Check this out for those in engineering

Doctorate in Electrical and Computer Engineering | Office of Graduate Studies | University of Missouri

To be accepted outright by the director of graduate studies (DGS), the student needs to have an MS degree in either Electrical Engineering or Computer Engineering. Students who meet the academic requirements but have degrees in other engineering or science disciplines can be accepted into the PhD program by the Graduate Program Committee (GPC).

http://gradstudies.missouri.edu/academics/programs/electrical-and-computer-engineering/doctorate.php