1. Department of Geography; Durham University; Science Laboratories, South Road Durham DH1 3LE
2. Department of Science and Technology Policy; Institute of Geosciences, PO Box 6152; University of Campinas - UNICAMP; 13083-970 Campinas SP Brazil
3. Centre for Social Justice and Community Action; School of Applied Social Sciences; Durham University; Elvet Riverside 2, New Elvet Durham DH1 3JT