Former Propaganda director Nzingha Stewart has signed with David Naylor & Associates/DNA for spot and music video representation. ... In Boston, graphic and interactive design firm Paratore & Hartshorn has merged with ad agency Gearon Hoffman. The firm's prinicpals, Vince Paratore and Mark Hartshorn, both take on the title senior designer at the agency. ... Lisa Cleff, formerly of Attik/San Francisco, has joined Manhattan's Riot Design as head of business development. Cleff's appointment follows the promotion of Jeremy Hollister to creative director.