Fuse has named Catherine Mullen, a former exec for rival musicvid cabler MTV, as its new exec VP and general manager.Mullen takes over for programming chief Rob Weiss, who ankled the cabler late last year. Weiss had been on the job for about a year and helped boost primetime ratings for the fledgling cabler by 26%. As G.M. at MTV U.K. and Ireland, Mullen brought “Total Request Live” to Leicester Square and turned around a five-year ratings decline. Mullen will oversee Fuse’s everyday operations and aim to broaden the station’s appeal in the young adult market. She will head all programming, marketing and development for the station as well as its digital sector, with an eye toward expanding Fuse’s online offerings.