A fractional factorial design was used to measure the effects and interactions of temperature (5, 12, 19 degrees C), pH (4.5-8.5), sodium chloride (0.5-5%) and sodium nitrite (0-200 micrograms/ml) on the aerobic growth of Y. enterocolitica in brain heart infusion broth. Growth curves were modeled by fitting plate count data to the Gompertz equation. Quadratic models of natural logarithm transfo...

Kinetic models for bioethanol production from waste sorghum leaves by Saccharomyces cerevisiae BY4743 are presented. Fermentation processes were carried out at varied initial glucose concentrations (12.5–30.0 g/L). Experimental data on cell growth and substrate utilisation fit the Monod kinetic model with a coefficient of determination (R2) of 0.95. A maximum specific growth rate (μmax) and Mon...

Thermal inactivation kinetics of Listeria innocua CECT 910 inoculated in a vegetable beverage at three pH conditions (4.25, 4.75, and 5.20), four levels of temperature (50, 55, 60, 65℃), and different treatment times (0-75 min) were obtained. Survival curves did not follow a log-linear relationship and consequently were fitted to various mathematical models: Weibull, Geeraerd, Cerf with shoulde...

A new logistic model for bacterial growth was developed in this study. The model is based on a logistic model, which is often applied for biological and ecological population kinetics. The new model is described by a differential equation and contains an additional term for suppression of the growth rate during the lag phase, compared with the original logistic equation. The new model successfu...

Many successful technology forecasting models have been developed but little research has explored the relationship between sample set size and forecast prediction accuracy. This research studies the forecast accuracy of large and small data sets using the simple logisticl, Gompertz, and the extended logistic models. The performance of the models were evaluated using the mean absolute deviation...

Lifespan distributions of populations of quite diverse species such as humans and yeast seem to surprisingly well follow the same empirical Gompertz-Makeham law, which basically predicts an exponential increase of mortality rate with age. This empirical law can for example be grounded in reliability theory when individuals age through the random failure of a number of redundant essential functi...

Results well known in the actuarial community about closed-form expressions to Gompertz and Gompertz-Makeham life expectancies for a person aged x are still being independently rediscovered this day. This note seeks acknowledge previous results expectancies, especially science field, hoping stimulate interdisciplinarity provide background further developments, since derivation of expectancy (an...

Studies in the evolutionary biology of cancer research require good estimates of the intrinsic growth rate of the tumour coefficient. A Gompertzian model is a classical continuous model useful in describing population dynamics; in particular, it is a very efficient mathematical modelto describe tumour growth in humans and animals. The Gompertz survival model of a tumour growth is the interest o...

Salmonella Enteritidis culture was subjected to heat or microwave treatment to obtain bacteria reduction by 4, 5, and 6 log units. Control, heated and microwaving micro-organisms were incubated in a nutrient broth at 10°C for 432 h. Growth-curve parameters were calculated using Gompertz and Baranyi equations. It was found that in most cases untreated salmonellae had a shorter generation time, a...

This study uses the modified Gompertz model and sparse data to analyze the growth rates of different types of computer and Internet-related crimes. The Gompertz model is an appropriate diffusion model because it is capable of modeling two opposite behaviors: (1) acts of attacks and imitation of attacks and (2) deterrence acts to prevent such attacks. In addition, this model can handle sparse da...