1. a Departments of Community Medicine and Medicine , School Health Education Project of the National Heart and Blood Vessel Research and Demonstration Center at Baylor College of Medicine , Houston , Texas , USA
2. b Education Division , School Health Education Project of the National Heart and Blood Vessel Research and Demonstration Center at Baylor College of Medicine , Houston , Texas , USA
3. c Department of Community Medicine , School Health Education Project of the National Heart and Blood Vessel Research and Demonstration Center at Baylor College of Medicine , Houston , Texas , USA
4. d School Health Education Project of the Education Division. School Health Education Project of the National Heart and Blood Vessel Research and Demonstration Center at Baylor College of Medicine , Houston , Texas , USA
5. e Department of Health and Physical Education , Rice University , Houston , Texas , USA
6. f School Health Education Project of the National Heart and Blood Vessel Research and Demonstration Center at Baylor College of Medicine , Houston , Texas , USA