Search results for " environmental noise"
showing 3 items of 3 documents
Harmony perception and regularity of spike trains in a simple auditory model
2013
A probabilistic approach for investigating the phenomena of dissonance and consonance in a simple auditory sensory model, composed by two sensory neurons and one interneuron, is presented. We calculated the interneuron’s firing statistics, that is the interspike interval statistics of the spike train at the output of the interneuron, for consonant and dissonant inputs in the presence of additional "noise", representing random signals from other, nearby neurons and from the environment. We find that blurry interspike interval distributions (ISIDs) characterize dissonant accords, while quite regular ISIDs characterize consonant accords. The informational entropy of the non-Markov spike train …
A stochastic interspecific competition model to predict the behaviour of Listeria monocytogenes in the fermentation process of a traditional Sicilian…
2008
The present paper discusses the use of modified Lotka-Volterra equations in order to stochastically simulate the behaviour of Listeria monocytogenes and Lactic Acid Bacteria (LAB) during the fermentation period (168 h) of a typical Sicilian salami. For this purpose, the differential equation system is set considering T, pH and aw as stochastic variables. Each of them is governed by dynamics that involve a deterministic linear decrease as a function of the time t and an "additive noise" term which instantaneously mimics the fluctuations of T, pH and aw. The choice of a suitable parameter accounting for the interaction of LAB on L. monocytogenes as well as the introduction of appropriate nois…
Stochastic model for a biological complex system: analysis of the bacterial growth in food products
2012
The Physics of Complex Systems has recently taken a more and more important role in the description of natural systems because of the interactions, both deterministic and noisy, between such systems and the environment. In particular the noise plays a relevant role in biological systems, whose dynamics is strongly influenced by environmental variables subject to random fluctuations. In this work a stochastic model is exploited to reproduce the growth of bacteria in food of animal origin. Specifically the dynamics of a bacterial species, Listeria monocytogenes, is analyzed in the presence of lactic acid bacteria (LAB) during the period of the fermentation of meat products. The model, based o…