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1.
P. E. O'Sullivan 《Hydrobiologia》1993,251(1-3):351-361
In the period since 1945, Slapton Ley, a small, coastal lake in Southwest England, has been eutrophccated by nutrient inputs generated both by the intensification of agriculture, and the discharge of sewage effluent. Two simple models have been used to identify the main sources of catchment outputs, and to evaluate historical changes in land use, and their likely effect on lake trophic status.Restoration strategies may also be evaluated using the same models. They suggest that in order to reduce loads upon the Ley to within OECD permissible limits, not only will all sewage and phosphate detergent inputs need to be prevented, but also losses from agricultural land must be reduced. This could take the form of the zoning of the catchment so that riparian zones are used, not as at present, for the grazing of livestock, but are converted to woodland, and more particularly eg to buffer strips sensu Mander (1985, 1992).This policy, if implemented comprehensively, would reduce external phosphorus loads to within permissible limits. Eventually, however, some kind of internal control, such as manipulation of the fish populations, may also have to be attempted, in order to remove the memory of five decades of eutrophication.  相似文献   

2.
G. Horne  A.H. Fielding 《Bird Study》2013,60(3):229-236
Capsule Since pesticide controls, it has expanded from a pre-pesticide baseline of 41 pairs to over 100 pairs.

Aims To describe the population's pattern of recovery and identify constraints on its annual productivity.

Methods Occupancy and productivity data were collected from all known and new ranges in Cumbria, UK. Statistical methods were employed to describe temporal and spatial patterns. Possible effects of weather were investigated using meteorological data.

Results The population recovered from eight pairs, with birds preferentially recolonizing 41 traditional ranges. The highest occupancy levels were 100 ranges in 1997 and 1998. Many new ranges were in peripheral and atypical locations, although some resulted from the splitting of traditional ones. The central core now has the highest recorded density (> 9 pairs per 100 km2). As occupied ranges increased, the mean nearest neighbour distance declined to an asymptote (approximately 3.5 km). Simultaneously, maximum values were observed for the percentages of known and occupied ranges in which eggs were laid. The mean number fledged by occupied ranges peaked in the early 1990s. New ranges seem to be more susceptible to the effects of May rainfall but overall there was little evidence that new and traditional ranges differ in productivity. Persecution has continued, with over 10% of examined ranges experiencing intentional disturbance in the worst years.

Conclusion The recovery of the Cumbrian population seems to be related to two processes: (1) greater productivity and survival forcing birds to occupy more peripheral and atypical sites; (2) a very high density in the central core possibly due to increased food supply resulting from the channelling of prey through its valley systems.  相似文献   

3.
A small, non-biomineralized, macrophagous arthropod with chelicerate affinities, Offacolus kingi gen. et sp. nov., from the Silurian (Wenlock Series) of Herefordshire, UK, is described. The dorsal exoskeleton comprises an arch-like cephalic shield, a thorax of three free tergites and a triangular posterior tagma of five fused tergites, the last with a stout postero-dorsally directed medial spine. Seven pairs of appendages beneath the cephalic shield surround a postero-medially sited oral cavity on the ventral surface of the head. Appendages I and, probably II are uniramous and project antero-ventrally; I was sensory and II sensory and/or ambulatory. Appendages III-VI are biramous, each with an antero-ventrally projecting ramus and a robust, highly geniculate, horizontally oriented ramus that projects through an anterior gape. The former rami were ambulatory and the latter have spinose terminal podomeres and functioned as a unit for trapping food and transferring it towards the oral cavity. Appendage VII, which is probably uniramous, is posteroventrally directed and flap like. Each tergite of the thorax and posterior tagma covers at least a pair (probably two pairs) of probably biramous appendages with each ramus flap like and setose.  相似文献   

4.

Background

Nutrient loadings from its catchment upon The Fleet, a highly valuable coastal lagoon in Southern England, were hindcast for the period AD 1866–2004, using a catchment model, export coefficients, and historical data on land use changes, livestock numbers, and human population. Agriculture was the main nutrient source throughout, other inputs representing minor contributions. Permanent pasture was historically the main land use, with temporary grassland and cereals increasing during the mid-20th century. Sheep, the main 19th century livestock, were replaced by cattle during the 1930s.

Results

Total nitrogen loadings rose from ca 41 t yr-1 during the late 19th century to 49–54 t yr-1 for the mid-20th, increasing to 98 t yr-1 by 1986. Current values are ca 77 t yr-1. Total phosphorus loads increased from ca 0.75 t yr-1 for the late 19th century to ca 1.6 t yr-1 for the mid-20th, reached ca 2.2 t yr-1 in 1986, and are now ca 1.5 t yr-1. Loadings rose most rapidly between 1946 and 1988, owing to increased use of inorganic fertilisers, and rising sheep and cattle numbers. Livestock were the main nutrient source throughout, but inputs from inorganic fertilisers increased after 1946, peaking in 1986. Sewage treatment works and other sources contribute little nitrogen, but ca 35% of total phosphorus. Abbotsbury Swannery, an ancient Mute Swan community, provides ca 0.5% of total nitrogen, and ca 5% of total phosphorus inputs.

Conclusion

The Fleet has been grossly overloaded with nitrogen since 1866, climaxing during the 1980s. Total phosphorus inputs lay below 'permissible' limits until the 1980s, exceeding them in inner, less tidal parts of the lagoon, during the 1940s. Loadings on Abbotsbury Bay exceeded 'permissible' limits by the 1860s, becoming 'dangerous' during the mid-20th century. Phosphorus stripping at point sources will not significantly reduce loadings to all parts of the lagoon. Installation of 5 m buffer strips throughout the catchment and shoreline will marginally affect nitrogen loadings, but will reduce phosphorus inputs to the West Fleet below 'permissible' limits. Only a combination of measures will significantly affect Abbotsbury Bay, where, without effluent diversion, loadings will remain beyond 'permissible'.  相似文献   

5.

Aim

Investigate the cost and effects of a single-pill versus two- or three pill first-line antiretroviral combinations in reducing viral load, increasing CD4 counts, and first-line failure rate associated with respective regimens at 6 and 12 months.

Methods

Patients on first-line TDF+3TC+EFV, TDF+FTC+EFV, Truvada®+EFV or Atripla® between 1996–2008 were identified and viral load and CD4 counts measured at baseline, six and twelve months respectively. Factors that independently predicted treatment failure at six and twelve months were derived using multivariate Cox''s proportional hazard regression analyses. Use and cost of hospital services were calculated at six and twelve months respectively.

Results

All regimens reduced viral load to below the limit of detection and CD4 counts increased to similar levels at six and twelve months for all treatment regimens. No statistically significant differences were observed for rate of treatment failure at six and twelve months. People on Atripla® generated lower healthcare costs for non-AIDS patients at £5,340 (£5,254 to £5,426) per patient-semester and £9,821 (£9,719 to £9,924) per patient-year that was £1,344 (95%CI £1,222 to £1,465) less per patient-semester and £1,954 (95%CI £1,801 to £2,107) less per patient-year compared with Truvada®+EFV; healthcare costs for AIDS patients were similar across all regimens.

Conclusion

The single pill regimen is as effective as the two- and three-pill regimens of the same drugs, but if started as first-line induction therapy there would be a 20% savings on healthcare costs at six and 17% of costs at twelve months compared with Truvada®+EFV, that generated the next lowest costs.  相似文献   

6.
Capsule: Current UK distributions of non-native birds poorly match areas identified as being climatically suitable.

Aims: Non-native species are spreading at unprecedented rates and though invasions are expected to increase under climate change, evidence for this is mixed. We assess climatic suitability throughout the UK based on the apparent match to the climate in species’ native ranges and investigate potential climatic limitation within the non-native range.

Methods: Climate was characterized within polygons representing the native ranges of 167 potentially invasive species. Parts of the UK with current and future climate similar to that in the native range were deemed climatically suitable. The incidence of recent observations inside and outside suitable areas was used to test hypotheses about climatic limitation of non-native ranges.

Results: Climate matching suggests that 69 of 167 non-native bird species could currently find climatically suitable areas for establishment in the UK. Future climate change would see this number increase by 14% by 2080. However, observed occurrences of non-native species in the UK were not significantly correlated to climatic suitability. Only 44 of the 69 species with suitable climate in the UK were present. Moreover, 85% of species observed in the UK had some UK occurrences in climatically unsuitable areas and for 57 species their entire UK range was in climatically unsuitable areas. Similar results were apparent for the subset of 12 species with established UK populations.

Conclusions: Climate matching provides a relatively poor indication of the extent of current and future suitable areas because species can adapt to new climates or other factors constrain the native range and many climatically suitable areas are currently unoccupied. Improvements to climate matching techniques and ongoing surveillance are required to refine predictions to support effective management policies.  相似文献   


7.
8.
Shamanic belief systems represent the first form of religious practice visible within the global archaeological record. Here we report on the earliest known evidence of shamanic costume: modified red deer crania headdresses from the Early Holocene site of Star Carr (c. 11 kya). More than 90% of the examples from prehistoric Europe come from this one site, establishing it as a place of outstanding shamanistic/cosmological significance. Our work, involving a programme of experimental replication, analysis of macroscopic traces, organic residue analysis and 3D image acquisition, metrology and visualisation, represents the first attempt to understand the manufacturing processes used to create these artefacts. The results produced were unexpected—rather than being carefully crafted objects, elements of their production can only be described as expedient.  相似文献   

9.
The zooplankton composition is studied in the thermokarst, glacial and meteorite lakes, channels, former riverbeds, and hollows in the basin of Anadyr’. We found 174 taxa: 78, Rotatoria, 55, Cladocera, and 41, Copepoda. The most diverse is the lake fauna: 51 taxa of Rotatoria, 48, Cladocera, and 37, Copepoda. The thermokarst Lake Maiorskoe hosts 68 taxa: 31, Rotatoria, 14, Cladocera, and 23, Copepoda, wheras the cold ultraoligotrophic Lake El’gygytgyn features only one species of Cyclop of the group scutifer Cyclops neymanae Strel., and Rotatoria and Cladocera are present as allochtonous forms. The Copepoda illustrate the relations of the Anadyr’ fauna with those of Europe, North America, and Japan.  相似文献   

10.
11.
12.
This paper argues that a two-tier system has evolved dividing intra-UK/EU marriages from extra-UK/EU marriages. For the former, marriage is a contract between two individuals overseen by a facilitating state. For the latter, marriage has become more of a legal status defined and controlled by an intrusive and obstructive state. I argue that this divergence in legislating regulation is steeped in an ethnicized imagining of ‘Britishness’ whereby the more noticeably ‘other’ migrants (by skin colour or religion) are perceived as a threat to the national character. The conceptualization of women as legally ‘disabled’ citizens (1870 Naturalisation Act) for whom a state must act as responsible patriarch, is a fundamental part of this imagining of the nation. The paper therefore examines the social (gendered and ethnicized) assumptions and political aims embedded within the legislation.  相似文献   

13.

Purpose

This study of seven foods assessed whether there are modes or locations of production that require significantly fewer inputs, and hence cause less pollution, than others. For example, would increasing imports of field-grown tomatoes from the Mediterranean reduce greenhouse gas (GHG) emissions by reducing the need for production in heated greenhouses in the UK, taking account of the additional transport emissions? Is meat production in the UK less polluting than the import of red meat from the southern hemisphere?

Methods

We carried out a life-cycle inventory for each commodity, which quantified flows relating to life-cycle assessment (LCA) impact categories: primary energy use, acidification, eutrophication, abiotic resource use, pesticide use, land occupation and ozone depletion. The system boundary included all production inputs up to arrival at the retail distribution centre (RDC). The allocation of production burdens for meat products was on the basis of economic value. We evaluated indicator foods from which it is possible to draw parallels for foods whose production follows a similar chain: tomatoes (greenhouse crops), strawberries (field-grown soft fruit), apples (stored for year-round supply or imported during spring and summer), potatoes (early season imports or long-stored UK produce), poultry and beef (imported from countries such as Brazil) and lamb (imported to balance domestic spring–autumn supply).

Results and discussion

Total pre-farm gate global warming potential (GWP) of potatoes and beef were less for UK production than for production in the alternative country. Up to delivery to the RDC, total GWP were less for UK potatoes, beef and apples than for production elsewhere. Production of tomatoes and strawberries in Spain, poultry in Brazil and lamb in New Zealand produced less GWP than in the UK despite emissions that took place during transport. For foods produced with only small burdens of GWP, such as apples and strawberries, the burden from transport may be a large proportion of the total. For foods with inherently large GWP per tonne, such as meat products, burdens arising from transport may only be a small proportion of the total.

Conclusions

When considering the GWP of food production, imports from countries where productivity is greater and/or where refrigerated storage requirement is less will lead to less total GWP than axiomatic preference for local produce. However, prioritising GWP may lead to increases in other environmental burdens, in particular leading to both greater demands on and decreasing quality of water resources.  相似文献   

14.
Abstract

We sketch the development of UK genetics and genomics research, and emphasize the UK's key role in the international genetics and genomics research community. We highlight in particular the part played by the UK's Research Councils and other funders. With the move from genomics to post-genomics research, the field is diversifying, and interdisciplinarity becomes increasingly important, as traditional disciplinary boundaries become blurred, or break down, in the face of newly emerging sciences. We consider the changing nature of health and ill health in the developed and developing world, and questions about the complex nature of the relationships between genes and the environment, and their future implications for human health and human populations. We describe the ESRC's activities, stressing the importance of both the social, ethical and legal issues raised by these emerging disciplines, and of public engagement. Finally, we link the data handling and analysis issues raised by these emerging sciences, with other new research areas, in particular the UK's e-Science programme.  相似文献   

15.
Catt  J.A.  Howse  K.R.  Christian  D.G.  Lane  P.W.  Harris  G.L.  Goss  M.J. 《Plant and Soil》1998,203(1):57-69
Nitrate losses in drainflow were measured over five years on eight hydrologically isolated field plots, pairs of which had the following cropping regimes: (a) a 3-yr unfertilised, ungrazed grass ley followed by winter and spring cereals, (b) mixed cropping including winter cover crops, spring cereals, winter cereals, winter fallow and spring beans, (c) a similar sequence to (b) but with a winter fallow replacing the cover crop in the first year and a winter cover crop replacing the fallow in the third year, and (d) continuous winter cereals (control plots). Less nitrate was lost in winter drainflow from winter cover crops than from the winter fallows, but over all five years less nitrate was leached from the continuous cereal plots than from those with mixed cropping. Most of the extra nitrate lost from the mixed cropping regimes probably resulted from mineralisation of the cover crop residues, which occurred at times when subsequent crops could not take advantage of the mineral nitrogen released. Crops grown after the grass ley and cover crops did not benefit from their residues, in terms of either grain yield or of total nitrogen uptake. We conclude that on heavy clay soils in UK a cropping regime of continuous winter cereals offers the best compromise between profitable crop production and minimised nitrate loss to surface waters.  相似文献   

16.
BackgroundAn understanding of women’s longitudinal patterns of smoking during the pre-conception, pregnancy and postnatal period and the factors associated with these patterns could help better inform smoking cessation services and interventions.MethodsLatent class analysis (LCA) was used to empirically identify women’s smoking patterns in a sample of 10,768 mothers from the 2010 UK Infant Feeding Survey. Multinomial logistic regression was used to identify characteristics associated with these patterns.ResultsLCA identified five distinct smoking patterns during the pre-conception, pregnancy and postnatal period: “non-smokers” (74.1% of women); “pregnancy-inspired quitters” (10.2%); “persistent smokers” (10.1%); “temporary quitters” (4.4%); and postnatal quitters (1.1%). Smoking patterns varied markedly according to socio-demographic variables and parity. After adjusting for these variables, mothers who lived during pregnancy with a partner who smoked were more likely to be temporary quitters (aOR 2.64, 95% CI 1.74–3.99) or persistent smokers (aOR 3.32, 95% CI 2.34–4.72) than pregnancy-inspired quitters. Mothers who lived during pregnancy with someone else other than a partner who smoked were more likely to be persistent smokers (aOR 2.34, 95% CI 1.38–3.97) or postnatal quitters (aOR 2.97, 95% CI 1.07–8.24) than pregnancy-inspired quitters. Mothers given information on how their partner could stop smoking if they lived during pregnancy with a smoking partner were less likely to be persistent smokers (aOR 0.42, 95% CI 0.27–0.65) than pregnancy-inspired quitters.ConclusionHealth professionals should ask about smoking at every opportunity, and refer women who self-report as current smokers to an evidence based smoking cessation service.  相似文献   

17.
The Na,K-ATPase is a major ion transport protein found in higher eukaryotic cells. The enzyme is composed of two subunits, α and β, and tissue-specific isoforms exist for each of these, α1, α2 and α3 and β1, β2 and β3. We have proposed that an additional α isoform, α4, exists based on genomic and cDNA cloning. The mRNA for this gene is expressed in rats and humans, exclusively in the testis, however the expression of a corresponding protein has not been demonstrated. In the current study, the putative α4 isoform has been functionally characterized as a novel isoform of the Na,K-ATPase in both rat testis and in α4 isoform cDNA transfected 3T3 cells. Using an α4 isoform-specific polyclonal antibody, the protein for this novel isoform is detected for the first time in both rat testis and in transfected cell lines. Ouabain binding competition assays reveal the presence of high affinity ouabain receptors in both rat testis and in transfected cell lines that have identical K D values. Further studies of this high affinity ouabain receptor show that it also has high affinities for both Na+ and K+. The results from these experiments definitively demonstrate the presence of a novel isoform of the Na,K-ATPase in testis. Received: 4 December 1998/Revised: 1 February 1999  相似文献   

18.
We present the findings of a DNA barcoding study of the UK tree flora, implemented as part of an innovative, research‐based science education programme called ‘Tree School’. The UK tree flora comprises native and introduced species, and is a taxonomically diverse study group for the exploration of the potential and limitations of DNA barcoding. The children participating in the project collected voucher specimens and generated DNA barcode sequences from trees and shrubs found in the grounds and surrounding woodlands of a residential field centre in Dorset, UK. We assessed the potential of rbcL and matK markers for amplification and DNA sequencing success and for species discrimination among the 67 tree and shrub species included in this study. Although we achieved 100% PCR amplification and sequencing success for rbcL and matK, mononucleotide repeats affected sequence quality in matK for some taxonomic groups (e.g. Rosaceae). Species discrimination success ranged from 65% to 71% using tree‐based methods to 86% using BLASTN. The occurrence of known hybrids (diploid and polyploid) and their progenitors on the study site reduced the overall species discrimination success for both loci. This study demonstrates that, even in a floristic context, rbcL and matK alone are insufficient for the discrimination of UK tree species, especially where taxonomically complex groups are present. From a science education perspective, DNA barcoding represents a compelling and accessible platform for the engagement of non‐experts in ongoing research, providing an opportunity for them to contribute authentic scientific data to an international research campaign.  相似文献   

19.
This article examines the “Syrian Vulnerable Persons Resettlement Programme” (SVPRP) as a specific British response to the “European refugee crisis”. Based on an analysis of media reporting (2014–17) and empirical evidence from agencies and volunteers tasked with implementing the programme, this essay reveals the ethical and political ambiguities at its heart. By focusing on the notion of “vulnerability” I argue that the humanitarian configuration of a refugee worthy of care is implicated in two significant practices: exceptionalising a small group of Syrians as legitimate targets for compassion and constructing compassion itself as a rationed resource in a climate of anti-immigrant hostility, austerity and Brexit.  相似文献   

20.
Objective:  This review highlights the role of cytopathology in cancer management within UK Head and Neck Cancer Networks and informs on the issues raised by recent UK Department of Health documents and other UK professional guidance. UK guidance requires the formal involvement of cytopathologists within multidisciplinary cancer teams, with medical and non-medical cytopathology staff setting up and running rapid access lump clinics, and support for image-guided fine needle aspiration cytology (FNAC) services. UK guidance also makes recommendations for training, resources and quality control. This review also highlights the resource gap between best practice evidence-based guidance for head and neck (HN) cancer services and existing UK provision for cytopathology, as evidenced by lack of availability of experienced staff and adequacy of training and quality control (QC). Finally, it stresses the importance in the UK of the Royal College of Pathologists' guidance, which defines the need for training, the experience needed for new consultants, the requirements for audit and QC. The implications for the additional resources required for HN cancer cytopathology services are discussed. Recent professional guidance specifying the provision of HN cancer services in the UK includes a cytopathology service for cancer networks, such as rapid access FNAC clinics. Although these clinics already operate in some institutions, there are many institutions where they do not and where the provision of cytopathology services would have to be restructured. This would need the support of local cancer networks and their acceptance of the detailed requirements for cytopathology, including resources, training and QC. The standards are not defined locally, as Strategic Health Authorities and Primary Care Trusts have been instructed by the Department of Health to support, invest and implement them.  相似文献   

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