Institute for Systems Theory and Automatic Control, Pfaffenwaldring 9, 70550 Stuttgart, Germany. andrei.kramer@ist.uni-stuttgart.de.|Institute for Systems Theory and Automatic Control, Pfaffenwaldring 9, 70550 Stuttgart, Germany. andrei.kramer@ist.uni-stuttgart.de.|Division of Bioinformatics, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido 001-0020, Japan. itok@czc.hokudai.ac.jp.