Program in Computational Biology and Bioinformatics, Department of Computer Science, Center for Systems Biology, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA. michael.mayhew@duke.edu|Program in Computational Biology and Bioinformatics, Department of Computer Science, Center for Systems Biology, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA. michael.mayhew@duke.edu|Program in Computational Biology and Bioinformatics, Department of Computer Science, Center for Systems Biology, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA. michael.mayhew@duke.edu|Program in Computational Biology and Bioinformatics, Department of Computer Science, Center for Systems Biology, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA. michael.mayhew@duke.edu|Program in Computational Biology and Bioinformatics, Department of Computer Science, Center for Systems Biology, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA. michael.mayhew@duke.edu