[1] Tufts Univ, Dept Mol Biol & Microbiol, Boston, MA 02111 USA
[2] Frederick Natl Lab Canc Res, Canc Res Technol Program, Frederick, MD USA
[3] Frederick Natl Lab Canc Res, Adv Biomed Computat Sci, Frederick, MD USA
[4] Univ Pittsburgh, Dept Med, Div Infect Dis, Pittsburgh, PA USA
[5] Univ N Carolina, Dept Med, Chapel Hill, NC 27515 USA
[6] NCI Frederick, HIV Dynam & Replicat Program, Frederick, MD USA