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Slobodan Zdravković

Publications and source records attributed to Slobodan Zdravković.

11 recordsLinked to original sources

Double-well potentials and crucial estimations in nonlinear dynamics of microtubules

In the present work, we study the two-component model of microtubules, the basic components of the eukaryotic cytoskeleton. We introduce a couple of estimations, which tremendously simplified the model. The paper is devoted to tangential oscillations of dimers, but we explain that the model can explain the radial oscillations as well. Finally, we study the stability of all solutions of differential equations, describing the dynamics of the microtubules.

physics.bio-ph

Microtubules: dynamics, soliton waves, some roles in the cell

In the present paper we deal with nonlinear dynamics of microtubules (MTs). The structure and role of MTs in cells are explained. One model explaining MT dynamics is explained. Solutions of the crucial nonlinear differential equation depend on used mathematical procedures. Two of them, continuum and semi-discrete approximations, are explained. Finally, these solutions are shown and discussed. They are solitonic waves. Three different kinds of them are known in the moment. They are kink solitons, breathers and bell-type solitons.

physics.bio-ph

Stability analysis of solutions in the helicoidal Peyrard-Bishop model of DNA molecule

We use the helicoidal Peyrard-Bishop model of DNA in the current work. We solve a dynamical equation of motion using a continuum approximation, resulting in kink-solitary waves that travel along the chain. We demonstrate that, whereas supersonic kink solitons are not stable, subsonic ones are. Moreover, we demonstrate the importance of viscosity by showing that no wave is stable in the absence of viscosity.

physics.bio-ph

Two-component model of a microtubule in a semi-discrete approximation

In the present work, we study the nonlinear dynamics of a microtubule, an important part of the cytoskeleton. We use a two-component model of the relevant system. A crucial nonlinear differential equation is solved with semi-discrete approximation, yielding some localised modulated solitary waves called the breathers. A detailed estimation of the existing parameters is provided. The numerical investigation shows that the solutions are robust only if the carrier velocity of the breather wave is higher than its envelope velocity. That disproves the previously accepted solutions based on the equality of these velocities.

physics.bio-ph

Tangential Model of Microtubules

Microtubules (MTs) represent basic components of a cytoskeleton. The present work studies nonlinear dynamics of MTs assuming tangential oscillations of the dimers. We introduce a two component model and show that the dynamics of MTs can be explained in terms of breather solitary waves.

physics.bio-ph

W-potentials in nonlinear biophysics of microtubules

In the present article we investigate the nonlinear dynamics of microtubules, the basic components of the eukaryotic cytoskeleton, and rely on the known general model. A crucial interaction among constitutive particles is modelled using W-potential. Three kinds of this potential are studied, symmetrical and two non-symmetrical. We demonstrate an advantage of the latter ones.

cond-mat.soft

A review of recent studies on nonlinear dynamics of microtubules and DNA

Nonlinear dynamics of two biomolecules is studied. These are a microtubule and DNA molecule. Two mathematical procedures are explained, yielding to three kinds of solitary waves moving through the systems. These waves are kinks, modulated solitary waves called breathers and bell-type solitons.

physics.bio-ph

Employment of Jacobian elliptic functions for solving problems in nonlinear dynamics of microtubules

We show how Jacobian elliptic functions (JEF) can be used to solve ordinary differential equations (ODE) describing nonlinear dynamics of microtubules (MT). We demonstrate that only one of JEFs can be used while the remaining two do not represent the solutions of the crucial differential equation. We show that a kink-type soliton moves along MT. Beside this solution, we discuss a few more that may or may not have physical meaning. Finally, we show what kinds of ODE can be solved using JEFs.

physics.bio-ph

Nonlinear DNA dynamics: nonlinearity versus dispersion

In the present paper we study the impact of dispersion and nonlinearity on DNA dynamics. We rely on the helicoidal Peyrard-Bishop model and use the fact that nonlinear DNA dynamics represents an interplay between nonlinearity and dispersion. We state that a dispersion coefficient and a coefficient of nonlinearity, existing in nonlinear Schrödinger equation, are mutually dependent and show how function and can be obtained. Also, we show how all this can be used to find a possible interval for the parameter describing helicoidal structure of DNA.

physics.bio-ph

Nonlinear dynamics of microtubules - A new model

In the present paper we describe a model of nonlinear dynamics of microtubules (MT) assuming a single longitudinal degree of freedom per tubulin dimer. This is a longitudinal displacement of a dimer at a certain position with respect to the neighbouring one. A nonlinear partial differential equation, describing dimer`s dynamics within MT, is solved both analytically and numerically. It is shown that such nonlinear model can lead to existence of kink solitons moving along the MTs. Internal electrical field strength is calculated using two procedures and a perfect agreement between the results is demonstrated. This enabled estimation of total energy, kink velocity and kink width. To simplify the calculation of the total energy we proved a useful theorem.

physics.bio-ph

Modified extended tanh-function method and nonlinear dynamics of microtubules

We here present a model of nonlinear dynamics of microtubules (MT) in the context of modified extended tanh-function (METHF) method. We rely on the ferroelectric model of MTs published earlier by Satarić et al [1] where the motion of MT subunits is reduced to a single longitudinal degree of freedom per dimer. It is shown that such nonlinear model can lead to existence of kink solitons moving along the MTs. An analytical solution of the basic equation, describing MT dynamics, was compared with the numerical one and a perfect agreement was demonstrated. It is now clearer how the values of the basic parameters of the model, proportional to viscosity and internal electric field, impact MT dynamics. Finally, we offer a possible scenario of how living cells utilize these kinks as signaling tools for regulation of cellular traffic as well as MT depolymerisation.

physics.bio-ph