Spatio-temporal variations of vegetation cover in northern Shaanxi Province under the background of ecological restoration

Based on the 2000-2008 MODIS-NDVI images and using dimidiate pixel model, a dynamic evaluation was made on the vegetation coverage in northern Shaanxi Province, one of the ecologically fragile area in China, under the backgrounds of returning farmland to forestland and grassland and of the integrated management of soil and water loss. In 2000-2008, the vegetation coverage in the study area fluctuated within a year, being the highest in August and the lowest in March, and showed an increasing trend from the northwest to the southeast. The annual maximum vegetation coverage had a pronounced increase, but the area of medium and high coverage increased while that of low coverage decreased. The increased area of vegetation coverage occupied more than half of the study area, especially in the northeast. Climate features and human activities were the main causes inducing the pronounced increase of vegetation coverage, reflecting to a certain extent the effectiveness of ecological restoration efforts. The dimidiate pixel model based on the MODIS-NDVI images could well and truly simulate the spatiotemporal variation trend of the vegetation cover in northern Shaanxi, and be applicable to quantitatively estimate and evaluate the effectiveness of vegetation restoration at regional scale.     

Reactive oxygen species generation and mitochondrial dysfunction in the apoptotic response to Bortezomib,a novel proteasome inhibitor,in human H460 non-small cell lung cancer cells

Bortezomib, a proteasome inhibitor, shows substantial anti-tumor activity in a variety of tumor cell lines, is in phase I, II, and III clinical trials and has recently been approved for the treatment of patients with multiple myeloma. The sequence of events leading to apoptosis following proteasome inhibition by bortezomib is unclear. Bortezomib effects on components of the mitochondrial apoptotic pathway were examined: generation of reactive oxygen species (ROS), alteration in the mitochondrial membrane potential (Delta psi m), and release of cytochrome c from mitochondria. With human H460 lung cancer cells, bortezomib exposure at 0.1 microM showed induction of apoptotic cell death starting at 24 h, with increasing effects after 48-72 h of treatment. After 3-6 h, an elevation in ROS generation, an increase in Delta psi m, and the release of cytochrome c into the cytosol, were observed in a time-dependent manner. Co-incubation with rotenone and antimycin A, inhibitors of mitochondrial electron transport chain complexes I and III, or with cyclosporine A, an inhibitor of mitochondrial permeability transition pore, resulted in inhibition of bortezomib-induced ROS generation, increase in Delta psi m, and cytochrome c release. Tiron, an antioxidant agent, blocked the bortezomib-induced ROS production, Delta psi m increase, and cytochrome c release. Tiron treatment also protected against the bortezomib-induced PARP protein cleavage and cell death. Benzyloxycarbonyl-VAD-fluoromethyl ketone, an inhibitor of pan-caspase, did not alter the bortezomib-induced ROS generation and increase in Delta psi m, although it prevented bortezomib-induced poly(ADP-ribose) polymerase cleavage and apoptotic death. In PC-3 prostate carcinoma cells (with overexpression of Bcl-2), a reduction of bortezomib-induced ROS generation, Delta psi m increase was correlated with cellular resistance to bortezomib and the attenuation of drug-induced apoptosis. The transient transfection of wild type p53 in p53 null H358 cells caused stimulation of the bortezomib-induced apoptosis but failed to enhance ROS generation and Delta psi m increase. Thus ROS generation plays a critical role in the initiation of the bortezomib-induced apoptotic cascade by mediation of the disruption of Delta psi m and the release of cytochrome c from mitochondria.     

植物雌激素三羟异黄酮抑制麻醉大鼠颈动脉窦压力感受器反射

采用隔离灌流麻醉雄性大鼠颈动脉窦技术,观察了植物雌激素三羟异黄酮（genistein,GST）对颈动脉窦压力感受器反射的影响。其结果如下:（1）以GST（50μmol/L）隔离灌流颈动脉窦区时,压力感受器机能曲线向右上方移位,曲线最大斜率（peak slope,PS）由0.36±0.01降至0.23±0.01（P<0.001）;反射性血压下降幅度（reflex decrease,RD）由39.75±1.58降至27.00±0.60 mmHg（P<0.001）,阈压（TP）和饱和压（SP）分别从65.63±2.10和192.23±3.90升至82.05±1.95mmHg（P<0.001）和215.76±3.75mmHg（P<0.001）。其中RD、PS和TP呈明显的剂量依赖性;（2）用Ca2+通道激动剂Bay K 8644（500 nmol/L）预处理后,能取消GST（50 μmol/L）对压力感受器反射的抑制作用;（3）预先灌流NO合酶阻断剂（L-NAME,100μmol/L）,不能阻断GST（50μmol/L）对压力感受器反射的抑制效应。以上结果提示,GST可能通过阻断Ca2+通道途径而抑制大鼠颈动脉窦压力感受器反射,并非由血管内皮细胞释放NO所致。     

Characterization of genome-wide long terminal repeat retrotransposons provide insights into trait evolution of four grapevine species

Grapevine is one of the most economically important crops in the world. Although long terminal repeat (LTR) retrotransposons are thought to have played an important role in plants, its distribution in grapevine is not clear. Here, we identified genome-wide intact LTR retrotransposons in a total of six high-quality grapevine genomes from Vitis vinifera L., Vitis sylvestris C.C. Gmel., Vitis riparia Michx. and Vitis amurensis Rupr. with an average of 2938 per genome. Among them, the Copia superfamily (particularly for Ale) is a major component of the LTR retrotransposon in grapevine. Insertion time and copy number analysis revealed that the expansion of 70% LTR retrotransposons concentrating on approximately 2.5 Ma was able to drive genome size variation. Phylogenetic tree and syntenic analyses showed that most LTR retrotransposons in these genomes formed and evolved after species divergence. Furthermore, the function and expression of genes inserted by LTR retrotransposons in V. vinifera (Pinot noir) and V. riparia were explored. The length and expression of genes related to starch metabolism and quinone synthesis pathway in Pinot noir and environmental adaptation pathway in V. riparia were significantly affected by LTR retrotransposon insertion. The results improve the understanding of LTR retrotransposons in grapevine genomes and provide insights for its potential contribution to grapevine trait evolution.     

BioSeq-BLM: a platform for analyzing DNA,RNA and protein sequences based on biological language models

In order to uncover the meanings of ‘book of life’, 155 different biological language models (BLMs) for DNA, RNA and protein sequence analysis are discussed in this study, which are able to extract the linguistic properties of ‘book of life’. We also extend the BLMs into a system called BioSeq-BLM for automatically representing and analyzing the sequence data. Experimental results show that the predictors generated by BioSeq-BLM achieve comparable or even obviously better performance than the exiting state-of-the-art predictors published in literatures, indicating that BioSeq-BLM will provide new approaches for biological sequence analysis based on natural language processing technologies, and contribute to the development of this very important field. In order to help the readers to use BioSeq-BLM for their own experiments, the corresponding web server and stand-alone package are established and released, which can be freely accessed at http://bliulab.net/BioSeq-BLM/.     

Early Intervention of Gastrodin Improved Motor Learning in Diabetic Rats Through Ameliorating Vascular Dysfunction

Neurochemical Research - The mechanism of cognitive dysfunction in diabetes is still unclear. Recently, studies have shown that the cerebellum is involved in cognition. Furthermore,...     

景观生态学中的格局分析：现状、困境与未来

作为景观格局分析的重要手段,景观格局指数的提出与发展极大地推动了景观生态学的发展,但是由于众多景观格局指数在指示生态学过程方面的不足,近年来景观格局分析已经走入困境。在总结近年来国内外相关研究的基础上,对景观格局分析的现状、困境及未来发展方向进行了综述。景观格局分析仍然是景观生态学的重要方面,景观格局指数仍然是景观格局分析的主要手段。但是如何建立具有生态学意义的景观格局指数和分析方法,如何将景观格局与生态过程联系起来,以及如何将＂基质—斑块—廊道＂的景观生态学理论应用到实际中是目前景观格局分析面临的主要困境。基于对景观格局分析现状及困境的认识,提出了景观格局分析未来的5个发展方向：（1）景观格局分析应该从目前的静态格局描述发展到对动态格局的刻画,只有找到刻画动态格局的方法,才能将格局和过程有机地联系在一起;（2）通过对多种景观格局指数的联合应用,发掘景观格局指数集合体对生态过程的解释能力;（3）发展基于生态过程的景观格局指数和分析方法;（4）通过多维景观格局分析,定量研究景观格局演变与生态过程之间的关系;（5）多尺度景观格局分析,将为解决格局与过程的关系提出有效手段。     

基于旅游从业者的卧龙自然保护区旅游发展有效性分析:社区参与视角

以卧龙自然保护区为例,采用问卷调查的方法对旅游从业者的来源地、收入分布和职业分布特征进行了研究,以综合分析旅游发展与生物多样性保护、经济发展以及保护区管理之间的关系及面临的问题,探讨旅游发展的有效性。结果表明,尽管旅游发展对当地经济有一定的贡献,但尚存如下问题需要解决：（1）旅游与当地居民经济参与和生物多样性保护之间关系比较微弱;（2）经济漏损和收入分配不平衡;（3）当地居民进入旅游业受到启动资金及技术技能条件的限制。     

基于mtDNA COⅠ和Cytb基因序列对南中国海不同海域波纹唇鱼群体遗传多样性的研究

研究以海南陵水、马来西亚、西沙、南沙4个海域共101尾波纹唇鱼作为研究对象, 通过线粒体DNA的COⅠ和Cytb基因序列分析方法对波纹唇鱼进行了遗传多样性研究。经PCR扩增、克隆与序列测定, 分别获得1560 bp COⅠ基因和1141 bp Cytb基因序列。两者多态性遗传参数统计显示, 101尾个体分别存在23 (COⅠ)和30 (Cytb)个变异位点, 分别检测出20 (COⅠ)和27 (Cytb)个单倍型, 总群体单倍型多样性(Hd)分别为0.629 (COⅠ)和0.755 (Cytb), 平均核苷酸差异数(K)分别为1.195 (COⅠ)和1.424 (Cytb), 核苷酸多样性指数(Pi)分别为0.00077 (COⅠ)和0.00126 (Cytb)。分子方差分析(AMOVA)结果分别为26.26% (COⅠ)和4.22% (Cytb)的变异来自群体间, 73.74% (COⅠ)和95.78% (Cytb)的变异来自群体内。同时, 两个基因的单倍型网络图呈星状放射结构, 不同地理来源的单倍型无明显分支, 呈交错分布, 没有体现地理差异性。研究初步认为, 波纹唇鱼的遗传多样性处于较低水平, 遗传分化存在但不显著, 该结果可为今后波纹唇鱼的种质资源保护工作提供必要的科学依据。       

县域人类活动与景观格局分析

人类活动的长期持续作用会导致区域景观格局及景观生态功能的变化 ,反过来又会对人类的生存质量和可持续发展能力构成影响。因此人类活动与景观格局的关系及其调控一直是景观生态学研究的重要内容。以植被图、土地利用图和林相图为基础 ,应用 GIS技术和景观格局分析方法研究了岷江流域汶川县人类活动与景观格局特征及其相互关系。结果表明 :通过重要植被类型的分析 ,可以明确不同类型在各乡镇单元的优势程度及其生态完整性 ;基于不同主题图件的景观格局指数之间相关特征的相似性显著 ;3种图件在反映景观破碎化程度上具有相似的能力 ,而在反映景观异质性方面存在显著差异 ;景观的边界密度确实能够由景观中的人类活动要素 (道路密度、居民点及工矿面积比例和农田面积比例 )之间一定的组合关系进行较好的表达与解释。这也充分说明 ,通过人类活动要素可以在一定精度范围内预测景观的变化趋势 ;同时 ,对人类活动的合理调控与管理有助于生态恢复和景观安全格局的维持。因此 ,对县域土地利用、生物多样性保护和区域发展的规划和管理具有重要的参考价值。