Institute for Genomics and Bioinformatics, Department of Information and Computer Science, University of California, Irvine, Irvine, CA 92697-3425, USA. gpollast@ics.uci.edu|Institute for Genomics and Bioinformatics, Department of Information and Computer Science, University of California, Irvine, Irvine, CA 92697-3425, USA. gpollast@ics.uci.edu