Berkeley Lab life scientist Björn Rydberg passed away unexpectedly on Dec. 11, 2011, at the age of 68. Rydberg, who was born in Sweden and received his Ph.D. in biophysics from Uppsala University, had been with the Life Sciences Division since 1990. He was internationally recognized as an expert in radiation-induced DNA strand breakage and rejoining, with special expertise in effects of high-LET particles such as those in galactic cosmic rays. He published more than 55 scientific papers and was an outstanding experimentalist with a deeply analytical approach to understanding the effects of ionizing radiation on mammalian cells. Go here to read an obituary written by his colleagues.