71 research outputs found

    Discrepancies between survey and administrative data on the use of mental health services in the general population: findings from a study conducted in Québec

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    <p>Abstract</p> <p>Background</p> <p>Population surveys and health services registers are the main source of data for the management of public health. Yet, the validity of survey data on the use of mental health services has been questioned repeatedly due to the sensitive nature of mental illness and to the risk of recall bias. The main objectives of this study were to compare data on the use of mental health services from a large scale population survey and a national health services register and to identify the factors associated with the discrepancies observed between these two sources of data.</p> <p>Methods</p> <p>This study was based on the individual linkage of data from the cycle 1.2 of the Canadian Community Health Survey (CCHS-1.2) and from the health services register of the Régie de l'assurance maladie du Québec (RAMQ). The RAMQ is the governmental agency managing the Quebec national health insurance program. The analyses mostly focused on the 637 Quebecer respondents who were recorded as users of mental health services in the RAMQ and who were self-reported users or non users of these services in the CCHS-1.2.</p> <p>Results</p> <p>Roughly 75%, of those recorded as users of mental health services users in the RAMQ's register did not report using mental health services in the CCHS-1.2. The odds of disagreement between survey and administrative data were higher in seniors, individuals with a lower level of education, legal or de facto spouses and mothers of young children. They were lower in individuals with a psychiatric disorder and in frequent and more recent users of mental health services according to the RAMQ's register.</p> <p>Conclusions</p> <p>These findings support the hypotheses that social desirability and recall bias are likely to affect the self-reported use of mental health services in a population survey. They stress the need to refine the investigation of mental health services in population surveys and to combine survey and administrative data, whenever possible, to obtain an optimal estimation of the population need for mental health care.</p

    Morphing in nature and beyond: a review of natural and synthetic shape-changing materials and mechanisms

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    Shape-changing materials open an entirely new solution space for a wide range of disciplines: from architecture that responds to the environment and medical devices that unpack inside the body, to passive sensors and novel robotic actuators. While synthetic shape-changing materials are still in their infancy, studies of biological morphing materials have revealed key paradigms and features which underlie efficient natural shape-change. Here, we review some of these insights and how they have been, or may be, translated to artificial solutions. We focus on soft matter due to its prevalence in nature, compatibility with users and potential for novel design. Initially, we review examples of natural shape-changing materials—skeletal muscle, tendons and plant tissues—and compare with synthetic examples with similar methods of operation. Stimuli to motion are outlined in general principle, with examples of their use and potential in manufactured systems. Anisotropy is identified as a crucial element in directing shape-change to fulfil designed tasks, and some manufacturing routes to its achievement are highlighted. We conclude with potential directions for future work, including the simultaneous development of materials and manufacturing techniques and the hierarchical combination of effects at multiple length scales.</p

    alpha-Bromoacetophenone derivatives as neutral protein tyrosine phosphatase inhibitors: Structure-activity relationship

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    A series of α-haloacetophenone derivatives was tested for inhibition of protein tyrosine phosphatases SHP-1 and PTP1B. The results show that the bromides are much more potent than the corresponding chlorides, whereas the phenyl ring is remarkably tolerant to modifications. Derivatization of the phenyl ring with a tripeptide Gly-Glu-Glu resulted in a potent, selective inhibitor against PTP1B. A series of α-haloacetophenone derivatives was tested against SHP-1 and PTB1B to define the SAR

    Aerodynamic performance of the feathered dinosaur Microraptor and the evolution of feathered flight

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    Understanding the aerodynamic performance of feathered, non-avialan dinosaurs is critical to reconstructing the evolution of bird flight. Here we show that the Early Cretaceous five-winged paravian Microraptor is most stable when gliding at high-lift coefficients (low lift/drag ratios). Wind tunnel experiments and flight simulations show that sustaining a high-lift coefficient at the expense of high drag would have been the most efficient strategy for Microraptor when gliding from, and between, low elevations. Analyses also demonstrate that anatomically plausible changes in wing configuration and leg position would have made little difference to aerodynamic performance. Significant to the evolution of flight, we show that Microraptor did not require a sophisticated, ‘modern’ wing morphology to undertake effective glides. This is congruent with the fossil record and also with the hypothesis that symmetric ‘flight’ feathers first evolved in dinosaurs for non-aerodynamic functions, later being adapted to form lifting surface
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