Mice with a disrupted circadian rhythm gene overeat and develop problems related to obesity, suggesting that in mammals the 24-hour clock cycle is finely tuned to metabolic functions. Science Express, April 21
Elderly nursing-home residents often are not given sleeping pills, for fear that the compounds will increase the risk of falls. Ironically, a study finds that insomnia itself, not sleep medication, predicts future falls. Journal of the American Geriatrics Society, March 30 online
Soft organic tissue apparently survived in a fossilized leg bone of a 68-million-year-old Tyrannosaurus rex—a surprise because organic molecules should last only 100,000 years. If truly original tissue, the material may hold recoverable genetic data. Science, March 25
Farmed salmon seem able to spread potentially lethal parasitic sea lice to wild cousins more readily than previously thought—sometimes out to 30 kilometers from a farm only 200 meters long. Proceedings of the Royal Society B, March 30
