Spatial and seasonal variations in bacterial communities of the Yellow Sea by T-RFLP analysis

Four typical coastal sites (rocky shore, sandy shore, mud flat shore, and artificial harbor) at the Yellow Sea were chosen to investigate the spatial and seasonal variations in bacterial communities. This was accomplished by using terminal restriction fragment length polymorphism (T-RFLP) analysis of PCR amplified 16S rDNA fragments. Two kinds of tetrameric restriction enzymes, HhaI and MspI, were used in the experiment to depict the bacterial community diversity in different marine environments. It was found that the community compositions digested by the two enzymes separately were different. However, the results of bacterial community diversity derived from them were similar. The MDA analysis results of T-RFLP profiles coming from HhaI and MspI both exhibited a significant seasonal community shift for bacteria and a relatively low spatial variation among the four locations. With HhaI as the sample, the pair wise T-tests also revealed that variations were minor between each pair of marine environments, with R ranging from 0.198 to 0.349. However, the bacterial community structure in the mud flat site depicted a larger difference than each of the other three sites (R ranging from 0.282 to 0.349).     

我国能源发展的环境约束分析

能源生产与消费是造成大气环境污染与生态环境破坏的重要原因,而环境容量的过度使用,又会反过来约束能源的发展.通过分析近5年来我国能源发展的供需状况、能源经济形势、开发布局,以及能源开发环境破坏、大气环境容量、二氧化碳排放状况等,发现了我国能源发展与环境保护之间存在的问题,并总结了我国能源发展主要面临的四个方面的环境约束.全面和系统地梳理这些环境约束条件,有助于实现能源的可持续发展,并且为进一步改革现有的能源环境政策提供参考.     

水资源约束下西北干旱区城市扩张特征与变动趋势分析——以西陇海兰新经济带城市为例

论文以西北干旱区陇海兰新经济带城市为例,分析了城市水资源利用状况及其短缺程度,认为绝大多数城市“缺水又费水”,城市发展具有明显的“旱生性”。在水资源约束下,西陇海兰新经济带城市的发育程度远远落后于东部地区城市,也落后于全国城市平均水平,略好于西部地区城市,但明显好于西北地区城市,城市扩张的总体特征表现为以总量扩张为主,“农转非”空间和用地拓展空间大,以高耗低效扩张为主,水土资源投入产出效益普遍低下,城市发展处在主要依靠资源开发拉动经济增长的低级阶段,扩张质量有待提高。城市发展具有明显的外部推动性。未来20a,在水资源短缺的继续约束下,经济带城市扩张步伐将比较缓慢,扩张幅度将不会有大的变化。表现为将净增城市非农业人口6.31×106人,城市化水平将提高到35.97%,20a共净增7.21%,特大城市数量将保持西安、兰州和乌鲁木齐3个不变;大城市从无到有,将建成宝鸡、咸阳、铜川、天水、石河子和库尔勒6个;中等城市数量将会显著增加,由2000年的10个增加到2020年的14个,在不考虑“县改市”的前提下,小城市的数量将会进一步减少。为了确保经济带沿线城市的有序扩张,建议在城市建设过程中以人为本,以水为生命线,以经济发展为动力,以城市规划为法定依据。     

Ambient levels of atmospheric carbonyls in Beijing during the 2008 Olympic Games

The measurements of atmospheric carbonyls concentrations in Beijing were conducted from 12 July to 8 October, 2008, covering the periods of the 2008 Olympic Games and Paralympic Games. Six carbonyls, including formaldehyde, acetaldehyde, acetone, butyraldehyde, valeraldehyde, and hexaldehyde, were identified in all air samples. The total average concentrations of these carbonyls before, during, and after traffic restriction were (48.1 ± 15.2), (36.6 ± 14.5) and (23.4 ± 12.3) μg/m3, respectively. Compared with the period after traffic restriction, the distinct high concentrations of the carbonyls before and during traffic restriction were primarily ascribed to the remarkable contribution of photochemical reactions. With respect to our previous investigation in the summer of 2005, the reductions of formaldehyde, acetaldehyde and acetone during traffic restriction period were about 64%, 47% and 27%, respectively, indicating that the air cleaning actions adopted by the Chinese government for the two games were efficient. The lowest levels of atmospheric carbonyls and the extremely high composition proportion of acetone after the traffic restriction were mainly attributed to the long-term effect of the control measures for the two games.     

构建农民收入增长的长效机制

“三农问题”是关系国家经济和社会发展全局的问题，其核心是农民收入增长，农民收入增长的关键是构建收入增长的长效机制。本文通过分析中国农民收入的现状，从制度视角分析农民收入增长缓慢的土地制度、税费制度、金融体制、公共品供给体制以硬社会保障制度等方面原因．在此基础上提出构建中国农民收入增长长效机制的制度框架。     

资源环境约束下构建区域技术创新决策管理体系研究

当前区域经济社会发晨面临日益突出的资源环境约束阎题，区域技术创新体系建设和技术创新能力提升。是缓解资源环境压力、实现经济社会全面协调可持续发晨的根本途径。区域技术创新决策管理体系是整个技术创新体系的重要一环。本文在阐述技术创新重要作用等基础上。提出了在资源环境约束下，构建区域技术创新决策管理体系的主要措施。     

Effect of excessive cadmium chloride on the plasmids of E. coli HB 101 in vivo

１ＩｎｔｒｏｄｕｃｔｉｏｎＣａｄｍｉｕｍｉｓｏｎｅｏｆｉｍｐｏｒｔａｎｔｅｎｖｉｒｏｎｍｅｎｔａｌｐｏｌｕｔａｎｔｓ．Ｉｔｉｓｖｅｒｙｔｏｘｉｃｔｏｂｉｏｌｏｇｙ（Ｂａｒｂｅｒ，１９９４；Ｃｏｌａｒｄ，１９９０；Ｇｏｙｅｒ，１９９５；Ｎａｓｓｉｒｉ，...     

棉铃虫核多角体病毒基因组限制酶酶切分析及其多角体基因的定位

应用１１种限制性内酶ＢａｍＨⅠ、ＢｓｔＥⅡ、ＥｃｏＲⅠ、ＥｃｏＲⅤ、ＨｉｎｄⅢ、ＫｐｎⅠ、ＰｓｔⅠ、ＳａｌⅠ、ＳｓｔⅠ、ＸｂａⅠａⅠ和ＸⅠⅠ和ＸｈｏⅠ分别将中国棉铃虫核多角体病毒（单粒包埋ＨａＳＮＰＶ）湖北株基因组Ｄ组ＤＮＡ酶切为１０、１２、２２、２１、１３、６、６、４０、６、２１、６个片段，并求得基因组大小平均为１什什Ｍｒ≈７９．１×１０６．以家委核多角体病毒ＢｍＮＰＶ多角体基因为探针，利用Ｓｏｕｔｈｅｒｎ杂交技术将病毒多角体基因定位在ＳａｌⅠ４．２×１０３ｂ左右的片段上．与棉铃虫核多角体病毒其它株系酶切图谱比较结果表明，本株病毒与上海等株系及美洲棉铃虫核多角体病毒ＨａＳＮＰＶＥｌｋａｒ株系酶切图谱相似，它们之间的条带数和大小差异较小，而与已发现的所有多粒包埋型病毒ＨａＳＮＰＶ酶切图主谱差异较大．据此认为ＨａＳＮＰＶ和ＨａＭＮＰＶ属于基因型不同的两类病毒，而ＨａＳＮＰＶ不同分离株的同源性很高     

人力资本效能的彰显:激励与约束

人力资本是生产要素中最活跃和最特殊的要素，它的激励与约束问题极为精巧、复杂．本文通过对人力资本激励与约束问题的考察，结合我国体制内企业运营的实践，初步探讨了人力资本激励与约束的机制．     

Altered levels of insulin-like growth factor binding protein proteases in preeclampsia and intrauterine growth restriction

Intrauterine growth restriction (IUGR) and preeclampsia (PE) are leading causes of perinatal and maternal morbidity and mortality. Many studies have found association between low levels of insulin-like growth factor binding protein (IGFBP) proteases in the first trimester maternal circulation and the risk of subsequent development of PE and/or IUGR. These results are generally interpreted to reflect decreased production of the proteases by the placenta, leading to reduced proteolysis of IGFBPs and lower free levels of insulin-like growth factor (IGF), resulting in diminished feto-placental development. However, the association between low circulating levels of placental proteins early in pregnancy and the subsequent development of IUGR and/or PE could be due to low exchange in the placenta and not due to reduced production. In contrast, late in pregnancy, the circulating levels of these proteins and their expression in the placenta are often elevated in PE, which may reflect upregulation to compensate for abnormal placental development, that is an adaptive mechanism to increase IGFBP proteolysis, increase local IGF levels and promote feto-placental growth. Further research into the biological mechanisms underlying these associations will aid the identification of high-risk pregnancies and the development of therapeutic targets for diseases for which there are presently no preventative measures. Copyright © 2010 John Wiley & Sons, Ltd.