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221.
It is known that radiation can induce a transmissible persistent destabilization of the genome. We have established an in vitro cellular model using HOS cells to investigate whether genomic instability plays a role in depleted uranium (DU)-induced effects. Transmissible genomic instability, manifested in the progeny of cells exposed to ionizing radiation, has been characterized by de novo chromosomal aberrations, gene mutations, and an enhanced death rate. Cell lethality and micronuclei formation were measured at various times after exposure to DU, Ni, or gamma radiation. Following a prompt, concentration-dependent acute response for both endpoints, there was de novo genomic instability in progeny cells. Delayed reproductive death was observed for many generations (36 days, 30 population doublings) following exposure to DU, Ni, or gamma radiation. While DU stimulated delayed production of micronuclei up to 36 days after exposure, levels in cells exposed to gamma-radiation or Ni returned to normal after 12 days. There was also a persistent increase in micronuclei in all clones isolated from cells that had been exposed to nontoxic concentrations of DU. While clones isolated from gamma-irradiated cells (at doses equitoxic to metal exposure) generally demonstrated an increase in micronuclei, most clonal progeny of Ni-exposed cells did not. These studies demonstrate that DU exposure in vitro results in genomic instability manifested as delayed reproductive death and micronuclei formation.  相似文献   
222.
Cores from four Scottish ombrotrophic peat bogs were used to reconstruct the historical record of atmospheric vanadium (V) deposition in Scotland over the last 150 years. The general similarity of V and Pb concentration profile trends in (210)Pb-dated cores from each of the sites strongly suggested that V, like Pb, is essentially immobile in ombrotrophic peat. After allowance via use of the conservative element Ti for the contribution of soil dust V, the deposition of anthropogenic V was found to be greatest (~ 1.3 to 2.0 mg m(-2) y(-1)) in the mid-20(th) century before decreasing to 0.1-0.3 mg m(-2) y(-1) in the early years of the 21(st) century. The latter values were in good agreement with directly measured atmospheric V fluxes at nearby sites, a finding also observed in the case of Pb. The decline in peat-core-derived fluxes for both V and Pb from 1970 to 2004, however, was not as large as the decline in official UK emission estimates for the two metals during this period. This, along with an order of magnitude discrepancy between the anthropogenic V/Pb ratios at the peat core surface and the higher values of the ratio for UK emissions in the early 2000s, suggests that the recently revised UK emissions data for V may perhaps still be overestimated and/or that some previously deposited Pb is being resuspended in the atmosphere.  相似文献   
223.
The management of municipal waste is one of the most emotive local environmental issues in the UK at present and represents a key sustainability “battleground” as local authorities seek to reduce waste arisings and encourage the reuse and recycling of materials among households. Within the literature on household waste management, a broad range of disciplinary perspectives and practical recommendations exist and it is the aim of this paper to step back and take stock of the role of households and communities in resource consumption and waste generation patterns across the UK within recent decades. By exploring the household in this context, trends in consumption and waste generation are outlined in addition to key influencing factors such as lifestyles and well-being, demographics and environment. Finally, key lessons learnt, challenges faced going forward and approaches for developing more sustainable practices at the household, community and national levels are discussed.  相似文献   
224.
Rare and threatened habitats in Europe must be restored and enhanced in accordance with the European Union's Habitats and Species Directive. In the United Kingdom, conservation and expansion objectives for species and habitats are outlined in the Species Action Plans and Habitat Action Plans. Site identification for these measures has to date been ad hoc without consideration of either the existing "stock" of the natural resource or the ability of the surrounding land use to deliver the enhancement (enlargement) of a given habitat. Using a Geographical Information System, we outline a targeting system for creating new woodland in association with existing ancient woodland in the Chiltern Hills Area of Outstanding Natural Beauty. The aim was to create woodland blocks of at least 100 ha, as being of the most benefit to biodiversity. We identified existing patches of woodland between 20 and 50 ha as cores for habitat expansion and classified land use in terms of its suitability and proximity to these core areas for tree planting to meet the targets of the statutory body. Our results suggest that the targeting method employed is a useful tool for habitat restoration.  相似文献   
225.
Books Received     

Publications Received

Books Received  相似文献   
226.
    
Endemic goitre was prevalent in the population of Derbyshire in the UK for many centuries until it declined from the 1930s. A contemporary medical survey showed that endemicity of goitre was particularly higher in the Carboniferous limestone areas of the Derbyshire-Peak District. Unlike classical goitrous areas of the world, where the distribution of goitre has been found to be related to the iodine content in the environment, there is no such relationship reported for the Derbyshire-Peak District area. The present study reviews the presence of endemic goitre in this area with reference to iodine in different environmental media using past and present data. In comparison with the world average values, the iodine contents in the soil and sediment in the Peak District are not deficient, but compared to England, Wales and Scotland averages, these levels are low. As no information on the mobility and bioavailability of iodine of this area is available, a cautious approach is necessary before any assumption is made on the aetiology of endemic goitre. The study also discusses some hypotheses relating to the possible cause of endemic goitre in the limestone areas. Further research needs are suggested depending on the land use and geochemistry of the Peak District to determine the underlying causes of the former endemic goitre in this area.  相似文献   
227.
Post-consumer carpet represents a high volume, high energy content waste stream. As a fuel for co-firing in cement kilns, waste carpet, like waste tires, has potential advantages. Technological challenges to be addressed include assessing potential emissions, in particular NO emissions (from nylon fiber carpets), and optimizing the carpet feed system. This paper addresses the former. Results of pilot-scale rotary kiln experiments demonstrate the potential for using post-consumer waste carpet as a fuel in cement kilns. Continuous feeding of shredded carpet fiber and ground carpet backing, at rates of up to 30% of total energy input, resulted in combustion without transient puffs and with almost no increase in CO and other products of incomplete combustion as compared to kiln firing natural gas only. NO emissions increased with carpet waste co-firing due to the nitrogen content of nylon fiber. In these experiments with shredded fiber and finely ground backing, carpet nitrogen conversion to NO ranged from 3 to 8%. Conversion increased with enhanced mixing of the carpet material and air during combustion. Carpet preparation and feeding method are controlling factors in fuel N conversion.  相似文献   
228.
Knowledge of phosphorus (P) fractions in dung of animals (dairy cattle, deer, sheep) grazing pasture is important for soil fertility and the potential for P transport in runoff and subsequent surface water quality deterioration. We used sequential fractionation and 31P nuclear magnetic resonance (NMR) spectroscopy to determine P forms in fresh and air-dried (to simulate field conditions during grazing) dung. Sheep dung was richest in P (8 g kg(-1)), and cattle dung poorest (5.5 g kg(-1)). Data for sequential fractionation indicated that most P was extractable by water (15-36%) and bicarbonate (36-45%) in fresh dung, and shifted toward recalcitrant, HCl (12-28%), and residual P forms (15-31%) with drying. Organic P concentration in dung was poor (maximum of 15% of total P), probably due to the poor concentration of phytate in pasture. The 31P NMR spectra of NaOH-EDTA extracts supported this by detecting a low concentration of monoesters (9-19% of total P in extracts), of which phytate is a major component. The 31P NMR data also showed that changes in organic P concentration with drying could be due to the degradation of diesters. Data indicate the decreasing bioavailability of dairy cattle, deer, and sheep dung with drying and the need to consider this effect with respect to P returns for soil fertility and the potential for runoff.  相似文献   
229.
A method for estimating long-term crop yield and production potentials for spring wheat in Canada is described. The assessment was made at a map scale of 1:5 000 000, and is based on map units from the Soils of Canada.Potential net biomass and dry matter yield values were computed using procedures adapted from those described by the FAO. Potential values were determined using a form of photosynthesis model which calculates crop photosynthesis response to temperature and radiation averaged over a growing season. Anticipated yields were derived from these values by employing yield-reducing factors related to moisture stress, autumn workday probability and soil constraints. The anticipated (corrected) yield for each map unit was compared to the maximum potential yield obtainable in the country.The results of the procedure are expressed as a quantitative land suitability assessment. Each map unit was classified into one of 6 suitability classes. Areas with anticipated yields of less than 20% of maximum potential were considered as not suitable for production. From this data base, total crop production potentials were computed for the prairie provinces for various land-use allocations.Analysis of the soil and climatic resources indicates that a production level of 50 million tonnes of wheat, or its equivalent in coarse grains and oilseeds, is possible without altering the present land allocation to pasture, forage or specialty crops. Results of the production model estimates, however, suggest that this figure represents the upper limit of the production capability of the available soil and climatic resources for this region.  相似文献   
230.
The Jarche–Levin syndrome (spondylothoracic dysostosis) is a rare autosomal recessive disorder characterized by a short neck, short trunk and a constricted thorax due to multiple rib and vertebral defects; other visceral malformations are occasionally present. Most cases die in infancy due to respiratory failure. In this report we describe two cases in one family from the United Kingdom. Prenatal diagnosis by ultrasound examination during the second trimester was successfully accomplished in the second case.  相似文献   
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