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Alexander Loskutov

Publications and source records attributed to Alexander Loskutov.

5 recordsLinked to original sources

Intermittency as a universal characteristic of the complete chromosome DNA sequences of eukaryotes: From protozoa to human genomes

Large-scale dynamical properties of complete chromosome DNA sequences of eukaryotes are considered. By the proposed deterministic models with intermittency and symbolic dynamics we describe a wide spectrum of large-scale patterns inherent in these sequences, such as segmental duplications, tandem repeats, and other complex sequence structures. It is shown that the recently discovered gene number balance on the strands is not of random nature, and a complete chromosome DNA sequence exhibits the properties of deterministic chaos.

q-bio.GN

Deceleration mechanism of Fermi acceleration in a time-dependent stadium billiard

The dynamics of a time-dependent stadium-like billiard are studied by a four dimensional nonlinear mapping. We have shown that even without any dissipation, the particle experiences a decrease on its velocity. Such condition is related with a critical resonance velocity, where if the initial velocity has a higher value than the resonant one, we can observe Fermi acceleration, however, if the initial velocity has a initial value smaller than the critical one, the particle is temporarily trapped surrounding the stability islands, in a stickiness regime. We believe that this sticky orbits can act as deceleration mechanism for Fermi Acceleration.

nlin.CD

Suppression of Complex Spiral--Wave Activity in an Ionic Model of Cardiac Tissue by Weak Local Stimulations

On the basis of a quite realistic ionic Fenton--Karma model of the cardiac tissue we consider the problem of defibrillation by a local weak forcing. In contrast to other systems, this model accurately reproduces the most essential mesoscopic properties of the cardiac activity. It is shown that suppression of spiral--wave turbulent dynamics in the heart tissue may be realized by a low-voltage local non-feedback electrical stimulation of monophasic and biphasic shapes. After stabilization the medium goes to a spatially homogeneous steady state.

nlin.CD

A model of cardiac tissue as a conductive system with interacting pacemakers and refractory time

A model of the heart tissue as a conductive system with two interacting pacemakers and a refractory time, is proposed. In the parametric space of the model the phase locking areas are investigated in detail. Obtained results allow us to predict the behaviour of excitable systems with two pacemakers depending on the type and intensity of their interaction and the initial phase. Comparison of the described phenomena with intrinsic pathologies of cardiac rhythms is presented.

nlin.CD

Chaotic time-dependent billiards

A billiard in the form of a stadium with periodically perturbed boundary is considered. Two types of such billiards are studied: stadium with strong chaotic properties and a near-rectangle billiard. Phase portraits of such billiards are investigated. In the phase plane areas corresponding to decrease and increase of the velocity of billiard particles are found. Average velocities of the particle ensemble as functions of the number of collisions are obtained.

nlin.CD