  A strong mutual influence of superconductors (S) and ferromagnetic (F)
conductors in hybrid F/S (Ni/Al) nanostructures is observed. The magnitude of a
proximity-induced conductance on the F-side is more than two orders larger than
that predicted by theory. Re-entrance of the superconductors to the normal
state reciprocated by changes on the F-side has been found in low applied
magnetic fields with new peaks in the differential resistance as an effect of
the saturation magnetisation. An analysis has been developed providing a base
for a numerical description of the system. PACS numbers: 74.50.+r, 74.80.Fp,
85.30St
