The decisions modifying the structure of the Working Group, including arrival of departure of new member teams, change of objectives, will have to be taken by the Board that is composed of the coordinator and of the principal investigator of each participating site. The Board need not have a physical meeting to take decisions; all communication means can be used, provided all members receive the same information. Decisions are taken through a simple majority vote (with the coordinator vote taking precedence in case of a tie.) After the first General Meeting a number of Specialist Groups will be created. Specialist Groups are created or ended by the Board.