Department of Mathematics and Computer Science, University of Southern Denmark, Funen, Denmark, Department of Computer Science, Brown University, Providence, Rhode Island, United States of America, Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America.|Department of Computer Science, Brown University, Providence, Rhode Island, United States of America, Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America.|Department of Computer Science, Brown University, Providence, Rhode Island, United States of America, Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America.|Department of Computer Science, Brown University, Providence, Rhode Island, United States of America.