459 research outputs found

    Oscillatory subglacial drainage in the absence of surface melt

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    The presence of strong diurnal cycling in basal water pressure records obtained during the melt season is well established for many glaciers. The behaviour of the drainage system outside the melt season is less well understood. Here we present borehole observations from a surge-type valley glacier in the St Elias Mountains, Yukon Territory, Canada. Our data indicate the onset of strongly correlated multi-day oscillations in water pressure in multiple boreholes straddling a main drainage axis, starting several weeks after the disappearance of a dominant diurnal mode in August 2011 and persisting until at least January 2012, when multiple data loggers suffered power failure. Jökulhlaups provide a template for understanding spontaneous water pressure oscillations not driven by external supply variability. Using a subglacial drainage model, we show that water pressure oscillations can also be driven on a much smaller scale by the interaction between conduit growth and distributed water storage in smaller water pockets, basal crevasses and moulins, and that oscillations can be triggered when water supply drops below a critical value. We suggest this in combination with a steady background supply of water from ground water or englacial drainage as a possible explanation for the observed wintertime pressure oscillations

    Substance Misuse Education for Physicians: Why Older People are Important.

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    This perspective article focuses on the need for training and education for undergraduate medical students on substance-related disorders, and describes initiatives undertaken in the United Kingdom (UK), Netherlands, United States (US), and Norway to develop the skills, knowledge, and attitudes needed by future doctors to treat patients adequately. In addition, we stress that in postgraduate training, further steps should be taken to develop Addiction Medicine as a specialized and transverse medical domain. Alcohol use disorder is a growing public health problem in the geriatric population, and one that is likely to continue to increase as the baby boomer generation ages. Prescription drug misuse is a major concern, and nicotine misuse remains problematic in a substantial minority. Thus, Addiction Medicine training should address the problems for this specific population. In recent years, several countries have started an Addiction Medicine specialty. Although addiction psychiatry has been a subspecialty in the UK and US for more than 20 years, in most countries it has been a more recent development. Additional courses on addiction should be integrated into the curriculum at both undergraduate and postgraduate levels, as well as form part of the continuous training of other medical specialists. It is recommended that further research and mapping of what is currently taught in medical programs be undertaken, so as to enhance medical education in addiction and improve treatment services

    A faster pseudo-primality test

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    We propose a pseudo-primality test using cyclic extensions of Z/nZ\mathbb Z/n \mathbb Z. For every positive integer klognk \leq \log n, this test achieves the security of kk Miller-Rabin tests at the cost of k1/2+o(1)k^{1/2+o(1)} Miller-Rabin tests.Comment: Published in Rendiconti del Circolo Matematico di Palermo Journal, Springe

    Two efficient algorithms for arithmetic of elliptic curves using Frobenius map

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    Healthcare Resource Utilization Among Patients in England with Systemic Sclerosis-Associated Interstitial Lung Disease: A Retrospective Database Analysis

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    Introduction Systemic sclerosis-associated interstitial lung disease (SSc-ILD) places a substantial burden on patients and healthcare systems. The objectives of this study were to describe clinical characteristics and assess healthcare resource utilization and costs of patients with SSc-ILD in England, compared with patients with non-pulmonary organ involvement related to SSc (SSc-OOI). Methods This population-based retrospective study used data from the Clinical Practice Research Datalink linked to Hospital Episode Statistics. Data were extracted from medical records dated January 1, 2005 to March 31, 2016. Patients with SSc were identified and placed in subgroups based on organ involvement: SSc-ILD, SSc-OOI, and both (SSc-ILD-OOI). Patients with SSc-ILD-OOI were included in both the SSc-ILD and SSc-OOI subgroups. All-cause healthcare costs, excluding medication costs, were calculated to 2016 British pounds sterling (£). Results This study included 675 patients with SSc: 174 (26%) had neither ILD nor other organ involvement (OOI); 127 (19%) had SSc-ILD; 477 (71%) had SSc-OOI; 103 (15%) had SSc-ILD-OOI. Age-weighted median [interquartile range (IQR)] annual healthcare costs per patient were: £1496 (£664–£2817) in SSc only; £6375 (£3451–£15,041) in SSc-ILD; £4084 (£1454–£10,105) in SSc-OOI; £6632 (£4023–£17,009) in SSc-ILD-OOI. In multivariate analysis, older age at diagnosis, diagnosis of anemia, and number of comorbid diseases were associated with higher yearly healthcare costs. Conclusion The annual healthcare cost for patients with SSc-ILD is substantial, and higher than that of patients with SSc-OOI or SSc only. These results quantify the economic burden of SSc-ILD in a real-world setting, and highlight the need for treatment of this disease

    Counting points on hyperelliptic curves over finite fields

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    International audienceWe describe some algorithms for computing the cardinality of hyperelliptic curves and their Jacobians over finite fields. They include several methods for obtaining the result modulo small primes and prime powers, in particular an algorithm à la Schoof for genus 2 using Cantor's division polynomials. These are combined with a birthday paradox algorithm to calculate the cardinality. Our methods are practical and we give actual results computed using our current implementation. The Jacobian groups we handle are larger than those previously reported in the literature

    Impact of lung function and baseline clinical characteristics on patient-reported outcome measures in systemic sclerosis-associated interstitial lung disease.

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    OBJECTIVE: The SENSCIS® trial demonstrated a significant reduction of lung function decline in patients with systemic sclerosis (SSc)-associated interstitial lung disease (SSc-ILD) treated with nintedanib, but no significant effect on health-related quality of life (HRQoL). To assess whether SSc/SSc-ILD severity and large changes in lung function correlate with HRQoL, a post-hoc analysis of SENSCIS®, aggregating treatment arms, was undertaken. METHODS: Patient-reported outcome (PRO) measures (St. George's Respiratory Questionnaire [SGRQ], Functional Assessment of Chronic Illness Therapy [FACIT]-Dyspnoea, and Health Assessment Questionnaire-Disability Index [HAQ-DI], incorporating the Scleroderma Health Assessment Questionnaire visual analogue scale [SHAQ VAS]) at baseline and week 52 were assessed for associations to SSc-ILD severity. RESULTS: At baseline and at week 52, forced vital capacity (FVC) 30% fibrosis on high-resolution computed tomography at baseline demonstrated worse PRO measure scores at week 52. After 1 year, patients with a major (>10%) improvement/worsening in FVC demonstrated corresponding improvement/worsening in SGRQ and other PRO measures, significant for the SGRQ symptom domain (p< 0.001). CONCLUSION: Severe SSc-ILD and major deteriorations in lung function have important impacts on HRQoL. Treatments that slow lung function decline and prevent severe SSc-ILD are important to preserve HRQoL. TRIAL REGISTRATION: clinicaltrials.gov, www.clinicaltrials.gov, NCT02597933

    Oscillatory subglacial drainage in the absence of surface melt

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    The presence of strong diurnal cycling in basal water pressure records obtained during the melt season is well established for many glaciers. The behaviour of the drainage system outside the melt season is less well understood. Here we present borehole observations from a surge-type valley glacier in the St Elias Mountains, Yukon Territory, Canada. Our data indicate the onset of strongly correlated multi-day oscillations in water pressure in multiple boreholes straddling a main drainage axis, starting several weeks after the disappearance of a dominant diurnal mode in August 2011 and persisting until at least January 2012, when multiple data loggers suffered power failure. Jökulhlaups provide a template for understanding spontaneous water pressure oscillations not driven by external supply variability. Using a subglacial drainage model, we show that water pressure oscillations can also be driven on a much smaller scale by the interaction between conduit growth and distributed water storage in smaller water pockets, basal crevasses and moulins, and that oscillations can be triggered when water supply drops below a critical value. We suggest this in combination with a steady background supply of water from ground water or englacial drainage as a possible explanation for the observed wintertime pressure oscillations

    Introduction to Configuration Path Integral Monte Carlo

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    In low-temperature high-density plasmas quantum effects of the electrons are becoming increasingly important. This requires the development of new theoretical and computational tools. Quantum Monte Carlo methods are among the most successful approaches to first-principle simulations of many-body quantum systems. In this chapter we present a recently developed method---the configuration path integral Monte Carlo (CPIMC) method for moderately coupled, highly degenerate fermions at finite temperatures. It is based on the second quantization representation of the NN-particle density operator in a basis of (anti-)symmetrized NN-particle states (configurations of occupation numbers) and allows to tread arbitrary pair interactions in a continuous space. We give a detailed description of the method and discuss the application to electrons or, more generally, Coulomb-interacting fermions. As a test case we consider a few quantum particles in a one-dimensional harmonic trap. Depending on the coupling parameter (ratio of the interaction energy to kinetic energy), the method strongly reduces the sign problem as compared to direct path integral Monte Carlo (DPIMC) simulations in the regime of strong degeneracy which is of particular importance for dense matter in laser plasmas or compact stars. In order to provide a self-contained introduction, the chapter includes a short introduction to Metropolis Monte Carlo methods and the second quantization of quantum mechanics.Comment: chapter in book "Introduction to Complex Plasmas: Scientific Challenges and Technological Opportunities", Michael Bonitz, K. Becker, J. Lopez and H. Thomsen (Eds.) Springer Series "Atomic, Optical and Plasma Physics", vol. 82, Springer 2014, pp. 153-194 ISBN: 978-3-319-05436-0 (Print) 978-3-319-05437-7 (Online

    Chromatin accessibility is dynamically regulated across C. elegans development and ageing

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    An essential step for understanding the transcriptional circuits that control development and physiology is the global identification and characterization of regulatory elements. Here we present the first map of regulatory elements across the development and ageing of an animal, identifying 42,245 elements accessible in at least one C. elegans stage. Based on nuclear transcription profiles, we define 15,714 protein-coding promoters and 19,231 putative enhancers, and find that both types of element can drive orientation-independent transcription. Additionally, hundreds of promoters produce transcripts antisense to protein coding genes, suggesting involvement in a widespread regulatory mechanism. We find that the accessibility of most elements is regulated during development and/or ageing and that patterns of accessibility change are linked to specific developmental or physiological processes. The map and characterization of regulatory elements across C. elegans life provides a platform for understanding how transcription controls development and ageing
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