  A non-perturbative approach to Generalized Parton Distributions, and to
Deeply Virtual Compton Scattering in particular, based on off mass shell
extension of dual amplitudes with Mandelstam analyticity (DAMA) is developed
with the spin and helicity structure as well as the threshold behavior
accounted for. The model is tested against the data on deep inelastic
electron-proton scattering from JLab.
