3,687 research outputs found

    Evidence for heat losses via party wall cavities in masonry construction

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    This paper presents empirical evidence and analysis that supports the existence of a significant heat loss mechanism resulting from air movement through cavities in party walls in masonry construction. A range of heat loss experiments were undertaken as part of the Stamford Brook housing field trial in Altrincham in the United Kingdom. Co-heating tests showed a large discrepancy between the predicted and measured whole house heat loss coefficients. Analysis of the co-heating results, along with internal temperature data, thermal imaging and a theoretical analysis indicated that the most likely explanation for the discrepancy was bypassing of the thermal insulation via the uninsulated party wall cavities. The data show that such a bypass mechanism is potentially the largest single contributor to heat loss in terraced dwellings built to the 2006 revision of the Building Regulations. A comparable convective heat bypass associated with masonry party walls was identified in the late 1970s during the course of the Twin Rivers Project in the United States, albeit in a somewhat different construction from that used at Stamford Brook. A similar effect was also reported in the United Kingdom in the mid 1990s. However, it appears that no action was taken at that time either to confirm the results, to develop any technical solutions, or to amend standards for calculating heat losses from buildings. Current conventions for heat loss calculations in the United Kingdom do not take account of heat losses associated with party walls and it is suggested by the authors that such conventions may need to be updated to take account of the effect described in this paper. In the final part of the paper, the authors propose straightforward solutions to prevent bypassing of roof insulation via party walls by for example filling the cavity of the party wall with mineral fibre insulation, or by inserting a cavity closer across the cavity in the plane of the roof insulation.Practical application: The heat bypass mechanism described in this paper is believed by the authors to contribute to a significant proportion of heat loss from buildings in the UK constructed with clear cavities such as those found in separating walls between cavity masonry dwellings. It is proposed that relatively simple design changes could be undertaken to eliminate such heat loss pathways from new buildings. In addition, simple and cost effective measures are envisaged that could be used to minimise or eliminate the bypass from existing buildings. Such an approach could give rise to a significant reduction in carbon emissions from UK housing

    Lost in transition? Access to and uptake of adult health services and outcomes for young people with type 1 diabetes in regional New South Wales

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    Objective: To document diabetes health services use and indices of glycaemic management of young people with type 1 diabetes from the time of their first contact with adult services, for those living in regional areas compared with those using city and state capital services, and compared with clinical guideline targets. Design, setting and subjects: Case note audit of 239 young adults aged 18-28 years with type 1 diabetes accessing five adult diabetes services before 30 June 2008 in three geographical regions of New South Wales: the capital (86), a city (79) and a regional area (74). Main outcome measures: Planned (routine monitoring) and unplanned (hospital admissions and emergency department attendance for hypoglycaemia or hyperglycaemia) service contacts; recorded measures of glycated haemoglobin (HbA1c), body mass index (BMI), and blood pressure (BP). Results: Routine preventive service uptake during the first year of contact with adult services was significantly higher in the capital and city. Fewer regional area patients had records of complications assessment and measurements of HbA1c, BMI and BP across all audited years of contact (HbA1c: 73% v 94% city, 97% capital; P 8.0% (79% v 62% city, 56% capital) and lowest proportion < 7% (4% v 7%, 22%) (both P < 0.001). Fewer young people made unplanned use of acute services for diabetes crisis management in the capital (24% v 49% city, 50% regional area; P < 0.001). In the regional area, routine review did not occur reliably even annually, with marked attrition of patients from adult services after the first year of contact. Conclusion: Inadequate routine specialist care, poor diabetes self-management and frequent use of acute services for crisis management, particularly in regional areas, suggest service redesign is needed to encourage young people's engagement

    Services doing the best they can: Service experiences of young adults with type 1 diabetes mellitus in rural Australia

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    Aims and objectives. To describe the healthcare experiences of young adults with type 1 diabetes who access diabetes services in rural areas of New South Wales, Australia. Background. The incidence of type 1 diabetes in childhood and adolescence is increasing worldwide; internationally, difficulties are encountered in supporting young people during their transition from children to adulthood. Consumers' experiences and views will be essential to inform service redesign. Design. This was a qualitative exploratory study. Methods. Semistructured telephone interviews were conducted with 26 people aged 18-28years living rurally, recruited through staff in four regional healthcare centres in 2008. Results. Two key themes were evident: lack of access (comprised of transfer to adult services, access to health professionals and access to up-to-date information) and age-appropriate provision. The impact of place of residence and personal motivation crossed all themes. Participants contrasted unfavourably the seamless care and support received from paediatric outreach services with the shortages in specialist and general practice-based care and information and practical problems of service fragmentation and lack of coordination experienced as adults. They identified a range of issues including need for ongoing education, age-appropriate services and support networks related to developing their ability to self-manage. They valued personal service; online and electronic support was seldom volunteered as an alternative. Conclusion. This was a first view of rural young people's experiences with adult diabetes services. Reported experiences were in line with previous reports from other settings in that they did not perceive services in this rural area of Australia as meeting their needs; suggestions for service redesign differed. Relevance to clinical practice. New models of age-appropriate service provision are required, to meet their needs for personal as well as other forms of support, whilst acknowledging the very real resource limitations of these locations. © 2012 Blackwell Publishing Ltd

    Predictive Factors for and Complications of Bronchiectasis in Common Variable Immunodeficiency Disorders

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    Bronchiectasis is a frequent complication of common variable immunodeficiency disorders (CVID). In a cohort of patients with CVID, we sought to identify predictors of bronchiectasis. Secondly, we sought to describe the impact of bronchiectasis on lung function, infection risk, and quality of life. We conducted an observational cohort study of 110 patients with CVID and an available pulmonary computed tomography scan. The prevalence of bronchiectasis was 53%, with most of these patients (54%) having mild disease. Patients with bronchiectasis had lower median serum immunoglobulin (Ig) concentrations, especially long-term IgM (0 vs 0.25 g/l; p < 0.01) and pre-treatment IgG (1.3 vs 3.7 g/l; p < 0.01). CVID patients with bronchiectasis had worse forced expiratory volume in one second (2.10 vs 2.99 l; p < 0.01) and an annual decline in forced expiratory volume in one second of 25 ml/year (vs 8 ml/year in patients without bronchiectasis; p = 0.01). Patients with bronchiectasis also reported more annual respiratory tract infections (1.77 vs 1.25 infections/year, p = 0.04) and a poorer quality of life (26 vs 14 points in the St George's Respiratory Questionnaire; p = 0.02). Low serum immunoglobulin M concentration identifies patients at risk for bronchiectasis in CVID and may play a role in pathogenesis. Bronchiectasis is relevant because it is associated with frequent respiratory tract infections, poorer lung function, a greater rate of lung function decline, and a lower quality of life

    Mangarara Formation: exhumed remnants of a middle Miocene, temperate carbonate, submarine channel-fan system on the eastern margin of Taranaki Basin, New Zealand

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    The middle Miocene Mangarara Formation is a thin (1–60 m), laterally discontinuous unit of moderately to highly calcareous (40–90%) facies of sandy to pure limestone, bioclastic sandstone, and conglomerate that crops out in a few valleys in North Taranaki across the transition from King Country Basin into offshore Taranaki Basin. The unit occurs within hemipelagic (slope) mudstone of Manganui Formation, is stratigraphically associated with redeposited sandstone of Moki Formation, and is overlain by redeposited volcaniclastic sandstone of Mohakatino Formation. The calcareous facies of the Mangarara Formation are interpreted to be mainly mass-emplaced deposits having channelised and sheet-like geometries, sedimentary structures supportive of redeposition, mixed environment fossil associations, and stratigraphic enclosure within bathyal mudrocks and flysch. The carbonate component of the deposits consists mainly of bivalves, larger benthic foraminifers (especially Amphistegina), coralline red algae including rhodoliths (Lithothamnion and Mesophyllum), and bryozoans, a warm-temperate, shallow marine skeletal association. While sediment derivation was partly from an eastern contemporary shelf, the bulk of the skeletal carbonate is inferred to have been sourced from shoal carbonate factories around and upon isolated basement highs (Patea-Tongaporutu High) to the south. The Mangarara sediments were redeposited within slope gullies and broad open submarine channels and lobes in the vicinity of the channel-lobe transition zone of a submarine fan system. Different phases of sediment transport and deposition (lateral-accretion and aggradation stages) are identified in the channel infilling. Dual fan systems likely co-existed, one dominating and predominantly siliciclastic in nature (Moki Formation), and the other infrequent and involving the temperate calcareous deposits of Mangarara Formation. The Mangarara Formation is an outcrop analogue for middle Miocene-age carbonate slope-fan deposits elsewhere in subsurface Taranaki Basin, New Zealand

    Conformal Symmetry for General Black Holes

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    We show that the warp factor of a generic asymptotically flat black hole in five dimensions can be adjusted such that a conformal symmetry emerges. The construction preserves all near horizon properties of the black holes, such as the thermodynamic potentials and the entropy. We interpret the geometry with modified asymptotic behavior as the "bare" black hole, with the ambient flat space removed. Our warp factor subtraction generalizes hidden conformal symmetry and applies whether or not rotation is significant. We also find a relation to standard AdS/CFT correspondence by embedding the black holes in six dimensions. The asymptotic conformal symmetry guarantees a dual CFT description of the general rotating black holes.Comment: 26 page

    The Rx for Change database: a first-in-class tool for optimal prescribing and medicines use

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    <p>Abstract</p> <p>Background</p> <p>Globally, suboptimal prescribing practices and medication errors are common. Guidance to health professionals and consumers alone is not sufficient to optimise behaviours, therefore strategies to promote evidence-based decision making and practice, such as decision support tools or reminders, are important. The literature in this area is growing, but is of variable quality and dispersed across sources, which makes it difficult to identify, access, and assess. To overcome these problems, by synthesizing and evaluating the data from systematic reviews, we have developed <it>Rx for Change </it>to provide a comprehensive, online database of the evidence for strategies to improve drug prescribing and use.</p> <p>Methods</p> <p>We use reliable and valid methods to search and screen the literature, and to appraise and analyse the evidence from relevant systematic reviews. We then present the findings in an online format which allows users to easily access pertinent information related to prescribing and medicines use. The database is a result of the collaboration between the Canadian Agency for Drugs and Technologies in Health (CADTH) and two Cochrane review groups.</p> <p>Results</p> <p>To capture the body of evidence on interventions to improve prescribing and medicines use, we conduct comprehensive and regular searches in multiple databases, and hand-searches of relevant journals. We screen articles to identify relevant systematic reviews, and include them if they are of moderate or high methodological quality. Two researchers screen, assess quality, and extract data on demographic details, intervention characteristics, and outcome data. We report the results of our analysis of each systematic review using a standardised quantitative and qualitative format. <it>Rx for Change </it>currently contains over 200 summarised reviews, structured in a multi-level format. The reviews included in the database are diverse, covering various settings, conditions, or diseases and targeting a range of professional and consumer behaviors.</p> <p>Conclusions</p> <p><it>Rx for Change </it>is a novel database that synthesizes current research evidence about the effects of interventions to improve drug prescribing practices and medicines use.</p

    GeoDesc: Learning Local Descriptors by Integrating Geometry Constraints

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    Learned local descriptors based on Convolutional Neural Networks (CNNs) have achieved significant improvements on patch-based benchmarks, whereas not having demonstrated strong generalization ability on recent benchmarks of image-based 3D reconstruction. In this paper, we mitigate this limitation by proposing a novel local descriptor learning approach that integrates geometry constraints from multi-view reconstructions, which benefits the learning process in terms of data generation, data sampling and loss computation. We refer to the proposed descriptor as GeoDesc, and demonstrate its superior performance on various large-scale benchmarks, and in particular show its great success on challenging reconstruction tasks. Moreover, we provide guidelines towards practical integration of learned descriptors in Structure-from-Motion (SfM) pipelines, showing the good trade-off that GeoDesc delivers to 3D reconstruction tasks between accuracy and efficiency.Comment: Accepted to ECCV'1

    Signal intensity enhancement of laser ablated volume holograms

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    Conventional volume holographic gratings (VHGs) fabricated in photosensitive emulsions such as gelatin containing silver salts enable the facile visualisation of the holographic image in ambient lighting. However, for the fabrication of holographic sensors, which require more defined and chemically-functionalised polymer matrices, laser ablation has been introduced to create the VHGs and thereby broaden their applications, although the replay signal can be challenging to detect in ambient lighting. When traditional photochemical bleaching solutions used to reduce light scattering and modulate refractive index within the VHG are applied to laser ablated volume holographic gratings, these procedures decrease the holographic peak intensity. This is postulated to occur because both light and dark fringes contain a proportion of metal particles, which upon solubilisation are converted immediately to silver iodide, yielding no net refractive index modulation. This research advances a hypothesis that the reduced intensity of holographic replay signals is linked to a gradient of different sized metal particles within the emulsion, which reduces the holographic signal and may explain why traditional bleaching processes result in a reduction in intensity. In this report, a novel experimental protocol is provided, along with simulations based on an effective medium periodic 1D stack, that offers a solution to increase peak signal intensity of holographic sensors by greater than 200%. Nitric acid is used to etch the silver nanoparticles within the polymer matrix and is thought to remove the smaller particles to generate more defined metal fringes containing a soluble metal salt. Once the grating efficiency has been increased, this salt can be converted to a silver halide, to modulate the refractive index and increase the intensity of the holographic signal. This new protocol has been tested in a range of polymer chemistries; those containing functional groups that help to stabilise the metal nanoparticles within the matrix yield more intense holographic signals as the integrity of the fringe is more protected with increasing metal solubility.EPSRC Integrated Photonics and Electronic Systems (Grant number: EP/L015455/1) Centre for Doctoral Training
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