  We examine active-sterile neutrino conversion in the late time
post-core-bounce supernova environment. By including the effect of feedback on
the Mikheyev-Smirnov-Wolfenstein (MSW) conversion potential, we obtain a large
range of neutrino mixing parameters which produce a favorable environment for
the r-process. We look at the signature of this effect in the current
generation of neutrino detectors now coming on line. We also investigate the
impact of the neutrino-neutrino forward scattering-induced potential on the MSW
conversion.
