– We present a simple mesoscale field theory inspired by rate-independent plasticity that reflects the symmetry of the deformation process. We parameterize the plastic deformation by a scalar field which evolves with loading. The evolution equation for that field has the form of a Hamilton-Jacobi equation which gives rise to cusp-singularity formation. These cusps introduce irreversibilities an...

In many regions of the brain, the activity-dependent changes in synaptic strength depend on the frequency and timing of presynaptic stimulation and postsynaptic activity (synaptic plasticity), as well as the history of activity at those synapses (metaplasticity). The Bienenstock, Cooper and Munro (BCM) theory made several assumptions about how synapses modify and these have helped to guide vari...

We present a finite deformation constitutive theory for non-cohesive granular media. The material model falls in the family of the so-called Cam-clay theories. As typical of Cam-clay models, soil is assumed to be frictional with a logarithmic-type compression. The same state boundary surface––described by ellipses––is taken as yield and plastic potential surface. Hardening is related only to pl...

landmark based geometric morphometrics and comparison of meristic characters was used to understand potential differences between populations of waspi in mashkil and mokran basins. 97 specimens of waspies were caught (64 from mashkil river and 33 from sarbaz river). 14 landmarks were digitized on pictures taken from left side of specimens and meristic characters were counted. data were analyzed...

We consider the extension of the classical mathematical theory of plasticity to frictional materials. It is shown that the apparently nonassociated plastic flow characteristics often observed in such materials can be accounted for by models that are variational in structure. In addition, the theory predicts a number of new terms and functional relationships that appear to have particular releva...

Theories of receptive field plasticity and information storage make specific assumptions for how synapses are modified. I give a personal account of how testing the validity of these assumptions eventually led to a detailed understanding of long-term depression and metaplasticity in hippocampal area CA1 and the visual cortex. The knowledge of these molecular mechanisms now promises to reveal wh...

A short account is given of the BCM theory of synaptic plasticity: assumptions, consequences , comparison with experiment and statistical properties. In addition a framework for comparison with other theoretical ideas is presented.

reelin is an extracellular matrix neuroprotein which plays important roles during development and maturation of cerebellum. in the postnatal cerebellum, reelin is synthesized by cerebellar granule cells and secreted to extracellular matrix. this secreted protein modulates adult synaptic function, neurotransmitter release and regulates plasticity. exercise has beneficial effects on central nervo...

Adaptive phenotypic plasticity allows organisms to cope with environmental variability, and yet, despite its adaptive significance, phenotypic plasticity is neither ubiquitous nor infinite. In this review, we merge developmental and population genetic perspectives to explore costs and limits on the evolution of plasticity. Specifically, we focus on the role of modularity in developmental geneti...