formula C10H15N (molar mass : 149.23 g/mol, exact mass : 149.120449) may refer to:
In set theory, an ordinal number, or ordinal, is one generalization of the concept of a natural number that is used to describe a way to arrange a collection of objects in order, one after another.
4-Methylphenylisobutylamine (4-MAB), also known as 4-methyl-α-ethylphenethylamine, is a stimulant drug of the phenethylamine class.
In computer science, a suffix automaton is an efficient data structure for representing the substring index of a given string which allows the storage, processing, and retrieval of compressed information about all its substrings. The suffix automaton of a string is the smallest directed acyclic graph with a dedicated initial vertex and a set of "final" vertices, such that paths from the initial vertex to final vertices represent the suffixes of the string. Formally speaking, a suffix automaton is defined by the following set of properties:
- Its arcs are tagged with letters;
- none of its nodes have two outgoing arcs tagged with the same letter;
- for every suffix of there exists a path from initial vertex to some final vertex such that the concatenation of letters on the path forms this suffix;
- it has the fewest vertices among all graphs defined by the properties above.
2-Phenyl-3-aminobutane is a stimulant of the phenethylamine class that is closely related to its α-methyl analog Pentorex. It was first synthesized by the German scientists Felix Haffner and Fritz Sommer in 1939 as a stimulant with milder effects, shorter duration, lower toxicity and fewer side effects compared to previously known drugs such as amphetamine.
17α-Ethynyl-3β-androstanediol is a synthetic estrogen and a 17α-substituted derivative of 3β-androstanediol which was never marketed.
This page is based on this
Wikipedia article Text is available under the
CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.
