1. Asst. Prof., School of Public Health, Univ. of Illinois at Chicago, 2121 W. Taylor St., Chicago, IL. 60612. E-mail: anli@uic.edu
2. Grad. Res. Asst., School of Public Health, University of Illinois at Chicago, 2121 W. Taylor St., Chicago, IL.
3. Assoc. Prof., Dept. of Civ. and Mat. Engrg., University of Illinois at Chicago, 842 W. Taylor St., Chicago, IL 60607.