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61.
This article explores the drivers, benefits, and challenges to climate change adaptation in Bangladesh. It specifically investigates the “Community Based Adaptation to Climate Change through Coastal Afforestation Program,” a 5-year $5 million adaptation scheme being funded and implemented in part by the Government of Bangladesh, United Nations Development Program, and Global Environment Facility. The article explores how the CBACC-CA builds various types of adaptive capacity in Bangladesh and the extent its design and implementation offers lessons for other adaptation programs around the world. The first part of the study begins by describing its research methods consisting of research interviews, site visits, and a literature review. It then summarizes six primary sectors vulnerable to climate change in Bangladesh: water resources and coastal zones, infrastructure and human settlements, agriculture and food security, forestry and biodiversity, fisheries, and human health. The article next describes the genesis and background behind the CBACC-CA, with an emphasis on components that promote capacity development, demonstration projects, risk reduction, and knowledge management. The article concludes that technology by itself is only a partial component of successful adaptation efforts, and that multiple and integrated adaptation measures that cut across sectors and social, institutional, and infrastructural dimensions are needed to truly build resilience and effectiveness.  相似文献   
62.
Biodissolution experiments on cinnabar ore(mercury sulphide and other sulphide minerals,such as pyrite) were performed with microorganisms extracted directly from soil. These experiments were carried out in closed systems under aerobic and anaerobic conditions with 2 different soils sampled in French Guyana. The two main objectives of this study were(1) to quantify the ability of microorganisms to mobilize metals(Fe, Al, Hg) during the dissolution of cinnabar ore, and(2) to identify the links between the type and chemical properties of soils, environmental parameters such as season and the strategies developed by indigenous microorganisms extracted from tropical natural soils to mobilize metals.Results indicate that microbial communities extracted directly from various soils are able to(1) survive in the presence of cinnabar ore, as indicated by consumption of carbon sources and,(2) leach Hg from cinnabar in oxic and anoxic dissolution experiments via the acidification of the medium and the production of low molecular mass organic acids(LMMOAs). The dissolution rate of cinnabar in aerobic conditions with microbial communities ranged from 4.8 × 10~(-4) to 2.6 × 10~(-3) μmol/m~2/day and was independent of the metabolites released by the microorganisms. In addition, these results suggest an indirect action by the microorganisms in the cinnabar dissolution. Additionally, because iron is a key element in the dynamics of Hg, microbes were stimulated by the presence of this metal,and microbes released LMMOAs that leached iron from iron-bearing minerals, such as pyrite and oxy-hydroxide of iron, in the mixed cinnabar ore.  相似文献   
63.
活性氮和世界:200年的变化   总被引:101,自引:0,他引:101  
本文通过将19世纪后期和20世纪后期的氮流动情况进行对比,分析了食物和能源生产对全球氮循环的影响.我们虽然对人类产生的活性氮的数量及其释放到环境所产生的主要影响有了充分的认识,但是,我们对于环境库中氮的累积速度缺乏了解,由于积累在环境中的氮具有阶式效应,因此,对其在环境中的积累尚有不明之处.未来活性氮的产生、分布状况及其形成速度增加的可能性(尤其是在亚洲)存在巨大的区域性差异,因而需要制定"总活性氮措施",以优化食物和能源生产,保护环境系统.  相似文献   
64.
In 1964, Walter Rothenbuhler proposed a two-gene model to explain phenotypic variance in the remarkable behavior in which honey bee workers remove dead brood from their colonies. Rothenbuhler's model proposed that one locus controls the uncapping of brood cells containing dead pupae, while a second controls the removal of the cell contents. We show here, through molecular techniques and quantitative trait loci (QTL) linkage mapping, that the genetic basis of hygienic behavior is more complex, and that many genes are likely to contribute to the behavior. In our cross, we detected seven suggestive QTLs associated with hygienic behavior. Each detected QTL controlled only 9-15% of the observed phenotypic variance in the character.  相似文献   
65.
Numerous studies have focussed on the relationship between female choice and the multiple exaggerated sexual traits of males. However, little is known about the ability of males to actively enhance specific components of their display in response to the loss of one component. We investigated the capacity of male satin bowerbirds (Ptilonorhynchus violaceus) to respond to the loss of one of their sexual signals by performing an experiment in which we removed decorations at their bowers. We found that males compensated for decoration loss by increasing bower construction behaviour and decreasing their latency to bower painting. These results are novel because they suggest that males can assess the quality of their own display and make decisions about how to augment their displays. We discuss these results in the context of previous studies of mate choice in satin bowerbirds, as both of the supplementary behaviours we observed are known correlates of male mating success.  相似文献   
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67.
Food and Environmental Virology - Human noroviruses impose a considerable health burden globally. Here, a flow cytometry approach designed for their detection in biological waste and food samples...  相似文献   
68.
During 2010–2011, a study was conducted in Sequoia and Kings Canyon National Parks (SEKI) to evaluate the influence of pack animals (stock) and backpackers on water quality in wilderness lakes and streams. The study had three main components: (1) a synoptic survey of water quality in wilderness areas of the parks, (2) paired water quality sampling above and below several areas with differing types and amounts of visitor use, and (3) intensive monitoring at six sites to document temporal variations in water quality. Data from the synoptic water quality survey indicated that wilderness lakes and streams are dilute and have low nutrient and Escherichia coli concentrations. The synoptic survey sites were categorized as minimal use, backpacker-use, or mixed use (stock and backpackers), depending on the most prevalent type of use upstream from the sampling locations. Sites with mixed use tended to have higher concentrations of most constituents (including E. coli) than those categorized as minimal-use (P ≤ 0.05); concentrations at backpacker-use sites were intermediate. Data from paired-site sampling indicated that E. coli, total coliform, and particulate phosphorus concentrations were greater in streams downstream from mixed-use areas than upstream from those areas (P ≤ 0.05). Paired-site data also indicated few statistically significant differences in nutrient, E. coli, or total coliform concentrations in streams upstream and downstream from backpacker-use areas. The intensive-monitoring data indicated that nutrient and E. coli concentrations normally were low, except during storms, when notable increases in concentrations of E. coli, nutrients, dissolved organic carbon, and turbidity occurred. In summary, results from this study indicate that water quality in SEKI wilderness generally is good, except during storms; and visitor use appears to have a small, but statistically significant influence on stream water quality.  相似文献   
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