Lysosomal membrane stability, lipofuscin (LF), malondialdehyde (MDA), neutral lipid (NL) levels, as well as halogenated organic compounds (HOCs), Cr, Cd, Pb and Fe concentrations were analyzed in liver of black-legged kittiwake (BK), herring gull (HG), and northern fulmar (NF) chicks. There were significant species differences in the levels of NL, LF and lysosomal membrane stability. These parameters were not associated with the respective HOC concentrations. LF accumulation was associated with increasing Cr, Cd and Pb concentrations. HG presented the lowest lysosomal membrane stability and the highest.LF and NL levels, which indicated impaired lysosomes in HG compared to NF and BK. Lipid peroxidation was associated with HOC and Fe2+ levels. Specific HOCs showed positive and significant correlations with MDA levels in HG. The study indicates that contaminant exposure can affect lysosomal and lipid associated parameters in seabird chicks even at low exposure levels. These parameters may be suitable markers of contaminant induced stress in arctic seabirds. 相似文献
A “No Mix” sanitation system was installed in a dormitory at the University of CanTho in South Vietnam, with the objective of recycling nutrients from source separated wastewater streams. This paper presents the “Yellow Water” treatment plant and its efficiency in recovering phosphorus and nitrogen from human urine. The pilot plant achieved phosphorus removal efficiencies of 98% with both diluted and undiluted urine. Phosphorus was recovered in the form of struvite, a solid mineral fertilizer with heavy metal concentrations being below the German Fertilizer Regulation's threshold limits. About 110 g of struvite could be generated after one treatment cycle, during which 50 L of urine were processed. Nitrogen removal by air stripping showed best results when circulating the urine for 3 h through the stripping column at a high flow rate (80 L/h). With these settings, more than 90% of the nitrogen could be removed from the urine, and virtually 100% of this nitrogen could be recovered in the form of liquid ammonium sulfate. In the future, treatment costs could be further reduced by making use of the solar energy that is available during daytime in South Vietnam. 相似文献
The layered sequence from Niagara Icefalls (northern Victoria Land, Antarctica) is related to the Cambrian-Early Ordovician
Ross Orogeny. The sequence consists of dunites, harzburgites, orthopyroxenites, melagabbronorites and gabbronorites of cumulus
origin. The Mg# of olivine, spinel, orthopyroxene and clinopyroxene from these rocks yields positive correlations, thus indicating
formation from melts that mainly evolved through fractional crystallisation. The following fractionation sequence was identified:
olivine (up to 94 mol% forsterite) + Cr-rich spinel → olivine + orthopyroxene ± spinel → orthopyroxene → orthopyroxene + anorthite-rich
plagioclase ± clinopyroxene. Clinopyroxenes retain the peculiar trace element signature of boninite melts, such as extremely
low concentrations of HREE and HFSE, and LILE enrichment over REE and HFSE. U–Pb isotope data on zircons separated from a
gabbronorite have allowed us to constrain the age of emplacement of the Niagara Icefalls sequence at ∼514 Ma. The occurrence
of inherited zircons dated at ∼538 Ma indicates that the boninitic melts experienced, at least locally, crustal contamination.
The Niagara Icefalls sequence can be related to a regional scale magmatic event that affected the eastern margin of the Gondwana
supercontinent in the Middle Cambrian. We propose that the formation of the sequence was associated with the development of
an embryonic back-arc basin in an active continental margin.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
Current knowledge of the basic principles underlying the design of Fe0 beds is weak. The volumetric expansive nature of iron corrosion was identified as the major factor determining the sustainability of Fe0 beds. This work attempts to systematically verify developed concepts. Pumice and sand were admixed to 200 g of Fe0 in column studies (50:50 volumetric proportion). Reference systems containing 100% of each material have been also investigated. The mean grain size of the used materials (in mm) were 0.28 (sand), 0.30 (pumice), and 0.50 (Fe0). The five studied systems were characterized (i) by the time dependent evolution of their hydraulic conductivity (permeability) and (ii) for their efficiency for aqueous removal of CuII, NiII, and ZnII (about 0.3 mM of each). Results showed unequivocally that (i) quantitative contaminant removal was coupled to the presence of Fe0, (ii) additive admixture lengthened the service life of Fe0 beds, and (iii) pumice was the best admixing agent for sustaining permeability while the Fe0/sand column was the most efficient for contaminant removal. The evolution of the permeability was well‐fitted by the approach that the inflowing solution contained dissolved O2. The achieved results are regarded as starting point for a systematic research to optimize/support Fe0 filter design. 相似文献
Bulletin of Earthquake Engineering - The paper presents the comparison of the results of non-linear static analyses performed with different software based on the equivalent frame (EF) modelling... 相似文献
In the Mediterranean region, herbivory appears to be a factor controlling the production of the endemic species Posidonia oceanica, which is mainly due to two main macroherbivores: the sea urchin Paracentrotus lividus, and the sparid fish Sarpa salpa. In this context the present study is a contribution in clarifying herbivory on P. oceanica by testing: 1) whether the abundance of grazing marks of the two herbivores is variable across different spatial scales, 2) whether spatial variation of P. lividus grazing marks and its density is consistent, 3) whether there is a dependence of the number of P. lividus grazing marks on its density, 4) whether the grazing of both macroherbivores, P. lividus and S. salpa, involves the entire leaf length, and 5) whether there is a dependence of the number of P. lividus grazing marks on the number of S. salpa grazing bites. 相似文献
An ecotoxicological protocol with caged mussels, Mytilus galloprovincialis, was developed to evaluate the potential impact of an offshore gas platform in the central Adriatic Sea. Reference organisms were collected on a seasonal basis from an unpolluted site and transplanted for four weeks in both the sampling area and to the investigated platform. Chemical analyses of trace metals in mussel tissues were integrated with a multi-biomarker approach for the early detection of biological responses at several cellular targets. Induction of metallothioneins, peroxisomal proliferation and activity of acetylcholinesterase were measured as markers for specific classes of chemicals. Special attention was given to oxyradical metabolism and appearance of oxidative-mediated toxicity to reveal a more general onset of cellular disturbance. In addition to individual antioxidants (superoxide dismutase, catalase, glutathione S-transferases, glutathione reductase, Se-dependent and Se-independent glutathione peroxidases, and levels of total glutathione), the total oxyradical scavenging capacity (TOSC) allowed a quantification of the overall capability to neutralize specific forms of intracellular reactive oxygen species (ROS; i.e. peroxyl and hydroxyl radicals). Cellular damages were evaluated as lysosomal destabilization (membrane stability, accumulation of lipofuscin and neutral lipids), lipid peroxidation products (malondialdehyde) and DNA integrity (strand breaks and micronuclei); the air survival test was finally applied to evaluate the overall physiological condition of mussels. Concentration of trace metals (As, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn) revealed only limited variations in transplanted mussels during various experimental periods and such changes appeared partly related to natural fluctuations. Among biological responses, variations of antioxidants and lysosomal stability were confirmed as sensitive early warning signals for biological disturbance of both natural and anthropogenic origin. The presented protocol with caged mussels allowed marked biological effects caused by the investigated platform to be excluded, and represented a useful approach that is easy to extend for monitoring the impact of offshore activities in the Adriatic sea. 相似文献
In engineering practice, the liquefaction potential of a sandy soil is usually evaluated with a semi-empirical, stress-based approach computing a factor of safety in free field conditions, defined as the ratio between the liquefaction resistance (capacity) and the seismic demand. By so doing, an estimate of liquefaction potential is obtained, but nothing is known on the pore pressure increments (often expressed in the form of normalized pore pressure ratio ru) generated by the seismic action when the safety factor is higher than 1. Even though ru can be estimated using complex numerical analyses, it would be extremely useful to have a simplified procedure to estimate them consistent with the stress-based approach adopted to check the safety conditions. This paper proposes such a procedure with reference to both saturated and unsaturated soils, considering the latter as soils for which partial saturation has been artificially generated with some ground improvement technology to increase cyclic strength and thus tackle liquefaction risk. A simple relationship between the liquefaction free field safety factor FS, and ru(Sr) is introduced, that generalizes a previous expression proposed by Chiaradonna and Flora (Geotech Lett, 2020. https://doi.org/10.1680/jgele.19.00032) for saturated soils. The new procedure has been successfully verified against some experimental data, coming from laboratory constant amplitude cyclic tests and from centrifuge tests with irregular acceleration time histories for soils having different gradings and densities.