With the finish line in sight, Board of Regents District 9 candidates Ron Knecht and Michon Mackedon have turned up the heat in their race for the nonpartisan seat as they sparred this week over details of a recent political advertisement.Mackedon, the challenger from Fallon, alleges in campaign ads that Knecht was fired from his position as senior economist by the state Public Utilities Commission for "violating policies that included falsifying his timesheet and conducting political outside employment activities during work hours, according to an investigative report."Knecht, who was elected to the Board of Regents in 2006, was terminated by …