Variability (other)

	Variability (other) Variability is how spread out or closely clustered a set of data is. Variability may refer to: Biology Genetic variability, a measure of the tendency of individual genotypes in a population to vary from one another Heart rate variability, a physiological phenomenon where the time interval between heart beats varies Human variability, the range of possible values for any measurable characteristic, physical or mental, of human beings Other sciences Climate variability, changes in the components of Earth's climate system and their interactions Spatial variability, when a quantity that is measured at different spatial locations exhibits values that differ across the locations Statistical variability, a measure of dispersion in statistics See also Variability hypothesis, nineteenth century hypothesis that males have a greater range of ability than females Variable (other) Variable renewable energy, a renewable energy source of a fluctuating nature Variance, a specif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Genetic Variability Genetic variability is either the presence of, or the generation of, genetic differences. It is defined as "the formation of individuals differing in genotype, or the presence of genotypically different individuals, in contrast to environmentally induced differences which, as a rule, cause only temporary, nonheritable changes of the phenotype". Genetic variability in a population is important for biodiversity. Causes There are many sources of genetic variability in a population: Homologous recombination is a significant source of variability. During meiosis in sexual organisms, two homologous chromosomes cross over one another and exchange genetic material. The chromosomes then split apart and are ready to contribute to forming an offspring. Recombination is random and is governed by its own set of genes. Being controlled by genes means that recombination is variable in frequency. Immigration, emigration, and translocation – each of these is the movement of an individual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Heart Rate Variability Heart rate variability (HRV) is the physiological phenomenon of variation in the time interval between heartbeats. It is measured by the variation in the beat-to-beat interval. Other terms used include: "cycle length variability", "R–R variability" (where R is a point corresponding to the peak of the QRS complex of the ECG wave; and RR is the interval between successive Rs), and "heart period variability". Methods used to detect beats include: ECG, blood pressure, Ballistocardiography, ballistocardiograms, and the pulse wave signal derived from a photoplethysmograph (PPG). ECG is considered the gold standard for HRV measurement because it provides a direct reflection of cardiac electric activity. Clinical significance Reduced HRV has been shown to be a predictor of mortality after myocardial infarction although others have shown that the information in HRV relevant to acute myocardial infarction survival is fully contained in the mean heart rate. A range of other outcomes an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Human Variability Human variability, or human variation, is the range of possible values for any characteristic, physical or mental, of human beings. Frequently debated areas of variability include cognitive ability, personality, physical appearance (body shape, skin color, etc.) and immunology. Variability is partly heritable and partly acquired ('' nature vs. nurture'' debate). As the human species exhibits sexual dimorphism, many traits show significant variation not just between populations but also between the sexes. Sources of human variability Human variability is attributed to a combination of environmental and genetic sources including: For the genetic variables listed above, few of the traits characterizing human variability are controlled by simple Mendelian inheritance. Most are polygenic or are determined by a complex combination of genetics and environment. Many genetic differences ( polymorphisms) have little effect on health or reproductive success but help to distingui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Climate Variability Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. ''Climate change'' may refer to any time in Earth's history, but the term is now commonly used to describe contemporary climate change. Since the Industrial Revolution, the climate has increasingly been affected by human activities. The climate system receives nearly all of its energy from the sun and radiates energy to outer space. The balance of incoming and outgoing energy and the passage of the energy through the climate system is Earth's energy budget. When the incoming energy is greater than the outgoing energy, Earth's energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and Earth experiences cooling. The energy moving through Earth's climate system finds expression ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Spatial Variability Spatial variability occurs when a quantity that is measured at different spatial locations exhibits values that differ across the locations. Spatial variability can be assessed using spatial descriptive statistics such as the range. Let us suppose that the Rev' z(x) is perfectly known at any point x within the field under study. Then the uncertainty about z(x) is reduced to zero, whereas its spatial variability still exists. Uncertainty is closely related to the amount of spatial variability, but it is also strongly dependent upon sampling. Geostatistical analyses have been strictly performed to study the spatial variability of pesticide sorption and degradation in the field. Webster and Oliver provided a description of geostatistical techniques. Describing uncertainty using geostatistics is not an activity exempt from uncertainty itself as variogram uncertainty may be large and spatial interpolation In numerical analysis, multivariate interpolation is interpolation on functio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Statistical Variability In statistics, dispersion (also called variability, scatter, or spread) is the extent to which a distribution is stretched or squeezed. Common examples of measures of statistical dispersion are the variance, standard deviation, and interquartile range. For instance, when the variance of data in a set is large, the data is widely scattered. On the other hand, when the variance is small, the data in the set is clustered. Dispersion is contrasted with location or central tendency, and together they are the most used properties of distributions. Measures A measure of statistical dispersion is a nonnegative real number that is zero if all the data are the same and increases as the data become more diverse. Most measures of dispersion have the same units as the quantity being measured. In other words, if the measurements are in metres or seconds, so is the measure of dispersion. Examples of dispersion measures include: * Standard deviation * Interquartile range (IQR) * Range * Mean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Variability Hypothesis The variability hypothesis, also known as the greater male variability hypothesis, is the hypothesis that males generally display greater variability in traits than females do. It has often been discussed in relation to human cognitive ability, where some studies appear to show that males are more likely than females to have either very high or very low IQ test scores. In this context, there is controversy over whether such sex-based differences in the variability of intelligence exist, and if so, whether they are caused by genetic differences, environmental conditioning, or a mixture of both. Sex-differences in variability have been observed in many abilities and traits –– including physical, psychological and genetic ones –– across a wide range of sexually dimorphic species. History The notion of greater male variability — at least in respect to physical characteristics — can be traced back to the writings of Charles Darwin. When he expounded his theory of sexual s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Variable (other) Variable may refer to: * Variable (computer science), a symbolic name associated with a value and whose associated value may be changed * Variable (mathematics), a symbol that represents a quantity in a mathematical expression, as used in many sciences * Variable (research), a logical set of attributes * Variable star, a type of astronomical star * "The Variable", an episode of the television series ''Lost'' See also * Variability (other) Variability is how spread out or closely clustered a set of data is. Variability may refer to: Biology Genetic variability, a measure of the tendency of individual genotypes in a population to vary from one another Heart rate variability, a phy ... {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Variable Renewable Energy Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable energy sources, such as dammed hydroelectricity or biomass, or relatively constant sources, such as geothermal power. The use of small amounts of intermittent power has little effect on grid operations. Using larger amounts of intermittent power may require upgrades or even a redesign of the grid infrastructure. Options to absorb large shares of variable energy into the grid include using storage, improved interconnection between different variable sources to smooth out supply, using dispatchable energy sources such as hydroelectricity and having overcapacity, so that sufficient energy is produced even when weather is less favourable. More connections between the energy sector and the building, transport and industrial sectors may also help. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Variance In probability theory and statistics, variance is the expectation of the squared deviation of a random variable from its population mean or sample mean. Variance is a measure of dispersion, meaning it is a measure of how far a set of numbers is spread out from their average value. Variance has a central role in statistics, where some ideas that use it include descriptive statistics, statistical inference, hypothesis testing, goodness of fit, and Monte Carlo sampling. Variance is an important tool in the sciences, where statistical analysis of data is common. The variance is the square of the standard deviation, the second central moment of a distribution, and the covariance of the random variable with itself, and it is often represented by \sigma^2, s^2, \operatorname(X), V(X), or \mathbb(X). An advantage of variance as a measure of dispersion is that it is more amenable to algebraic manipulation than other measures of dispersion such as the expected absolute deviation; for e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]