Complex sentence: Even long after Ruiz's appointment, however, Americans and other nationals still constituted a considerable portion in the University's faculty, and up to the present, American and foreign visiting professors are still regularly assigned in specialized areas.
Split into simpler sentences: Even long after Ruiz's appointment, however, Americans and other nationals still constituted a considerable portion of the faculty. Up to the present, American and foreign visiting professors are still regularly assigned in specialized areas.