Periodically, {HEAD ~ the Centralized Secure Database} 101 is synched with Administrator Database 104 and {TAIL ~ each Investigator Database} 106 
is synched with
Periodically , { HEAD ~ the Centralized Secure Database } 101 is synched with Administrator Database 104 and { TAIL ~ each Investigator Database } 106
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH