基于NSGA-Ⅱ的IPMC机器鱼动态多目标相容优化控制

实际控制问题中往往有多个控制目标需要兼顾,且多个目标通常情况下是冲突的。根据相邻控制步之间系统状态和控制输入的连续性,提出了一个基于NSGA-II的动态迭代多目标相容优化控制算法,并且这一算法有能力处理目标空间为非凸的控制问题和提高在线优化速度。考虑到IPMC驱动机器鱼在运行过程中能耗和速度两个关键且冲突的目标,建立IMPC驱动机器鱼的运动及能耗模型,将所提算法进行了应用。仿真结果表明了控制算法的有效性及其在慢复杂系统动态控制中的应用潜力。     

Transient expression of a surface antigen on a small subset of neurones during embryonic development

During development, neurones find and interconnect with their targets in a remarkably precise way. The unfolding of neuronal specificity involves a series of highly specific recognition events which are likely to be coordinated by the spatial and temporal expression of many different surface molecules. At early stages of development, neuronal recognition occurs most dramatically at the tips of growing axons, at growth cones and their filopodia. Previous studies on the grasshopper embryo suggest that specific filopodial contacts lead to the stereotyped patterns of selective axonal fasciculation; these results support the 'labelled pathways' hypothesis which predicts that the different neighbouring axon fascicles in the embryonic neuropil within filopodial grasp are differentially labelled. To uncover the molecular labels on fasciculating embryonic axons, we screened 2,000 monoclonal antibodies generated against the embryonic neuroepithelium. Here we describe three antibodies which reveal surface antigens whose temporal and spatial expression during embryogenesis correlate with the predictions of the model. In particular, the Mes-2 antibody recognizes an antigen which is transiently expressed on the surface of only 4 out of approximately 1,000 neurones in each metathoracic hemisegment during a short period of embryogenesis. The growth cones of two of these neurones fasciculate in the periphery and innervate the same target. Moreover, they transiently express the Mes-2 surface antigen while doing so.     

The diploid genome sequence of an Asian individual

Here we present the first diploid genome sequence of an Asian individual. The genome was sequenced to 36-fold average coverage using massively parallel sequencing technology. We aligned the short reads onto the NCBI human reference genome to 99.97% coverage, and guided by the reference genome, we used uniquely mapped reads to assemble a high-quality consensus sequence for 92% of the Asian individual's genome. We identified approximately 3 million single-nucleotide polymorphisms (SNPs) inside this region, of which 13.6% were not in the dbSNP database. Genotyping analysis showed that SNP identification had high accuracy and consistency, indicating the high sequence quality of this assembly. We also carried out heterozygote phasing and haplotype prediction against HapMap CHB and JPT haplotypes (Chinese and Japanese, respectively), sequence comparison with the two available individual genomes (J. D. Watson and J. C. Venter), and structural variation identification. These variations were considered for their potential biological impact. Our sequence data and analyses demonstrate the potential usefulness of next-generation sequencing technologies for personal genomics.