If parasites can be considered as promising sentinels, we need reasons for the establishment of ' new ' indicators.
Of 185 sentinels recovered, 2n7 % had single-species infections.
Using the adjoint problem, one shows that the existence of these sentinels is reduced to the solution of exact controllability problem with constraints on the state.
They are certainly sentinels of the environment in which we live because dogs generally share that environment, sometimes very closely indeed.
They stand as sentinels scrutinising concentrations of public and private power.
They seem to me to deserve the highest praise of all as the silent sentinels who make an audience possible.
No clinical signs or seroconversion were observed in the uninoculated sentinel rabbit kept in the same room as the inoculated rabbits.
One of the tower's sentinels died in the lightning strike.