RQ-1A Predator is a long-endurance, medium-altitude unmanned aircraft system for surveillance and reconnaissance missions. Predator UAVs have been operational in Bosnia since 1995, where they have flown more than 600 missions for more than 4,000h in support of Nato, UN and US operations. Predator operated from a tactical control station located aboard the USS Carl Vinson, Nimitz class aircraft carrier.
Secretin functions as a type of fireman: it is released in response to acid in the small intestine, and stimulates the pancreas and bile ducts to release a flood of bicarbonate base, which neutralizes the acid. Secretin is also of some historical interest, as it was the first hormone to be discovered. similar, but quantitatively less important response to secretin is elicited by bile duct cells, resulting in additional bicarbonate being dumped into the small gut. As acid is neutralized by bicarbonate, the intestinal pH rises toward neutrality, and secretion of secretin is turned off.
The pancreas also has other protective mechanisms to ensure that these enzymes do not damage it. The cells of the pancreas secrete trypsin inhibitor which ensures that trypsin is not activated within the pancreas and it turn, neither are the other proteases.Action of Trypsin, Chymotrypsin and Carboxypolypetidase. Trypsin and chymotrypsin breaks down protein into peptides.f these, trypsin is the most abundant. The pancreas do not secrete these enzymes in it active form as this may result in digestion of the pancreas itself. Instead each enzyme is secreted in an inactive form as follows 1  : Trypsin is secreted as trypsinogen.