  The small, about 30% magnetoresistance at the onset of full spin polarization
in the 2D electron system in a modulation-doped Si/SiGe quantum well gives
evidence that it is the remote doping that determines the transport scattering
time. Measurements of the mobility in this strongly-interacting electron system
with remote-doping scattering allow us to arrive at a conclusion that the
Hubbard form underestimates the local field corrections by about a factor of 2.
