Talk of the Nation on HD-2

The viruses, spam and malware that have plagued desktop computers for years now increasingly threaten mobile smartphones, as well. More text messages now deliver scams and a growing number of malicious apps install spyware, target personal information and attempt to charge users hidden fees.

Mitt Romney eked out a victory in Ohio's Super Tuesday primary. It was the closest of ten races, and the most closely watched. Rick Santorum came in second. Newt Gingrich took his home state of Georgia, Romney won six in all, and Santorum kept his campaign alive by winning three.

Talk of the Nation listeners wrote to the show to share their insights on previous show topics, including genetic testing, affirmative action, the source and practice of patience, and interracial marriage.

Overcrowded prisons already coping with budget pressures face a new challenge: The growing needs of an aging inmate population. With limited state budgets, prison setups, and facilities, prison officials are trying new ways to provide care and, in some cases, opting to release inmates early.

President Obama recently said, "Iran's leaders should understand that I do not have a policy of containment; I have a policy to prevent Iran from obtaining a nuclear weapon." Some say containment represents a viable option against Iran, but others argue that Cold War strategies do not apply to Iran.

Adult children caring for elderly parents may feel guilty, isolated and resentful. But some parents being cared for do too. Dr. Lillian Rubin knows that struggle well, as she has found herself at odds with her well-meaning daughter over what her daughter wants for her, and what she actually needs.

A growing field of medical research aims to pinpoint exactly why pets can make us happier and healthier. Some studies show that animal interaction can increase a person's level of oxytocin, a hormone associated with love and trust. And the animals also benefit from positive human interaction.

Syndicated radio host Rush Limbaugh called a Georgetown student a "prostitute" and a "slut" after she testified before a Senate committee and called for federal health care coverage to include the cost of contraception. Limbaugh apologized, but it has prompted a re-examination of the term, "slut."

On stage, Teller, half of the magician team of Penn & Teller, rarely says a word.

But now he's talking, explaining how magicians harness scientific research on deception to trick audiences into falling for their illusions. And their work, in turn, makes them interesting to brain researchers.

The human brain craves predictability, according to neuroscientists, and when politicians appear to flip-flop, our brains don't like it. Often, we feel betrayed. NPR science correspondents Jon Hamilton, Alix Spiegel and Shankar Vedantam talk about why we're hard-wired to appreciate consistency.