Katherine Unger Baillie

Libraries hold treasures. Yet not everyone has the time or opportunity to stroll regularly through the stacks to uncover these buried gems.

The goal of a hospital it to make patients well, but hospital-acquired infections can result in just the opposite. That’s why infection control has become a top priority in medical facilities — and, increasingly, in veterinary settings as well.

PHILADELPHIA — Two studies led by scientists from the University of Pennsylvania and National Geographic’s Genographic Project reveal new information about the migration patterns of the first humans to settle the Americas.

The Mississippi, North America’s largest river and the fourth-largest river in the world, is a powerful natural force. So powerful, it appears, that the 2010 Gulf of Mexico oil spill changed course due to the river’s outflow, sparing the Louisiana coast from worse oil pollution than it might have otherwise experienced.

PHILADELPHIA — Tracy L.

PHILADELPHIA — When the Deepwater Horizon drilling rig exploded April 20, 2010, residents feared that their Gulf of Mexico shores would be inundated with oil. And while many wetland habitats and wildlife were oiled during the three-month leak, the environmental damage to coastal Louisiana was less than many expected, in part because much of the crude never made it to the coast.

KENNETT SQUARE — It’s a quaint image: a rural vet in a pick-up truck driving down a country lane to treat a sick cow or horse.

PHILADELPHIA — A $25 million gift to the University of Pennsylvania from alumni Mindy and Jon Gray will establish a center focused on the treatment and prevention of cancers associated with hereditary BRCA mutations.

Pygmies of western Africa are short—really short. On average, Pygmy men stand just 4’11” tall. Yet their neighbors, a group known as the Bantus, are of average height.

PHILADELPHIA — Nancy Bonini, Gideon Dreyfuss and Beatrice H.