The objective of this study was to develop a new kinetic model to describe the isothermal growth of microorganisms. The new model was tested with Listeria monocytogenes in tryptic soy broth and frankfurters, and compared with 2 commonly used models-Baranyi and modified Gompertz models. Bias factor (BF), accuracy factor (AF), and root mean square errors (RMSE) were used to evaluate the 3 models....

UNLABELLED We propose a model, based on the Gompertz equation, to describe the growth of yeasts colonies on agar medium. This model presents several advantages: (i) one equation describes the colony growth, which previously needed two separate ones (linear increase of radius and of the squared radius); (ii) a similar equation can be applied to total and viable cells, colony area or colony radiu...

The models relating the intensity of perception to the stimulus are of great importance in sensorial analysis and practical applications. For example, in olfactometry they have been employed to determine: the odour threshold and suprathreshold, hedonic scale assessment and the degree of appreciation. The perceived intensity of a stimuli should be expressed in the form of function depending on a...

In this study, 2 alternative growth functions, the Lomolino and the extreme value function (EVF), are introduced and their ability to predict body, carcass, and breast weight in ducks evaluated. A comparative study was carried out of these equations with standard growth functions: Gompertz, exponential, Richards, and generalized Michaelis-Menten. Goodness of fit of the functions was evaluated u...

Abstract In this paper we prove that in a survivorship group, the force of mortality of the group must follow Gompertz’s law provided that, for the joint-life status of every two lives, one can find a single-life status whose time-until-death’s distribution equals that of the joint-life status. Therefore, the assumption that the force of mortality follows Gompertz’s law is the necessary and suf...

This paper lays the foundation for the theoretical analysis of individual retirement savings by solving a life-cycle model suggested by Yaari (1965) with intertemporal consumption decisions, time-varying income, an uncertain lifetime, and borrowing constraints. A solution is derived both for the general case and for the case with power utility and Gompertz mortality, which leads to closed-form ...

Association or linkage studies involving control and long-lived populations provide information on genes that influence longevity. However, the relationship between allele-specific differences in survival and the genetic structure of aging cohorts remains unclear. We model a heterogeneous cohort comprising several genotypes differing in age-specific mortality. In its most general form, without ...

Neural networks offer an alternative to regression analysis for biological growth modeling. Very little research has been conducted to model animal growth using artificial neural networks. Twenty-five male chicks (Ross x Ross 308) were raised in an environmental chamber. Body weights were determined daily and feed and water were provided ad libitum. The birds were fed a starter diet (23% CP and...