Negative Imaginary System: A dynamical system whose transfer function displays a negative imaginary part over certain frequency ranges, ensuring stability in positive-feedback interconnections.

Negative feedback is a universal control mechanism that lets a system's output throttle its input. If an engine revs up, negative feedback tapers its power source. But if the engine slows down, it ...

Thus, cells can control downstream sensitivity through the attenuation of signal transfer efficiency by changing the expression level of negative regulators.