Computer Science Department, Worcester Polytechnic Institute, 100 Institute Rd, Worcester, 01609, USA. tmdefreitas@wpi.edu.|Department of Mathematics and Statistics, University of Massachusetts, Amherst, 710 N. Pleasant St, Amherst, 01003, USA. hsaddiki@umass.edu.|Program in Bioinformatics and Computational Biology, 100 Institute Rd, Worcester, 01609, USA. flaherty@math.umass.edu.