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J C Lévy

Publications and source records attributed to J C Lévy.

13 recordsLinked to original sources
PubMed2000

Magnetic microstructure of the spin reorientation transition: a computer experiment.

The scenario of the spin reorientation in two-dimensional films within first-order anisotropy approximation is theoretically studied by means of Monte Carlo simulations. The magnetic microstructure is investigated as a function of the ratio of the perpendicular anisotropy energy to the dipolar one. If the anisotropy dominates, out-of-plane domains will be found while in-plane vortices appear for a vanishing anisotropy. In the range of comparable anisotropy and dipolar energies a complex domain pattern evolves yielding a continuous transition between the two structures. The structure with equally distributed magnetic moment orientations is stable at the point where anisotropy and dipolar energies cancel each other.

Journal Article↗
PubMed1997

A 'Neural Sampling Theory (NST)' of learning and memory mechanisms.

The purpose of the Neural Sampling Theory (NST) is to propose a plausible neurobiological explanation for some general properties of learning and memory (LM) phenomena, based on the parallelism and redundancy of the nervous system organization; on the psychological side, the NST is inspired by the Stimulus Sampling and Encoding Variability theories. The sampling process which is its core, is not purely random; it depends on temporal and intensity factors. The NST may be implemented at different levels of the nervous system: synapse, neuron, assembly of neurons. Moreover, it may be incorporated in other formal models and improve their degree of neural realism. For instance it allows to give a more realistic representation of the connection weight in the connectionist models and of the noisy character of the nervous system.

Animals↗
PubMed1977

[Liver extract effect on liver microsomal system and on an experimental model of intoxication].

A lyophilized liver extract (FLR) lengthens hexobarbital action in control rats ; it decreases slightly the induction of hepatic microsomal enzymes and normalizes diphenylhydantoin protection against electroshock seizure in phenobarbital-treated animals ; in the event of a CC14 intoxication, this extract reestablishes values close to normal for mebubarbital metabolism in mice and for BSP clearance in rats. FLR could act in regularizing drug metabolism.

Animals↗