Many of the thousands of troops who suffered traumatic brain injuries in Iraq and Afghanistan are at risk of long-term health problems including depression and Alzheimer's-like symptoms, but it's impossible to predict how high those risks are, researchers say.
Measles deaths worldwide declined dramatically to about 200,000 a year, continuing a successful trend, global health authorities reported Thursday.
A conservation group is going to court to force the federal government to consider adding the Pacific walrus to the list of threatened species.