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Aerosol constituents (elemental carbon, organic carbon, soluble ions including organic acids, and selected trace metals) were investigated from samples of a field campaign taking place at Bhola Island in the Bay of Bengal (Bangladesh). The campaign took place in the pre-monsoon season (May 2001) using low volume samplers. Carbonaceous material comprised the majority of the analysed components. The average concentrations of EC and OC were 2.8 and 4.6 microg m(-3), respectively. Oxalic acid was the most abundant dicarboxylic acid (average 268 ng m(-3)) followed by malonic and malic acid. The contribution of carboxylic acids-carbon to organic carbon was 2.0%. Average concentrations observed for sulfate and nitrate were 3.7 microg m(-3) and 1.5 microg m(-3). Two different types of aerosol were identified at the rural background site on Bhola Island during southerly synoptic flow by means of trajectory analysis: air masses were transported from the Bay of Bengal to the sampling site in all cases. However, during "Period 1" they experienced longer residence times over the Indian Ocean, while the "Period 2" trajectories came along the Indian coast or passed over the Indian continent. During Period 1 the concentration levels of soluble ions were a factor of 4-6 lower than during Period 2. The concentrations of EC, OC and K differed less than a factor of 1.5 between the two periods. The Period 1 aerosol showed similarities to the haze layers observed during winter-monsoon conditions south of India during the INDOEX experiment. Based on EC/TC and K/EC ratios we find that around 80% of the carbonaceous aerosol from Period 1 in Bhola is from fossil fuel and only around 50% from Period 2. Absolute concentrations of carbonaceous species, soluble ions and trace metals indicate that the background site on Bhola Island is affected by emissions from urbanized regions of Southeast Asia.  相似文献   
3.
The feasibility of including sustainability in LCA for product development   总被引:1,自引:0,他引:1  
The feasibility of combining the concept of sustainability principles and the methodology of Life Cycle Assessment (LCA) is examined. The goal is to achieve an operational tool that incorporates sustainability in product development and strategic planning. While the method outlined has the structure of LCA, it emphasises aspects and parameters often omitted from traditional LCA. The analysis and results can be either qualitative or semi-quantitative. Although a qualitative analysis is less time consuming, it can still highlight the important issues. Qualitative information, which is easily lost in a quantitative analysis, can be emphasised. One of the conclusions is that the method is well suited for screening analysis.  相似文献   
4.
We report a 16-month-old boy with delayed psychomotor development, dysmorphic features, and failure to thrive. He had a mosaic karyotype detected prenatally: mos 46,XY/47,XY,+r(20)/47,XY,+20. After birth, the abnormal cell lines were confirmed in a number of tissues. The small ring chromosome was identified using fluorescence in situ hybridization as derived from chromosome 20. We compared our patient with previously reported cases of mosaic trisomy 20 detected prenatally and associated with an abnormal phenotype. In an attempt to characterize an r(20) syndrome, we also compared our case with two similar reports in the literature.  相似文献   
5.
本文表明农场主之间的联合经营体(partnership arrangements)可能是保障农场经济生存能力和提高效益的途径之一.本文讨论了三种不同协作类型的经验分析,并强调了与协作经营关联的环境改善.在第一个案例中,对牛奶场和种植农场的协作进行了分析,结果表明多样化的提高和轮作具有实质的潜在效益,当协作包括机械时,其潜在效益更高.第二个例子论及生猪育崽和精饲管理的外部综合条件.协作利润源于生物因子和技术因子两方面,诸如提高生长率和增加猪舍的利用率等.最后,本文对一组种植农场协作进行了评估,认为效益的增加主要得益于机械费用的减少和/或来自其它因素的收益,如轮作和管理、营销策略等的改善.  相似文献   
6.
Research on urban insect pollinators is changing views on the biological value and ecological importance of cities. The abundance and diversity of native bee species in urban landscapes that are absent in nearby rural lands evidence the biological value and ecological importance of cities and have implications for biodiversity conservation. Lagging behind this revised image of the city are urban conservation programs that historically have invested in education and outreach rather than programs designed to achieve high‐priority species conservation results. We synthesized research on urban bee species diversity and abundance to determine how urban conservation could be repositioned to better align with new views on the ecological importance of urban landscapes. Due to insect pollinators’ relatively small functional requirements—habitat range, life cycle, and nesting behavior—relative to larger mammals, we argue that pollinators put high‐priority and high‐impact urban conservation within reach. In a rapidly urbanizing world, transforming how environmental managers view the city can improve citizen engagement and contribute to the development of more sustainable urbanization.  相似文献   
7.
Natural steroidal estrogens, such as 17 β-estradiol (E2), as well as antimicrobials such as doxycycline and norfloxacin, are excreted by humans and hence detected in sewage sludge and biosolid. The disposal of human waste products on agricultural land results in estrogens and antibiotics being detected as mixtures in soils. The objective of this study was to examine microbial respiration and E2 mineralization in sewage sludge, biosolid, and soil in the presence and the absence of doxycycline and norfloxacin. The antimicrobials were applied to the media either alone or in combination at total rates of 4 and 40 mg kg?1, with the 4 mg kg?1 rate being an environmentally relevant concentration. The calculated time that half of the applied E2 was mineralized ranged from 294 to 418 days in sewage sludge, from 721 to 869 days in soil, and from 2,258 to 14,146 days in biosolid. E2 mineralization followed first-order and the presence of antimicrobials had no significant effect on mineralization half-lives, except for some antimicrobial applications to the human waste products. At 189 day, total E2 mineralization was significantly greater in sewage sludge (38 ±0.7%) > soil (23 ±0.7%) > biosolid (3 ±0.7%), while total respiration was significantly greater in biosolid (1,258 mg CO2) > sewage sludge (253 mg CO2) ≥ soil (131 mg CO2). Strong sorption of E2 to the organic fraction in biosolid may have resulted in reduced E2 mineralization despite the high microbial activity in this media. Total E2 mineralization at 189 day was not significantly influenced by the presence of doxycycline and/or norfloxacin in the media. Antimicrobial additions also did not significantly influence total respiration in media, except that total CO2 respiration at 189 day was significantly greater for biosolid with 40 mg kg?1 doxycycline added, relative to biosolid without antimicrobials. We conclude that it is unlikely for doxycycline and norfloxacin, or their mixtures, to have a significant effect on E2 mineralization in human waste products and soil. However, the potential for E2 to be persistent in biosolids, with and without the presence of antimicrobials, is posing a challenge for biosolid disposal to agricultural lands.  相似文献   
8.
Cooking fumes contain compounds that may give rise to oxidative stress and mutations when inhaled. The aim of this study was to evaluate if cooking fumes from frying of bacon induce oxidative stress by measurement of urinary 8-oxo-7,8-dihydro-2 deoxyguanosine, a marker of oxidatively damaged DNA. Three non-smoking women fried bacon for 3 h. Urine samples were taken as early morning void at the same time on four days; the morning before frying, the morning after first frying, the morning after three days of frying and one week after first urine sample. 8-Oxo-7,8-dihydro-2 deoxyguanosine, 1-hydroxypyrene and 2-hydroxyphenanthrene, metabolites of polycyclic aromatic hydrocarbons, were measured by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). 8-Oxo-7,8-dihydro-2 deoxyguanosine correlated weakly with concentrations of 1-hydroxypyrene (r = 0.31, p = 0.042), but it did not correlate with 2-hydroxyphenanthrene (r = ?0.074; p = 0.64). Average urinary 8-oxo-7,8-dihydro-2 deoxyguanosine concentrations increased from the day before frying (16.3 ± 4.2 nmol/L) to the third day of frying (26.2 ± 10.2 nmol/L), although not statistically significantly. Our pilot study shows that frying of bacon may result in increased oxidative stress which further emphasises the possible carcinogenic potential of cooking fumes.  相似文献   
9.
Loss of natural forests by forest clearcutting has been identified as a critical conservation challenge worldwide. This study addressed forest fragmentation and loss in the context of the establishment of a functional green infrastructure as a spatiotemporally connected landscape-scale network of habitats enhancing biodiversity, favorable conservation status, and ecosystem services. Through retrospective analysis of satellite images, we assessed a 50- to 60-year spatiotemporal clearcutting impact trajectory on natural and near-natural boreal forests across a sizable and representative region from the Gulf of Bothnia to the Scandinavian Mountain Range in northern Fennoscandia. This period broadly covers the whole forest clearcutting period; thus, our approach and results can be applied to comprehensive impact assessment of industrial forest management. The entire study region covers close to 46,000 km2 of forest-dominated landscape in a late phase of transition from a natural or near-natural to a land-use modified state. We found a substantial loss of intact forest, in particular of large, contiguous areas, a spatial polarization of remaining forest on regional scale where the inland has been more severely affected than the mountain and coastal zones, and a pronounced impact on interior forest core areas. Salient results were a decrease in area of the largest intact forest patch from 225,853 to 68,714 ha in the mountain zone and from 257,715 to 38,668 ha in the foothills zone, a decrease from 75% to 38% intact forest in the inland zones, a decrease in largest patch core area (assessed by considering 100-m patch edge disturbance) from 6114 to 351 ha in the coastal zone, and a geographic imbalance in protected forest with an evident predominance in the mountain zone. These results demonstrate profound disturbance of configuration of the natural forest landscape and disrupted connectivity, which challenges the establishment of functional green infrastructure. Our approach supports the identification of forests for expanded protection and conservation-oriented forest landscape restoration.  相似文献   
10.
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