The objective of this study was to investigate the growth rate of Chlorella vulgaris for CO2 biofixation and biomass production. Six mathematical growth models (Logistic, Gompertz, modified Gompertz, Baranyi, Morgan and Richards) were used to evaluate the biomass productivity in continuous processes and to predict the following parameters of cell growth: lag phase duration (λ), maximum specific...

A kinetic study was conducted to investigate the growth of Escherichia coli O157:H7 in mechanically-tenderized beef meat (MTBM) inoculated and internalized with a cocktail of 5 rifampicin-resistant (Rif(r)) or 3 arbitrarily selected wild-type strains of the bacteria. The storage was conducted at 5, 10, 15, 20, 25, and 37 degrees C. No growth was observed at 5 degrees C and the growth was minima...

inflated at the tail of the survivorship distribution, but whether the Gompertz model fits actual observations better than alternative models of mortality. We found that a two-stage Gompertz model, with almost no increase in mortality rate at older ages, fits the observed data significantly better than a simple single-stage Gompertz model (2). Model fits were obtained by maximum likelihood meth...

Pandora neoaphidis transmission was monitored within progeny colonies initiated by infected Myzus periscae alates individually flown for 1 to 5 h. Mycosis progress in the colonies was well fitted (r2= 0.97) to a modified logistic or Gompertz model that included their flight distance, postflight survival time, premycosis fecundity, and primary infection rate as influential variables.

Description streg performs maximum likelihood estimation for parametric regression survival-time models. streg can be used with singleor multiple-record or singleor multiple-failure st data. Survival models currently supported are exponential, Weibull, Gompertz, lognormal, loglogistic, and generalized gamma. Parametric frailty models and shared-frailty models are also fit using streg. Also see ...

The Gompertz model is the long-time well-known mathematical model of exponential expression among mortality models in the literature that are used to describe mortality and survival data of a population. The death rate of the “probacent” model developed by the author based on animal experiments, clinical applications and mathematical reasoning was applied to predict age-specific death rates in ...

Impedance microbiology is a method that enables tracing microbial growth by measuring the change in the electrical conductivity. Different systems, able to perform this measurement, are available in commerce and are commonly used for food control analysis by mean of measuring a point of the impedance curve, defined "time of detection." With this work we wanted to find an objective way to interp...

Success of pig production depends on maximizing return over feed costs and addressing potential nutrient pollution to the environment. Mathematical modeling has been used to describe many important aspects of inputs and outputs of pork production. This study was undertaken to compare 4 mathematical functions for the best fit in terms of describing specific data sets on pig growth and, in a sepa...

Reliability theory is a general theory about systems failure. It allows researchers to predict the age-related failure kinetics for a system of given architecture (reliability structure) and given reliability of its components. Reliability theory predicts that even those systems that are entirely composed of non-aging elements (with a constant failure rate) will nevertheless deteriorate (fail m...

Despite internal complexity, tumor growth kinetics follow relatively simple laws that can be expressed as mathematical models. To explore this further, quantitative analysis of the most classical of these were performed. The models were assessed against data from two in vivo experimental systems: an ectopic syngeneic tumor (Lewis lung carcinoma) and an orthotopically xenografted human breast ca...