More than a month after Twin Cities hospitals and nurses settled their most bitter contract dispute in recent history, a similar battle is playing out in Duluth. Some 1,320 nurses who work for St. Mary's Medical Center, SMDC Medical Center and St. Luke's Hospital in Duluth are set to vote today whether to ratify a three-year contract or stage a one-day walkout. The Minnesota Nurses Association is recommending against ratifying the contract because it does not include its proposed language on staffing. As in the Twin Cities, the nurses say the biggest issue is making sure there are enough registered nurses to care for patients in the hospitals. Patients these days come in sicker yet stay for shorter periods, making each hospitalization more intense than in previous years, said Pam Hyopponen, a member of the nurses' negotiating team at St. Luke's.