BostonGlobe.com Political Headlines - May 12, 2014 May 13, 2014 Here are the top political headlines from BostonGlobe.com today: A time of the signs as Walsh’s name rises: In Mayor Walsh’s first four months, his name has been added to hundreds of pieces of public property. Andrew Ryan reports. Medical device stirs security concerns: Officials worry that the cesium chloride used in conventional blood irradiator machines could threaten public safety. Bryan Bender details the story. A fellow Democrat takes on John Tierney: Iraq veteran Seth Moulton is looking to beat the congressman in the Democratic primary. Stephanie Ebbert reports. Fisher’s ballot fight exposes GOP haplessness: Somehow the Mass. Republican Party has become twisted up over somebody named Mark Fisher. Adrian Walker details the latest. Warren Tolman gives up investment in betting game firm: The attorney general hopeful was involved with a company known as Fast Strike Games. Joshua Miller reports.