Program of Bioinformatics and Computational Biology and Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011, USA.|Program of Bioinformatics and Computational Biology and Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011, USA.|Program of Bioinformatics and Computational Biology and Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011, USA.