Stochastic Simulation Of Excitation-contraction Coupling

48个处理器的专用集群已经投入使用，软件也已安装。 包括所有细胞空间和时间尺度上的扩散和运输过程的3d模型的开发工作正在进行中。 这涉及到完全重新编码蒙特卡罗算法，将其分层嵌入到一系列处理不同尺度的嵌套求解器中。 同时，我们建立了两个近似模型。 其中一个模型在二维网格上程式化了钙释放单元，并且似乎能够解释局部钙释放事件的一系列令人惊讶的行为。 这个模型现在已经在集群上并行化了，允许累积大量事件的统计数据。 第二，非随机模型的开发，这是出乎意料的成功占的稳健性和激素调节的起搏活动的窦房结细胞。

SUMMARY OF WORK The dedicated 48-processor cluster has been commissioned and software installed. Work on development of the 3d model including diffusion and transport processes on all cellular spatial and temporal scales is underway. This involves completely recoding the Monte Carlo algorithm to embed it hierarchically in a nested series of solvers handling different scales. Meanwhile, we have constructed two approximate models. One of these models stylized calcium release units on a two-dimensional grid, and appears able to account for a surprising range of behaviors of local calcium release events. This model has now been parallelized on the cluster, allowing statistics of large numbers of events to be accumulated. A second, non-stochastic model was developed which has been unexpectedly successful in accounting for the robustness and hormonal regulation of the pacemaking activity of sino-atrial node cells.