3,553 research outputs found

    Conformal anomaly from gauge fields without gauge fixing

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    We show how the Weyl anomaly generated by gauge fields, can be computed from manifestly gauge invariant and diffeomorphism invariant exact renormalization group equations, without having to fix the gauge at any stage. Regularisation is provided by covariant higher derivatives and by embedding the Maxwell field into a spontaneously broken U(11)U(1|1) supergauge theory. We first provide a realisation that leaves behind two versions of the original U(1)U(1) gauge field, and then construct a manifestly U(11)U(1|1) supergauge invariant flow equation which leaves behind only the original Maxwell field in the spontaneously broken regime.Comment: 24 page

    OH 12.8-0.9: A New Water-Fountain Source

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    We present observational evidence that the OH/IR star OH 12.8-0.9 is the fourth in a class of objects previously dubbed "water-fountain" sources. Using the Very Long Baseline Array, we produced the first images of the water maser emission associated with OH 12.8-0.9. We find that the masers are located in two compact regions with an angular separation of ~109 mas on the sky. The axis of separation between the two maser regions is at a position angle of 1.5 deg. East of North with the blue-shifted (-80.5 to -85.5 km/s) masers located to the North and the red-shifted (-32.0 to -35.5 km/s) masers to the South. In addition, we find that the blue- and red-shifted masers are distributed along arc-like structures ~10-12 mas across oriented roughly perpendicular to the separation axis. The morphology exhibited by the water masers is suggestive of an axisymmetric wind with the masers tracing bow shocks formed as the wind impacts the ambient medium. This bipolar jet-like structure is typical of the three other confirmed water-fountain sources. When combined with the previously observed spectral characteristics of OH 12.8-0.9, the observed spatio-kinematic structure of the water masers provides strong evidence that OH 12.8-0.9 is indeed a member of the water-fountain class.Comment: 12 pages, 2 figures (1 color), accepted for publication in the Ap J Letter

    Likely Impacts of Future Agricultural Change on Upland Farming and Biodiversity

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    Recent decades have witnessed substantial losses of biodiversity in Europe, partly driven by the ecological changes associated with intensification of agricultural production. These changes have particularly affected avian (bird) diversity in marginal areas such as the uplands of the UK. We developed integrated ecological-economic models, using eight different indicators of biodiversity based on avian species richness and individual bird densities. The models represent six different types of farms which are typical for the UK uplands, and were used to assess the outcomes of different agricultural futures. Our results show that the impacts of these future agricultural scenarios on farm incomes, land use and biodiversity are very diverse across policy scenarios and farm types. Moreover, each policy scenario produces un-equal distributions of farm income changes, and gains and losses in alternative biodiversity indicators. This shows that generalisations of the effects of land use change on biodiversity can be misleading. Our results also suggest that a focus on umbrella species or indicators (such as total richness) can miss important compositional effects

    Favorable outcomes with reduced steroid use in juvenile dermatomyositis

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    BACKGROUND: High-intensity glucocorticoid regimens are commonly used to induce and maintain remission in Juvenile Dermatomyositis but are associated with several adverse side-effects. Evidence-based treatment guidelines from North American and European pediatric rheumatology research societies both advocate induction with intravenous pulse steroids followed by high dose oral steroids (2 mg/kg/day), which are then tapered. This study reports the time to disease control with reduced glucocorticoid dosing. METHODS: We retrospectively reviewed the records at a single tertiary-care children\u27s hospital of patients diagnosed with Juvenile Dermatomyositis between 2000 and 2014 who had a minimum of 2 years of follow-up. The primary outcome measure was time to control of muscle and skin disease. Additional outcome measures included glucocorticoid dosing, effect of treatment on height, frequency of calcinosis, and complications from treatment. RESULTS: Of the 69 patients followed during the study period, 31 fulfilled inclusion criteria. Median length of follow-up was 4.58 years, (IQR 3-7.5). Myositis control was achieved in a median of 7.1 months (IQR 0.9-63.4). Cutaneous disease control was achieved in a median of 16.7 months (IQR 4.3-89.5). The median starting dose of glucocorticoids was 0.85 mg/kg/day, (IQR 0.5-1.74). The median duration of steroid treatment was 9.1 months, (IQR 4.7-17.4), while the median duration of any pharmacotherapy was 29.2 months (IQR 10.4 to 121.3). Sustained disease control off medications was achieved in 21/31 (68%) patients by the end of review. Persistent calcinosis was identified in only one patient (3%). CONCLUSION: Current accepted treatment paradigms for Juvenile Dermatomyositis include oral glucocorticoids beginning at 2 mg/kg/day and reduced over a prolonged time period. However, our results suggest that treatment using reduced doses and duration with early use of steroid-sparing agents is comparably effective in achieving favorable outcomes in Juvenile Dermatomyositis

    The melanoma-specific graded prognostic assessment does not adequately discriminate prognosis in a modern population with brain metastases from malignant melanoma

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    The melanoma-specific graded prognostic assessment (msGPA) assigns patients with brain metastases from malignant melanoma to 1 of 4 prognostic groups. It was largely derived using clinical data from patients treated in the era that preceded the development of newer therapies such as BRAF, MEK and immune checkpoint inhibitors. Therefore, its current relevance to patients diagnosed with brain metastases from malignant melanoma is unclear. This study is an external validation of the msGPA in two temporally distinct British populations.Performance of the msGPA was assessed in Cohort I (1997-2008, n=231) and Cohort II (2008-2013, n=162) using Kaplan-Meier methods and Harrell's c-index of concordance. Cox regression was used to explore additional factors that may have prognostic relevance.The msGPA does not perform well as a prognostic score outside of the derivation cohort, with suboptimal statistical calibration and discrimination, particularly in those patients with an intermediate prognosis. Extra-cerebral metastases, leptomeningeal disease, age and potential use of novel targeted agents after brain metastases are diagnosed, should be incorporated into future prognostic models.An improved prognostic score is required to underpin high-quality randomised controlled trials in an area with a wide disparity in clinical care

    Individual Differences in Personality Predict How People Look at Faces

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    Determining the ways in which personality traits interact with contextual determinants to shape social behavior remains an important area of empirical investigation. The specific personality trait of neuroticism has been related to characteristic negative emotionality and associated with heightened attention to negative, emotionally arousing environmental signals. However, the mechanisms by which this personality trait may shape social behavior remain largely unspecified.We employed eye tracking to investigate the relationship between characteristics of visual scanpaths in response to emotional facial expressions and individual differences in personality. We discovered that the amount of time spent looking at the eyes of fearful faces was positively related to neuroticism.This finding is discussed in relation to previous behavioral research relating personality to selective attention for trait-congruent emotional information, neuroimaging studies relating differences in personality to amygdala reactivity to socially relevant stimuli, and genetic studies suggesting linkages between the serotonin transporter gene and neuroticism. We conclude that personality may be related to interpersonal interaction by shaping aspects of social cognition as basic as eye contact. In this way, eye gaze represents a possible behavioral link in a complex relationship between genes, brain function, and personality
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