Marni SommerMarni Sommer, DrPH, MSN, RN, is a Professor at the Mailman School of Public Health, Columbia University. Her areas of expertise include conducting participatory research with adolescents, understanding and promoting healthy transitions to adulthood, he intersection of public health and education, gender and sexual health, and the implementation and evaluation of adolescent-focused interventions. Dr. Sommer's current research focuses on the intersections of gender, health and education for girls and boys transitioning into adulthood around the world. Dr. Sommer has been working in global health for twenty-four years. Her research with girls in Tanzania formed the basis of the original book project. She continues to conduct research and advocacy on puberty, periods, and education globally. She founded Grow and Know, Inc. in 2010. Read More Read Less