Matthias Witte is professor of Social Work at the University of Mainz (Germany) since 2012. His specialist areas are Children and Youth Welfare and Transnational Social Support. In this context, he is also co-applicant of the DFG Research Training Group "Transnational Social Support". In 2008 he received his PhD at the University of Bielefeld with a dissertation on "Jugendliche in intensivpädagogischen Auslandsprojekten. Eine explorative Studie aus biografischer und sozialökologischer Sicht" [Youth in intensive educational foreign projects. An exploratory study of biographical and social environmental perspective; KG]. During and beyond his doctoral studies he passed several research stays at the Herzen State Pedagogical University of Russia in St. Petersburg as a guest. From 2008 to 2010 he worked as Associate Professor of Anthropology and Sociology of Sports at the University of Marburg (Germany). From 2010 to 2012 he was professor of Education of Adventure and Youth Research in Marburg.