The chemical evolution of the Galaxy: the importance of stars with an   initial mass larger than 40Mo
  In the present paper we investigate in how far stars with an initial mass larger than 40Mo affect the chemical enrichment of the Galaxy. We illustrate the importance for chemical yields of a most up to date treatment of the various stellar wind mass loss episodes in stellar evolutionary codes and we discuss the effects of a possible supernova-like outburst prior to massive black hole formation. 
E. De Donder and D. Vanbeveren