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T. Biben

Publications and source records attributed to T. Biben.

4 recordsLinked to original sources

A link between ECM plasticity and synaptic morphological evolution

We made a link between Extra Cellular Matrix (ECM) plasticity and the morphologi cal changes in synapses after synaptic excitation. A recent study by Zhang et al \cite{zhang} showed tha t transmembrane voltage causes movement of the cell membrane. Here we will study the relation between th e mechanical properties of collagen which is the major component of the ECM and synaptic morphological c hanges in relation with the theory of DO Hebb \cite{hebb}

cond-mat.soft

An analytical analysis of vesicle tumbling under a shear flow

Vesicles under a shear flow exhibit a tank-treading motion of their membrane, while their long axis points with an angle < 45 degrees with respect to the shear stress if the viscosity contrast between the interior and the exterior is not large enough. Above a certain viscosity contrast, the vesicle undergoes a tumbling bifurcation, a bifurcation which is known for red blood cells. We have recently presented the full numerical analysis of this transition. In this paper, we introduce an analytical model that has the advantage of being both simple enough and capturing the essential features found numerically. The model is based on general considerations and does not resort to the explicit computation of the full hydrodynamic field inside and outside the vesicle.

physics.bio-ph

On the velocity distributions of the one-dimensional inelastic gas

We consider the single-particle velocity distribution of a one-dimensional fluid of inelastic particles. Both the freely evolving (cooling) system and the non-equilibrium stationary state obtained in the presence of random forcing are investigated, and special emphasis is paid to the small inelasticity limit. The results are obtained from analytical arguments applied to the Boltzmann equation along with three complementary numerical techniques (Molecular Dynamics, Direct Monte Carlo Simulation Methods and iterative solutions of integro-differential kinetic equations). For the freely cooling fluid, we investigate in detail the scaling properties of the bimodal velocity distribution emerging close to elasticity and calculate the scaling function associated with the distribution function. In the heated steady state, we find that, depending on the inelasticity, the distribution function may display two different stretched exponential tails at large velocities. The inelasticity dependence of the crossover velocity is determined and it is found that the extremely high velocity tail may not be observable at ``experimentally relevant'' inelasticities.

cond-mat.stat-mech

Thermally Activated Dynamics of the Capillary Condensation

This paper is devoted to the thermally activated dynamics of the capillary condensation. We present a simple model which enables us to identify the critical nucleus involved in the transition mechanism. This simple model is then applied to calculate the nucleation barrier from which we can obtain informations on the nucleation time. We present a simple estimation of the nucleation barrier in slab geometry both in the two dimensional case and in the three dimensional case. We extend the model in the case of rough surfaces which is closer to the experimental case and allows comparison with experimental datas.

cond-mat.soft