One can imagine how an external signal could activate a gene like myogenin and so guide the cell down the muscle pathway.

Such signals will read the driver's mind, translate intentions into action, and activate the signal without human help.

At most crossings, the signals will activate about 30 seconds before the train arrives.

In standard television, the signal activates an electron gun that fires electrons at red, green and blue phosphors, which glow to form an image.

Nothing happens until a signal from the alien ship activates the case contents.

That signal, which is coded to the vehicle that was reported stolen, activates the transmitter in the vehicle.

This allows rapid generation of proteins when a signal activates translation.

"Until the deep-space signal activated it," Mick finishes.

When I give the signal, computer, activate shields.

A coded signal activates a 120db siren and the vehicle's indicators flash alternately.