  The precise knowledge of parton distribution functions (PDFs) is
indispensable to the accurate calculation of hadron-initiated QCD hard
scattering observables. Much of our information on PDFs is extracted by
comparing deep inelastic scattering (DIS) and lepton pair production (LPP) data
to convolutions of the PDFs with the partonic cross sections of these
processes. It is known that partonic cross sections receive large corrections
in regions of phase space near partonic thresholds that can be resummed using
threshold resummation techniques. The effect of threshold resummation on DIS
and LPP differs because partonic thresholds for the two processes occur in
different kinematic regions. Recent global fits for PDFs have included DIS data
from the large Bjorken x and moderate Q^2 region where threshold effects have
been shown to be large. The present project explores the effects of
simultaneously incorporating threshold resummation in both DIS and LPP and to
evaluate the effects of such additions on global fits.
