Positive Feedback in Cardioprotection

Positive feedback in cardioprotection: can more mechanism lead to translation?

Positive feedback

Positive feedback is a process that occurs in a feedback loop in which the effects of a small disturbance on a system include an increase in the magnitude of the perturbation.[1] That is, A produces more of B which in turn produces more of A.[2] In contrast, a system in which the results of a change act to reduce or counteract it has negative feedback.[1][3] Mathematically, positive feedback is...

Feedback and positive feedback stabilizability and holdability

Consider the following problem. Given a discrete-time linear system, find, if possible, linear state-feedback control laws such that under these laws all trajectories originating in the non-negative orthant of the state space remain non-negative while asymptotically deteriorating to the origin. This problem is called feedback stabilizability-holdability problem (FSH). If, in addition, the requi...

Physiological Positive Feedback Mechanisms

In positive feedback mechanisms, the response to a stimulus does not stop or reverse it but instead keeps the sequence of events going up. At first glance, this would appear to be a counter to the principle of homeostasis, since a positive feedback loop has no obvious means of stopping. Not surprisingly, therefore, the positive feedback is less common in nature than the negative one. A positive...

Positive Feedback Promotes Oscillations in Negative Feedback Loops

A simple three-component negative feedback loop is a recurring motif in biochemical oscillators. This motif oscillates as it has the three necessary ingredients for oscillations: a three-step delay, negative feedback, and nonlinearity in the loop. However, to oscillate, this motif under the common Goodwin formulation requires a high degree of cooperativity (a measure of nonlinearity) in the fee...