629 research outputs found

    Garside and quadratic normalisation: a survey

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    Starting from the seminal example of the greedy normal norm in braid monoids, we analyse the mechanism of the normal form in a Garside monoid and explain how it extends to the more general framework of Garside families. Extending the viewpoint even more, we then consider general quadratic normalisation procedures and characterise Garside normalisation among them.Comment: 30 page

    Abelian subgroups of Garside groups

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    In this paper, we show that for every abelian subgroup HH of a Garside group, some conjugate g−1Hgg^{-1}Hg consists of ultra summit elements and the centralizer of HH is a finite index subgroup of the normalizer of HH. Combining with the results on translation numbers in Garside groups, we obtain an easy proof of the algebraic flat torus theorem for Garside groups and solve several algorithmic problems concerning abelian subgroups of Garside groups.Comment: This article replaces our earlier preprint "Stable super summit sets in Garside groups", arXiv:math.GT/060258

    Transdisciplinary working to shape systematic reviews and interpret the findings: Commentary

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    This is the final version. Available from BMC via the DOI in this record. Important policy questions tend to span a range of academic disciplines, and the relevant research is often carried out in a variety of social, economic and geographic contexts. In efforts to synthesise research to help inform decisions arising from the policy questions, systematic reviews need conceptual frameworks and ways of thinking that combine knowledge drawn from different academic traditions and contexts; in other words, transdisciplinary research. This paper considers how transdisciplinary working can be achieved with: conceptual frameworks that span traditional academic boundaries; methods for shaping review questions and conceptual frameworks; and methods for interpreting the relevance of findings to different contexts. It also discusses the practical challenges and ultimate benefits of transdisciplinary working for systematic reviews.World Health OrganizationUK Department for International DevelopmentUK aidNational Institute for Health Research (NIHR

    How do "robopets" impact the health and well-being of residents in care homes? A systematic review of qualitative and quantitative evidence

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    This is the final version. Available on open access from Wiley via the DOI in this recordBACKGROUND: Robopets are small animal-like robots which have the appearance and behavioural characteristics of pets. OBJECTIVE: To bring together the evidence of the experiences of staff, residents and family members of interacting with robopets and the effects of robopets on the health and well-being of older people living in care homes. DESIGN: Systematic review of qualitative and quantitative research. DATA SOURCES: We searched 13 electronic databases from inception to July 2018 and undertook forward and backward citation chasing. METHODS: Eligible studies reported the views and experiences of robopets from residents, family members and staff (qualitative studies using recognised methods of qualitative data collection and analysis) and the effects of robopets on the health and well-being of care home residents (randomised controlled trials, randomised crossover trials and cluster randomised trials). Study selection was undertaken independently by two reviewers. We used the Wallace criteria and the Cochrane Risk of Bias tool to assess the quality of the evidence. We developed a logic model with stakeholders and used this as a framework to guide data extraction and synthesis. Where appropriate, we used meta-analysis to combine effect estimates from quantitative studies. RESULTS: Nineteen studies (10 qualitative, 2 mixed methods and 7 randomised trials) met the inclusion criteria. Interactions with robopets were described as having a positive impact on aspects of well-being including loneliness, depression and quality of life by residents and staff, although there was no corresponding statistically significant evidence from meta-analysis for these outcomes. Meta-analysis showed evidence of a reduction in agitation with the robopet "Paro" compared to control (-0.32 [95% CI -0.61 to -0.04, p = 0.03]). Not everyone had a positive experience of robopets. CONCLUSIONS: Engagement with robopets appears to have beneficial effects on the health and well-being of older adults living in care homes, but not all chose to engage. Whether the benefits can be sustained are yet to be investigated. IMPLICATIONS FOR PRACTICE: Robopets have the potential to benefit people living in care homes, through increasing engagement and interaction. With the robopet acting as a catalyst, this engagement and interaction may afford comfort and help reduce agitation and loneliness.National Institute for Health Research (NIHR

    Cross-hemispheric Alternating Current Stimulation During a Nap Disrupts Slow Wave Activity and Associated Memory Consolidation.

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    Slow Wave Activity (SWA), the low frequency (<4 Hz) oscillations that characterize Slow Wave Sleep (SWS) are thought to relate causally to declarative memory consolidation during nocturnal sleep. Evidence is conflicting relating SWA to memory consolidation during nap however

    The aorta can act as a site of naïve CD4+ T-cell priming

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    Aims: Aortic adaptive immunity plays a role in atherosclerosis; however, the precise mechanisms leading to T-cell activation in the arterial wall remain poorly understood. Methods and results: Here, we have identified naïve T cells in the aorta of wild-Type and T-cell receptor transgenic mice and we demonstrate that naïve T cells can be primed directly in the vessel wall with both kinetics and frequency of T-cell activation found to be similar to splenic and lymphoid T cells. Aortic homing of naïve T cells is regulated at least in part by the P-selectin glycosylated ligand-1 receptor. In experimental atherosclerosis the aorta supports CD4+ T-cell activation selectively driving Th1 polarization. By contrast, secondary lymphoid organs display Treg expansion. Conclusion: Our results demonstrate that the aorta can support T-cell priming and that naïve T cells traffic between the circulation and vessel wall. These data underpin the paradigm that local priming of T cells specific for plaque antigens contributes to atherosclerosis progression

    Tolerance induction in memory CD4 T cells requires two rounds of antigen-specific activation

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    Autoimmune diseases are driven by immune cells that recognize self-tissues. A major goal for treatment strategies for autoimmune diseases is to turn off or tolerize self-reactive immune cells such as CD4 T cells that coordinate tissue damage in many autoimmune diseases. Autoimmune diseases are often diagnosed many years following their onset. The self-reactive CD4 T cells that must be tolerized, therefore, are previously activated or memory CD4 T cells. Little is known about whether tolerance can be induced in memory CD4 T cells. This paper demonstrates that memory CD4 T cells survive initial exposure to tolerance-inducing signals but that a second activation signal leads to cell death. This study has important implications for immunotherapeutic strategies for autoimmune diseases

    Human health impacts of exposure to phthalate plasticizers: An overview of reviews

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    This is the final version. Available on open access from Elsevier via the DOI in this recordIn this review of reviews, we overview the current global body of available evidence from structured reviews of epidemiological studies that explore human health outcomes associated with exposure to phthalates (chemical plasticisers commonly found in plastics). We found robust evidence for an association with lower semen quality, neurodevelopment and risk of childhood asthma, and moderate to robust evidence for impact on anogenital distance in boys. We identified moderate evidence for an association between phthalates/metabolites and low birthweight, endometriosis, decreased testosterone, ADHD, Type 2 diabetes and breast/uterine cancer. There was some evidence for other outcomes including anofourchette distance, fetal sex hormones, pre-term birth, lower antral follicle count, reduced oestrodiol, autism, obesity, thyroid function and hearing disorders. We found no reviews of epidemiological human studies on the impact of phthalates from recycled plastics on human health. We recommend that future research should use urine samples as exposure measures, consider confounders in analyses and measure impacts on female reproductive systems. Our findings align with emerging research indicating that health risks can occur at exposure levels below the "safe dose" levels set out by regulators, and are of particular concern given potential additive or synergistic "cocktail effects" of chemicals. This raises important policy and regulatory issues for identifying and controlling plastics and health related impacts and highlights a need for more research into substances of concern entering plastics waste streams via recycling.Engineering and Physical Sciences Research Council (EPSRC
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