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81.
The synthesis of five chlorinated dibenzofurans and three chlorinated animodibenzofurans from easily available diphenyl ethers is described. Also reported is the preparation of the diphenyl ethers. The 1H-NMR and mass spectra data for the compounds are also reported.  相似文献   
82.
White CR  Cassey P  Blackburn TM 《Ecology》2007,88(2):315-323
The debate about the value of the allometric scaling exponent (b) relating metabolic rate to body mass (metabolic rate = a x mass(b)) is ongoing, with published evidence both for and against a 3/4-power scaling law continuing to accumulate. However, this debate often revolves around a dichotomous distinction between the 3/4-power exponent predicted by recent models of nutrient distribution networks and a 2/3 exponent predicted by Euclidean surface-area-to-volume considerations. Such an approach does not allow for the possibility that there is no single "true" exponent. In the present study, we conduct a meta-analysis of 127 interspecific allometric exponents to determine whether there is a universal metabolic allometry or if there are systematic differences between taxa or between metabolic states. This analysis shows that the effect size of mass on metabolic rate is significantly heterogeneous and that, on average, the effect of mass on metabolic rate is stronger for endotherms than for ectotherms. Significant differences between scaling exponents were also identified between ectotherms and endotherms, as well as between metabolic states (e.g., rest, field, and exercise), a result that applies to b values estimated by ordinary least squares, reduced major axis, and phylogenetically correct regression models. The lack of support for a single exponent model suggests that there is no universal metabolic allometry and represents a significant challenge to any model that predicts only a single value of b.  相似文献   
83.
Regional Environmental Change - This article describes the design of a new model-based assessment framework to identify and analyse possible future trajectories of agricultural development and...  相似文献   
84.
Environmental Science and Pollution Research - In 2008, the Mulberry River, a National Wild and Scenic River, was listed as impaired due to low pH (below pH 6.0). Over the last...  相似文献   
85.
Ecosystem-based Management (EBM) is an approach that includes different management priorities and requires a balance between anthropogenic and ecological resource demands. Indicators can be used to monitor ecosystem status and trends, and assess whether projects and/or programs are leading to the achievement of management goals. As such, the careful selection of a suite of indicators is a crucial exercise. In this paper we describe an indicator evaluation and selection process designed to support the EBM approach in Puget Sound. The first step in this process was the development of a general framework for selecting indicators. The framework, designed to transparently include both scientific and policy considerations into the selection and evaluation process, was developed and then utilized in the organization and determination of a preliminary set of indicators. Next, the indicators were assessed against a set of nineteen distinct criteria that describe the model characteristics of an indicator. A literature review was performed for each indicator to determine the extent to which it satisfied each of the evaluation criteria. The result of each literature review was summarized in a numerical matrix, allowing comparison, and demonstrating the extent of scientific reliability. Finally, an approach for ranking indicators was developed to explore the effects of intended purpose on indicator selection. We identified several sets of scientifically valid and policy-relevant indicators that included metrics such as annual-7 day low flow and water system reliability, which are supportive of the EBM approach in the Puget Sound.  相似文献   
86.
In an effort to garner consensus around environmental programs, practitioners have attempted to increase awareness about environmental threats and demonstrate the need for action. Nonetheless, how beliefs about the scope and severity of different types of environmental concerns shape support for management interventions are less clear. Using data from a telephone survey of residents of the Puget Sound region of Washington, we investigate how perceptions of the severity of different coastal environmental problems, along with other social factors, affect attitudes about policy options. We find that self-assessed environmental understanding and views about the seriousness of pollution, habitat loss, and salmon declines are only weakly related. Among survey respondents, women, young people, and those who believe pollution threatens Puget Sound are more likely to support policy measures such as increased enforcement and spending on restoration. Conversely, self-identified Republicans and individuals who view current regulations as ineffective tend to oppose governmental actions aimed at protecting and restoring Puget Sound. Support for one policy measure—tax credits for environmentally-friendly business practices—is not significantly affected by political party affiliation. These findings demonstrate that environmental awareness can influence public support for environmental policy tools. However, the nature of particular management interventions and other social forces can have important mitigating effects and need to be considered by practitioners attempting to develop environment-related social indicators and generate consensus around the need for action to address environmental problems.  相似文献   
87.
The Suzhou Creek Rehabilitation Project (SCRP) is one of the largest water-related environmental rehabilitation schemes ever undertaken in the vicinity of Shanghai, China. This paper details the development and application of a River Environmental Decision Support System (REDSS) for scientific planning and decision-making on the Suzhou Creek project, and illustrates the flexibility of the REDSS framework. We developed the following components: (1) a GIS-based analysis employing Component technology; (2) a "data mart" for multi-dimensional, multi-level, integrated, dynamic, and flexible data querying; and (3) a set of hydrodynamic and water quality models which can simulate complex tidal river networks. In addition, we detail how a water quality assessment model is embedded into the REDSS by employing an Identification Index Method. With the REDSS, all GIS and non-GIS components are integrated seamlessly and data from different sources can be queried simultaneously. This allows for various scenarios to be simulated and analyzed in advance to predict and assess the effects of proposed engineering and management measures. Generated information can thus support effective decisions. All operations of the REDSS can be implemented conveniently through user-friendly interfaces. The function of the REDSS framework is demonstrated through an application to Suzhou Creek. Because the REDSS characteristics are quite general, it may be applied in different geographic regions.  相似文献   
88.
Phillip Drake 《Disasters》2016,40(2):346-364
The Lapindo mudflow is one of the most controversial disasters in Indonesian history. Despite its unique biophysical features, most consider the mudflow a social disaster as scientific conflicts about its main trigger have evolved into legal disputes over accountability and rights. This paper examines this ‘trigger debate’, the stakes of scientific contention and the broader social and natural dynamics that shape the terms of this debate. A Latourian impulse drives this analysis, which aims to improve both understandings of—and responses to—complex disasters. This paper also notes that the stakes of representation extend to constructions of its stakeholders, especially to victims. As socionatural disasters become an increasingly common feature of the contemporary world, from mud volcanoes to extreme weather events caused by global warming, it is more important than ever to understand the dynamics of representing disasters and stakeholders.  相似文献   
89.
Populations of the sponge Dysidea (Lamellodysidea) herbacea, which host the cyanobacterium Oscillatoria spongeliae, vary in their production of polychlorinated peptides. Peptide natural products previously isolated from D. herbacea are often halogenated and include dysidin, dysidinin, and a series of chlorinated diketopiperazines. Strikingly, the distinctive leucine-derived trichloromethyl signature of these compounds is shared only with metabolites of the marine cyanobacterium Lyngbya majuscula, and includes such compounds as barbamide and nordysidinin. Genetic information available for the barbamide biosynthetic gene cluster was used to successfully polymerase chain reaction (PCR) amplify a barB1 homolog (dysB1) from D. herbacea samples collected in Papua New Guinea. Catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH) analysis showed that dysB1 oligonucleotide probes hybridized to sequences in the filamentous cyanobacterial symbiont O. spongeliae. Consistent with this finding, a D. herbacea/O. spongeliae collection devoid of the polychlorinated peptides did not contain the barB1 homologs.Communicated by P.W. Sammarco, Chauvin  相似文献   
90.
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