More than 6 billion people worldwide (including almost 400 million in the United States) now carry mobile phones, which could be used to enhance mental and physical health, aCornell researcher proposed. Phones can give owners important information about their environment, offer advice and reminders to encourage healthy behavior and supply mountains of data to researchers, said Deborah Estrin, professor of computer science at Cornell NYC Tech in New York City. Estrin outlined her vision for "mobile health" in the presentation "Transforming Health Care Through Mobile Platforms," part of the symposium Smart Phones, Smart Devices, Social Networks, and Smart Health Care, at the 2013 Annual Meeting of the American Association for the Advancement of Science in Boston. The symposium, chaired by Google vice president Vinton Cerf, explored how emerging "net-centric societies" will transform the health care landscape. "We can leverage the power and ubiquity of mobile and cloud technologies to assist individuals, clinicians and researchers in monitoring and managing symptoms, side effects and treatment outside the clinical setting; and to address the lifestyle factors that can bring on or exacerbate health conditions," Estrin said. Health-enhancing applications of mobile devices might include diet and exercise tracking, medication reminders, monitoring of social and environmental stress and the formation of online support groups. As examples, Estrin cites PTSD Coach, developed by the Department of Defense and the Veteran's Administration to help veterans cope with post-traumatic stress disorder symptoms; mobile reporting from a diabetic's glucose meter; and the Fitbit wireless activity tracker.