Affiliation: | 1 Radiation Effects Research Foundation, 5-2 Hijiyama Park, Hiroshima 732-0815, Japan pierce{at}rerf.or.jp, 2 Radiobiological Institute, Ludwig-Maximilians University, Schillerstrasse 42, Munich 80336, Germany amk.sbi{at}lrz.uni-muenchen.de |