  The Landau gauge Schwinger-Dyson Equation for the quark self-energy is solved
in the quenched ladder approximation for several cases of one- and
two-quark-generations. The exchanges of Standard Model gluons and Higgs bosons
are taken into account. It is found that Higgs boson exchange dominates the
quark self-energy for sufficiently large input quark masses (>75 GeV), causing
the running quark propagator mass to increase with energy-scale. The running of
the quark mixing angles is also considered. No running of the quark mixing
angles is found, to one part in a billion, for input quark masses up to and
including 500 GeV.
