Talk of the Nation

The Mississippi River anchors one of the world's largest watersheds and is a vital waterway for transporting coal, grain and construction materials to domestic and foreign markets. Millions rely on the river for drinking water, and it is a rich fish and wildlife habitat and resource for recreation.

President Obama and his Republican challenger Mitt Romney face off in Denver Wednesday for the first of three presidential debates. The president continues to hold a slight lead in many swing states, but Romney's been able to close the gap in the weeks since the conventions.

Over the last few years, singer-songwriter Mary Chapin Carpenter's life has been drastically transformed. In 2007, she suffered a life-threatening pulmonary embolism. Her marriage ended soon after, and then her father died. She channeled her grief from those experiences into Ashes and Roses.

Arnold Schwarzenegger has lived a long life in just 65 years, from poor immigrant to giant bodybuilder, from Hollywood action star to governor of California. He recounts it all — his successes and failures, his dreams and challenges — in his new autobiography, Total Recall.

NPR's David Green reads letters from listeners about previous show topics, including the new look of school lunches and the challenges and upsides of living with siblings who have intellectual disabilities.

With the presidential election a month away, the Court may soon weigh in on several contentious cases. Los Angeles Times Supreme Court correspondent David Savage talks about the upcoming session and whether the Court can insulate itself from the heat of this political season.

Elections in Georgia, Ukraine and Lithuania are being closely watched in the West as a test of whether former Soviet states will shift closer to Russia. Russian president Vladimir Putin, for his part, has made political, economic and security reintegration of former Soviet republics a priority.

The Oakland A's are headed to the playoffs for the first time in six years, and Washington's Nationals brought the pennant home for the first time since the Senators did it back in 1933. NPR's Mike Pesca talks about the surprises, the end of the baseball season and the outlook for the playoffs.

Bill Pullman enjoyed a star turn as the president of the United States in Independence Day. And in an upcoming NBC show, 1600 Penn, he's back in the White House. Pullman talks about his reputation as Hollywood's "everyman," his return to the presidency and his new film, Bringing Up Bobby.

Historic shops in Syria's largest city burned as rebels and government fighters continue to battle for control of Aleppo. Activists estimate 30,000 people have been killed so far. NPR's Deborah Amos and Andrew Tabler of the Washington Institute for Near East Policy weigh in on the crisis in Syria.

Decoding the information in DNA may soon be as routine as checking blood pressure. Recent advances make it possible to spell out a person's complete genetic code in a matter of weeks, for roughly the cost of an MRI. NPR's Rob Stein explains the rewards and risks of complete genome sequencing.

NPR's Ari Shapiro spent a week in one city in a battleground state, Colorado Springs, where campaign spending has tripled since 2008. He discovered how it's changing, and the campaign strategy behind targeting specific ads for specific markets in hopes of winning over undecided voters.

The Snake River area near Boise, Idaho has one of the world's highest concentrations of nesting raptors. Biologists Mark Fuller, Julie Heath & Chris Parish join Ira Flatow for a look at raptor biology, and the threats the birds are facing. Plus, bringing back the California condor.

Mammoths and saber-toothed cats may be the most famous beasts of the Ice Age. But they shared the prairie with horses and camels, too--both of which evolved in North America and crossed the ice bridge into Eurasia, before disappearing here. Matthew Kohn and Christopher Hill talk about the lesser-known fauna of the Ice Age.

When police find DNA at a crime scene, the amount and how it's handled are crucial components in solving a case. Greg Hampikian, Director of the Idaho Innocence Project, discusses the use and misuse of DNA analysis, and why he says all DNA evidence is not created equal.