NPR News

If Rick Santorum has a lead on Mitt Romney in Ohio, it looks like it's not much of one. A new Quinnipiac University poll shows Santorum leading Romney by four percentage points, 35 percent to 31 percent.

With the margin of error at +/-4.3 points, the two top rivals for the Republican presidential nomination are essentially tied just days before Super Tuesday when voters in Ohio and nine other states take part in the presidential primary process.

Children are diagnosed with lead exposure only when their health is already endangered. Wouldn't it be better to prevent that danger instead? That's the goal of a project in the city of St. Louis that tests the homes of pregnant women and removes dangerous lead before babies were born.

That SWAT-team approach can reduce children's exposure to toxic lead, according to a new study.

Yelp surprised analysts today during its first hours of trading as a public company.

As the Seattle PI puts it, the user-review company's shares soared by as much as 60 percent in early trading. The stock opened at $22.01 a share and has hit a high of $25.10.

South Sudan gained independence in 2011, but it has been locked in a bitter conflict with its northern neighbor. Rep. Frank Wolf (R.-Va.) just returned from the area. He talks with host Michel Martin about what some observers are calling a humanitarian crisis, and what the U.S. can do to help.