Vanormelingen, P. [P:(DE-HGF)0] ; Hegewald, E. [P:(DE-Juel1)VDB575] ; Braband, A. [P:(DE-HGF)0] ; Kitschke, M. [P:(DE-HGF)0] ; Friedl, Th. [P:(DE-HGF)0] ; Sabbe, K. [P:(DE-HGF)0] ; Vyverman, W. [P:(DE-HGF)0]