6,427 research outputs found

    Out-of-plane thermopower of strongly correlated layered systems: an application to Bi_2(Sr,La)_2CaCu_2O_{8+\delta}

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    We calculate the out-of-plane thermopower in a quasi-two dimensional system, and argue that this quantity is an effective probe of the asymmetry of the single-particle spectral function. We find that the temperature and doping dependence of the out-of-plane thermopower in Bi_2(Sr,La)_2CaCu_2O_{8+\delta} single crystals is broadly consistent with the behavior of the spectral function determined from ARPES and tunneling experiments. We also investigate the relationship between out-of-plane thermopower and entropy in a quasi-two dimensional material. We present experimental evidence that at moderate temperatures, there is a qualitative correspondence between the out-of-plane thermopower in Bi_2(Sr,La)_2CaCu_2O_{8+\delta}, and the entropy obtained from specific heat measurements. Finally, we argue that the derivative of the entropy with respect to particle number may be the more appropriate quantity to compare with the thermopower, rather than the entropy per particle.Comment: 11 pages, 5 figures. v2: substantially rewritten, including a more detailed analysis of the relationship between thermopower and entrop

    The concept of authorship in the work of Sara Coleridge

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    This thesis aims to establish Sara Coleridge’s place in literary history. Her authorial achievements have been obscured by two factors. First, she has been the subject of predominantly biographical, rather than literary attention. While this thesis does draw on specific biographical contexts, its approach is literary and critical throughout. Second, Coleridge’s mature writings are theological, and consist of polemical contributions to religious debate in the two decades following the Reform Act of 1832. In order to analyse the qualities of Coleridge’s mature authorship, this study undertakes the necessary historical and theological contextualization. Coleridge’s politico-religious setting requires innovatory authorial methods: she is, above all, a dialogic writer. The thesis examines her evolving dialogue with her ‘literary fathers’, and addresses the relationship between her editing of STC and her original writing. Bakhtinian theory informs the approach of this thesis to Coleridge’s textual analysis of STC and his sources. Gadamer’s hermeneutic concept of the ‘fusion’ of historical ‘horizons’ informs the study’s analysis of her appropriation of STC’s thought, which she reworks in addressing post-Reform fractures. Prevailing polemical styles exacerbate such fractures, Coleridge maintains. This study finds that Coleridge is committed to individual religious liberty, and an inclusive theology underpinned by Kantian epistemology. This is the basis for her sustained critique of the Oxford Movement’s authoritarian tendencies. In her theological writings, therefore, she develops dialogic styles and forms by which to convey her liberal religious philosophy. Along with published sources, this thesis refers to the unpublished writings of 1850 and 1851 that reveal the full extent of Coleridge’s literary innovation. This study is constructed chronologically; it aims to elucidate Coleridge’s development through the stages of her writing life, and to uncover the connections between the various strands of her work. It shows that dialogic elements are present from an early stage of Coleridge’s literary career, and that her writings in different genres all contribute to her ultimate vocation of dialogic religious authorship

    Tumour angiogenesis: The gap between theory and experiment

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    A common experimental technique for viewing in vivo angiogenesis utilises tumours implanted into a test animal cornea. The cornea is avascular but the tumour promotes vascularisation from the limbus and the new blood vessels can be readily observed through the transparent cornea. Many of the early mathematical models for tumour angiogenesis used this scenario as their experimental template and as such assumed that there is a large gap, of the order of 2 mm, between the tumour and neighbouring vasculature at the onset of angiogenesis. In this work we consider whether the assumption that there is a significant gap between the tumour and neighbouring vasculature is unique to intra-cornea tumour implants, or whether this characterises avascular tumour growth more generally. To do this we utilise a simple scaling argument, derive a multi-compartment model for tumour growth, and consider in vivo images. This analysis demonstrates that the corneal implant experiments and the corresponding mathematical models cannot generally be applied to a clinical setting

    Older adults' evaluations of the standard and modified pedometer-based Green Prescription

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    INTRODUCTION: The Green Prescription is a primary care programme designed to increase physical activity in individuals with low activity levels. Older adults tend to engage in insufficient physical activity to obtain health-related gain. AIM: To examine participants’ ratings of the Healthy Steps intervention and to assess how participants rated the use of a pedometer-based Green Prescription in aiding their physical activity. METHODS: In total, 330 community-dwelling older adults who have low levels of activity were randomised to receive either a standard time-based Green Prescription or a modified pedometer-based Green Prescription. Post-intervention, 259 participants completed the participant evaluation questionnaire via postal survey. Data were analysed using descriptive statistics and Chi-squared analyses. RESULTS: The standard components of the Green Prescription (general practitioner consultations and telephone counselling) received similar and higher ratings across both allocation groups than the use of print materials. A pedometer-based Green Prescription was rated as being helpful in aiding physical activity. DISCUSSION: This study supports the importance of general practitioners’ initial role in prescribing physical activity for older adults and of ongoing telephone support for longer-term adherence. Incorporating a pedometer can be effective in helping low-active older adults initiate and maintain regular physical activity

    Documentation for the machine-readable version of the SAO-HD-GC-DM cross index version 1983

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    An updated and extended machine readable version of the Smithsonian Astrophysical Observatory star catalog (SAO) is described. A correction of all errors which were found since preparation of the original catalog which resulted from misidentifications and omissions of components in multiple star systems and missing Durchmusterung numbers (the common identifier) in the SAO Catalog are included and component identifications from the Index of Visual Double Stars (IDS) are appended to all multiple SAO entries with the same DM numbers, and lower case letter identifiers for supplemental BD stars are added. A total of 11,398 individual corrections and data additions is incorporated into the present version of the cross index

    Frontier exploration and the North Atlantic Igneous Province : new insights from a 2.6 km offshore volcanic sequence in the NE Faroe–Shetland Basin

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    Acknowledgements and Funding This work was funded by Chevron. The authors would like to acknowledge the Chevron West of Shetlands team along with the Joint Venture partners OMV, Faroe Petroleum and Indemitsu for access to data along with permission to publish this study. PGS is thanked for access to the Corona Ridge Regional Geostreamer (CRRG) data and permission to publish the seismic line. The paper was improved thanks to insightful reviews by S. M. Jones and A. Saunders, which substantially improved an earlier draft. J. Still and F. Thompson gave invaluable technical support at the University of Aberdeen, and K. Wall helped with real-time cuttings analysis.Peer reviewedPostprin

    Secular trends in under-reporting in young people

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    Original article can be found at: http://journals.cambridge.org/action/displayJournal?jid=BJN Copyright The Authors. DOI: 10.1079/BJN20041307National survey data show that reported energy intake has decreased in recent decades despite a rise in the prevalence of obesity. This disparity may be due to a secular increase in under-reporting or a quantitatively greater decrease in energy expenditure. This study examines the extent of under-reporting of energy intake in the National Diet and Nutrition Survey (NDNS) in young people aged 4–18 years in 1997 using published equations to calculate estimated energy requirements. It explores secular changes by comparison with the Diets of British School Children (DBSC) survey in 10–11- and 14–15-year-olds in 1983. In the NDNS, under-reporting (estimated energy requirements – energy intake) represented 21 % of energy needs in girls and 20 % in boys. The magnitude of under-reporting increased significantly with age (P<0·001) and was higher in overweight than lean individuals over 7 years of age. To compare reported energy intake in DBSC and NDNS, the estimated physical activity level from dietary records (dPAL=reported energy intake/predicted BMR) was calculated. If there were no under-reporting, dPAL would represent the subject's true activity level. However, dPAL from the NDNS was significantly lower than that from the DBSC by 8 % and 9 % in boys and girls for those aged 10–11 years, and by 14 % and 11 % for 14–15-year-olds respectively, reaching physiologically implausible levels in the 14–15-year-old girls (dPAL=1·17). If activity levels have remained constant between the two surveys, under-reporting has increased by 8–14 %. The evidence supports a secular trend towards increased under-reporting between the two surveys, but the precise magnitude cannot be quantified in the absence of historical measures of energy expenditure.Peer reviewe
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