  We summarize the current status of our numerical results for the gluon and
ghost propagators and for the Kugo-Ojima confinement parameter in quenched
SU(3) lattice Landau gauge theory. The data for the propagators are compared to
our results obtained in the case of full QCD, simulated using two flavors of
dynamical clover-improved Wilson fermions. We demonstrate that the infrared
behavior of the ghost propagator is consistent with the Kugo-Ojima confinement
criterion. Explicit violation of reflection positivity by the gluon propagator
is shown. Additionally, we present results of a running coupling constant both
at low and at large momenta.
