牙鲆(Paralichthys olivaceus)β诺达病毒衣壳蛋白重组表达及复性条件优化 组表达及复性条件优化

β诺达病毒利用其缺乏校正功能的聚合酶进行基因组复制, 易导致突变, 因而具有广泛的宿主感染性, 而且可引发致死率极高的病毒性神经坏死症, 需要有针对性地研究检测及防御方法。本研究以感染牙鲆(Paralichthys olivaceus)的β诺达病毒为对象, 利用引物设计, 将His标签编码序列连接到完整病毒衣壳蛋白C端, 构建原核表达载体; 采用SDS-PAGE及质谱对表达产物进行分离和鉴定; 重组衣壳蛋白经镍离子亲和柱纯化后进行复性条件的正交优化。结果表明4个肽段经质谱鉴 定与预期一致; 纯化产物产量可达36mg/L; 4°C条件下, 复性缓冲液中尿素和PBS的最适浓度为0.8mol/L和0.05mol/L。本研究建立的制备方案可为研制相关疫苗以及开发针对该病毒的快速检测产品等提供有价值的参考。     

Volunteered geographic information research in the first decade: a narrative review of selected journal articles in GIScience

ABSTRACT

More than 10 years have passed since the coining of the term volunteered geographic information (VGI) in 2007. This article presents the results of a review of the literature concerning VGI. A total of 346 articles published in 24 international refereed journals in GIScience between 2007 and 2017 have been reviewed. The review has uncovered varying levels of popularity of VGI research over space and time, and varying interests in various sources of VGI (e.g. OpenStreetMap) and VGI-related terms (e.g. user-generated content) that point to the multi-perspective nature of VGI. Content-wise, using latent Dirichlet allocation (LDA), this study has extracted 50 specific research topics pertinent to VGI. The 50 topics have been subsequently clustered into 13 intermediate topics and three overarching themes to allow a hierarchical topic review. The overarching VGI research themes include (1) VGI contributions and contributors, (2) main fields applying VGI, and (3) conceptions and envisions. The review of the articles under the three themes has revealed the progress and the points that demand attention regarding the individual topics. This article also discusses the areas that the existing research has not yet adequately explored and proposes an agenda for potential future research endeavors.     

黏弹性与弹性介质中Rayleigh面波特性对比研究

Rayleigh面波的频散特性可以用来研究地表浅层结构. 本文使用时域有限差分法来模拟复杂黏弹性介质中的Rayleigh面波,研究了Q值对面波频散特性的影响.文中采用旋转交错网格有限差分,以非分裂卷积形式的完全匹配层为吸收边界,推出了求解二阶位移-应力各向同性黏弹性波动方程的数值方法.为了检验数值解的精度,首先将简单模型的正演结果与解析解对比,验证了方法的正确性;然后模拟了横向缓变层状介质和含有洞穴的介质中的面波,对弹性和黏弹性介质中的面波的频散特性进行对比分析.模拟结果表明浅层Q值对面波的频散特性有显著的影响;强吸收情况下,高阶面波的能量相对低阶面波能量显著增强.     

The Influence of the “Mixed Pixel” Problem on the Detection of Analogous Forest Communities Between Presettlement and Present in Western New York∗

We conducted a land change analysis to determine if the forest communities of presettlement and present contain areas that are analogous in composition, using surveys of the Holland Land Company (1797–1799) and U.S. Forest Service (1991–1993) from western New York. Gridded forest-type maps are produced from each survey using two models: a uniform model that assumes each data grid cell is occupied by a single forest type, and a mixture model in which grid cells are assumed to be occupied by multiple forest types in different proportions. The mixture model consistently detects a larger area of analogous communities in the two time periods at both global and local scales.     

欧盟减排《责任分担条例》修正案分析与启示

欧盟自1997年起就如何通过市场和行政手段“双轮驱动”控制碳排放总量进行不断探索,并逐步建立了较为成熟的碳排放交易体系及减排责任分担机制,已经取得了良好的减排效果。文中梳理分析《责任分担条例》修正案中关于成员国减排目标更新的内容、目标分配的原则与方法、灵活性机制,归纳了欧盟采用行政手段控制碳排放交易系统未涉及部门的温室气体排放的经验,并对中国如何构建充分考虑市场手段和行政手段的CO₂排放总量控制制度提出政策建议。     

GIScience research challenges for emergency management in Southeast Asia

Natural Hazards - The study examines the current application of geospatial information technologies and highlights the challenges of and constraints on GIScience research for emergency management...     

Exploratory Spatiotemporal Analysis in Risk Communication during the MERS Outbreak in South Korea

The 2015 Middle East respiratory syndrome (MERS) outbreak in South Korea gave rise to chaos caused by psychological anxiety, and it has been assumed that people shared rumors about hospital lists through social media. Sharing rumors is a common form of public perception and risk communication among individuals during an outbreak. Social media analysis offers an important window into the spatiotemporal patterns of public perception and risk communication about disease outbreaks. Such processes of socially mediated risk communication are a process of meme diffusion. This article aims to investigate the role of social media meme diffusion and its spatiotemporal patterns in public perception and risk communication. To do so, we applied analytical methods including the daily number of tweets for metropolitan cities and geovisualization with the weighted mean centers. The spatiotemporal patterns shown by Twitter users' interests in specific places, triggered by real space events, demonstrate the spatial interactions among places in public perception and risk communication. Public perception and risk communication about places are relevant to both social networks and spatial proximity to where Twitter users live and are interpreted in reference to both Zipf's law and Tobler's law.     

钙激活钾通道在中华绒螯蟹(Eriocheir sinensis) 血淋巴细胞免疫中的作用研究

采用膜片钳技术解析了中华绒螯蟹血淋巴细胞表达的大电导钙激活钾通道(BKca),研究了中华绒螯蟹BKca对血淋巴细胞吞噬和杀菌作用的影响,并探讨了其机制.结果表明,当Ca2+浓度在0.3-3.0μmol/L范围时,中华绒螯蟹血淋巴细胞表达的钙激活钾通道的开放表现出明显的钙依赖活性;培养液中游离Ca2+的添加显著增强了血淋巴细胞的杀菌能力和呼吸爆发活性,但对其吞噬率和吞噬指数的影响不显著;在6mmol/L[Ca2+]浓度条件下,加入不同浓度的Kca阻断剂四乙胺(Tetraethylammonium,TEA)后,血淋巴细胞的杀菌能力和呼吸爆发活性均显著降低,但其吞噬率和吞噬指数并未受到影响.这提示钙激活钾通道可能通过间接调节细胞内的钙离子浓度而在血淋巴细胞杀菌过程中发挥重要作用.     

Semi-automatic shallow landslide detection by the integration of airborne imagery and laser scanning data

Landslide mapping is essential for effective watershed management. In Taiwan, a typhoon or earthquake event can trigger hundreds, even thousands, of shallow landslides in mountainous watersheds. Thus, improving the efficiency of landslide mapping by means of remote sensing techniques is an important issue. This study proposes a new method that uses concurrent aerial laser scanning (ALS) data and color ortho-imagery as input data: the topographic indices of slope, surface roughness, and object height model can be derived from the ALS data and the Green–Red Vegetation Index from the ortho-images. The method first uses these topographic and spectral indices in a global, semi-automatic algorithm to separate landslide from non-landslide pixels. It then offers a region growing tool and a 3D Eraser/Painter to edit detected landslides locally. These global and local operations are designed with a user interface, which is intuitive and user-friendly. Results from four test sites in a mountainous watershed prove that the method is easy, accurate, and suitable for landslide mapping in Taiwan.