109 research outputs found

    The NiSi melting curve to 70 GPa

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    The melting curve of NiSi has been determined to 70 GPa on the basis of laser-heated diamond anvil cell (LH-DAC) experiments in which changes in the gradient of temperature vs. laser power functions were used as the melting criterion. The melting curve was corroborated with in situ X-ray diffraction experiments in both the LH-DAC and multi-anvil press in which the appearance of liquid diffuse scattering in the diffraction patterns was used as the melting criterion. At all pressures, the NiSi melting curve is lower than that of FeSi, with the difference in melting temperature reaching a maximum of 900 K at 14 GPa. The location of the B31 + B20 + L triple point has been constrained to 12 ± 2 GPa and 1550 ± 100 K and the B20 + B2 + L triple point to 28.5 ± 1.5 GPa and 2165 ± 60 K. On the basis of the in situ LH-DAC experiments the Clapeyron slope of the B20 → B2 transition is estimated at −67 MPa K−1. Extrapolation of the B2-NiSi liquidus to core-mantle boundary (CMB) conditions (135 GPa) suggests the melting point of NiSi (3700 ± 400 K) will be only marginally lower than that of isostructural FeSi (4000 ± 200 K). Thus any (Fe,Ni)Si solid solution present within the D″ layer is expected to remain solid, with the possible exception of the very hottest region adjacent to the CMB

    Providing education on evidence-based practice improved knowledge but did not change behaviour: a before and after study

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    BACKGROUND: Many health professionals lack the skills to find and appraise published research. This lack of skills and associated knowledge needs to be addressed, and practice habits need to change, for evidence-based practice to occur. The aim of this before and after study was to evaluate the effect of a multifaceted intervention on the knowledge, skills, attitudes and behaviour of allied health professionals. METHODS: 114 self-selected occupational therapists were recruited. The intervention included a 2-day workshop combined with outreach support for eight months. Support involved email and telephone contact and a workplace visit. Measures were collected at baseline, post-workshop, and eight months later. The primary outcome was knowledge, measured using the Adapted Fresno Test of Evidence-Based Practice (total score 0 to 156). Secondary outcomes were attitude to evidence-based practice (% reporting improved skills and confidence; % reporting barriers), and behaviour measured using an activity diary (% engaging/not engaging in search and appraisal activities), and assignment completion. RESULTS: Post-workshop, there were significant gains in knowledge which were maintained at follow-up. The mean difference in the Adapted Fresno Test total score was 20.6 points (95% CI, 15.6 to 25.5). The change from post-workshop to follow-up was small and non-significant (mean difference 1.2 points, 95% CI, -6.0 to 8.5). Fewer participants reported lack of searching and appraisal skills as barriers to evidence-based practice over time (searching = 61%, 53%, 24%; appraisal 60%, 65%, 41%). These differences were statistically significant (p = 0.0001 and 0.010 respectively). Behaviour changed little. Pre-workshop, 6% engaged in critical appraisal increasing to 18% post-workshop and 18% at follow-up. Nearly two thirds (60%) were not reading any research literature at follow-up. Twenty-three participants (20.2%) completed their assignment. CONCLUSION: Evidence-based practice skills and knowledge improved markedly with a targetted education intervention and outreach support. However, changes in behaviour were small, based on the frequency of searching and appraisal activities. Allied health educators should focus more on post-workshop skill development, particularly appraisal, and help learners to establish new routines and priorities around evidence-based practice. Learners also need to know that behaviour change of this nature may take months, even years

    A genome-wide association meta-analysis on lipoprotein (a) concentrations adjusted for apolipoprotein (a) isoforms

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    High lipoprotein (a) [Lp(a)] concentrations are an independent risk factor for cardiovascular outcomes. Concentrations are strongly influenced by apo(a) kringle IV repeat isoforms. We aimed to identify genetic loci associated with Lp(a) concentrations using data from five genome- wide association studies (n = 13,781). We identified 48 independent SNPs in the LPA and 1 SNP in the APOE gene region to be significantly associated with Lp(a) concentrations. We also adjusted for apo(a) isoforms to identify loci affecting Lp(a) levels independently from them, which resulted in 31 SNPs (30 in the LPA, 1 in the APOE gene region). Seve

    A randomized controlled trial evaluating the impact of knowledge translation and exchange strategies

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    Nothing Lasts Forever: Environmental Discourses on the Collapse of Past Societies

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    The study of the collapse of past societies raises many questions for the theory and practice of archaeology. Interest in collapse extends as well into the natural sciences and environmental and sustainability policy. Despite a range of approaches to collapse, the predominant paradigm is environmental collapse, which I argue obscures recognition of the dynamic role of social processes that lie at the heart of human communities. These environmental discourses, together with confusion over terminology and the concepts of collapse, have created widespread aporia about collapse and resulted in the creation of mixed messages about complex historical and social processes

    Author Correction: Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases

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    Emmanuelle Souzeau, who contributed to analysis of data, was inadvertently omitted from the author list in the originally published version of this Article. This has now been corrected in both the PDF and HTML versions of the Article

    Gene-educational attainment interactions in a multi-population genome-wide meta-analysis identify novel lipid loci

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    A "Candidate-Interactome" Aggregate Analysis of Genome-Wide Association Data in Multiple Sclerosis

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    Though difficult, the study of gene-environment interactions in multifactorial diseases is crucial for interpreting the relevance of non-heritable factors and prevents from overlooking genetic associations with small but measurable effects. We propose a “candidate interactome” (i.e. a group of genes whose products are known to physically interact with environmental factors that may be relevant for disease pathogenesis) analysis of genome-wide association data in multiple sclerosis. We looked for statistical enrichment of associations among interactomes that, at the current state of knowledge, may be representative of gene-environment interactions of potential, uncertain or unlikely relevance for multiple sclerosis pathogenesis: Epstein-Barr virus, human immunodeficiency virus, hepatitis B virus, hepatitis C virus, cytomegalovirus, HHV8-Kaposi sarcoma, H1N1-influenza, JC virus, human innate immunity interactome for type I interferon, autoimmune regulator, vitamin D receptor, aryl hydrocarbon receptor and a panel of proteins targeted by 70 innate immune-modulating viral open reading frames from 30 viral species. Interactomes were either obtained from the literature or were manually curated. The P values of all single nucleotide polymorphism mapping to a given interactome were obtained from the last genome-wide association study of the International Multiple Sclerosis Genetics Consortium & the Wellcome Trust Case Control Consortium, 2. The interaction between genotype and Epstein Barr virus emerges as relevant for multiple sclerosis etiology. However, in line with recent data on the coexistence of common and unique strategies used by viruses to perturb the human molecular system, also other viruses have a similar potential, though probably less relevant in epidemiological terms

    A Large-Scale Multi-ancestry Genome-wide Study Accounting for Smoking Behavior Identifies Multiple Significant Loci for Blood Pressure

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    Genome-wide association analysis advanced understanding of blood pressure (BP), a major risk factor for vascular conditions such as coronary heart disease and stroke. Accounting for smoking behavior may help identify BP loci and extend our knowledge of its genetic architecture. We performed genome-wide association meta-analyses of systolic and diastolic BP incorporating gene-smoking interactions in 610,091 individuals. Stage 1 analysis examined similar to 18.8 million SNPs and small insertion/deletion variants in 129,913 individuals from four ancestries (European, African, Asian, and Hispanic) with follow-up analysis of promising variants in 480,178 additional individuals from five ancestries. We identified 15 loci that were genome-wide significant (p <5 x 10(-8)) in stage 1 and formally replicated in stage 2. A combined stage 1 and 2 meta-analysis identified 66 additional genome-wide significant loci (13, 35, and 18 loci in European, African, and trans-ancestry, respectively). A total of 56 known BP loci were also identified by our results (p <5 x 10(-8)). Of the newly identified loci, ten showed significant interaction with smoking status, but none of them were replicated in stage 2. Several loci were identified in African ancestry, highlighting the importance of genetic studies in diverse populations. The identified loci show strong evidence for regulatory features and support shared pathophysiology with cardiometabolic and addiction traits. They also highlight a role in BP regulation for biological candidates such as modulators of vascular structure and function (CDKN1B, BCAR1-CFDP1, PXDN, EEA1), ciliopathies (SDCCAG8, RPGRIP1L), telomere maintenance (TNKS, PINX1, AKTIP), and central dopaminergic signaling MSRA, EBF2).Peer reviewe
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