[Competition and adaptation in community of migrating fish populations].

Within a discrete scheme the process of population migration is set by some non-negative Markov matrix. When studying an appropriate class of competition models, nonlinear methods of the convex analysis (the theory of monotonous operators) proved to be highly effective. For special matrixes (cyclic and perron ones) conditions of steady coexistence and competitor replacement in community have been found.

[Electrophysiological characteristics of animal respiratory muscles after long-term stay at high altitudes].

Experiments were made using rats at different stages of readaptation after long-term stay at high altitudes. Characteristics of bioelectrical activity of respiratory muscles were obtained for the first time, its spectral picture is described in different periods of readaptation.

[Evolutionary stability of biological communities].

Some new schemes have been proposed for evolutionary ecological models, where the variables and the parameters vary simultaneously. These models have low dimensions and high-speed performance. It is studied how periodic changes in the temperature influence the population dynamics and location of the evolutionary stable parameters (i.

[Adaptation of interacting populations to the environmental temperature regime].

The biological process of the passing of individuals from the active to the passive state when unfavourable environmental conditions occur has been formalized. This leads to a universal linear superstructing to nonlinear models of ecosystems. At certain rates of this jump, a stabilization of the oscillation instability is possible, and an increase in population vitality can occur.

[Plastic surgery of postoperative abdominal hernias with polypropylene endoprosthesis].

One hundred and twenty-one patients with postoperative abdominal hernias of different size and location were treated, 103 of them underwent surgery with polypropylene endoprosthesis. Size of hernia was objectively assessed with an original method of X-ray-computed hernioabdominometry. The parameter presents as percentage of relative volume of hernia.

[Evolutionary stability in the dynamics of populations having short reproduction periods].

A special class of models of competition (D-systems) were constructed in which the coefficients of population growth are periodic delta-functions. Effective methods for the analysis of the global dynamics of D-systems were proposed. In the framework of this model system, the problem of the existence of evolutionarily stable parameters, the periods of reproduction of populations in a variable medium, was studied.

[Parameters adaptation in the populations models].

Ecology-evolutionary models of low dimensions were developed on the basis of competitive selection criteria. Dynamics of variables (number of individuals) and the search of evolutionary-stable values of parameters (biological characterictics of populations) were monitored in the suggested models. If the environmental temperature is changing periodically, the average (a) and width (d) of temperature tolerance range appears to be the important parameters.

[The economical and evolutionary aspects of the optimal catch of the fish population].

The natural interpretation of population value (internal cost) is used for the common mathematical problem of population exploitation. It is suggested that the population owner--the state--can use internal costs as a tax on fish caught by holders (fishermen). It turns out that such a tax outline make fisherman to establish an optimal long-term strategy of catch.

[Acoustic analysis of signals in mammals].

Spectral-prosodic characteristics of signals were analyzed synchronously with the main frequency for 32 mammals and one reptile using a KAZ-01 complex sound analyzer. The method of phoneme analysis was adapted for analysis of the signals. The main features of signaling in mammals have been revealed, which differed from those in birds and humans: low frequency range, low fundamental frequency, small number of local maxima, small frequency distance between them, and a significant amount of local maxima with zero energy.

[Comparison of species-specific bird sound signals and human speech sounds].

We carried out a comparative study of spectral-prosodic characteristics of bird vocalization and human speech. Comparison was made between the relative characteristics of the fundamental frequency and spectral maxima. Criteria were formulated for the comparison of bird's signals and human speech.

[Universal reserve constants and selection criteria in the periodically changing environment].

The authors analyse different approaches (geometrical and analytical) to investigate the dynamic of competing populations in changing environment. For the broad range of models a sufficient character of selection is determined: in changing environment one population excludes the others if its productivity is higher with some reserve. In competition models "everybody against everybody" there is a universal reserve constant that is not depended on the number of populations in community.

[Endoscopic removal of isolated gastrinoma of the duodenum after Billroth II gastric resection].

Duodenal carcinoma is a rare disease and is encountered in no more than 10% of cases of the Zollinger-Ellison syndrome. The article discusses a rare case in which an isolated duodenal gastrinoma was removed endoscopically with subsequent recovery from the Zollinger-Ellison syndrome. Study of the serum gastrin concentration with provocative tests allowed the Zollinger-Ellison syndrome to be diagnosed and the radicality of duodenal gastrinoma removal to be controlled.

[Acute peptic lesions of the gastroduodenal mucosa in patients with obstructive jaundice].

Complex study of the gastric acid-producing activity, the condition of the gastroduodenal mucosa, and the serum gastrin concentration in 80 patients with obstructive jaundice showed that the appearance of acute erosive-ulcerative injuries of the mucosa of the gastroduodenal zone depended on the increase of activity of the peptic factor of the gastric medium. Peptic complications occurred in 27.1% of patients with initial normo and hyperacidity and a high level of blood gastrin.