Lost in the contract dispute between Clark County and the Service Employees International Union are real concerns that wages for the unionized nurses at University Medical Center are far below those of private hospitals. The result, the argument goes, is that private hospitals easily poach UMC's nurses by offering higher pay. That disparity in pay might now be addressed.Two weeks ago, Clark County commissioners, who are also UMC's board of trustees, accepted a report from the hospital on the income disparity. And they gave the hospital approval to increase the pay range for registered nurses.