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Growth Curves
Growth curve can refer to: * Growth curve (statistics), an empirical model of the evolution of a quantity over time. * Growth curve (biology), a statistical growth curve used to model a biological quantity. * Curve of growth (astronomy), the relation between the equivalent width and the optical depth. {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Curve (statistics)
The growth curve model in statistics is a specific multivariate linear model, also known as GMANOVA (Generalized Multivariate Analysis-Of-Variance). It generalizes MANOVA by allowing post-matrices, as seen in the definition. Definition Growth curve model: Let X be a ''p''×''n'' random matrix corresponding to the observations, A a ''p''×''q'' within design matrix with ''q'' ≤ ''p'', B a ''q''×''k'' parameter matrix, C a ''k''×''n'' between individual design matrix with rank(''C'') + ''p'' ≤ ''n'' and let Σ be a positive-definite ''p''×''p'' matrix. Then : X=ABC+\Sigma^E defines the growth curve model, where A and C are known, B and Σ are unknown, and E is a random matrix distributed as ''N''''p'',''n''(0,''I''''p'',''n''). This differs from standard MANOVA by the addition of C, a "postmatrix". History Many writers have considered the growth curve analysis, among them Wishart (1938), Box (1950) and Rao (1958). Potthoff and Roy in 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Curve (biology)
A growth curve is an empirical model of the evolution of a quantity over time. Growth curves are widely used in biology for quantities such as population size or biomass (in population ecology and demography, for population growth analysis), individual body height or biomass (in physiology, for growth analysis of individuals). Values for the measured property Bacterial growth In this example (Figure 1, see Lac operon for details) the number of bacteria present in a nutrient-containing broth was measured during the course of an 8-hour cell growth experiment. The observed pattern of bacterial growth is bi-phasic because two different sugars were present, glucose and lactose. The bacteria prefer to consume glucose (Phase I) and only use the lactose (Phase II) after the glucose has been depleted. Analysis of the molecular basis for this bi-phasic growth curve led to the discovery of the basic mechanisms that control gene expression. Cancer cell growth Cancer research is an area o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curve Of Growth
In astronomy, the curve of growth describes the equivalent width of a spectral line as a function of the column density of the material from which the spectral line is observed. Shape The curve of growth describes the dependence of the equivalent width W, which is an effective measure of the strength of a feature in a Emission_spectrum , emission or Absorption_spectroscopy#Absorption_spectrum , absorption spectrum, on the column density N. Because the spectrum of a single spectral line has a Spectral_line_shape , characteristic shape, being broadened by various processes from a pure line, by increasing the optical depth \tau of a medium that either absorbs or emits light, the strength of the feature develops non-trivially. In the case of the combined Spectral_line#Natural_broadening , natural line width, Spectral_line#Pressure_broadening , collisional broadening and thermal Doppler broadening, the spectrum can be described by a Voigt profile and the curve of growth exhibits ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
