We compute loop corrections to the effective action of a field theory on a
five-dimensional S1/Z2 orbifold. We find that the quantum loop effects of
interactions in the bulk produce infinite contributions that require
renormalization by four-dimensional couplings on the orbifold fixed planes.
Thus bulk couplings give rise to renormalization group running of brane
couplings.Comment: 10 pages, Latex with pictex figure