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French and European incentives, such as Plan Ecophyto 2018, European directive for a sustainable use of pesticides, reinforce the requirement for vine-growers to engage in more environmentally friendly farming practices. In this respect, this paper presenting the results of a large questionnaire survey conducted in Bordeaux area vineyards and focusing on the behaviour of their vine-growers towards environmental innovations is particularly adequate. Founding that the most important environmental issue in vineyards relates to the use of pesticides, the paper characterizes the main economic and cognitive factors determining vine-growers' environmental innovations. It allows determining possible policies milestones, efficient and feasible, towards a more environmentally friendly vineyard. The paper first outlines the analytical framework, then highlights the main results and, finally, goes through further discussion and policy implications.  相似文献   
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The genetic parentage and pedigrees of 35 litters from 12 family groups of monogamous Alpine marmot (Marmota marmota) in the French Alps were analyzed using six hypervariable sequence repeat nuclear loci (microsatellites). All of the members of these family groups were sampled during a 5-year period. Hairs taken directly from animals served as a source of DNA for amplification of the loci. Our results indicate that the genetic mating system of the Alpine marmot is quite different from a strictly monogamous breeding system. Extra-pair paternity occurred in 11 of the 35 litters (31.4%). Of the 134 juveniles typed, 26 (19.4%) could be attributed to extra-pair copulation (EPC). We examine hypotheses which could explain the evolution of EPC and discuss the different patterns of extra-pair mating. Received: 11 July 1997 / Accepted after revision: 23 May 1998  相似文献   
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The influence of microbial activity on the concentration and speciation of trace elements (TEs) was assessed in a study on the bioavailability of TEs for edible plants. A growth chamber experiment with spring wheat (Triticum aestivum cv. USU-Perigee) was conducted and the bulk (Bk) and the rhizosphere (Rz) soil components were collected at maturity. A characterization of the microbial activity and population was made by measuring the microbial biomass, enzymes (acid phosphatase, arylsulfatase, dehydrogenase and urease) and 16S rDNA DGGE profiles. In soil water extracts, major solutes (H(+), Ca, Mg, Na, NH(4), K, Cl, NO(3), SO(4), total N, DON and DOC) and trace elements (Al, As, Cd, Ce, Cr, Cu, Fe, Pb, Tl, and Zn) including monomeric Al species, free Cu(2+) and labile Zn were determined. The partition of the variation indicated that 12.1% of the distribution of TEs in the Bk soil was significantly and exclusively explained by chemical properties while this value was less than 0.1% for the Rz soil. To the contrary, microbial properties contributed significantly to 12.3% of the distribution of TEs in the Rz soil whereas it explained less than 0.1% for the Bk soil. Detailed redundancy analyses identified several potential mechanisms (e.g. weathering of primary mineral, solubilisation of sesquioxides, bacterial effect on the redox status) explaining the fate of TEs in the Bk and Rz soils. This study revealed that microbial activity is strongly associated to the speciation of trace elements in the Rz of edible plants and points to some microbial processes influencing TE speciation.  相似文献   
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The effect of soil properties on trace element (TE) extraction by the Fish Creek willow cultivar was assessed in a 4-month greenhouse experiment with two contrasted soils and two mycorrhizal treatments (Rhizophagus irregularis and natives). Aboveground tissues represented more than 82 % of the willow biomass and were the major sink for TE. Cadmium and Zn were concentrated in leaves, while As, Cu, Ni, and Pb were mostly found in roots. Willow bioconcentration ratios were below 0.20 for As, Cu, Ni, and Pb and reached 10.0 for Cd and 1.97 for Zn. More significant differences in willow biomass, TE concentrations, and contents were recorded between soil types than between mycorrhizal treatments. A slight significant increase in Cu extraction by willow in symbiosis with Rhizophagus irregularis was observed and was linked to increased shoot biomass. Significant regression models between TE in willow and soil properties were found in leaves (As, Ni), shoots (As, Cd, Cu, Ni), and roots (As, Cu, Pb). Most of the explanation was shared between soil water-soluble TE and fertility variables, indicating that TE phytoextraction is related to soil properties. Managing interactions between TE and major nutrients in soil appeared as a key to improve TE phytoextraction by willows.  相似文献   
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旅游者们越来越意识到交通的负面影响(包括噪音和其他类型的污染).繁重的交通会影响旅游目的地的娱乐或其他价值.对于旅游胜地以赢利为目的的管理者来说,交通方式和参观者的满意程度及再访愿望之间的关系正越来越重要.  相似文献   
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In numerous spider species, reproductive success of adult females has been shown to be positively correlated with their body mass. We suggest, however, that spiders may incur greater foraging costs as their body mass increases due to the numerous and complex locomotor bouts needed to build an orb-web. Such a body-mass-dependent cost should, in turn, affect the web-building decisions of spiders. In the laboratory, we tested the influence of body mass on energetic expenditure (measured as mass loss) during web-building behavior in Zygiella x-notata. Our results showed (1) that energetic costs associated with web-building were closely related to body mass and to web-building activity, and (2) that as their body mass increased, spiders reduced the amount of silk used per web, while their foraging effort simultaneously increased. This work gives new insights into web-building behavior and energy allocation strategies of weaving spiders.  相似文献   
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Global warming is perceived as one of the biggest global health risks of the twenty-first century and a threat to the achievement of sustainable (economic) development; especially in developing countries, climate change is believed to further exacerbate existing vulnerability to disease and food security risks, because their populations are, for example, more reliant on agriculture and more vulnerable to droughts and have a lower adaptive capacity. Furthermore, the health-related impacts of climate change are threatening to undo decades of development policies. The interactions between climate and non-climate factors are of vital importance in shaping human vulnerability to global warming. Climate change cannot be seen as ‘a stand-alone risk factor,’ but rather as an amplifier of existing health and food security risks and an additional strain on institutional infrastructures. In order to avoid a multiplication of health risks in the developing world, there is a need to better understand the multifaceted and complex linkages involved. This is further illustrated for two important climate change–induced health risks, namely malnutrition and malaria. As the amplification of existing and emerging health risks in the developing world might become the greatest tragedy of climate change, adaptation ranks high on developing countries’ agendas. Of particular importance are the discussions about the ‘Green Climate Fund,’ which aims to administer billions of dollars for mitigation and adaptation. Of course, making funds for adaptation available is an important first step, but we also need to ask ourselves the question how such adaptation policies and projects should take shape. This paper demonstrates that an adequate response to climate change health risks should take a systems approach toward adaptation, acknowledging the importance of the local context of the most vulnerable.  相似文献   
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