36 research outputs found

    Assessing the outcomes of participatory research: protocol for identifying, selecting, appraising and synthesizing the literature for realist review

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    <p>Abstract</p> <p>Background</p> <p>Participatory Research (PR) entails the co-governance of research by academic researchers and end-users. End-users are those who are affected by issues under study (<it>e.g.</it>, community groups or populations affected by illness), or those positioned to act on the knowledge generated by research (<it>e.g.</it>, clinicians, community leaders, health managers, patients, and policy makers). Systematic reviews assessing the generalizable benefits of PR must address: the diversity of research topics, methods, and intervention designs that involve a PR approach; varying degrees of end-user involvement in research co-governance, both within and between projects; and the complexity of outcomes arising from long-term partnerships.</p> <p>Methods</p> <p>We addressed the above mentioned challenges by adapting realist review methodology to PR assessment, specifically by developing inductively-driven identification, selection, appraisal, and synthesis procedures. This approach allowed us to address the non-uniformity and complexity of the PR literature. Each stage of the review involved two independent reviewers and followed a reproducible, systematic coding and retention procedure. Retained studies were completed participatory health interventions, demonstrated high levels of participation by non-academic stakeholders (<it>i.e.</it>, excluding studies in which end-users were not involved in co-governing throughout the stages of research) and contained detailed descriptions of the participatory process and context. Retained sets are being mapped and analyzed using realist review methods.</p> <p>Results</p> <p>The librarian-guided search string yielded 7,167 citations. A total of 594 citations were retained after the identification process. Eighty-three papers remained after selection. Principle Investigators (PIs) were contacted to solicit all companion papers. Twenty-three sets of papers (23 PR studies), comprising 276 publications, passed appraisal and are being synthesized using realist review methods.</p> <p>Discussion</p> <p>The systematic and stage-based procedure addressed challenges to PR assessment and generated our robust understanding of complex and heterogeneous PR practices. To date, realist reviews have focussed on evaluations of relatively uniform interventions. In contrast our PR search yielded a wide diversity of partnerships and research topics. We therefore developed tools to achieve conceptual clarity on the PR field, as a beneficial precursor to our theoretically-driven synthesis using realist methods. Findings from the ongoing review will be provided in forthcoming publications.</p

    Aerosol indirect effects

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    Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterises aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth (tau a) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. cloud droplet number concentration (N d) compares relatively well to the satellite data at least over the ocean. The relationship between (tau a) and liquid water path is simulated much too strongly by the models. This suggests that the implementation of the second aerosol indirect effect mainly in terms of an autoconversion parameterisation has to be revisited in the GCMs. A positive relationship between total cloud fraction (fcld) and tau a as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the satellite data in most of them. In a discussion of the hypotheses proposed in the literature to explain the satellite-derived strong fcld–tau a relationship, our results indicate that none can be identified as a unique explanation. Relationships similar to the ones found in satellite data between tau a and cloud top temperature or outgoing long-wave radiation (OLR) are simulated by only a few GCMs. The GCMs that simulate a negative OLR - tau a relationship show a strong positive correlation between tau a and fcld. The short-wave total aerosol radiative forcing as simulated by the GCMs is strongly influenced by the simulated anthropogenic fraction of tau a, and parameterisation assumptions such as a lower bound on Nd. Nevertheless, the strengths of the statistical relationships are good predictors for the aerosol forcings in the models. An estimate of the total short-wave aerosol forcing inferred from the combination of these predictors for the modelled forcings with the satellite-derived statistical relationships yields a global annual mean value of −1.5±0.5Wm−2. In an alternative approach, the radiative flux perturbation due to anthropogenic aerosols can be broken down into a component over the cloud-free portion of the globe (approximately the aerosol direct effect) and a component over the cloudy portion of the globe (approximately the aerosol indirect effect). An estimate obtained by scaling these simulated clearand cloudy-sky forcings with estimates of anthropogenic tau a and satellite-retrieved Nd–tau a regression slopes, respectively, yields a global, annual-mean aerosol direct effect estimate of −0.4±0.2Wm−2 and a cloudy-sky (aerosol indirect effect) estimate of −0.7±0.5Wm−2, with a total estimate of −1.2±0.4Wm−2

    Coding variants in RPL3L and MYZAP increase risk of atrial fibrillation

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    Source at https://doi.org/10.1038/s42003-018-0068-9. Most sequence variants identified hitherto in genome-wide association studies (GWAS) of atrial fibrillation are common, non-coding variants associated with risk through unknown mechanisms. We performed a meta-analysis of GWAS of atrial fibrillation among 29,502 cases and 767,760 controls from Iceland and the UK Biobank with follow-up in samples from Norway and the US, focusing on low-frequency coding and splice variants aiming to identify causal genes. We observe associations with one missense (OR = 1.20) and one splice-donor variant (OR = 1.50) in RPL3L, the first ribosomal gene implicated in atrial fibrillation to our knowledge. Analysis of 167 RNA samples from the right atrium reveals that the splice-donor variant in RPL3L results in exon skipping. We also observe an association with a missense variant in MYZAP (OR = 1.38), encoding a component of the intercalated discs of cardiomyocytes. Both discoveries emphasize the close relationship between the mechanical and electrical function of the heart

    Jaundice due to suspected statin hepatotoxicity: a case series.

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    Statin drugs are widely used worldwide and are generally considered safe and well tolerated. Only small proportion of patients receiving statins develop elevations of liver enzymes and an even smaller proportion will have clinically significant hepatitis induced by statins. We describe four patients with jaundice caused by drug-induced liver injury, where the most likely agent was a statin drug, over a period of approximately three year in Iceland. We calculate the risk of jaundice caused by statin drugs, from sale in the whole country of Iceland, to be one in 17,434 users a year. This is a higher risk than has previously been estimated and we challenge the current opinion that statins rarely cause clinically significant drug-induced liver injury and encourage alertness when managing patients with statins with regard to clinical signs of hepatitis before jaundice occurs

    Aerosol-cloud interaction inferred from MODIS satellite data and global aerosol models

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    We have used the MODIS satellite data and two global aerosol models to investigate the relationships between aerosol optical depth (AOD) and cloud parameters that may be affected by the aerosol concentration. The relationships that are studied are mainly between AOD, on the one hand, and cloud cover, cloud liquid water path, and water vapour, on the other. Additionally, cloud droplet effective radius, cloud optical depth, cloud top pressure and aerosol Ångström exponent, have been analysed in a few cases. In the MODIS data we found, as in earlier studies, an enhancement in the cloud cover with increasing AOD. We find it likely that most of the strong increase in cloud cover with AOD, at least for AOD0.2 can be explained by larger water uptake close to the clouds since relative humidity is higher in regions with higher cloud cover. The efficiency of the hygroscopic growth depends on aerosol type, the hygroscopic nature of the aerosol, the relative humidity, and to some extent the cloud screening. By analysing the Ångström exponent we find that the hygroscopic growth of the aerosol is not likely to be a main contributor to the cloud cover increase with AOD. Since the largest increase in cloud cover with AOD is for low AOD (~0.2) and thus also for low cloud cover, we argue that cloud contamination is not likely to play a large role. However, interpretation of the complex relationships between AOD and cloud parameters should be made with great care and further work is clearly needed

    Modification of linear (β1→3)-linked gluco-oligosaccharides with a novel recombinant β-glucosyltransferase (trans-β-glucosidase) enzyme from Bradyrhizobium diazoefficiens

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    Recently, we have shown that glycoside hydrolases enzymes of family GH17 from proteobacteria (genera Pseudomonas, Azotobacter) catalyze elongation transfer reactions with laminari-oligosaccharides generating (β1→3) linkages preferably and to a lesser extent (β1→6) or (β1→4) linkages. In the present study, the cloning and characterization of the gene encoding the structurally very similar GH17 domain of the NdvB enzyme from Bradyrhizobium diazoefficiens, designated Glt20, as well as its catalytic properties are described. The Glt20 enzyme was strikingly different from the previously investigated bacterial GH17 enzymes, both regarding substrate specificity and product formation. The Azotobacter and Pseudomonas enzymes cleaved the donor laminari-oligosaccharide substrates three or four moieties from the non-reducing end, generating linear oligosaccharides. In contrast, the Glt20 enzyme cleaved donor laminari-oligosaccharide substrates two glucose moieties from the reducing end, releasing laminaribiose and transferring the remainder to laminari-oligosaccharide acceptor substrates creating only (β1→3)(β1→6) branching points. This enables Glt20 to transfer larger oligosaccharide chains than the other type of bacterial enzymes previously described, and helps explain the biologically significant formation of cyclic β-glucans in B. diazoefficiens
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