Workers at Rhode Island Hospital are authorizing a ten day strike notice against facility owner Lifespan Corporation.  Teamsters Local 251 represents more than two-thousand workers at the hospital, including nurses, maintenance and food service employees.  The union is seeking better pay, health insurance, retirement benefits and layoff protection for the workers.  The hospital says the union's demands are not sustainable, but they remain optimistic that a deal can be reached to avert a strike.