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染色体免疫共沉淀测序(Chromatin immunoprecipitation followed by sequencing,ChIP-seq)是研究DNA-蛋白质互作的有力工具,被广泛用于RNA聚合酶、转录因子和组蛋白修饰等在基因组上的精确定位。近年来,在ChIP-seq技术的基础上,科学家提出了一系列研究DNA-蛋白质互作的技术方法,提高了测序分辨率,降低了实验成本,极大推动了表观基因组学的发展。本文综述了多种DNA-蛋白质互作研究技术的原理及其应用场景,介绍了在单细胞水平上研究DNA-蛋白质互作的实现方法,并展望其未来发展的方向。 相似文献
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中国对虾人工越冬和卵巢催熟正交实验报告 总被引：2，自引：1，他引：2
海水的温盐度、pH值、溶解氧、氨氮含量,光照以及饵料质量、病原体感染和环境惊扰等,都可能是直接或间接影响对虾越冬存活率和卵巢发育的因子。通过研究其中有些因子的作用,初步取得了一些结果,而有些尚需要进行较深入的探讨。 实验以中国对虾(penaeus orientalis Kishinouyel)为材料进行了多因子正交探讨,所得结果为确定对虾越冬最佳工艺条件提供科学依据。 相似文献
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栉孔扇贝大量死亡的流行病学调查研究 总被引：1，自引：0，他引：1
2001~2003年,对养殖的栉孔扇贝进行了较系统地流行病学调查研究.以栉孔扇贝养殖集中海区长岛县亚美扇贝养殖场为定点调查和样品采集点.调查内容主要包括栉孔扇贝各养殖期的死亡率和可疑病原生物检测,同时对pH、溶解氧、温度、盐度等环境理化因子进行连续监测.调查结果显示:栉孔扇贝在养殖初期幼贝阶段死亡率较低,随后死亡率逐渐升高,至8月24日月死亡率达最高点71%.9月份以后死亡率开始下降.至10月份累积死亡率达90%以上.对环境理化因子的调查显示,pH、溶解氧、盐度的变化幅度不大,与扇贝死亡率无明显相关性;温度变化与死亡率似有一定的相关性,即高温(月平均23℃以上)可能是养殖栉孔扇贝重要的环境胁迫因子.通过对可疑致病性生物因子的调查研究及病理学观察表明,栉孔扇贝在养殖过程中可感染多种微生物,其中原核微生物类立克次体(RLO)在养殖过程各生长阶段均可检出,其感染率和感染强度与扇贝死亡率呈现一致的趋势.在病原病理检测中,发现RLO的大量感染与组织细胞严重病理损伤密切相关.在病原生物检测过程中,除RLO以外还发现有类枝原体原核生物(MLO)和类病毒(VLP)寄生.RLO的人工感染实验结果说明RLO是栉孔扇贝重要的病原菌.结合感染率和死亡率、感染强度和组织病理学的相关性以及感染实验的结果分析,认为类立克次体(RLO)可能是栉孔扇贝养殖过程中大量死亡的主要致病因子. 相似文献
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鱼类体液免疫研究进展 总被引：24，自引：0，他引：24
同其他的脊椎动物一样 ,鱼类的免疫系统包括体液免疫和细胞免疫。鱼类的体液免疫系统还包括非特异性免疫 (主要由体液因子参与 )和特异性免疫 (主要由抗体分子参与 )两个部分。本文就近阶段鱼类体液免疫方面的重要进展作一综述。１鱼类的非特异性体液免疫鱼类的非特异性体液免疫的主要作用物质是血液或黏液中的体液因子 ,这些体液因子主要针对病原感染的早期阶段 ,是鱼类抵抗病原感染的第一防线。鱼类主要的非特异性体液因子有以下几种。１ .１溶菌酶溶菌酶是存在于许多鱼类的体表黏液、肠道黏液、血清和巨噬细胞中的一种水解酶。实验证明 ,… 相似文献
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NR1D1和NR1D2转录因子属于核受体转录因子家族，二者通过调控靶基因表达参与众多生物学过程，尤其在昼夜节律调节中发挥重要作用。本研究通过分析NR1D1和NR1D2的蛋白质分子特征以及在冷胁迫下珍珠龙胆石斑鱼(Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂)的基因调控关系以及它们所参与的通路，揭示它们在鱼类低温环境中的功能作用。生物信息学比较分析显示〖STBX〗NR1D1和NR1D2〖ST〗基因序列均有23个开放阅读框，编码的蛋白质均属于不稳定的亲水性蛋白质。NR1D1和NR1D2蛋白质均含有ZF C4类锌脂蛋白结构域和Hormone_Recep核激素受体的配体结合域，主要配体为含铁原卟啉IX。这两种蛋白主要在细胞核中发挥调控基因表达的作用，且与昼夜节律通路的多个关键基因有直接作用关系。结果表明，在冷胁迫下NR1D1和NR1D2作为转录因子可通过调控靶基因的表达，参与昼夜节律调节并促进糖脂代谢、线粒体氧化等过程，为珍珠龙胆石斑鱼提供必要的能量，有助于增强其耐寒性。 相似文献
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目的：探讨糖尿病患者体质、炎症因子白细胞介素-6（IL-6）、C反应蛋白（CRP）水平与足溃疡预后的关系，为糖尿病足溃疡（DFU）的防治提供新思路。方法：收集71例住院的DFU患者，采用《中医体质分类与判定》评定患者体质，测定炎症因子IL-6、CRP水平及伤口情况（wagner分级、感染程度）。观察不同体质DFU患者伤口愈合时间（是否超过4周）。分析主要体质的代谢指标、伤口情况及炎症因子IL-6、CRP水平。结果：血瘀质和湿热质是DFU难愈伤口的常见体质，痰湿质伤口相对易愈。3种体质伤口wagner分级比较无统计学差异（P＞0.05），感染程度比较有统计学差异（P<0.05）。血瘀质、湿热质难愈伤口感染程度较痰湿质易愈伤口重，炎症因子IL-6、CRP水平均比痰湿质易愈伤口高。血清IL-6、CRP与伤口愈合成负相关（P>0.05），与感染程度成正相关（P<0.05），踝肱指数与感染程度成负相关（P<0.01）。结论：血瘀质、湿热质糖尿病患者伤口较难愈合，其伤口愈合困难可能与易感染、机体氧化应激加重等因素导致炎症因子水平升高有关。 相似文献
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Svein Jentoft Ratana Chuenpagdee Jose J. Pascual-Fernandez 《Ocean & Coastal Management》2011,54(1):75-83
Marine Protected Areas (MPAs) are established for various purposes. Some are aimed at protection, some are intended as resource management tools, while others imply both of these objectives, as well as others. Regardless of the stated goals, the same MPA can mean different things to different people, and these meanings may be inconsistent. In practice, MPA goals are not always stated clearly, and even if they are, they do not necessary align well with what the different actors have in mind. Moreover, the stated goals are not always those that govern the actual operation of MPAs. The priorities of goals may also change over time for stakeholders and for MPAs. In this paper we argue that the goals of MPAs should not be assumed a priori but should be researched empirically. Thus, before we can answer why MPAs succeed or fail in reaching their goals, we must ask what these goals are in the first place and how they came into existence. How are they, for instance, established, negotiated and agreed upon among stakeholders? How do they reflect particular interests, perspectives and power differentials of those involved? Here, we provide a framework for how to analyze the formation, complexity, and displacement of goals in MPAs, presenting three case studies as illustration. 相似文献
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《Oceanic Engineering, IEEE Journal of》2009,34(3):250-261
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《Marine Policy》2016
This article presents a framework for fisheries sector analysis based on the literatures on global value chains (GVCs) and global production networks (GPNs). A value chain approach offers an alternative to focusing primarily on policy as an explanatory variable, by bringing into focus relations among buyers, sellers and other stakeholders as well as their institutional context. After outlining the utility of this approach, the article identifies three questions at the forefront of contemporary debates on the dynamics of GVCs and GPNs. Namely: (1) How institutional context affects distributional and regulatory outcomes; (2) The conditions under which particular institutions that limit or regulate market forces are either productive or perverse; and (3) Why and how particular markets are constituted in the ways that they are. The article then showcases some of the central findings from the case studies brought together in this thematic issue, demonstrating how they contribute to current analytic debates surrounding value chains and core substantive problems facing both fisheries and those engaged in the fishing industry. 相似文献
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In recent years many fuller ship hull forms have been designed and constructed in various shipbuilding countries, but the data available for the development of the fuller forms are inadequate from the point of view of preliminary ship design. In this paper the authors describe how they have systematically tested vessel forms of block coefficients ranging from 0.80 to 0.90. The analysis and presentation of the test results have been made in such a manner that designers can produce hull forms like those of tankers and other bulk carriers quickly and reliably. 相似文献
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《Oceanic Engineering, IEEE Journal of》2005,30(3):588-600
This paper describes a novel framework for classifying underwater transient signals recorded by passive sonar. The proposed approach involves two key ideas. Firstly, a feature-selection algorithm is used to identify those acoustic features that optimally model each class of transient sound. Secondly, features that are perceptually motivated are proposed, i.e., they encode information that human listeners are likely to use in transient classification tasks. Three perceptual features are proposed, which encode timbre, the physical material of the sound source, and the temporal context (pattern) in which the transient occurred. The authors show how these features, which are computed over different temporal windows, can be combined to make classification decisions. The performance of the proposed classifier is evaluated on a corpus of transient signals extracted from passive sonar recordings. Specifically, the performance of the perceptual features is compared with spectral features and with those that encode statistics of time, frequency, and power. The present results show that the perceptual features provide valuable cues to the class of a transient. However, the best performing classifier was obtained by selecting a subset of perceptual, spectral, and statistical features in a class-dependent manner. 相似文献
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《Marine Policy》2017
The purpose of this paper is to analyse the relationship of the proposed new UNCLOS Implementing Agreement concerning the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction with the current legal framework concerning fisheries. It elaborates on selected elements that are under negotiations, namely: marine genetic resources, area-based management tools, including marine protected areas, as well as environmental impact assessments. Each of those elements is analyzed with particular emphasis being laid on the following issues. Firstly, how the current legal status quo in the relevant area looks like. Secondly, how the question of fisheries could be included in a future treaty and, thirdly, what bearing it could have on the current framework of the management of fisheries.The article concludes with the identification of possible fields where the new treaty could bring added value. However, some possible challenges are mentioned as well. They relate in particular to the fact that the mandate of negotiations underscores that they shall not ‘undermine existing legal instruments and frameworks and relevant global, regional and sectoral bodies’. 相似文献
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Most fisheries management studies have concentrated on understanding resource dynamics and have paid less attention to understanding the dynamics of those who use the resources. This situation limits the knowledge about the fisheries system as a whole and specifically about the viability of management schemes. It is vital to understand how the actors within the fishing sector (fishing firm owners/managers, fishers, fisheries managers, and traders) may respond to changes in fishing resources trends, market dynamics, and fisheries policies before they are implemented. These issues are explored in this paper by applying a longitudinal analysis of the Yucatan Mexico's fishing industry. The analysis is presented within the framework of the theory of change and coping strategies. The study primarily involved interviews during 2008 with the main owners of companies in the fishing industry and with fisheries managers and other stakeholders. Time-series catch data on the main fishing resources are also reviewed to evaluate changes across three historical periods and describe how the actors have perceived and responded to those changes. Given conditions of uncertainty in resource availability, changes in market demand and changes in institutional arrangements, the viability of traditional business and resource management practices are discussed. The analysis presents different kind of triggers that have modified the conditions of the fishing sector and had had impacts on the socio-economic–ecological system in which fisheries are embedded. The need for adaptive strategies in the whole chain of the fisheries business and resource management is stressed, given the current changes and conditions of fisheries. The discussion states a series of actions that could improve the relationships between business practices and fisheries management. 相似文献
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The diffusive regime of double-diffusive convection 总被引：2，自引：0，他引：2
D. E. Kelley H. J. S. Fernando A. E. Gargett J. Tanny E.
zsoy 《Progress in Oceanography》2003,56(3-4):461
The diffusive regime of double-diffusive convection is discussed, with a particular focus on unresolved issues that are holding up the development of large-scale parameterizations. Some of these issues, such as interfacial transports and layer-interface interactions, may be studied in isolation. Laboratory work should help with these. However, we must also face more difficult matters that relate to oceanic phenomena that are not represented easily in the laboratory. These lie beneath some fundamental questions about how double-diffusive structures are formed in the ocean, and how they evolve in the competitive ocean environment. 相似文献
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《Marine Policy》2001,25(5):365-376
This paper explores the nature of conflict and how institutional failure may be a primary cause of conflict over natural resources. Typologies for studying conflicts are reviewed and a typology specific to tropical fishery conflicts is proposed. Using data from three tropical fisheries, it shows how conflicts emerge and how they are managed.1 The paper concludes that local level management of conflict can be successful, but, without proactive support from higher levels of government the underlying causes of conflict are unlikely to be removed in the long term. 相似文献