585 research outputs found

    Extreme multi-decadal trends in the North Atlantic Oscillation

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    Stochastic processes are shown to be useful tools for quantifying extreme trends in climate indices. The variance of the trend distribution is shown to generally increase with autocorrelation, with an increase in extreme trend exceedance probabilities. The winter North Atlantic Oscillation (NAO) index has weak autocorrelation which is underestimated in historical climate models and helps to explain the underestimation of extreme trends. The maximum observed 31-year NAO trend occurred in 1963-1993 and is estimated to have a 1 in 20 chance of being exceeded in the 144-year historical record using fitted stochastic models. Climate models and stochastic models without autocorrelation underestimate this probability as a 1 in 200 chance. The NAO trend in the 1963-1993 window was identified due to its unusual nature. If this window is wrongly treated as a randomly chosen single window, the exceedance probability is further reduced (a 1 in 1000 chance). Post-processing methods are proposed to increase the low autocorrelation in climate models and are shown to improve the simulation of extreme trends and also increase the variance of ensemble mean trends. Future projections show a small systematic increase in end-of-century NAO ensemble mean trends relative to the magnitude of the radiative forcing. The probability of a maximum 31-year trend greater than that observed is 3 7% in the next 75-years (under the higher “business as usual” radiative forcing scenario), which is similar to the historical model probability for the last 75-years. Near-term projections of the next 31 years (2024-2054) are relatively insensitive to the scenario, showing no forced trend in the models but a large ensemble range due to internal variability ( 7.41 to 7.68 hPa/decade) which could increase or decrease regional climate change signals in the Northern Hemisphere by magnitudes that are underestimated when using raw climate model output

    Applying a perceptions and practicalities approach to understanding nonadherence to antiepileptic drugs

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    Summary Objective Nonadherence to antiepileptic drugs (AEDs) is a common cause of poor seizure control. This study examines whether reported adherence to AEDs is related to variables identified in the National Institute for Health and Clinical Excellence (NICE) Medicines Adherence Guidelines as being important to adherence: perceptual factors (AED necessity beliefs and concerns), practical factors (limitations in capability and resources), and perceptions of involvement in treatment decisions. Methods This was a cross-sectional study of people with epilepsy receiving AEDs. Participants completed an online survey hosted by the Epilepsy Society (n = 1,010), or as an audit during inpatient admission (n = 118). Validated questionnaires, adapted for epilepsy, assessed reported adherence to AEDs (Medication Adherence Report Scale [MARS]), perceptions of AEDs (Beliefs about Medicines Questionnaire [BMQ]), and patient perceptions of involvement in treatment decisions (Treatment Empowerment Scale [TES]). Results Low adherence was related to AED beliefs (doubts about necessity: t(577) = 3.90, p < 0.001; and concerns: t(995) = 3.45, p = 0.001), reported limitations in capability and resources (t(589) = 7.78, p < 0.001), and to perceptions of a lack of involvement in treatment decisions (t(623) = 4.48, p < 0.001). In multiple logistic regression analyses, these factors significantly (p < 0.001) increased variance in reported adherence, above that which could be explained by age and clinical variables (seizure frequency, type, epilepsy duration, number of AEDs prescribed). Significance Variables identified in the NICE Medicines Adherence Guidelines as potentially important factors for adherence were found to be related to adherence to AEDs. These factors are potentially modifiable. Interventions to support optimal adherence to AEDs should be tailored to address doubts about AED necessity and concerns about harm, and to overcome practical difficulties, while engaging patients in treatment decisions

    Skilful prediction of Sahel summer rainfall on inter-annual and multi-year timescales

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    This is the final version of the article. Available from Springer Nature via the DOI in this record.Summer rainfall in the Sahel region of Africa exhibits one of the largest signals of climatic variability and with a population reliant on agricultural productivity, the Sahel is particularly vulnerable to major droughts such as occurred in the 1970s and 1980s. Rainfall levels have subsequently recovered, but future projections remain uncertain. Here we show that Sahel rainfall is skilfully predicted on inter-annual and multi-year (that is, >5 years) timescales and use these predictions to better understand the driving mechanisms. Moisture budget analysis indicates that on multi-year timescales, a warmer north Atlantic and Mediterranean enhance Sahel rainfall through increased meridional convergence of low-level, externally sourced moisture. In contrast, year-to-year rainfall levels are largely determined by the recycling rate of local moisture, regulated by planetary circulation patterns associated with the El Niño-Southern Oscillation. Our findings aid improved understanding and forecasting of Sahel drought, paramount for successful adaptation strategies in a changing climate.This work was supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101) and the EU FP7 SPECS project. The contribution of D.P.R. has received funding from the NERC/DFID Future Climate for Africa programme under the AMMA-2050 project, grant number NE/M019977/1

    Global unions: chasing the dream or building the reality?

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    This article takes as its theme the global restructuring of capital and its impact on worker organization. It argues for a reassertion of class in any analysis of global solidarity, and assesses the opportunities and barriers to effective global unionization. Rooted in the UK experience, the article analyzes the impact of the European social dimension on trade unions, before taking the discussion into a global dimension. It concludes by suggesting that there are reasons for cautious optimism in terms of solidarity building, despite difficult historical legacies and the common replacement of action with rhetoric

    Labour market experiences of young UK Bangladeshi men: Identity, inclusion and exclusion in inner-city London

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    Detailed qualitative data are used to explore the processes perpetuatinglabour market disadvantage among young UK-Bangladeshi men living in central London. Strong forces of inclusion within the Bangladeshi community are found to interact with forces of exclusion from ‘mainstream’ society to constrain aspirations and limit opportunities. Though diverse forms of young Bangladeshi masculinity are found, a common pattern is heavy dependency on intra-ethnic networks. Negative experiences of and isolation from ‘mainstream’ society further reinforce reliance on ‘our own people’. However, acute ambivalence towards belonging to a dense Bangladeshi community exists, exemplified in the widespread denigration of the restaurant trade. Many respondents express the desire to ‘break out’ and access new experiences. The findings support current policy emphasis on ‘connecting people to work’ but highlight the more fundamental need to connect people across ethnic boundaries. The paper urges researchers to ‘unpack’ ethnicity to consider carefully what ethnic identity implies in terms of access to resources and opportunities for different individuals in different contexts in order better to understand the diversity of labour market outcomes and the persistence of disadvantage

    Stereotactic ablative body radiotherapy for the treatment of spinal oligometastases

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    Abstract not availableJ.H. Chang, S. Gandhidasan, R. Finnigan, D. Whalley, R. Nair, A. Herschtal, T. Eade, A. Kneebone, J. Ruben, M. Foote, S. Siv

    The consequence of fetal ethanol exposure and adolescent odor re-exposure on the response to ethanol odor in adolescent and adult rats

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    <p>Abstract</p> <p>Background</p> <p>An epidemiologic predictive relationship exists between fetal ethanol exposure and the likelihood for adolescent use. Further, an inverse relationship exists between the age of first experience and the probability of adult abuse. Whether and how the combined effects of prenatal and adolescent ethanol experiences contribute to this progressive pattern remains unknown. Fetal ethanol exposure directly changes the odor attributes of ethanol important for both ethanol odor preference behavior and ethanol flavor perception. These effects persist only to adolescence. Here we tested whether adolescent ethanol odor re-exposure: (Experiment 1) augments the fetal effect on the adolescent behavioral response to ethanol odor; and/or (Experiment 2) perpetuates previously observed adolescent behavioral and neurophysiological responses into adulthood.</p> <p>Methods</p> <p>Pregnant rats received either an ethanol or control liquid diet. Progeny (observers) experienced ethanol odor in adolescence via social interaction with a peer (demonstrators) that received an intragastric infusion of either 1.5 g/kg ethanol or water. Social interactions were scored for the frequency that observers followed their demonstrator. Whole-body plethysmography evaluated the unconditioned behavioral response of observers to ethanol odor in adolescence (P37) or adulthood (P90). The olfactory epithelium of adults was also examined for its neural response to five odorants, including ethanol.</p> <p>Results</p> <p>Experiment 1: Relative to fetal or adolescent exposure alone, adolescent re-exposure enhanced the behavioral response to ethanol odor in P37 animals. Compared to animals with no ethanol experience, rats receiving a single experience (fetal or adolescent) show an enhanced, yet equivalent, ethanol odor response. Fetal ethanol experience also increased olfactory-guided following of an intoxicated peer. Experiment 2: Combined exposure yielded persistence of the behavioral effects only in adult females. We found no evidence for persistence of neurophysiological effects in either sex.</p> <p>Conclusion</p> <p>Fetal ethanol exposure influences adolescent re-exposure, in part, by promoting interactions with intoxicated peers. Re-exposure subsequently enhances ethanol odor responsivity during a key developmental transition point for emergent abuse patterns. While persistence of behavioral effects occurred in females, the level of re-exposure necessary to uniformly yield persistence in both sexes remains unknown. Nonetheless, these results highlight an important relationship between fetal and adolescent experiences that appears essential to the progressive pattern of developing ethanol abuse.</p

    An augmented correlation framework for the estimation of tumour translational and rotational motion during external beam radiotherapy treatments using intermittent monoscopic x-ray imaging and an external respiratory signal

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    © 2018 Institute of Physics and Engineering in Medicine. Increasing evidence shows that intrafraction tumour motion monitoring must include both six degrees of freedom (6DoF): 3D translations and 3D rotations. Existing real-time algorithms for 6DoF target motion estimation require continuous intrafraction fluoroscopic imaging at high frequency, thereby exposing patients to additional high imaging dose. This paper presents the first method capable of 6DoF motion monitoring using intermittent 2D kV imaging and a continuous external respiratory signal. Our approach is to optimise a state-augmented linear correlation model between an external signal and internal 6DoF motion. In standard treatments, the model can be built using information obtained during pre-treatment cone beam CT (CBCT). Real-time 6DoF tumor motion can then be estimated using just the external signal. Intermittent intrafraction kV images are used to update the model parameters, accounting for changes in correlation and baseline shifts. The method was evaluated in silico using data from 6 lung SABR patients, with the internal tumour motion recorded with electromagnetic beacons and the external signal from a bellows belt. Projection images from CBCT (10 Hz) and intermittent kV images were simulated by projecting the 3D Calypso beacon positions onto an imager. IMRT and VMAT treatments were simulated with increasing imaging update intervals: 0.1 s, 1 s, 3 s, 10 s and 30 s. For all the tested clinical scenarios, translational motion estimates with our method had sub-mm accuracy (mean) and precision (standard deviation) while rotational motion estimates were accurate to < and precise to . Motion estimation errors increased as the imaging update interval increased. With the largest imaging update interval (30 s), the errors were mm, mm and mm for translation in the left-right, superior-inferior and anterior-posterior directions, respectively, and , and for rotation around the aforementioned axes for both VMAT and IMRT treatments. In conclusion, we developed and evaluated a novel method for highly accurate real-time 6DoF motion monitoring on a standard linear accelerator without requiring continuous kV imaging. The proposed method achieved sub-mm and sub-degree accuracy on a lung cancer patient dataset
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