278 research outputs found

    Quasi-Elastic Scattering Studies of Water Diffusion

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    Quasi-elastic neutron scattering is a powerful method to study the dynamics of protons in biological systems. The technique has been used both for the study of water diffusion and protein motion. The neutron scattering measurements on water show that the translational and rotational diffusion coefficients in biological systems are reduced from bulk values. We review the measurements on water in frog muscle, cysts of artemia, and phycocyanin. Measurements on dry trypsin and trypsin-D2O solutions over the temperature range 75-300K show that there is proton motion at the one angstrom level even in the dry or frozen state

    Twisted k-graph algebras associated to Bratteli diagrams

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    Given a system of coverings of k-graphs, we show that the cohomology of the resulting (k+1)-graph is isomorphic to that of any one of the k-graphs in the system. We then consider Bratteli diagrams of 2-graphs whose twisted C*-algebras are matrix algebras over noncommutative tori. For such systems we calculate the ordered K-theory and the gauge-invariant semifinite traces of the resulting 3-graph C*-algebras. We deduce that every simple C*-algebra of this form is Morita equivalent to the C*-algebra of a rank-2 Bratteli diagram in the sense of Pask-Raeburn-R{\o}rdam-Sims.Comment: 28 pages, pictures prepared using tik

    A uniform asteroseismic analysis of 22 solar-type stars observed by Kepler

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    Asteroseismology with the Kepler space telescope is providing not only an improved characterization of exoplanets and their host stars, but also a new window on stellar structure and evolution for the large sample of solar-type stars in the field. We perform a uniform analysis of 22 of the brightest asteroseismic targets with the highest signal-to-noise ratio observed for 1 month each during the first year of the mission, and we quantify the precision and relative accuracy of asteroseismic determinations of the stellar radius, mass, and age that are possible using various methods. We present the properties of each star in the sample derived from an automated analysis of the individual oscillation frequencies and other observational constraints using the Asteroseismic Modeling Portal (AMP), and we compare them to the results of model-grid-based methods that fit the global oscillation properties. We find that fitting the individual frequencies typically yields asteroseismic radii and masses to \sim1% precision, and ages to \sim2.5% precision (respectively 2, 5, and 8 times better than fitting the global oscillation properties). The absolute level of agreement between the results from different approaches is also encouraging, with model-grid-based methods yielding slightly smaller estimates of the radius and mass and slightly older values for the stellar age relative to AMP, which computes a large number of dedicated models for each star. The sample of targets for which this type of analysis is possible will grow as longer data sets are obtained during the remainder of the mission.Comment: 13 pages, 5 figures in the main text, 22 figures in Appendix. Accepted for publication in Ap

    Multi-level strategies to improve equitable timely person-centred osteoarthritis care for diverse women: qualitative interviews with women and healthcare professionals

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    Abstract Background Women are more likely to develop osteoarthritis (OA), and have greater OA pain and disability compared with men, but are less likely to receive guideline-recommended management, particularly racialized women. OA care of diverse women, and strategies to improve the quality of their OA care is understudied. The purpose of this study was to explore strategies to overcome barriers of access to OA care for diverse women. Methods We conducted qualitative interviews with key informants and used content analysis to identify themes regarding what constitutes person-centred OA care, barriers of OA care, and strategies to support equitable timely access to person-centred OA care. Results We interviewed 27 women who varied by ethno-cultural group (e.g. African or Caribbean Black, Chinese, Filipino, Indian, Pakistani, Caucasian), age, region of Canada, level of education, location of OA and years with OA; and 31 healthcare professionals who varied by profession (e.g. family physician, nurse practitioner, community pharmacist, physio- and occupational therapists, chiropractors, healthcare executives, policy-makers), career stage, region of Canada and type of organization. Participants within and across groups largely agreed on approaches for person-centred OA care across six domains: foster a healing relationship, exchange information, address emotions, manage uncertainty, share decisions and enable self-management. Participants identified 22 barriers of access and 18 strategies to overcome barriers at the patient- (e.g. educational sessions and materials that accommodate cultural norms offered in different languages and formats for persons affected by OA), healthcare professional- (e.g. medical and continuing education on OA and on providing OA care tailored to intersectional factors) and system- (e.g. public health campaigns to raise awareness of OA, and how to prevent and manage it; self-referral to and public funding for therapy, greater number and ethno-cultural diversity of healthcare professionals, healthcare policies that address the needs of diverse women, dedicated inter-professional OA clinics, and a national strategy to coordinate OA care) levels. Conclusions This research contributes to a gap in knowledge of how to optimize OA care for disadvantaged groups including diverse women. Ongoing efforts are needed to examine how best to implement these strategies, which will require multi-sector collaboration and must engage diverse women

    Quality assessment of clinical practice guidelinesfor Chagas disease

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    INTRODUCTION: The development of clinical practice guidelines (CPGs) has increased; this study aimed to assess the quality of CPGs for the management of Chagas disease. METHODS: Following a systematic search of the scientific literature, two reviewers assessed the eligible guidelines using the Appraisal of Guidelines Research and Evaluation (AGREE) II instrument. RESULTS: Five CPGs were included. The AGREE domains of scope/purpose, stakeholder involvement, and clarity of presentation were rated well, and the domains of applicability and editorial independence received poor ratings. CONCLUSIONS: The quality of CPGs for Chagas disease is poor, and significant work is required to develop high-quality guidelines
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