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391.
The contents from thick-billed murre (Uria lomvia) eggs collected at four Alaskan colonies in 2002 were analyzed for organic contaminants and carbon δ13C) and nitrogen (δ1?N) stable isotopes. Contaminant concentrations in the eggs varied from below detection limits to 230 ng g?1 wet mass for 4,4'-DDE in one egg from St Lazaria Island in the Gulf of Alaska. Eggs from this colony generally contained higher levels of contaminants and exhibited significantly different patterns compared to eggs from the Bering and Chukchi seas. Stable isotope values also varied geographically; however, these differences appeared to be related to differences in C and N baselines in the food webs instead of differences in prey. Contaminant and stable isotope correlations were inconclusive, suggesting that better information on regional food web differences and differential offloading of contaminants and stable isotopes to the eggs must be obtained before these kinds of data can be fully incorporated into seabird egg contaminant monitoring programs.  相似文献   
392.
This exploratory case study examines how one hospital learned from an adverse event (AE), a medication overdose that seriously injured a patient. Using qualitative data analysis, we examined how four professional groups reacted to the AE: physicians, nurses, pharmacists, and representatives from the combined quality assurance and risk management departments. Following the AE, each professional group classified the event differently, assessed a different segment of history, made decisions about different issues, and chose different courses of action. Despite these differences, the physician, nursing and pharmacy management teams all decided on which solutions to implement before the first root cause analysis meeting was convened. Indeed, to understand how the hospital implemented changes in the aftermath of the AE, it was necessary to examine the learning from near misses and other warnings that preceded it. This case highlights the importance of the politics of organizational learning and raises theoretical and practical questions about how hospitals learn from potential and actual adverse events.  相似文献   
393.
Burnout is a multidimensional syndrome that occurs primarily in professions where practitioners are subjected to stress associated with direct interpersonal contact with clients. Previous research indicates that working as a real estate broker is a particularly stressful form of work. Considering the potentially harmful effect of burnout on real estate brokers, resulting in a range of negative impacts, it is important to identify those factors emanating from either the individual or their work environment that contribute to this syndrome. The paper presents a study that used a questionnaire survey to determine the individual demographics, work and intrapersonal characteristics that affect burnout in real estate brokers. A sample of 305 real estate brokers was obtained in Western Australia. Hierarchical regression was then employed to identify predictors of burnout (i.e. emotional exhaustion, depersonalisation, and personal accomplishment) and sense of coherence (SOC). The analysis revealed the following: emotional exhaustion was associated with lower age, higher numbers of hours worked, and lower SOC; higher depersonalisation was associated with lower age and SOC; higher personal accomplishment was associated with a greater number of visits to clients per week, the presence of postgraduate qualification and a high SOC. The results provide insight to guide health promotion for real estate brokers so as to enhance their psychological and physical well-being, thus making a contribution to improving their overall performance levels and effectiveness.  相似文献   
394.
This collaborative study examined urbanization and impacts on area streams while using the best available sediment and erosion control (S&EC) practices in developing watersheds in Maryland, United States. During conversion of the agricultural and forested watersheds to urban land use, land surface topography was graded and vegetation was removed creating a high potential for sediment generation and release during storm events. The currently best available S&EC facilities were used during the development process to mitigate storm runoff water quality, quantity, and timing before entering area streams. Detailed Geographic Information System (GIS) maps were created to visualize changing land use and S&EC practices, five temporal collections of LiDAR (light detection and ranging) imagery were used to map the changing landscape topography, and streamflow, physical geomorphology, and habitat data were used to assess the ability of the S&EC facilities to protect receiving streams during development. Despite the use of the best available S&EC facilities, receiving streams experienced altered flow, geomorphology, and decreased biotic community health. These impacts on small streams during watershed development affect sediment and nutrient loads to larger downstream aquatic ecosystems such as the Chesapeake Bay.  相似文献   
395.
A pilot‐scale study was performed using a palladium‐catalyzed and polymer‐coated nanoscale zero‐valent iron (ZVI) particle suspension at the Naval Air Station in Jacksonville, Florida. A total of 300 pounds of nanoscale ZVI particle suspension was injected via a gravity feed and recirculated through a source area containing chlorinated volatile organic compounds (VOCs). The recirculation created favorable mixing and distribution of the iron suspension and enhanced the mass transfer of sorbed and nonaqueous constituents into the aqueous phase, where the contaminants could be reduced. Between 65 and 99 percent aqueous‐phase VOC concentration reduction occurred, due to abiotic degradation, within five weeks of the injection. The rapid abiotic degradation processes then yielded to slower biological degradation as subsequent decreases in ‐elimination parameters were observed—yet favorable redox conditions were maintained as a result of the ZVI treatment. Post‐treatment analyses revealed cumulative reduction of soil contaminant concentrations between 8 and 92 percent. Aqueous‐phase VOC concentrations in wells side gradient and downgradient of the source were reduced up to 99 percent and were near or below applicable regulatory criteria. These reductions, coupled with the generation of innocuous by‐products, indicate that nanoscale ZVI effectively degraded contamination and reduced the mass flux from the source, a critical metric identified for source treatment. A summary of this project was recently presented at the US EPA Workshop on Nanotechnology for Site Remediation in Washington, D.C., on October 21–22, 2005. This case study supplied evidence that nanoscale zero valent iron, an emerging remediation technology, has been implemented successfully in the field. More information about this workshop and this presentation can be found at www.frtr.gov/nano/index.htm. © 2006 Wiley Periodicals, Inc.  相似文献   
396.
Life cycle assessment (LCA) provides a concept, framework, and method to identify and evaluate the environmental burdens of products and processes. An ongoing concern of companies trying to implement LCA is the value of LCA in supporting actual decisions versus the resources and time needed to conduct a “full” LCA. In response to these concerns, there has been a lot of activity surrounding the “streamlining” of LCA to keep it more manageable yet provide useful and acceptably accurate results. This article explores the concept of streamlining, discusses where and how streamlining decisions can be made in an LCA, and presents issues related to conducting more streamlined LCAs. Due to the wide variety of purposes and scenarios in which LCAs are conducted, it is difficult to devise a one-size-fits-all method for streamlining. Instead, we have focused on presenting the streamlining options in the context of major decision points that are common to most LCAs.  相似文献   
397.
The Clean Development Mechanism (CDM) is a facility for trading `certified emission reductions (CERs) between developing and developed countries, thus saving non-renewable carbon emissions by promoting renewable energy, energy efficiency and/or carbon sequestration projects in LDC's. The purpose of the CDM is to help these latter countries meet their obligations under the Kyoto Protocol while at the same time promoting “sustainable” development in the former countries, thereby reducing the build-up of greenhouse gases (GHG). This paper examines the progress in achieving a workable CDM in time for the first commitment period (2008–2012), and the kinds of initiatives that can be pursued in the agricultural, land-use and forestry sector in tropical countries. The critical element for the success of the CDM is the participation of a broad cross-section of buyers (ultimately from developed countries) and sellers (from developing countries) of CERs. Trading is the final step, which starts with project formulation, through successful implementation and then certification. This paper lays out a market-based framework for promoting CDM transactions between private sector project developers and traders and public sector policy makers, with regulators, governed by CDM rules, overseeing the smooth running of the CDM. However, as there are numerous players; it is proposed that trial CDM projects be demonstrated with the support of National/International bodies to iron out the problems and come up with practical solutions so that carbon trading can become a reality. Most rules for the CDM were clarified at the 7th Conference of Parties (CP) in October/November of 2001 in Marrakesh. An executive Board (EB) was appointed and this EB is in charge of proposing workable ground rules to promote the CDM. These have to be submitted for approval by the 8th CP in late 2002. Three broad kinds of projects qualify for the CDM, these are: renewable energy projects that will be alternatives to fossil fuel projects; sequestration projects that offset GHG emissions; and energy efficient projects that will decrease the emissions of GHG. It is possible to have a combination of these initiatives. A fourth type covering GHG reduction is omitted. As elaborated in the text, in order to qualify for the CDM, the proposed projects may have to have additional costs when compared to the alternative(s). Two time frames have been agreed for CDM projects to qualify for the first commitment period, namely 7 years (with an option of two 7-year renewals) and 10 years. Also, for land-use, land-use change and forestry projects only afforestation/reforestation initiatives are recognized as being permissible for the first commitment period. These rules seem rather shortsighted, as forestry and/or renewable energy projects usually require more than 21 years to be fully effective. Also, the major cause of deforestation is clearing land for agriculture, not harvesting wood. Therefore, improving agricultural productivity may be the best way to reduce deforestation and its subsequent release of GHGs. These conditionalities should be re-examined when rules for the second commitment period are decided. However, various agricultural and land-use projects are discussed under the existing guidelines which could qualify as CDM projects in the first period.  相似文献   
398.
Liberty State Park in New Jersey,USA,is a "brownfield" site containing various levels of contaminants.To investigate metal uptake and distributions in plants on the brownfield site,Phragmites australis and Typha latifolia were collected in Liberty State Park during the growing season(May–September)in 2011 at two sites with the high and low metal loads,respectively.The objective of this study was to understand the metal(Fe,Mn,Cu,Pb and Zn)concentration and spatial distributions in P.australis and T.latifolia root systems with micro-meter scale resolution using synchrotron X-ray microfluorescence(μXRF)and synchrotron X-ray computed microtomography(μCMT)techniques.The root structure measurement by synchrotron μCMT showed that high X-ray attenuation substance appeared in the epidermis.Synchrotron μXRF measurement showed that metal concentrations and distributions in the root cross-section between epidermis and vascular tissue were statistically different.Significant correlations were found between metals(Cu,Mn,Pb and Zn)and Fe in the epidermis,implying that metals were scavenged by Fe oxides.The results from this study suggest that the expression of metal transport and accumulation within the root systems may be element specific.The information derived from this study can improve our current knowledge of the wetland plant ecological function in brownfield remediation.  相似文献   
399.
A methodology to perform consequence analysis associated with liquefied natural gas (LNG) for a deepwater port (DWP) facility has been presented. Analytical models used to describe the unconfined spill dynamics of LNG are discussed. How to determine the thermal hazard associated with a potential pool fire involving spilled LNG is also presented. Another hazard associated with potential releases of LNG is the dispersion of the LNG vapor. An approach using computational fluid dynamics tools (CFD) is presented. The CFD dispersion methodology is benchmarked against available test data. Using the proposed analysis approach provides estimates of hazard zones associated with newly proposed LNG deepwater ports and their potential impact to the public.  相似文献   
400.
The Mann–Kendall test has been proposed as a nonparametric method to evaluate trends in long-term water quality datasets with missing values, serial correlation, and non-normality. However, this test has rarely been used to evaluate long-term trends in biological data. In this study, we used the Mann–Kendall test to evaluate trends in 15?years of data on benthic macroinvertebrate communities from 17 Precambrian Shield lakes. We also used the van Belle and Hughes test of trend homogeneity to assess whether common among-lake temporal trends existed. We assumed that evidence of a common regional trend among lakes would support the hypothesis of long-term biological recovery from past acidification. We found decreasing proportions of Chironomidae and increasing proportions of Ephemeroptera, Plecoptera, and Trichoptera (EPT) in both single-lake and multi-lake trend analysis. Moreover, six of the nine lakes with significant trends in more than one benthos metric displayed a significant decrease in Chironomidae and increase in EPT concurrently, indicating a shift towards more acid-sensitive taxa. Weak trends in several of the biological metrics indicated that recovery in these lakes has been impeded. Results of this study indicate that the Mann–Kendall and van Belle and Hughes trend tests are useful statistical tools to evaluate long-term patterns in biological data.  相似文献   
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