David Fillmore , Ph.D. Software Developer II Dr. Fillmore received a B.A. in Physics from the University of California, Santa Cruz, with an emphasis in high energy particle physics, in 1995, and a Ph.D. in Astrophysics and Planetary Science from the University of Colorado in 2006. His doctoral studies focused on modeling the radiation balance of the Earth's climate system and its modulation by natural and anthropogenic aerosols. txcorp