Boston--CXO Media, a wholly owned subsidiary of b-to-b media giant IDG Corp., announced Wednesday it has reduced its work force by 16% because of the ad slump. The announcement came just one day after CXO shut its print version of Darwin. (The Web site will continue to operate.) The cutbacks include layoffs at both Darwin and CIO. In a statement, CXO Media CEO Joe Levy said: "We tried our best to find alternatives to this course of action but the market conditions and advertising recession left us no other choice."