  I discuss advances in the determination of strange, charm, and bottom quark
parton distribution functions obtained in the CTEQ6.5 and CTEQ6.6 global
analyses. These results affect electroweak precision observables and certain
new physics searches at the Large Hadron Collider. I focus, in particular, on
high-energy implications of the consistent treatment of heavy-quark threshold
effects in DIS in the general-mass factorization scheme; an independent
parametrization for the strangeness PDF; and the possible presence of
nonperturbative ("intrinsic") charm.
