Analyses of contact-tracing data on the spread of infectious disease, combined with mathematical models, show that control measures require better knowledge of variability in individual infectiousness.

In female mammals, one of two X chromosomes has to be shut down during early development. To what extent does this 'imprinted X-chromosome inactivation' involve the history of the chromosome?

Chaos, goes conventional wisdom, can only be a malign influence in telecommunications. But a technique that uses chaotically varying signals to transmit information more privately may help it shed that bad-boy image.