Pitfalls in the analysis of ancient human mtDNA

The retrieval of DNA from ancient human specimens is not always successful owing to DNA deterioration and contamination although it is vital to provide new insights into the genetic structure of ancient people and to reconstruct the past history. Normally, only short DNA fragments can be retrieved from the ancient specimens. How to identify the authenticity of DNA obtained and to uncover the information it contained are difficult. We employed the ancient mtDNAs reported from Central Asia (including Xinjiang, China) as an example to discern potentially extraneous DNA contamination based on the updated mtDNA phylogeny derived from mtDNA control region, coding region, as well as complete sequence information. Our results demonstrated that many mtDNAs reported are more or less problematic.Startim, from a reliable mtDNA phylogeney and combining the available modern data into analysis, one can ascertain the authenticity of the ancient DNA, distinguish the potential errors in a data set, and efficiently decipher the meager information it harbored. The reappraisal of the mtDNAs with the age of more than 2000 years from Central Asia gave support to the suggestion of extensively (pre)historical gene admixture in this region.     

基于承载力的矿区生态经济系统演化分析

矿区生态承栽力和生态弹性力与矿区生态经济系统演化密切相关。分析了矿区生态承栽力和矿区生态弹性力的内涵，以矿区生态承栽力、生态弹性力作为矿区生态系统的状态因子，矿区资源经济开发活动强度、资源经济开发速度作为矿区经济系统的状态因子，建立矿区生态经济系统演化的动力学模型。对环境资源掠夺性经济开发、环境保护性经济开发两种开发方式进行计算机模拟，结果显示人类经济开发活动方式对矿区生态经济系统演化趋势具有重要影响，并提出应用技术手段、经济手段和社会手段对矿区生态经济演化系统进行调控。     

经济因素在文化传播中的强势作用

I.The theory basis for the thesisThe dominated position of the economy.From the aspect ofMarx’s philosophy and plutonomy,the world is substantial.Heclaimed that substance takes up the first characteristic,superiorto all other aspects of the world.“As the basic economyactivity,Material production activity has the most fundamentalfunction for human being to survive.Economy activities includefour parts,namely,production,distribution,exchange andconsumption,in which most of the human being’s …     

重庆市环城游憩带的形成及发展

介绍了环城游憩带的国内外研究现状,并以重庆市为例,给出了重庆市环城游憩带形成的有利条件,将主要的旅游资源分成地文景观、水域风光、生物景观和建筑与设施4类;对各类资源的分布特征进行了总结,指出了重庆市环城游憩带发展仍然存在交通拥挤、环境质量差、服务态度较差、宣传力度不足等问题,并提出了完善基础设施、开拓出游方式等具体解决措施。     

210国道对牛背梁保护区羚牛东西扩散影响的研究(Ⅱ)——210国道车流量变化规律

2000年10月—2001年10月,采用定点观测的方法,对210国道保护区段每日04:00—22:00时的流动车辆进行了观测,总计流动车辆65 755辆,按观测日数计算,日均车流量782.8辆,平均1.37辆/2 min.每日15:00时的车流量最大,06:00时的车流量最少;主要集中在09:00—22: 00时,而以14:00—18:00时最为集中;每日的车流量变化可以分为四个阶段:即04:00—07:00时、07:00—13:00时、13:00—19:00时和19:00—22:00时,其中13:00—19:00时最大,19:00—22:00时次之,04:00—07:00时最小.     

中部地区经济发展与人力资源开发关系研究

中部六省是我国重要的工业、农业和能源基地,但近年来"中部塌陷"给宏观经济运行带来隐患。本文结合"中部崛起"战略构想,从区域经济的角度出发,运用新增长模型,分析中部地区经济发展与人力资源的相互关系,并给出中部崛起战略下人力资源开发的对策。     

～4.1 Ga xenocrystal zircon from Ordovician volcanic rocks in western part of North Qinlin80rosenic Belt

High-precision U-Pb dating by in situ LA-ICP-MS yields an age of 4079±5 Ma for a xenocrystal zircon from Ordovician volcanics of the Caotangou Group in western part of the North Qinling Orogenic Belt. As a result, the North Qinling Orogenic Belt becomes one of a few localities in the world that contain Hadean age records （4276±6 Ma and 4404±8 Ma detrital zircons from Jack Hill of the Yilgarn craton, 4016 Ma Acasta gneisses of the Wopmay Orogeny and Burang quartzite with detrital zircon of 4103 Ma in Tibet）. It is also the first report of the Hadean age in Phanerozoic volcanics. The finding of the 4.1 Ga xenocrystal zircon provides not only the geochronological record of the oldest crustal materials in China, but also the condition for further search for rocks forming in the region during the early time of the Earth＇s evolution. Thirty-six zircon U-Pb dates from the Ordovician volcanic rocks are subgrouped into seven generations that represent different tectono-magmatic events in the North Qinling Orogenic Belt. Among them, two periods of 0.9--1.5 Ga and 0.4--0.5 Ga are consistent with Mesoproterozoic and Early Paleozoic orogenies, respectively.     

论经济法的历史使命

经济法是市场经济内在矛盾的必然产物，同时也是法对经济关系调整之历史发展的逻辑结果。自诞生之日起。经济法就承担起了民法和行政法无法承担的克服和弥补“市场失灵”和“政府失灵”等双重历史使命。经济法对构建我国的社会保障制度、维护公平竞争及社会主义和谐社会的建设有着深远的意义。     

双转型背景下东莞市人才引进策略研究

随着东莞由"双优势效应"逐渐转化为"双边缘化困境",东莞市提出了经济社会双转型.东莞双转型的关键是人才.而现阶段人才问题的关键又是如何从国内外引进东莞双转型所急需的各种人才.分析了双转型以来东莞市人才的现状及东莞市引进人才中存在的问题,在此基础上提出了双转型背景下东莞市引进人才的策略.