Here’s a chance for medical students who are budding writers to write a biography of 5000 words and win £200 (€260; $400). The Society of Medical Writers holds the Roger Bacon biography award every two years, and the closing date for the next one is 1 December 2009. Entry is free and the biography can be about anyone with medical connections—from family and friends to the famous. The winning entry will be published in The Writer. Contact Dr Dorothy Crowther, Corner Croft, Lonsties, Keswick, Cumbria CA12 4TD for entry forms.

The secret of how the insect repellent known as DEET (N,N-diethyl-meta-toluamide) discourages bloodsucking insects from feasting on humans is its ability to block odour receptors that require the olfactory protein OR83b. By blocking these receptors, DEET masks the human odours that smell like “food” to a passing insect (Science published online 13 March 2008; doi: 10.1126/science.1153121). This discovery should help in the design of safer and more effective insect repellents.

Neural development depends on sufficient DHA (docosahexaenoic acid). To explore whether infants’ development is …