4,100 research outputs found
Elastic-plastic solutions for expanding cavities embedded in two different cohesive-frictional materials
An analytical solution of cavity expansion in two different concentric regions of soil is developed and investigated in this paper. The cavity is embedded within a soil with finite radial dimension and surrounded by a second soil, which extends to infinity. Large-strain quasi-static expansion of both spherical and cylindrical cavities in elastic-plastic soils is considered. A non-associated Mohr–Coulomb yield criterion is used for both soils. Closed-form solutions are derived, which provide the stress and strain fields during the expansion of the cavity from an initial to a final radius. The analytical solution is validated against finite element simulations, and the effect of varying geometric and material parameters is studied. The influence of the two different soils during cavity expansion is discussed by using pressure–expansion curves and by studying the development of plastic regions within the soils. The analytical method may be applied to various geotechnical problems, which involve aspects of soil layering, such as cone penetration test interpretation, ground-freezing around shafts, tunnelling, and mining
Rapid assessment of surface-water flood-management options in urban catchments
This is the final version of the article. Available from the publisher via the DOI in this record.Surface-water flooding in urban areas has become a pressing issue due to changing precipitation patterns, expanding urban areas and ageing drainage infrastructure. Selection of flood-management options for widespread implementation using quantitative performance measures is both technically and computationally demanding, which limits the evidence available for decision support. This study presents a new framework for surface-water flood-intervention assessment at high resolution. The framework improves computational efficiency through utilisation of accessible data, simplified representations of interventions and a resource efficient cellular automata flood model. The advantages of this framework are demonstrated through an example case study where the performance of 12 high-level intervention strategies has been evaluated. Results from the case study demonstrate that the framework is able to provide quantitative performance values for a range of interventions. The speed of analysis supports the application of the framework as a decision-making tool for urban water planning.This research was supported by three UK research council funded programmes:
the EPSRC Centre for Doctoral Training in Water Informatics
Science and Engineering [grant number EP/L016214/1], the EPSRC research
fellowship Safe & SuRe water management [grant number EP/K006924/1],
and the NERC project SINATRA - Susceptibility of catchments to INTense
RAinfall and flooding [grant number NE/K008765/1]. LiDAR was provided
by the Environment Agency and mapping was provided through OS
Mastermap data on the Digimap service
Prevention and management of excessive gestational weight gain: a survey of overweight and obese pregnant women
Background - Excessive gestational weight gain is associated with adverse infant, childhood and maternal outcomes and research to develop interventions to address this issue is ongoing. The views of women on gestational weight gain and the resources they would consider helpful in addressing this are however largely unknown. This survey aimed to determine the views of newly pregnant women, living in areas of social disadvantage, on 1) their current body weight and potential gestational weight gain and 2) the resources or interventions they would consider helpful in preventing excessive gestational weight gain.
Methods - A convenience sample of overweight and obese pregnant women living in Fife, UK, were invited to complete a short anonymised questionnaire at their 12 week booking visit.
Results - 428 women, BMI>25 kg/m2, completed the questionnaire. Fifty-four per cent of respondents were obese (231) and 62% were living in areas of mild to moderate deprivation. Over three-quarters of participants felt dissatisfied with their current weight (81%). The majority of women (60%) expressed some concern about potential weight gain. Thirty-nine percent were unconcerned about weight gain during their pregnancy, including 34 women (19%) who reported having retained weight gained in earlier pregnancies. Amongst those concerned about weight gain advice on physical activity (41%) and access to sports/leisure facilities were favoured resources (36%). Fewer women (12%) felt that group sessions on healthy eating or attending a clinic for individualised advice (14%) would be helpful. "Getting time off work" was the most frequently cited barrier (48%) to uptake of resources other than leaflets.
Conclusions- These data suggest a lack of awareness amongst overweight and obese women regarding excessive gestational weight gain. Monitoring of gestational weight gain, and approaches for its management, should be formally integrated into routine antenatal care. Barriers to the uptake of resources to address weight gain are numerous and must be considered in the design of future interventions and services
Gateway vectors for efficient artificial gene assembly in vitro and expression in yeast Saccharomyces cerevisiae
Peer reviewedPublisher PD
Provision of foot health services for people with rheumatoid arthritis in New South Wales: a web-based survey of local podiatrists
Background: It is unclear if podiatric foot care for people with rheumatoid arthritis (RA) in New South Wales (NSW) meets current clinical recommendations. The objective of this study was to survey podiatrists' perceptions of the nature of podiatric foot care provision for people who have RA in NSW.Methods: An anonymous, cross-sectional survey with a web-based questionnaire was conducted. The survey questionnaire was developed according to clinical experience and current foot care recommendations. State registered podiatrists practising in the state of NSW were invited to participate. The survey link was distributed initially via email to members of the Australian Podiatry Association (NSW), and distributed further through snowballing techniques using professional networks. Data was analysed to assess significant associations between adherence to clinical practice guidelines, and private/public podiatry practices.Results: 86 podiatrists participated in the survey (78% from private practice, 22% from public practice). Respondents largely did not adhere to formal guidelines to manage their patients (88%). Only one respondent offered a dedicated service for patients with RA. Respondents indicated that the primary mode of accessing podiatry was by self-referral (68%). Significant variation was observed regarding access to disease and foot specific assessments and treatment strategies. Assessment methods such as administration of patient reported outcome measures, vascular and neurological assessments were not conducted by all respondents. Similarly, routine foot care strategies such as prescription of foot orthoses, foot health advice and footwear were not employed by all respondents.Conclusions: The results identified issues in foot care provision which should be explored through further research. Foot care provision in NSW does not appear to meet the current recommended standards for the management of foot problems in people who have RA. Improvements to foot care could be undertaken in terms of providing better access to examination techniques and treatment strategies that are recommended by evidence based treatment paradigms. © 2013 Hendry et al.; licensee BioMed Central Ltd
Epistemic and Ontic Quantum Realities
Quantum theory has provoked intense discussions about its interpretation since its pioneer days. One of the few scientists who have been continuously engaged in this development from both physical and philosophical perspectives is Carl Friedrich von Weizsaecker. The questions he posed were and are inspiring for many, including the authors of this contribution. Weizsaecker developed Bohr's view of quantum theory as a theory of knowledge. We show that such an epistemic perspective can be consistently complemented by Einstein's ontically oriented position
Building professional discourse in emerging markets: Language, context and the challenge of sensemaking
Using ethnographic evidence from the former Soviet republics, this article examines a relatively new and mainly unobserved in the International Business (IB) literature phenomenon of communication disengagement that manifests itself in many emerging markets. We link it to the deficiencies of the local professional business discourse rooted in language limitations reflecting lack of experience with the market economy. This hampers cognitive coherence between foreign and local business entities, adding to the liability of foreignness as certain instances of professional experience fail to find adequate linguistic expression, and complicates cross-cultural adjustments causing multi-national companies (MNCs) financial losses. We contribute to the IB literature by examining cross-border semantic sensemaking through a retrospectively constructed observational study. We argue that a relative inadequacy of the national professional idiom is likely to remain a feature of business environment in post-communist economies for some time and therefore should be factored into business strategies of MNCs. Consequently, we recommend including discursive hazards in the risk evaluation of international projects
A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion
PublishedLetterThousands of transiting exoplanets have been discovered, but spectral analysis of their atmospheres has so far been dominated by a small number of exoplanets and data spanning relatively narrow wavelength ranges (such as 1.1 to 1.7 μm). Recent studies show that some hot- Jupiter exoplanets have much weaker water absorption features in their near-infrared spectra than predicted. The low amplitude of water signatures could be explained by very low water abundances, which may be a sign that water was depleted in the protoplanetary disk at the planet’s formation location, but it is unclear whether this level of depletion can actually occur. Alternatively, these weak signals could be the result of obscuration by clouds or hazes, as found in some optical spectra. Here we report results from a comparative study of ten hot Jupiters covering the wavelength range 0.3–5 micrometres, which allows us to resolve both the optical scattering and infrared molecular absorption spectroscopically. Our results reveal a diverse group of hot Jupiters that exhibit a continuum from clear to cloudy atmospheres. We find that the difference between the planetary radius measured at optical and infrared wavelengths is an effective metric for distinguishing different atmosphere types. The difference correlates with the spectral strength of water, so that strong water absorption lines are seen in clear-atmosphere planets and the weakest features are associated with clouds and hazes. This result strongly suggests that primordial water depletion during formation is unlikely and that clouds and hazes are the cause of weaker spectral signatures.European Research Council European Union’s Seventh Framework Programme (FP7/2007-2013)NASACNES and the French Agence Nationale de la Recherche (ANR)UK Science and Technology Facilities Council (STFC)NSFTennessee State UniversityState of Tennesse
MRI of the lung (3/3)-current applications and future perspectives
BACKGROUND: MRI of the lung is recommended in a number of clinical indications. Having a non-radiation alternative is particularly attractive in children and young subjects, or pregnant women. METHODS: Provided there is sufficient expertise, magnetic resonance imaging (MRI) may be considered as the preferential modality in specific clinical conditions such as cystic fibrosis and acute pulmonary embolism, since additional functional information on respiratory mechanics and regional lung perfusion is provided. In other cases, such as tumours and pneumonia in children, lung MRI may be considered an alternative or adjunct to other modalities with at least similar diagnostic value. RESULTS: In interstitial lung disease, the clinical utility of MRI remains to be proven, but it could provide additional information that will be beneficial in research, or at some stage in clinical practice. Customised protocols for chest imaging combine fast breath-hold acquisitions from a "buffet" of sequences. Having introduced details of imaging protocols in previous articles, the aim of this manuscript is to discuss the advantages and limitations of lung MRI in current clinical practice. CONCLUSION: New developments and future perspectives such as motion-compensated imaging with self-navigated sequences or fast Fourier decomposition MRI for non-contrast enhanced ventilation- and perfusion-weighted imaging of the lung are discussed. Main Messages • MRI evolves as a third lung imaging modality, combining morphological and functional information. • It may be considered first choice in cystic fibrosis and pulmonary embolism of young and pregnant patients. • In other cases (tumours, pneumonia in children), it is an alternative or adjunct to X-ray and CT. • In interstitial lung disease, it serves for research, but the clinical value remains to be proven. • New users are advised to make themselves familiar with the particular advantages and limitations
A new multistage lattice vector quantization with adaptive subband thresholding for image compression
Lattice vector quantization (LVQ) reduces coding complexity and computation due to its regular structure. A new multistage LVQ (MLVQ) using an adaptive subband thresholding technique is presented and applied to image compression. The technique concentrates on reducing the quantization error of the quantized vectors by "blowing out" the residual quantization errors with an LVQ scale factor. The significant coefficients of each subband are identified using an optimum adaptive thresholding scheme for each subband. A variable length coding procedure using Golomb codes is used to compress the codebook index which produces a very efficient and fast technique for entropy coding. Experimental results using the MLVQ are shown to be significantly better than JPEG 2000 and the recent VQ techniques for various test images
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