In particular, the current flow at any point 15 can vary in {HEAD ~ proportion} to {TAIL ~ the stress} at that point 
to
In particular , the current flow at any point 15 can vary in { HEAD ~ proportion } to { TAIL ~ the stress } at that point
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH