Late Neogene rock magnetic record of climatic variation from Chinese eolian sediments related to uplift of the Tibetan Plateau

IEECAS SKLLQG

长白山地区红松树干呼吸的研究

采用土壤呼吸气室于2003年5～10月测定了长白山阔叶红松林主要树种红松不同径阶不同方位的树干呼吸,同时监测了树干温度和林内温度.结果表明,树干呼吸速率具有明显的季节变化趋势,呈单峰曲线,8月出现最大值,2月呼吸速率最低.树干呼吸速率与树干温度具有显著幂指数关系,同时表现出大径阶树干呼吸速率与温度因子间曲线拟合效果好于小径阶红松.不同径阶树干呼吸速率均呈南面高于北面,并随树干径阶的减小南北面呼吸速率差异降低.不同径阶红松树干平均维持呼吸占总树干呼吸6363%,红松树干径阶越大维持呼吸所占比例越大.依树干径阶大小顺序分别为6676%、7329%和5084%.不同径阶红松树干呼吸Q10值在256～332之间,利用呼吸Q10值分别获得不同径阶树干Rt和Rm的季节变化趋势.因此,当估算生态系统呼吸时应考虑树干不同部位和不同径阶之间的差异.

三工河流域新老绿洲发育度的比较

绿洲是干旱区最重要的景观单元之一。人工绿洲是在干旱条件下经长期人类活动改造而形成的特殊景观。随着人类对绿洲水土资源开发利用程度的不断加强,绿洲呈现出不同的发展阶段。从天然绿洲到人工绿洲,是人类适应和改造干旱区自然环境的历程。在这一人地相互作用的过程中,绿洲显示出明显的发育演化特征。从多学科综合的角度,提出绿洲发育度的概念,并从灌溉体系的建设状况、水资源的利用水平、植被与生态建设、农业发展程度、社会经济水平和绿洲景观结构等7个方面提出了绿洲发育度的评价指标体系,以天山北坡2个人工绿洲为例,从空间上定量比较2个绿洲的发育程度,其中阜康市绿洲发育度高于222团绿洲(阜北农场)。

杀伤血管内皮生长因子受体1阳性细胞的靶向毒素

白喉毒素(diphtheria toxin DT) 是棒状白喉杆菌被茁噬菌体感染后分泌的一种外毒素. 它可以阻断真核细胞的蛋白质合成,杀死细胞. 血管内皮生长因子(VEGF) 的R82A,K84A,H86A突变体可以和肿瘤血管上高表达的VEGF受体1 (VEGFR-1) 特异性结合. 首先从白喉杆菌中提取基因组DNA,扩增出白喉毒素C区、T区基因. 并运用点突变技术,制成VEGF的R82A,K84A,H86A突变体. 利用这个可以和肿瘤血管上特异性受体相结合的VEGF的突变体,代替白喉毒素上的受体结合区,制成了针对VEGFR-1的靶向融合毒素——DT391-mVEGF. 以去除了受体结合区的DT391为阴性对照,细胞实验表明,融合毒素对VEGFR-1阳性的肿瘤细胞有特异性杀伤作用.

树木、林内、林冠上与森林区风速廓线研究(英文)

风速是森林生态系统研究中最为重要的变量之一,同时也是控制气流运输过程最基本的要素。由于树木生理指标和生长过程对风速的改变十分敏感,因此风速随高度的变化规律,即风速廓线的研究十分重要。一般认为,在裸地或林冠上的风廓线均呈对数规律变化,但是在单株树木和林分内风速随高度的变化则不呈对数规律。本文根据最近在海岸松林内风的研究结果,总结了针叶树种单株树木内、林分内和林冠上层以及海岸林区的风速廓线变化规律,其主要结论如下:1)单株针叶树树冠内的风速廓线呈指数形式分布,2)在林分内的风速廓线可用风的减弱系数来表示,3)[(\267\347)(\300\252\317\337\324\332\301\326\271\332\262\343)]上的分布可由风廓线参数(摩擦速度、粗糙长度、零平面位移)确定,4)在海岸林区,极端风速的分布可以使用了建筑上的风荷载模型进行预测。另外,本文提出了该研究领域尚需进一步探讨的问题,主要包括:1)风速廓线与树木特征及林分特征间的关系,2)利用简单的方法预测了风速廓线参数,3)风速廓线在树木生理、生态研究的作用、树木生长过程中风的微生态学效应以及森林生态和管理应用等方面。图4表1参60。

樟子松人工固沙林稳定性的研究

提出了人工林稳定性的内涵及其评价标准．分析了影响沙地樟子松人工林稳定性的各种干扰因子，通过对沙地樟子松人工林造林成活、生长情况、对不良外界环境的抗御能力、林分寿命、林分结构和生产力的综合评价分析，认为沙地樟子松引种人工林基本上是稳定的；而生长在立地较好的丘间低地的林分，其稳定性大于沙丘顶部的林分；从抗枯梢病角度看，幼林的抗性大于中林；从林分密度和生产力角度来看．红花尔基沙地樟子松林稳定性高于章古台．

72型分光光度计的改装

为满足多元素分析的需要,对一台72型分光光度计进行了改装,增加了数显、打印等功能.本文介绍改装后的光学系统、信号放大电路、数显和打印电路.改装后的仪器,测量速度比原来提高约10倍,可作批量样品的连续测定.

牙鲆生长相关性状遗传力估计

遗传力是数量遗传学的重要参数，对鱼类良种选育具有重要意义。可靠的遗传力估计值可以为合理制定育种计划提供宝贵信息，同时可以预测选择反应。本文按照10×3因子设计方法，10尾雄鱼与3尾雌鱼两两授精，产生10个父系半同胞、3个母系半同胞及30个全同胞家系，以微卫星分子标记为家系鉴定手段，对40日龄牙鲆生长相关性状遗传力进行了估计；同时，初步探讨了因子交配设计及人工控制条件下，亲本对子代遗传贡献率差异及有效群体大小。主要结论包括：1.初步筛选的14个微卫星位点中，有9个（Po91、Po1、Po56、Po20、Poli23、Po89、Poli121、Po42、Po13）在亲本中呈现中、高度多态性：平均等位基因9.4个；平均亲本特异性等位基因4个。用5个位点（Po91、Po1、Po56、Po20、Poli23）为346个子代中的227个个体找到所属家系；继续用另外4个位点（Po89、Poli121、Po42、Po13）分型，成功鉴定72个个体。鉴定率约86%，其中，亲本特异性等位基因的存在使鉴定效率大大提高。以上9个位点可为该群体良种选育工作提供技术支持。2. 发生降解的DNA与完整的DNA，在相同引物、相同PCR体系、相同模板浓度下扩增的带型一致。该结果证实了微卫星分型对降解的DNA同样稳定。3. 亲本对子代的遗传贡献率存在差异。雄亲的贡献率为5.8—14.3%，除3号、9号子代数较少，5号、6号子代数较多外，其它父本基本一致；母本对子代的贡献率差异较大（18.5%—50.6%），这与人工授精前雌亲发育状况、卵子质量检测结果基本一致，在一定程度上说明，母本尤其是卵子质量对鱼类早期存活具有较大影响。4. 家系内子代数目的不平衡导致实际有效群体大小下降。Ne=7.44，比理论有效群体大小（9.23）下降约19%。但与自然交配相比（有效群体下降可达75%），人工控制下的交配在一定程度上可有效限制遗传多样性的下降。5. 基于父本方差组分，40日龄生长相关性状遗传力估计值（h2s±S.E.）为（0.157±0.052）－（0.440±0.137）。加性遗传方差在表型方差中所占的比例，在一定程度上表明该牙鲆群体生长性状具有一定的选择力度。

Centenarians and their hearts: a prospective registry with comprehensive geriatric assessment, electrocardiogram, echocardiography, and follow-up

Background Data on the cardiac characteristics of centenarians are scarce. Our aim was to describe electrocardiogram (ECG) and echocardiography in a cohort of centenarians and to correlate them with clinical data. Methods We used prospective multicenter registry of 118 centenarians (28 men) with a mean age of 101.5 ± 1.7 years. Electrocardiogram was performed in 103 subjects (87.3%) and echocardiography in 100 (84.7%). All subjects underwent a follow-up for at least 6 months. Results Centenarians with abnormal ECG were less frequently females (72% vs 93%), had higher rates of previous consumption of tobacco (14% vs 0) and alcohol (24% vs 12%), and scored lower in the perception of health status (6.8 ± 2.0 vs 8.3 ± 6.8). Centenarians with significant abnormalities in echocardiography were less frequently able to walk 6 m (33% vs 54%). Atrial fibrillation/flutter was found in 27 subjects (26%). Mean left ventricular (LV) ejection fraction was 60.0 ± 10.5%. Moderate or severe aortic valve stenosis was found in 16%, mitral valve regurgitation in 15%, and aortic valve regurgitation in 13%. Diastolic dysfunction was assessed in 79 subjects and was present in 55 (69.6%). Katz index and LV dilation were independently associated with the ability to walk 6 m. Age, Charlson and Katz indexes, and the presence of significant abnormalities in echocardiography were associated with mortality. Conclusions Centenarians have frequent ECG alterations and abnormalities in echocardiography. More than one fifth has atrial fibrillation, and most have diastolic dysfunction. Left ventricular dilation was associated with the ability to walk 6 m. Significant abnormalities in echocardiography were associated with mortality.

Xanthoria parietina as a biomonitor of airborne heavy metal pollution in forest sites in the North East of Morocco

Xanthoria parietina, common foliose lichen, growing in its natural habitat, was analysed for the concentration of five heavy metals (Fe, Cr, Zn, Pb and Cu) from different forest sites of North East of Morocco (Kenitra, Sidi Boughaba, Mkhinza, Ceinture Verte near Temara city, Skhirate, Bouznika and Mohammedia). The quantification was carried out by inductively coupled plasma - atomic emission spectrometry (ICP-AES). Results were highly significant p<0,001. The concentration of metals is correlated with the vehicular activity and urbanization. The total metal concentration is highest at the Kenitra area, followed by Ceinture Verte site near Temara city, which experience heavy traffic throughout the year. Scanning electron microscopy (SEM) of particulate matter on lichen of Xanthoria parietina was assessed as a complementary technique to wet chemical analysis for source apportionment of airborne contaminant. Analysis revealed high level of Cu, Cr, Zn and Pb in samples near roads.  

The causes and consequences of Rent-seeking in Northern Ireland, 1945-72

Northern Ireland's economic performance during the 'golden age' was weak. Crafts suggested that rent-seeking was an important determinant of this poor record. This article offers support for such a conclusion. It is suggested that the growth record was shaped by British regulations preventing conflicts of ministerial interest not being made operational until 1963. This institutional divergence tended to promote rent-seeking behaviour, which impeded the pursuit of an industrial policy that could promote economic efficiency. In 1963 the institutional structure and the industrial policy framework changed. These changes stimulated the pursuit of efficiency and contributed to an improved regional economic performance.