4,147 research outputs found

    Mineralogical sources of groundwater fluoride in Archaen bedrock/regolith aquifers: Mass balances from southern India and north-central Sri Lanka

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    STUDY REGION: The Maheshwaram and Waipally catchments of Andhra Pradesh, India, and the Plonnaruwa catchment of north-central Sri Lanka. STUDY FOCUS: The distribution of F across eight crystalline phases and between the bedrock and the regolith at eleven sites in three catchments is documented. Mineral contributions to F release during weathering and regolith development are quantified. NEW HYDROLOGICAL INSIGHTS FOR THE REGION: An estimate of weathering duration for the in situ regolith in Andhra Pradesh, 250-380 Ka, is close to a previous estimate for southern India. Partial or total destruction of the primary F-bearing bedrock minerals and consistent depletion of F in the remnant minerals result in a much reduced total F content in the regolith. Leaching experiments and field relationships, however, indicate a greater potential for F mobilisation to groundwater from the regolith than the bedrock. Schemes for managed aquifer recharge should beware the risk of mobilising additional F to groundwater

    Occupational Stress Management for the UK Construction Professionals: Understanding the Causes and Strategies for Improvement

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    Purpose: The increasing awareness of stress as an issue in the construction industry, and the increased realisation of the more effective approach of preventing stress as opposed to treating mental health has placed a great responsibility on industries that rely heavily on the performance of their workforce. In line with this, this research aims to investigate the causes of stress as well as the best strategies for improving professional resilience and stress management proficiency in the construction industry. Design/Methodology: Using exploratory sequential mixed method research design, the top factors that cause stress, mitigate stress, and to build resilience are identified and discussed. Findings: The findings show thematic similarities in the causes of stress, by displaying a reoccurring theme relating to the quality and lack of information, as well as poor communication among the construction professionals. This implies that poor collaboration and “over-the-wall syndrome” of the construction industry does not only contribute to defective output and reworks, it also has significant impacts on the health and well-being of the professionals. Recommendations are made on how to mitigate stress in the industry, by addressing its root-causes and implementing the identified mitigation strategies. This includes a realistic approach to budgeting and project duration, as well as improved communication and collaboration. Value: Finding of this study could help in mitigating stress and mental health concerns that are currently plaguing the construction industry

    An accurate test for homogeneity of odds ratios based on Cochran's Q-statistic

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    Background: A frequently used statistic for testing homogeneity in a meta-analysis of K independent studies is Cochran's Q. For a standard test of homogeneity the Q statistic is referred to a chi-square distribution with K - 1 degrees of freedom. For the situation in which the effects of the studies are logarithms of odds ratios, the chi-square distribution is much too conservative for moderate size studies, although it may be asymptotically correct as the individual studies become large. Methods: Using a mixture of theoretical results and simulations, we provide formulas to estimate the shape and scale parameters of a gamma distribution to t the distribution of Q. Results: Simulation studies show that the gamma distribution is a good approximation to the distribution for Q. Conclusions: : Use of the gamma distribution instead of the chi-square distribution for Q should eliminate inaccurate inferences in assessing homogeneity in a meta-analysis. (A computer program for implementing this test is provided.) This hypothesis test is competitive with the Breslow-Day test both in accuracy of level and in power

    Multipotential stromal cells in the talus and distal tibia in ankle osteoarthritis – presence, potency and relationships to subchondral bone changes

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    A large proportion of ankle osteoarthritis (OA) has an early onset and is post-traumatic. Surgical interventions have low patient satisfaction and relatively poor clinical outcome, whereas joint-preserving treatments, which rely on endogenous multipotential stromal cells (MSCs), result in suboptimal repair. This study investigates MSC presence and potency in OA-affected talocrural osteochondral tissue. Bone volume fraction (BV/TV) changes for the loading region trabecular volume and subchondral bone plate (SBP) thickness in OA compared with healthy tissue were investigated using microcomputed tomography. CD271-positive MSC topography was related to bone and cartilage damage in OA tissue, and in vitro MSC potency was compared with control healthy iliac crest (IC) MSCs. A 1.3- to 2.5-fold SBP thickening was found in both OA talus and tibia, whereas BV/TV changes were depth-dependent. MSCs were abundant in OA talus and tibia, with similar colony characteristics. Tibial and talar MSCs were tripotential, but talar MSCs had 10-fold lower adipogenesis and twofold higher chondrogenesis than IC MSCs (P = .01 for both). Cartilage damage in both OA tibia and talus correlated with SBP thickening and CD271+ MSCs was 1.4- to twofold more concentrated near the SBP. This work shows multipotential MSCs are present in OA talocrural subchondral bone, with their topography suggesting ongoing involvement in SBP thickening. Potentially, biomechanical stimulation could augment the chondrogenic differentiation of MSCs for joint-preserving treatments

    Valuing Governance

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    Book Summary: As has been abundantly documented in the popular and academic press, the humanities are facing challenging times marked by national debate regarding the importance of the humanities in higher education, program and budget cuts, and an ever-decreasing number of tenure-track jobs. In addition, the humanities face quite literally a quantification of their value as the Academy adopts a more corporate mindset. This volume provides advice to professionals in the humanities on how to forge a useful, compelling, and productive career. The book’s 13 chapters address professional approaches to developing and maintaining an active research agenda, fomenting the ideals of the teacher-scholar model, managing the service demands within and outside the college or university, and navigating institutional politics. The collection offers practical and theoretical approaches to higher education, personal anecdotes, intelligent advice, and interviews with colleagues in the humanities. Specific themes addressed include the transition from graduate student to humanities professional, diverging from prescribed paths, the humanities professor as creative writer, moving from secondary to post-secondary education, humanities in an international, market-based context, and participation in governance structures. [From the publisher] Chapter Summary: This essay focuses on providing insight and practical advice on how committed participation in the governance process offers many positives at any stage of the academic ladder. Drawing upon a practical, theoretical, and anecdotal approach, this article reflects on four areas that are enhanced by participation in governance: 1) visibility; 2) knowledge of the institution and its culture; 3) establishing meaningful friendships campus-wide; and 4) governance as a resource of invaluable advice

    Investigating hyper-vigilance for social threat of lonely children

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    The hypothesis that lonely children show hypervigilance for social threat was examined in a series of three studies that employed different methods including advanced eye-tracking technology. Hypervigilance for social threat was operationalized as hostility to ambiguously motivated social exclusion in a variation of the hostile attribution paradigm (Study 1), scores on the Children’s Rejection-Sensitivity Questionnaire (Study 2), and visual attention to socially rejecting stimuli (Study 3). The participants were 185 children (11 years-7 months to 12 years-6 months), 248 children (9 years-4 months to 11 years-8 months) and 140 children (8 years-10 months to 12 years-10 months) in the three studies, respectively. Regression analyses showed that, with depressive symptoms covaried, there were quadratic relations between loneliness and these different measures of hypervigilance to social threat. As hypothesized, only children in the upper range of loneliness demonstrated elevated hostility to ambiguously motivated social exclusion, higher scores on the rejection sensitivity questionnaire, and disengagement difficulties when viewing socially rejecting stimuli. We found that very lonely children are hypersensitive to social threat

    Bovine colostrum supplementation and upper respiratory symptoms during exercise training: a systematic review and meta-analysis of randomised controlled trials

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    Abstract Background Bovine colostrum is proposed as a nutritional countermeasure to the risk of upper respiratory symptoms (URS) during exercise training. The aim of this systematic review and meta-analysis was to estimate the size of the effect of bovine colostrum supplementation on URS. Methods Databases (CDSR, CENTRAL, Cinahl, ClinicalTrials.gov, Current Controlled Trials, DARE, EMBASE, Medline, PROSPERO and Web of Science) of published, unpublished and ongoing studies were searched for randomised controlled trials of healthy adults (≥18 years), evaluating the effect of oral bovine colostrum supplementation compared to a concurrent control group on URS. Results Five trials (152 participants) met the inclusion criteria, all of which involved individuals involved in regular exercise training. Over an 8–12 week follow-up period, bovine colostrum supplementation when compared to placebo significantly reduced the incidence rate of URS days (rate ratio 0.56, 95 % confidence intervals 0.43 to 0.72, P value < 0.001) and URS episodes (0.62, 0.40 to 0.99, P value = 0.04) by 44 and 38 % respectively. There were limited data and considerable variation in results of included studies for duration of URS episodes hence a meta-analysis of this outcome was deemed inappropriate. The risk of bias assessment in this review was hindered by poor reporting practices of included studies. Due to incomplete reporting of study methods, four of the five studies were judged to have a moderate or high risk of overall bias. Our findings must be interpreted in relation to quantity and quality of the available evidence. Conclusions The present systematic review and meta-analysis provides evidence that bovine colostrum supplementation may be effective in preventing the incidence of URS days and episodes in adults engaged in exercise training. The fact that the majority of included studies did not report significant effects on URS outcomes mitigates concerns about publication bias. The point estimates of the random-effects meta-analyses are greater than the smallest clinically important difference, but the low precision of the individual study estimates means the evidence presented in this review needs to be followed up with an appropriately designed and adequately powered, randomised control trial
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