522 research outputs found

    The microscopic origin of thermal cracking in rocks: An investigation by simultaneous time-of-flight neutron diffraction and acoustic emission monitoring

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    We demonstrate that neutron diffraction measurements make it possible to quantify elastic strains within the interior of solid samples, and thus have great potential for addressing a wide range of problems connected with the characterization of the mechanical properties of geological materials. We use the time-of-flight neutron diffraction technique, in combination with acoustic emission monitoring, to study the evolution of thermal strain within the interior of samples of a pure quartzite during slow heating, and the onset of the associated thermal cracking. Thermal cracking commences around 180 degreesC when the thermal strain deficit along the a-axes of quartz grains induces a thermal stress that is close to the bulk tensile strength of the rock

    Leadership communication

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    A descriptive study of chiropractors' opinions and practices regarding office-based health product sales

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    <p>Abstract</p> <p>Background</p> <p>Although the sale of non-prescription health products is ubiquitous, the views of health professionals, such as chiropractors, regarding the sale of such products are not well known. Practitioner opinion is important to understand and inform professional practice. The purpose of this study was to describe chiropractors' perspectives and practices on the sale of health care products from practitioners' offices.</p> <p>Methods</p> <p>Chiropractors were invited to provide written comments about health product sales at the end of a fixed choice, mailed survey. Respondents' comments were analyzed using qualitative description. Ethics approval was received from the Conjoint Health Research Ethics Board at the University of Calgary.</p> <p>Results</p> <p>One hundred seven of the 265 respondents (response rate of 51%) provided written comments. Approximately 30 pages of double-spaced, typed text were gathered. Respondents did not consistently endorse or condemn health product sales, and engaged in the practice to greater and lesser extents. While some were opposed to health products sales, some accepted the practice with a degree of ambivalence whereas others clearly embraced it. Some respondents acknowledged a professional conflict of interest in such sales and marketing, and described strategies used to mitigate it. Others provided a range of justifications for the practice. Personal integrity and professional standards were discussed and a need for monitoring identified.</p> <p>Conclusions</p> <p>A wide range of opinions and practices were described and this is consistent with resulting variation in practice. In light of this, standards that facilitate consistency in practice may benefit professionals and the public alike.</p

    Developing culturally safe education practices in optometry schools across Australia and Aotearoa New Zealand

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    Access to culturally safe health services is a basic human right, however through the lasting effects of colonisation, oppression, and systemic racism, the individual and community health of Indigenous peoples in Australia and Aotearoa New Zealand have been severely impacted. The Aboriginal and Torres Strait Islander Health and Cultural Safety Strategy of the Australian Health Practitioners Regulation Agency, and the Standards of Cultural Competence and Cultural Safety of the Optometrists and Dispensing Opticians Board of New Zealand, recognise the importance of access to safe health care for Aboriginal, Torres Strait Islander and Māori patients, which encompasses both clinical competency and cultural safety. Universities have an ongoing responsibility to ensure their learning and teaching activities result in graduates being able to provide culturally safe practice. This article highlights the emergence of culturally safe practices in the Australian and Aotearoa New Zealand optometry curricula over the last five years incorporating Indigenous ways of knowing, being and doing into the curricula, understanding the local Indigenous histories and contexts, the adoption of online cultural education modules, and clinical placement partnerships with local Indigenous communities. Whilst there is still much work to do to achieve the goal of graduating culturally safe optometrists, this paper focuses on features that enable or impede progress in the development of culturally safe practices within the optometry programmes to improve eye health equity for Indigenous recognise the diversity of Indigenous cultures across Australia and NZ

    Protocol: does sodium nitrite administration reduce ischaemia-reperfusion injury in patients presenting with acute ST segment elevation myocardial infarction? Nitrites in acute myocardial infarction (NIAMI)

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    BACKGROUND: Whilst advances in reperfusion therapies have reduced early mortality from acute myocardial infarction, heart failure remains a common complication, and may develop very early or long after the acute event. Reperfusion itself leads to further tissue damage, a process described as ischaemia-reperfusion-injury (IRI), which contributes up to 50% of the final infarct size. In experimental models nitrite administration potently protects against IRI in several organs, including the heart. In the current study we investigate whether intravenous sodium nitrite administration immediately prior to percutaneous coronary intervention (PCI) in patients with acute ST segment elevation myocardial infarction will reduce myocardial infarct size. This is a phase II, randomised, placebo-controlled, double-blinded and multicentre trial. METHODS AND OUTCOMES: The aim of this trial is to determine whether a 5 minute systemic injection of sodium nitrite, administered immediately before opening of the infarct related artery, results in significant reduction of IRI in patients with first acute ST elevation myocardial infarction (MI). The primary clinical end point is the difference in infarct size between sodium nitrite and placebo groups measured using cardiovascular magnetic resonance imaging (CMR) performed at 6-8 days following the AMI and corrected for area at risk (AAR) using the endocardial surface area technique. Secondary end points include (i) plasma creatine kinase and Troponin I measured in blood samples taken pre-injection of the study medication and over the following 72 hours; (ii) infarct size at six months; (iii) Infarct size corrected for AAR measured at 6-8 days using T2 weighted triple inversion recovery (T2-W SPAIR or STIR) CMR imaging; (iv) Left ventricular (LV) ejection fraction measured by CMR at 6-8 days and six months following injection of the study medication; and (v) LV end systolic volume index at 6-8 days and six months. FUNDING,ETHICS AND REGULATORY APPROVALS: This study is funded by a grant from the UK Medical Research Council. This protocol is approved by the Scotland A Research Ethics Committee and has also received clinical trial authorisation from the Medicines and Healthcare products Regulatory Agency (MHRA) (EudraCT number: 2010-023571-26)

    Antibodies Against Human BLyS and APRIL Attenuate EAE Development in Marmoset Monkeys

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    B lymphocyte stimulator (BLyS, also indicated as BAFF (B-cell activating factor) and CD257), and A Proliferation Inducing Ligand (APRIL, CD256) are two members of the TNF superfamily with a central role in B cell survival. Antibodies against these factors have potential therapeutic relevance in autoimmune inflammatory disorders with a proven pathogenic contribution of B cells, such as multiple sclerosis (MS). In the current study we performed a multi-parameter efficacy comparison of monoclonal antibodies against human anti-BLyS and anti-APRIL in a common marmoset (Callithrix jacchus) model of experimental autoimmune encephalomyelitis (EAE). A MS-like disease was induced by immunization with recombinant human myelin/oligodendrocyte glycoprotein (rhMOG) in complete Freund's adjuvant. The results show that the anti-BLyS and anti-APRIL antibody cause significant depletion of circulating CD20+ B cells, but a small subset of CD20 + CD40highB cells was not depleted. Induction of CD20+ B cell depletion from lymph nodes was only observed in the anti-BLyS treated monkeys. Both antibodies had a significant inhibitory effect on disease development, but all monkeys developed clinically evident EAE. Anti-BLyS treated monkeys were sacrificed with the same clinical signs as saline-treated monkeys, but nevertheless displayed significantly reduced spinal cord demyelination. This effect was not observed in the anti-APRIL treated monkeys. The two antibodies had a different effect on T cell subset activation and the profiles of ex vivo released cytokines. In conclusion, treatment with anti-BLyS and anti-APRIL delays the development of neurological disease in a relevant preclinical model of MS. The two mAbs achieve this effect via different mechanisms

    Biophysical and electrochemical studies of protein-nucleic acid interactions

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    This review is devoted to biophysical and electrochemical methods used for studying protein-nucleic acid (NA) interactions. The importance of NA structure and protein-NA recognition for essential cellular processes, such as replication or transcription, is discussed to provide background for description of a range of biophysical chemistry methods that are applied to study a wide scope of protein-DNA and protein-RNA complexes. These techniques employ different detection principles with specific advantages and limitations and are often combined as mutually complementary approaches to provide a complete description of the interactions. Electrochemical methods have proven to be of great utility in such studies because they provide sensitive measurements and can be combined with other approaches that facilitate the protein-NA interactions. Recent applications of electrochemical methods in studies of protein-NA interactions are discussed in detail

    Tuberculosis Trends in Saudis and Non-Saudis in the Kingdom of Saudi Arabia – A 10 Year Retrospective Study (2000–2009)

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    Tuberculosis (TB) remains a public health problem in the Kingdom of Saudi Arabia (KSA), which has a very large labour force from high TB endemic countries. Understanding the epidemiological and clinical features of the TB problem, and the TB burden in the immigrant workforce, is necessary for improved planning and implementation of TB services and prevention measures
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