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Previous analyses of the debate on the assisted colonization of species (AC) omit a critical assessment of the rhetorical dimension of the AC debate. To address this gap, we ask: what kinds of arguments are deployed as mean of persuasion and what are the implications of the rhetorical dimension of the AC debate for decision-making on AC? Our methods consist of textual network analysis, which allowed us to generate maps of the arguments in the debate on AC and analyze these maps using standard network analytical measures. The argument maps of the AC debate emphasize different and multi-faceted value judgments. Some of these are couched in technical terms and thus are implicitly evaluative: what is an appropriate level of risk for focal species and recipient communities, how much knowledge/ignorance is sufficient to warrant action or inaction, and what species or ecosystem services are most valuable and should be prioritized in conservation science and management? Other types of arguments, however, are more explicitly evaluative: socio-economic calculations, defending or criticizing conventional principles of conservation policy, and ethical norms and values. While some of the technical aspects of the debate may be resolved by more research, the controversy over AC is unlikely to be resolved by science alone, because the issue is thoroughly enmeshed in rhetoric about who should have control over AC governance.  相似文献   

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This paper addresses the interactions between the AIDS epidemic and climate change in southern Africa, particularly as they impact on food security. An assessment was undertaken through a comprehensive literature review. Understanding the underlying causes of regional food insecurity inevitably means understanding the role of the AIDS epidemic and increasingly climate change amongst other stressors. AIDS cuts through household and community level capacity, as well as the capacity of key facilitators of the adaptation process including state extension services and civil society organisations. The main argument of the paper is that adaptation to climate change must explicitly factor in the existing and long-term effects of the epidemic. While calls for embracing adaptation abound, little is being done to assess and strengthen the organisational capacity of institutions, which should play leading roles in any attempt to help prepare for a changing climate. In particular the capacity of key agencies has been undermined by the AIDS epidemic. This reiterates the need for a multisectoral approach and building bridges between agriculture and health sectors to ensure longer term support to livelihoods where HIV and hunger coexist, often overlaid by climate change.  相似文献   

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Consumer demand for environmentally and socially responsible products is the driving force behind the expansion of competing certification systems. Paradoxically, this has led to an increasingly crowded marketplace for labels and confusion among stakeholders such as producers, retailers and buyers, rather than providing clear and reliable product information as intended. The situation has sparked a debate about the future of certification schemes and the need for a more streamlined system. This article explores some of the innovative ideas coming from the current discussion regarding biofuel certification and standardisation and outlines how those ideas can be applied to create a global generic standard-setting scheme for natural resources.  相似文献   

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The question whether the possibility exists of transmission of HIV by hematophagous insects from infected to uninfected persons is a point of very intensive discussion. The solution of this problem could help to explain the spreading of the disease in human populations and could contribute to an understanding of the evolution of AIDS and the possible transfer from wild primates into human populations. The classical routes of pathogen transmission by blood-sucking arthropods are either "mechanical" or "biological". Both ways are rejected, the latter since no replication of the retro-virus in the vector exists and its survival in the arthropod is very limited. Based on long experimental experience with biting flies as well as with plant-sucking insects a third hitherto neglected way of transmission by regurgitation of gut content can be introduced. Since regurgitation is neither "mechanical" nor "biological", "regurgitative transmission" must be introduced as an additional term.  相似文献   

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通过添加膨润土和玻璃粉调节垃圾焚烧飞灰中Ca/Si比例的方法,研究了飞灰陶粒的形成条件,结果发现添加10%的玻璃粉,于1 000℃下煅烧30 min可以得到筒压强度为6.5 MPa,单颗粒强度为315N的陶粒,满足轻集料相对应堆密度的强度标准,并且降低了成本。进一步明确了飞灰高温煅烧后冷却形成玻璃体的形成条件:烧结温度需高于飞灰熔融温度50℃左右,并且以空气骤冷作为冷却方式。  相似文献   

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进入新世纪以来,我国艾滋病防治社会工作及其能力建设奠定了坚实的理论与实务基础,但也面临一系列的挑战,而构建核心能力体系是我国艾滋病防治社会工作发展的必然趋势。基于能力结构的价值—知识—技术三维模型,艾滋病防治社会工作核心能力不仅包括尊重接纳和预防为本、优势视角和增能参与、结构干预和整体关怀的价值理念,而且包括预防医学和传染病学、艾滋病易感过程和机制、艾滋病防治政策与社会福利的理论知识,还包括健康促进与健康教育、危机介入与同伴教育、哀伤辅导与临终关怀以及个案管理与社会倡导的实务技术等。基于新冠疫情防控的中国探索与经验启示,未来需要通过不断的制度化、学科化、专业化与标准化来促进艾滋病防治社会工作的能力建设与人才发展,切实提升社会工作服务于艾滋病防治的社会成效。  相似文献   

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Endemic South American river stingrays (Potamotrygonidae), which include the most diversified living freshwater chondrichthyans, were conspicuously absent from pre-Neogene deposits in South America despite the fact that recent phylogenetic analyses strongly suggest an older origination for this clade. To date, the rare representatives of this family were mostly represented by ambiguous isolated remains. Here, we report 67 isolated fossil teeth of a new obligate freshwater dasyatoid (Potamotrygon ucayalensis nov. sp) from the fossiliferous level CTA-27 (Yahuarango Formation), near Contamana, in the Peruvian Amazonia. We assigned this sample to a new representative of Potamotrygon by comparison with numerous fresh jaws of living specimens of Potamotrygonidae, thus providing the first detailed review of dental morphology for this poorly understood clade. These new fossils fill a long stratigraphic gap by extending the family range down to the middle Eocene (~41 Mya). Moreover, the relative modernity and diversity in tooth morphology among Eocene freshwater stingrays (including Potamotrygon ucayalensis nov. sp. and coeval North American dasyatoids) indicate that the hypothetically marine ancestor of potamotrygonids probably invaded the rivers earlier than in the middle Eocene. The first potamotrygonids and affiliates were possibly more generalized and less endemic than now, which is consistent with an opportunistic filling of vacated ecospace.  相似文献   

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城市的记忆--工业废弃地更新、改造浅析   总被引:4,自引:0,他引:4  
针对在城市发展中出现的工业废弃地的问题,文章立足于城市的更新、改造,结合当今国内外城市工业废弃地更新、改造的实践,从城市历史文化的角度,对工业废弃地的更新、改造的理论和方法在宏观和微观两个层面进行了分析和探讨.  相似文献   

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气象条件对可吸入颗粒物浓度的影响   总被引:3,自引:0,他引:3  
气象条件对可吸入颗粒物浓度有较大的影响,通过对鞍山市二年来的监测数据进行分析,得出了结论并提出建议.  相似文献   

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事故性泄漏的有毒气体的风险性评价   总被引:3,自引:0,他引:3  
针对有毒气体发生事故性泄漏时具有瞬间性的特点,选取适宜的烟团扩散模式,在多种气象条件下,对有毒气体地面浓度的分布状况进行了预测研究.结果表明:有毒气体有害浓度分布区域与泄漏发生后、事故发生时的气象条件有关.  相似文献   

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按照生态学原理建立的循环经济模式,克服了传统经济模式下环境污染和生态破坏无法有效解决的问题,是一种可持续发展模式.为从根本解决环境污染问题,循环经济观念越来越被理解和接受,并被广泛应用.  相似文献   

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GB/T7490-1987规定的水质挥发酚测定方法,在实际工作中监测结果往往出现较大的误差,影响了监测结果的准确性.对于这种误差本文主要从pH值、4-氨基安替比林、反应溶液显色时间等方面进行分析,探讨满足监测结果准确性和精密性的适宜条件和技术要求.  相似文献   

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序批式活性污泥法工艺MATLAB仿真模型的初步建立   总被引:3,自引:0,他引:3  
序批式活性污泥法工艺(SBR)是目前应用很广的一种污水处理工艺,本文在国际水协会(IWA)的ASM1模型的基础上,建立了SBR工艺反应模型,通过模型检验可发现,该模型能较好地模拟SBR工艺反应中的微生物处理过程,具有很大的发展前景。  相似文献   

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清洁生产是控制环境污染的有效途径   总被引:1,自引:0,他引:1  
末端治理在防治污染过程中起一定作用,取得了一定的成绩,但实践证明,末端治理模式在不同方面存在明显不足,不能有效防治污染,清洁生产的引入,使环保史上发生一场革命,清洁生产是一种全程的污染防治,即经济又有效,要全面推广还存在一定的困难,需各部门共同努力.  相似文献   

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改革开放后,我国进入了城市化迅速发展的阶段.城市化促进了经济的发展,同时也带来了许多问题.耕地大量被占用,耕地面积迅速减少.但与此同时,我国有关耕地方面的立法尚不完善.因此,本文将就进一步保护耕地,完善土地管理立法进行的初步探讨.  相似文献   

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壳聚糖水果保鲜膜的应用探讨   总被引:5,自引:0,他引:5  
研究以壳聚糖为主料制备壳聚糖膜的方法,用这些膜分别在常温和低温(3℃)条件下进行水果保鲜.对不同封膜体系的失水率、二氧化碳含量变化、总酸和总糖变化量进行定量测试和对比,结果表明复合金属离子的壳聚糖膜的保鲜效果要优于纯壳聚糖膜、日本保鲜膜和普通PVC膜,其中,复合锌离子的壳聚糖膜的保鲜效果最好.本文对壳聚糖膜的保鲜机理进行了初步的探讨.实验表明,复合金属离子的壳聚糖膜是一种既可保鲜又可为人体补充微量元素的绿色可食水果保鲜膜.  相似文献   

20.
主要介绍了以苯为吸收液的紫外分光光度测定的一种新的方法.该方法操作较为简单,测定数据较为精确,符合郎伯比尔定律,并且重现性好,变化不明显,适用于大气或车间空气的测定.  相似文献   

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