PubMed Health⌕ Search

Biomedical subjects

G S Markman

Publications and source records attributed to G S Markman.

8 recordsLinked to original sources
PubMedDate not supplied

[Spatially heterogeneous distribution of phytoplankton in a model of a regulated population].

With the help of the mathematical model is shown that the existence of the phitoplankton's mechanism of growth-speed regulation by means of excretion to the environment of biologically active substances, may lead to a considerable inhomogenity of it's spatial distribution, that is, patchness. There appears an intensive crowding of phitoplankton with homogenious distribution of nutrients, while some limitations of excretion rate and of dispersion coefficients are taken into account.

Mathematics↗
PubMedDate not supplied

[Initiation of auto-oscillations in a distributed system with multiple equilibria].

Possible alterations in time of population numbers due to abrupt nonuniformity of environmental conditions were shown by a mathematical model. Elimination of borders between the local systems with stable uniform regimes results in the appearance of auto-oscillations of large amplitude in the whole region. The effect is interpreted in terms of the consequences of applying chemicals for pest control, and of chemotherapy influence on the immune system as well.

Animals↗
PubMedDate not supplied

[Stochastic synchronization of biological systems by external periodic factors].

Influence of external periodic factors on auto-scillation model of biological processes was studied. It has been shown that the cycle pairs are initiated from the condensation of trajectories: a stable and unstable cycles, whose period is five-fold higher than the period of external influence. When the oscillation amplitude of external influences increases due to a successive doubling of the periods, the stable regime is transformed into stochastic oscillations.

Mathematics↗
PubMedDate not supplied

[Initiation of auto-oscillation systems of oscillations with the period multiple to the modulation period].

Using a mathematical model of phytoplankton population dynamics as an example, it has been demonstrated that several stable regimes with different regularities branching off from the balance point and from the limiting cycle of a corresponding autonomous system, may appear in the system, while the periodic time dependence of the model parameters is taken into account.

Animals↗
PubMedDate not supplied

[Development of stationary dissipative structures in a unidimensional Turing--Prigogine model].

An approxmimate formula is obtained for critical value of the parameter which determines the appearance of stationary dissipative structure in Turing--Prigogine linear model. This formula is valid when the length of the segment in which the space coordinate varies is sufficiently large. The estimation is obtained which shows the length of the segment under which the effect of boundary condition on the behaviour of the solution in the middle of the segment is negligible.

Models, Theoretical↗