575 research outputs found

    Dietary isotopes of Madagascar’s extinct megafauna reveal Holocene browsing and grazing guilds

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    Megafauna play a disproportionate role in developing and maintaining their biomes, by regulating plant dispersal, community structure and nutrient cycling. Understanding the ecological roles of extinct megafaunal communities, for example through dietary reconstruction using isotope analysis, is necessary to determine pre-human states and set evidence-based restoration goals. We use δ^{13}C and δ^{15}N isotopic analyses to reconstruct Holocene feeding guilds in Madagascar's extinct megaherbivores, which included elephant birds, hippopotami and giant tortoises that occurred across multiple habitats and elevations. We compare isotopic data from seven taxa and two elephant bird eggshell morphotypes against contemporary regional floral baselines to infer dietary subsistence strategies. Most taxa show high consumption of C_{3} and/or CAM plants, providing evidence of widespread browsing ecology. However, Aepyornis hildebrandti, an elephant bird restricted to the central highlands region, has isotope values with much higher δ^{13}C values than other taxa. This species is interpreted as having obtained up to 48% of its diet from C_{4} grasses. These findings provide new evidence for distinct browsing and grazing guilds in Madagascar's Holocene megaherbivore fauna, with implications for past regional distribution of ecosystems dominated by endemic C_{4} grasses

    Measurement precision and evaluation of the diameter profiles of single wool fibers

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    A recent model of the Single Fiber Analyzer 3001 (SIFAN3001) was firstly employed to obtain the single wool fiber diameter profiles (SfFDPs) at multiple orientations. The results showed that using SIFAN3001 to measure fiber diameter at four orientations for 50 single fibers randomly sub-sampled from each mid-side sample can produce average fiber diameter profiles (AS fFDPs) of fibers within staples. Within the testing regime used, the precision estimates for the total samples were &plusmn;1.3 &micro;m for the mean fiber diameter of staples and 1.4 &micro;m for the average fiber diameter of the AS fFDPs at each scanned step in the diameter profile. The mean diameter ratio (ellipticity) obtained from the four orientations was 1.08&plusmn;0.01, confirming that the Merino wool fibers under review were elliptical rather than circular. The elliptical morphology of wool fibers and the precision of the fiber diameter measurement at each point along a fiber will be considered in the development of a mechanical model of Staple Strength testing.<br /

    Early Holocene human presence in Madagascar evidenced by exploitation of avian megafauna

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    Previous research suggests that people first arrived on Madagascar by ~2500 years before present (years B.P.). This hypothesis is consistent with butchery marks on extinct lemur bones from ~2400 years B.P. and perhaps with archaeological evidence of human presence from ~4000 years B.P. We report >10,500-year-old human-modified bones for the extinct elephant birds Aepyornis and Mullerornis, which show perimortem chop marks, cut marks, and depression fractures consistent with immobilization and dismemberment. Our evidence for anthropogenic perimortem modification of directly dated bones represents the earliest indication of humans in Madagascar, predating all other archaeological and genetic evidence by >6000 years and changing our understanding of the history of human colonization of Madagascar. This revision of Madagascar’s prehistory suggests prolonged human-faunal coexistence with limited biodiversity loss

    Psychological distress among primary school teachers: a comparison with clinical and population samples

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Objectives: This analysis explored the level of psychological distress among primary school teachers in the South West of England as compared to clinical and general population samples. Study design: Secondary analysis of data from the Supporting Teachers And childRen in Schools (STARS) trial completed by up to 90 teachers at baseline, 9, 18 and 30 months of follow up. Methods: We used the Everyday Feelings Questionnaire (EFQ) as a measure of psychological distress. Baseline data on teachers were compared with a population sample of professionals and a clinical sample of patients attending a depression clinic. Results: Our teacher cohort experienced higher levels of psychological distress than comparable professionals from the general population, which were sustained over 30 months follow-up. Levels of psychological distress were lower than those found in the clinical sample. Using a cut-point indicative of moderate depression, our data suggest between 19% and 29% of teachers experienced clinically significant distress at each time-point. Conclusions: We detected high and sustained levels of psychological distress among primary school teachers, which suggests an urgent need for intervention. Effective support for teachers’ mental health is particularly important given the potential impact of poor teacher mental health on pupil wellbeing, pupil attainment and teacher-pupil relationships.The STARS trial was funded by the National Institute for Health Research Public Health Research Programme (project number 10/3006/07) and the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South West Peninsula

    The impact of model grid zooming on tracer transport in the 1999/2000 Arctic polar vortex

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    International audienceWe have used a 3D chemistry transport model to evaluate the transport of HF and CH4 in the stratosphere during the Arctic winter of 1999/2000. Several model experiments were carried out with the use of a zoom algorithm to investigate the effect of different horizontal resolutions. Balloon-borne and satellite-borne observations of HF and CH4 were used to test the model. In addition, air mass descent rates within the polar vortex were calculated and compared to observations. Outside the vortex the model results agree well with the observations, but inside the vortex the model underestimates the observed vertical gradient in HF and CH4, even when the highest available resolution (1°×1°) is applied. The calculated diabatic descent rates agree with observations above potential temperature levels of 450 K. These model results suggest that too strong mixing through the vortex edge could be a plausible cause for the model discrepancies, associated with the calculated mass fluxes, although other reasons are also discussed. Based on our model experiments we conclude that a global 6°×9° resolution is too coarse to represent the polar vortex, whereas the higher resolutions, 3°×2° and 1°×1°, yield similar results, even with a 6°×9° resolution in the tropical region

    Matrix-free calcium in isolated chromaffin vesicles

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    Isolated secretory vesicles from bovine adrenal medulla contain 80 nmol of Ca2+ and 25 nmol of Mg2+ per milligram of protein. As determined with a Ca2+-selective electrode, a further accumulation of about 160 nmol of Ca2+/mg of protein can be attained upon addition of the Ca2+ ionophore A23187. During this process protons are released from the vesicles, in exchange for Ca2+ ions, as indicated by the decrease of the pH in the incubation medium or the release of 9-aminoacridine previously taken up by the vesicles. Intravesicular Mg2+ is not released from the vesicles by A23 187, as determined by atomic emission spectroscopy. In the presence of N H Q , which causes the collapse of the secretory vesicle transmembrane proton gradient (ApH), Ca2+ uptake decreases. Under these conditions A23 187-mediated influx of Ca2+ and efflux of H+ cease at Ca2+ concentrations of about 4 pM. Below this concentration Ca2+ is even released from the vesicles. At the Ca2+ concentration at which no net flux of ions occurs the intravesicular matrix free Ca2+ equals the extravesicular free Ca2+. In the absence of NH4C1 we determined an intravesicular pH of 6.2. Under these conditions the Ca2+ influx ceases around 0.15 pM. From this value and the known pH across the vesicular membrane an intravesicular matrix free Ca2+ concentration of about 24 pM was calculated. This is within the same order of magnitude as the concentration of free Ca2+ in the vesicles determined in the presence of NH4C1. Calculation of the total Ca2+ present in the secretory vesicles gives an apparent intravesicular Ca2+ concentration of 40 mM, which is a factor of lo4 higher than the free intravesicular concentration of Ca2+. It can be concluded, therefore, that the concentration gradient of free Ca2+ across the secretory vesicle membrane in the intact chromaffin cells is probably small, which implies that less energy is required to accumulate and maintain Ca2+ within the vesicles than was previously anticipated

    Molecularly defined diffuse leptomeningeal glioneuronal tumor (DLGNT) comprises two subgroups with distinct clinical and genetic features

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    Diffuse leptomeningeal glioneuronal tumors (DLGNT) represent rare CNS neoplasms which have been included in the 2016 update of the WHO classification. The wide spectrum of histopathological and radiological features can make this enigmatic tumor entity difficult to diagnose. In recent years, large-scale genomic and epigenomic analyses have afforded insight into key genetic alterations occurring in multiple types of brain tumors and provide unbiased, complementary tools to improve diagnostic accuracy. Through genome-wide DNA methylation screening of &gt; 25,000 tumors, we discovered a molecularly distinct class comprising 30 tumors, mostly diagnosed histologically as DLGNTs. Copy-number profiles derived from the methylation arrays revealed unifying characteristics, including loss of chromosomal arm 1p in all cases. Furthermore, this molecular DLGNT class can be subdivided into two subgroups [DLGNT methylation class (MC)-1 and DLGNT methylation class (MC)-2], with all DLGNT-MC-2 additionally displaying a gain of chromosomal arm 1q. Co-deletion of 1p/19q, commonly seen in IDH-mutant oligodendroglioma, was frequently observed in DLGNT, especially in DLGNT-MC-1 cases. Both subgroups also had recurrent genetic alterations leading to an aberrant MAPK/ERK pathway, with KIAA1549:BRAF fusion being the most frequent event. Other alterations included fusions of NTRK1/2/3 and TRIM33:RAF1, adding up to an MAPK/ERK pathway activation identified in 80% of cases. In the DLGNT-MC-1 group, age at diagnosis was significantly lower (median 5 vs 14 years, p &lt; 0.01) and clinical course less aggressive (5-year OS 100, vs 43% in DLGNT-MC-2). Our study proposes an additional molecular layer to the current histopathological classification of DLGNT, of particular use for cases without typical morphological or radiological characteristics, such as diffuse growth and radiologic leptomeningeal dissemination. Recurrent 1p deletion and MAPK/ERK pathway activation represent diagnostic biomarkers and therapeutic targets, respectively—laying the foundation for future clinical trials with, e.g., MEK inhibitors that may improve the clinical outcome of patients with DLGNT

    The effectiveness and cost-effectiveness of the Incredible Years® Teacher Classroom Management programme in primary school children: results of the STARS cluster randomised controlled trial

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    This is the final version of the article. Available from Cambridge University Press via the DOI in this record.Background. We evaluated the effectiveness and cost-effectiveness of the Incredible Years® Teacher Classroom Management (TCM) programme as a universal intervention, given schools’ important influence on child mental health. Methods. A two-arm, pragmatic, parallel group, superiority, cluster randomised controlled trial recruited three cohorts of schools (clusters) between 2012 and 2014, randomising them to TCM (intervention) or Teaching As Usual (TAU-control). TCM was delivered to teachers in six whole-day sessions, spread over 6 months. Schools and teachers were not masked to allocation. The primary outcome was teacher-reported Strengths and Difficulties Questionnaire (SDQ) Total Difficulties score. Random effects linear regression and marginal logistic regression models using Generalised Estimating Equations were used to analyse the outcomes. Trial registration: ISRCTN84130388. Results. Eighty schools (2075 children) were enrolled; 40 (1037 children) to TCM and 40 (1038 children) to TAU. Outcome data were collected at 9, 18, and 30-months for 96, 89, and 85% of children, respectively. The intervention reduced the SDQ-Total Difficulties score at 9 months (mean (S.D.):5.5 (5.4) in TCM v. 6.2 (6.2) in TAU; adjusted mean difference = −1.0; 95% CI−1.9 to −0.1; p = 0.03) but this did not persist at 18 or 30 months. Cost-effectiveness analysis suggested that TCM may be cost-effective compared with TAU at 30-months, but this result was associated with uncertainty so no firm conclusions can be drawn. A priori subgroup analyses suggested TCM is more effective for children with poor mental health. Conclusions. TCM provided a small, short-term improvement to children’s mental health particularly for children who are already struggling.This project was funded by the National Institute for Health Research Public Health Research Programme (project number 10/ 3006/07) and the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South West Peninsula

    Beyond climate change and health: Integrating broader environmental change and natural environments for public health protection and promotion in the UK

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    This is the final version of the article. Available from MDPI via the DOI in this record.Increasingly, the potential short and long-term impacts of climate change on human health and wellbeing are being demonstrated. However, other environmental change factors, particularly relating to the natural environment, need to be taken into account to understand the totality of these interactions and impacts. This paper provides an overview of ongoing research in the Health Protection Research Unit (HPRU) on Environmental Change and Health, particularly around the positive and negative effects of the natural environment on human health and well-being and primarily within a UK context. In addition to exploring the potential increasing risks to human health from water-borne and vector-borne diseases and from exposure to aeroallergens such as pollen, this paper also demonstrates the potential opportunities and co-benefits to human physical and mental health from interacting with the natural environment. The involvement of a Health and Environment Public Engagement (HEPE) group as a public forum of "critical friends" has proven useful for prioritising and exploring some of this research; such public involvement is essential to minimise public health risks and maximise the benefits which are identified from this research into environmental change and human health. Research gaps are identified and recommendations made for future research into the risks, benefits and potential opportunities of climate and other environmental change on human and planetary health.The research was funded in part by the National Institute for Health Research Health Protection Research Unit (NIHR HPRU) in Environmental Change and Health at the London School of Hygiene and Tropical Medicine in partnership with Public Health England (PHE), and in collaboration with the University of Exeter, University College London, and the Met Office (HPRU-2012-10016); the UK Medical Research Council (MRC) and UK Natural Environment Research Council (NERC) for the MEDMI Project (MR/K019341/1, https: //www.data-mashup.org.uk); the Economic and Social Research Council (ESRC) Project (ES/P011489/1); and the NIHR Knowledge Mobilisation Research Fellowship for Maguire

    Training teachers in classroom management to improve mental health in primary school children: the STARS cluster RCT

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    This is the final version. Available from NIHR Journals Library via the DOI in this record.Background Poor mental health in childhood is common, persistent and associated with a range of adverse outcomes that include persistent psychopathology, as well as risk-taking behaviour, criminality and educational failure, all of which may also compromise health. There is a growing policy focus on children’s mental health and the role of schools in particular in addressing this. Objectives To evaluate whether or not the Incredible Years® (IY) Teacher Classroom Management (TCM) training improved children’s mental health, behaviour, educational attainment and enjoyment of school, improved teachers’ mental health and relationship with work, and was cost-effective in relation to potential improvements. Design A two-arm, pragmatic, parallel-group, superiority, cluster randomised controlled trial. Setting A total of 80 UK schools (clusters) were recruited in three distinct cohorts between 2012 and 2014 and randomised to TCM (intervention) or teaching as usual [(TAU) control] with follow-ups at 9, 18 and 30 months. Schools and teachers were not masked to allocation. Participants Eighty schools (n = 2075 children) were randomised: 40 (n = 1037 children) to TCM and 40 (n = 1038 children) to TAU. Interventions TCM was delivered to teachers in six whole-day sessions, spread over 6 months. The explicit goals of TCM are to enhance classroom management skills and improve teacher–student relationships. Main outcome measures The primary planned outcome was the teacher-reported Strengths and Difficulties Questionnaire Total Difficulties (SDQ-TD) score. Random-effects linear regression and marginal logistic regression models using generalized estimating equations were used to analyse outcomes. Results The intervention reduced the SDQ-TD score at 9 months [adjusted mean difference (AMD) –1.0, 95% confidence interval (CI) –1.9 to –0.1; p = 0.03] but there was little evidence of effects at 18 months (AMD –0.1, 95% CI –1.5 to 1.2; p = 0.85) and 30 months (AMD –0.7, 95% CI –1.9 to 0.4; p = 0.23). Planned subgroup analyses suggested that TCM is more effective than TAU for children with poor mental health. Cost-effectiveness analysis using the SDQ-TD suggested that the probability of TCM being cost-effective compared with TAU was associated with some uncertainty (range of 40% to 80% depending on the willingness to pay for a unit improvement in SDQ-TD score). In terms of quality-adjusted life-years (QALYs), there was evidence to suggest that TCM was cost-effective compared with TAU at the National Institute for Health and Care Excellence thresholds of £20,000–30,000 per QALY at 9- and 18-month follow-up, but not at 30-month follow-up. There was evidence of reduced disruptive behaviour (p = 0.04) and reductions in inattention and overactivity (p = 0.02) at the 30-month follow-up. Despite no main effect on educational attainment, subgroup analysis indicated that the intervention’s effect differed between those who did and those who did not have poor mental health for both literacy (interaction p = 0.04) and numeracy (interaction p = 0.03). Independent blind observations and qualitative feedback from teachers suggested that teachers’ behaviour in the classroom changed as a result of attending TCM training. Limitations Teachers were not masked to allocation and attrition was marked for parent-reported data. Conclusions Our findings provide tentative evidence that TCM may be an effective universal child mental health intervention in the short term, particularly for primary school children who are identified as struggling, and it may be a cost-effective intervention in the short term. Future work Further research should explore TCM as a whole-school approach by training all school staff and should evaluate the impact of TCM on academic progress in a more thorough and systematic manner.National Institute for Health Research (NIHR
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