128 research outputs found

    From Correlators to Wilson Loops in Chern-Simons Matter Theories

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    We study n-point correlation functions for chiral primary operators in three dimensional supersymmetric Chern-Simons matter theories. Our analysis is carried on in N=2 superspace and covers N=2,3 supersymmetric CFT's, the N=6 ABJM and the N=8 BLG models. In the limit where the positions of adjacent operators become light-like, we find that the one-loop n-point correlator divided by its tree level expression coincides with a light-like n-polygon Wilson loop. Remarkably, the result can be simply expressed as a linear combination of five dimensional two-mass easy boxes. We manage to evaluate the integrals analytically and find a vanishing result, in agreement with previous findings for Wilson loops.Comment: 32 pages, 6 figures, JHEP

    Comparing the Anglo-American and Israeli-American special relationships in the Obama era: an alliance persistence perspective

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    The Anglo-American and Israeli-American security relationships have proved to be unusually close and have confounded expectations that they would wither away with the changing international environment. In order to explain this, the article proposes a theory of ‘alliance persistence’ that is based on reciprocity over shared geostrategic interests, sentimental attachments and institutionalized security relations. The article employs this theoretical framework to explore how Anglo-American and Israeli-American relations have developed during the Obama administration. It argues that the Anglo-American relationship has been closer because of the two countries’ shared strategic interests, whilst the Israeli-American relationship has experienced divergences in how the security interests of the two sides have been pursued. The article concludes by assessing how the two relationships will fair in the post-Obama era and argues that there are numerous areas of tension in the US-Israeli relationship that risk future tensions. Keywords: Alliance, US-UK, US-Israel, Special Relationship, Obam

    Scattering in ABJ theories

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    We study the correspondence between scattering amplitudes and Wilson loops in three-dimensional Chern-Simons matter theories. In particular, using N=2 superspace formalism, we compute at one loop the whole spectrum of four-point superamplitudes for generic N>=2 supersymmetric theories and find a vanishing result for N=6 ABJ(M) and N=8 BLG models. This restricts the possible range of theories for which Wilson loops/scattering amplitudes duality might work. At two loops, we present the computation of the four-point ABJ scattering amplitude for external chiral superfields. Extending the known result for the ABJM Wilson loop to the ABJ case we find perfect agreement. We also discuss the dual conformal invariance of our results and the relationship between the Feynman diagram computation and unitarity methods. While for the ABJM theory dual conformally invariant integrals exactly reproduce the amplitude, for the ABJ case this happens only up to a residual constant depending on the parity-violating parameter. Finally we propose a BDS-like exponentiation for the amplitude based on an analogy with the four-dimensional N=4 SYM case, and discuss its strong coupling dual counterpart.Comment: 1+54 pages, 8 figure

    The Seventh Data Release of the Sloan Digital Sky Survey

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    This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor correction

    Herbivory, Connectivity, and Ecosystem Resilience: Response of a Coral Reef to a Large-Scale Perturbation

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    Coral reefs world-wide are threatened by escalating local and global impacts, and some impacted reefs have shifted from coral dominance to a state dominated by macroalgae. Therefore, there is a growing need to understand the processes that affect the capacity of these ecosystems to return to coral dominance following disturbances, including those that prevent the establishment of persistent stands of macroalgae. Unlike many reefs in the Caribbean, over the last several decades, reefs around the Indo-Pacific island of Moorea, French Polynesia have consistently returned to coral dominance following major perturbations without shifting to a macroalgae-dominated state. Here, we present evidence of a rapid increase in populations of herbivorous fishes following the most recent perturbation, and show that grazing by these herbivores has prevented the establishment of macroalgae following near complete loss of coral on offshore reefs. Importantly, we found the positive response of herbivorous fishes to increased benthic primary productivity associated with coral loss was driven largely by parrotfishes that initially recruit to stable nursery habitat within the lagoons before moving to offshore reefs later in life. These results underscore the importance of connectivity between the lagoon and offshore reefs for preventing the establishment of macroalgae following disturbances, and indicate that protecting nearshore nursery habitat of herbivorous fishes is critical for maintaining reef resilience

    Oral abstracts 3: RA Treatment and outcomesO13. Validation of jadas in all subtypes of juvenile idiopathic arthritis in a clinical setting

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    Background: Juvenile Arthritis Disease Activity Score (JADAS) is a 4 variable composite disease activity (DA) score for JIA (including active 10, 27 or 71 joint count (AJC), physician global (PGA), parent/child global (PGE) and ESR). The validity of JADAS for all ILAR subtypes in the routine clinical setting is unknown. We investigated the construct validity of JADAS in the clinical setting in all subtypes of JIA through application to a prospective inception cohort of UK children presenting with new onset inflammatory arthritis. Methods: JADAS 10, 27 and 71 were determined for all children in the Childhood Arthritis Prospective Study (CAPS) with complete data available at baseline. Correlation of JADAS 10, 27 and 71 with single DA markers was determined for all subtypes. All correlations were calculated using Spearman's rank statistic. Results: 262/1238 visits had sufficient data for calculation of JADAS (1028 (83%) AJC, 744 (60%) PGA, 843 (68%) PGE and 459 (37%) ESR). Median age at disease onset was 6.0 years (IQR 2.6-10.4) and 64% were female. Correlation between JADAS 10, 27 and 71 approached 1 for all subtypes. Median JADAS 71 was 5.3 (IQR 2.2-10.1) with a significant difference between median JADAS scores between subtypes (p < 0.01). Correlation of JADAS 71 with each single marker of DA was moderate to high in the total cohort (see Table 1). Overall, correlation with AJC, PGA and PGE was moderate to high and correlation with ESR, limited JC, parental pain and CHAQ was low to moderate in the individual subtypes. Correlation coefficients in the extended oligoarticular, rheumatoid factor negative and enthesitis related subtypes were interpreted with caution in view of low numbers. Conclusions: This study adds to the body of evidence supporting the construct validity of JADAS. JADAS correlates with other measures of DA in all ILAR subtypes in the routine clinical setting. Given the high frequency of missing ESR data, it would be useful to assess the validity of JADAS without inclusion of the ESR. Disclosure statement: All authors have declared no conflicts of interest. Table 1Spearman's correlation between JADAS 71 and single markers DA by ILAR subtype ILAR Subtype Systemic onset JIA Persistent oligo JIA Extended oligo JIA Rheumatoid factor neg JIA Rheumatoid factor pos JIA Enthesitis related JIA Psoriatic JIA Undifferentiated JIA Unknown subtype Total cohort Number of children 23 111 12 57 7 9 19 7 17 262 AJC 0.54 0.67 0.53 0.75 0.53 0.34 0.59 0.81 0.37 0.59 PGA 0.63 0.69 0.25 0.73 0.14 0.05 0.50 0.83 0.56 0.64 PGE 0.51 0.68 0.83 0.61 0.41 0.69 0.71 0.9 0.48 0.61 ESR 0.28 0.31 0.35 0.4 0.6 0.85 0.43 0.7 0.5 0.53 Limited 71 JC 0.29 0.51 0.23 0.37 0.14 -0.12 0.4 0.81 0.45 0.41 Parental pain 0.23 0.62 0.03 0.57 0.41 0.69 0.7 0.79 0.42 0.53 Childhood health assessment questionnaire 0.25 0.57 -0.07 0.36 -0.47 0.84 0.37 0.8 0.66 0.4

    Adrenaline to improve survival in out-of-hospital cardiac arrest : the PARAMEDIC2 RCT

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    Background Adrenaline has been used as a treatment for cardiac arrest for many years, despite uncertainty about its effects on long-term outcomes and concerns that it may cause worse neurological outcomes. Objectives The objectives were to evaluate the effects of adrenaline on survival and neurological outcomes, and to assess the cost-effectiveness of adrenaline use. Design This was a pragmatic, randomised, allocation-concealed, placebo-controlled, parallel-group superiority trial and economic evaluation. Costs are expressed in Great British pounds and reported in 2016/17 prices. Setting This trial was set in five NHS ambulance services in England and Wales. Participants Adults treated for an out-of-hospital cardiac arrest were included. Patients were ineligible if they were pregnant, if they were aged < 16 years, if the cardiac arrest had been caused by anaphylaxis or life-threatening asthma, or if adrenaline had already been given. Interventions Participants were randomised to either adrenaline (1 mg) or placebo in a 1 : 1 allocation ratio by the opening of allocation-concealed treatment packs. Main outcome measures The primary outcome was survival to 30 days. The secondary outcomes were survival to hospital admission, survival to hospital discharge, survival at 3, 6 and 12 months, neurological outcomes and health-related quality of life through to 6 months. The economic evaluation assessed the incremental cost per quality-adjusted life-year gained from the perspective of the NHS and Personal Social Services. Participants, clinical teams and those assessing patient outcomes were masked to the treatment allocation. Results From December 2014 to October 2017, 8014 participants were assigned to the adrenaline (n = 4015) or to the placebo (n = 3999) arm. At 30 days, 130 out of 4012 participants (3.2%) in the adrenaline arm and 94 out of 3995 (2.4%) in the placebo arm were alive (adjusted odds ratio for survival 1.47, 95% confidence interval 1.09 to 1.97). For secondary outcomes, survival to hospital admission was higher for those receiving adrenaline than for those receiving placebo (23.6% vs. 8.0%; adjusted odds ratio 3.83, 95% confidence interval 3.30 to 4.43). The rate of favourable neurological outcome at hospital discharge was not significantly different between the arms (2.2% vs. 1.9%; adjusted odds ratio 1.19, 95% confidence interval 0.85 to 1.68). The pattern of improved survival but no significant improvement in neurological outcomes continued through to 6 months. By 12 months, survival in the adrenaline arm was 2.7%, compared with 2.0% in the placebo arm (adjusted odds ratio 1.38, 95% confidence interval 1.00 to 1.92). An adjusted subgroup analysis did not identify significant interactions. The incremental cost-effectiveness ratio for adrenaline was estimated at £1,693,003 per quality-adjusted life-year gained over the first 6 months after the cardiac arrest event and £81,070 per quality-adjusted life-year gained over the lifetime of survivors. Additional economic analyses estimated incremental cost-effectiveness ratios for adrenaline at £982,880 per percentage point increase in overall survival and £377,232 per percentage point increase in neurological outcomes over the first 6 months after the cardiac arrest. Limitations The estimate for survival with a favourable neurological outcome is imprecise because of the small numbers of patients surviving with a good outcome. Conclusions Adrenaline improved long-term survival, but there was no evidence that it significantly improved neurological outcomes. The incremental cost-effectiveness ratio per quality-adjusted life-year exceeds the threshold of £20,000–30,000 per quality-adjusted life-year usually supported by the NHS. Future work Further research is required to better understand patients’ preferences in relation to survival and neurological outcomes after out-of-hospital cardiac arrest and to aid interpretation of the trial findings from a patient and public perspective. Trial registration Current Controlled Trials ISRCTN73485024 and EudraCT 2014-000792-11. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 25. See the NIHR Journals Library website for further project information

    ATHENA detector proposal - a totally hermetic electron nucleus apparatus proposed for IP6 at the Electron-Ion Collider

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    ATHENA has been designed as a general purpose detector capable of delivering the full scientific scope of the Electron-Ion Collider. Careful technology choices provide fine tracking and momentum resolution, high performance electromagnetic and hadronic calorimetry, hadron identification over a wide kinematic range, and near-complete hermeticity.This article describes the detector design and its expected performance in the most relevant physics channels. It includes an evaluation of detector technology choices, the technical challenges to realizing the detector and the R&D required to meet those challenges

    SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems

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    Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. In keeping with SDSS tradition, SDSS-III will provide regular public releases of all its data, beginning with SDSS DR8 (which occurred in Jan 2011). This paper presents an overview of the four SDSS-III surveys. BOSS will measure redshifts of 1.5 million massive galaxies and Lya forest spectra of 150,000 quasars, using the BAO feature of large scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z<0.7 and at z~2.5. SEGUE-2, which is now completed, measured medium-resolution (R=1800) optical spectra of 118,000 stars in a variety of target categories, probing chemical evolution, stellar kinematics and substructure, and the mass profile of the dark matter halo from the solar neighborhood to distances of 100 kpc. APOGEE will obtain high-resolution (R~30,000), high signal-to-noise (S/N>100 per resolution element), H-band (1.51-1.70 micron) spectra of 10^5 evolved, late-type stars, measuring separate abundances for ~15 elements per star and creating the first high-precision spectroscopic survey of all Galactic stellar populations (bulge, bar, disks, halo) with a uniform set of stellar tracers and spectral diagnostics. MARVELS will monitor radial velocities of more than 8000 FGK stars with the sensitivity and cadence (10-40 m/s, ~24 visits per star) needed to detect giant planets with periods up to two years, providing an unprecedented data set for understanding the formation and dynamical evolution of giant planet systems. (Abridged)Comment: Revised to version published in The Astronomical Journa
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