23,189 research outputs found
The gluon propagator from large asymmetric lattices
The Landau-gauge gluon propagator is computed for the SU(3) gauge theory on
lattices up to a size of . We use the standard Wilson action
at and compare our results with previous computations using large
asymmetric and symmetric lattices. In particular, we focus on the impact of the
lattice geometry and momentum cuts to achieve compatibility between data from
symmetric and asymmetric lattices for a large range of momenta.Comment: Poster presented at Lattice2007, Regensburg, July 30 - August 4, 200
Chronic treatment with hydroxychloroquine and SARS-CoV-2 infection
Hydroxychloroquine sulfate (HCQ) is being scrutinized for repositioning in the treatment and prevention of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This antimalarial drug is also chronically used to treat patients with autoimmune diseases. By analyzing the Portuguese anonymized data on private and public based medical prescriptions we have identified all cases chronically receiving HCQ for the management of diseases, such as systemic lupus erythematosus, rheumatoid arthritis, and other autoimmune diseases. Additionally, we have detected all laboratory confirmed cases of SARS-CoV-2 infection and all laboratory confirmed negative cases in the Portuguese population (mandatorily registered in a centrally managed database). Cross linking the two sets of data has allowed us to compare the proportion of HCQ chronic treatment (at least 2 grams per month) in laboratory confirmed cases of SARS-CoV-2 infection with laboratory confirmed negative cases. Out of 26 815 SARS-CoV-2 positive patients, 77 (0.29%) were chronically treated with HCQ, while 1215 (0.36%) out of 333 489 negative patients were receiving it chronically (P = .04). After adjustment for age, sex, and chronic treatment with corticosteroids and/or immunosuppressants, the odds ratio of SARS-CoV-2 infection for chronic treatment with HCQ has been 0.51 (0.37-0.70). Our data suggest that chronic treatment with HCQ confer protection against SARS-CoV-2 infection.info:eu-repo/semantics/publishedVersio
Comparison of solar radio and EUV synoptic limb charts during the present solar maximum
The present solar cycle is particular in many aspects: it had a delayed
rising phase, it is the weakest of the last 100 years, and it presents two
peaks separated by more than one year. To understand the impact of these
characteristics on the solar chromosphere and coronal dynamics, images from a
wide wavelength range are needed. In this work we use the 17~GHz radio
continuum, formed in the upper chromosphere and the EUV lines 304 and
171~{\AA}, that come from the transition region (He II) and the corona (Fe IX,
X), respectively. We analyze daily images at 304 and 171~{\AA} obtained by the
Atmospheric Imaging Assembly (AIA). The 17~GHz maps were obtained by the
Nobeyama Radioheliograph (NoRH). To construct synoptic limb charts, we
calculated the mean emission of delimited limb areas with 100" wide and angular
separation of . At the equatorial region, the results show an
hemispheric asymmetry of the solar activity. The northern hemisphere dominance
is coincident with the first sunspot number peak, whereas the second peak
occurs concurrently with the increase in the activity at the south. The polar
emission reflects the presence of coronal holes at both EUV wavelengths,
moreover, the 17~GHz polar brightenings can be associated with the coronal
holes. Until 2013, both EUV coronal holes and radio polar brightenings were
more predominant at the south pole. Since then they have not been apparent in
the north, but thus appear in the beginning of 2015 in the south as observed in
the synoptic charts. This work strengthens the association between coronal
holes and the 17~GHz polar brightenings as it is evident in the synoptic limb
charts, in agreement with previous case study papers. The enhancement of the
radio brightness in coronal holes is explained by the presence of bright
patches closely associated with the presence of intense unipolar magnetic
fields.Comment: 6 pages, 5 figures. Acccepted for publication in Astronomy &
Astrophysic
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