Julien Brachet (France) is researcher at the Institut de Recherche pour le Développement (UMR 201 Développement & Sociétés, IRD - Université Paris 1 Panthéon-Sorbonne). He obtained his Ph.D. in geography at the University of Paris 1 Panthéon-Sorbonne in 2007. His research focuses on mobilities to and through the Central Sahara, in particular in northern Niger, where he studies migration networks, transport systems and trade between sub-Saharan and northern Africa. Current research focuses on shifting spatial boundaries and strategies that allow local people to adapt to a general context marked by the growing severity of international policies regarding movement and migration. He has published several articles in French and English on these topics and a book: Migrations transsahariennes. Vers un désert cosmopolite et morcelé (Niger) (Paris: Éditions du Croquant, 2009).