Theoretical and empirical studies have begun to explore the structure and function of the human brain from a system perspective, using network science to abstractly model the brain as a set of nodes (e.g., brain regions) and edges (e.g., structural or functional connections) [1]. Within this framework, many studies have identified a small set of highly connected network nodes, referred to as hu...

Hub location problems, with the hub-and-spoke network structure, involve locating hub facilities, allocating the non-hubs (spokes) to the hubs, and determining the path for each origin-destination pair. In a pure hub-and-spoke network, all hubs, which act as intermediate switching or transshipment points for internodal flows, are fully interconnected and none of the non-hubs are directly connec...

Uncovering interactions between genes, gene networks, is important to increase our understanding of intrinsic cellular processes and responses to external stimuli such as drugs. Gene networks can be computationally inferred from repeated measurements of gene expression, using algorithms, which assume that each gene is controlled by only a small number of other proteins. Here, by extending the t...

Vast numbers of organizations and individuals communicate every day by sending messages over social networks. These messages, however, are subject to change as they propagate through the network. This paper attempts to calculate the distortion of a message as it propagates in a social network with a scale free topology, and to establish a remedial process in which a node will correct the distor...

Brain regions in the mammalian cerebral cortex are linked by a complex network of fiber bundles. These inter-regional networks have previously been analyzed in terms of their node degree, structural motif, path length and clustering coefficient distributions. In this paper we focus on the identification and classification of hub regions, which are thought to play pivotal roles in the coordinati...

Recent evidence suggests that some brain areas act as hubs interconnecting distinct, functionally specialized systems. These nexuses are intriguing because of their potential role in integration and also because they may augment metabolic cascades relevant to brain disease. To identify regions of high connectivity in the human cerebral cortex, we applied a computationally efficient approach to ...

Network studies of large-scale brain connectivity have demonstrated that highly connected areas, or "hubs," are a key feature of human functional and structural brain organization. We use resting-state functional MRI data and connectivity clustering to identify multi-network hubs and show that while hubs can belong to multiple networks their degree of integration into these different networks v...

The evolution of hubs etabolic networks rely heavily on a few crucial metabolic hubs, such as ATP, NADH, and glutamate, that are widely used in many cellular biochemical reactions. In contrast to hubs, most other metabolites each participate in only a few reactions. Now, research from Thomas Pfeiffer, Orkun Soyer, and Sebastian Bonhoeffer (ETH Zürich, Switzerland) shows that hubs are the natura...

Biological networks often show a scale-free power-law distribution. Furthermore, leathal genes tend to form functional hubs whereas non-leathal disease genes are located at the periphery. Uni-dimensional analyses, however, are flawed. Here we report two distinct scale-free networks; a protein-protein interaction (PPI) and a perturbationsensitivity (PSN) network. Hubs of both networks demonstrat...