PubMed Health⌕ Search

Biomedical subjects

P Grigolini

Publications and source records attributed to P Grigolini.

At least 19 recordsLinked to original sources
PubMed2000

Fluctuation-dissipation process without a time scale

We study the influence of a dissipation process on diffusion dynamics triggered by fluctuations with long-range correlations. We make the assumption that the perturbation process involved is of the same kind as those recently studied numerically and theoretically, with a good agreement between theory and numerical treatment. As a result of this assumption the equilibrium distribution departs from the ordinary canonical distribution. The distribution tails are truncated, the distribution border is signaled by sharp peaks, and, in the weak dissipation limit, the central distribution body becomes identical to a truncated Levy distribution.

Journal Article↗
PubMed1994

Fractal properties of ion channels and diffusion.

We focus our attention on a fractal model recently proposed by Liebovitch to account for the lack of a time scale in ion channel kinetics. We establish a connection between the dwell-time distributions and the correlation time of the ion channel signal, thereby making it possible to derive analytical predictions on the diffusion properties of a random walk constructed from the sum of the current fluctuations of ion channels. With the help of a numerical simulation of the Liebovitch model, it is shown that the Hurst analysis can provide a reliable determination of the standard (or anomalous) diffusion properties. On the basis of results of computer simulation we argue that by applying the Hurst analysis to the experimental distribution of closed times it is possible, in principle, to establish whether the Liebovitch model is valid.

Computer Simulation↗