A string of bombings struck Baghdad today and left at least 30 people dead. It was the most violent day the city has seen in close to a month.

As The New York Times points out, while this kind of violence is common in the country, today's attacks were "a reminder, after weeks of relative calm, that an organized insurgency remained active."

Activity cuts the risk of Alzheimer's disease and slows cognitive decline, even in the very old, according to a new study.

There's been plenty of evidence for the "use it or lose it" theory of brain capacity. But this study is one of the first to show that activity of all sorts benefits people over age 80, even if they're not "exercising".

The DREAM Act calls for a path to citizenship for some undocumented students. In the past, Republicans have opposed versions of the bill, but some prominent figures like former U.S. Attorney General Alberto Gonzales say the GOP needs to find its own voice on the issue. He speaks with host Michel Martin.

Think flossing and brushing is helping to fight off heart disease and stroke? Think again.

An expert panel of dentists and cardiologists, writing in the American Heart Association journal Circulation, says there is no evidence that treating or preventing gum disease has any direct effect on heart health.

That's a big turnaround. For the past decade, the medical establishment has been telling people that cardiovascular disease can be caused by poor oral hygiene. Why the change?

Here’s an image you usually don’t see without the help of Photoshop: two-headed fish. Pictures of deformed baby trout with two heads show up in a study of creeks in a remote part of southeast Idaho. The study examined the effects of a contaminant called selenium. It comes from a nearby mine owned by the agribusiness giant, J.R. Simplot. Critics say the two-headed trout have implications beyond a couple of Idaho creeks. Jessica Robinson reports.

In a letter to the United Nations Security Council, Secretary General Ban Ki-moon says the Syrian government is not living up to its end of the bargain on a week-old cease-fire deal.

Ban says the government has failed to keep its pledge to withdraw troops and heavy weapons from cities, but adds that he still thinks there is "opportunity for progress."

The Secretary General's letter comes as the U.N. and Syria apparently worked out details of an observer mission to monitor the shaky deal meant to end more than a year of bloodshed that has killed an estimated 9,000 people.