216 research outputs found
Effects of environmental tax reforms in a small open economy
文章在一般均衡模型框架下考察了事先存在税收"扭曲"的"次优环境"中,环境税改革对小型开放经济的效应,并利用重庆市的宏观经济数据对模型结论进行模拟。结果发现:环境税有利于改善环境质量,但同时也加重了原本的经济扭曲,环境与经济效率之间存在替代关系,从而表明"双重红利"假说不成立;"次优环境"下的最优环境税低于"最优环境"下的最优环境税率(庇古税率);对重庆市宏观经济数据的模拟却表明环境税对家庭和企业的影响具有显著的差异性。By virtue of general equilibrium model, the paper evaluates the effect on environment tax on small open economy in the " sub-optimum environment" where " distortion" pre-exists, and utilizes the macro economic data of Chongqing Municipality to perform simulation on the model conclusions. As demonstrated by the model analysis results, environmental taxes are favorable to improve environment quality, and meanwhile the original economic distortion is aggravated. Actually, a kind of substitution relation exists between environment and economic efficiency, therefore, it demonstrates that the " double dividend " hyphothesis fails, and the optimum environmental tax under sub-optimum environment is lower than Pigou tax rate. The simulation of the macro economic data of Chongqing municipality demonstrates that environment tax has distinctive influence differences on families and enterprises.国家社会科学基金重大项目“中国新型城镇化包容性发展的路径设计与战略选择”(12&ZD100));国家社会科学基金项目“不同市场结构下我国环境税效应研究”(13BJY149);; 重庆市社会科学规划(培育)项目“环境税‘双重红利’效应研究”(2013PYYJ16);; 中央高校基本科研业务专项资金项目“中国环境税改革路径研究—基于OECD国家经验”(SWU1409126);“环境税防控农业面源污染机制研究”(SWU1509307
Cloning and expression analysis of lipopolysaccharide-induced TNF-α(LITAF) of Japanese scallop (Mizuhopecten yessoensis)
脂多糖诱导的肿瘤坏死因子(lIPOPOlySACCHArIdE-InduCEd Tnf-AlPHA fACTOr,lITAf)是一类重要的炎症细胞因子,在先天性免疫系统中发挥重要的介质作用。文章根据虾夷扇贝lITAf基因EST序列,应用rACE技术克隆了虾夷扇贝lITAf全长CdnA,对序列及编码的氨基酸进行生物信息学分析。结果显示,该基因CdnA全长1 551 bP,其5′非编码区包含76 bP,3′非编码区包含1 001 bP;开放阅读框(Orf)为474 bP,编码157个氨基酸,氨基酸序列中存在一个保守的lITAf结构域;理论分子量16.99 kdA,等电点为6.24。lITAf基因序列为3 698 bP,由3个外显子和两个内含子组成。利用实时荧光定量PCr技术分析lITAf在虾夷扇贝不同组织、不同胚胎发育阶段以及鳗弧菌(VIbrIO AnguIllAruM)刺激后各时间段的表达情况。结果表明:lITAf基因在所检测的6个成体组织中均有表达,其中肾脏的表达量最高;胚胎发育的7个时期中,担轮幼体时期表达量最高;菌刺激36 H实验组与对照组的表达量差异大。lITAf基因是lITAf家族的一员,推测lITAf基因参与虾夷扇贝的先天性免疫反应。The lipopolysaccharide-induced TNF-alpha factor(LITAF) is an inflammatory cytokine,which plays an important role in innate immunity system.Based on the expressed sequence tag(EST) of Japanese scallop(Mizuhopecten yessoensis),the cDNA of LITAF gene was amplified using rapid amplification of cDNA ends(RACE) approach.Results showed that the full-length cDNA of LITAF is 1 551 bp consisting of a 5′ untranslated region(UTR) of 76 bp,a 3' UTR of 1 001 bp,and an open reading frame(ORF) of 474 bp encoding a polypeptide of 157 amino acids,and there is a conserved LITAF domain in amino acid sequences.The estimated molecular mass is 16.99 kDa and the theoretical isoelectric point is 6.24.The total length of LITAF is 3 698 bp,which includes three exons and two introns.Real-time quantitative PCR was carried out to measure LITAF mRNA expression in adult tissues and monitor mRNA expression patterns during embryonic development after bacteria(Vibrio anguillarum) challenged.The expression level of LITAF mRNA was detected in all the adult tissues with the highest in the kidneys.The trochophore owns the highest expression level of LITAF in embryonic development.LITAF expression showed significant difference(P<0.01)between the control and bacteria challenged specimens at 36 h.These results suggest that the LITAF should be a member of the LITAF family that perhaps involved in the innate immune response of Japanese scallop.国家海洋公益性行业科研专项(编号:200805037);国家自然科学基金项目(编号:31140073)资
急性脑卒中患者的记忆障碍与肽类物质的关系
本实验对12例缺血性脑血管病(ICVD)患者及12例对照者和12例正常健康对照者进行了临床记忆量表检查,并测定了患者及对照者的CSF、VIP及SS含量。结果:(1) ICVD患者的记忆总分及MQ均显著低于两个对照组;分项测试中联想学习,图像自由回忆成绩亦显著降低。(2) ICVD患者CSF SS含量显著低于对照组。(3) ICVD患者CSF SS含量与MQ呈显著正相关。本结果提示ICVD患者有不同程度的记忆障碍,SS与记忆有关,测定CSF SS对患者记忆状况的判断有参考价值
The properties of action potential and sodium-calcium exchange tail current of rabbit right ventricular outflow tract myocytes
目的研究兔右室流出道(rVOT)心肌细胞动作电位及钠钙交换尾电流(InCX,TAIl)相关特性,探讨源于rVOT室性心律失常的发生机制。方法采用全细胞膜片钳技术记录兔右室(rV)游离壁和rVOT心肌细胞的动作电位,在不更换细胞及电极内液情况下连续记录InCX,TAIl,对比分析两者动作电位和InCX,TAIl特性。结果兔rVOT心室肌细胞动作电位复极时程(APd)的变异程度大于rV游离壁心肌细胞。在rVOT心肌细胞记录到早期后除极及显著延长的APd。动作电位显著延长及后除极的rVOT心肌细胞所对应的InCX,TAIl到达峰值时程较动作电位正常的细胞延迟,并且电流强度大于rV游离壁对照组心肌细胞(P<0.05)。结论 rVOT心肌细胞APd变异程度大,而且APd显著延长的rVOT细胞InCX,TAIl到达峰值时程延迟及相应电流显著增大,这是rVOT部位好发触发活动的重要机制。Objective To explore the electrophysiological basis of arrhythmogenesis in right ventricular outflow tract(RVOT) myocytes of rabbit heart.The properties of action potential and sodium-calcium exchange tail current(INCX,tail) in rabbit RVOT cells were observed.Methods Patch-clamp technique was used to measure INCX,tail and action potential in single myocytes obtained by enzymatic dispersion of rabbit ventricle.Results Marked variability of action potential repolarization was observed in rabbit RVOT cardiomyocytes.The events of early afterdepolarization(EAD) and marked action potential duration(APD) extension were recorded in RVOT cells.The peak of INCX,tail was delayed significantly in marked APD extension RVOT cells compared to RV free wall cells,and the amplitude of INCX,tail in the former was larger than the latter ones(P<0.05).Conclusion In rabbit RVOT cardiomyocytes,prolonged APD might be the induction factor of delayed afterdeporization and EAD genesis.Under this precondition,the late-peaking and larger amplitude of INCX,tail in RVOT cells might play pivotal role in the mechanism of RVOT arrhythmogenesis.厦门市卫生局资助项目(No.A0000258
1978~2008年中国湿地类型变化
分别基于美国陆地卫星(Landsat MSS/TM/ETM+)和中巴资源卫星(CBERS-02B)影像数据,以人工目视解译为主,完成了中国1978~2008年4期(基准年分别为1978,1990,2000和2008年)湿地遥感制图,并进行了大量的室内外验证.在此基础上,对我国湿地现状及近30年来湿地变化进行了初步分析,得到以下主要结论:(ⅰ)截止2008年,中国湿地面积约为324097km2,其中以内陆沼泽(35%)和湖泊湿地(26%)为主.(ⅱ)1978~2008年,中国湿地面积减少了约33%,而人工湿地增加了约122%.过去30年里湿地减少的速度大幅降低,由最初5523km2/a(1978~1990年)降为831km2/a(2000~2008年).(ⅲ)减少的自然湿地(包括滨海湿地和内陆湿地),其类型变化由湿地向非湿地转化的比例逐渐降低.初期(1978~1990年)几乎全部(98%)转换为非湿地;在1990~2000年间减少的自然湿地约有86%转化为非湿地,而在2000~2008年,这一比例下降为77%.(ⅳ)气候变化和农业活动是中国湿地变化的主要驱动因素,湿地变化在中国分为三大不同特征区域,即西部三省/自治区(西藏、新疆和青海)、北部两省/自治区(黑龙江和内蒙古)和其他省市区.其中西部区域尤其是青藏高原,湿地变化的驱动因子以气候增温为主;新疆湿地由于气候增温和农业活动共同作用造成变化不大.北部省/自治区的湿地变化则主要由农业活动引起;而其他省市区的湿地变化几乎完全受控于人类的农业经济活动
The World Federation of Democratic Youth and Bruno Bernini's encounter with Mao's China
This paper examines the role played by adult-led youth groups in providing avenues for early encounters between Italian and Chinese Communists in the '50s. In particular, it focuses on the links built up within international organisations linked to the Soviet-sponsored peace movement at a time when direct exchange between the Italian and Chinese Communist parties had yet to start. Relying on a large variety of primary and secondary sources, some of which have never been used before, I provide evidence of how participation in Soviet-led international organisations made early political contacts and interactions possible. The focus is on Bruno Bernini, whose personal experience in China is examined within the context of the World Federation of Democratic Youth's policies and initiatives in the early and mid-'50s
植物叶蜡正构烷烃分子分布特征与植被类型的关系
正构烷烃是自然界中广泛分布的生物标志化合物,其链长及主峰碳常被用来指示古气候 和古植被变化。我们测定了贡嘎山、太白山和黄土高原地区 65 个植物样品叶蜡正构烷烃的分子 分布特征,并对 1232 个木本和草本植物(包括本实验的 65 个样品)的正构烷烃比值进行统计。 研究表明:木本和草本植物正构烷烃中 C29 和 C31 含量基本均较高,其相对丰度变化很大,其中 木本植物主峰碳为 C27 或 C29 的占 61.9%,草本植物主峰碳为 C31 的占 65.2%。三元相图分析也表明, 木本和草本植物 C27、 C29 和 C31 的相对丰度重叠部分较大,而以 C27、 C29 和 C31 为标准对木本和 草本植物进行判别分析的准确度为 69.5%。研究结果表明 C27、 C29 和 C31 主峰碳丰度不能作为区 分木本和草本植物的有效指标。同样,利用 C31/C29 或 C31/C27 也不能够区分木本和草本植物。我 们发现以 C33/(C33+C29)=0.30 为标准对木本和草本植物进行判别分析的准确度为 81.5%,而以 C33/ (C33+C27)=0.20 为标准对灌木和草本植物进行判别分析的准确度为 85.7%,表明某些正构烷烃比值 可能具有区分木本和草本植物的潜力,但结合 1232 个木本和草本植物数据统计发现,正构烷烃 比值不能有效区分木本和草本植物。因此,应谨慎利用正构烷烃主峰碳及比值进行植被恢复,这 可能为古气候和古植被重建提供必要的参考。</p
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