Department of Mathematics and Statistics and Center for Biomedical Research, Oakland University, Rochester, Michigan, USA.|Department of Mathematics and Statistics and Center for Biomedical Research, Oakland University, Rochester, Michigan, USA.|Department of Mathematics and Statistics and Center for Biomedical Research, Oakland University, Rochester, Michigan, USA.|Department of Mathematics and Statistics and Center for Biomedical Research, Oakland University, Rochester, Michigan, USA.|Department of Mathematics and Statistics and Center for Biomedical Research, Oakland University, Rochester, Michigan, USA.|Department of Mathematics and Statistics and Center for Biomedical Research, Oakland University, Rochester, Michigan, USA.|Department of Mathematics and Statistics and Center for Biomedical Research, Oakland University, Rochester, Michigan, USA.