4,090 research outputs found

    Immediate changes in organic matter and plant available nutrients of Haplic Luvisol soils following different experimental burning intensities in Damak Forest, Hungary

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    One of the major pedological changes produced by wildfires is the drastic modification of forest soil systems properties. To our knowledge, large research gaps are currently present concerning the effect of such fires on forest Haplic Luvisols soils in Central Europe. In this study, the effects of experimental fires on soil organic matter and chemical properties at different burning intensities in a Central European forest were examined. The study was conducted at Damak Forest, in Hungary, ecosystem dominated by deciduous broadleaf trees, including the rare Hungarian oak Quercus frainetto Ten. The experimental fires were carried out in nine different plots on Haplic Luvisol soils transferred from Damak Forest to the burning site. Three types of fuel load were collected from the forest: litter layer, understorey and overstorey. Groups of three plots were burned at low (litter layer), medium intensity (litter and understorey) and high intensity (litter, understorey and overstorey). Pre-fire and post-fire soil samples were taken from each plot, analysed in the laboratory and statistically compared. Key plant nutrients of organic matter, carbon, potassium, calcium, magnesium and phosphorus were analysed from each sample. No significant differences in soil organic matter and carbon between pre- and post-fire samples were observed, but high intensity fires did increase soil pH significantly. Calcium, magnesium and phosphorus availability increased significantly at all fire intensity levels. Soil potassium levels significantly decreased (ca. 50%) for all intensity treatments, in contrast to most literature. Potassium is a key nutrient for ion transport in plants, and any loss of this nutrient from the soil could have significant effects on local agricultural production. Overall, our findings provide evidence that support the maintaining of the current Hungarian fire prevention policy. © 2019 by the authors

    Thoracolumbar spine trauma: review of the evidence.

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    AIM: The aim of this paper was to provide a comprehensive review of literature regarding the classification systems and surgical management of thoracolumbar spine trauma. METHODS: A Pubmed search of thoracolumbar , spine , fracture was used on January 05, 2013. Exclusionary criteria included non-Human studies, case reports, and non-clinical papers. RESULTS. One thousand five hundred twenty manuscripts were initially returned for the combined search string; 150 were carefully reviewed, and 48 manuscripts were included in the review. DISCUSSION: Traumatic spinal cord injury (SCI) has a high prevalence in North America. The thoracolumbar junction is a point of high kinetic energy transfer and often results in thoracolumbar fractures. New classification systems for thoracolumbar spine fractures are being developed in an attempt to standardize evaluation, diagnosis, and treatment as well as reporting in the literature. Earlier classifications such as the Denis 3-column model emphasized anatomic divisions to guide surgical planning. More modern classification systems such as the Thoracolumbar injury classification system (TLICS) emphasize initial neurologic status and structural integrity of the posterior ligamentous complex as a guide for surgical decision making and have demonstrated a high intra- and interobserver reliability. Other systems such as the Load-Sharing Classification aid as a useful tool in planning the extent of instrumentation and fusion. CONCLUSION: There is still much controversy over the surgical management of various thoracolumbar fractures. Level I data exists supporting the nonsurgical management of thoracolumbar burst fractures without neurologic compromise. However, for the majority of fracture types in this region, more randomized controlled trials are necessary to establish standards of care

    Free-for benefit: A stragety to improve the quality of health care and control costs through reimbursement incentives

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    AbstractObjectives. The purpose of this study was to determine whether reimbursement in direct proportion to expected therapeutic benefit is capable of improving the utilization and cost of health care.Background. The benefit associated with a particular medical or surgical treatment varies widely from patient to patient. Nevertheless, payment to the provider of the treatment is essentially invariant under the current fee-for-service system. Under an alternative fee-for-benefit strategy, empiric data are used to construct a multivariable model to predict the exprcted benefit to an individual patient from a particular health care service on the basis of conventional clinical descriptors. The payers and the providers of the service then openly negotiate an explicit economic relation between expected benefit and monetary payment such that payment is directly proportional to benefit.Methods. Computer simulations were performed to determine the potential impact of this fee-for-benefit strategy with respect to medical versus surgical treatment of coronary artery disease.Results. Compared with conventional fee-for-service, fee-for-benefit resulted in a 12% improvement in patient benefit (quality-adjusted survival), a 22% reduction in provider payments and a 55% increase in cost/benefit (the ratio of benefit to payment).Conclusions. The incentives embodied in a fee-for-benefit strategy can be an effective mechanism for encouraging more appropriate health care utilization while simultaneously controlling health care costs

    The dynamics of Abell 2634

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    We have amassed a large sample of velocity data for the cluster of galaxies Abell 2634 which contains the wide-angle tail (WAT) radio source 3C 465. Robust indicators of location and scale and their confidence intervals are used to determine if the cD galaxy, containing the WAT, has a significant peculiar motion. We find a cD peculiar radial velocity of 219 plus or minus 98 km s(exp -1). Further dynamical analyses, including substructure and normality tests, suggest that A 2634 is an unrelaxed cluster whose radio source structure may be bent by the turbulent gas of a recent cluster-subcluster merger

    Using Mendelian randomization to determine causal effects of maternal pregnancy (intrauterine) exposures on offspring outcomes:Sources of bias and methods for assessing them

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    Mendelian randomization (MR), the use of genetic variants as instrumental variables (IVs) to test causal effects, is increasingly used in aetiological epidemiology. Few of the methodological developments in MR have considered the specific situation of using genetic IVs to test the causal effect of exposures in pregnant women on postnatal offspring outcomes. In this paper, we describe specific ways in which the IV assumptions might be violated when MR is used to test such intrauterine effects. We highlight the importance of considering the extent to which there is overlap between genetic variants in offspring that influence their outcome with genetic variants used as IVs in their mothers. Where there is overlap, and particularly if it generates a strong association of maternal genetic IVs with offspring outcome via the offspring genotype, the exclusion restriction assumption of IV analyses will be violated. We recommend a set of analyses that ought to be considered when MR is used to address research questions concerned with intrauterine effects on post-natal offspring outcomes, and provide details of how these can be undertaken and interpreted. These additional analyses include the use of genetic data from offspring and fathers, examining associations using maternal non-transmitted alleles, and using simulated data in sensitivity analyses (for which we provide code). We explore the extent to which new methods that have been developed for exploring violation of the exclusion restriction assumption in the two-sample setting (MR-Egger and median based methods) might be used when exploring intrauterine effects in one-sample MR. We provide a list of recommendations that researchers should use when applying MR to test the effects of intrauterine exposures on postnatal offspring outcomes and use an illustrative example with real data to demonstrate how our recommendations can be applied and subsequent results appropriately interpreted

    Estate planning: important changes in tax law

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    https://egrove.olemiss.edu/dl_dhs/1052/thumbnail.jp

    The Concept of Coordination

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    Interaction-based Mendelian randomization with measured and unmeasured gene-by-covariate interactions

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    Studies leveraging gene-environment (GxE) interactions within Mendelian randomization (MR) analyses have prompted the emergence of two similar methodologies: MR-GxE and MR-GENIUS. Such methods are attractive in allowing for pleiotropic bias to be corrected when using individual instruments. Specifically, MR-GxE requires an interaction to be explicitly identified, while MR-GENIUS does not. We critically examine the assumptions of MR-GxE and MR-GENIUS in the absence of a pre-defined covariate, and propose sensitivity analyses to evaluate their performance. Finally, we explore the effect of body mass index (BMI) upon systolic blood pressure (SBP) using data from the UK Biobank, finding evidence of a positive effect of BMI on SBP. We find both approaches share similar assumptions, though differences between the approaches lend themselves to differing research settings. Where a suitable gene-by-covariate interaction is observed MR-GxE can produce unbiased causal effect estimates. MR-GENIUS can circumvent the need to identify interactions, but as a consequence relies on either the MR-GxE assumptions holding globally, or additional information with respect to the distribution of pleiotropic effects in the absence of an explicitly defined interaction covariate
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