1.The 25^th annual conference of the British Phycological Society, Royal Holloway College, University of London, Jan. 1977 (attendance).

2.The 3^rd International Conference on Photosynthetic Prokaryotes, Oxford University, Jan. 1979 (Joint contribution by Pearson, Howsley and Mahdi ).

3.First Coordination Meeting, Nile Valley Project of the International Center for Agricultural Research in the Dry Areas (ICARDA), Khartoum, Sept. 1981 (Joint contribution by Habish, Mahdi and Khairi).

4.The 2^nd Coordination Meeting, ICARDA/IFAD Nile Valley Project, Khartoum, Sept. 1982 (Joint contribution by Habish and Mahdi).

5.The 3^rd Coordination Meeting, ICARDA/IFAD Nile Valley Project, Sakha, Egypt, Sept. 1983 (Joint contribution by Mahdi, Mohamed and Mukhtar).

6.The 2^nd Conference of the African Association for Biological Nitrogen Fixation (AABNF), Cairo, Egypt, Dec. 1986 (Participation in discussion).

7.Symposium of the British Institute of Biology, North Ireland branch, on “New Developments in the Production and Processing of Food”, Belfast, April 1989 (Participation in discussion).

8.The 8^th Conference of the African Association for Biological Nitrogen Fixation, Pretoria, South Africa, 23-27 Nov.1998 (Joint contribution by El Amin, Mahdi and Mekki).

9.The Workshop on “Writing and Editing for Distance Education”, Khartoum, April 1999 (Training and award of certificate).

10.The Workshop on “DNA Molecular Marker Techniques for Crop Improvement”, organized by ICARDA and the Commission for Biotechnology and Genetic Engineering, Khartoum, Feb.2001 (Training and award of certificate).