Methods to analyze cell type-specific gene expression profiles from heterogeneous cell populations

Recent technical progress in DNA and protein identification has made genome-wide survey of gene expression at tissue and animal levels a routine approach, such as microarray and RNA sequencing technologies to measure mRNA abundance and mass spectrometry to measure protein abundance. A key limitation in applying these genome-wide gene expression profiling methods at tissue and animal levels is that the contribution of a specific cell type to the total amount of measured gene expression cannot be determined. Here, we review currently available approaches to resolve this and discuss future directions of study to solve questions not addressable by state-of-the-art techniques.     

广西滨海区域景观格局分析及土地利用变化预测

研究滨海湿地景观动态及其发展趋势对于维持沿海地区可持续发展具有重要意义。利用移动窗口法分析广西滨海湿地景观格局时空变化,同时提取珍珠湾、茅尾海和丹兜海典型区进一步分析景观变化趋势,最后采用土地利用变化模型(Land Change Modeler,LCM)预测区域未来的景观演化趋势。结果表明,2000—2014年间,草地、乔木园地和常绿阔叶灌木林面积减少,而工业用地面积明显增加。研究区总体的景观异质性变化不大,破碎化趋势不明显。比较景观格局指数发现,边缘密度和多样性指数的空间分布特征相似,多样性指数较大的区域,边缘密度也大,并且多集中于珍珠湾、茅尾海和研究区的中东部。3个典型区的格局变化趋势相似,景观多样性指数降低而均匀度增加,其中,湿地斑块数目减少且所占面积比也减少。LCM模型结果表明,至2020年,草本湿地与森林灌丛湿地面积进一步降低,而工业用地和居民区则持续增长;其中,3个典型区土地利用变化均受到了工业发展的影响,以珍珠湾土地利用动态度最高,茅尾海其次,而丹兜海最小。当前,区域景观的变化明显降低了湿地植被的质量,加强湿地植被保护,限制工业区域的无序发展是维持区域生境完整和安全的有效途径。     

激光捕获显微切割技术在植物基因组研究中的应用

植物的生长和发育在很大程度上取决于组织和(或)器官特异表达的基因, 但要获取某一发育阶段的特异细胞类群来进行基因表达分析又是相当困难的。近年发展起来的激光捕获显微切割技术可以在显微镜下快速准确地获取单一的细胞类群, 甚至单个细胞, 成功地解决了组织中细胞的异质性问题。介绍了该技术的原理, 并对其在植物中的应用进展情况做了综述, 同时指出了该技术在植物中应用的可能发展方向。     

Helias A. Udo De Haes: A Practical Scientist

Goal, Scope and Background The importance of the social dimension of sustainable development increased significantly during the last decade of the twentieth century. Industry has subsequently experienced a shift in stakeholder pressures from environmental to social-related concerns, where new developments in the form of projects and technologies are undertaken. However, the measurement of social impacts and the calculation of suitable indicators are less well developed compared to environmental indicators in order to assess the potential liabilities associated with undertaken projects and technologies. The aim of this paper is to propose a Social Impact Indicator (SII) calculation procedure based on a previously introduced Life Cycle Impact Assessment (LCIA) calculation procedure for environmental Resource Impact Indicators (RIIs), and to demonstrate the practicability of the SII procedure in the context of the process industry in South Africa. Methods A framework of social sustainability criteria has been introduced for the South African process industry. The social sub-criteria of the framework are further analyzed, based on project and technology management expertise in the South African process industry, to determine whether the criteria should be addressed at project or technology management level or whether they should rather form part of an overall corporate governance policy for new projects and technologies. Furthermore, the proposed indicators for criteria that are considered appropriate for project or technology evaluation purposes are constrained by the type of information that is available, i.e. the calculation methodology relies on the availability of regional or national social information where the project will be implemented, as well as the availability of project- or technology-specific social information during the various phases of the project or technology development life cycle. Case studies in the process industry and statistical information for South Africa are subsequently used to establish information availability for the SII calculation procedure, demonstrate the SII method together with the RII method, and determine the practical use of the SII method. Results and Conclusion The case studies establish that social footprint information as well as project- and technology social data are not readily available in the South African process industry. Consequently, the number of mid-point categories that can be evaluated are minimal, which results in an impaired social picture when compared to the environmental dimension. It is concluded that a quantitative social impact assessment method cannot be applied for project and technology life cycle management purposes in industry at present. Recommendation and Perspective Following the outcomes of the case studies in the South African process industry, it is recommended that checklists and guidelines be used during project and technology life cycle management practices. Similar to the environmental dimension, it is envisaged that such checklists and guidelines would improve the availability of quantitative data in time, and would therefore make the SII procedure more practical in the future.     

淋巴细胞脉络丛脑膜炎病毒感染实验动物的情况概述

淋巴细胞脉络丛脑膜炎病毒（lymphocytic chorimeningtis virus,LCMV）能广泛感染啮齿类动物和人,是一种重要的人畜共患病病原。近些年LCMV感染人的检测得到加强,在实验动物中的感染率一直控制在较低水平。我国的实验动物国家标准要求豚鼠、地鼠必需检测LCMV,小鼠只在必要时检测,而国外普遍要求对大鼠等动物也作为常规检测项目。为了提高对实验动物感染LCMV的检测意识,本文对不同国家和地区LCMV感染实验动物的情况做一综述。     

Complexity untwined: The structure and function of cucumber (Cucumis sativus L.) shoot phloem

Cucurbit phloem is complex, with large sieve tubes on both sides of the xylem (bicollateral phloem), and extrafascicular elements that form an intricate web linking the rest of the vasculature. Little is known of the physical interconnections between these networks or their functional specialization, largely because the extrafascicular phloem strands branch and turn at irregular angles. Here, export in the phloem from specific regions of the lamina of cucumber (Cucumis sativus L.) was mapped using carboxyfluorescein and ¹⁴C as mobile tracers. We also mapped vascular architecture by conventional microscopy and X-ray computed tomography using optimized whole-tissue staining procedures. Differential gene expression in the internal (IP) and external phloem (EP) was analyzed by laser-capture microdissection followed by RNA-sequencing. The vascular bundles of the lamina form a nexus at the petiole junction, emerging in a predictable pattern, each bundle conducting photoassimilate from a specific region of the blade. The vascular bundles of the stem interconnect at the node, facilitating lateral transport around the stem. Elements of the extrafascicular phloem traverse the stem and petiole obliquely, joining the IP and EP of adjacent bundles. Using pairwise comparisons and weighted gene coexpression network analysis, we found differences in gene expression patterns between the petiole and stem and between IP and EP, and we identified hub genes of tissue-specific modules. Genes related to transport were expressed primarily in the EP while those involved in cell differentiation and development as well as amino acid transport and metabolism were expressed mainly in the IP.