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401.
有机氯类农药为已确定的环境雌激素,易在体内蓄积产生慢性毒性危害人体健康。选择单一存在时无明显雌激素效应的残留剂量进行联合试验,观察联合作用后雌激素效应的增减。选取乳腺癌MCF-7细胞作为研究对象,对残留剂量下六氯苯(HCB)、β-六六六(β-BHC)和p,p’-滴滴涕(p,p’-DDT)联合后的雌激素效应机制进行了研究。首先,运用MTT法观察3种有机氯类农药残留剂量下单独和联合作用对MCF-7细胞生长的影响;然后,运用流式细胞仪测定有机氯类农药联合对MCF-7细胞周期的影响;之后,采用Western Blot法测定有机氯类农药联合后ERα、ERβ、ERK1/2、p-ERK1/2、Ki67、c-Myc和Cyclin D1蛋白表达的变化。结果显示,β-BHC+p,p’-DDT组、HCB+β-BHC+p,p’-DDT组作用24 h后细胞增殖率为115.0%、120.1%,作用48 h后增殖率为121.2%、126.3%,其他联合组与对照相比未发生明显变化;β-BHC+p,p’-DDT组、HCB+β-BHC+p,p’-DDT组中MCF-7细胞的G1期细胞比例下降,S期细胞比例上升,细胞呈高增殖状态;β-BHC+p,p’-DDT组、HCB+β-BHC+p,p’-DDT组和雌二醇(E2)组作用48 h后,均降低ERα的蛋白表达,升高ERβ的蛋白表达,促进p-ERK1/2、Ki67、Cyclin D1和c-Myc的蛋白表达。研究表明,在单一作用时不具有雌激素效应的残留剂量下,仅β-BHC+p,p’-DDT联合组和HCB+β-BHC+p,p’-DDT联合组具有明显雌激素效应,其效应机制为经雌激素受体途径,激活ERβ蛋白表达,抑制ERα蛋白表达,促进p-ERK1/2、Ki67、c-Myc和Cyclin D1等相关蛋白的表达。  相似文献   
402.
Conservation Planning as a Transdisciplinary Process   总被引:1,自引:0,他引:1  
Abstract: Despite substantial growth in the field of conservation planning, the speed and success with which conservation plans are converted into conservation action remains limited. This gap between science and action extends beyond conservation planning into many other applied sciences and has been linked to complexity of current societal problems, compartmentalization of knowledge and management sectors, and limited collaboration between scientists and decision makers. Transdisciplinary approaches have been proposed as a possible way to address these challenges and to bridge the gap between science and action. These approaches move beyond the bridging of disciplines to an approach in which science becomes a social process resolving problems through the participation and mutual learning of stakeholders. We explored the principles of transdisciplinarity, in light of our experiences as conservation‐planning researchers working in South Africa, to better understand what is required to make conservation planning transdisciplinary and therefore more effective. Using the transdisciplinary hierarchy of knowledge (empirical, pragmatic, normative, and purposive), we found that conservation planning has succeeded in integrating many empirical disciplines into the pragmatic stakeholder‐engaged process of strategy development and implementation. Nevertheless, challenges remain in engagement of the social sciences and in understanding the social context of implementation. Farther up this knowledge hierarchy, at the normative and purposive levels, we found that a lack of integrated land‐use planning and policies (normative) and the dominant effect of national values (purposive) that prioritize growth and development limit the effectiveness and relevance of conservation plans. The transdisciplinary hierarchy of knowledge highlighted that we need to move beyond bridging the empirical and pragmatic disciplines into the complex normative world of laws, policies, and planning and become engaged in the purposive processes of decision making, behavior change, and value transfer. Although there are indications of progress in this direction, working at the normative and purposive levels requires time, leadership, resources, skills that are absent in conservation training and practice, and new forms of recognition in systems of scientific reward and funding.  相似文献   
403.
Two disciplines claim to provide justification of action. Ethics gives you moral reasons to act upon, whereas economics exploits the concept of rationality. The paper discusses two theories of interdisciplinarity of ethics and economics in order to clarify the relationship. The traditional view of a hierarchical ordering of ethics and economics is rejected, and it is claimed that there are substantial economic contributions to ethical justification.  相似文献   
404.
Wang X  Sun C  Gao S  Wang L  Shuokui H 《Chemosphere》2001,44(8):1711-1721
Germination rate and root elongation, as a rapid phytotoxicity test method, possess several advantages, such as sensitivity, simplicity, low cost and suitability for unstable chemicals or samples. These advantages made them suitable for developing a large-scale phytotoxicity database and especially applicable for developing quantitative structure–activity relationship (QSAR) to study mechanisms of phytotoxicity. In this paper, the comparative inhibition of germination rate and root elongation of Cucumis sativus by selected halogen-substituted phenols and anilines were determined. The suitability of germination rate and root elongation as phytotoxicity endpoints was evaluated. Excellent reproducibility and stability of germination rate and root elongation in the control test, relatively greater sensitivity and similar dose–response relations for all tested compounds were observed. These results together with those of a 2-day test were used to demonstrate the suitability of this phytotoxicity test method. A QSAR was developed for the phytotoxicity mode of action of the tested compounds to C. sativus seeds. Models that combined the logarithm of 1-octanol/water partition coefficient (log Kow) and the energy of the lowest unoccupied molecular orbital (Elumo) were developed for both germination rate inhibition and root elongation inhibition. The results of these studies indicate that phytotoxicity of substituted phenols and anilines to C. sativus seeds could be explained by a polar narcosis mechanism. This paper will promote the application of germination rate and root elongation method and the development of large-scale phytotoxicity database, which will provide the fundamental data for QSAR and ecological risk assessment of organic pollutants.  相似文献   
405.
中国目前存在着大量的环境犯罪行为,但对环境犯罪的追究力度不够。许多国家将违反环保部门决定的行为直接规定为犯罪,这种做法体现了环境刑法的行政从属性特征,有利于对环境犯罪行为的判断,可以强化环保部门的环境保护作用,对环境保护起到预防作用。中国应借鉴这些做法,在立法上加以明确的规定,并重视相关问题的研究。  相似文献   
406.
生态文明意识是建设社会主义生态文明的源动力和前提条件。以山东省聊城市为例,对8个县市区的20个社会主义新农村试点村和19个对照村进行了生态文明意识调查。调查内容包括生态文明认知度、农民环保态度、生态文明行为现状及生态文明建设的评价与期望四个部分。调查结果表明,与全省平均水平相比,聊城市社会主义新农村试点村申农民生态文明认知度有所提高,对照村处于较低水平。村民个体的社会主义新农村建设中的生态文明意识仍有待进一步提高。  相似文献   
407.
汶川8.0级地震具有突发性强,破坏性巨大,影响范围广,继发灾害多等特点,造成了重大人员伤亡和财产损失。这次地震对我国现有的地震应急后勤保障工作是一次全面的检查和考验。根据军队在地震灾时后勤保障遇到的问题,提出了完善物资储备机制,夯实后勤保障的物质基础;完善交通运输机制,提高后勤物资输送能力的方针。针对医院后勤保障在灾时遇到通讯保障能力不足、信息报送滞后、医疗环境差、医疗设备陈旧、物资储备不足等问题,也给出了相应的处置对策和方法。  相似文献   
408.
Coping with ambiguities in natural resources management has become unavoidable. Ambiguity is a distinct type of uncertainty that results from the simultaneous presence of multiple valid, and sometimes conflicting, ways of framing a problem. As such, it reflects discrepancies in meanings and interpretations. Under the presence of ambiguity it is not clear what problem is to be solved, who should be involved in the decision processes or what is an appropriate course of action. Despite the extensive literature about methodologies and tools to deal with uncertainty, not much has been said about how to handle ambiguities. In this paper, we discuss the notions of framing and ambiguity, and we identify five broad strategies to handle it: rational problem solving, persuasion, dialogical learning, negotiation and opposition. We compare these approaches in terms of their assumptions, mechanisms and outcomes and illustrate each approach with a number of concrete methods.  相似文献   
409.
In biodiversity hotspots, there is often tension between human needs and conservation, exacerbated when protected areas prevent access to natural resources. Forest-dependent people may compensate for exclusion by managing unprotected forests or cultivating planted woodlots. Outside Bwindi Impenetrable National Park in Uganda, household wood product needs are high and population growth puts pressure on the environment. We investigated the role of privately and collectively managed woodlots in provisioning wood products and supporting local livelihoods. We found that households relied heavily on woodlots for daily needs and as resources during time of need. We also found that locally relevant social institutions, called stretcher groups, played a role in the management of woodlots, providing shared community resources. Privately and collectively owned woodlots support local livelihoods and wood product needs in the region. Long-term management of forests in Uganda should consider the value of woodlots and the mechanisms required to support them.  相似文献   
410.
Millions of people worldwide are involved in artisanal and small-scale gold mining. Many of them live in conditions of poverty and insalubrities due to the mercury amalgamation of gold and the application of other rudimentary techniques. In spite of this, the sector has been nearly overlooked by resource economists. In this paper we analyze the sector based on a survey of the existing literature. We find some commonalities of artisanal and small-scale gold mining in different countries of the developing world as follows: low levels of mechanization and technology, labor intensiveness, low awareness of environmental degradation, poor training, high transience among some miners, and lack of financial savings. Moreover, with these commonalities in mind, we present some topics and challenges for a research agenda in the field of environmental, ecological, and development economics.  相似文献   
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