1 Cytogenetics Biodosimetry Laboratory, Radiation Emergency Assistance Center and Training Site, Oak Ridge Institute for Science and Education, Oak Ridge Associated Universities, Oak Ridge, TN, USA.
2 Department of Ecological and Biological Sciences, University of Tuscia, VIterbo, Italy.
3 Department of Genetics, Universitat Autonoma de Barcelona, Barcelona, Spain and Genetics Department, Hospital de Sant Pau, Barcelona, Spain.
4 Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. Electronic address: phsmph@nus.edu.sg.