选择与适应:兰科植物查尔酮合酶基因家族成员的分子进化和功能趋异

回顾了近十五年来国内外对各科植物查尔酮合酶基因CHS分子进化的研究成果,并结合作者近年来对兰科植物CHS基因分子进化的研究结果,对兰科植物CHS基因分子进化和功能趋异的机制展开综述,揭示了植物中普遍存在的CHS基因分子进化以及伴随的功能趋异的现象和机制,初步探讨了CHS基因分子进化与生物进化和自然选择的关系。     

New evidence of homoplasy within the African genus Varicorhinus (Cyprinidae): an independent origin of specialized scraping forms in the adjacent drainage systems of Ethiopia inferred from mtDNA analysis

Interrelationships of the two specialized scraping periphyton-feeders, Varicorhinus beso and V. jubae, and some large African barbs, Labeobarbus spp., inhabiting three main regions of Ethiopia (the Western and Eastern Plateaus, and the Rift Valley separating them) were investigated using the sequence analysis of a fragment (609 base pairs) of the mtDNA control region. The two scraping forms in question appeared to be phylogenetically distant: V. beso had branched off before the main radiation of the Ethiopian Labeobarbus took place, whereas V. jubae is a sister group of the Labeobarbus gananensis complex sympatrically occurring with it in the south of the Eastern Plateau. For geographical reasons, among the congeneric species, V. jubae could be considered as the most closely related to V. beso, the type species of the genus, but judging from the available data this genus seems to be monotypic, while jubae should be classified as a member of Labeobarbus.     

Differential evolution algorithm for solving multi-objective crop planning model

This study presents four strategies of a novel evolutionary algorithm, multi-objective differential evolution algorithm (MDEA). The four strategies namely, MDEA1, MDEA2, MDEA3 and MDEA4 are adapted to solve the multi-objective crop planning model with multiple constraints in a farmland in the Vaalharts irrigation scheme (VIS) in South Africa. The three objectives of the model are to minimize the total irrigation water (m²) and to maximize both the total net income in South African Rand (ZAR) from farming and the total agricultural output in tons. The total area of the farm is 771,000 m² and supplied with 704,694 m² of irrigation water annually. Numerical results produce non-dominated solutions which converge to Pareto optimal fronts. MDEA1 and MDEA2 strategies with binomial crossover method are better for solving the crop planning problem presented than MDEA3 and MDEA4 strategies with exponential crossover method. MDEA1 found a solution with the highest total net income of ZAR 1,304,600 with the corresponding total agricultural output, total irrigation water and total planting areas of 316.26 tons, 702,000 m³ and 725,000 m², respectively. The planting areas for the crops in the solution are 73,463 m² for maize, 551,660 m² for groundnut, 50,000 m² for Lucerne and 50,000 m² for Peacan nut. It can be concluded that MDEA is a good algorithm for solving crop planning problem especially in water deficient areas like South Africa.     

鄂尔多斯市工业化进程中产业结构的演进分析

鄂尔多斯市是我国重要的能源重化工基地,因其工业经济呈现出超常规的发展态势,被称为鄂尔多斯现象。文中以鄂尔多斯市的工业经济和三次产业为研究对象,利用1949～2009年间的产值与就业结构统计数据,对其工业化进程与产业结构的变动轨迹进行了分析。结果表明:60a来,鄂尔多斯市工业化发展阶段性特征明显,目前其工业经济已进入重工业化的中后期阶段。三次产业中,第一产业的产值与就业比重快速下降,二、三产业比重持续上升,并行发展;就业结构虽逐年优化,但仍相对滞后于产业结构与工业化进程,产业结构与就业结构的协调度较低。近年来工业结构的重化趋势凸显,工业主导型的产业结构与主导产业群已经形成。     

植物基因组上游开放阅读框的挖掘方法及其翻译调控

基因组中约有20％的基因具有上游开放阅读框（upstream open reading frame，uORF），它位于成熟mRNA 5''端非编码区（5''-UTR）。本文简介了uORF同源群的挖掘方法、分类和进化，以及调控下游mORF翻译的研究进展。植物（拟南芥和水稻等）和昆虫（果蝇等）基因组中普遍存在保守肽uORFs，并且在序列多样性方面有相似之处。但它们在平均长度、基因组聚类、与甲基转移酶的关联性上有所不同。植物uORF的长度通常短于昆虫uORF。借助拟南芥和水稻全长cDNA序列比较，不同的uORF同源群对其下游如转录因子，信号转导因子、发育信号分子和翻译起始因子eIF5等编码基因的mORF具有调控功能。对于真核生物基因组中包含CHCH域的uORF进行贝叶斯系统发育分析，结果表明，同源群8-like分属5个物种（绿藻、节肢动物、线虫、无脊椎动物和真菌）。在真核生物生长、发育和生理过程中，uORF通常作为反式因子对mORF表达起调节器作用，例如，在植物蔗糖、多胺、磷脂酰胆碱，以及甲基转移酶反应中，相当大比例的uORF参与介导mORF的翻译调控。     

内蒙古经济空间结构演变及特点

近年来,中国民族地区经济平稳快速增长,为了更好的说明民族地区经济增长的动力,文中以内蒙古自治区1990-2009年近20年的相关数据,分析了内蒙古经济空间结构演变,并从内蒙古工业布局演变和工业化影响因素等方面分析了经济空间结构演变机制及特点。结果表明:1990年以来,内蒙古经济初显空间集聚效应,内蒙古经济空间结构与工业化、矿产资源分布状况存在内在的联系和耦合关系,其中工业发展,尤其是矿业是内蒙古经济增长的主要动力,也是经济空间结构形成和演化的重要原因。     

Genetic Diversity and Global Distribution of Citrus tristeza virus （CTV） Strains

Citrus tristeza virus （CTV）, the most devastating viral pathogen in citrus, causes tremendous economic losses to citrus industry worldwide. The CTV isolates exhibit variable pathogenicities on their ho...     

差异演化算法改进与应用

提出了一种改进的差异演化算法MDE(modified differential evolution algorithm),该算法首先对差异演化算法的缩放因子进行混沌计算,减少了用户参与程度,平衡了算法的收敛速度与全局搜索能力;其次引入灾变因子,对群体中的个体进行小概率淘汰,同时又有新的个体加入,从而提高了群体多样性,提高了算法的全局搜索能力.仿真实验与工程实例表明,该算法具有较好的全局搜索能力.     

田径内涵嬗变与项目沿革新探索

对奥运会田径比赛项目、奥运历史上曾举行过的项目、田径技术、场地、规则、比赛成绩等方面的演变与发展进行新探索。