The founder and former chief executive of troubled Bixby Energy, an alternative energy startup, will appear in U.S. District Court in St. Paul this afternoon after being arrested this morning by federal agents. Bob Walker, also the retired founder of mattress maker Select Comfort Corp., is scheduled to appear before Magistrate Judge Janie S. Mayeron at 2 p.m., Jeanne Cooney, community relations director for the U.S. Attorney's office said today. The charges against Walker will be revealed in court, Cooney said. Last Wednesday, Ramsey-based Bixby Energy admitted to defrauding investors of between $2.5 million and $7 million and agreed to...