1,027 research outputs found

    Evaluation of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seed tree mortality on the Clearwater National Forest, ID

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    Urban grasslands support threatened water voles

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    Urbanisation is often linked with habitat loss and a reduction in species richness but some species may be able to adapt to urban environments. Water voles Arvicola amphibius, a rapidly declining species in the UK, have recently been recorded in isolated grassland habitats in Glasgow, Scotland’s largest city (human population 1.2 million). The aim of this study was to determine the distribution and habitat characteristics of water vole populations occupying these dry grasslands. Field work was undertaken from March to October 2014 in a 34 km2 study area located 3 km east of the city centre. Field sign transects recorded water vole presence in 21/65 (32%) and 19/62 (31%) surveyed sites in spring and autumn, respectively. Vole occupancy increased with distance from water and was greatest in parkland, followed by sites with rank vegetation and roadside habitats. Occupancy was lower where signs of predators were recorded but surprisingly occupancy was found to be greater in the most disturbed sites, perhaps linked to the fact that many of these sites were public parks containing suitable grassland. Sites occupied by water voles were classed as neutral grasslands with species composition dominated by two main species. The number of grassland sites occupied by water voles, especially within public areas suggests that careful management of these urban grassland habitats will benefit the conservation of this highly threatened species in the UK

    Spin correlations in Ca3Co2O6: A polarised-neutron diffraction and Monte Carlo study

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    We present polarised-neutron diffraction measurements of the Ising-like spin-chain compound Ca3Co2O6 above and below the magnetic ordering temperature TN. Below TN, a clear evolution from a single-phase spin-density wave (SDW) structure to a mixture of SDW and commensurate antiferromagnet (CAFM) structures is observed on cooling. For a rapidly-cooled sample, the majority phase at low temperature is the SDW, while if the cooling is performed sufficiently slowly, then the SDW and the CAFM structure coexist between 1.5 and 10 K. Above TN, we use Monte Carlo methods to analyse the magnetic diffuse scattering data. We show that both intra- and inter-chain correlations persist above TN, but are essentially decoupled. Intra-chain correlations resemble the ferromagnetic Ising model, while inter-chain correlations resemble the frustrated triangular-lattice antiferromagnet. Using previously-published bulk property measurements and our neutron diffraction data, we obtain values of the ferromagnetic and antiferromagnetic exchange interactions and the single-ion anisotropy.Comment: 10 pages, 7 figure

    Respiratory admissions linked to air pollution in a medium sized city of the UK:A case-crossover study

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    This study, from the Tayside Pollution Research Programme (TPRP), aims to investigate the effects of air pollution on respiratory hospital admissions in adults and children &lt; 16 y of age, over a 14-year period, in Dundee, Scotland (population circa 148,270). We conducted a case-crossover study using routinely collected healthcare records from Ninewells Hospital, Dundee, Scotland from 2004 to 2017. Respiratory hospitalisation events were linked to daily nitric oxide gases (NOx, NO2, NO) extracted from publicly available data over this period. We used distributed lag models to allow for delayed effects of air pollutants up to 14 days. A total of 34,192 hospital admissions for a respiratory condition were included in this study (children = 9,501; adults = 24,691). Respiratory admissions in children were significantly associated with cumulative 14-day exposure to NOx (RR for a 10 µg m–3 increase in concentration 1.020; 95% confidence interval 1.010–1.031), NO2 (RR 1.086; 95% CI 1.036–1.139) and NO (RR 1.033; 95% CI 1.016–1.052). Similar estimates were observed for acute respiratory infection categories in children. Effects appeared to be somewhat delayed, with the largest estimates mostly observed around lag 6. No significant association was seen for respiratory admissions in adults. This study shows that both NO and NO2 are associated with increased respiratory hospital admissions in children &lt; 16 y of age, and that much more should be done to improve and enforce the established legal NOx pollution limits in cities for the sake of our children’s health.</p

    Analysing passengers' behaviours when boarding trains to improve rail infrastructure and technology

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    Concentrated boarding describes the phenomenon when rail passengers congregate in certain areas of the platform and board the train carriages that stop near these areas. This influences the distribution of passengers throughout the carriages, which can negatively affect passenger comfort, safety at the platform-train interface, efficiency of the rail network, and the reputation of rail travel as a whole. This project aimed to determine whether concentrated boarding occurs in stations in the UK in order to understand its relevance for future rolling stock, infrastructure design and its associated manufacturing research. Video recording technology was used to observe the movements of passengers in Oxford Station and data was collected for nine individual trains. By reviewing the recordings, the number of passengers boarding through each door of the trains was determined, and the boarding distribution along the length of the platform was plotted. Several reasons for noted trends are offered, and potential solutions proposed. The use of real time information could be invaluable to minimise concentrated boarding, as it would allow passengers to make informed decisions as to where they could board trains to have a better journey experience. These findings indicate the relevance of a human-centred design process, particularly the user research stages, in the process of defining priorities for manufacturing and engineering

    Effect of tumor necrosis factor antagonism on allergen-mediated asthmatic airway inflammation

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    SummaryObjectiveTo assess whether tumor necrosis factor (TNF) antagonism can attenuate eosinophilic airway inflammation in patients with mild-to-moderate allergic asthma.DesignRandomized, double-blind, placebo-controlled trial.SettingNational Institutes of Health (NIH) Clinical Center.PatientsTwenty-six patients with mild-to-moderate allergic asthma, receiving only inhaled β-2-agonists, who demonstrated both an early and late phase response to inhalational allergen challenge.InterventionInjection of a soluble TNF receptor (TNFR:Fc, etanercept, Enbrel) or placebo, 25mg subcutaneously, twice weekly for 2 weeks, followed by a bronchoscopic segmental allergen challenge.MeasurementsThe primary outcome measure was whether TNFR:Fc can access the lung and inhibit TNF bioactivity. Secondary outcome measures included pulmonary eosinophilia, Th2-type cytokines, and airway hyperresponsiveness.ResultsAnti-TNF therapy was associated with transient hemiplegia in one patient, which resulted in suspension of the study. Data from the 21 participants who completed the study were analyzed. Following treatment, patients receiving anti-TNF therapy had significantly increased TNFR2 levels in epithelial lining fluid (ELF) (P<0.001), consistent with delivery of TNFR:Fc to the lung. TNF antagonism did not attenuate pulmonary eosinophilia and was associated with an increase in ELF IL-4 levels (P=0.033) at 24h following segmental allergen challenge. TNF antagonism was not associated with a change in airway hyperresponsiveness to methacholine.ConclusionsTNF antagonism may not be effective for preventing allergen-mediated eosinophilic airway inflammation in mild-to-moderate asthmatics. Transient hemiplegia, which may mimic an evolving stroke, may be a potential toxicity of anti-TNF therapy

    Immobilisation of Higher Activity Wastes from Nuclear Reactor Production of 99

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    A variety of intermediate- and low-level liquid and solid wastes are produced from reactor production of 99Mo using UAl alloy or UO2 targets and in principle can be collectively or individually converted into waste forms. At ANSTO, we have legacy acidic uranyl-nitrate-rich intermediate level waste (ILW) from the latter, and an alkaline liquid ILW, a U-rich filter cake, plus a shorter lived liquid stream that rapidly decays to low-level waste (LLW) standards, from the former. The options considered consist of cementitious products, glasses, glass-ceramics, or ceramics produced by vitrification or hot isostatic pressing for intermediate-level wastes. This paper discusses the progress in waste form development and processing to treat ANSTO’s ILW streams arising from 99Mo. The various waste forms and the reason for the process option chosen will be reviewed. We also address the concerns over adapting our chosen process for use in a hot-cell environment
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