Complex sentence: His brother, Dr. Herman Ausubel, was a professor of Victorian history at Columbia, and his nephew David P. Ausubel was a noted professor, educator, ethnographer, and a pioneer in cognitive educational psychology.
Split into simpler sentences: His brother, Dr. Herman Ausubel, was a professor of Victorian history at Columbia. His nephew David P. Ausubel became a noted professor, educator, ethnographer, and a pioneer in cognitive educational psychology.