58 research outputs found

    Single left coronary artery with separate origins of proximal and distal right coronary arteries from left anterior descending and circumflex arteries – a previously undescribed coronary circulation

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    A single left coronary artery with right coronary artery arising from either left main stem (LMS) or left anterior descending artery (LAD) or circumflex artery (Cx) is an extremely rare coronary anomaly. This is the first report of separate origins of proximal and distal RCA from LAD and circumflex arteries respectively in a patient with a single left coronary artery. This 57 year old patient presented with unstable angina and severe stenotic disease of LAD and Cx arteries and underwent urgent successful quadruple coronary artery bypass grafting. The anomalies of right coronary artery in terms of their origin, number and distribution are reviewed

    Hyperdominant left anterior descending artery continuing across left ventricular apex as posterior descending artery coexistent with aortic stenosis

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    We describe, in a 61 year old man, with coexistent aortic stenosis, the anomalous origin of posterior descending artery (PDA) from a stenotic left anterior descending (LAD) artery, as its continuation across the left ventricular apex, in the presence of a normally arising and atretic proximal right coronary artery. The patient underwent mechanical aortic valve replacement and triple coronary artery bypass grafting and made an uneventful recovery. To the best of our knowledge, origin of PDA as a continuation of LAD across the left ventricular apex in the presence of a normally arising but atretic proximal right coronary artery has never been described in literature before. There is one previous case report of continuation of LAD as PDA across the left ventricular apex in a patient with single left coronary coronary artery with an absent right coronary ostium. As the blood supply to the entire interventricular septum is derived from this "hyperdominant" LAD system, stenosis of LAD can be catastrophic. A review of literature of the anomalies of right coronary artery and, in particular, of its anomalous origin from LAD and its coexistence with aortic stenosis, is presented

    Item response theory analysis of cognitive tests in people with dementia:a systematic review

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    BACKGROUND: Performance on psychometric tests is key to diagnosis and monitoring treatment of dementia. Results are often reported as a total score, but there is additional information in individual items of tests which vary in their difficulty and discriminatory value. Item difficulty refers to an ability level at which the probability of responding correctly is 50%. Discrimination is an index of how well an item can differentiate between patients of varying levels of severity. Item response theory (IRT) analysis can use this information to examine and refine measures of cognitive functioning. This systematic review aimed to identify all published literature which had applied IRT to instruments assessing global cognitive function in people with dementia. METHODS: A systematic review was carried out across Medline, Embase, PsychInfo and CINHAL articles. Search terms relating to IRT and dementia were combined to find all IRT analyses of global functioning scales of dementia. RESULTS: Of 384 articles identified four studies met inclusion criteria including a total of 2,920 people with dementia from six centers in two countries. These studies used three cognitive tests (MMSE, ADAS-Cog, BIMCT) and three IRT methods (Item Characteristic Curve analysis, Samejima’s graded response model, the 2-Parameter Model). Memory items were most difficult. Naming the date in the MMSE and memory items, specifically word recall, of the ADAS-cog were most discriminatory. CONCLUSIONS: Four published studies were identified which used IRT on global cognitive tests in people with dementia. This technique increased the interpretative power of the cognitive scales, and could be used to provide clinicians with key items from a larger test battery which would have high predictive value. There is need for further studies using IRT in a wider range of tests involving people with dementia of different etiology and severity

    Kiwifruit casual mapping in 2008 : comparisons to 2005 and to other sectors

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    This work was funded by the Foundation for Research, Science and Technology (Contract Number AGRB0301). ARGOS also acknowledges financial assistance from: ZESPRI Innovation Company, Fonterra, Merino New Zealand Inc., COKA (Certified Organic Kiwifruit Growers Association) and in-kind support from Te Runanga O Ngāi Tahu

    Experiences of transdisciplinarity in research on agricultural sustainability

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    The Agricultural Research Group on Sustainability (ARGOS), a transdisciplinary research programme funded by New Zealand’s Public Good Science Fund and business organisations interested in primary production, aims to improve the resilience and sustainability of New Zealand agriculture by comparing organic, integrated and conventionally managed farms and orchards. Researchers from ARGOS write of the programme’s context, research design and major results, but especially they share the highs and lows of their experiences of working in a team made up of researchers from farm management, economics, ecology and social science, in the process of becoming transdisciplinary. These experiences are interpreted through the lens of Bourdieu’s Theory of Practice to demonstrate how researchers respond to working in a field, transdisciplinarity, in which they do not know the ‘rules of the game’ and which, in fact, may not yet have rules. Despite frequently referring to the contestation that occurs in this situation of challenges to identity and making meaning, this is a programme that through continuing negotiation has been adapted to move into its seventh year. As such those who are working or about to work in similar programmes can take heart. If they are having difficulties and disagreements ‐ this is a ‘normal’ experience, to be expected and celebrated as part of a growing and creative process. It does not mean that the transdisciplinary research endeavour should be abandoned but that it requires structural support frameworks at both international and research institute level for a ‘space’ in which it can happen more effectively
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