Effects of nonperturbatively improved dynamical fermions in QCD at fixed lattice spacing by Allton, C, Booth, S, Bowler, K, Garden, J, Hart, A, Hepburn, D, Irving, A, Joo, B, Kenway, R, Maynard, C, McNeile, C, Michael, C, Pickles, S, Sexton, J, Sharkey, K, Sroczynski, Z, Talevi, M, Teper, M, Wittig, H, Collaboration, UKQCD