[1] Univ Houston, Dept Biol & Biochem, Coll Nat Sci & Math, Houston, TX 77204 USA
[2] Univ Houston, Coll Educ, Dept Psychol Hlth & Learning Sci, Houston, TX 77204 USA
[3] Univ Texas Hlth Sci Ctr, Sch Publ Hlth, Dallas, TX 75390 USA
[4] UT Southwestern Harold C Simmons Comprehens Canc, Populat Sci & Canc Control Program, Dallas, TX 75390 USA