Mark Buchanan

Networks in cell biology

Introduction 1. Network views of the cell Paolo De Los Rios and Michele Vendruscolo 2. Transcriptional regulatory networks Sarath Chandra Janga and M. Madan Babu 3. Transcription factors and gene regulatory networks Matteo Brilli, Elissa Calistri and Pietro Lio 4. Experimental methods for protein interaction identification Peter Uetz, Bjorn Titz, Seesandra V. Rajagopala and Gerard Cagney 5. Modeling protein interaction networks Francesco Rao 6. Dynamics and evolution of metabolic networks Daniel Segre 7. Hierarchical modularity in biological networks: the case of metabolic networks Erzsebet Ravasz Regan 8. Signalling networks Gian Paolo Rossini Appendix 1. Complex networks: from local to global properties D. Garlaschelli and G. Caldarelli Appendix 2. Modelling the local structure of networks D. Garlaschelli and G. Caldarelli Appendix 3. Higher-order topological properties S. Ahnert, T. Fink and G. Caldarelli Appendix 4. Elementary mathematical concepts A. Gabrielli and G. Caldarelli References.

A Networked World

Just over a decade ago, in June 1998, a curious three-page paper appeared in Nature. In it, the authors – two applied mathematicians – reported a link between the structure of the US electrical grid and the wiring of a nematode worms neural system. They also noted that these patterns were strikingly similar in their structure to the social networks of Hollywood actors, one of the few such networks for which the authors could find extensive data. It is hard to imagine a more bizarre melding of topics in one study.

In search of the black swans

In 1890 an electricity company enticed the German physicist Max Planck to help it in its efforts to make more efficient light bulbs. Planck, as a theorist, naturally started with the fundamentals and soon became enmeshed in the thorny problem of explaining the spectrum of black-body radiation, which he eventually did by introducing the idea – a purely formal assumption, as he then considered it – that electromagnetic energy can only be emitted or absorbed in discrete quanta. The rest is history. Electric light bulbs and mathematical necessity led Planck to discover quantum theory and to kick start the most significant scientific revolution of the 20th century.

Synchrotrons scale down

For any scientist who has tried in vain to book time at a synchrotron facility, help is at hand. Physicists in Japan have built a synchrotron source that is small enough to fit in a normal laboratory, and which, they claim, can perform nearly as well as the much larger conventional sources.

Paper resurfaces from lost physicist

The Italian physicist Ettore Majorana, who mysteriously disappeared while travelling by ship from Palermo to Naples in 1938 at the age of 32, is best known for his contributions to quantum theory. A professor at Naples University and a former student of Enrico Fermi, his name lives on today in terms such as Majorana phases and Majorana particles – particles that are their own antiparticles. But a little-known paper by Majorana that has just been published in English for the first time reveals he also thought deeply about the relevance of physics to the social sciences.