General discussion by Hancock, G, Hackett, P, Rayner, D, Humphries, M, Dietrich, P, Quack, M, Seyfang, G, Lupo, D, Levy, MR, Brickman, R, Cox, D, Kaldor, A, Sutcliffe, E, Hutson, J, King, D, Houston, P, Freed, K, McCoustra, MRS, Pfab, J, Castleman, A, Sarre, P, Zare, R, Simons, J, Gorry, P, Rosmus, P