92 research outputs found

    The 'weight of evidence' concerning tobacco harm: beliefs in mid-twentieth century America

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    We present a version of Chern et al.'s (1995) Bayesian model of `health risk belief' to track the evolution of the `weight' of epidemiological evidence concerning tobacco harm that was in the possession of the U.S. Tobacco Industry Research Committee (T.I.R.C.) and the U.S. Public Health Service and related groups during the 1950s and early 1960s. We compare our results with public statements assessing the evidence that were made by the organisations during the same period. The results from the models for the U.S. Public Health Service and related groups are not in disagreement with the public statements of these organisations; the results from the lung cancer model for the T.I.R.C. are in disagreement with the assessments of the evidence made by the T.I.R.C.'s Scientific Director in his annual reports. We discuss possible reasons for this, relating our findings to present-day academic and legal debates about the `controversy' surrounding tobacco harm during the mid-twentieth century.

    Local Wisdom in Regenerative Teacher Practices

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    In this article, teacher professional practice is conceptualised within a regenerative framing as a synthesis of intercultural perspectives drawn from wisdom traditions, placing ethics-in-action alongside reflection-in-action. Regenerative practice foregrounds the need for renewal connecting professional learning with lifelong learning. Global sustainability agendas also inform this endeavour, reminding us of our connectedness within living ecosystems while ‘local wisdom’ is considered a primary source to inspire regeneration. Ecological models of education are therefore explored to determine the nature and scope of regenerative practices. Isolation imposed by the global pandemic provided opportunity to reflect upon our own practices and how these inter-relational constructs, often at odds with competency-based requirements, might nevertheless be integrated into teacher professional development. Three layers of regenerative practice, ‘being with ourselves’, ‘being with nature’ and ‘being with each other’ are presented as integral to a holistic approach that can be aligned with and supported by teacher professional standards

    Mechanical modeling of initiation of localized yielding under plane stress conditions in rigid-rigid polymer alloys

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    Two-dimensional Finite Element Method simulations, which involve consideration of the nonlinearity of a material, have been conducted to gain understanding about the rigid-rigid polymer toughening concept we proposed. The simulation results for the plane stress condition indicate that as long as the inclusion phase possesses (i) a 60% difference in the tangent modulus from that of the matrix at any given strain level prior to failure or (ii) smaller yield or craze stain than the yield strain of the matrix, then, localized shear yielding will occur around the inclusion. A toughened rigid-rigid polymer alloy system can then be obtained. The plain strain case is also discussed with an implementation of the rigid-rigid polymer toughening concept.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38110/1/760311106_ftp.pd

    Experiences of hospital care for people with multiple long-term conditions: a scoping review of qualitative research

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    Background Multiple long-term conditions—the co-existence of two or more chronic health conditions in an individual—present an increasing challenge to populations and healthcare systems worldwide. This challenge is keenly felt in hospital settings where care is oriented around specialist provision for single conditions. The aim of this scoping review was to identify and summarise published qualitative research on the experiences of hospital care for people living with multiple long-term conditions, their informal caregivers and healthcare professionals. Methods We undertook a scoping review, following established guidelines, of primary qualitative research on experiences of hospital care for people living with multiple long-term conditions published in peer-reviewed journals between Jan 2010 and June 2022. We conducted systematic electronic searches of MEDLINE, CINAHL, PsycInfo, Proquest Social Science Premium, Web of Science, Scopus and Embase, supplemented by citation tracking. Studies were selected for inclusion by two reviewers using an independent screening process. Data extraction included study populations, study design, findings and author conclusions. We took a narrative approach to reporting the findings. Results Of 8002 titles and abstracts screened, 54 papers reporting findings from 41 studies conducted in 14 countries were identified as eligible for inclusion. The perspectives of people living with multiple long-term conditions (21 studies), informal caregivers (n = 13) and healthcare professionals (n = 27) were represented, with 15 studies reporting experiences of more than one group. Findings included poor service integration and lack of person-centred care, limited confidence of healthcare professionals to treat conditions outside of their specialty, and time pressures leading to hurried care transitions. Few studies explored inequities in experiences of hospital care. Conclusions Qualitative research evidence on the experiences of hospital care for multiple long-term conditions illuminates a tension between the desire to provide and receive person-centred care and time pressures inherent within a target-driven system focussed on increasing specialisation, reduced inpatient provision and accelerated journeys through the care system. A move towards more integrated models of care may enable the needs of people living with multiple long-term conditions to be better met. Future research should address how social circumstances shape experiences of care

    Cells activated for wound repair have the potential to direct collective invasion of an epithelium.

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    Mechanisms regulating how groups of cells are signaled to move collectively from their original site and invade surrounding matrix are poorly understood. Here we develop a clinically relevant ex vivo injury invasion model to determine whether cells involved in directing wound healing have invasive function and whether they can act as leader cells to direct movement of a wounded epithelium through a three-dimensional (3D) extracellular matrix (ECM) environment. Similar to cancer invasion, we found that the injured cells invade into the ECM as cords, involving heterotypical cell-cell interactions. Mesenchymal cells with properties of activated repair cells that typically locate to a wound edge are present in leader positions at the front of ZO-1-rich invading cords of cells, where they extend vimentin intermediate filament-enriched protrusions into the 3D ECM. Injury-induced invasion depends on both vimentin cytoskeletal function and MMP-2/9 matrix remodeling, because inhibiting either of these suppressed invasion. Potential push and pull forces at the tips of the invading cords were revealed by time-lapse imaging, which showed cells actively extending and retracting protrusions into the ECM. This 3D injury invasion model can be used to investigate mechanisms of leader cell-directed invasion and understand how mechanisms of wound healing are hijacked to cause disease

    Discovery and fine-mapping of adiposity loci using high density imputation of genome-wide association studies in individuals of African ancestry: African Ancestry Anthropometry Genetics Consortium

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    Genome-wide association studies (GWAS) have identified >300 loci associated with measures of adiposity including body mass index (BMI) and waist-to-hip ratio (adjusted for BMI, WHRadjBMI), but few have been identified through screening of the African ancestry genomes. We performed large scale meta-analyses and replications in up to 52,895 individuals for BMI and up to 23,095 individuals for WHRadjBMI from the African Ancestry Anthropometry Genetics Consortium (AAAGC) using 1000 Genomes phase 1 imputed GWAS to improve coverage of both common and low frequency variants in the low linkage disequilibrium African ancestry genomes. In the sex-combined analyses, we identified one novel locus (TCF7L2/HABP2) for WHRadjBMI and eight previously established loci at P < 5×10−8: seven for BMI, and one for WHRadjBMI in African ancestry individuals. An additional novel locus (SPRYD7/DLEU2) was identified for WHRadjBMI when combined with European GWAS. In the sex-stratified analyses, we identified three novel loci for BMI (INTS10/LPL and MLC1 in men, IRX4/IRX2 in women) and four for WHRadjBMI (SSX2IP, CASC8, PDE3B and ZDHHC1/HSD11B2 in women) in individuals of African ancestry or both African and European ancestry. For four of the novel variants, the minor allele frequency was low (<5%). In the trans-ethnic fine mapping of 47 BMI loci and 27 WHRadjBMI loci that were locus-wide significant (P < 0.05 adjusted for effective number of variants per locus) from the African ancestry sex-combined and sex-stratified analyses, 26 BMI loci and 17 WHRadjBMI loci contained ≤ 20 variants in the credible sets that jointly account for 99% posterior probability of driving the associations. The lead variants in 13 of these loci had a high probability of being causal. As compared to our previous HapMap imputed GWAS for BMI and WHRadjBMI including up to 71,412 and 27,350 African ancestry individuals, respectively, our results suggest that 1000 Genomes imputation showed modest improvement in identifying GWAS loci including low frequency variants. Trans-ethnic meta-analyses further improved fine mapping of putative causal variants in loci shared between the African and European ancestry populations

    Influence of particle size and particle size distribution on toughening mechanisms in rubber-modified epoxies

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    The principal toughening mechanism of a substantially toughened, rubber-modified epoxy has again been shown to involve internal cavitation of the rubber particles and the subsequent formation of shear bands. Additional evidence supporting this sequence of events which provides a significant amount of toughness enhancement, is presented. However, in addition to this well-known mechanism, more subtle toughening mechanisms have been found in this work. Evidence for such mechanisms as crack deflection and particle bridging is shown under certain circumstances in rubber-modified epoxies. The occurrence of these toughening mechanisms appears to have a particle size dependence. Relatively large particles provide only a modest increase in fracture toughness by a particle bridging/crack deflection mechanism. In contrast, smaller particles provide a significant increase in toughness by cavitation-induced shear banding. A critical, minimum diameter for particles which act as bridging particles exists and this critical diameter appears to scale with the properties of the neat epoxy. Bimodal mixtures of epoxies containing small and large particles are also examined and no synergistic effects are observed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44701/1/10853_2005_Article_BF01184979.pd
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