Additionally, {HEAD ~ information} from multiple experiments is utilized to improve {TAIL ~ the accuracy} of calling unknown bases 
is utilized to improve
Additionally , { HEAD ~ information } from multiple experiments is utilized to improve { TAIL ~ the accuracy } of calling unknown bases
OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH