Single molecule detection has contributed to our understanding of the unique mechanisms of life. Unlike artificial man-made machines, biological molecular machines integrate thermal noises rather than avoid them. For example, single molecule detection has demonstrated that myosin motors undergo biased Brownian motion for stepwise movement and that single protein molecules spontaneously change t...

T HE recorded ballistocardiogram is a distorted representation of cardiovascular forces.1, 2, 3 These forces, which are generated by the contracting heart and accelerated blood, are transformed in transmission to the surface of the body. The resultant body movement is determined by the amplitudes of the transmitted forces and the mechanical response of the body. It is the purpose of this paper ...

The present paper deals with an interesting problem, unresolved for more than 70 years, concerning class of diffusion-controlled periodic chemical reactions, where macroscopically observed diffusion action attains, with appreciable accuracy, the value of Planck’s quantum _. Starting from the classical Einstein–von Smoluchowski theory of Brownian movement and making use of a significant fact tha...

The fast dynamics generated by the Brownian motion of particles in colloidal drops, and the related relaxation during drying, which play key roles in suspension systems, were investigated incorporating multispeckle diffusing wave spectroscopy (MSDWS). MSDWS equipment was implemented to analyze the relaxation properties of suspensions under a nonergodic and nonstationary drying process, which ca...

This article deals with the study of the two-dimensional mixed convection magnetohydrodynamic (MHD) boundary layer of stagnation-point flow over a stretching vertical plate in porous medium filled with a nanofluid. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis in the presence of thermal radiation. The skin-friction coefficient, Nusselt number an...

The current correlation function is determined from dynamic light scattering measurements of a suspension of particles with hard spherelike interactions. For suspensions in thermodynamic equilibrium we find scaling of the space and time variables of the current correlation function. This finding supports the notion that the movement of suspended particles can be described in terms of uncorrelat...

Cell movement--for example, during embryogenesis or tumor metastasis--is a complex dynamical process resulting from an intricate interplay of multiple components of the cellular migration machinery. At first sight, the paths of migrating cells resemble those of thermally driven Brownian particles. However, cell migration is an active biological process putting a characterization in terms of nor...

The biased movement of a Brownian particle in a periodic potential fluctuating between a flat and a kinked ratchet state, as first studied by Chauwin, Ajdari, and Prost, is examined. The purpose is to study the physical origin of the frequency-dependent direction reversal of the biased Brownian motion in this system. We show that the existence of the directional reversal depends not only on the...

In order to understand the basic physics of muscle contraction and molecular motor movement, we develop a conceptual model for nonequilibrium free energy transduction based on a 2-dimensional diiusion in a periodic force eld. It is shown that a nonconservative force is suucient and necessary for a steady-state with circular ux, but is not suucient for a global uni-directional transport thermal ...

The constant dynamic movement of synapses and their components has emerged in the last decades as a key feature of synaptic transmission and its plasticity. Intramolecular protein movements drive conformation changes important to transduce transmitter binding into signaling. Constant cytoskeletal rearrangements power synapse shape movements. Vesicular trafficking at the pre- and postsynapse und...