Some features of the solutions to the truncated Dyson-Schwinger
equations(DSEs) for the propagators of QCD in Landau gauge are summarized. In
particular, the Kugo-Ojima confinement criterion is realized, and positivity of
transverse gluons is manifestly violated in these solutions. In Landau gauge,
the gluon-ghost vertex function offers a convenient possibility to define a
nonperturbative running coupling. The infrared fixed point obtained from this
coupling which determines the 2-point interactions of color-octet quark
currents implies the existence of unphysical massless states which are
necessary to escape the cluster decomposition of colored clusters. The gluon
and ghost propagators, and the nonperturbative running coupling, are compared
to recent lattice simulations. A significant deviation of the running coupling
from the infrared behavior extracted in simulations of 3-point functions is
attributed to an inconsistency of asymmetric subtraction schemes due to a
consequence of the Kugo-Ojima criterion: infrared enhanced ghosts.Comment: 4 pages, no figures, talk given by R.A. at ``Quark Nuclear Physics
2000'', Adelaide, Feb. 21 - 25, 200
