The board is authorized to execute and carry out with any entity or institution affiliation or coordinating agreements that are reasonably necessary or desirable for the conduct and operation of professional schools of the first class, not in conflict with § 74.401 of this code, and the board is specifically authorized to make joint appointments in other institutions under its governance, the salary of any such person who receives a joint appointment to be apportioned to the appointing institutions on the basis of services rendered.