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51.
Excessive sedimentation in streams and rivers remains a pervasive problem for the protection of aquatic habitat and the sustainability of aquatic communities. Whereas water quality criteria have been determined for suspended sediments in many jurisdictions across North America, comparably little has been done for deposited (also known as bedded) sediments. Through Canada's National Agri-Environmental Standards Initiative, assessment techniques and analytical tools were developed for estimating environmental thresholds for deposited sediments in agricultural watersheds in New Brunswick (NB) and Prince Edward Island (PEI) in the Atlantic Maritimes of Canada. Physical thresholds were developed through assessment of geomorphic metrics, which were then analyzed using y-intercept and 25th percentile approaches. For NB, there was strong agreement in physical thresholds for both analytical approaches (e.g., percent fines <2 mm were 7.5 for y-intercept and 6.9 for 25th percentile approaches). In contrast, physical thresholds for PEI differed considerably between approaches (e.g., percent fines <2 mm were 6.1 for y-intercept and 19.6 for 25th percentile approaches), likely due to a narrower range in agricultural land cover. Cross-calibration of our provisional physical thresholds for NB with ecological (i.e., benthic macroinvertebrate) assessments show that ecological thresholds, calculated as change-points in relationships between Ephemeroptera-Plecoptera-Trichoptera relative abundance or Modified Family Biotic Index and geomorphic criteria, were more liberal than physical thresholds. These results suggest that provisional thresholds developed using geomorphic criteria should demarcate change from the least disturbed condition and reduce the risk of sedimentation degrading benthic ecosystems.  相似文献   
52.
The metabolism of the antibacterial fluoroquinolone drug flumequine by Cunninghamella elegans was investigated using cultures grown in Sabouraud dextrose broth with 308microM flumequine. The cultures were extracted with ethyl acetate; metabolites were separated by high-performance liquid chromatography and identified by mass spectrometry and proton nuclear magnetic resonance spectroscopy. Flumequine was transformed to two diastereomers of 7-hydroxyflumequine (23 and 43% of the total chromatographic peak area at 280nm) and 7-oxoflumequine (11% of the total peak area). This is the first time that the two 7-hydroxy diastereomers have been characterized structurally; the hydroxyflumequines are known to have less antimicrobial activity than flumequine.  相似文献   
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A major justification of environmental management research is that it helps practitioners, yet previous studies show it is rarely used to inform their decisions. We tested whether conservation practitioners focusing on bird management were willing to use a synopsis of relevant scientific literature to inform their management decisions. This allowed us to examine whether the limited use of scientific information in management is due to a lack of access to the scientific literature or whether it is because practitioners are either not interested or unable to incorporate the research into their decisions. In on‐line surveys, we asked 92 conservation managers, predominantly from Australia, New Zealand, and the United Kingdom, to provide opinions on 28 management techniques that could be applied to reduce predation on birds. We asked their opinions before and after giving them a summary of the literature about the interventions’ effectiveness. We scored the overall effectiveness and certainty of evidence for each intervention through an expert elicitation process—the Delphi method. We used the effectiveness scores to assess the practitioners’ level of understanding and awareness of the literature. On average, each survey participant changed their likelihood of using 45.7% of the interventions after reading the synopsis of the evidence. They were more likely to implement effective interventions and avoid ineffective actions, suggesting that their intended future management strategies may be more successful than current practice. More experienced practitioners were less likely to change their management practices than those with less experience, even though they were not more aware of the existing scientific information than less experienced practitioners. The practitioners’ willingness to change their management choices when provided with summarized scientific evidence suggests that improved accessibility to scientific information would benefit conservation management outcomes. El Efecto de la Evidencia Científica sobre las Decisiones de Manejo de Quienes Practican la Conservación  相似文献   
55.
Graham W. Prescott  William J. Sutherland  Daniel Aguirre  Matthew Baird  Vicky Bowman  Jake Brunner  Grant M. Connette  Martin Cosier  David Dapice  Jose Don T. De Alban  Alex Diment  Julia Fogerite  Jefferson Fox  Win Hlaing  Saw Htun  Jack Hurd  Katherine LaJeunesse Connette  Felicia Lasmana  Cheng Ling Lim  Antony Lynam  Aye Chan Maung  Benjamin McCarron  John F. McCarthy  William J. McShea  Frank Momberg  Myat Su Mon  Than Myint  Robert Oberndorf  Thaung Naing Oo  Jacob Phelps  Madhu Rao  Dietrich Schmidt‐Vogt  Hugh Speechly  Oliver Springate‐Baginski  Robert Steinmetz  Kirk Talbott  Maung Maung Than  Tint Lwin Thaung  Salai Cung Lian Thawng  Kyaw Min Thein  Shwe Thein  Robert Tizard  Tony Whitten  Guy Williams  Trevor Wilson  Kevin Woods  Alan D. Ziegler  Michal Zrust  Edward L. Webb 《Conservation biology》2017,31(6):1257-1270
Political and economic transitions have had substantial impacts on forest conservation. Where transitions are underway or anticipated, historical precedent and methods for systematically assessing future trends should be used to anticipate likely threats to forest conservation and design appropriate and prescient policy measures to counteract them. Myanmar is transitioning from an authoritarian, centralized state with a highly regulated economy to a more decentralized and economically liberal democracy and is working to end a long‐running civil war. With these transitions in mind, we used a horizon‐scanning approach to assess the 40 emerging issues most affecting Myanmar's forests, including internal conflict, land‐tenure insecurity, large‐scale agricultural development, demise of state timber enterprises, shortfalls in government revenue and capacity, and opening of new deforestation frontiers with new roads, mines, and hydroelectric dams. Averting these threats will require, for example, overhauling governance models, building capacity, improving infrastructure‐ and energy‐project planning, and reforming land‐tenure and environmental‐protection laws. Although challenges to conservation in Myanmar are daunting, the political transition offers an opportunity for conservationists and researchers to help shape a future that enhances Myanmar's social, economic, and environmental potential while learning and applying lessons from other countries. Our approach and results are relevant to other countries undergoing similar transitions.  相似文献   
56.
Small tropical islands are widely recognized as having high exposure and vulnerability to climate change and other natural hazards. Ocean warming and acidification, changing storm patterns and intensity, and accelerated sea-level rise pose challenges that compound the intrinsic vulnerability of small, remote, island communities. Sustainable development requires robust guidance on the risks associated with natural hazards and climate change, including the potential for island coasts and reefs to keep pace with rising sea levels. Here we review these issues with special attention to their implications for climate-change vulnerability, adaptation, and disaster risk reduction in various island settings. We present new projections for 2010–2100 local sea-level rise (SLR) at 18 island sites, incorporating crustal motion and gravitational fingerprinting, for a range of Intergovernmental Panel on Climate Change global projections and a semi-empirical model. Projected 90-year SLR for the upper limit A1FI scenario with enhanced glacier drawdown ranges from 0.56 to 1.01 m for islands with a measured range of vertical motion from ?0.29 to +0.10 m. We classify tropical small islands into four broad groups comprising continental fragments, volcanic islands, near-atolls and atolls, and high carbonate islands including raised atolls. Because exposure to coastal forcing and hazards varies with island form, this provides a framework for consideration of vulnerability and adaptation strategies. Nevertheless, appropriate measures to adjust for climate change and to mitigate disaster risk depend on a place-based understanding of island landscapes and of processes operating in the coastal biophysical system of individual islands.  相似文献   
57.
Behavior-based safety has been found universally efficacious when evaluated under controlled conditions. The Curtin Trial aimed to test the general acceptability of behavior-based safety in Australian industry. A 50% failure rate was observed. This paper presents the results of a qualitative analysis of observed managerial behavior in relation to program effectiveness. Field notes taken in the course of 325 hours of participant observation during implementation of behavior-based safety in 9 work areas were analyzed qualitatively and categorized. These data were compared with statistical results of the safety program's effectiveness on improving safe practices and good housekeeping. Nine dimensions to managerial behavior were identified which were associated with program effectiveness. A relatively small number of studies investigating organizational characteristics and safety have found generally similar social environmental features to those observed in this study. Behavior-based safety appears to be effective only in organizations with recognizable managerial styles.  相似文献   
58.
Lead in grain size fractions of road-deposited sediment   总被引:13,自引:0,他引:13  
Road-deposited sediment (RDS) is an important environmental medium for assessing contaminant levels in urban systems. Their atmospheric resuspension has significant implications for human health, and storm water transport can directly impact aquatic biota. Data from 20 RDS samples from Palolo Valley, Oahu, Hawaii, were fractionated into six grain-size classes and analyzed for Pb using a weak HCl (0.5 M) digestion. Data indicate significant Pb contamination in all samples. Median labile Pb concentration (n = 120) was 170 mg/kg, with a range from 4 to 1750 mg/kg. The five sediment fractions < 1000 microm had statistically similar Pb concentrations, but all were significantly greater than the coarsest fraction examined (1000-2000 microm). Silt plus clay ( < 63 microm) was the single most important mass component with 38% of the total sediment stored in this fraction. Mass of sediment < 63 microm combined with a median labile Pb concentration of 222 mg/kg accounted for 51% of the total Pb load stored in road sediments. These findings are significant from an environmental management perspective, and these issues are discussed in light of street sweeper sediment grain size removal efficiencies.  相似文献   
59.
The Kyoto Protocol requires the U.S.to reduce the rate of emissions of six greenhousegases (GHG) to 93% of their 1990 rate and to achievethis target by the 2008 to 2012 commitment period. This study assesses the magnitude of change needed inthe U.S. economy and, specifically, in the U.S. energysector, to achieve and maintain the target establishedby the Kyoto Protocol. A simple carbon (C)emissions-energy model is explained in this analysisusing four key variables. Current and future trendsin C emissions are explained by: the carbon/energy(C/E) ratio, Gross Domestic Product growth, energyprices and an energy trend variable. Potential GHGmitigation policy actions affect C emissionsindirectly by affecting at least one of these keyvariables. The analysis concludes that reducingfossil energy use in the U.S. to meet the Kyoto GHGemissions reduction target would be very costly. Technological progress that reduces C emissions wouldnot be fully sufficient without prematurely abandoningproductive capital equipment. Energy price increasesof about 14% per year, or declines in economic growthof almost 5% per year, could reduce energy demand andassociated C emissions enough to achieve the terms ofthe Kyoto Protocol.  相似文献   
60.
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