The stronger your signal (the more bars you have) the more likely it is that you're close to a cell tower. However, this is an unreliable way to decipher your signal strength.

The molecular understanding of the guard cell signal transduction network opens possibilities for engineering stomatal responses to control CO2 intake and plant water loss.

Searching Amazon for cellular signal boosters feels like navigating a minefield. Prices range anywhere from $180 to $1,000 and up, and reviews tend to be all over the place for every device offered.