3,013 research outputs found
New VR magnification ratios of QSO 0957+561
We present VR magnification ratios of QSO 0957+561, which are inferred from
the GLITP light curves of Q0957+561A and new frames taken with the 2.56m Nordic
Optical Telescope about 14 months after the GLITP monitoring. From two
photometric approaches and a reasonable range for the time delay in the system
(415-430 days), we do not obtain achromatic optical continuum ratios, but
ratios depending on the wavelength. These new measurements are consistent with
differential extinction in the lens galaxy, the Lyman limit system, the damped
Ly-alpha system, or the host galaxy of the QSO. The possible values for the
differential extinction and the ratio of total to selective extinction in the V
band are reasonable. Moreover, crude probability arguments suggest that the ray
paths of the two components cross a similar dusty environment, including a
network of compact dust clouds and compact dust voids. As an alternative (in
fact, the usual interpretation of the old ratios), we also try to explain the
new ratios as caused by gravitational microlensing in the deflector. From
magnification maps for each of the gravitationally lensed images, using
different fractions of the surface mass density represented by the microlenses,
as well as different sizes and profiles of the V-band and R-band sources,
several synthetic distributions of V-band and R-band ratios are derived. In
some gravitational scenarios, there is an apparent disagreement between the
observed pair of ratios and the simulated distributions. However, several
microlensing pictures work well. To decide between either extinction, or
microlensing, or a mixed scenario (extinction + microlensing), new
observational and interpretation efforts are required.Comment: PS and PDF versions are created from the LaTeX file and 5 EPS
figures, two additional figues (Figs. 6 and 7) in JPEG format, scheduled for
the ApJ 20 January 2005 issu
QSO 2237+0305 VR light curves from Gravitational Lenses International Time Project optical monitoring
We present VR observations of QSO 2237+0305 conducted by the GLITP
collaboration from 1999 October 1 to 2000 February 3. The observations were
made with the 2.56 m Nordic Optical Telescope at Roque de los Muchachos
Observatory, La Palma (Spain). The PSF fitting method and an adapted version of
the ISIS subtraction method have been used to derive the VR light curves of the
four components (A-D) of the quasar. The mean errors range in the intervals
0.01-0.04 mag (PSF fitting) and 0.01-0.02 mag (ISIS subtraction), with the
faintest component (D) having the largest uncertainties. We address the
relatively good agreement between the A-D light curves derived using different
filters, photometric techniques, and telescopes. The new VR light curves of
component A extend the time coverage of a high magnification microlensing peak,
which was discovered by the OGLE team.Comment: 15 pages, 3 figures, ApJ accepted (Feb 19
The nature and size of the optical continuum source in QSO 2237+0305
From the peak of a gravitational microlensing high-magnification event in the
A component of QSO 2237+0305, which was accurately monitored by the GLITP
collaboration, we derived new information on the nature and size of the optical
V-band and R-band sources in the far quasar. If the microlensing peak is caused
by a microcaustic crossing, we firstly obtained that the standard accretion
disk is a scenario more reliable/feasible than other usual axially symmetric
models. Moreover, the standard scenario fits both the V-band and R-band
observations with reduced chi-square values very close to one. Taking into
account all these results, a standard accretion disk around a supermassive
black hole is a good candidate to be the optical continuum main source in QSO
2237+0305. Secondly, using the standard source model and a robust upper limit
on the transverse galactic velocity, we inferred that 90 per cent of the V-band
and R-band luminosities are emitted from a region with radial size less than
1.2 10^{-2} pc (= 3.7 10^{16} cm, at 2*sigma confidence level).Comment: ApJ, in press (LaTeX, 28 pages, 6 eps figures
Incidence and drug treatment of emotional distress after cancer diagnosis : a matched primary care case-control study
Notes This work is published under the standard license to publish agreement. After 12 months the work will become freely available and the license terms will switch to a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License.Peer reviewedPublisher PD
Mice deficient in CD38 develop an attenuated form of collagen type II-induced arthritis
CD38, a type II transmembrane glycoprotein expressed in many cells of the immune system, is involved in cell signaling, migration and differentiation. Studies in CD38 deficient mice (CD38 KO mice) indicate that this molecule controls inflammatory immune responses, although its involvement in these responses depends on the disease model analyzed. Here, we explored the role of CD38 in the control of autoimmune responses using chicken collagen type II (col II) immunized C57BL/6-CD38 KO mice as a model of collagen-induced arthritis (CIA). We demonstrate that CD38 KO mice develop an attenuated CIA that is accompanied by a limited joint induction of IL-1ÎČ and IL-6 expression, by the lack of induction of IFNÎł expression in the joints and by a reduction in the percentages of invariant NKT (iNKT) cells in the spleen. Immunized CD38 KO mice produce high levels of circulating IgG1 and low of IgG2a anti-col II antibodies in association with reduced percentages of Th1 cells in the draining lymph nodes. Altogether, our results show that CD38 participates in the pathogenesis of CIA controlling the number of iNKT cells and promoting Th1 inflammatory responses
Long-term adherence to IFN beta-1a treatment when using rebismart1device in patients with relapsing-remitting multiple sclerosis
The effectiveness of disease-modifying drugs in the treatment of multiple sclerosis is associated with adherence. RebiSmartÂź electronic device provides useful information about adherence to the treatment with subcutaneous (sc) interferon (IFN) Ă-1a (RebifÂź). The aim of the study was to determine long-term adherence to this treatment in patients with relapsing- remitting multiple sclerosis (RRMS). This retrospective multicentre observational study analysed 258 patients with RRMS who were receiving sc IFN Ă-1a (RebifÂź) treatment by using RebiSmartÂź until replacement (36 months maximum lifetime) or treatment discontinuation. Adherence was calculated with data (injection dosage, time, and date) automatically recorded by RebiSmartÂź. Patients in the study had a mean age of 41 years with a female proportion of 68%. Mean EDSS score at start of treatment was 1.8 (95% CI, 1.6-1.9). Overall adherence was 92.6%(95% CI, 90.6-94.5%). A total of 30.2% of patients achieved an adherence rate of 100%, 80.6% at least 90%, and only 13.2% of patients showed a suboptimal adherence (<80%). A total of 59.9% of subjects were relapse-free after treatment initiation. Among 106 subjects (41.1%) who experienced, on average, 1.4 relapses, the majority were mild (40.6%) or moderate (47.2%). Having experienced relapses from the beginning of the treatment was the only variable significantly related to achieving an adherence of at least 80% (OR = 3.06, 1.28-7.31). Results of this study indicate that sc IFN Ă-1a administration facilitated by RebiSmartÂź could lead to high rates of adherence to a prescribed dose regimen over 36 months
Factors associated with the development of septic shock in patients with candidemia: A post hoc analysis from two prospective cohorts
Background: Almost one third of the patients with candidemia develop septic shock. The understanding why some patients do and others do not develop septic shock is very limited. The objective of this study was to identify variables associated with septic shock development in a large population of patients with candidemia. Methods: A post hoc analysis was performed on two prospective, multicenter cohort of patients with candidemia from 12 hospitals in Spain and Italy. All episodes occurring from September 2016 to February 2018 were analyzed to assess variables associated with septic shock development defined according to The Third International Consensus Definition for Sepsis and Septic Shock (Sepsis-3). Results: Of 317 candidemic patients, 99 (31.2%) presented septic shock attributable to candidemia. Multivariate logistic regression analysis identifies the following factors associated with septic shock development: age > 50 years (OR 2.57, 95% CI 1.03-6.41, p = 0.04), abdominal source of the infection (OR 2.18, 95% CI 1.04-4.55, p = 0.04), and admission to a general ward at the time of candidemia onset (OR 0.21, 95% CI, 0.12-0.44, p = 0.001). Septic shock development was independently associated with a greater risk of 30-day mortality (OR 2.14, 95% CI 1.08-4.24, p = 0.02). Conclusions: Age and abdominal source of the infection are the most important factors significantly associated with the development of septic shock in patients with candidemia. Our findings suggest that host factors and source of the infection may be more important for development of septic shock than intrinsic virulence factors of organisms
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in âs=13âTeV pp collisions with the ATLAS detector
A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of âs=13ââTeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139ââfbâ1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015â2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
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