论文标题
快速灭活对有条件的第一次通行时间的影响
The effects of fast inactivation on conditional first passage times of mortal diffusive searchers
论文作者
论文摘要
搜索者第一次发现目标时称为第一个通道时间（FPT）。在许多物理，化学和生物过程中，搜索者是“致命的”，这意味着在找到目标之前，搜索者可能会失活（降解，死亡等）。在细胞内信号传导的背景下，如果搜索者有条件是在失活之前找到目标，那么快速失活的一项重要工作发现，快速失活会大大改变致命扩散搜索者的条件FPT分布。在本文中，我们证明了一个一般定理，该定理在快速失活极限内为此类fpts的所有矩提供一个明确的公式。该公式非常普遍，因为它在扩散搜索器动力学，目标和空间域的非常普遍的条件下。这些结果证明，如果灭活速度很快，那么与失活的FPT相比，有条件的FPT要快得多，（ii）受空间异质性影响的影响要小得多，并且（iii）可变差得多。我们的结果与特定离散细胞内扩散模型的最新计算和理论分析一致，并确认与空间异质性对细胞内信号传导的影响有关的猜想。
The first time a searcher finds a target is called a first passage time (FPT). In many physical, chemical, and biological processes, the searcher is "mortal," which means that the searcher might become inactivated (degrade, die, etc.) before finding the target. In the context of intracellular signaling, an important recent work discovered that fast inactivation can drastically alter the conditional FPT distribution of a mortal diffusive searcher, if the searcher is conditioned to find the target before inactivation. In this paper, we prove a general theorem which yields an explicit formula for all the moments of such conditional FPTs in the fast inactivation limit. This formula is quite universal, as it holds under very general conditions on the diffusive searcher dynamics, the target, and the spatial domain. These results prove in significant generality that if inactivation is fast, then the conditional FPT compared to the FPT without inactivation is (i) much faster, (ii) much less affected by spatial heterogeneity, and (iii) much less variable. Our results agree with recent computational and theoretical analysis of a certain discrete intracellular diffusion model and confirm a conjecture related to the effect of spatial heterogeneity on intracellular signaling.
