Martin Seligman

Zellerbach Family Professor of Psychology & Director of the Positive Psychology Center at the University of Pennsylvania

Luis von Ahn

Founder and CEO of reCAPTCHA and Duolingo

Mark Zandi

Chief Economist of Moody's Analytics; Co-Founder of Economy.com

Julie Gerberding, MD

Infectious Disease Expert; Former Director of the U.S. Centers for Disease Control & Prevention (CDC)

Listen First, Treat Later: Dr. Julie Gerberding on the HIV Epidemic ...