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1.
  • Tabiri, S, et al. (författare)
  • 2021
  • swepub:Mat__t
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2.
  • Bravo, L, et al. (författare)
  • 2021
  • swepub:Mat__t
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3.
  • Glasbey, JC, et al. (författare)
  • 2021
  • swepub:Mat__t
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4.
  • Acharya, B. S., et al. (författare)
  • Introducing the CTA concept
  • 2013
  • Ingår i: Astroparticle physics. - : Elsevier BV. - 0927-6505 .- 1873-2852. ; 43, s. 3-18
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project. (C) 2013 Elsevier B.V. All rights reserved.
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5.
  • Khatri, C, et al. (författare)
  • Outcomes after perioperative SARS-CoV-2 infection in patients with proximal femoral fractures: an international cohort study
  • 2021
  • Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 11:11, s. e050830-
  • Tidskriftsartikel (refereegranskat)abstract
    • Studies have demonstrated high rates of mortality in people with proximal femoral fracture and SARS-CoV-2, but there is limited published data on the factors that influence mortality for clinicians to make informed treatment decisions. This study aims to report the 30-day mortality associated with perioperative infection of patients undergoing surgery for proximal femoral fractures and to examine the factors that influence mortality in a multivariate analysis.SettingProspective, international, multicentre, observational cohort study.ParticipantsPatients undergoing any operation for a proximal femoral fracture from 1 February to 30 April 2020 and with perioperative SARS-CoV-2 infection (either 7 days prior or 30-day postoperative).Primary outcome30-day mortality. Multivariate modelling was performed to identify factors associated with 30-day mortality.ResultsThis study reports included 1063 patients from 174 hospitals in 19 countries. Overall 30-day mortality was 29.4% (313/1063). In an adjusted model, 30-day mortality was associated with male gender (OR 2.29, 95% CI 1.68 to 3.13, p<0.001), age >80 years (OR 1.60, 95% CI 1.1 to 2.31, p=0.013), preoperative diagnosis of dementia (OR 1.57, 95% CI 1.15 to 2.16, p=0.005), kidney disease (OR 1.73, 95% CI 1.18 to 2.55, p=0.005) and congestive heart failure (OR 1.62, 95% CI 1.06 to 2.48, p=0.025). Mortality at 30 days was lower in patients with a preoperative diagnosis of SARS-CoV-2 (OR 0.6, 95% CI 0.6 (0.42 to 0.85), p=0.004). There was no difference in mortality in patients with an increase to delay in surgery (p=0.220) or type of anaesthetic given (p=0.787).ConclusionsPatients undergoing surgery for a proximal femoral fracture with a perioperative infection of SARS-CoV-2 have a high rate of mortality. This study would support the need for providing these patients with individualised medical and anaesthetic care, including medical optimisation before theatre. Careful preoperative counselling is needed for those with a proximal femoral fracture and SARS-CoV-2, especially those in the highest risk groups.Trial registration numberNCT04323644
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8.
  • Actis, M., et al. (författare)
  • Design concepts for the Cherenkov Telescope Array CTA : an advanced facility for ground-based high-energy gamma-ray astronomy
  • 2011
  • Ingår i: Experimental astronomy. - : Springer. - 0922-6435 .- 1572-9508. ; 32:3, s. 193-316
  • Tidskriftsartikel (refereegranskat)abstract
    • Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.
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9.
  • Aartsen, M. G., et al. (författare)
  • Very high-energy gamma-ray follow-up program using neutrino triggers from IceCube
  • 2016
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 11
  • Tidskriftsartikel (refereegranskat)abstract
    • We describe and report the status of a neutrino-triggered program in IceCube that generates real-time alerts for gamma-ray follow-up observations by atmospheric-Cherenkov telescopes (MAGIC and VERITAS). While IceCube is capable of monitoring the whole sky continuously, high-energy gamma-ray telescopes have restricted fields of view and in general are unlikely to be observing a potential neutrino-flaring source at the time such neutrinos are recorded. The use of neutrino-triggered alerts thus aims at increasing the availability of simultaneous multi-messenger data during potential neutrino flaring activity, which can increase the discovery potential and constrain the phenomenological interpretation of the high-energy emission of selected source classes (e. g. blazars). The requirements of a fast and stable online analysis of potential neutrino signals and its operation are presented, along with first results of the program operating between 14 March 2012 and 31 December 2015.
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10.
  • Algaba, Juan-Carlos, et al. (författare)
  • Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
  • 2021
  • Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 911:1
  • Forskningsöversikt (refereegranskat)abstract
    • In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.
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11.
  • Abe, H., et al. (författare)
  • Gamma-ray observations of MAXI J1820+070 during the 2018 outburst
  • 2022
  • Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 517:4, s. 4736-4751
  • Tidskriftsartikel (refereegranskat)abstract
    • MAXIJ1820+070 is a low-mass X-ray binary with a black hole (BH) as a compact object. This binary underwent an exceptionally bright X-ray outburst from 2018 March to October, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 h of observations of the MAXI J1820+070 outburst with the H.E.S.S., MAGIC and VERITAS experiments at energies above 200 GeV are presented, together with Fermi-LAT data between 0.1 and 500 GeV, and multiwavelength observations from radio to X-rays. Gamma-ray emission is not detected from MAXI J1820+070, but the obtained upper limits and the multiwavelength data allow us to put meaningful constraints on the source properties under reasonable assumptions regarding the non-thermal particle population and the jet synchrotron spectrum. In particular, it is possible to show that, if a high-energy (HE) gamma-ray emitting region is present during the hard state of the source, its predicted flux should be at most a factor of 20 below the obtained Fermi-LAT upper limits, and closer to them for magnetic fields significantly below equipartition. During the state transitions, under the plausible assumption that electrons are accelerated up to similar to 500 GeV, the multiwavelength data and the gamma-ray upper limits lead consistently to the conclusion that a potential HE and very-HE gamma-ray emitting region should be located at a distance from the BH ranging between 10(11) and 10(13) cm. Similar outbursts from low-mass X-ray binaries might be detectable in the near future with upcoming instruments such as CTA.
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12.
  • Acciari, V. A., et al. (författare)
  • Radio Imaging of the Very-High-Energy gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
  • 2009
  • Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 325:5939, s. 444-448
  • Tidskriftsartikel (refereegranskat)abstract
    • The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.
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13.
  • Bouyoucef, S E, et al. (författare)
  • Poster Session 2 : Monday 4 May 2015, 08
  • 2015
  • Ingår i: European Heart Journal Cardiovascular Imaging. - : Oxford University Press (OUP). - 2047-2404 .- 2047-2412. ; 16 Suppl 1
  • Tidskriftsartikel (refereegranskat)
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14.
  • Abdalla, H., et al. (författare)
  • Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagation
  • 2021
  • Ingår i: Journal of Cosmology and Astroparticle Physics. - : Institute of Physics Publishing (IOPP). - 1475-7516. ; :2
  • Tidskriftsartikel (refereegranskat)abstract
    • The Cherenkov Telescope Array (CTA), the new-generation ground-based observatory for gamma-ray astronomy, provides unique capabilities to address significant open questions in astrophysics, cosmology, and fundamental physics. We study some of the salient areas of gamma-ray cosmology that can be explored as part of the Key Science Projects of CTA, through simulated observations of active galactic nuclei (AGN) and of their relativistic jets. Observations of AGN with CTA will enable a measurement of gamma-ray absorption on the extragalactic background light with a statistical uncertainty below 15% up to a redshift z = 2 and to constrain or detect gamma-ray halos up to intergalactic-magnetic-field strengths of at least 0.3 pG. Extragalactic observations with CTA also show promising potential to probe physics beyond the Standard Model. The best limits on Lorentz invariance violation from gamma-ray astronomy will be improved by a factor of at least two to three. CTA will also probe the parameter space in which axion-like particles could constitute a significant fraction, if not all, of dark matter. We conclude on the synergies between CTA and other upcoming facilities that will foster the growth of gamma-ray cosmology.
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15.
  • Adams, C. B., et al. (författare)
  • Observation of the Gamma-Ray Binary HESS J0632+057 with the HESS, MAGIC, and VERITAS Telescopes
  • 2021
  • Ingår i: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 923:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The results of gamma-ray observations of the binary system HESS J0632 + 057 collected during 450 hr over 15 yr, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these observations were accompanied by measurements of the H alpha emission line. A significant detection of the modulation of the very high-energy gamma-ray fluxes with a period of 316.7 +/- 4.4 days is reported, consistent with the period of 317.3 +/- 0.7 days obtained with a refined analysis of X-ray data. The analysis of data from four orbital cycles with dense observational coverage reveals short-timescale variability, with flux-decay timescales of less than 20 days at very high energies. Flux variations observed over a timescale of several years indicate orbit-to-orbit variability. The analysis confirms the previously reported correlation of X-ray and gamma-ray emission from the system at very high significance, but cannot find any correlation of optical H alpha parameters with fluxes at X-ray or gamma-ray energies in simultaneous observations. The key finding is that the emission of HESS J0632 + 057 in the X-ray and gamma-ray energy bands is highly variable on different timescales. The ratio of gamma-ray to X-ray flux shows the equality or even dominance of the gamma-ray energy range. This wealth of new data is interpreted taking into account the insufficient knowledge of the ephemeris of the system, and discussed in the context of results reported on other gamma-ray binary systems.
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16.
  • Abramowski, A., et al. (författare)
  • The 2010 very high energy gamma-RAY flare and 10 years of multi-wavelength observations of M 87
  • 2012
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 746:2, s. 151-
  • Tidskriftsartikel (refereegranskat)abstract
    • The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3-6) x 10(9) M-circle dot) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE gamma-ray emitter since 2006. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz Very Long Baseline Array, VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times of tau(rise)(d) = (1.69 +/- 0.30) days and tau(decay)(d) = (0.611 +/- 0.080) days, respectively. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (similar to day), peak fluxes (Phi(>0.35 TeV) similar or equal to (1-3) x 10(-11) photons cm(-2) s(-1)), and VHE spectra. VLBA radio observations of 43 GHz of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken similar to 3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core (flux increased by factor similar to 2; variability timescale <2 days). The long-term (2001-2010) multi-wavelength (MWL) light curve of M 87, spanning from radio to VHE and including data from Hubble Space Telescope, Liverpool Telescope, Very Large Array, and European VLBI Network, is used to further investigate the origin of the VHE gamma-ray emission. No unique, common MWL signature of the three VHE flares has been identified. In the outer kiloparsec jet region, in particular in HST-1, no enhanced MWL activity was detected in 2008 and 2010, disfavoring it as the origin of the VHE flares during these years. Shortly after two of the three flares (2008 and 2010), the X-ray core was observed to be at a higher flux level than its characteristic range (determined from more than 60 monitoring observations: 2002-2009). In 2005, the strong flux dominance of HST-1 could have suppressed the detection of such a feature. Published models for VHE gamma-ray emission from M 87 are reviewed in the light of the new data.
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17.
  • Acero, F., et al. (författare)
  • Prospects for Cherenkov Telescope Array Observations of the Young Supernova Remnant RX J1713.7-3946
  • 2017
  • Ingår i: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 840:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We perform simulations for future Cherenkov Telescope Array (CTA) observations of RX J1713.7-3946, a young supernova remnant (SNR) and one of the brightest sources ever discovered in very high energy (VHE) gamma rays. Special attention is paid to exploring possible spatial (anti) correlations of gamma rays with emission at other wavelengths, in particular X-rays and CO/H I emission. We present a series of simulated images of RX J1713.7-3946 for CTA based on a set of observationally motivated models for the gamma-ray emission. In these models, VHE gamma rays produced by high-energy electrons are assumed to trace the nonthermal X-ray emission observed by XMM-Newton, whereas those originating from relativistic protons delineate the local gas distributions. The local atomic and molecular gas distributions are deduced by the NANTEN team from CO and H I observations. Our primary goal is to show how one can distinguish the emission mechanism(s) of the gamma rays (i.e., hadronic versus leptonic, or a mixture of the two) through information provided by their spatial distribution, spectra, and time variation. This work is the first attempt to quantitatively evaluate the capabilities of CTA to achieve various proposed scientific goals by observing this important cosmic particle accelerator.
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18.
  • Veres, P., et al. (författare)
  • Observation of inverse Compton emission from a long gamma-ray burst
  • 2019
  • Ingår i: Nature. - : NATURE PUBLISHING GROUP. - 0028-0836 .- 1476-4687. ; 575:7783, s. 459-
  • Tidskriftsartikel (refereegranskat)abstract
    • Long-duration gamma-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectron volt-to-mega electronvoltband, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission(1,2). Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands(1-6). The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock(7-9). Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C(10,11). Here we report multifrequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 x 10(-6) to 10(12) electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs.
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19.
  • Abdalla, H., et al. (författare)
  • HESS and MAGIC observations of a sudden cessation of a very-high-energy gamma-ray flare in PKS 1510-089 in May 2016
  • 2021
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 648
  • Tidskriftsartikel (refereegranskat)abstract
    • The flat spectrum radio quasar (FSRQ) PKS 1510-089 is known for its complex multiwavelength behaviour and it is one of only a few FSRQs detected in very-high-energy (VHE, E>100 GeV) gamma rays. The VHE gamma -ray observations with H.E.S.S. and MAGIC in late May and early June 2016 resulted in the detection of an unprecedented flare, which revealed, for the first time, VHE gamma -ray intranight variability for this source. While a common variability timescale of 1.5 h has been found, there is a significant deviation near the end of the flare, with a timescale of similar to 20 min marking the cessation of the event. The peak flux is nearly two orders of magnitude above the low-level emission. For the first time, a curvature was detected in the VHE gamma -ray spectrum of PKS 1510-089, which can be fully explained by the absorption on the part of the extragalactic background light. Optical R-band observations with ATOM revealed a counterpart of the gamma -ray flare, even though the detailed flux evolution differs from the VHE gamma -ray light curve. Interestingly, a steep flux decrease was observed at the same time as the cessation of the VHE gamma -ray flare. In the high-energy (HE, E> 100 MeV) gamma -ray band, only a moderate flux increase was observed with Fermi-LAT, while the HE gamma -ray spectrum significantly hardens up to a photon index of 1.6. A search for broad-line region (BLR) absorption features in the gamma -ray spectrum indicates that the emission region is located outside of the BLR. Radio very-long-baseline interferometry observations reveal a fast-moving knot interacting with a standing jet feature around the time of the flare. As the standing feature is located similar to 50 pc from the black hole, the emission region of the flare may have been located at a significant distance from the black hole. If this is indeed a true correlation, the VHE gamma rays must have been produced far down in the jet, where turbulent plasma crosses a standing shock.
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20.
  • Mayer, Manuel, et al. (författare)
  • Constraints on particle acceleration in SS433/W50 from MAGIC and HESS observations
  • 2018
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 612
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. The large jet kinetic power and non-thermal processes occurring in the microquasar SS 433 make this source a good candidate for a very high-energy (VHE) gamma-ray emitter. Gamma-ray fluxes above the sensitivity limits of current Cherenkov telescopes have been predicted for both the central X-ray binary system and the interaction regions of SS 433 jets with the surrounding W50 nebula. Non-thermal emission at lower energies has been previously reported, indicating that efficient particle acceleration is taking place in the system. Aims. We explore the capability of SS 433 to emit VHE gamma rays during periods in which the expected flux attenuation due to periodic eclipses (P-orb similar to 13.1 days) and precession of the circumstellar disk (P-pre similar to 162 days) periodically covering the central binary system is expected to be at its minimum. The eastern and western SS 433/W50 interaction regions are also examined using the whole data set available. We aim to constrain some theoretical models previously developed for this system with our observations. Methods. We made use of dedicated observations from the Major Atmospheric Gamma Imaging Cherenkov telescopes (MAGIC) and High Energy Spectroscopic System (H.E.S.S.) of SS 433 taken from 2006 to 2011. These observation were combined for the first time and accounted for a total effective observation time of 16.5 h, which were scheduled considering the expected phases of minimum absorption of the putative VHE emission. Gamma-ray attenuation does not affect the jet/medium interaction regions. In this case, the analysis of a larger data set amounting to similar to 40-80 h, depending on the region, was employed. Results. No evidence of VHE gamma-ray emission either from the central binary system or from the eastern/western interaction regions was found. Upper limits were computed for the combined data set. Differential fluxes from the central system are found to be less than or similar to 10(-12)-10(-13) TeV-1 cm(-2) s(-1) in an energy interval ranging from similar to few x 100 GeV to similar to few TeV. Integral flux limits down to similar to 10(-12)-10(-13) ph cm(-2) s(-1) and similar to 10(-13)-10(-14) ph cm(-2) s(-1) are obtained at 300 and 800 GeV, respectively. Our results are used to place constraints on the particle acceleration fraction at the inner jet regions and on the physics of the jet/medium interactions. Conclusions. Our findings suggest that the fraction of the jet kinetic power that is transferred to relativistic protons must be relatively small in SS 433, q(p) <= 2.5 x 10(-5), to explain the lack of TeV and neutrino emission from the central system. At the SS 433/W50 interface, the presence of magnetic fields greater than or similar to 10 mu G is derived assuming a synchrotron origin for the observed X-ray emission. This also implies the presence of high-energy electrons with E-e up to 50 TeV, preventing an efficient production of gamma-ray fluxes in these interaction regions.
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21.
  • Korenblik, R., et al. (författare)
  • Dragon 1 Protocol Manuscript : Training, Accreditation, Implementation and Safety Evaluation of Portal and Hepatic Vein Embolization (PVE/HVE) to Accelerate Future Liver Remnant (FLR) Hypertrophy
  • 2022
  • Ingår i: Cardiovascular and Interventional Radiology. - : Springer. - 0174-1551 .- 1432-086X. ; 45, s. 1391-1398
  • Tidskriftsartikel (refereegranskat)abstract
    • Study Purpose The DRAGON 1 trial aims to assess training, implementation, safety and feasibility of combined portal- and hepatic-vein embolization (PVE/HVE) to accelerate future liver remnant (FLR) hypertrophy in patients with borderline resectable colorectal cancer liver metastases. Methods The DRAGON 1 trial is a worldwide multicenter prospective single arm trial. The primary endpoint is a composite of the safety of PVE/HVE, 90-day mortality, and one year accrual monitoring of each participating center. Secondary endpoints include: feasibility of resection, the used PVE and HVE techniques, FLR-hypertrophy, liver function (subset of centers), overall survival, and disease-free survival. All complications after the PVE/HVE procedure are documented. Liver volumes will be measured at week 1 and if applicable at week 3 and 6 after PVE/HVE and follow-up visits will be held at 1, 3, 6, and 12 months after the resection. Results Not applicable. Conclusion DRAGON 1 is a prospective trial to assess the safety and feasibility of PVE/HVE. Participating study centers will be trained, and procedures standardized using Work Instructions (WI) to prepare for the DRAGON 2 randomized controlled trial. Outcomes should reveal the accrual potential of centers, safety profile of combined PVE/HVE and the effect of FLR-hypertrophy induction by PVE/HVE in patients with CRLM and a small FLR.
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22.
  • Ahnen, M. L., et al. (författare)
  • Limits to dark matter annihilation cross-section from a combined analysis of MAGIC and Fermi-LAT observations of dwarf satellite galaxies
  • 2016
  • Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :2
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the first joint analysis of gamma-ray data from the MAGIC Cherenkov telescopes and the Fermi Large Area Telescope (LAT) to search for gamma-ray signals from dark matter annihilation in dwarf satellite galaxies. We combine 158 hours of Segue 1 observations with MAGIC with 6-year observations of 15 dwarf satellite galaxies by the Fermi-LAT. We obtain limits on the annihilation cross-section for dark matter particle masses between 10 GeV and 100 TeV - the widest mass range ever explored by a single gamma-ray analysis. These limits improve on previously published Fermi-LAT and MAGIC results by up to a factor of two at certain masses. Our new inclusive analysis approach is completely generic and can be used to perform a global, sensitivity-optimized dark matter search by combining data from present and future gamma-ray and neutrino detectors.
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23.
  • Aleksic, J., et al. (författare)
  • Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopes
  • 2015
  • Ingår i: Journal of High Energy Astrophysics. - : Elsevier BV. - 2214-4048 .- 2214-4056. ; 5-6, s. 30-38
  • Tidskriftsartikel (refereegranskat)abstract
    • The MAGIC stereoscopic system collected 69 hours of Crab Nebula data between October 2009 and April 2011. Analysis of this data sample using the latest improvements in the MAGIC stereoscopic software provided an unprecedented precision of spectral and night-by-night light curve determination at gamma rays. We derived a differential spectrum with a single instrument from 50 GeV up to almost 30 TeV with 5 bins per energy decade. At low energies, MAGIC results, combined with Fermi-LAT data, show a flat and broad Inverse Compton peak. The overall fit to the data between 1 GeV and 30 TeV is not well described by a log-parabola function. We find that a modified log-parabola function with an exponent of 2.5 instead of 2 provides a good description of the data (chi(2)(red) = 35/26). Using systematic uncertainties of the MAGIC and Fermi-LAT measurements we determine the position of the Inverse Compton peak to be at (53 +/- 3(stat)+ 31(syst)-13(syst)) GeV, which is the most precise estimation up to date and is dominated by the systematic effects. There is no hint of the integral flux variability on daily scales at energies above 300 GeV when systematic uncertainties are included in the flux measurement. We consider three state-of-the-art theoretical models to describe the overall spectral energy distribution of the Crab Nebula. The constant B-field model cannot satisfactorily reproduce the VHE spectral measurements presented in this work, having particular difficulty reproducing the broadness of the observed IC peak. Most probably this implies that the assumption of the homogeneity of the magnetic field inside the nebula is incorrect. On the other hand, the time-dependent 1D spectral model provides a good fit of the new VHE results when considering a 80 mu G magnetic field. However, it fails to match the data when including the morphology of the nebula at lower wavelengths.
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24.
  • Aleksic, J., et al. (författare)
  • MAGIC reveals a complex morphology within the unidentified gamma-ray source HESS J1857+026
  • 2014
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 571
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims. HESS J1857+026 is an extended TeV gamma-ray source that was discovered by H. E. S. S. as part of its Galactic plane survey. Given its broadband spectral energy distribution and its spatial coincidence with the young energetic pulsar PSR J1856+0245, the source has been put forward as a pulsar wind nebula (PWN) candidate. MAGIC has performed follow-up observations aimed at mapping the source down to energies approaching 100 GeV in order to better understand its complex morphology. Methods. HESS J1857+026 was observed by MAGIC in 2010, yielding 29 h of good quality stereoscopic data that allowed us to map the source region in two separate ranges of energy. Results. We detected very-high-energy gamma-ray emission from HESS J1857+026 with a significance of 12 sigma above 150 GeV. The differential energy spectrum between 100 GeV and 13 TeV is described well by a power law function dN/dE = N-0(E/1TeV)(-Gamma) with N-0 = (5.37 +/- 0.44(stat) +/- 1.5(sys)) X 10(-12) (TeV-1 cm(-2) s(-1)) and Gamma = 2.16 +/- 0.07(stat) +/- 0.15(sys), which bridges the gap between the GeV emission measured by Fermi-LAT and the multi-TeV emission measured by H.E.S.S.. In addition, we present a detailed analysis of the energy-dependent morphology of this region. We couple these results with archival multiwavelength data and outline evidence in favor of a two-source scenario, whereby one source is associated with a PWN, while the other could be linked with a molecular cloud complex containing an HII region and a possible gas cavity.
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25.
  • Aleksic, J., et al. (författare)
  • DETECTION OF VERY HIGH ENERGY gamma-RAY EMISSION FROM THE PERSEUS CLUSTER HEAD-TAIL GALAXY IC 310 BY THE MAGIC TELESCOPES
  • 2010
  • Ingår i: The Astrophysical Journal Letters. - 2041-8205. ; 723:2, s. l207-L212
  • Tidskriftsartikel (refereegranskat)abstract
    • We report on the detection with the MAGIC telescopes of very high energy (VHE) gamma-rays from IC 310, a head-tail radio galaxy in the Perseus galaxy cluster, observed during the interval 2008 November to 2010 February. The Fermi satellite has also detected this galaxy. The source is detected by MAGIC at a high statistical significance of 7.6 sigma in 20.6 hr of stereo data. The observed spectral energy distribution is flat with a differential spectral index of -2.00 +/- 0.14. The mean flux above 300 GeV, between 2009 October and 2010 February, (3.1 +/- 0.5) x 10(-12) cm(-2) s(-1), corresponds to (2.5 +/- 0.4)% of Crab Nebula units. Only an upper limit, of 1.9% of Crab Nebula units above 300 GeV, was obtained with the 2008 data. This, together with strong hints (>3 sigma) of flares in the middle of 2009 October and November, implies that the emission is variable. The MAGIC results favor a scenario with the VHE emission originating from the inner jet close to the central engine. More complicated models than a simple one-zone synchrotron self-Compton (SSC) scenario, e. g., multi-zone SSC, external Compton, or hadronic, may be required to explain the very flat spectrum and its extension over more than three orders of magnitude in energy.
  •  
26.
  • Aleksic, J., et al. (författare)
  • Discovery of VHE gamma-rays from the blazar 1ES 1215+303 with the MAGIC telescopes and simultaneous multi-wavelength observations
  • 2012
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 544, s. A142-
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. We present the discovery of very high energy (VHE, E > 100 GeV) gamma-ray emission from the BL Lac object 1ES 1215+303 by the MAGIC telescopes and simultaneous multi-wavelength data in a broad energy range from radio to gamma-rays. Aims. We study the VHE gamma-ray emission from 1ES 1215+303 and its relation to the emissions in other wavelengths. Methods. Triggered by an optical outburst, MAGIC observed the source in 2011 January-February for 20.3 h. The target was monitored in the optical R-band by the KVA telescope that also performed optical polarization measurements. We triggered target of opportunity observations with the Swift satellite and obtained simultaneous and quasi-simultaneous data from the Fermi Large Area Telescope and from the Metsahovi radio telescope. We also present the analysis of older MAGIC data taken in 2010. Results. The MAGIC observations of 1ES 1215+303 carried out in 2011 January-February resulted in the first detection of the source at VHE with a statistical significance of 9.4 sigma. Simultaneously, the source was observed in a high optical and X-ray state. In 2010 the source was observed in a lower state in optical, X-ray, and VHE, while the GeV gamma-ray flux and the radio flux were comparable in 2010 and 2011. The spectral energy distribution obtained with the 2011 data can be modeled with a simple one zone SSC model, but it requires extreme values for the Doppler factor or the electron energy distribution.
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27.
  • Aleksic, J., et al. (författare)
  • PG 1553+113 : FIVE YEARS OF OBSERVATIONS WITH MAGIC
  • 2012
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 748:1, s. 46-
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the results of five years (2005-2009) of MAGIC observations of the BL Lac object PG 1553+113 at very high energies (VHEs; E > 100 GeV). Power-law fits of the individual years are compatible with a steady mean photon index Gamma = 4.27 +/- 0.14. In the last three years of data, the flux level above 150 GeV shows a clear variability (probability of constant flux < 0.001%). The flux variations are modest, lying in the range from 4% to 11% of the Crab Nebula flux. Simultaneous optical data also show only modest variability that seems to be correlated with VHE gamma-ray variability. We also performed a temporal analysis of (all available) simultaneous Fermi/Large Area Telescope data of PG 1553+113 above 1 GeV, which reveals hints of variability in the 2008-2009 sample. Finally, we present a combination of the mean spectrum measured at VHEs with archival data available for other wavelengths. The mean spectral energy distribution can be modeled with a one-zone synchrotron self-Compton model, which gives the main physical parameters governing the VHE emission in the blazar jet.
  •  
28.
  • Blanton, Michael R., et al. (författare)
  • Sloan Digital Sky Survey IV : Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
  • 2017
  • Ingår i: Astronomical Journal. - : IOP Publishing Ltd. - 0004-6256 .- 1538-3881. ; 154:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and. high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z similar to 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z similar to 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs. and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the. Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.
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29.
  • Abolfathi, Bela, et al. (författare)
  • The Fourteenth Data Release of the Sloan Digital Sky Survey : First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment
  • 2018
  • Ingår i: Astrophysical Journal Supplement Series. - : IOP Publishing Ltd. - 0067-0049 .- 1538-4365. ; 235:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014-2016 July) public. Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey; the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data-driven machine-learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from the SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS web site (www.sdss.org) has been updated for this release and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020 and will be followed by SDSS-V.
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30.
  • Acciari, V.A., et al. (författare)
  • Monitoring the magnetar SGR 1935+2154 with the MAGIC telescopes
  • 2022
  • Ingår i: Proceedings of Science. - 1824-8039. ; 395
  • Konferensbidrag (refereegranskat)abstract
    • The Galactic magnetar SGR 1935+2154 was associated with a bright, millisecond-timescale fast radio burst (FRB) which occured in April 2020, during a flaring episode. This was the first time an FRB was unequivocally associated with a Galactic source, and the first FRB for which the nature of the emitting source was identified. Moreover, it was the first FRB with a counterpart at another wavelength correlated in time, an atypical, hard X-ray burst, which provides clear evidence for accompanying non-thermal processes. The MAGIC Telescopes are Imaging Air Cherenkov Telescopes (IACTs) sensitive to very-high-energy (VHE, E>100 GeV) gamma rays. Located at the center of the camera lies the MAGIC Central pixel, a single fully-modified photosensor-toreadout chain to measure millisecond-duration optical signals, displaying a maximum sensitivity at a wavelength of 350 nm. This allows MAGIC to operate simultaneously both as a VHE gammaray and a fast optical telescope. The MAGIC telescopes have monitored SGR 1935+2154 in a multiwavelength campaign involving X-ray, radio and optical facilities. In this contribution, we will show the results on the search for the VHE counterpart of the first SGR-FRB source in this multiwavelength context, as well as the search for fast optical bursts with the MAGIC Central Pixel.
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31.
  • Mola-Caminal, M., et al. (författare)
  • PATJ Low Frequency Variants Are Associated With Worse Ischemic Stroke Functional Outcome A Genome-Wide Meta-Analysis
  • 2019
  • Ingår i: Circulation research. - : Ovid Technologies (Wolters Kluwer Health). - 0009-7330 .- 1524-4571. ; 124:1, s. 114-120
  • Tidskriftsartikel (refereegranskat)abstract
    • Rationale: Ischemic stroke is among the leading causes of adult disability. Part of the variability in functional outcome after stroke has been attributed to genetic factors but no locus has been consistently associated with stroke outcome. Objective: Our aim was to identify genetic loci influencing the recovery process using accurate phenotyping to produce the largest GWAS (genome-wide association study) in ischemic stroke recovery to date. Methods and Results: A 12-cohort, 2-phase (discovery-replication and joint) meta-analysis of GWAS included anterior-territory and previously independent ischemic stroke cases. Functional outcome was recorded using 3-month modified Rankin Scale. Analyses were adjusted for confounders such as discharge National Institutes of Health Stroke Scale. A gene-based burden test was performed. The discovery phase (n=1225) was followed by open (n=2482) and stringent joint-analyses (n=1791). Those cohorts with modified Rankin Scale recorded at time points other than 3-month or incomplete data on previous functional status were excluded in the stringent analyses. Novel variants in PATJ (Pals1-associated tight junction) gene were associated with worse functional outcome at 3-month after stroke. The top variant was rs76221407 (G allele, beta=0.40, P=1.70x10-9). Conclusions: Our results identify a set of common variants in PATJ gene associated with 3-month functional outcome at genome-wide significance level. Future studies should examine the role of PATJ in stroke recovery and consider stringent phenotyping to enrich the information captured to unveil additional stroke outcome loci.
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32.
  • Gordon, C., et al. (författare)
  • EULAR points to consider for conducting clinical trials in systemic lupus erythematosus
  • 2009
  • Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 68:4, s. 470-476
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective: Systemic lupus erythematosus (SLE) is a complex multi-organ disease, characterised by relapses and remissions. Designing a high-quality randomised controlled trial poses many challenges. We have developed evidenced-based recommendations for points to consider in conducting clinical trials in patients with SLE. Methods: The EULAR Task Force on SLE comprised 19 specialists and a clinical epidemiologist. Initially, the evidence for clinical trial end-points in SLE was evaluated and this has been reported separately. A consensus approach was developed by the SLE Task Force in formulating recommendations for points to consider when conducting clinical trials in SLE. Results: The literature review revealed that most outcome measures used in phase 2/3 trials in SLE have not actually been validated in clinical trials, although other forms of validation have been undertaken. The final recommendations for points to consider for conducting clinical trials in SLE address the following areas: study design, eligibility criteria, outcome measures including adverse events, concomitant therapies for SLE and its complications. Conclusions: Recommendations for points to consider when conducting clinical trials in SLE were developed using an evidence-based approach followed by expert consensus. The recommendations should be disseminated, implemented and then reviewed in detail and revised using an evidence-based approach in about 5 years, by which time there will be further evidence to consider from current clinical trials.
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33.
  • Hanly, J G, et al. (författare)
  • Autoantibodies and neuropsychiatric events at the time of systemic lupus erythematosus diagnosis
  • 2008
  • Ingår i: Arthritis and Rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 58:3, s. 843-853
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective. To examine, in an inception cohort of systemic lupus erythematosus (SLE) patients, the association between neuropsychiatric (NP) events and anti-ribosomal P (anti-P), antiphospholipid (lupus anticoagulant [LAC], anticardiolipin), anti-beta 2-glycoprotein I, and anti-NR2 glutamate receptor antibodies. Methods. NP events were identified using the American College of Rheumatology case definitions and clustered into central/peripheral and diffuse/focal events. Attribution of NP events to SLE was determined using decision rules of differing stringency. Autoantibodies were measured without knowledge of NP events or their attribution. Results. Four hundred twelve patients were studied (87.4% female; mean +/- SD age 34.9 +/- 13.5 years, mean +/- SD disease duration 5.0 +/- 4.2 months). There were 214 NP events in 133 patients (32.3%). The proportion of NP events attributed to SLE varied from 15% to 36%. There was no association between autoantibodies and NP events overall. However, the frequency of anti-P antibodies in patients with central NP events attributed to SLE was 4 of 20 (20%), versus 3 of 107 (2.8%) in patients with other NP events and 24 of 279 (8.6%) in those with no NP events (P = 0.04). Among patients with diffuse NP events, 3 of 11 had anti-P antibodies (27%), compared with 4 of 111 patients with other NP events (3.6%) and 24 of 279 of those with no NP events (8.6%) (P 0.02). Specific clinical-serologic associations were found between anti-P and psychosis attributed to SLE (P = 0.02) and between LAC and cerebrovascular disease attributed to SLE (P = 0.038). There was no significant association between other autoantibodies and NP events. Conclusion. Clinically distinct NP events attributed to SLE and occurring around the time of diagnosis were found to be associated with anti-P antibodies and LAC. This Suggests that there are different autoimmune pathogenetic mechanisms, although low sensitivity limits the clinical application of testing for these antibodies.
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34.
  • Hanly, J. G., et al. (författare)
  • Neuropsychiatric events at the time of diagnosis of systemic lupus erythematosus - An international inception cohort study
  • 2007
  • Ingår i: Arthritis and Rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 56:1, s. 265-273
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective. To describe the prevalence, characteristics, attribution, and clinical significance of neuropsychiatric (NP) events in an international inception cohort of systemic lupus erythematosus (SLE) patients. Methods. The study was conducted by the Systemic Lupus International Collaborating Clinics (SLICC). Patients were enrolled within 15 months of fulfilling the American College of Rheumatology (ACR) SLE classification criteria. All NP events within a predefined enrollment window were identified using the ACR case definitions of 19 NP syndromes. Decision rules were derived to determine the proportion of NP disease attributable to SLE. Clinical significance was determined using the Short Form 36 (SF-36) Health Survey and the SLICC/ACR Damage Index (SDI). Results. A total of 572 patients (88% female) were recruited, with a mean +/- SD age of 35 +/- 14 years. The mean +/- SD disease duration was 5.2 +/- 4.2 months. Within the enrollment window, 158 of 572 patients (28%) had at least 1 NP event. In total, there were 242 NP events that encompassed 15 of 19 NP syndromes. The proportion of NP events attributed to SLE varied from 19% to 38% using alternate attribution models and occurred in 6.1-11.7% of patients. Those with NP events, regardless of attribution, had lower scores on the SF-36 and higher SDI scores compared with patients with no NP events. Conclusion. Twenty-eight percent of SLE patients experienced at least 1 NP event around the time of diagnosis of SLE, of which only a minority were attributed to SLE. Regardless of attribution, the occurrence of NP events was associated with reduced quality of life and increased organ damage.
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35.
  • Hanly, J. G., et al. (författare)
  • Short-term outcome of neuropsychiatric events in systemic lupus erythematosus upon enrollment into an international inception cohort study
  • 2008
  • Ingår i: Arthritis and Rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 59:5, s. 721-729
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective. To determine the short-term outcome of neuropsychiatric (NP) events upon enrollment into an international inception cohort of patients with systemic lupus erythematosus (SLE). Methods. The study was performed by the Systemic Lupus International Collaborating Clinics. Patients were enrolled within 15 months of SLE diagnosis and NP events were characterized using the American College of Rheumatology case definitions. Decision rules were derived to identify NP events attributable to SLE. Physician outcome scores of NP events and patient-derived mental component summary (MCS) and physical component summary (PCS) scores of the Short Form 36 were recorded. Results. There were 890 patients (88.7% female) with a mean +/- SD age of 33.8 +/- 13.4 years and mean disease duration of 5.3 +/- 4.2 months. Within the enrollment window, 271 (33.5%) of 890 patients had at least 1 NP event encompassing 15 NP syndromes. NP events attributed to SLE varied from 16.5% to 33.9% using alternate attribution models and occurred in 6.0-11.5% of patients. Outcome scores for NP events attributed to SLE were significantly better than for NP events due to non-SLE causes. Higher global disease activity was associated with worse outcomes. MCS scores were lower in patients with NP events, regardless of attribution, and were also lower in patients with diffuse and central NP events. There was a significant association between physician outcome scores and patient MCS scores only for NP events attributed to SLE. Conclusion. In SLE patients, the short-term outcome of NP events is determined by both the characteristics and attribution of the events. Conclusion. In SLE patients, the short-term outcome of NP events is determined by both the characteristics and attribution of the events.
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36.
  • Bertsias, G., et al. (författare)
  • EULAR recommendations for the management of systemic lupus erythematosus. Report of a task force of the EULAR standing committee for international clinical studies including therapeutics
  • 2008
  • Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 67:2, s. 195-205
  • Forskningsöversikt (refereegranskat)abstract
    • Objective: Systemic lupus erythematosus (SLE) is a complex disease with variable presentations, course and prognosis. We sought to develop evidence-based recommendations addressing the major issues in the management of SLE. Methods: The EULAR Task Force on SLE comprised 19 specialists and a clinical epidemiologist. Key questions for the management of SLE were compiled using the Delphi technique. A systematic search of PubMed and Cochrane Library Reports was performed using McMaster/Hedges clinical queries' strategies for questions related to the diagnosis, prognosis, monitoring and treatment of SLE. For neuropsychiatric, pregnancy and antiphospholipid syndrome questions, the search was conducted using an array of relevant terms. Evidence was categorised based on sample size and type of design, and the categories of available evidence were identified for each recommendation. The strength of recommendation was assessed based on the category of available evidence, and agreement on the statements was measured across the 19 specialists. Results: Twelve questions were generated regarding the prognosis, diagnosis, monitoring and treatment of SLE, including neuropsychiatric SLE, pregnancy, the antiphospholipid syndrome and lupus nephritis. The evidence to support each proposition was evaluated and scored. After discussion and votes, the final recommendations were presented using brief statements. The average agreement among experts was 8.8 out of 10. Conclusion: Recommendations for the management of SLE were developed using an evidence-based approach followed by expert consensus with high level of agreement among the experts.
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37.
  • Bertsias, G. K., et al. (författare)
  • EULAR points to consider for conducting clinical trials in systemic lupus erythematosus: literature based evidence for the selection of endpoints
  • 2009
  • Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 68:4, s. 477-483
  • Forskningsöversikt (refereegranskat)abstract
    • Objective: To assess available evidence on the use of end-points ( outcome measures) in clinical trials in systemic lupus erythematosus (SLE), as a part of the development of evidence-based recommendations for points to consider in clinical trials in SLE. Methods: The European League Against Rheumatism (EULAR) Task Force on SLE comprised 19 specialists, a clinical epidemiologist and a research fellow. Key questions addressing the evidence for clinical trial end-points in SLE were compiled using the Delphi technique. A systematic search of the PubMed and Cochrane Library databases was performed using McMaster/Hedges clinical query strategies and an array of relevant terms. Evidence was categorised based on sample size and type of design, and the categories of available evidence were identified for each recommendation. The strength of recommendation was assessed based on the category of available evidence and agreement on the statements was measured across the 19 specialists. Results: Eight questions were generated regarding end-points for clinical trials. The evidence to support each proposition was evaluated. The literature review revealed that most outcome measures used in phase 2/3 trials in SLE have not been formally validated in clinical trials, although some indirect validation has been undertaken. Conclusion: This systematic literature review forms the evidence base considered in the development of the EULAR recommendations for end-points in clinical trials in SLE.
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38.
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39.
  • Urowitz, M B, et al. (författare)
  • Clinical manifestations and coronary artery disease risk factors at diagnosis of systemic lupus erythematosus: data from an international inception cohort
  • 2007
  • Ingår i: Lupus. - : SAGE Publications. - 0961-2033 .- 1477-0962. ; 16:9, s. 731-735
  • Tidskriftsartikel (refereegranskat)abstract
    • Systemic Lupus International Collaborating Clinics (SLICC) comprises 27 centres from 11 countries. An inception cohort of 918 SLE patients has been assembled according to a standardized protocol between 2000 and 2006. Clinical features, classic coronary artery disease (CAD) risk factors, as well as other potential risk factors were collected. Of the 918 patients 89% were females, and of multi racial origin. Less than half the patients were living in a permanent relationship, 58% had post secondary education and 51% were employed. Eight percent had family history of SLE. At enrolment, with at mean age of diagnosis of 34.5 years, a significant number of patients already had CAD risk factors, such as hypertension (33%) and hypercholesterolemia (36%). Only 15% of the patients were postmenopausal, 16% were current smokers and 3.6% had diabetes at entry to the SLICC-RAS (Registry for Atherosclerosis). A number of patients in this multi-racial, multi-ethnic inception cohort of lupus patients have classic CAD risk factors within a mean of 5.4 months from diagnosis. This cohort will be increased to 1500 patients to be followed yearly for 10 years. This will provide a unique opportunity to evaluate risk factors for accelerated atherosclerosis in SLE.
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40.
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41.
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42.
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43.
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44.
  • Blasco-Herrera, J., et al. (författare)
  • H alpha kinematics of 11 starburst galaxies selected from the Sloan Digital Sky Survey
  • 2013
  • Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 435:3, s. 1958-1983
  • Tidskriftsartikel (refereegranskat)abstract
    • We present analysis of Fabry-Perot interferometric observations for a sample of 11 starburst galaxies with redshift z less than or similar to 0.03 selected from the Sloan Digital Sky Survey. We have targeted the H alpha lambda 6562.78 emission line at spatial sampling of 0.2arcsec-0.4 arcsec and at spectral resolution of R similar to 16 000. Studying two-dimensional maps for the velocity, velocity dispersion, line emission and continuum deliver new insights into the nature of starburst and postburst galaxies. The velocity fields are fitted to an exponential disc model, providing scalelengths and masses, to be compared with the photometric scalelength and the mass estimated from the velocity dispersions. From the line emission, the star formation rates are also calculated and compared with values in the literature. We have found that between 55 and 64 per cent of our sample show large-scale dominating rotation, while 27 per cent show local rotation typically restricted to the central part of each system. The morphology and line profiles in the centre of eight objects are consistent with a recent merger, while another two seem to be involved in a accretion process which, for the moment, has not disrupted their kinematics.
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45.
  • Garcia-Ayllon, M. S., et al. (författare)
  • C-terminal fragments of the amyloid precursor protein in cerebrospinal fluid as potential biomarkers for Alzheimer disease
  • 2017
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
  • Tidskriftsartikel (refereegranskat)abstract
    • This study assesses whether C-terminal fragments (CTF) of the amyloid precursor protein (APP) are present in cerebrospinal fluid (CSF) and their potential as biomarkers for Alzheimer's disease (AD). Immunoprecipitation and simultaneous assay by Western blotting using multiplex fluorescence imaging with specific antibodies against particular domains served to characterize CTFs of APP in human CSF. We demonstrate that APP-CTFs are detectable in human CSF, being the most abundant a 25-kDa fragment, probably resulting from proteolytic processing by eta- secretase. The level of the 25-kDa APP-CTF was evaluated in three independent CSF sample sets of patients and controls. The CSF level of this 25-kDa CTF is higher in subjects with autosomal dominant AD linked to PSEN1 mutations, in demented Down syndrome individuals and in sporadic AD subjects compared to age-matched controls. Our data suggest that APP-CTF could be a potential diagnostic biomarker for AD.
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46.
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47.
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48.
  • Shoenfeld, Y, et al. (författare)
  • Prevalence and clinical correlations of antibodies against six beta 2-glycoprotein-I-related peptides in the antiphospholipid syndrome
  • 2003
  • Ingår i: Journal of Clinical Immunology. - 0271-9142. ; 23:5, s. 377-383
  • Tidskriftsartikel (refereegranskat)abstract
    • Two-hundred ninety five patients with the antiphospholipid syndrome (APS) were studied for the presence of antibodies against six anti-beta2GPI-related peptides Abs. The prevalence of a wide spectrum of clinical and laboratory parameters of APS was evaluated in all patients, and correlated with the presence of each anti-beta2GPI peptide antibody. The rates of the various antipeptides Abs ranged from 18.0 to 63.7%. Altogether, 87.1% of the patients had antibody reactivity against at least one of the six beta2GPI-related peptides. A high degree of simultaneous reactivity against several beta2GPI-peptides was found. Positive and negative correlations were found between several antipeptides Abs and the rates of thrombosis and fetal loss. Our results point to a heterogeneous activity of antiphospholipid Abs in APS patients, directed, often concurrently, against various epitopes of the beta2GPI molecule. Evaluation of APS patients for the presence of specific antipeptides Abs may be of a value in predicting the risk for future thrombotic and obstetrical complication, as well as for specific therapeutic purposes.
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49.
  • Barack, Leor, et al. (författare)
  • Black holes, gravitational waves and fundamental physics : a roadmap
  • 2019
  • Ingår i: Classical and quantum gravity. - : IOP Publishing. - 0264-9381 .- 1361-6382. ; 36:14
  • Forskningsöversikt (refereegranskat)abstract
    • The grand challenges of contemporary fundamental physics dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions. The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields. The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature. The purpose of this work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress. This write-up is an initiative taken within the framework of the European Action on 'Black holes, Gravitational waves and Fundamental Physics'.
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50.
  • Blasco-Herrera, Javier, et al. (författare)
  • An improved method for statistical studies of the internal kinematics of H ii regions : the case of M83
  • 2010
  • Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 407:4, s. 2519-2529
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the integrated H alpha emission line profile for 157 H ii regions in the central 3.4 x 3.4 arcmin2 of the galaxy M83 (NGC 5236). Using the Fabry-Perot interferometer GH alpha FaS, on the 4.2-m William Herschel Telescope on La Palma, we show the importance of a good characterization of the instrumental response function for the study of line profile shapes. The luminosity-velocity dispersion relation is also studied, and in the log(L)-log(Sigma) plane we do not find a linear relation, but an upper envelope with equation log(L-H alpha) = 0.9 log(Sigma) + 38.1. For the adopted distance of 4.5 Mpc, the upper envelope appears at the luminosity L = 1038.5 erg s-1, in full agreement with previous studies of other galaxies, reinforcing the idea of using H ii regions as standard candles.
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