And the layoffs begin -- a source tells us the first person to be let go from the Chronicle in their 25% reduction-in-staff campaign is managing editor Robert "Rosey" Rosenthal. We got the news confirmed by Friend of SFist and Chron Blogging/Interactive Editor Eve Batey, who says: It's no secret that we're losing at least 20 managers, but I was still shocked to hear that Rosey would be leaving. The instant rapport I had with......