Nurses at Morton Hospital and Medical Center in Taunton, MA, say they are contemplating a strike after months of meetings and stalled contract negotiations with hospital management. The Massachusetts Nurses Association, which represents more than 400 nurses, physical therapists, and other staff at Morton, wants to end mandatory overtime shifts that require some employees to work more than 12 hours. The union is also fighting an effort to switch nurses' traditional pension plans to contribution-based funds, primarily 401(k) plans. David Schildmeier, a spokesman for the nurses group, said the hospital has threatened to change the plans by March 31, despite the ongoing contract talks.