A message to the G8 summit by Aldhous, P, Butler, D, Giles, J, Hopkin, M, Peplow, M, Schiermeier, Q, Mugabe, J, Marsh, K, Binka, F, Murenzi, R, Henning, M, Mocumbi, P, Nyong, A, Jensen, M, Wambugu, F, Davidson, O