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61.
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The Transition movement has experienced remarkable growth in its first decade, yet there remains considerable doubt about its ability to appeal to a diverse audience. To date, few studies have explicitly examined diversity of participation in the movement. Addressing this gap in the literature, a case study is presented of Transition Town Tooting (TTT). Results from a mixed methods approach comprising semi-structured interviews, participant observation, and a quantitative survey indicate that the demographic profiles of TTT participants do not represent the diversity of the Tooting population. This disparity is exacerbated by TTT’s ‘passive’ approach to inclusivity within the core group. Reflecting upon the implications for Transition’s goal of local resilience, it is suggested that, particularly within dense urban communities, initiatives may have more potential for engaging diverse voices through a local ‘brokering’ role between various subcommunities.  相似文献   
63.
Despite heavy insecticide usage in urban areas, only a few studies have investigated the impact of current-use insecticides on benthic invertebrates in urban streams. The objective of this study was to measure the presence and concentration of current-use pesticides in sediments of residential streams in central Texas. Additionally, toxicity of these sediments to Hyalella azteca was evaluated. Sediment samples were collected from several sites in urban streams over the course of a year, of which, 66% had greater than one toxic unit (TU) of insecticide. Bifenthrin was the greatest contributor accounting for 65% of the TUs, and sediment toxicity to H. azteca correlated with the magnitude of total insecticides and bifenthrin TUs. The results of this study further raise concerns over the environmental consequences posed by many current-use insecticides, especially pyrethroids, in urban settings.  相似文献   
64.
Energy efficiency and conservation for individual Americans   总被引:1,自引:0,他引:1  
Americans make up only 4% of the world population, yet currently consume 25% of the world’s fossil fuels. The U.S. imports 63% of its oil and it is predicted that by 2020 the U.S. will be importing 95% of its oil resources. Over the past century, ample and affordable supplies of fossil fuels have powered the growth and prosperity of the economies of the US and other countries. Within this century, world oil supplies will decline while demand is projected to continue to increase, suggesting that we will have to transition to different fuels or become much more energy efficient or both. Looking ahead to the near decades, estimates are that consumers will have to reduce their energy use by at least 50%. This reduction will be necessary in large part due the decline in the availability of conventional oil and gas, but also because the U.S. population will continue to grow in number. Although government action is important, individuals too often discount their ability to make significant contributions to solving such major problems. This investigation identifies how informed and concerned individuals can collectively conserve fossil energy. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. An erratum to this article can be found at  相似文献   
65.
Measurements of concentrations and size distributions of particles 4.7 to 160 nm were taken using an SMPS during the bonfire and firework celebrations on Bonfire Night in Leeds, UK, 2006. These celebrations provided an opportunity to study size distributions in a unique atmospheric pollution situation during and following a significant emission event due to open biomass burning. A log-normal fitting program was used to determine the characteristics of the modal groups present within hourly averaged size distributions. Results from the modal fitting showed that on bonfire night the smallest nucleation mode, which was present before and after the bonfire event and on comparison weekends, was not detected within the size distribution. In addition, there was a significant shift in the modal diameters of the remaining modes during the peak of the pollution event. Using the concept of a coagulation sink, the atmospheric lifetimes of smaller particles were significantly reduced during the pollution event, and thus were used to explain the disappearance of the smallest nucleation mode as well as changes in particle count mean diameters. The significance for particle mixing state is discussed.  相似文献   
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A simplistic aggregate model of global economic activity supports a 50-year visioning exercise with targets defined in terms of aggregate measures of global equity (convergence) and sustainability (contraction). Some ambitious combinations of these targets turn out to be infeasible even under the most favorable modeling assumptions. No contraction target (no reduction in fossil fuel consumption relative to the present) was possible, for example, if international capital transfers pushed per capita incomes in low-income countries above 33% of levels achieved in high-income countries. Lower prices for renewable alternatives to exhaustible resources generally made sustainability targets easier to achieve, but lower prices for renewable resources also made equity targets more difficult to achieve. Improved substitution between capital and labor made equity targets easier to achieve in relative terms, but improved substitution between capital and labor could make any given sustainability target more or less difficult to achieve. All the results suggest that it is possible to overstate the purported conflict between achieving sustainability and equity targets. The very transfers of international capital that would promote relative equity between high-income and low-income countries could also work to spread the incidence of achieving any sustainability target more evenly across their boundaries.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   
68.
Regional Environmental Change - Adaptive and multi-level governance is often called for in order to improve the management of complex issues such as the provision of natural resources and ecosystem...  相似文献   
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Coffey EE  Froyd CA  Willis KJ 《Ecology》2011,92(4):805-812
The Galápagos Islands are globally renowned for their ecological value and as a world symbol of scientific discovery; however the native biodiversity of this unique region is currently under threat. One of the primary concerns is the detrimental impact of approximately 750 nonnative plants introduced over the last 500 years of human presence in the archipelago. In addition to these known introduced species, there are an additional 62 vascular plants classified as "doubtful natives," where native status remains unclear. To help address the questions of provenance regarding these doubtfully native species and their impact on highland ecosystems over the past 500-1000 years, we analyzed plant macrofossils in sedimentary records. Appropriate species classification (native or introduced) was determined using baseline data of species presence on the islands. We confirmed that six plants (Ageratum conyzoides, Solanum americanum, Ranunculus flagelliformis, Brickellia diffusa, Galium canescens, and Anthephora hermaphrodita) once considered doubtful natives or introduced are actually native to the Galápagos flora. These results have relevance not just for the Galápagos but also many other oceanic islands in demonstrating the application of palaeobotanical data to conserving and restoring native biodiversity.  相似文献   
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