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1.
Environmental Science and Pollution Research - This work is focused on the design and preparation of polymer inclusion membranes (PIMs) for potential applications for stannous cation sequestration...  相似文献   
2.
Conservation Genetics at the Species Boundary   总被引:13,自引:0,他引:13  
Abstract: Conservation genetics has expanded its purview such that molecular techniques are now used routinely to prioritize populations for listing and protection and infer their historical relationships in addition to addressing more traditional questions of heterozygosity and inbreeding depression. Failure to specify whether molecular data are being used for diagnosis-related questions or for population viability questions, however, can lead either to misinterpretation of character data as adaptive information or to misinterpretation of frequency or distance data as diagnostic or historical information. Each of these misinterpretations will confound conservation programs. The character-based approach to delimiting phylogenetic species is both operationally and logically superior to "diagnostic" methods that involve distance- or frequency-based routines, which are unstable over time. Tree-based criteria for the diagnosis of conservation "units" are also inappropriate because they can depend on patterns inferred without reference to diagnostic characters. Intraspecific studies, conservation-related or otherwise, that adopt terminology and methods designed to infer nested hierarchic relationships confuse diagnosis with historical inferences by treating diagnoses as outcomes rather than as precursors to phylogeny reconstruction. A character-based diagnostic approach recognizes the analytical dichotomy between species hierarchies and population statistics and provides a framework for the understanding of each. No species concept, however, should be viewed as an absolute criterion for protecting populations, but as part of a framework from within which identification of protection and management goals can be achieved effectively and defensibly.  相似文献   
3.
Quantifying trace gas emissions and the influence of surface exchange processes on the atmosphere is a necessary step towards the control of global greenhouse gas emissions and reliability of air quality models. This paper proposes a procedure based on the mass balance method and implemented on highly resolved aircraft data. It allows one to estimate surface exchanges on areas of several km2 and heterogeneous features exploiting the characteristics of convective boundary layer during steady state conditions that permit the estimation of emission/absorption terms as functions of advective fluxes only. A nonparametric approach is adopted and the fluxes on the surface of a virtual box surrounding the area of interest are reconstructed on the basis of scalar densities and wind vectors using Shepard functions. Two different techniques are also proposed to face lack of data on the top surface of the box. The method has been applied to experimental data coming from measurement campaigns on two different sites. It provides realistic estimates of the CO2 emission/absorption in the considered areas that are in good agreement with CO2 fluxes evaluated by Airborne Eddy Covariance and confirm the suitability of the proposed approach for the assessment of turbulent exchange of trace gases by composite landscapes. Uncertainties on the estimated emissions due to both propagation of the experimental error and interpolation have been quantified by bootstrap analysis as 6%.  相似文献   
4.
Environmental Science and Pollution Research - Bisphenol A (BPA) is a plasticizer used widely in many industrial products and is now well established as an endocrine-disrupting chemical (EDC). BPA...  相似文献   
5.
Two drinking water production plants located in North Italy, collecting water from the River Po (Plants 1 and 2) were chosen for this study. Water samples were collected before and after the disinfection process and at two points along the piping system. Water samples were concentrated by the solid-phase extraction system and injected intraperitoneally into specimens of Cyprinus carpio. The concentration of water samples was 3 l/equiv. In order to assess the effects of the water samples on carp liver, total glutathione and glutathione-dependent enzymes, such as glutathione S-transferase, glutathione peroxidase, glutathione reductase and glyoxalase I, were measured following this treatment for 6 days at two experimental times (3 and 6 days). Both water plant-treated carp showed a general increase of the enzymatic activities of glutathione S-transferase, and glutathione reductase which might be employed as potential biomarkers of oxidative stress induced by disinfected river water. Plant 1-treated carp showed higher glyoxalase I and glutathione levels and lower glutathione peroxidase activity. A depleted level of total glutathione and of glyoxalase I for specimens of water plant 2 (for both experimental times), without correlation with the distances in the pipeline, suggests that river plant water can also lead to potentially adverse effects on selected biochemical parameters in C. carpio.  相似文献   
6.
Dörr AJ  Pacini N  Abete MC  Prearo M  Elia AC 《Chemosphere》2008,73(7):1090-1095
Many diets employed in aquaculture are enriched with selenium to improve the diet quality and its conservation. The aim of the study was to investigate the effects of a diet enriched in selenium (1.21 mg kg(-1)) on the antioxidant response of Procambarus clarkii (Girard, 1852). Crayfish fed a diet with lower selenium content (0.30 mg kg(-1)) were the control. Selenium accumulation, enzymatic activities, and total glutathione were evaluated in hepatopancreas of adults of both sexes fed with both diets for 50 days at two experimental times (T(30), T(50) days). Treated females exhibited the highest selenium bioaccumulation during both experimental times, while treated males displayed the highest selenium concentration after 30 days, compared to control crayfish. A sex-related difference was found for the response of the analyzed enzymes in the selenium diet-treated specimens. In fact, superoxide dismutase, glutathione peroxidase and glyoxalase I activities in males were more sensitive compared with females, showing depleted activities in both experimental times. Catalase activity was induced in females (T(50)), while glutathione S-transferase activity was the highest in treated females and the lowest in treated males, compared with own controls. Only glutathione reductase activity and glutathione content showed the same trend in both sexes, which were both lowered in treated specimens, when compared with control crayfish. This result might be due to the effect of selenium toxicity on this freshwater species. Males and females of P. clarkii showed a different susceptibility to the prooxidant effects in a Se-enriched diet.  相似文献   
7.

Background  

The impact of shipping emissions on urban agglomerations close to major ports and vessel routes is probably one of the lesser understood aspects of anthropogenic air pollution. Little research has been done providing a satisfactory comprehension of the relationship between primary pollutant emissions, secondary aerosols formation and resulting air quality.  相似文献   
8.
Environmental Science and Pollution Research - Thermo-mineral springs are widely spread over the volcanic areas of Salerno, a city in southern Italy. Although the water of thermal structures...  相似文献   
9.
Environmental Science and Pollution Research - The increased titanium dioxide nanoparticles (TiO2-NPs) spread and their interaction with organic and inorganic pollutants arouses concern for the...  相似文献   
10.
The genus Nyctiphanes (Malacostraca, Euphausiacea) comprises four neritic species that display antitropical geographic distribution in the Pacific (N. simplex and N. australis) and Atlantic (N. couchii and N. capensis) Oceans. We studied the origin of this distribution applying methods for phylogenetic reconstruction and molecular dating of nodes using a Bayesian MCMC analysis and the DNA sequence information contained in mtDNA 16S rDNA and cytochrome oxidase (COI). We tested hypotheses of vicariance by contrasting the time estimates of cladogenesis with the onset of the major barriers to ocean circulation. It was estimated that Nyctiphanes originated in the Pacific Ocean during the Miocene, with a lower limit of 18 miilion years ago (Mya). An Atlantic–Pacific cladogenic event (95% HPD 3.2–9.6) took place after the closure of the Tethyan Sea, suggesting that dispersal occurred from the Indo-Pacific, most likely via southern Africa. Similarly, the antitropical distribution pattern observed in the eastern Atlantic Ocean likely resulted from recent Pliocene–Pleistocene (95% HPD 1.0–4.97) northward dispersal from the southern hemisphere. Our results imply that dispersal appears to have had a significant role to play in the evolution of this group. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
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