Gompertz and Weibull functions imply contrasting biological causes of demographic aging. The terms describing increasing mortality with age are multiplicative and additive, respectively, which could result from an increase in the vulnerability of individuals to extrinsic causes in the Gompertz model and the predominance of intrinsic causes at older ages in the Weibull model. Experiments that ma...

an experiment was carried out to estimate growth parameters of broiler chickens received artichoke extract in their drinking water using gompertz non-linear model and to compare gompertz non-linear regression equation and artificial neural network modeling in terms of their ability to predict body weight of broiler chicks at day 42 of age. a total number of 250 one- day- old ross 308 broiler ch...

Abstract In this paper, we report the thermal adaptation of Pseudomonas pseudoalcaligenes, characterized as changes in growth parameters. Six clones derived from a single colony of P. pseudoalcaligenes were cultured in two different temperature regimes for 10 months, with three clones forming the control group, cultured at a constant temperature, and another three clones forming the high-temper...

Based on the mathematical description and biological parameters of three nonlinear growth models (Logistic, Gompertz, Bertalanffy), recent advance curve fitting analysis in goose have been reviewed briefly this paper order to provide some basic information for future research breeding work.

This study was conducted to assess the influence of dietary CP and ME on growth parameters of the French guinea fowl, a meat-type variety. In a 2 x 3 x 3 factorial arrangement, 297 one-day-old French guinea keets (162 females and 135 males) were randomly assigned to experimental diets comprising 3,050, 3,100, and 3,150 kcal of ME/kg, each containing 21, 23, and 25% CP from hatch to 4 wk of age ...

Although the Gompertz formula accurately describes observed mortality distributions over most of their extent, their 'tail' is much longer than that of a Gompertz curve fitted to the whole data set. A simple candidate explanation is that the longest-lived subset of any population will necessarily be enriched in individuals that age more slowly than the average of that population. However, some ...

A stochastic Gompertz model is proposed to study cancer growth with therapy. The reveals that the therapy and environmental fluctuation can control tumor size, but its extinction impossible. Optimal treatment suggested, probability density function elucidated clearly by Fokker-Planck equation.

The purpose of this work was to study the effect of initial pH and yeast Saccharomyces Cerevisiae on biogas production from tofu wastewater (TW). The initial pH was varied in ranging of 5 – 9 in substrate without yeast (T5-T9) and with yeast (TY5-TY9). The results showed that optimum initial pH was 8. The maximum biogas was resulted in T8 (275 mL) and TY8 (421 mL). Yeast addition increased tota...