161 research outputs found

    A statistical development of fixed odds betting rules in soccer

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    Two simple but seemingly profitable betting rules for betting on the away win in association football are developed. One rule is consistent with avoiding those games in which there is a clear favourite. The second rule is based directly on modelling bookmaker odds and assessing the residuals under the fitted model. Contrary to previous research the betting rule using the residuals suggests avoiding betting on those games where there are large discrepancies between bookmaker odds and predicted-model odds

    Resolving Fine-Scale Heterogeneity of Co-seismic Slip and the Relation to Fault Structure

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    Fault slip distributions provide important insight into the earthquake process. We analyze high-resolution along-strike co-seismic slip profiles of the 1992 M_w = 7.3 Landers and 1999 M_w = 7.1 Hector Mine earthquakes, finding a spatial correlation between fluctuations of the slip distribution and geometrical fault structure. Using a spectral analysis, we demonstrate that the observed variation of co-seismic slip is neither random nor artificial, but self-affine fractal and rougher for Landers. We show that the wavelength and amplitude of slip variability correlates to the spatial distribution of fault geometrical complexity, explaining why Hector Mine has a smoother slip distribution as it occurred on a geometrically simpler fault system. We propose as a physical explanation that fault complexity induces a heterogeneous stress state that in turn controls co-seismic slip. Our observations detail the fundamental relationship between fault structure and earthquake rupture behavior, allowing for modeling of realistic slip profiles for use in seismic hazard assessment and paleoseismology studies

    Resolving Fine-Scale Heterogeneity of Co-seismic Slip and the Relation to Fault Structure

    Get PDF
    Fault slip distributions provide important insight into the earthquake process. We analyze high-resolution along-strike co-seismic slip profiles of the 1992 M_w = 7.3 Landers and 1999 M_w = 7.1 Hector Mine earthquakes, finding a spatial correlation between fluctuations of the slip distribution and geometrical fault structure. Using a spectral analysis, we demonstrate that the observed variation of co-seismic slip is neither random nor artificial, but self-affine fractal and rougher for Landers. We show that the wavelength and amplitude of slip variability correlates to the spatial distribution of fault geometrical complexity, explaining why Hector Mine has a smoother slip distribution as it occurred on a geometrically simpler fault system. We propose as a physical explanation that fault complexity induces a heterogeneous stress state that in turn controls co-seismic slip. Our observations detail the fundamental relationship between fault structure and earthquake rupture behavior, allowing for modeling of realistic slip profiles for use in seismic hazard assessment and paleoseismology studies

    Early and persistent supershear rupture of the 2018 Mw 7.5 Palu earthquake

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    The speed at which an earthquake rupture propagates affects its energy balance and ground shaking impact. Dynamic models of supershear earthquakes, which are faster than the speed of shear waves, often start at subshear speed and later run faster than Eshelby’s speed. Here we present robust evidence of an early and persistent supershear rupture at the sub-Eshelby speed of the 2018 magnitude 7.5 Palu, Indonesia, earthquake. Slowness-enhanced back-projection of teleseismic data provides a sharp image of the rupture process, along a path consistent with the surface rupture trace inferred by subpixel correlation of synthetic-aperture radar and satellite optical images. The rupture propagated at a sustained velocity of 4.1 km s^(–1) from its initiation to its end, despite large fault bends. The persistent supershear speed is further validated by seismological evidence of far-field Rayleigh Mach waves. The unusual features of this earthquake probe the connections between the rupture dynamics and fault structure. An early supershear transition could be promoted by fault roughness near the hypocentre. Steady rupture propagation at a speed unexpected in homogeneous media could result from the presence of a low-velocity damaged fault zone

    Medical treatment of pediatric urolithiasis

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    In recent years the incidence of pediatric stone disease has increased several fold, mostly due to hypercalciuria and hypocitraturia. The goal of medical treatment is to protect the patient from formation of new stones and expansion of existing ones. The non-pharmacological means to address stone disease include high fluid intake and, frequently, modification of nutritional habits. The pharmacological treatment is based on the chemical composition of the stone and the biochemical abnormalities causing its formation; hence, chemical analysis of the stone, urine and blood is of paramount importance and should be done when the first stone is detected. This review discusses the current options of medical treatment of pediatric urolithiasis

    What parathyroid hormone levels should we aim for in children with stage 5 chronic kidney disease; what is the evidence?

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    The bone disease that occurs as a result of chronic kidney disease (CKD) is not only debilitating but also linked to poor growth and cardiovascular disease. It is suspected that abnormal bone turnover is the main culprit for these poor outcomes. Plasma parathyroid hormone (PTH) levels are used as a surrogate marker of bone turnover, and there is a small number of studies in children that have attempted to identify the range of PTH levels that correlates with normal bone histology. It is clear that high PTH levels are associated with high bone turnover, although the range is wide. However, the ability of PTH levels to distinguish between low and normal bone turnover is less clear. This is an important issue, because current guidelines for calcium and phosphate management are based upon there being an “optimum” range for PTH. This editorial takes a critical look at the evidence upon which these recommendations are based

    Metabolic diagnosis and medical prevention of calcium nephrolithiasis and its systemic manifestations: a consensus statement

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    Background: Recently published guidelines on the medical management of renal stone disease did not address relevant topics in the field of idiopathic calcium nephrolithiasis, which are important also for clinical research. Design: A steering committee identified 27 questions, which were proposed to a faculty of 44 experts in nephrolithiasis and allied fields. A systematic review of the literature was conducted and 5216 potentially relevant articles were selected; from these, 407 articles were deemed to provide useful scientific information. The Faculty, divided into working groups, analysed the relevant literature. Preliminary statements developed by each group were exhaustively discussed in plenary sessions and approved. Results: Statements were developed to inform clinicians on the identification of secondary forms of calcium nephrolithiasis and systemic complications; on the definition of idiopathic calcium nephrolithiasis; on the use of urinary tests of crystallization and of surgical observations during stone treatment in the management of these patients; on the identification of patients warranting preventive measures; on the role of fluid and nutritional measures and of drugs to prevent recurrent episodes of stones; and finally, on the cooperation between the urologist and nephrologist in the renal stone patients. Conclusions: This document has addressed idiopathic calcium nephrolithiasis from the perspective of a disease that can associate with systemic disorders, emphasizing the interplay needed between urologists and nephrologists. It is complementary to the American Urological Association and European Association of Urology guidelines. Future areas for research are identified

    A Review of Drowning Prevention Interventions for Children and Young People in High, Low and Middle Income Countries.

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    Globally, drowning is one of the ten leading causes of child mortality. Children aged <5 years are particularly at risk, and children and young people continue to be overrepresented in drowning statistics. Accordingly, evidence informed interventions to prevent children drowning are of global importance. This review aimed to identify, assess and analyse public health interventions to reduce child drowning and investigate the use of behavioural theories and evaluation frameworks to guide child drowning prevention. Thirteen databases were searched for relevant peer reviewed articles. The systematic review was guided by the PRISMA criteria and registered with PROSPERO. Fifteen articles were included in the final review. Studies were delivered in high, middle and low income countries. Intervention designs varied, one-third of studies targeted children under five. Almost half of the studies relied on education and information to reduce drowning deaths, only three studies used a multi-strategy approach. Minimal use of behavioural theories and/or frameworks was found and just one-third of the studies described formative evaluation. This review reveals an over reliance on education and information as a strategy to prevent drowning, despite evidence for comprehensive multi-strategy approaches. Accordingly, interventions must be supported that use a range of strategies, are shaped by theory and planning and evaluation frameworks, and are robust in intervention design, delivery and evaluation methodology. This approach will provide sound evidence that can be disseminated to inform future practice and policy for drowning prevention
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