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251.
Inorganic polyphosphates (PolyP) are simple linear phosphate (PO(4)(3-)) polymers which are produced by a variety of microorganisms. One of their functions is to complex metals resulting in their precipitation. We investigated the interaction of phosphate and low-molecular-weight PolyP (1400-1900Da) with uranyl ion at various pHs. Potentiometric titration of uranyl ion in the presence of phosphate showed two sharp inflection points at pHs 4 and 8 due to uranium hydrolysis reaction and interaction with phosphate. Titration of uranyl ion and PolyP revealed a broad inflection point starting at pH 4 indicating that complexation of U-PolyP occurs over a wide range of pHs with no uranium hydrolysis. EXAFS analysis of the U-HPO(4) complex revealed that an insoluble uranyl phosphate species was formed below pH 6; at higher pH (> or = 8) uranium formed a precipitate consisting of hydroxophosphato species. In contrast, adding uranyl ion to PolyP resulted in formation of U-PolyP complex over the entire pH range studied. At low pH (< or = 6) an insoluble U-PolyP complex having a monodentate coordination of phosphate with uranium was observed. Above pH 6 however, a soluble bidentate complex with phosphate and uranium was predominant. These results show that the complexation and solubility of uranium with PO(4) and PolyP are dependent upon pH.  相似文献   
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Wood resources are often used to support the needs of the local population. In order to protect biodiversity and resources, conservation strategies need to consider what types of wood use have the strongest impacts on forested areas. This study aimed to identify the use categories that put higher pressure on an Atlantic forest region located in the municipality of Igarassu in Pernambuco, northeastern Brazil. To conduct the study, we measured the volume of all wood products in 62 surveyed residences and registered the average replacement time for such products. The fuelwood category was most important locally and accounted for 92% of annual wood consumption. However, the construction category harvests more destructively and concentrates on the consumption of a few wood species. Therefore we recommend the fuelwood category to be the main focus of conservation effforts. In addition, the most important species for construction purposes (e.g., Eschweilera ovata (Cambess.) Miers, Apuleia leiocarpa (Vogel) J.F. Macbr. and Pogonophora schomburgkiana Miers ex Benth) should also be considered as a priority for conservation.  相似文献   
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A Jewish couple of mixed origin was referred for genetic counseling following termination of pregnancy at 18 weeks of gestation due to severe ventriculomegaly with aqueduct stenosis. Trio exome sequencing revealed a loss-of-function heterozygous variant in the SMARCC1 gene inherited from an unaffected mother. The SMARCC1 gene is associated with embryonic neurodevelopmental processes. Recent studies have linked perturbations of the gene with autosomal dominant congenital hydrocephalus, albeit with reduced penetrance. However, these studies were not referenced in the SMARCC1 OMIM record (*601732) and the gene was not considered, at the time, an OMIM morbid gene. Following our case and appeal, SMARCC1 is now considered a susceptibility gene for hydrocephalus. This allowed us to reclassify the variant as likely pathogenic and empowered the couple to make informed reproductive choices.  相似文献   
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Across the Americas, biofuels production systems are diverse due to geographic conditions, historical patterns of land tenure, different land use patterns, government policy frameworks, and relations between the national state and civil society, all of which shape the role that biofuels play in individual nations. Although many national governments throughout the Americas continue to incentivize growth of the biofuels industry, one key challenge for biofuels sustainability has been concern about its social impacts. In this article, we discuss some of the key social issues and tensions related to the recent expansion of biofuels production in Mexico, Colombia, and Brazil. We argue that a process of “simplification” of ecological and cultural diversity has aided the expansion of the biofuels frontier in these countries, but is also undermining their viability. We consider the ability of governments and non-state actors in multi-stakeholder initiatives (MSI) to address social and environmental concerns that affect rural livelihoods as a result of biofuels expansion. We analyze the tensions between global sustainability standards, national level policies for biofuels development, and local level impacts and visions of sustainability. We find that both government and MSI efforts to address sustainability concerns have limited impact, and recommend greater incorporation of local needs and expertise to improve governance.  相似文献   
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The expansion of offshore renewable energy production, such as wind, wave and tidal energy, is likely to lead to conflict between different users of the sea. Two types of spatial decision support tools were developed to support stakeholder workshops. A value mapping tool combines regional attributes with local knowledge. A negotiation support tool uses these value maps to support stakeholders in finding acceptable locations for tidal energy devices. Interactive value mapping proved useful to address deficiencies in data and to create credibility for these maps. The negotiation tool helped stakeholders in balancing objectives of the various stakeholders.  相似文献   
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Environmental Science and Pollution Research - Crack-cocaine is a cocaine by-product widely consumed by general population in developing countries. The drug is low cost and is associated with more...  相似文献   
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Using geographic information system, soil sampling, and statistical analysis to map anthropogenic effects on soil  相似文献   
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Combustion of hydrocarbon fuels with pure oxygen results in a different flue gas composition as combustion with air. Standard CFD spectral gas radiation models for air blown combustion are out of their validity range. The series of three articles provides a common spectral basis for the validation of new developed models. Part B of the series presents spectral measurements in the spectral range of 2.4–5.4 μm of a 70 kW turbulent natural gas flame in air blown combustion and in wet and dry oxyfuel combustion. The experimentally measured intensity spectra were compared with simulated spectra based on measured gas atmospheres. The line-by-line database HITEMP2010 and the two statistical-narrow-band models EM2C and RADCAL were used for the numerical simulation. The measured spectra showed large fluctuations due to turbulence. The up to 75% increased averaged experimental intensity compared to the simulated intensity pointed out the importance of the effect of turbulence-radiation-interaction in combustion simulations.  相似文献   
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