Reuters: U.S. Defense Secretary Ash Carter, keen to expand the number of women and minorities in military leadership, will endorse “Lean In” discussion groups sparked by Facebook COO Sheryl Sandberg’s bestselling book. Carter and Sandberg will meet at the Pentagon with 15 women from all ranks and military services who already lead Lean In groups, followed by a news conference, where Carter will promote creation of more such groups, at government facilities and even during working hours.