(Duluth, MN)  --  There's another round of negotiations in Duluth today as nurses try to avoid a one-day strike.  Talks between the nurses union and SMDC broke off last Wednesday with no reported progress.  Now the union is back at the bargaining table with St. Luke's Hospital under the eye of a federal mediator.  St. Luke's officials are only saying they hope an agreement can be reached today.  The main issue appears to be nurse staffing levels.  The nurses want more flexibility in situations where they feel they're being asked to take care of too many patients.  The hospitals have responded that patient care is their top priority.  The week before last, the nurses authorized a one-day strike which their union leaders have not yet called.