Complex sentence: After earning her Ph.D. from Columbia in 1979, Barton held post-doctoral appointments at Bell Labs and Yale University, where she worked with R.G. Shulman She earned tenure at Columbia University in the 1980s.
Split into simpler sentences: After earning her Ph.D. from Columbia in 1979, she held post-doctoral appointments at Bell Labs and Yale University, where she worked with R.G. Shulman. Barton earned tenure at Columbia University in the 1980s.