The police are now monitoring criminal/gang/drug 'activity' in the area.
There has been an increase in the city's (level of) economic 'activity'.
The instruments are used to detect volcanic 'activity' on the island.
(..) - Got it. Memphis General, medical unit . We're inbound with a male police officer with severe facial lacerations. Weapon unknown. We've got grand mal seizure activity but he's post-ictal now. Vital signs are good. Pressure is over . - ? - Yeah, that's right, . Pulse . (..)1991 The Silence of the Lambs