A new model ecosystem consisting of many interacting species is introduced. The species are connected through a random matrix with a given connectivity . It is shown that the system is organized close to a boundary of marginal stability in such a way that fluctuations follow power law...

The topology of the proteome map revealed by recent large-scale hybridization methods has shown that the distribution of protein-protein interactions is highly heterogeneous, with many proteins having few links while a few of them are heavily connected. This particular topology is shared by...

Why are some ecosystems so rich, but yet contain so many rare species? High species diversity, together with rarity, is a general trend in neotropical forests and coral reefs. But the origin of such diversity and the consequences of food web complexity in both species abundances and temporal...

In a recent paper, we analysed the dynamics of traffic flow in a simple, square lattice architecture. It was shown that a phase transition takes place between a free and a congested phase. The transition point was shown to exhibit optimal information transfer and wide fluctuations in time, with...

Random-text models have been proposed as an explanation for the power law relationship between word frequency and rank, the so-called Zipf's law. They are generally regarded as null hypotheses rather than models in the strict sense. In this context, recent theories of language emergence and...