  We calculate nucleon-nucleon cross sections in the nuclear medium with
unequal densities of protons and neutrons. We use the
Dirac-Brueckner-Hartree-Fock approach together with realistic nucleon-nucleon
potentials. We examine the effect of neutron/proton asymmetry and find that,
although generally mild, it can be significant in specific regions of the phase
space under consideration.
