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131.
Fog water samples were collected in the months of December and January during 1998–2000 at Agra, India. The samples were analyzed for pH, major anions (F, Cl, SO4 2−, NO3 , HCOO and CH3COO), major cations (Ca2+, Mg2+, Na+ and K+) and NH4 + using ion chromatography, ICP-AES and spectrophotometer methods, respectively. pH of fog water samples ranged between 7.0 and 7.6 with a volume weighted mean of 7.2, indicating its alkaline characteristic. NH4 + contributed 40%, SO4 2− and NO3 accounted for 28%, while Ca2+, Mg2+, Na+ and K+ accounted for 16% of the total ionic concentration. The ratios of Mg2+/Ca2+ and Na+/Ca2+ in fog water indicates that 50–75% of fog water samples correspond to the respective ratios in local soil. Significant correlation between Ca2+, Mg2+, Na+ and K+ suggests their soil origin. The order of neutralization, NH4 + (1.4) > Ca2+ (0.28) > Mg2+ (0.12), indicates that NH4 + is the major neutralizing species. Fog water and atmospheric alkalinity were also computed and were found to be 873 and 903 neqm−3, respectively. Both of these values are higher than values reported from temperate sites and thus indicate that at the present level of pollutants, there is no risk of acid fog problem. The study also shows that the alkaline nature of fog water is due to dissolution of ammonia gas and partly due to interaction of fog water with soil derived aerosols.  相似文献   
132.
The analysis of the low-frequency conductivity spectra of the clay-water mixtures is presented. The frequency dependence of the conductivity is shown to follow the power-law with the exponent n=0.67 before reaching the frequency-independent part. When scaled with the value of the frequency-independent part of the spectrum the conductivity spectra for samples at different water content values are shown to fit to a single master curve. It is argued that the observed conductivity dispersion is a consequence of the anomalously diffusing ions in the clay-water system. The fractional Langevin equation is then used to describe the stochastic dynamics of the single ion. The results indicate that the experimentally observed dielectric properties originate in anomalous ion transport in clay-water system characterized with time-dependent diffusion coefficient.  相似文献   
133.
Imidacloprid (IMI) is at the moment the insecticide with the world's fastest growing sales and is considered possible replacement for the widely used organophosphorus pesticide, diazinon, which is subject to phased revocation in many countries. In this study, biochemical, reproductive and survival parameters of the water flea (Daphnia magna) after chronic exposure to IMI, its commercial liquid formulation Confidor SL 200 and diazinon are presented and compared. According to the lowest observed effect concentrations, diazinon is more toxic to the reproduction of D. magna than IMI and Confidor SL 200, which exert similar toxicity. The same was observed for the survival, except that Confidor SL 200 is more toxic than IMI. In polluted aquatic environments, the actual levels of diazinon are potentially chronically hazardous to the reproduction of D. magna (risk quotient >1). According to very few measured environmental levels of IMI, the latter is not expected to be chronically hazardous, unless it is accidentally spilled in a small pond. In such case, the predicted concentrations of IMI would present a potential chronic risk to D. magna, and a potential acute risk to other aquatic invertebrates. In the future, higher environmental levels of IMI are expected due to its increasing use and physico-chemical properties. The literature survey summarized in this work suggests that further ecotoxicological studies with a broader spectrum of aquatic organisms are needed before IMI is classified as safer than currently applied pesticides.  相似文献   
134.
Human society has experienced, and will continue to experience, extensive loss and damage from worsening anthropogenic climate change. Despite our natural tendencies to categorise and organise, it can be unhelpful to delineate clean boundaries and linear understandings for complex and messy concepts such as loss and damage. Drawing on the perspectives of 42 local and regional Pacific Islander stakeholders, an underexplored resource for understanding loss and damage, we explore the complexity and interconnectedness of non-economic loss and damage (NELD). According to participants, Pacific Islander worldviews, knowledge systems and cosmologies often make it difficult to separate and evaluate NELD independently, challenging the nomenclature of NELD categories developed through international mechanisms. Instead, NELD understandings are often centred on the interdependencies between losses, including the cascading flow-on effects that can occur and the nature of some losses as risk multipliers (i.e. one loss creating the risk for further losses). Most notably, losses to biodiversity, ecosystem services and land are critically linked to, and have cascading effects on, livelihoods, knowledge, ways of life, wellbeing, and culture and heritage. We argue that loss and damage is not always absolute, and that there are NELD that are arguably reparable. Concerning, however, is that biodiversity loss, as a risk multiplier, was considered the least reparable by participants. We put forward that NELD understandings must consider interconnectivity, and that biodiversity and ecosystem conservation and restoration must be the focus for interventions to prevent irreparable and cascading losses from climate change in the Pacific Islands.  相似文献   
135.
The purpose of this study was to assess the oxidative biomarkers responses, antioxidant potential and metal accumulation tendency of weed plants collected from the control and metal-contaminated site. The metal contamination was found to be higher in soil and plant parts collected from contaminated site and the most serious problem seemed to be metal elevations above than the safe limit for Cd, Pb and Ni in the aerial parts of weed plants. There were variations in metal accumulation in different weed plants that was justified by principal component analysis. The enzymatic and non-enzymatic antioxidants were found to be higher in plant parts collected from contaminated site. Based upon metal accumulation tendency, weed plants showed a translocation ratio (>1) that reflect their potential for metal remediation. The values of metal pollution index also showed higher tendency of metal accumulation in weed plants, particularly in Solanum nigrum, Euphorbia hirta, Amaranthus hybridus and Xanthium strumarium, and they can also flourish at contaminated sites with more production of antioxidants. So, it suggests that studied weed species can be classified as phytoremediation plants and can be used as eco-friendly and economically feasible technique for restoring the land contaminated with toxic metals.  相似文献   
136.
Selenium status in food grains of northern districts of India   总被引:2,自引:0,他引:2  
The selenium status in the food grains of the agricultural lands of northern parts of India was estimated by using the HG-AAS technique. The areas where lesser rains were received or less irrigation water was available in northern Indian states viz. Rajasthan and southern parts of the Haryana had higher selenium levels in food grains. Punjab, Himachal Pradesh and northern parts of the Haryana states had normal levels of selenium in their food grains, except for slightly lower selenium levels in a few areas that were affected by floods along the river Yamuna.  相似文献   
137.
Abstract: Runoff from urban catchments depends largely on the amount of impervious surface and the connectivity of these surfaces to the storm sewer drainage system. In residential areas, pervious lawns can be used to help manage stormwater runoff by intercepting and infiltrating runoff from impervious surfaces. The goal of this research was to develop and evaluate a simple method for estimating the reduction in stormwater runoff that results when runoff from an impervious surface (e.g., rooftop) is directed onto a pervious surface (e.g., lawn). Fifty‐two stormwater runoff reduction tests were conducted on six residential lawns in Madison, Wisconsin during the summer of 2004. An infiltration‐loss model that requires inputs of steady‐state infiltration rate, abstraction (defined here as surface storage, vegetation interception and cumulative total infiltration minus steady‐state infiltration during the period prior to steady‐state), and inundated area was evaluated using experimental data. The most accurate results were obtained using the observed steady‐state infiltration rates and inundated areas for each test, combined with a constant abstraction for all tests [root mean squared (RMS) difference = 1.0 cm]. A second case utilized lawn‐averaged steady‐state infiltration rates, a regression estimate of inundated area based on flow‐path length, and lawn‐specific abstractions based on infiltration rate (RMS difference = 2.2 cm). In practice, infiltration rates will likely be determined using double‐ring infiltration measurements (RMS difference = 3.1 cm) or soil texture (RMS difference = 5.7 cm). A generalized form of the model is presented and used to estimate annual stormwater runoff volume reductions for Madison. Results indicate the usefulness of urban lawns as a stormwater management practice and could be used to improve urban runoff models that incorporate indirectly connected impervious areas.  相似文献   
138.
Habitat loss and fragmentation are causing widespread population declines, but identifying how and when to intervene remains challenging. Predicting where extirpations are likely to occur and implementing management actions before losses result may be more cost‐effective than trying to reestablish lost populations. Early indicators of pressure on populations could be used to make such predictions. Previous work conducted in 2009 and 2010 identified that the presence of Eastern Yellow Robins (Eopsaltria australis) in 42 sites in a fragmented region of eastern Australia was unrelated to woodland extent within 500 m of a site, but the robins’ heterophil:lymphocyte (H:L) ratios (an indicator of chronic stress) were elevated at sites with low levels of surrounding woodland. We resurveyed these 42 sites in 2013 and 2014 for robin presence to determine whether the H:L ratios obtained in 2009 and 2010 predicted the locations of extirpations and whether the previous pattern in H:L ratios was an early sign that woodland extent would become an important predictor of occupancy. We also surveyed for robins at 43 additional sites to determine whether current occupancy could be better predicted by landscape context at a larger scale, relevant to dispersal movements. At the original 42 sites, H:L ratios and extirpations were not related, although only 4 extirpations were observed. Woodland extent within 500 m had become a strong predictor of occupancy. Taken together, these results provide mixed evidence as to whether patterns of individual condition can reveal habitat relationships that become evident as local shifts in occupancy occur but that are not revealed by a single snapshot of species distribution. Across all 85 sites, woodland extent at scales relevant to dispersal (5 km) was not related to occurrence. We recommend that conservation actions focus on regenerating areas of habitat large enough to support robin territories rather than increasing connectivity within the landscape.  相似文献   
139.
The authors of this paper report on the changing character of household waste, in the Czech Republic between 1999 and 2009 in households differentiated by their heating methods. The data presented are the result of two projects, financed by the Czech Ministry of Environment, which were undertaken during this time period with the aim of focusing on the waste characterisation and complete analysis of the physicochemical properties of the household waste. In the Czech Republic, the composition of household waste varies significantly between different types of households based on the methods of home heating employed. For the purposes of these studies, the types of homes were divided into three categories – urban, mixed and rural. Some of the biggest differences were found in the quantities of certain subsample categories, especially fine residue (matter smaller than 20 mm), between urban households with central heating and rural households that primarily employ solid fuel such coal or wood. The use of these solid fuels increases the fraction of the finer categories because of the higher presence of ash. Heating values of the residual household waste from the three categories varied very significantly, ranging from 6.8 MJ/kg to 14.2 MJ/kg in 1999 and from 6.8 MJ/kg to 10.5 MJ/kg in 2009 depending on the type of household and season. The same factors affect moisture of residual household waste which varied from 23.2% to 33.3%. The chemical parameters also varied significantly, especially in the quantities of Tl, As, Cr, Zn, Fe and Mn, which were higher in rural households. Because knowledge about the properties of household waste, as well as its physicochemical characteristics, is very important not only for future waste management, but also for the prediction of the behaviour and influence of the waste on the environment as the country continues to streamline its legislation to the European Union’s solid waste mandates, the results of these studies were employed by the Czech Ministry of Environment to optimise the national waste management strategy.  相似文献   
140.
The unsustainable trade in wildlife is a key threat to Earth's biodiversity. Efforts to mitigate this threat have traditionally focused on regulation and enforcement, and there is a growing interest in campaigns to reduce consumer demand for wildlife products. We aimed to characterize these behavior-change campaigns and the evidence of their impacts. We searched peer-reviewed and grey literature repositories and over 200 institutional websites to retrieve information on demand-reduction campaigns. We found 236 campaigns, mainly in the grey literature. Since the 1970s, the number of campaigns increased, although for over 15% a start date could not be found. Asia was the primary focus, although at the national level the United States was where most campaigns took place. Campaigns most often focused on a single species of mammal; other vertebrates groups, with the exception of sharks, received limited attention. Many campaigns focused on broad themes, such as the wildlife trade in general or seafood. Thirty-seven percent of campaigns reported some information on their inputs, 98% on strategies, 70% on outputs, 37% on outcomes (i.e., changes in the target audience), and 9% on impacts (i.e., biological changes or threat reduction). Information on outcomes and impacts was largely anecdotal or based on research designs that are at a high risk of bias, such as pre- and postcampaign comparisons. It was unclear whether demand-reduction campaigns had direct behavioral or biological impacts. The lack of robust impact evaluation made it difficult to draw insights to inform future efforts, a crucial part of effectively addressing complex issues, such as the wildlife trade. If demand-reduction campaigns are to become a cornerstone of the efforts to mitigate the unsustainable trade in wildlife, conservationists need to adopt more rigorous impact evaluation and a more collaborative approach that fosters the sharing of data and insights.  相似文献   
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