  We present a high resolution, SparsePak two-dimensional velocity field for
the center of the low surface brightness (LSB) galaxy DDO 39. These data are a
significant improvement on previous HI or Halpha long slit data, yet the inner
rotation curve is still uncertain due to significant noncircular and random
motions. These intrinsic uncertainties, probably present in other LSB galaxies
too, result in a wide range of inner slopes being consistent with the data,
including those expected in cold dark matter (CDM) simulations. The halo
concentration parameter provides a more useful test of cosmological models than
the inner slope as it is more tightly constrained by observations. DDO 39's
concentration parameter is consistent with, but on the low end of the
distribution predicted by CDM.
