588 resultados para 1044
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不同尺度空间下的自然环境背景不同,生态因子性质、生态系统整体性特征不同,其生态功能区规划方法和生态建设途径也就显著不同。沈阳作为东北老工业基地的中心城市,为解决城市扩张产生的一系列生态问题,为今后发展提供较高的生态服务功能,开展了生态功能区建设规划,通过沈阳城市东部生态功能保护区建设规划,对小尺度空间的城市生态功能区规划方法进行了探索。
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A manganese molybdenum phosphate, (NH3CH2CH2NH3)(10)(H3O)(3)(H5O)Na-2[MnMo12O24(OH)(6) (PO4)(4)(PO3OH)(4)][MnMo12O24 (OH)(6)(PO4)(6)(PO3OH)(2)]. 9H(2)O, has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. The structure of this compound may be considered to be two [Mo6O12(OH)(3)(PO4)(2)(HPO4)(2)](7-) units bonded together by a manganese atom, although several P-O groups are not protonated on account of coordination to a Na+ cation. One-dimensional tunnels were formed in the solid. A probe reaction of the oxidation of acetaldehyde with H2O2 using this compound as catalyst was carried out in a liquid-solid system, showing that the manganese molybdenum phosphate has high catalytic activity in the reaction.
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Superconductor Y-Ba-Cu-O mixed oxides were synthesized and their catalysis in phenol hydroxylation was studied too. Results show that, Y2BaCuO5 has better activity than that of YBa2Cu3O7-x, With the catalysis study of another mixed oxide La2CuO4 a conclusion that AO structure unit is the key for mixed oxides to have high activity in phyenol hydroxylation was drawn. Meanwhile, the effects of reaction temperature, medium and medium (water) pH on phenol hydroxylation catalyzed by Y2BaCuO5 and the stability of the mixed oxides were also studied.
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本论文采用扩增片段长度多态性(AFLP)技术对牙鲆Paralichthys olivaceus群体和夏鲆Paralichthys dentaus 群体进行了种群鉴定和遗传结构分析。共用8 对引物对两个群体(每个群体30 个个体)进行了分析。总共产生了379 个条带,条带大小在60-1000bp。牙鲆与夏鲆的遗传多态性分别为53.83%和22.22%。牙鲆群体的多态位点数显著低于夏鲆群体。牙鲆群体和夏鲆群体种的特异条带分别为27.3% 和 29.61%。两群体平均杂和度分别为0.0701 和 0.1556,香农氏多态指数分别为0.1044 和0.2387。群体内平均遗传距离分别为0.0705 (0.0214 到0.1377)和0.1656 (0.0629 到 0.2338),两群体间的平均遗传距离为0.6328。 AFLP 技术是进行种间群体结构分析的一个很好的分子标记方法,对牙鲆和夏鲆亲本群体进行遗传背景析为今后的杂交育种阐明种间杂交的遗传机理奠定基础。 在本论文中我们采用5×8 因子交配设计建立了牙鲆P. olivaceus(♀)× 夏鲆P. dentaus(♂)杂交家系,对生长相关性状的遗传力进行分析。所有家系都混合养殖在同一养殖池中,40 日龄,在养殖池中随机采集600 个个体,测量体长,体宽,体重等数量性状;然后提取杂交子代DNA 进行家系的鉴定。首先从牙鲆的微卫星中筛选了在牙鲆、夏鲆以及杂交子代扩增多态性较好的10 对微卫星引物(Po1, Po13, Po20, Po35, Po42, Po48, Po56, Po58, Po91, Poli 23TUF)。我们采用了三对引物对600 个个体进行了家系鉴定,共有400 多个体鉴定出自己的亲本,成功率达到80%以上。基于以上结果我们认为微卫星标记可以做为一个有效的标记来代替现实的物理标记,并且可以在子代的早期进行亲本的鉴定。 在养殖过程中,我们对自交和杂交家系生长状况进行了跟踪分析,在181刘清华 牙鲆(♀)×夏鲆(♂)分子遗传学及数量遗传学研究 博士学位论文II日龄之前杂交鲆体长和体重均为未表现出杂种优势,杂种优势率值始终为负值,但是绝对值在逐渐减小。从196 日龄之后杂交鲆杂种优势开始表现出来,并且在196 日龄之后杂种优势率显著的增加。256 日龄体长杂种优势率为14.29%,体重杂种优势率为59.78%, 271 日龄体长杂种优势率达到27.36%,体重杂种优势率为 102.32%。 本研究对杂交鲆在40 日龄的体长,体高、尾柄长、尾柄高,以及全长和体重的遗传力进行了估计,5 个性状的体长半同胞遗传力h2 S 为0.00146-0.719,5个性状的全同胞遗传力h2D 为0.00121-0.632,5 个性状的半同胞和全同胞的平均遗传力h2SD 为0.001335-0.6755。其中全长的遗传力最大。实验结果说明对早期幼鱼进行体长、体重等性状实施选育策略可能会显著影响后期杂交鲆的生长。
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利用AFLP和微卫星标记,以凡纳滨对虾F1全同胞家系为作图群体,构建了凡纳滨对虾的雌性和雄性遗传连锁图谱并对生长相关性状体长和体重进行了QTL分析。利用经过筛选的108对AFLP引物组合,对亲本和94个子代个体进行了分离分析。共得到2041个多态AFLP标记(1:1分离)。平均每个引物组合产生20个多态片段。有826个AFLP标记偏离孟德尔遗传(40.5%, P<0.05)。所筛选的100个微卫星标记中有30个在家系中有作图信息,分别有24个和20个位点可以用于母本和父本的作图。对父母本β-1,3-葡聚糖结合蛋白(BGBP),脂多糖和葡聚糖结合蛋白(LGBP)和蜕皮抑制激素(MIH)等基因片段进行序列分析得到一些可用于构建连锁图谱的SNP标记。 对所有的分离标记进行了连锁分析,分别绘制了凡纳滨对虾的雌性和雄性连锁图谱。雌性连锁图谱的框架图有319个遗传标记组成,分布于45个连锁群,其中AFLP标记300个,微卫星位点18个,性别标记一个,连锁群长度从29.5cM到260.0cM, 每个连锁群含4-16个标记。图谱长度为4134.4 cM, 各连锁群平均图距在7.6到25.9 cM之间,总平均图距为15.1 cM。有267个标记(含14个微卫星)整合到雄性框架图上。 雄性框架图也含45个连锁群,长度从14.2cM到161.1cM, 图谱长度为3220.9 cM, 各连锁群平均图距在4.1到25.5 cM之间,总平均图距为14.5 cM。 作图群体所有个体的性别均作为标记整合到雌雄分离信息中,在94个F1个体中,54个为雌虾,40个是雄虾。在雌性图谱第29连连锁群上,性别与三个微卫星标记紧密连锁(v1f148, v145f120, v95f166), 图距分别为6.6, 8.6 和8.6cM, 相应LOD值分别为17.8 14.3 和 16.4。 与雌性图相对应的是,雄性图谱未发现任何与性别连锁的标记。推测凡纳滨对虾的性别决定机制可能是ZW型,其中雌性为异配性别。 体长和体重均显示出连续变异的特点,显示这些与生长相关的性状都是典型的数量性状或多基因遗传。体重和体长符合正态分布且两性状之间存在着显著的相关性(P<0.001),Pearson 相关系数为0.95。在凡纳滨对虾雌性图谱和雄性图谱上,共定位了6个与体长和体重等生长性状相关的QTL,可解释的表型变异从15.1%到21.3%。共检测到3个与体长相关的QTL,包括两个正向效应的QTL和一个负向的QTL,分别定位到雌性的第6连锁群和雄性的第4和11 连锁群上。体重也检测到3个QTL,其中一个QTL加性效应是正向的,分别位于雌性的第6和7连锁群及雄性的第11连锁群上。QTL主要集中在雌性图谱的Fc6和Fc7及雄性图的Mc4和Mc11上。体长和体重的QTL定位结果中各有两个是十分相似的,其相邻的标记位点完全一样,只是相应的LOD值略有差异,还各存在两性状特异的一个QTL。大多QTL与相邻标记之间的距离只有0.1cM(仅Wfc7的距离较大),为进一步的精细定位奠定了基础。 分子标记筛选、遗传图谱的构建及生长相关性状的QTL定位为我们下一步从事分子标记辅助选择育种,QTL精细定位和比较基因作图打下基础,并最终推动凡纳滨对虾的遗传改良。
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Prescott, S. (2003). Women, Authorship and Literary Culture, 1690 - 1740. Basingstoke: Palgrave Macmillan. RAE2008
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http://books.google.com/books?vid=OCLC05766993
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BACKGROUND: Conflicting results have been reported among studies of protease inhibitor (PI) use during pregnancy and preterm birth. Uncontrolled confounding by indication may explain some of the differences among studies. METHODS: In total, 777 human immunodeficiency virus (HIV)-infected pregnant women in a prospective cohort who were not receiving antiretroviral (ARV) treatment at conception were studied. Births <37 weeks gestation were reviewed, and deliveries due to spontaneous labor and/or rupture of membranes were identified. Risk of preterm birth and low birth weight (<2500 g) were evaluated by using multivariable logistic regression. RESULTS: Of the study population, 558 (72%) received combination ARV with PI during pregnancy, and a total of 130 preterm births were observed. In adjusted analyses, combination ARV with PI was not significantly associated with spontaneous preterm birth, compared to ARV without PI (odds ratio [OR], 1.22; 95% confidence interval [CI], 0.70-2.12). Sensitivity analyses that included women who received ARV prior to pregnancy also did not identify a significant association (OR, 1.34; 95% CI, 0.84-2.16). Low birth weight results were similar. CONCLUSIONS: No evidence of an association between use of combination ARV with PI during pregnancy and preterm birth was found. Our study supports current guidelines that promote consideration of combination ARV for all HIV-infected pregnant women.
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At the FASEB summer research conference on "Arf Family GTPases", held in Il Ciocco, Italy in June, 2007, it became evident to researchers that our understanding of the family of Arf GTPase activating proteins (ArfGAPs) has grown exponentially in recent years. A common nomenclature for these genes and proteins will facilitate discovery of biological functions and possible connections to pathogenesis. Nearly 100 researchers were contacted to generate a consensus nomenclature for human ArfGAPs. This article describes the resulting consensus nomenclature and provides a brief description of each of the 10 subfamilies of 31 human genes encoding proteins containing the ArfGAP domain.
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In this article, the buildingEXODUS (V1.1) evacuation model is described and discussed and attempts at qualitative and quantitative model validation are presented. The data set used for the validation is the Tsukuba pavilion evacuation data. This data set is of particular interest as the evacuation was influenced by external conditions, namely inclement weather. As part of the validation exercise, the sensitivity of the buildingEXODUS predictions to a range of variables and conditions is examined, including: exit flow capacity, occupant response times, and the impact of external conditions on the developing evacuation. The buildingEXODUS evacuation model was found to produce good qualitative and quantitative agreement with the experimental data.