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Neurons communicate through spikes; their arrangement in different sequences generates the neural code. Spikes are transmitted between neurons via synapses; the mechanism underlying synaptic transmission involves numerous processes including neurotransmitter release and diffusion, postsynaptic receptor activation, and intrinsic electrore-sponsiveness. Based(More)
We present a simple spiking model that extends the classical integrate-and-ÿre neuron to reproduce the diierent dynamical behaviors observed in cerebellar granule cells. The model is two dimensional: in addition to the membrane potential V , we consider a gating variable that models a slow K + current. This current plays a major role in generating the(More)
The Common Criteria (CC) certification framework defines a widely recognized, multi-domain certification scheme that aims to provide security assurances about IT products to consumers. However, the CC scheme does not prescribe a monitoring scheme for the CC practice, raising concerns about the quality of the security assurance provided by the certification(More)
In this paper we extend the Celada-Seiden (CS) model of the humoral immune response to include infectious virus and cytotoxic T lymphocytes (cellular response). The response of the system to virus involves a competition between the ability of the virus to kill the host cells and the host's ability to eliminate the virus. We find two basins of attraction in(More)
Multielectrode arrays allow recording of the activity of many single neurons, from which correlations can be calculated. The functional roles of correlations can be revealed by measures of the information conveyed by neuronal activity; a simple formula has been shown to discriminate the information transmitted by individual spikes from the positive or(More)
A nerve cell receives multiple inputs from upstream neurons by way of its synapses. Neuron processing functions are thus influenced by changes in the biophysical properties of the synapse, such as long-term potentiation (LTP) or depression (LTD). This observation has opened new perspectives on the biophysical basis of learning and memory, but its(More)
We investigate the problem of speciation and coexistence in simple ecosystems when the competition among individuals is included in the Eigen model for quasispecies. By suggesting an analogy between the competition among strains and the diffusion of a chemical inhibitor in a reaction-diffusion system, the speciation phenomenon is considered the analogous of(More)
  • Michele Bezzi
  • 2007
Data holders use data masking techniques for limiting disclosure risk in releasing sensitive datasets. Disclosure risk is often expressed in terms of rareness or of probability of re-identification. We propose a novel measure of disclosure risk, based on Shannon entropy, which combines together these two approaches. This measure represents the uncertainty(More)
Mobile devices consume significant amounts of information, from different sources. Thus they often deal also with sensitive or confidential data, in places or situations that could be not appropriate, or not compliant with a corporate policy: context-aware access/usage control solutions can counter such situations. We propose a prototype, called ProtectMe,(More)