"Visiting scientists enrich the University of Kassel".

"Guest researchers enrich the University of Kassel and are an important part of the internationalization concept. I myself have already had five Humboldtians as guests, one of them currently. A sixth application is in the review phase. Bringing guest researchers to Kassel and spending a research period abroad as a professor at the university broadens your cultural horizons and shows you other working methods and situations. In the natural sciences, this opportunity is already well used. When I spent a year in the USA as a fellow of the Alexander von Humboldt Foundation in 1990, it not only helped me a lot for my future career, but also for my family, and many decisions would have been different without this experience abroad. Even though I only became the host of a scientist from Cameroon by chance in 1997, looking back I see it as a lucky coincidence. My interest in the African continent has broadened over the years, and in my opinion, this part of the world still needs an enormous amount of promotion.

I regularly host guests, mainly from West Africa. I also frequently visit Cameroon to support the African Institutes for Mathematical Sciences centers (AIMS), of which there are currently six. In the future, there should be 15. The AIMS is a network of the individual centers that supports talented students and teachers of mathematics. Each year, there are over 1,500 applications Africa-wide. The top 300 get their turn and earn a master's degree by means of a one-year scholarship. In October 2017, there was a workshop sponsored by the Volkswagen Foundation at the AIMS Center in Cameroon on "Computer Algebra and Applications" with 120 participants. Another workshop is planned for 2018 with the topic "Orthogonal polynomials and their applications", again organized by myself and my Cameroonian colleague.

Moreover, it is very important to me that visiting scientists can establish contacts and get to know the culture of the host country. As treasurer of the German Association of Humboldtians, I can play a part in this, as our club organises networking meetings for guests throughout Germany. I am also chairman of the board of trustees of the International House at the University of Kassel, which offers a broad cultural program for our international guests."