  We present new parameterizations of vector and axial nucleon form factors. We
maintain an excellent descriptions of the form factors at low momentum
transfers, where the spatial structure of the nucleon is important, and use the
Nachtman scaling variable xi to relate elastic and inelastic form factors and
impose quark-hadron duality constraints at high momentum transfers where the
quark structure dominates. We use the new vector form factors to re-extract
updated values of the axial form factor from neutrino experiments on deuterium.
  We obtain an updated world average value from neutrino-d and pion
electroproduction experiments of M_A = 1.014 +- 0.014 GeV/c2. Our
parameterizations are useful in modeling neutrino interactions at low energies
(e.g. for neutrino oscillations experiments). The predictions for high momentum
transfers can be tested in the next generation electron and neutrino scattering
experiments.
