A python embryo turns its leg cells into a pair of penises. Researchers now believe that signals from the embryonic gut trigger the development of the penis in many different species. Patrick Tschopp/Harvard Medical School/Department of Genetics hide caption

itoggle caption Patrick Tschopp/Harvard Medical School/Department of Genetics

David Roberts says the Cyber-Enhanced Working Dog harness will allow humans to monitor dogs' physical and emotional states remotely, such as in search and rescue operations. Becky Kirkland/North Carolina State University hide caption

itoggle caption Becky Kirkland/North Carolina State University

In 49 U.S. states, spotting the squished disc in this spinal MRI is still much easier than learning the price of the MRI in advance. AWelshLad/iStockphoto hide caption

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Saah Exco was found alone on a beach in Liberia's West Point slum, naked and abandoned and likely an Ebola victim.Research suggests the story of one needy individual motivates charitable donors more than statistics about millions of sufferers. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Researchers at Cold Spring Harbor Laboratory say their new genetic toolkit to improve tomato yield without compromising flavor can be used in all varieties, from plum to cherry. Courtesy of Zach Lippman/Cold Spring Harbor Laboratory hide caption

itoggle caption Courtesy of Zach Lippman/Cold Spring Harbor Laboratory

Strontium atoms floating in the center of this photo are the heart of the world's most precise clock. The clock is so exact that it can detect tiny shifts in the flow of time itself. Courtesy of the Ye group and Brad Baxley/JILA hide caption

itoggle caption Courtesy of the Ye group and Brad Baxley/JILA

Stringy particles of Ebola virus (blue) bud from a chronically infected cell (yellow-green) in this colorized, scanning electron micrograph. NIAID/Science Source hide caption

itoggle caption NIAID/Science Source

Don't look for leading Ebola researchers at the Sheraton New Orleans. Louisiana health officials told doctors and scientists who have been in West Africa not to come to a medical meeting in town. Prayitno/Flickr hide caption

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Magnified 25,000 times, this digitally colorized scanning electron micrograph shows Ebola virus particles (green) budding from an infected cell (blue). CDC/NIAD hide caption

itoggle caption CDC/NIAD

After a hard day of bruising battle, ancient gladiators reached for a post-workout drink, according to an ancient account. New research backs that up. Stefano Bianchetti/Corbis hide caption

itoggle caption Stefano Bianchetti/Corbis

Patients with certain kinds of brain damage can wind up with locked-in syndrome: they may be able to think just fine, but are unable to communicate their thoughts to others. A recently published case study shows that a non-invasive brain-computer interface can help. iStockphoto hide caption

itoggle caption iStockphoto