Digital Edge

On average, digital mammography is as good as film at detecting breast cancers. And for women fifty and younger, pre- and perimenopausal women, and women with dense breasts, digital does better—detecting up to 28 percent more tumors—according to a landmark trial conducted by the American College of Radiology Imaging Network in conjunction with Brown’s Center for Statistical Sciences. The New England Journal of Medicine published the study on its Web site September 16. The screening trial enrolled 49,528 women at thirty-three sites.. The article’s coauthor, community health professor Constantine Gatsonis, who heads Brown’s new Center for Statistical Sciences, said that because of its size and rigor, the study provides some of the best data gathered on mammogram accuracy. “Neither film nor digital mammography is able to catch every cancer,” he said. “So this study data can be used to develop and improve mammography in the coming years.”

Evil Twin

In the September 8 issue of Nature, graduate student Prasanna Satpute-Krishnan and Assistant Professor Tricia Serio (both of the Department of Molecular Biology, Cell Biology, and Biochemistry) published research on the mysterious molecular machinery behind prions, infectious proteins that cause fatal brain ailments such as mad cow disease in animals and Creutzfeldt-Jacob disease in humans. The biologists found that when healthy protein comes in contact with the infectious prion form in yeast, the healthy protein converts to the prion form, rendering it infectious. In an instant, good protein goes bad. Results help explain how prions multiply and lead to illness. And, because similar protein self-replication occurs in neurodegenerative diseases, the findings may also help explain the progression of Alzheimer’s, Parkinson’s, and Huntington’s diseases.

Seismic Twist

In the same issue of Nature, a team of scientists including geology professor Donald Forsyth shed light on the birth of oceanic plates. The team found unexpected changes in the patterns of seismic velocity and electrical conductivity near the East Pacific Rise, a vast volcanic mountain range under the Pacific Ocean. The research represents the first time seismic and electromagnetic data were analyzed in tandem from the 1995 Mantle Electromagnetic and Tomography, or MELT, Experiment, one of the largest marine geophysical experiments ever conducted.