News Scan Briefs; December 2002; Scientific American Magazine; by Charles Choi, Tariq Malik, Sarah Graham; 2 Page(s)

Dentures Begone: Don't cast pearls before swine-get pearly whites from them instead. A research team led by molecular biologist Pamela C. Yelick of the Forsyth Institute in Boston removed unerupted molars from six-month-old pigs and dissolved them with enzymes. Cells from the resulting soup were placed in a biodegradable polymer scaffolding and implanted in the abdomens of immunosuppressed rats, close to bloodrich tissues. Thirty weeks later two-millimeter-wide molar crowns emerged, complete with pulp chambers, root tips and bonelike layers of dentin and, in a first, enamel. The scientists, who described their findings in the October 1 Journal of Dental Research, say it may be possible a decade from now to grow living substitutes for lost human teeth, perhaps in tailored shapes and sizes.-Charles Choi

Keyboard Cops: Software designed to guard the nation's highsecurity networks from hackers detects suspicious anomalies in system traffic based purely on statistics and is usually correct only 60 to 80 percent of the time. Computer scientist Shambhu Upadhyaya of the University of Buffalo explained that his team has a more reliable and efficient way. Their prototype software simply monitors commands that users enter, comparing their behavior with the well-defined habits of legitimate users. The new program can double-check suspicious behavior against every user's unique profile of activity to sort out masquerading intruders from genuine users. The "user-level anomaly detection system" was presented in October at the military communications conference MILCOM 2002 in Anaheim, Calif. Upadhyaya says that the software is successful 94 percent of the time but thinks near 100 percent reliability is years away.-Charles Choi