He played a prominent leadership role for the Department of Energy's development multi-disciplinary program in advanced computational science, SciDAC (Scientific Discovery through Advanced Computing). He is currently the Director of the Plasma Science Advanced Computing Institute for DOE's Fusion Energy Sciences Program. In research activities, he is internationally recognized for his leading role in developing the requisite kinetic formalism as well as the associated computational applications dealing with electromagnetic plasma behavior in complex geometries. He has over 200 publications (including more than 130 papers in peer-reviewed journals such as Science, Phys. Rev. Letters, Physics of Plasmas, etc.) and has presented more than 40 invited talks at major conferences and prominent venues. He has contributed strongly to teaching and research training in Princeton University's Department of Astrophysical Sciences for over 20 years and has supervised numerous successful Ph.D. students, who have gone on to highly productive scientific careers. Examples include recipients of the prestigious Presidential Early Career Award for Scientists and Engineers in November, 2000 and in June, 2005.