Recent experiments on cortical neural networks have revealed the existence of well-defined avalanches electrical activity. Such been claimed to be generically scale invariant—i.e. power law distributed—with many exciting implications in neuroscience. Recently, a self-organized model has proposed by Levina, Herrmann and Geisel explain this empirical finding. Given that (i) dynamics is dissipative (ii) there loading mechanism progressively 'charging' background synaptic strength,...

The performance of attractor neural networks has been shown to depend crucially on the heterogeneity underlying topology. We take this analysis a step further by examining effect degree-degree correlations---assortativity---on neural-network behavior. make use method recently put forward for studying correlated and dynamics thereon, both analytically computationally, which is independent how topology may have evolved. show robustness noise greatly enhanced in assortative (positively...

In this work, we introduce two spatiotemporal colored bounded noises, based on the zero-dimensional Cai-Lin and Tsallis-Borland noises. Then study characterize dependence of defined stochastic processes both a temporal correlation parameter $\ensuremath{\tau}$ spatial coupling $\ensuremath{\lambda}$. particular, found that varying $\ensuremath{\lambda}$ may induce transition distribution noise from bimodality to unimodality. With aim investigating role played by noises in nonlinear dynamical...

Cell polarization (cued or uncued) is a fundamental mechanism in cell biology. As an alternative to the classical Turing bifurcation, it has been proposed that onset of polarity might arise by means well-known phenomenon wave-pinning [Gamba et al., Proc. Natl. Acad. Sci. USA 102, 16927 (2005)]. A particularly simple and elegant deterministic model based on Edelstein-Keshet coworkers [Biophys. J. 94, 3684 (2008)]. This consists small biomolecular network where active membrane-bound factor...

Abstract Gene switching dynamics is a major source of randomness in genetic networks, also the case large concentrations transcription factors. In this work, we consider common network motif - positive feedback factor on its own synthesis and assess response to extrinsic noises perturbing gene deactivation variety settings where might operate. These are representative distinct cellular types, abundance factors ratio between protein rates. By investigating noise-induced transitions among...

In this paper, we study the Indian Railway Network (IRN) as a weighted complex network in which railway stations are considered nodes, while weights on edges represent number of trains directly linking two stations.Apart from small-world characteristics and exponential distributions node-degrees edge-weights IRN, explore correlations amount traffic with topology network.The IRN is found to be accumulated interconnected groups concentrated links between large stations.We also identify most...

Here we numerically study a model of excitable media, namely, network with occasionally quiet nodes and connection weights that vary activity on short-time scale. Even in the absence stimuli, this exhibits unstable dynamics, nonequilibrium phases -including one which global wanders irregularly among attractors- 1/f noise while system falls into most irregular behavior. A net result is resilience results an efficient search attractors space can explain origin certain phenomenology neural,...

Fractal behaviour, i.e. scale invariance in spatio-temporal dynamics, have been found to describe and model many systems nature, particular fluid mechanics geophysical related geometrical objects, like the convective boundary layer of cumulus cloud fields, topographic landscapes, solar granulation patterns, observational astrophysical time series, light curves pulsating stars. The main interest study fractal properties such physical phenomena lies close relationships they with chaotic...

ABSTRACT Fractal fingerprints have been found recently in the light curves of several δ Scuti stars observed by Convection Rotation and planetary Transits(CoRoT) satellite. This sole fact might pose a problem for detection pulsation frequencies using classical pre-whitening techniques, but it is also potentially rich source information about physical mechanisms associated with stellar variability. Assuming that curve composed superposition oscillation modes fractal background noise, this...

We discuss an attractor neural network in which only a fraction ρ of nodes is simultaneously updated. In addition, the has heterogeneous distribution connection weights and, depending on current degree order, connections are changed at random by factor Φ short-time scales. The resulting dynamic attractors may become unstable certain range thus ensuing chaotic itineracy highly depends ρ. For intermediate values ρ, we observe that number visited increases with and trajectory change from...

It is well-known that gene activation/deactivation dynamics may be a major source of randomness in genetic networks, also the case large concentrations transcription factors. In this work, we investigate effect realistic extrinsic noises acting on deactivation common network motif - positive feedback factor its own synthesis under variety settings, i.e., distinct cellular types, distribution proteins and properties external perturbations. At variance with standard models where perturbations...

The behaviour of many complex dynamical systems has been found to depend crucially on the structure underlying networks interactions. An intriguing feature empirical is their assortativity—i.e., extent which degrees neighbouring nodes are correlated. However, until very recently it was difficult take this property into account analytically, most work being exclusively numerical. We get round problem by considering ensembles equally correlated graphs [1] and apply novel technique case...

Excitable media may be modeled as simple extensions of the Amari–Hopfield network with dynamic attractors. Some nodes chosen at random remain temporarily quiet, and some edges are switched off to adjust connectivity, while weights other vary activity. We conclude on optimum wiring topology describe nonequilibrium phases criticality edge irregular behavior.