398 research outputs found

    An Innovative Cold-formed Floor System

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    Optimizing the use of building materials has always been one of the primary goals of engineers. It is a constant challenge to seek innovative methods to build lighter weight structures. Sometimes this is achieved through the development of new building materials, other times it can be accomplished by creating entirely new types of structural systems. Often lightweight structures can be more asthetically pleasing because of their stream-lined appearance. However, in general the motivating factor in building lightweight structures is to reduce the overall cost. One portion of a structure which offers tremendous potential for weight reduction is the floor system. The floor system is one of the heaviest components in typical steel framed buildings. A reduction in the dead load of this component will result in a subsequent reduction in the total weight of the building structural system

    "Driven to distraction?" Children's experiences of car travel

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    This is an Author's Accepted Manuscript of an article published in volume, 4, issue 1, pages 59-76 in Mobilities 2009. Copyright @ 2009 Taylor & Francis, available online at: http://www.tandfonline.com/doi/abs/10.1080/17450100802657962.Cars have become increasingly significant features in the lives of many children and adults in the UK and elsewhere. Whilst there is a growing body of research considering how adults experience automobility, that is the increasingly central role of cars within societies, there has been little equivalent research exploring children's perspectives. Drawing upon a variety of methods including personal diaries, photographs, in‐depth interviews and surveys amongst schools within Buckinghamshire and North London, the paper contributes to filling this gap in existing research through exploring how cars are not only journey spaces for children, but are also sites for play, relaxation, homework, companionship, technology and the consumption of commodities. Using a Foucauldian analysis of power, insights into wider familial processes relating to mobility are provided by exploring how cars are sites of conflicting power relations between parents and children. The paper also explores how children's everyday experiences of cars were framed by wider sets of power relations, including car corporations which design and manufacture these spaces, and the role of capital which commodifies everyday activities in cars. In doing so, the paper challenges existing research on automobility for only focusing upon adults' experiences of cars and begins to theorise a more inclusive account of automobility which incorporates children and young people

    1 m long multilayer-coated deformable piezoelectric bimorph mirror for adjustable focusing of high-energy X-rays

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    The Diamond Light Source (DLS) beamline I15-1 measures atomic pair distribution functions (PDF) using scattering of 40-80 keV X-rays. A unique focusing element was needed to condense these X-rays from an initial large cross section (11.0 mm H × 4.2 mm V) into a required spot size of FWHM ≈680 μm (H) × 20 μm (V) at a variable position between the sample and the detector. The large numerical aperture is achieved by coating a silicon substrate over 1 m long with three multilayer stripes of Bragg angle 4.2 mrad. One stripe selects X-rays of each energy 40.0, 65.4, and 76.6 keV. Sixteen piezoelectric bimorph actuators attached to the sides of the mirror substrate adjusted the reflecting surface’s shape. Focal spots of vertical width < 15 μm were obtained at three positions over a 0.92 m range, with fast, easy switching from one focal position to another. Minimized root mean square slope errors were close to 0.5 μrad after subtraction of a uniform curvature. Reflectivity curves taken along each stripe showed consistent high peaks with generally small angular variation of peak positions. This is the first application of a 1 m long multilayercoated bimorph mirror at a synchrotron beamline. Data collected with its help on a slice of a lithium ion battery’s cathode are presented

    Focused fluid seepage related to variations in accretionary wedge structure, Hikurangi margin, New Zealand

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    Hydrogeological processes influence the morphology, mechanical behavior, and evolution of subduction margins. Fluid supply, release, migration, and drainage control fluid pressure and collectively govern the stress state, which varies between accretionary and nonaccretionary systems. We compiled over a decade of published and unpublished acoustic data sets and seafloor observations to analyze the distribution of focused fluid expulsion along the Hikurangi margin, New Zealand. The spatial coverage and quality of our data are exceptional for subduction margins globally. We found that focused fluid seepage is widespread and varies south to north with changes in subduction setting, including: wedge morphology, convergence rate, seafloor roughness, and sediment thickness on the incoming Pacific plate. Overall, focused seepage manifests most commonly above the deforming backstop, is common on thrust ridges, and is largely absent from the frontal wedge despite ubiquitous hydrate occurrences. Focused seepage distribution may reflect spatial differences in shallow permeability architecture, while diffusive fluid flow and seepage at scales below detection limits are also likely. From the spatial coincidence of fluids with major thrust faults that disrupt gas hydrate stability, we surmise that focused seepage distribution may also reflect deeper drainage of the forearc, with implications for pore-pressure regime, fault mechanics, and critical wedge stability and morphology. Because a range of subduction styles is represented by 800 km of along-strike variability, our results may have implications for understanding subduction fluid flow and seepage globally

    A comprehensive model of factors associated with subjective perceptions of living well with dementia: findings from the IDEAL study

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    Background: The concept of ‘living well’ is increasingly used to indicate that it is, or should be, possible for a person living with dementia to experience a subjective sense of ‘comfort, function and contentment with life.’ We used a theoretically-derived conceptual framework to investigate capability to ‘live well’ with dementia through identifying the relative contribution of domains associated with the subjective experience of living well. Methods: We analysed data from 1550 community-dwelling individuals with mild to moderate dementia participating in the baseline wave of the Improving the experience of Dementia and Enhancing Active Life (IDEAL) cohort study. Subjective perceptions of ability to live well were obtained by generating a living well latent factor from responses on the Quality of Life in Alzheimer’s disease (QoL-AD), Satisfaction with Life and WHO-5 Well-being scales. Multivariate modelling and structural equation modelling was used to investigate variables potentially associated with living well. Variables were grouped into five domains, latent variables were constructed representing Social Location, Capitals, Assets and Resources, Psychological Characteristics and Psychological Health, Physical Fitness and Health, and Managing Everyday Life with Dementia, and associations with living well were examined. All models were adjusted for age, sex and dementia sub-type. Results: Considering the domains singly, the Psychological Characteristics and Psychological Health domain was most strongly associated with living well (3.56; 95% CI: 2.25, 4.88), followed by Physical Fitness and Physical Health (1.10, 95% CI: -2.26, 4.47). Effect sizes were smaller for Capitals, Assets and Resources (0.53; 95% CI: -0.66, 1.73), Managing Everyday Life with Dementia (0.34; 95% CI: 0.20, 0.87), and Social Location (-0.12; 95% CI: -5.72, 5.47). Following adjustment for the Psychological Characteristics and Psychological Health domain, other domains did not show independent associations with living well. Conclusions: Psychological resources are central to subjective perceptions of living well and offer important targets for immediate intervention. Availability of social and environmental resources, and physical fitness, underpin these positive psychological states, and also offer potential targets for interventions and initiatives aimed at improving the experience of living with dementia

    A comprehensive model of factors associated with subjective perceptions of living well with dementia: findings from the IDEAL study

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    Background: The concept of ‘living well’ is increasingly used to indicate that it is, or should be, possible for a person living with dementia to experience a subjective sense of ‘comfort, function and contentment with life.’ We used a theoretically-derived conceptual framework to investigate capability to ‘live well’ with dementia through identifying the relative contribution of domains associated with the subjective experience of living well. Methods: We analysed data from 1550 community-dwelling individuals with mild to moderate dementia participating in the baseline wave of the Improving the experience of Dementia and Enhancing Active Life (IDEAL) cohort study. Subjective perceptions of ability to live well were obtained by generating a living well latent factor from responses on the Quality of Life in Alzheimer’s disease (QoL-AD), Satisfaction with Life and WHO-5 Well-being scales. Multivariate modelling and structural equation modelling was used to investigate variables potentially associated with living well. Variables were grouped into five domains, latent variables were constructed representing Social Location, Capitals, Assets and Resources, Psychological Characteristics and Psychological Health, Physical Fitness and Health, and Managing Everyday Life with Dementia, and associations with living well were examined. All models were adjusted for age, sex and dementia sub-type. Results: Considering the domains singly, the Psychological Characteristics and Psychological Health domain was most strongly associated with living well (3.56; 95% CI: 2.25, 4.88), followed by Physical Fitness and Physical Health (1.10, 95% CI: -2.26, 4.47). Effect sizes were smaller for Capitals, Assets and Resources (0.53; 95% CI: -0.66, 1.73), Managing Everyday Life with Dementia (0.34; 95% CI: 0.20, 0.87), and Social Location (-0.12; 95% CI: -5.72, 5.47). Following adjustment for the Psychological Characteristics and Psychological Health domain, other domains did not show independent associations with living well. Conclusions: Psychological resources are central to subjective perceptions of living well and offer important targets for immediate intervention. Availability of social and environmental resources, and physical fitness, underpin these positive psychological states, and also offer potential targets for interventions and initiatives aimed at improving the experience of living with dementia

    Leveraging Pleiotropy to Discover and interpret Gwas Results For Sleep-Associated Traits

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    Genetic association studies of many heritable traits resulting from physiological testing often have modest sample sizes due to the cost and burden of the required phenotyping. This reduces statistical power and limits discovery of multiple genetic associations. We present a strategy to leverage pleiotropy between traits to both discover new loci and to provide mechanistic hypotheses of the underlying pathophysiology. Specifically, we combine a colocalization test with a locus-level test of pleiotropy. In simulations, we show that this approach is highly selective for identifying true pleiotropy driven by the same causative variant, thereby improves the chance to replicate the associations in underpowered validation cohorts and leads to higher interpretability. Here, as an exemplar, we use Obstructive Sleep Apnea (OSA), a common disorder diagnosed using overnight multi-channel physiological testing. We leverage pleiotropy with relevant cellular and cardio-metabolic phenotypes and gene expression traits to map new risk loci in an underpowered OSA GWAS. We identify several pleiotropic loci harboring suggestive associations to OSA and genome-wide significant associations to other traits, and show that their OSA association replicates in independent cohorts of diverse ancestries. By investigating pleiotropic loci, our strategy allows proposing new hypotheses about OSA pathobiology across many physiological layers. For example, we identify and replicate the pleiotropy across the plateletcrit, OSA and an eQTL of DNA primase subunit 1 (PRIM1) in immune cells. We find suggestive links between OSA, a measure of lung function (FEV1/FVC), and an eQTL of matrix metallopeptidase 15 (MMP15) in lung tissue. We also link a previously known genome-wide significant peak for OSA in the hexokinase 1 (HK1) locus to hematocrit and other red blood cell related traits. Thus, the analysis of pleiotropic associations has the potential to assemble diverse phenotypes into a chain of mechanistic hypotheses that provide insight into the pathogenesis of complex human diseases

    Modeling resilience and sustainability in ancient agricultural systems

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    The reasons why people adopt unsustainable agricultural practices, and the ultimate environmental implications of those practices, remain incompletely understood in the present world. Archaeology, however, offers unique datasets on coincident cultural and ecological change, and their social and environmental effects. This article applies concepts derived from ecological resilience thinking to assess the sustainability of agricultural practices as a result of long-term interactions between political, economic, and environmental systems. Using the urban center of Gordion, in central Turkey, as a case study, it is possible to identify mismatched social and ecological processes on temporal, spatial, and organizational scales, which help to resolve thresholds of resilience. Results of this analysis implicate temporal and spatial mismatches as a cause for local environmental degradation, and increasing extralocal economic pressures as an ultimate cause for the adoption of unsustainable land-use practices. This analysis suggests that a research approach that integrates environmental archaeology with a resilience perspective has considerable potential for explicating regional patterns of agricultural change and environmental degradation in the past
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