[Mathematical modeling of life history evolution: a brief history and main trends].

A brief history is recounted of the mathematical theory of life history evolution which originates from works by L. Euler, T. Malthus, A.

[Familiarity recognition and recollection: a neural network model].

The capacity of a specially designed neural network for familiarity recognition and recollection has been compared. The recognition is based on calculating some quantity interpreted as the familiarity of a pattern. The familiarity is calculated using a modified Hopfield energy function in which the value of the inner sum is replaced by the sign of this value.

[Cognitive advantages of the third age: a neural network model of brain aging].

We consider a neural network model of age-related cognitive changes in aging brain based on Hopfield network with a sigmoid function of neuron activation. Age is included in the activation function as a parameter in the form of exponential rate denominator, which makes it possible to take into account the weakening of interneuronal links really observed in the aging brain. Analysis of properties of the Lyapunov function associated with the network shows that, with increasing parameter of age, its relief becomes smoother and the number of local minima (network attractors) decreases.

[Memory blocking: facts, problems, and models].

The tip-of-the-tongue state, or memory blocking, has been investigated from the point of view of possibilities of its neural network modeling. The results of neuropsychological and neurobiological studies on memory blocking have been reviewed, and basic problems whose solution could contribute to the comprehension of this phenomenon have been formulated. One of such questions is the existence of a paradoxical discrepancy between the subjective assurance that a pattern is familiar and the impossibility to recollect it fully.

Worldwide variation in life-span sexual dimorphism and sex-specific environmental mortality rates.

In all human populations mean life span of women generally exceeds that of men, but the extent of this sexual dimorphism varies across different regions of the world. Our purpose here is to study, using global demographic and environmental data, the general tendency of this variation and local deviations from it. We used data on male and female life history traits and environmental conditions for 227 countries and autonomous territories; for each country or territory the life-span dimorphism was defined as the difference between mean life spans of women and men.