Explicit Internal Signal Stochastic Resonance Research Articles

Influences of a periodic signal on a noisy synthetic gene network

The effects of noise and a periodic signal on a synthetic gene network have been investigated. By tuning the distance of a parameter from the Hopf bifurcation point, both implicit internal signal stochastic resonance and explicit internal signal stochastic resonance can be induced by noise. Furthermore, a switch process can also be elicited. When a periodic signal is coupled to the gene network, two interesting phenomena occur with the modulation of the frequency of the signal: the effect of noise amplifying cellular signal can be inhibited or even destroyed, and “locked” coherence resonance occurs.

Signal transduction in a coupled hormone system: Selective explicit internal signal stochastic resonance and its control

Cooperative interactions of signal transduction and environmental noise are investigated with a coupled hormone system, in which selective explicit internal signal stochastic resonance (EISSR) is observed. More specifically, the large peak of a period-2 oscillation (i.e., a strong signal) is greatly amplified by the environmental noise while the small peak (i.e., a weak signal) does not exhibit cooperative interactions with noise. The EISSR phenomenon could be controlled by adjusting the frequency or amplitude of an external signal and a critical amplitude for external signal is found. Significantly, the maximal signal-to-noise ratio increases almost linearly with the increment of control parameter, despite that the magnitude of the large peak is decreased. In addition, the noise does not alter the fundamental frequencies of the strong signal and the weak signal, which implicates that the system can keep its intrinsic oscillatory state and resist the effect of environmental fluctuations.

Implicit and explicit internal signal stochastic resonance in calcium ion oscillations

Responses of Ca 2+ oscillations to random perturbation are investigated at the conditions where the system stays at a steady state (before bifurcation point) or an oscillatory state (after bifurcation point). It is found that noise can induce both implicit and explicit internal signal stochastic resonance (IISSR and EISSR). In particular, the internal signal stochastic bi-resonance is also observed. When an external signal is added to the system, no IISSR or EISSR phenomenon occurs, implying an external signal destroys cooperation of Ca 2+ signal and environment noise.

The influence of coupling on internal stochastic resonance in neural system

A noisy biological system is applied to investigate the influence of coupling on the internal stochastic resonance. It is found that the internal stochastic resonance could be transferred by coupling, and the enhancement and suppression of the stochastic resonance could be realized by controlling the coupling strength at proper range. The explicit internal signal stochastic resonance without tuning occurs. An appropriate coupling strength is found to enhance the propagation of the internal stochastic resonance most effectively with the increment of the external noise.

Explicit internal signal stochastic resonance and mechanic of noise-resistance in a chemical oscillator

The explicit internal signal stochastic resonance (EISSR) that happened in the Willamowski–Rössler reaction model was investigated. The z-variable's output signal-to-noise ratio (SNR) as a function of the noise intensity shows non-monotonic behavior, indicating the occurrence of EISSR. It is first found that EISSR happened in the periodic-2 oscillations state. A worthy noting point is that the fundamental frequency of the intrinsic period signal of the system is shifted little with the change of noise intensity. EISSR is a cooperative effect of the intrinsic period signal and external noise or fluctuations. Our studies have shown that EISSR can lead to noise-resistance of the chemical oscillator.

Explicit internal signal stochastic resonance in a chemical oscillator

Explicit internal signal stochastic resonance (EISSR) is first found in the periodic-2 oscillations state of Willamowski-Rossler reaction model.

Noise enhanced the preponderant oscillation

Explicit internal signal stochastic resonance (EISSR) is investigated in the Willamowski-Rossler reaction model located in the dynamical region of periodic-2 oscillations, which subjects to Gaussian white noise. The z-variable's output signal-to-noise ratio (SNR) as a function of the noise intensity shows non-monotonic behavior, indicating the occurrence of EISSR. It is first found that EISSR happened in the periodic-2 oscillations state. When the system exist two intrinsic signals, noise can enhance the preponderant oscillation signal.

Controlling of explicit internal signal stochastic resonance by external signal.

Explicit internal signal stochastic resonance (EISSR) is investigated in a model of energy transduction of molecular machinery when noise is added to the region of oscillation in the presence of external signal (ES). It is found that EISSR could be controlled, i.e., enhanced or suppressed by adjusting frequency (omega(e)) and amplitude (A) of ES, and that there exits an optimal frequency for ES, which makes EISSR strength reach the maximum. Meanwhile, a critical amplitude (A(c)) is found, which is a threshold of occurrence of EISSR. Finally, the difference and similarity between EISSR and IISSR (implicit internal signal stochastic resonance) are discussed.

Simulation of explicit internal signal stochastic resonance in a qualitative model for intercellular calcium ion oscillations

Explicit internal signal stochastic resonance (EISSR) is investigated numerically when noise is added to the region of periodic-2 oscillatory state in intercellular calcium ion oscillations. It is found that the signal-to-noise ratio (SNR) of strong signal (SS) has a maximum value at an optimal noise intensity and that of weak signal (WS) increases monotonously with the increment of noise intensity. These results indicate that the EISSR has selectivity to two intrinsic signals of system. Moreover, the frequencies of SS and WS hardly change, which implies that system can resist to the effect of noise and sustain intrinsic period oscillatory states.

Internal signal stochastic resonance induced by colored noise in an intracellular calcium oscillations model

An intracellular calcium oscillations model subject to external colored noise is investigated. Internal signal stochastic resonance (ISSR) can be induced and significantly influenced by colored noise. The signal-to-noise ratio (SNR) exhibits two maxima with the increment of the correlation time as the noise intensity is fixed, indicating the occurrence of stochastic bi-resonance. Additionally, we find ISSR and explicit internal signal stochastic resonance (EISSR) have quite similar responses to colored noise, which implies there are some commonalities in their mechanisms.

Selectivity of explicit internal signal stochastic resonance in a chemical model

The explicit internal signal stochastic resonance (EISSR) that happened in the Willamowski–Rössler model was studied. EISSR is a cooperative effect of the intrinsic signal and external noise or internal fluctuation. Our studies have shown that EISSR can exist in the stable periodic-2 oscillation state. The output signal to noise ratio (SNR) of the strong signal (SS) versus noise intensity exhibits explicitly nonmonotonic character. The output SNR of the weak signal decreases with the increment of noise intensity. It is clear that EISSR can hold selectivity to the preponderant intrinsic signal when there are two intrinsic signals in the system. At the same time, the fundamental frequency of the SS almost does not alter. These properties imply that the system can resist to the effect of noise and sustain preponderant intrinsic oscillation by itself. Our results will be helpful to better understand circadian rhythm and signal detecting in creatures.

Noise-enhanced energy transduction of molecular machinery

We have numerically investigated the enhance effect of noise on the energy transduction of molecular machinery. The energy transduction is enhanced with the increase of relative amplitude of the limit-cycle oscillation in polymer chain. And noise can enlarge the relative amplitude through a mechanism of stochastic resonance (SR). In the simulation, two different types of SR, internal signal SR (ISSR) and explicit ISSR (EISSR) are studied, respectively. And the similarity as well as difference between them was presented. The potential application of the enhance effect of energy transduction is then discussed.

Explicit internal signal stochastic resonance in a chemical model driven by colored noise

A modified Oregonator model subject to colored noise is investigated. As the model system locates in the dynamical region of period-1 oscillation, the flow rate is modulated by exponential Gaussian colored noise. The signal-to-noise ratio (SNR) as a function of the noise intensity shows the nonmonotonic behavior, indicating occurrence of explicit internal signal stochastic resonance (EISSR). The colored noise can weaken EISSR, and the maximum effect of EISSR is shifted to lower noise intensity with the increment of the correlation time. The SNR also shows resonance behavior with the variation of the correlation time as the noise intensity is fixed.

Explicit internal signal stochastic resonance in a chemical model

A Belousov–Zhabotinsky (BZ) reaction model subject to additive Gaussian white noise is investigated as the model system is located in the dynamical region of period-1 oscillation. The model is composed of three ordinary differential equations representing the time evolutions of HBrO2 , Ce(IV), and BrCH(COOH)2 , respectively. Noise is separately added to the three equations. In all three cases the change in the Ce(IV) variable's output signal-to-noise ratio (SNR) as a function of the noise intensity shows non-monotonic behavior, indicating the occurrence of explicit internal signal stochastic resonance. However, its strength is quite different in each case, implying that the three reacting species play different roles in determining the dynamical behavior in the BZ reaction. The change in the peak height of the Ce(IV) variable's output frequency spectrum and the shift of the peak's central frequency with increasing noise intensity are also examined.