Rube Goldberg—the cartoonist who devised complex machines for simple tasks—would have smiled at one of leptin's mechanisms for curbing insulin release. As Hinoi et al. show, the fat-derived hormone enlists the sympathetic nervous system to prevent bone-making cells from releasing a molecule that prods the pancreas to discharge insulin.

Research done by scientists in Italy and Switzerland has shown that carbon nanotubes may be the ideal "smart" brain material. Their results, published December 21 in the advance online edition of the journal Nature Nanotechnology, are a promising step forward in the search to find ways to "bypass" faulty brain wiring.

Biologists have tracked down genes that control the handedness of snail shells, and they turn out to be similar to the genes used by humans to set up the left and right sides of the body.

Researchers have made several, subtle changes in the structure of a key protein, dramatically increasing its ability to drive blood clotting, according to a study published in a December edition of the Journal of Thrombosis and Haemostasis. The findings have profound implications for the treatment of hemophilia, the inherited blood disorder that causes easy or excessive bleeding in 30,000 Americans.