Calorie-Burning Fat

Once thought to disappear after infancy, the calorie-burning tissue known as brown fat may actually be keeping some adults slim. Newborns have brown fat to help generate body heat, but it seems to melt away as part of the aging process. A new study shows that some adults, especially those with a healthy body mass index, maintain reserves of the good fat that is metabolically active. The work, published in the April 9 New England Journal of Medicine, could potentially point to novel obesity-fighting compounds. —Coco Ballantyne

Have a Nice Trip

Man's best friend could be one of man's biggest hazards. Pets cause nearly an estimated 87,000 falls that need emergency room treatment every year in the U.S., according to the March 27 Morbidity and Mortality Weekly Report. A quarter of the tumbles happened when owners were walking their dogs, and twice as many women as men were hurt. Most injuries occurred in children and those 35 to 54 years old, but people 75 or older suffered the most serious damage. —Jordan Lite

Eggs Not Over Easy

Infertility treatments operate under the assumption that women are born with all the eggs they will ever have. But researchers reporting online April 14 in Nature Cell Biology claim they have found precursor stem cells in newborn and adult mice that could be prodded into producing new eggs. The scientists grew these cells in a petri dish and implanted them in mice engineered to be infertile. Although some of the mice subsequently gave birth, more studies will be needed to confirm the results. — Jordan Lite