This week, hosts Mark Masselli and Margaret Flinter speak with Dr. Rishi Manchanda, Founder and President of HealthBegins, an online portal to link "upstreamists" - health clinicians working on solving the social and environmental determinants of health. He discusses his new book, The Upstream Doctors, in which he promotes a movement to develop a national force of "upstream" medical professionals dedicated to transforming health care at its source, where patients live, work and play.