Cases of Scientists and Technologists who became the Head of their Countries

I would like to collect cases of scientists who, in recent years, became heads (presidents, chancellors, prime ministers) of their countries. I need information from you, especially from countries in transition in all parts of the worid, including the newest and smallest country of Gronland (Greenland), and nearly technologizing parts of the world such as India and South Africa. A collection of such cases will be very useful for political and social policy makers.