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91.
Present study was conducted in rapidly growing city Islamabad, and surface soils were collected from three major land cover types viz., built-up, drain side, and green areas. A total of seven physicochemical parameters and 11 metals were determined in surface soils. Factor analysis based on principal component analysis explained total variance of 68.0%, 64.5%, and 60.2% of three land cover types and showed high loadings for major elements (Mg and K) in built-up and green area and Fe in drain side. Top soil pollution index was carried out by using geo-accumulation index and metal pollution index (MPI6). Concentration of major elements (Ca, Mg, Na, K) in surface soils is derived by parent material, whereas concentration of Fe, Ni, Pb, and Zn were mainly related with anthropogenic sources. Geostatistical methods such as kirging identified hotspot areas of metal contamination by Pb, Ni, and Zn in built-up areas influenced mainly by vehicular emissions and waste disposal. The results stresses that land clearing should be avoided to reduce contamination and management of urban soils.  相似文献   
92.
The degradation of monochlorobenzene (MCB) was assessed in a constructed wetland treating MCB contaminated groundwater using a detailed geochemical characterisation, stable isotope composition analysis and in situ microcosm experiments. A correlation between ferrous iron mobilisation, decreasing MCB concentration and enrichment in carbon isotope composition was visible at increasing distance from the inflow point, indicating biodegradation of MCB in the wetland. Additionally, in situ microcosm systems loaded with 13C-labelled MCB were deployed for the first time in sediments to investigate the biotransformation of MCB. Incorporation of 13C-labelled carbon derived from the MCB into bacterial fatty acids substantiated in situ degradation of MCB. The detection of 13C-labelled benzene indicated reductive dehalogenation of MCB. This integrated approach indicated the natural attenuation of the MCB in a wetland system. Further investigations are required to document and optimise the in situ biodegradation of MCB in constructed and natural wetland systems treating contaminated groundwater.  相似文献   
93.
Porencephaly is a rare central nervous system (CNS) abnormality that can be caused by an intraparenchymal destructive process or a developmental defect. Here we report on a prenatal ultrasound diagnosis of complex CNS abnormalities including agenesis of the corpus callosum, agenesis of the cerebellar vermis, bilateral hydrocephaly, and bilateral porencephaly in fetus at 33 weeks' gestation. The diagnosis of familial orofaciodigital syndrome type I (OFD I) was raised after fetal autopsy, clinical examination of the family, and the X-linked dominant inheritance pattern. This is the fourth report of porencephaly in association with OFD I. We discuss the difficulties in genetic counselling since OFD I shows variable expressivity of the phenotypic features. Furthermore, we emphasize the importance of a detailed ultrasound examination after a prenatal diagnosis of porencephaly. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
94.
In many cases in which climate change affects natural resources, impacts are uncertain and adaptation to climate change often involves collective action problems at the local level, which are embedded in multilevel governance regimes. Adaptive management (AM) is an emerging approach to deal with such uncertainty and complexity by promoting multilevel institutions that are robust to change and able to learn. Much of the literature evaluating AM in multilevel governance regimes, however, focuses only on the adherence to certain structural features said to make AM successful, leaving aside the question whether AM actually produces desired outcomes. This paper evaluates AM in multilevel regimes also in terms of the outcomes they produce. To this end, we first apply the Management and Transition Framework (MTF) in order to describe three multilevel regimes in Lesotho. For each regime we then observe whether it adheres to the structure features of AM. Finally, we evaluate the extent to which the outcomes, natural resource management projects, are conducive to Ostrom's (1990) ‘design principles’ for sustainable common-pool resource management. We find that, though no ideal ‘adaptive regime’ is found in Lesotho, the results confirm the AM hypotheses that decentralised decision-making, open information sources, and plurality of user interests lead to improved outcomes. Conversely, elements of the climate regime are found not to be adaptive. Our findings also confirm the appropriateness of AM as a governance approach to climate adaptation.  相似文献   
95.
Environmental Science and Pollution Research - In Senegal, processes employed for recycling e-wastes result in release of so-called heavy metals in the environment. In this study, the metal...  相似文献   
96.
Fungicides are moderately hydrophobic and have been detected in water and sediment, particularly in agricultural watersheds, but typically are not included in routine water quality monitoring efforts. This is despite their widespread use and frequent application to combat fungal pathogens. Although the efficacy of these compounds on fungal pathogens is well documented, little is known about their effects on nontarget fungi. This pilot study, a field survey in southwestern Idaho from April to December 2010 on four streams with varying pesticide inputs (two agricultural and two reference sites), was conducted to assess nontarget impact of fungicides on gut fungi, or trichomycetes. Tissues of larval black flies (Diptera: Simuliidae), hosts of gut fungi, were analyzed for pesticide accumulation. Fungicides were detected in hosts from streams within agricultural watersheds but were not detected in hosts from reference streams. Gut fungi from agricultural sites exhibited decreased percent infestation, density and sporulation within the gut, and black fly tissues had elevated pesticide concentrations. Differences observed between the sites demonstrate a potential effect on this symbiotic system. Future research is needed to parse out the details of the complex biotic and abiotic relationships; however, these preliminary results indicate that impacts to nontarget organisms could have far‐reaching consequences within aquatic ecosystems.  相似文献   
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We investigated the effects of warming on a natural phytoplankton community from the Baltic Sea, based on six mesocosm experiments conducted 2005–2009. We focused on differences in the dynamics of three phytoplankton size groups which are grazed to a variable extent by different zooplankton groups. While small-sized algae were mostly grazer-controlled, light and nutrient availability largely determined the growth of medium- and large-sized algae. Thus, the latter groups dominated at increased light levels. Warming increased mesozooplankton grazing on medium-sized algae, reducing their biomass. The biomass of small-sized algae was not affected by temperature, probably due to an interplay between indirect effects spreading through the food web. Thus, under the higher temperature and lower light levels anticipated for the next decades in the southern Baltic Sea, a higher share of smaller phytoplankton is expected. We conclude that considering the size structure of the phytoplankton community strongly improves the reliability of projections of climate change effects.  相似文献   
100.
Recent theoretical models predict that the relative allocation to advertisement and parental care depends on whether paternal care is necessary for offspring survival: In species with exclusive male care, male investment in attraction is expected to reliably indicate paternal care effort and male phenotypic quality. Previous research, yielding contrasting results, has considered how one trait involved in mate attraction interacts with parental care or a specific aspect of male quality. In the blenny Salaria pavo, we perform a comprehensive analysis of the interplay between overall male attractiveness and male quality, the latter in terms of fertility, condition, and parental care. In this fish, males are larger than females, exhibit two sexually dimorphic traits (head crest and anal glands), and solely care for eggs. We generated a male attractiveness index through principal component analyses of morphological traits and quantified parental effort as the total time spent in egg care. In addition, we analyzed the relationships between specific components of attractiveness and male qualities. In agreement with theory predictions, we found that male overall attractiveness is a reliable indicator of fertility, in terms of sperm number, but is unrelated to body condition and parental care effort, with males able to perform high levels of care regardless of their level of advertisement. However, the relative expression of head crest area appears positively related to sperm number but is traded-off with parental care effort. These findings underline the need, in addressing real patterns, to consider interactions between multiple aspects of male display and quality.  相似文献   
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