  We measure the spectrum of low-lying nucleon resonances using Bayesian
fitting methods. We compare the masses obtained in the quenched approximation
to those obtained with two flavours of dynamical fermions at a matched lattice
spacing. At the pion masses employed in our simulations, we find that the mass
of the first positive-parity nucleon excitation is always greater than that of
the parity partner of the nucleon.
