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Biology subjects

S, V. P.

Publications and source records attributed to S, V. P..

3 recordsLinked to original sources

Modeling Montbeillards height data of a human male

Growth is a dynamic activity of simultaneous biological processes happening at multiple time-scales varying from orders of fractions of a second to several years. Rather than modeling growth with differential equations, this multiple time-scale dynamics is modeled using a simpler algebraic approach that involves continued fraction of the linear time scale. This algebraic approach offers models that are infinitely differentiable like an exponential function but also robust and superposable like linear equations. Thus, unique insights into growth dynamics can be obtained without much need of a calculus background. Growth of bacterial colonies, yeast cultures, Drosophila population, mean individual attributes of Helianthus and rats have already been modeled using this approach. In this work, we extend the modeling procedure to individual human growth using Montbeillards height measurements of his son starting from birth upto almost 18 years of age. Good fits are obtained on the data and growth rates are estimated directly from the model. Thus, this methodology provides generic, flexible, simpler and more interpretable growth models.

developmental biology↗

Fitting multiple bacterial growth data using continued fraction of straight lines.

The growth of a population is the net result of growth and decline in the number of individuals over time. A population grows when the increase in number of individuals is more than the decrease and declines in the opposite scenario. In other words, the growth rate of a population is influenced by two opposing factors, a growth promoting factor and a growth restricting factor. In this work, we estimate growth rates by applying a biological growth model that is based on the continued fraction of straight lines with two parameters a and m. The parameters a and m represent nonlinear i.e. growth restricting and linear i.e. growth promoting parts of the model, respectively. To fit this model, we use a publicly available dataset that exhibits the growth of three different strains of bacteria depending on the concentration gradient of the antibiotic Tetracycline. We also propose a method to automatically estimate growth rates for large-scale applications. Finally, a growth coordinate system with a and m as the axes is used to interpret the estimations. ImportanceIn this work, multiple bacterial growth data has been fitted with a model based on continued fraction of linear growth. The importance of this work lies in the fitting of both growth and death phase with a single model. Rather than modeling growth with differential equations, this model uses algebraic expressions. Therefore, the growth rates are obtained directly from these expressions after fitting. Several of these models can be superposed, and more flexible fits can be obtained based on requirements. There are two parameters that play key roles in fitting. Their values can be expressed on planar plots which are useful to compare multiple growth data. Thus, this methodology provides simpler, generic, flexible and more interpretable growth models.

microbiology↗

A Biological Growth Model using Continued Fraction of Straight Lines

S-shaped curves are ubiquitous in biology especially when it comes to growth of a population or even an individual. Growth models such as the classical Verhulst-Pearl logistic growth equation and its extensions effectively model such S-shaped growth curves. Most of these models are parametrised by three or more parameters. In this work, continued fraction of straight lines has been applied to model S-shaped curves of biological growth through the use of only two parameters a and m. Here, m is the maximum growth rate and a is the parameter restricting the growth rate. The parameters a and m help to better interpret the data when compared to the logistic growth model since m represents factors promoting growth while a represents the constraints on growth. This model is effective for modeling both population as well as individual growth, especially around the phase of rapid growth.

ecology↗