  Recent measurements of the neutron's electric to magnetic form factors ratio,
R_n= \mu_n G_E^n/G_M^n, up to 3.4 (GeV/c)^2 combined with existing R_p= \mu_p
G_E^p/G_M^p measurements in the same Q^2 range allowed, for the first time, a
separation of the up- and down-quark contributions to the form factors at high
Q^2, as presented by Cates, et al. Our analysis expands on the original work by
including additional form factor data, applying two-photon exchange (TPE)
corrections, and accounting for the uncertainties associated with all of the
form factor measurements
