Lisa Gersh, president and chief executive officer at Martha Stewart Living Omnimedia, is stepping down from her position, with a search for a successor already underway. Gersh joined the company in 2011 as president and chief operating officer, replacing Charles Koppelman as CEO in July of this year. Gersh will remain in her role during a transition period.

Dave Mevorah has been named national advertising director at Targeted Health Media, Time Inc.’s division focusing on pharma and other health-related advertisers. Mevorah had been sales director at Time’s Media Networks Inc. Targeted Health Media has also brought in Jennifer McDonald, naming her New York sales manager. McDonald also joins from MNI, where she was an account executive.

Michelle Smith has been promoted to senior director of product management at 24/7 Media, up from her previous position as director. The agency has also hired Sonjoy Ganguly as a senior director of product management, following a stint as director of product management at Deutsche Bank in New York.

Profero New York has named Veronica Villalpando group account director, working with the agency’s TRESemmé, Vonage and Macy’s accounts. Villalpando had been global account director at Ogilvy & Mather.

SiriusXM Radio has named Jim Meyer interim chief executive officer, replacing the outgoing Mel Karmazin. Meyer had been the radio company’s president of sales and operations.

ProPublica has made a number of moves, including promoting editor in chief Paul Steiger to executive chairman. Replacing Steiger as editor is former managing editor Stephen Engelberg, and replacing Engelberg as managing editor is former senior editor Robin Fields. Also at ProPublica, senior editor Eric Umansky has been promoted to assistant managing editor, a new position.

Aaron Finn has been named chief executive officer at the online advertising technology company AdReady, replacing Aaron Averbuch, who has become chief technology officer. Finn is a co-founder of the company and also serves as chairman of the board.

Michael Cleveland is starting a second stint as editor of The Cabinet Press in Milford, N.H., after previously editing the paper from 1996 to 2008. Cleveland rejoined the newspaper last year as a copy editor and reporter.

Universal Television has signed “30 Rock” executive producer Jack Burditt to a new two-year deal, under which he will develop new series. Burditt is also creator of ABC’s Tim Allen comedy “Last Man Standing.

Longtime ABC newsman Sam Donaldson was arrested for driving under the influence earlier this month in Lewes, Del., after failing a field sobriety test. Donaldson retired from full-time duty at ABC in 2009, although he still appears on “This Week” and on ABC News Radio.

BBC America has ordered a full season of “The Nerdist,” a comedy and variety show starring Chris Hardwick and based on his podcast of the same name. The show will air next year on the network’s Supernatural Saturday block, which is also hosted by Hardwick.

Tags: Aaron Averbuch, Aaron Finn, Chris Hardwick, Eric Umansky, Jack Burditt, Lisa Gersh, Michael Cleveland, Robin Fields, Sam Donaldson