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In West Africa, rural livelihoods depending on natural resources develop coping and adapting strategies to face climate variability or change and economic or political changes. The former Lake Faguibine in northern Mali has experienced drastic ecological, social, and economic changes. Forests have emerged on the former lake and have become important for local livelihoods. This paper analyses the coping and adapting strategies of forest- and livestock-based livelihoods facing ecological changes. Results from field research at different levels indicate that most local strategies are based on diversification including migration within the livestock production system or in complement to it, with differences according to gender, age, and ethnicity. Political discourses, cultural identities, and past experiences influence and shape adaptation strategies at the local level. The sustainability of the observed strategies depends on the access to natural resources and the sustainable management of these resources, which in turn depends on institutions at local and national levels. Many local strategies are reactive to external events but would need strategic support from higher levels to move from coping to adapting. Examples are the development of institutions and technical actions for natural resource management, as well as development actions supporting local strategies and sustainable investments. Researchers, practitioners and development planners will need simple methods and tools for understanding and analysing local adaptation perceptions and actions to achieve an effective support of sustainable and gender-equitable local adaptation and to avoid mismatches between strategies proposed by local and by sub national and national actors.  相似文献   

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Nitrate and pesticide contamination of surface and groundwater has become a major problem in intensive farming regions in Europe, with nitrate concentrations reaching values above the standard defined in 2000 by the European Water Framework Directive. In the Seine basin, a major issue is the closure and abandonment of drinking-water wells, which force water managers and drinking-water producers to explore solutions for water resource protection. Organic farming has appeared as a credible alternative to conventional farming, and this study explores the potential of organic farming to reconcile agricultural production and water quality. On the basis of agricultural statistics, survey questionnaires and experimental data, the nitrogen soil surface balance (N-SSB) has been established at the scale of a small 104-km2 catchment (The Orgeval sub-basin), representative of the intensive cash crop farming in the Seine basin. The N-surplus for arable land in specialized organic cash crop systems has been found to be half that of current conventional systems (15 kg N ha−1 yr−1 versus 30 kg N ha−1 yr−1, respectively). The N-yield in organic systems is 21% lower than in conventional systems, but total fertilization (mostly symbiotic N fixation) is also 26% lower. Whereas 2–3 years of forage legume (e.g., alfalfa) as a starter crop of the typical 7- to 10-year diversified rotation builds up N soil fertility and helps prevent weeds without pesticides, the existence of an outlet for this fodder production is a limiting factor for the economic sustainability and the environmental benefits of these farming systems. Therefore, we explored the possibility of a reconnection of livestock and crop farming systems in the Orgeval catchment, a traditional dairy farming and Brie cheese production region. We calculated the N-SSB for this type of a reconnected livestock and cropping system and found a value very close to the specialized organic cash crop system with full utilization of fodder production, leading to profitable animal production, essentially as milk in this farm design. This reconnected system is compared with the estimated situation in 1955 before separation of plant and livestock production. Furthermore, the N-SSB values were converted into infiltrating sub-root concentrations and used as a boundary condition to a biogeochemical model. Organic cropping and organic reconnected livestock cropping systems result in a 50% reduction of surface water nitrate concentrations, a surface water quality 20% better than that reconstructed for 1955, with an overall higher protein production.  相似文献   

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‘Design for Remanufacture’ or DfRem, is an area of remanufacturing research that has received relatively high levels of interest in recent years, due to the recognition that a product’s design may have a high impact on remanufacturing efficiency. However, the overall volume of literature dedicated to DfRem is low and there is still much to learn about the subject. The purpose of this literature review is to collate the current body of literature and establish a contemporary understanding of DfRem through analysing the trends, agreements and conflicts of opinion in the field. Much of the DfRem literature to date is focused upon the investigation of remanufacturing problems associated with product design, and the subsequent development of design methods and tools, either specifically developed to aid DfRem or as adaptations of existing design methods. These methods and tools vary in purpose and intended use but all largely remain within the academic realm to date. Within the literature there is widespread agreement that any approach to DfRem must consider both product and process, yet the ‘design for X’ definition of the task continues to spark debate. The key problems and issues that future DfRem research should address have been identified in this paper, from both within the literature and from the current gaps in the literature. Some key recommendations for future research include the need for ‘lifecycle thinking’ within design method development and the need for greater exploration into the organisational factors affecting DfRem integration into the design process, from the perspectives of the OEM and designer.  相似文献   

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Nigeria is endowed with abundant energy resources, both conventional and renewable, whichprovide her with immense capacity to develop an effective national energy plan. However, introduction of renewable energyresources into the nation's energy mix have implications on itsenergy budget. The national energy supply system has been projected intothe future using MARKAL, a large scale linear optimization model.However, this model may not be absolutely representative of the highlynon-linear future of renewable energy. Results of the model reveal that under onlya least cost constraint, only large hydro power technology is the prominentcommercial renewable energy technology in the electricity supply mix of thecountry. Despite the immense solar energy potentials available, solar electricity generation is attractive only under severeCO2 emissions mitigation of the nation's energy supply system. Similarly, the penetration of small-scale hydro power technology in theelectricity supply mix is favoured only under CO2 emissionsconstraints. Due to economy of scale, large hydropower technology takes the lion share of all the commercial renewableenergy resources share for electricity generation under any CO2emissions constraint. These analyses reveal that some barriers exist to thedevelopment and penetration of renewable energy resources electricity production in Nigeria's energy supplysystem. Barriers and possible strategies to overcome them arediscussed. Intensive efforts and realistic approachtowards energy supply system in the country will have to be adopted inorder to adequately exploit renewable energy resources and technologiesfor economic growth and development.  相似文献   

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While the concepts of remanufacturing and reverse logistics are gaining popularity in practice, the available literature and theory on strategic decision making in these areas are limited. This paper is designed to address this gap, in particular, for the automotive industry aftermarket. In doing so, the authors reviewed literature pertaining to: customer demand(s), product design and development, cost-benefit analysis of reman, core (i.e., used product) supply management, reman competencies and skills, product life cycle strategies, reman and reverse logistics network design, relationships among key stakeholders, environmental considerations, regulations, and impact of emerging economies. The literature findings along with our experience in working with automotive reman products were used as inputs to guide the formulation of seven major propositions for the strategic factors in decision making within reman. The propositions were then tested through a case study. The case study reconfirmed many of the factors like product life cycle, regulations, etc. from the literature review and also identified new factors like OE customer requirements. Our results provide a foundation for further research for companies that deal with Original Equipment (OE) Sales, Original Equipment Service (OES), as well as Independent Aftermarket (IAM) business in the automotive industry.  相似文献   

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An analytical framework is developed in this paper in order to explore the diversity of eco-innovations according to several key dimensions (design, user, product service and governance). The framework is used to analyse a set of case studies of eco-innnovation processes. The diversity of the analysed eco-innovations appears to be considerable; each of them involves different kinds of combinations of elements pertaining to those dimensions. Albeit the design dimension is decisive to determine the environmental impacts of the innovation, all dimensions can play a significant role in the management of eco-innovation. Our findings suggest that the capacity of eco-innovations to provide new business opportunities and contribute to the transformation towards a sustainable society depends on the interplay of those dimensions and the engagement of key stakeholders in the innovation process.  相似文献   

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This paper frames the response by business to the challenge of sustainable development in terms of innovation. It addresses how the shift in business focus from competitiveness to sustainability impacts the capabilities and competence for innovation. A review of the literature suggests that innovation for sustainability requires the active involvement of a broader and more diverse network of actors, including those with more local knowledge of the implications of innovations than is the case with more conventional forms of innovation. The paper also identifies a systematic failure to address the need for inventiveness as a cornerstone of innovation. The paper puts forward elements of an applied research agenda to support the development of a better understanding of the capabilities that foster the competence by business to innovate in ways that are more sustainable.  相似文献   

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The width and other characteristics of the growth layers in trees provide valuable information on past variations in climate. Not only can past climate be deduced from past growth, but computers can be used to calibrate the tree growth with climate and to obtain quantitative estimates or reconstructions of the climatic variables in the past from the measurements of ring widths. Large arrays of many tree-ring chronologies exhibit large-scale spatial anomalies in growth. These anomalies can be converted by means of the calibration equations into large-scale reconstructions of spatial anomalies in climate. In this way a map is produced of climatic conditions for individual seasons within each year as far back in time as tree-ring data are available for the sites used for calibration. Some of the biological and physical phenomena that influence the climatic records are described, and the unique opportunities provided by tree-ring analysis of climate are summarized.  相似文献   

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应对气候变化已经成为全世界共同面对的重要议题 全球数千名科学家合作对温室气体排放与全球平均气温上升之间的关系做了许多模拟和情景预测.研究结果表明,如果按照目前能源利用趋势,2030年全球温室气体排放量将达402亿吨当量,几乎是1990年的两倍.这意味着大气中温室气体的浓度将超过1000 ppm(1ppm为百万分之一),全球气温将上升6摄氏度.6度升温,将导致大规模气候变化,给地球和人类带来难以承受和无法弥补的损害.  相似文献   

13.
The auditory thresholds of the AN2 interneuron and the behavioural thresholds of the anti-bat flight-steering responses that this cell evokes are less sensitive in female Pacific field crickets that live where bats have never existed (Moorea) compared with individuals subjected to intense levels of bat predation (Australia). In contrast, the sensitivity of the auditory interneuron, ON1 which participates in the processing of both social signals and bat calls, and the thresholds for flight orientation to a model of the calling song of male crickets show few differences between the two populations. Genetic analyses confirm that the two populations are significantly distinct, and we conclude that the absence of bats has caused partial regression in the nervous control of a defensive behaviour in this insect. This study represents the first examination of natural evolutionary regression in the neural basis of a behaviour along a selection gradient within a single species.  相似文献   

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The objective selection of biotechnological priority areas in accordance with global goals established by the government, which is undertaken jointly by science, industry and the government, poses some problems. In order to objectify decisions, therefore, a data recording system has been developed by way of example (for the field of biotechnology in Japan), which enables an analysis to be made of research activities to date as well as forecasts of the future development.  相似文献   

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目前,国内针对沙氏外硫红螺菌的研究鲜见报道。为了挖掘功能光合细菌新菌源,从茂名水东湾红树林潮间带泥样分离到1株能以硫化物作为电子供体营光合自养作用的紫色光合细菌HBL-1。根据菌株的形态、细胞色素光吸收特征及自动微生物鉴定系统检测的碳源利用结果,结合系统发育分析,鉴定该菌为沙氏外硫红螺菌(Ectothiorhodospira shaposhnikovii)。该菌培养条件粗放,尤其在偏碱性、含盐、光照微氧条件下生长最快;该菌能耐受较高浓度的Na_2S,在Na_2S初始浓度为227.6 mg/L时,培养6 d后,Na_2S转化率达到66.9%。结果表明该菌在水质净化方面显示较好的应用前景。  相似文献   

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The substitution of biogas, an energy source derived from biological feedstock, for fossil natural gas (NG) can mitigate the build-up of greenhouse gases in the atmosphere, making it an attractive renewable energy source in a carbon-constrained future. Although upgraded, pipeline-quality biogas can augment the NG market supply in the United States of America (USA), researchers and energy industry experts have little studied its long-term potential. This report estimates (1) levelized costs of energy for biogas production facilities operating with landfill waste, animal manure, wastewater sludge, and biomass residue feedstocks, (2) feedstock and technology pathway-specific biogas supply functions, and (3) the aggregate national biogas supply potential for the USA by 2040. Under a range of specified assumptions, generation of biogas could be expanded to approximately 3–5 % of the total domestic NG market at projected prices of $5–6/MMBtu, with the largest potential source coming from thermal gasification of agriculture and forest residues and biomass. As market signals have not spurred widespread adoption of biogas in the USA, policy incentives, similar to those used in the European Union (E.U.), may be necessary to increase its production and use. Bioenergy policy in the E.U. and the resulting market penetration achieved there therefore provides important lessons for how biogas markets in the USA can overcome barriers to market expansion and, in doing so, provide substantial climate mitigation benefits.  相似文献   

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Social capacity building for natural hazards is a topic increasingly gaining relevance not only for so-called developing countries but also for European welfare states which are continuously challenged by the social, economic and ecological impacts of natural hazards. Following an outline of recent governance changes with regard to natural hazards, we develop a heuristic model of social capacity building by taking into account a wide range of existing expertise from different fields of research. Particular attention is paid to social vulnerability and its assessment, as well as to risk communication and risk education as specific strategies of social capacity building. We propose to distinguish between interventionist and participatory approaches, thus enabling for a better understanding of existing practices of social capacity building as well as their particular strengths and weaknesses. By way of conclusion, we encourage more research on social capacity building for natural hazards in the European context which at present is highly diverse and, at least in parts, only poorly investigated.  相似文献   

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Transdisciplinary approaches are becoming increasingly adopted as a way to research complex socio-environmental problems. Conceptually, transdisciplinarity aims to foster meaningful knowledge co-production through integrative and participatory processes that bring together diverse actors, disciplines, and knowledge bases. In practice, transdisciplinarity is more ambiguous. While there is a growing body of literature on such approaches, there remains no widely-accepted definition, concrete framework, or empirical strategy for how to carry out a transdisciplinary project. We propose that this lack of explicit structure and entrenched meaning leaves space for transdisciplinary approaches to be shaped by the evolving network of participating scientists and stakeholders, according to their perspectives of the approach and what it embodies. Here, we examine the perspectives of a diverse group of actors (n = 42) embarking on a 10-year transdisciplinary research project focused on building resilience to natural hazards and disasters in New Zealand. We present the findings of qualitative surveys and group interviews that investigate stakeholders’ and scientists’ early perspectives of transdisciplinary, or co-created, research. The study represents the first stage of longitudinal research that will continue over the course of the project. Results show that early actors in the project share an overall consistent understanding of co-created research. Participants described a process that integrated diverse people and knowledge; created benefits on both a social and personal level; fostered clear, two-way dialogue; and overcame pragmatic and intrinsic challenges. Collectively, participants agreed with adopting transdisciplinary approaches to natural hazard, risk, and resilience research, with stakeholders showing a stronger degree of agreement than scientists. While attitudes towards transdisciplinarity were overall positive, a number of underlying conflicts emerged in regards to carrying out new modes of knowledge production within traditional social and institutional structures. These conflicts result in a tension that is felt by actors involved in transdisciplinary projects early on, and in some cases, influences perception of their ability to fully participate in such an approach. Evaluating actor perspectives and expectations early in the transdisciplinary process can give insight into how attitudes, expectations, and conflicts might shape transdisciplinary efforts, and can provide relevant parameters for assessing change over time.  相似文献   

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The recent and upcoming reforms of the Common Agricultural Policies (CAPs) aim at strengthening the multifunctional role of agriculture, acknowledging the differences in economic, environmental and social potentials within European regions. This paper presents results from an integrated assessment of existing and future policies within the framework set up in the FP6 EU project MEA-Scope. Spatial explicit procedures allow for the MEA-Scope modelling tools to provide information related to regional, environmental and socio-economics settings. The impact of different policy scenarios on structural change, land abandonment and cropping pattern of typical farms has been assessed based on linked agent-based (ABM) and Linear Programming (LP) models at regional and farm scale for two study areas. For the German case study area Ostprignitz-Ruppin (OPR), the issue of policy targeting has been addressed by relating non-commodity outputs (NCOs) to soil quality and protection status. For the Italian case study area (Mugello), changes in landscape patterns in terms of increased fragmentation or homogeneity as affected by changes in agricultural intensity have been analysed using semivariance analysis. The spatial explicit approach highlighted the relevance of case study research in order to identifying response structures and explaining policy implementation patterns.  相似文献   

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