▪ Prion infections, such as mad cow disease, may incubate without symptoms for years. A technique that amplifies tiny amounts of prions in the blood successfully diagnosed infected hamsters within 20 days after exposure to prions and three months before symptoms appeared.

Science, July 7

▪ A radar system emits signals that appear as noise to other devices, thus enabling it to escape detection. Properly tuned, the stealth radar can also image objects behind walls.

Ohio State University announcement, June 26

▪ Abnormal amygdalas may be the root of autism. A postmortem accounting reveals that adult autistic males have about 1.5 million (12 percent) fewer neurons in that brain region, important for memory and emotion.

Journal of Neuroscience, July 19

▪ The ability to empathize does not appear to be restricted to primates. Mice became more sensitive to pain after having seen cage mates in some distress.

Science, June 30