1. Bioinformatics Research Unit, Institute for Biomedical Technologies, National Research Council of Italy, Segrate, 20090 Milan, Italy
2. Bioinformatics and High Performance Computing Research Group (BIO-HPC), Computer Science Department, Universidad Católica San Antonio de Murcia (UCAM), 30107 Murcia, Spain
3. Department of Computer Science and Engineering, Center for Research Computing, University of Notre Dame, P.O. Box 539, Notre Dame, IN 46556, USA
4. Advanced Computing Systems and High Performance Computing Group, Institute of Applied Mathematics and Information Technologies, National Research Council of Italy, 16149 Genoa, Italy