by Larry Klein; Brad Pitt; Sheldon Mirowitz; Mike Beckham; Sarah Holt; Gail Willumsen; Andrew Young; Tabitha Jackson; Rob Whittlesey; Jimmy Carter; David Brancaccio; Philip J Hilts; WGBH (Television station : Boston, Mass.). Science Unit.; Vulcan Productions.; WGBH Educational Foundation.; Johns Hopkins Bloomberg School of Public Health.; Circus Productions.; Holt Productions.; Gemini Productions.; Archipelago Films.; RCSR Productions.; WGBH Video (Firm);