IMAGE RECONSTRUCTION OF ICOSAHEDRAL PARTICLES

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 虽然EMAN已经成功地用于病毒颗粒的二十面体和不对称重构，但是颗粒取向细化的EMAN方法对于大病毒颗粒是非常CPU密集型的过程。消耗了一百万个CPU小时来确定ε 15噬菌体的4.5 μ图（Jiang等人，2008年）使用NSF支持的TeraGrid计算设施。使用NCMI可用的簇结合外部超级计算机分配的类似结构确定花费了12个多月的时间，从约23，000个粒子图像中细化P22噬菌体的单一结构。因此，我们为这样的大型物体寻找替代方法，具有相同的精度，但更高的CPU效率。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Though EMAN has been used successfully for icosahedral and asymmetric reconstruction of virus particles, the EMAN method of particle orientation refinement is a very CPU intensive process for large virus particles. One million CPU hours were consumed to determine the 4.5 ¿ map of the epsilon15 phage (Jiang et al., 2008) using the NSF supported TeraGrid computing facility . A similar structure determination using the clusters available at the NCMI combined with outside supercomputer allocations has taken over 12 months to refine a single structure of P22 phage from ~23,000 particle images. We, therefore, look for alternative methods for such large objects, with the same accuracy but a higher CPU efficiency.