The past few years have seen considerable interest in findings of abnormal brain connectivity in the autism spectrum disorders (ASD). We review recent work from neuroimaging and other sources, and argue that there is considerable convergent evidence suggesting that connectivity is disrupted in ASD. We point to evidence both of local over-connectivity and of long-distance under-connectivity, and...

INTRODUCTION Degraded social function, disinhibition, and stereotypy are defining characteristics of frontotemporal dementia (FTD), manifesting in both the behavioral variant of frontotemporal dementia (bvFTD) and semantic dementia (SD) subtypes. Recent neuroimaging research also associates FTD with alterations in the brain's intrinsic connectivity networks. The present study explored the relat...

We study neural connectivity in cultures of rat hippocampal neurons. We measure the neurons’ response to an electric stimulation for gradual lower connectivity, and characterize the size of the giant cluster in the network. The connectivity undergoes a percolation transition described by the critical exponent β ≃ 0.65. We use a theoretic approach based on bond–percolation on a graph to describe...

The purpose of the present paper was to review psychological theories of autism, and to integrate these theories with neurobiological findings. Cognitive, theory of mind, language and coherence theories were identified, and briefly reviewed. Psychological theories were found not to account for the rigid/repetitive behaviours universally described in autistic subjects, and underlying neurobiolog...

We study the graph coloring problem over random graphs of finite average connectivity c. Given a number q of available colors, we find that graphs with low connectivity admit almost always a proper coloring, whereas graphs with high connectivity are uncolorable. Depending on q, we find the precise value of the critical average connectivity c(q). Moreover, we show that below c(q) there exists a ...

While the literature on aberrant long-distance connectivity in autism spectrum disorder (ASD) has grown fast over the past decade, little is known about local connectivity. We used regional homogeneity and local density approaches at different spatial scales to examine local connectivity in 29 children and adolescents with ASD and 29 matched typically developing participants, using resting stat...

In wireless sensor network (WSN), preditibution of cryptographic keys is possibly the most practical approach to perfect network communications. In this paper, we propose a new secret key predistribution scheme to achieve a higher connectivity in WSN. For this we combine a random key predistribution scheme and hash chain method based on the prior knowledge of sensor node deployment. The propose...

The small world phenomenon, that consistently occurs in numerous existing networks, refers to two similar but different properties — small average distance and the clustering effect. We consider a hybrid graph model that incorporates both properties by combining a global graph and a local graph. The global graph is modeled by a random graph with a power law degree distribution, while the local ...