1.   Additionally, after two years all airports would be required to purchase and use explosives detection screening machines on all checked bags.

2.   Now, such detection is being used in some centers to enhance the effectiveness of film mammography, though it is not yet being used with digital mammography.

3.   Sonar detection is used in special situations, most commomly on an intersection under construction.

4.   Some cities are now using video detection, Loggins added.

5.   Unlike modern fishing and lobstering, which uses sonar detection, the clammer has only his hands and his sixth sense to sleuth out the clams.