作者单位:San Diego State Univ, Dept Comp Sci, 5500 Campanile Dr, San Diego, CA 92182 USA[1]Univ Fed Rio de Janeiro, Inst Biol, Dept Marine Biol, BR-21941902 Rio De Janeiro, Brazil[2]Katholieke Univ Leuven, Rega Inst, Dept Microbiol & Immunol, Herestr 49, B-3000 Leuven, Belgium[3]