[1] Univ Politecn Madrid, Med Informat Grp, Artificial Intelligence Lab, Sch Comp Sci, E-28660 Madrid, Spain
[2] Inst Hlth Carlos III, Bioinformat Unit, Madrid, Spain
[3] King Juan Carlos Univ, Madrid, Spain
[4] European Commiss, Directorate Gen Informat Soc, Brussels, Belgium
[5] Rutgers State Univ, Dept Comp Sci, Piscataway, NJ 08855 USA