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121.
Indicator Taxa, Rapid Biodiversity Assessment, and Nestedness in an Endangered Ecosystem 总被引:14,自引:0,他引:14
Abstract: To prioritize areas for conservation, biologists and managers need information on species diversity in threatened habitats. The resources available for such inventories remain severely limited, increasing the need to develop speedier ways to estimate the status of target habitats. We present a study of the use of such techniques in the highly fragmented oak savannas of southern Ontario, including selection of indicator taxa, use of rapid biodiversity assessment based on morphospecies, and analysis of community structure. We found that butterflies and skippers can be used to predict richness among Hymenoptera in the study sites, which is consistent with the hypothesis that these easily surveyed Lepidoptera are good candidates for indicator status. Richness values for hymenoptera morphospecies in these savanna remnants were strongly correlated with species richness scores as estimated by systematists, although nonspecialists tended to "split" species into more than one morphospecies. Finally, both the Hymenoptera and Lepidoptera communities in these oak savannas exhibited a high degree of nestedness, suggesting that local extinctions, mostly undocumented, are important determinants of the richness patterns across these widely separated savanna study sites. We found no evidence of significant spatial autocorrelation, probably because of the wide separation of study sites. 相似文献
122.
We use recent data on transport costs in West Africa, including the added burden of bribes and enforced delays, to show how such costs represent a deterrent to investment in — and therefore the sustainability of — agricultural assets. We focus on data for two important tree crops in West Africa, cashew and shea. We also have data for the transport of onions between Niger and the urban market in Accra, Ghana. Our data allow us to predict plausible increases in farm‐gate prices from a reduction in transport costs and bribes. A 10% reduction in the total transport costs (actual costs plus corruption costs) of onions from Niger could result in a 12‐13% price increase to onion farmers. Similar elasticities are 2% for cashew in Ghana and 7% for shea in Mali. These feasible price increases would encourage farmers to improve onion production, and to protect and improve production from cashew and shea trees, thereby enhancing the sustainability of agro‐forestry in West Africa. We call these price increases the “sustainability dividend”. 相似文献
123.
Effects of implicit achievement motivation,expected evaluations,and domain knowledge on creative performance
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Jeremy L. Schoen 《组织行为杂志》2015,36(3):319-338
This paper explores the effect of achievement motivation on creative performance. I also describe how expectations of differing types of evaluations and knowledge of the domain moderate the relationship between implicit achievement motivation and creativity. Results suggest achievement motivation, measured implicitly, is related to creative performance. Additionally, the effect of achievement motivation at the implicit level on creative performance is moderated by expectation of evaluation and domain knowledge in a three‐way interaction. The main effect for achievement motivation, assessed at the implicit level, as a predictor of creative performance holds when controlling for other factors previously tested as predictors of creativity, including a self‐report assessment achievement motivation. I conclude by discussing the implications of this research and provide suggestions for future research opportunities. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
124.
Coal combustion and mercury pollution are closely linked, and this relationship is particularly relevant in China, the world's largest coal consumer. This paper begins with a summary of recent China-specific studies on mercury removal by air pollution control technologies and then provides an economic analysis of mercury abatement from these emission control technologies at coal-fired power plants in China. This includes a cost-effectiveness analysis at the enterprise and sector level in China using 2010 as a baseline and projecting out to 2020 and 2030. Of the control technologies evaluated, the most cost-effective is a fabric filter installed upstream of the wet flue gas desulfurization system (FF + WFGD). Halogen injection (HI) is also a cost-effective mercury-specific control strategy, although it has not yet reached commercial maturity. The sector-level analysis shows that 193 tons of mercury was removed in 2010 in China's coal-fired power sector, with annualized mercury emission control costs of 2.7 billion Chinese Yuan. Under a projected 2030 Emission Control (EC) scenario with stringent mercury limits compared to Business As Usual (BAU) scenario, the increase of selective catalytic reduction systems (SCR) and the use of HI could contribute to 39 tons of mercury removal at a cost of 3.8 billion CNY. The economic analysis presented in this paper offers insights on air pollution control technologies and practices for enhancing atmospheric mercury control that can aid decision-making in policy design and private-sector investments. 相似文献
125.
Touma JS Cox WM Tikvart JA 《Journal of the Air & Waste Management Association (1995)》2006,56(12):1716-1725
This paper summarizes information on the spatial and temporal variability of selected air toxics pollutants collected on a national basis primarily for a period encompassing 1990-2003. Spatial information on pollutant concentrations is characterized in terms of within-city and between-city variability. Temporal information is summarized as diurnal and seasonal variability and in multiyear trends. The information on variability is presented in the framework of a larger need for systematic documentation of information on air toxics pollutants to assess progress in air pollution control programs. 相似文献
126.
127.
Microbial fouling of a municipal water treatment system using reverse osmosis was investigated. From a combination of growth and molecular assays, it was discovered that the prefilter unit concentrated and facilitated microbial growth, and such growth led to microbial fouling of the reverse osmosis unit. Few cells were observed in the prefilter influent, but substantial microbial contamination was observed in the prefilter effluent, and this correlated with increasing headloss across the prefilter. The effluent caused microbial fouling of the leading elements of the reverse osmosis unit, as determined by reduced permeate flow, analysis of the elements, and assays of the membrane foulant. Both the introduction of microorganisms to the reverse osmosis unit from the prefilter unit and headloss across the prefilter could be effectively controlled through cleansing of the prefilter housing unit with sulfuric acid. Such treatments must be performed at appropriate intervals to prevent subsequent microbial growth in the prefilter unit. 相似文献
128.
Using precautionary principles when facing incomplete facts and causal conjectures raises the possibility of a Faustian bargain. This paper applies systems dynamics based on previously unavailable data to show how well intended precautionary policies for promoting food safety may backfire unless they are informed by quantitative cause-and-effect models of how animal antibiotics affect animal and human health. We focus on European Union and United States formulations of regulatory precaution and then analyze zoonotic infections in terms of the consequences of relying on political will to justify precautionary bans. We do not attempt a political analysis of these issues; rather, we conduct a regulatory analysis of precautionary legal requirements and use Quantitative Risk Assessment (QRA) to assess a set of policy outcomes. Thirty-seven years ago, the Joint Committee on the Use of Antibiotics in Animal Husbandry and Veterinary Medicine (the Swann Report) warned that uncontrolled use of similar antibiotics in humans and food animals could promote the emergence of resistant strains of foodborne bacteria that could endanger human health. Since then, many countries have either banned or restricted antibiotics as feed additives for promoting animal growth. Others, including the United States, have relied on prudent use guidelines and programs that reduce total microbial loads, rather than focusing exclusively on antibiotic-resistant bacteria. In retrospect, the regulatory strategy of banning or restricting animal antibiotic uses has had limited success: it has been followed in many cases by deteriorating animal health and increases in human illnesses and resistance rates. Conversely, a combination of continued prudent use of antibiotics to prevent and control animal infections, together with HACCP and other improvements, has been followed by large improvements in the microbial safety of chickens and other food animals in the United States, leaving both animals and people better off now than they were decades ago. A quantitative risk assessment model of microbiological risks (Campylobacter because of data availability) suggests that these outcomes may be more than coincidental: prudent use of animal antibiotics may actually improve human health, while bans on animal antibiotics, intended to be precautionary, inadvertently may harm human health. 相似文献
129.
We report a survey of the state of local authority archaeological services in Scotland following local government reorganization. Several service provision models are in place, including a new model of joint provision by councils of the former Strathclyde Region. Several councils which lacked a service before reorganization now buy it in from neighbouring councils. Some gaps in cover however persist. There are good reasons for the variety of models, and it would not be appropriate to seek to impose a single model. Planning guidance issued in 1994 has shifted the balance of service provision towards development control and away from other functions, as resources are squeezed. The implications of the Scottish Parliament are considered. 相似文献
130.
Jeremy Eppel 《Environment, Development and Sustainability》1999,1(1):41-53
The importance of sustainable development has been clearly recognised by the OECD Council at Ministerial Level. The Communiqué of the 1998 Ministerial Meeting states that Ministers agreed that the achievement of sustainable development is a key priority for OECD countries. They encouraged the elaboration of the Organisation's strategy for wide-ranging efforts over the next three years in the areas of climate change, technological development, sustainability indicators, and the environmental impact of subsidies.... Further, Ministers asked the OECD to enhance its dialogue with non-member countries in these areas and to engage them more actively, including through shared analyses and development of strategies for implementing sustainable development (OECD, 1998d).To help countries achieve the transition to sustainable development, a framework is required for the integration of economic, environmental and social policy. This was the main recommendation of the report in November 1997 to the OECD Secretary-General, Donald J. Johnston, of the High-Level Advisory Group on the Environment (OECD, 1997b). The OECD and its affiliates (including the International Energy Agency (IEA), the Nuclear Energy Agency (NEA), the Development Centre and the European Conference of Ministers of Transport (ECMT)) are well equipped with the broad, multidisciplinary expertise to assist Member governments in this task. Work on sustainable development encompasses the full range of activities of the Organisation: macro and micro-economic analysis; environmental policy; labour markets, education, health and social policies; agricultural and fisheries policies; energy policy; technology policy; regional, local and urban policies; and development co-operation. Activities with non-members add an essential global perspective. The challenge is to move beyond a sectoral approach to integrated policies, and to exploit potential synergies and interrelationships between this wide range of competencies. The aim is to move as far as possible towards the harmonisation and integration of policies within an overall economic framework. 相似文献