Figure 2
From: Post-translational regulation enables robust p53 regulation
Feedback analysis. (A) Block diagram representation of the feedback in Eqs. 1–3. X(s), Y(s) and Z(s) are the Laplace transforms of x(t), y(t), and z(t). G Y (s) and G Z (s) are the transfer functions. E(s) is the Laplace transform of the error e(t) between the input and output. D(s) represents the disturbance. (B) Time responses (unit step response) for a second-order system with different damping ratios (p z = p y = 0.01 min-1). (C) As the damping ratio (ζ) increases from 0 to near 1 the %OS decreases from 100% to near 0%. (D) Block diagram representation of the discrete-time feedback model. X(z), Y(z), and Z(z) are the z-transforms of x(i), y(i), and z(i). G Y (z) and G Z (z) are the transfer functions. E(z) is the transform of the error e(i) between the input and output. D(z) represents the disturbance.
