1. a Human Resources Department , Texas A & M University , College Station , TX , 77843-1255 , USA
2. b Division of Health Education, Department of Health and Physical Education , Texas A&M University , USA
3. c Department of Health and Human Performance , University of Houston , USA
4. d Division of Allied Health Sciences, Department of Community Medicine , Baylor College of Medicine , USA
5. e Department of Community Medicine , Baylor College of Medicine , USA