Impact Engine, a Chicago accelerator for for-profit businesses that address social and environmental challenges, announced its “Impact 3” cohort, which will feature six Chicago-based companies. The companies will spend 16 weeks building their businesses at the 1871 coworking center, where Impact Engine is based. http://www.chicagotribune.com/bluesky/originals/chi-impact-engine-new-class-bsi-20140911-story.html