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