Alleged footprints of early Americans found in volcanic rock in Mexico are either extremely old - more than 1 million years older than other evidence of human presence in the Western Hemisphere - or not footprints at all, according to a new analysis published this week in Nature.

As a boy growing up in Brazil 40 years ago, Marc A. Meyers marveled at the lightweight toughness of toucan beaks that he occasionally found on the forest floor. Now a materials scientist and professor of mechanical and aerospace engineering at UCSD's Jacobs School of Engineering, Meyers said makers of airplanes and automobiles may benefit from the first ever detailed engineering analysis of toucan beaks conducted in his lab.

Changes in bird song could be used as an early warning system to detect man-made ecological disturbances, new research published in the British Ecological Society's Journal of Applied Ecology has found. Although much previous research has focused on bird song and vocal mimicry, this is the first study to analyse the role played by habitat loss and fragmentation on song-matching.

A study in guinea pigs suggests that a drug commonly given to pregnant women to help their babies mature enough to survive can also affect the brains and behaviour of their grandchildren too. The finding raises a difficult dilemma for doctors, for while the drug undoubtedly saves lives, its side effects could last for generations.

Researchers at the U.S. Department of Energy's Brookhaven National Laboratory have just launched a web-based 3-D digital atlas browser and database of the brain of a popular laboratory mouse (see http://www.bnl.gov/CTN/mouse/).

A team of scientists at Yale University has completed the first comprehensive map of the proteins and kinase signaling network that controls how cells of higher organisms operate, according to a report this week in the journal Nature.

Researchers at the San Francisco VA Medical Center have uncovered part of the genetic mechanism that causes new arteries to grow in response to blocked arteries.

Putting antibacterial coatings on hip and knee implants and biomedical devices such as catheters could cut infection rates following surgery and significantly reduce health care costs and improve quality of life for patients, researchers at the University of South Australia have found.