University Medical Center in Tucson, Ariz.--the same hospital where Rep. Gabrielle Giffords is being treated--has sued the U.S. Department of Health and Human Services over how to calculate the number of residents at a teaching hospital for Medicare reimbursement, Bloomberg reports. Teaching hospitals can ask for more money from the government for the Medicare patients they treat, because such hospitals bear higher-than-average costs, the complaint said. The additional reimbursement is tied to the number of residents. Article