Assistant professor, Kermanshah University of Medical Sciences, Kermanshah, Iran

Universidad Nacional Autónoma de México

Wageningen University, Norwegian University of Life Sciences

Professor of science and environmental education, University College London

University of Queensland, Tourism Discipline, Business School.

Professor, CSU Distinguished Teaching Scholar, Colorado State University

Dean Emeritus, Woods Hole Oceanographic Institution

University of Antwerp

Professor (Emeritus) of Ecology and Environmental Science,University of Mount Union

UFMG