John David, 73, teaches an exercise class called PACE to seniors at the 92nd Street Y in New York City. The former TV producer says he has finally found his true calling.
Shiho Fukada for NPR
Tunisian soldiers stand guard as a woman holds up a poster featuring opposition leader Chokri Belaid during his funeral procession in a suburb of Tunis on Feb. 8. Belaid's assassination has laid bare the political rifts in post-revolutionary Tunisia.
Fethi Belaid/AFP/Getty Images
A sockeye salmon that was caught from the research vessel Miss Delta off the coast of Vancouver is examined. The MSC has certified the fish as "sustainable" even though there is concern from scientists and environmentalists.
Brett Beadle for NPR
Jack Lew testifies before a House budget panel in 2011. The Senate Finance Committee is scheduled to consider Lew's nomination to be Treasury secretary on Wednesday.
J. Scott Applewhite/AP
Jerry Grymek, doggie concierge at the Hotel Pennsylvania in Manhattan, hands a treat to Rennet, a 10-week-old French bulldog. Rennet came to the hotel from Pennsylvania ahead of the 137th Westminster Kennel Club Dog Show.
Lam Thuy Vo/NPR
Notice anything unusual about this lung scan? Harvard researchers found that 83 percent of radiologists didn't notice the gorilla in the top right portion of this image.
Trafton Drew and Jeremy Wolfe
Dan Auerbach of The Black Keys performs in England last August. Along with five nominations for his band, Auerbach is nominated for Producer of the Year, Non-Classical division.
Simone Joyner/Getty Images