Affiliation: | aDepartment of Mathematics and Statistics, McGill University, Montréal, Canada bDepartment of Computer Science, University of California, Irvine, California, USA cMcGill Centre for Bioinformatics, School of Computer Science, McGill University, Montréal, Canada dDepartament de Matemàtica Aplicada II, Universitat Politècnica de Catalunya, Barcelona, Spain |