Institution: | (1) Department of Mathematics, Howard University, Washington DC, USA;(2) Department of Mathematics, University of Pittsburgh, 15260 Pittsburgh, PA, USA;(3) Department of Computer Science, Virginia Polytechnic Institute and State University, 24061 Blacksburg, VA, USA;(4) Laboratory of Investigative Cytology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, 10021 New York, NY, USA |