Before revision:  Although the origin of multiple feedback loops is often accounted for by the notion of passive robustness against perturbation, we here studied active benefits of the period mismatch on the efficiency of  genetic oscillators.
After revision:  Although the origin of multiple feedback loops is often accounted for by the notion of passive robustness against perturbation, we here studied active benefits of the period mismatch , which include increasing the efficiency of genetic oscillators.