Terry Gross

The name of former anti-war activist William Ayers was brought up twice in an attempt to discredit Barack Obama during the recent presidential campaign — first by Hillary Clinton, and then by the McCain campaign.

What if you could diagnose cancer just by smelling it? Dr. William Hanson explains the 'Diag-Nose' — an electronic nose that can do just that — plus other medical technologies that he says will change our lives.

Dr. Jim Withers founded Operation Safety Net after he began making "house calls" under bridges in Pittsburgh, Pa. Now it's one of the nation's first full-time street medicine programs.