National and World News from NPR

During his trip to Detroit, yesterday, President Obama visited the Henry Ford Museum and had the opportunity to sit in the bus where in 1955 Rosa Parks refused to give up her seat to make way for a white customer. That moment sparked the Montgomery Bus Boycott and fueled the civil rights movement that made it possible for Barack Obama to become president.

Today, the White House's photographer Pete Souza tweeted a picture of the moment:

Florida Gov. Rick Scott appointed a task force on Thursday charged with reviewing the state's gun laws, including the so-called "stand your ground law," that came into controversial focus after the shooting death of Trayvon Martin.

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?