A police officer runs following a car bomb attack on police patrol trucks July 15 in the border city of Ciudad Juarez, Mexico. The Juarez cartel claimed responsibility for the blast, which killed three people and marked an unprecedented escalation in Mexico's drug war. AP hide caption

Officials say a fleet of 3,000 cars is planned for next year's start of Autolib, Paris' electric vehicle-sharing system. faberNovel2009 via Flickr hide caption

We know relatively little about whether the pain that follows a loss is, in a health sense, necessary. iStockphoto.com hide caption

Jamis MacNiven bought Buck's Restaurant in 1991; it quickly became a hangout for venture capitalists from around Woodside, Calif. John McChesney/NPR hide caption

Om Nom Nom: As we began to shy away from eating primarily fruit, leaves and nuts and began eating meat, our brains grew. We developed the capacity to use tools, so our need for large, sharp teeth and big grinders waned. From left, a cast of teeth from a chimpanzee, Australopithecus afarensis and a modern human. William Kimbel/Institute of Human Origins hide caption

Members of South Sudan's "Arrow Boys" patrol on May 22. The group formed in Western Equatoria to protect villagers from attacks by the Lord's Resistance Army -- a rebel group organized in Uganda 20 years ago. Trevor Snapp for NPR hide caption

The Notorious B.I.G.'s first rap name was MC CWest. Bad Boy Entertainment hide caption