共查询到14条相似文献,搜索用时 89 毫秒
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By constructing a mesoscopic stochastic model for intracellular calcium oscillations in coupled cell system, we investigated the influence of internal noise on the detection of weak stimulation using the chemical Langevin equation (CLE). We found that an optimal cell size V existed for a coupled cell chain length N and an optimal value of N existed for a given cell size V. At these values, the collective calcium oscillations showed the best performance, indicating the occurrence of“system size resonance (SSR)”or“internal noise stochastic resonance (INSR)”. And such a phenomenon was robust to the coupling strength. Living cells may have learned to exploit the internal noise to detect weak stimulation via the mechanism of INSR, and then encode information to specifically regulate distinct cellular functions. It is interesting to note that the optimal cell size is always present at V抑103 μm3, which is close to the real living cell size in vivo. Since the internal noise in living systems can not be ignored and the systems may often encounter weak stimulations, our findings might have significance for stimulation detecting processes in living systems. 相似文献
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基于周期调节的随机共振算法对化学弱信号的检测研究 总被引:3,自引:0,他引:3
提出了一种新的随机共振算法,通过对系统的周期进行调节以实现系统的共振.讨论了实现共振的系统参数,并对模拟信号和拉曼光谱实验信号进行了处理.结果表明,该方法不仅可方便地用于弱化学信号的处理,克服检出信号的滞后现象,而且对不同噪声水平的信号均有良好的适用性. 相似文献
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一种有效提取弱信号的新方法 总被引:13,自引:0,他引:13
随机共振 ( Stochastic Resonance,简称 SR)最初由 Benzi[1] 于 1 981年提出 ,并在气象学领域中得到了成功的应用 .根据随机共振理论 ,通过加噪声可在某一“共振”点处大幅度提高信号的信噪比 .这种方法也已成功地应用于方波脉冲信号的恢复 [2 ] ,但在化学信号中的应用尚属空白 .我们首次将这种方法用于化学弱信号的检测 ,并在简单喇曼谱图的解析中获得成功 [3 ] .但是 ,加噪声的方法作为一种有效的信号分析手段还显得很不成熟 .具体表现为处理过程较繁 ,分析信号的峰位偏移明显 ,而且结果在一定程度上要依赖人为判断来决定 [3 ] . 在… 相似文献
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Dynamics of calcium oscillation in a coupled cell system is discussed. It shows that when one end of the cell chain is perturbed by noise, the signal induced by noise can propagate along a linearly coupled cell chain with considerable enhancement, a rather ordered internal signal can be obtained on the other end, and the signal itself can also be enhanced. The effects of coupling constant, noise intensity and coupling means on the propagation of the signal are investigated. It is found that there exist an optimal coupling constant and noise intensity in favor of the signal propagation. What′s more, a qualitative explanation via the signal and the noise background is given. And the one way coupling is better for the signal propagation and enhancement than for the two way coupling. The results may have important applications in living cell systems, where information is transmitted along a cell chain. 相似文献
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用化学Langevin方程研究了内噪声对介观振荡化学反应体系的影响.研究发现,在确定性体系处于定态条件下,内噪声可以导致体系振荡:随着内噪声强度的变化,诱导振荡信号的信噪比通过一个极大值,表明内噪声随机共振的出现;由于内噪声强度随着系统体积的变化而改变,因此,这一现象也证明了系统尺度共振,即最佳尺度效应的存在. 相似文献
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噪声在非线性化学体系中作用的研究现状* 总被引:9,自引:0,他引:9
本文综述了噪声的种类、来源、统计性质、作用机制和在不同体系中噪声诱导的丰富的非线性的动力学行为, 重点叙述了噪声在非线性化学体系中的重要作用及其应用。 相似文献
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Taking into account the existence of internal noise in small scale biochemical reaction systems, we studied how the internal noise would influence the detection of weak external signal in the cell system using chemical Langevin equation. The weak signal was too small to, separately, fire calcium spikes for the cell. We found that, near the Hopf bifurcation point, the internal noise could help the calcium oscillation signal cross a threshold value, and at an optimal internal noise level, a resonance occurred among the internal noise, the internal noise-induced calcium oscillations, and the weak signal, so as to enhance intensively the ability of the cell system to detect the weak signal. Since the internal noise was changed via the cell size, this phenomenon demonstrated the existence of an optimal cell size for the signal detection. Interestingly, it was found that the optimal size matched well with the real cell size, which was robust to external stimulus, this was of significant biological meaning. 相似文献
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The influence of internal noise on the calcium oscillations is studied. It is found that stochastic calcium oscillations occur when the internal noise is considered, while the corresponding deterministic dynamics only yields a steady state. Also, the performance of such oscillations shows two maxima with the variation of the system size, indicating the occurrence of system size resonance. This behavior is found to be intimately connected with the canard phenomenon. Interestingly, it is also found that one of the optimal system sizes matches well with the real cell size, and such a match is robust to the variation of the control parameters. 相似文献