The Study of Heterogeneous Rural-Urban Migrants’Different Urban Choice

随着我国城市化深入发展，劳动力流动越发频繁。劳动力个体的城市选择可能会影响城市人力资本结构进而影响城市经济的发展。厘清劳动力城市选择差异及动因具有积极的现实意义。本文运用2007年中国家庭收入调查数据（CHIP2007流动人口部分）及城市层面的宏观数据，分析异质性农民工城市选择的差异及动因。不同于以往研究，本文的着眼点在于已确定外出的农民工选择去什么样的城市以及在不同的城市对个体收入有怎样的影响。研究结果显示：（1）不同技能的农民工有不同的城市选择，低技能农民工倾向选择中大规模（500万人口以下）的城市，中技能农民工更有可能选择超大城市（1000万以上人口），而高技能农民工可能更倾向选择介于二...With the deeply development of China's urbanization, labor mobility increasingly frequent.Labor’urban choice may affect human capital structure and then affect the development of urban economy.So, clarifying their urban choice motivation has positive practical significance.This paper use Chinese Household Income Survey data 2007 and city level data,to find out selection differences and the reason ...学位：经济学硕士院系专业：经济学院_西方经济学学号：1532014115213

The Phylogeny Tree Reconstruction Based on the Usage Frequencyof Codons and Corresponding Complementary Codons

为了更深入地了解密码子与互补密码子使用相关的内涵,70个单细胞和多细胞生物被更进一步的分析。结果得到70种细胞生物具有较高的相关系数平均值(0.5101,标准差是0.1389),表明密码子与其互补密码子使用间确实存在正的使用相关联系,进一步地支持了以前的结果。此外,通过对70个单细胞和多细胞生物在基于密码子与互补密码子使用频率差异,以及配对频率的高低信息的分析基础上,绘制进化树,得到的进化树与传统的进化树非常接近。The hypothesis that a codon bias usage is identical to its complementary codon usage preference has been investigated by using the relationship analysis of codons vs their complementary ones among 70 organisms. Significantly positive usage correlations between codons and their complementary ones were found and its implication in biology was also analyzed. The codoncomplementary codon tree was further built, which fairly exhibited the evolutionary relationship of these organisms. The results not only demonstrated the validity of our hypothesis,but also manifested the usefulness of correlation analysis in studying on codon usage pattern and molecular evolutionary mechanisms of organism.ThisworkwassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina(No.60305001)andagrantfromtheScienceandTechnologyMinistryofChina(PreliminaryStudyonFunctionalGenomeSystematics)(No.2001CCA01400)

基于递归系统模型的宫颈癌患者住院费用影响因素分析

目的分析宫颈癌患者住院费用的影响因素,为控制住院费用提供依据。方法收集厦门市某三甲医院2012 -; 2014年入院接受治疗且信息完整的宫颈癌患者的一般情况和住院费用等资料,通过递归系统模型分析各因素的直接与间接效应,计算总效应,找出费用控制的关; 键性因素。结果共纳入524例宫颈癌患者,其中医保患者占49.8%,首诊年龄的中位数为48岁,住院天数的中位数为28天,总费用的中位数为43841; .06元。支付方式、转移情况对总费用仅有直接效应,同时治疗其他疾病、MRI检查仅有间接效应;; 临床分期、治疗方案、手术方式既有直接效应又有间接效应;; 治疗方案的总效应值最大。结论宫颈癌住院费用受到多个因素的直接效应、间接效应、直接和间接效应的影响,其中以治疗方案的影响最大。可通过规范化制定治疗; 方案控制宫颈癌的住院费用。厦门大学大学生创新项目基

Correlation Analyses of Codons and Corresponding Complementary Codons Usage

遗传密码是基因与蛋白质进行信息对接的桥梁,研究不同进化阶层生物的密码子与互补密码子的使用规律是揭示物种进化的一种重要途径。为了阐明不同生物和细胞器基因密码子与互补密码子使用之间的内在联系及其在进化中的意义,作者选取了44种细胞生物、16种病毒、40种线粒体和20种叶绿体的基因密码子与互补密码子数据,并进行关联分析。结果显示:(1)无论是古细菌,真细菌,病毒,真核生物还是两类细胞器,它们的密码子与互补密码子的使用频率大多表现为显著或极显著正相关;(2)不同生物和细胞器基因密码子与互补密码子使用频率之间相关程度也存在明显的异质性。细胞生物和两类细胞器基因密码子与互补密码子使用的高度一致性反映了它们可能具有共同的起源,显著的异质性则反映了它们分别经历了不同的进化选择压力。密码子与互补密码子的使用相关程度不仅能被用作为测量物种进化过程中所经历选择压力的指标,而且也能被用作为碱基摆动和修饰的指示器。此外,文中还对生物进化早期存在DNA双链同时具有编码基因功能的可能性进行了讨论。To reveal the relationship between codons and corresponding complementary codons usage, the data of codon and corresponding complementary codon usage from 44 cellular organisms, 16 viruses, 40 mitochondria and 20 chloroplasts were analyzed. Significant correlations between codons and corresponding complementary codons usage were found in the majority of the studied subjects except viruses, albeit there was also significant heterogeneity among them. The degree of correlation between codons and corresponding complementary codons usage may be used as an index not only for measuring the degree of selection force during organism evolution, but also for exploring the degree of anticodons' modification and wobbling-pairing with corresponding codons within organisms. In addition, it is also discussed that the two strands of DNA may have simultaneous coding function in the early stage of organism evolution.国家自然科学基金项目((No 60305001)资助