Most of the contributors to this volume attended a workshop held in Cambridge, UK in late August 2014. The workshop was sponsored by the Gulf Research Center (GRC). Special thanks go to Dr. Abdulaziz Sager, chairman of the GRC, Dr. Christian Koch, director, Sanya Kapasi, administration manager, and Ms. Elsa Courdier, administrator. Also I would like to thank Kai Henning Gerlach and Dagmar Konrad from Gerlach Press. After the workshop I worked closely with all the contributors to upgrade and revise the papers. I cannot thank them enough for their valuable contributions. Finally would like to thank my assistant Ms. Alexandra Holden for her hard work.