  We previously developed an algorithm, called resolution exchange, which
improves canonical sampling of atomic resolution models by swapping
conformations between high- and low-resolution simulations[1]. Here, we
demonstrate a generally applicable incremental coarsening procedure and apply
the algorithm to a larger peptide, met-enkephalin. In addition, we demonstrate
a combination of resolution and temperature exchange, in which the coarser
simulations are also at elevated temperatures. Both simulations are implemented
in a ``top-down'' mode, to allow efficient allocation of CPU time among the
different replicas.
