Infectious diseases have moulded the development of the human species more than any other biological or abiological factor. They have influenced not only our biology, but also our history and political development; from the outcome of wars to the success of empires, and from the pace of technological advance to the structure of society itself. The introduction of smallpox to the Americas by Eur...

The theorem of Fraenkel and Simpson states that the maximum number of distinct squares that a word w of length n can contain is less than 2n. This is based on the fact that no more than two squares can have their last occurrences starting at the same position. In this paper we show that the maximum number of the last occurrences of squares per position in a partial word containing one hole is 2...

Genetic epidemiological studies suggest that individual variation in susceptibility to schizophrenia is largely genetic, reflecting alleles of moderate to small effect in multiple genes. Molecular genetic studies have identified several potential regions of linkage and two associated chromosomal abnormalities, and evidence is accumulating in favour of several positional candidate genes. Current...

Refinement of protein structures from a correct topology to atomically detailed resolution has proven remarkably difficult. Jian et al. (in this issue of Structure) illustrate a significant advance in this task by carefully incorporating into the refinement process many body interactions extracted from fragment statistics.