Burch named chairman of UM Medical SystemAfter recent strife that included the resignation of one-third of its board, the leaders of the University of Maryland Medical System this week unanimously approved a new chairman. The board voted for Stephen A. Burch, former president of Comcast Corp.'s Mid-Atlantic division, to take over the chairmanship from Maryland House of Delegates Speaker Michael E. Busch, who had been named interim chairman when John C. Erickson resigned and other directors followed. The system, which oversees hospitals in Baltimore and throughout the state, had been beset by conflicts among doctors, the university and other stakeholders, and over Gov. Martin O'Malley's decision to appoint new members to the board without its input. Burch rejoined the board this summer after spending several years as CEO of British television and telephony company Virgin Media Inc.