Researchers work permit for italy !!

Hi does anyone knows about work permit for researchers ?
what if the work permit for researchers has been requested outside decrete flussi ( ie outside quota limits ) then can that person change his job ??

can such work permits issued for sabordinate employements be renewed using another jobs contracts ?

what happens in these cases ? do we have to go back and reapply for another work permit if we are interested in changing jobs ?

rishi raj