217 research outputs found

    Pulmonary long-term consequences of COVID-19 infections after hospital discharge

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    Objectives: COVID-19 survivors are reporting residual abnormalities after discharge from the hospital. Limited information is available about this stage of recovery or the lingering effects of the virus on pulmonary function and inflammation. The aim of this study was to describe lung function and to identify biomarkers in serum and induced sputum samples from patients recovering from COVID-19 hospitalisation. Methods: Patients admitted to Spanish hospitals with laboratory-confirmed COVID-19 infection by a real-time PCR (RT-PCR) assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were recruited for this study. Each hospital screened their lists of discharged patients at least 45 days after symptom onset. SARS-CoV-2-infected patients were divided into mild/moderate and severe disease groups according to the severity of their symptoms during hospitalisation. Patients’ epidemiological and medical histories, comorbidities, chronic treatments, and laboratory parameters were evaluated. Pulmonary function tests, the standardised 6-minute walk test (6 MWT) and chest computed tomography (CT) were also performed. The levels of proteases, their inhibitors, and shed receptors were measured in serum and induced sputum samples. Results: A total of 100 patients with respiratory function tests were included in this study. The median number of days after the onset of symptoms was 104 (IQR 89.25, 126.75). COVID-19 was severe in 47% (47/100) of patients. CT was normal in 48% (48/100) of patients. Lung function was normal (FEV1 ≄80%, FVC ≄80%, FEV1/FVC ≄0.7, and diffusing capacity for carbon monoxide [DLCO] ≄80%) in 92% (92/100), 94% (94/100), 100% (100/100) and 48% (48/100) of patients, respectively. Multivariate analysis showed that a DLCO <80% (OR 5.92; 95%CI 2.28-15.37; p <0.0001) and a lower serum LDH level (OR 0.98; 95%CI 0.97-0.99) were associated with the severe disease group of SARS-CoV-2 during hospital stay. Conclusions: A diffusion deficit (DLCO <80%) was still present after hospital discharge and was associated with the most severe SARS-CoV-2 cases

    Giant Gravitons on AdS_4 x CP^3 and their Holographic Three-point Functions

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    We find a simple parametrization of the anti-symmetric giant graviton in AdS_4 x CP^3, first constructed in arXiv:1108.3084 [hep-th], dual to the anti-symmetric Schur polynomial involving two bi-fundamental complex scalar fields of ABJM theory. Using this parametrization we evaluate in a semi-classical approach the three-point function of two such giant gravitons and one point-like graviton considering both extremal and non-extremal configurations. We likewise discuss the case of the symmetric giant graviton in AdS_4 x CP^3. Finally, we provide an expression for the planar three-point function of chiral primary operators in ABJM at strong coupling and find that the results for the giant graviton three-point functions reduce to this expression in the point-like limit.Comment: 1+16 pages. v2 added a referenc

    Stereoscopic disambiguation of vector magnetograms: first applications to SO/PHI-HRT data

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    Spectropolarimetric reconstructions of the photospheric vector magnetic field are intrinsically limited by the 180∘^\circ-ambiguity in the orientation of the transverse component. So far, the removal of such an ambiguity has required assumptions about the properties of the photospheric field, which makes disambiguation methods model-dependent. The basic idea is that the unambiguous line-of-sight component of the field measured from one vantage point will generally have a non-zero projection on the ambiguous transverse component measured by the second telescope, thereby determining the ``true'' orientation of the transverse field. Such an idea was developed and implemented in the Stereoscopic Disambiguation Method (SDM), which was recently tested using numerical simulations. In this work we present a first application of the SDM to data obtained by the High Resolution Telescope (HRT) onboard Solar Orbiter during the March 2022 campaign, when the angle with Earth was 27 degrees. The method is successfully applied to remove the ambiguity in the transverse component of the vector magnetogram solely using observations (from HRT and from the Helioseismic and Magnetic Imager), for the first time. The SDM is proven to provide observation-only disambiguated vector magnetograms that are spatially homogeneous and consistent. A discussion about the sources of error that may limit the accuracy of the method, and of the strategies to remove them in future applications, is also presented.Comment: 32 pages, 12 figures, accepted in A&A on 09/07/202

    Magnetic fields inferred by Solar Orbiter: A comparison between SO/PHI-HRT and SDO/HMI

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    The High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager on board the Solar Orbiter spacecraft (SO/PHI) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) both infer the photospheric magnetic field from polarised light images. SO/PHI is the first magnetograph to move out of the Sun--Earth line and will provide unprecedented access to the Sun's poles. This provides excellent opportunities for new research wherein the magnetic field maps from both instruments are used simultaneously. We aim to compare the magnetic field maps from these two instruments and discuss any possible differences between them. We used data from both instruments obtained during Solar Orbiter's inferior conjunction on 7 March 2022. The HRT data were additionally treated for geometric distortion and degraded to the same resolution as HMI. The HMI data were re-projected to correct for the 3∘3^{\circ} separation between the two observatories. SO/PHI-HRT and HMI produce remarkably similar line-of-sight magnetograms, with a slope coefficient of 0.970.97, an offset below 11 G, and a Pearson correlation coefficient of 0.970.97. However, SO/PHI-HRT infers weaker line-of-sight fields for the strongest fields. As for the vector magnetic field, SO/PHI-HRT was compared to both the 720720-second and 9090-second HMI vector magnetic field: SO/PHI-HRT has a closer alignment with the 9090-second HMI vector. In the weak signal regime (<600< 600 G), SO/PHI-HRT measures stronger and more horizontal fields than HMI, very likely due to the greater noise in the SO/PHI-HRT data. In the strong field regime (≳600\gtrsim 600 G), HRT infers lower field strengths but with similar inclinations (a slope of 0.920.92) and azimuths (a slope of 1.021.02). The slope values are from the comparison with the HMI 9090-second vector.Comment: 10 pages, 5 figures, accepted for publication in A&A; manuscript is a part of Astronomy & Astrophysics special issue: Solar Orbiter First Results (Nominal Mission Phase

    Opposite cannabis-cognition associations in psychotic patients depending on family history

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    The objective of this study is to investigate cognitive performance in a first-episode psychosis sample, when stratifying the interaction by cannabis use and familial or non-familial psychosis. Hierarchical-regression models were used to analyse this association in a sample of 268 first-episode psychosis patients and 237 controls. We found that cannabis use was associated with worse working memory, regardless of family history. However, cannabis use was clearly associated with worse cognitive performance in patients with no family history of psychosis, in cognitive domains including verbal memory, executive function and global cognitive index, whereas cannabis users with a family history of psychosis performed better in these domains. The main finding of the study is that there is an interaction between cannabis use and a family history of psychosis in the areas of verbal memory, executive function and global cognition: that is, cannabis use is associated with a better performance in patients with a family history of psychosis and a worse performance in those with no family history of psychosis. In order to confirm this hypothesis, future research should explore the actual expression of the endocannabinoid system in patients with and without a family history of psychosis

    Wavefront error of PHI/HRT on Solar Orbiter at various heliocentric distances

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    We use wavefront sensing to characterise the image quality of the the High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (SO/PHI) data products during the second remote sensing window of the Solar Orbiter (SO) nominal mission phase. Our ultimate aims are to reconstruct the HRT data by deconvolving with the HRT point spread function (PSF) and to correct for the effects of optical aberrations on the data. We use a pair of focused--defocused images to compute the wavefront error and derive the PSF of HRT by means of a phase diversity (PD) analysis. The wavefront error of HRT depends on the orbital distance of SO to the Sun. At distances >0.5>0.5\,au, the wavefront error is small, and stems dominantly from the inherent optical properties of HRT. At distances <0.5<0.5\,au, the thermo-optical effect of the Heat Rejection Entrance Window (HREW) becomes noticeable. We develop an interpolation scheme for the wavefront error that depends on the thermal variation of the HREW with the distance of SO to the Sun. We also introduce a new level of image reconstruction, termed `aberration correction', which is designed to reduce the noise caused by image deconvolution while removing the aberrations caused by the HREW. The computed PSF via phase diversity significantly reduces the degradation caused by the HREW in the near-perihelion HRT data. In addition, the aberration correction increases the noise by a factor of only 1.451.45 compared to the factor of 33 increase that results from the usual PD reconstructions

    Evolutionary conservation and in vitro reconstitution of microsporidian iron–sulfur cluster biosynthesis

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    This work was supported by Marie Curie Postdoctoral Fellowships to T.A.W., E. H. and S. L., a European Research Council Advanced Investigator Grant (ERC-2010-AdG-268701) to T.M.E., and a Wellcome Trust Programme Grant (number 045404) to T.M.E. and J.M.L. R.L. acknowledges generous financial support from Deutsche Forschungsgemeinschaft (SFB 593, SFB 987, GRK 1216, LI 415/5), LOEWE program of state Hessen, Max-Planck Gesellschaft, von Behring-Röntgen StiftungMicrosporidians are a diverse group of obligate intracellular parasites that have minimized their genome content and simplified their sub-cellular structures by reductive evolution. Functional studies are limited because we lack reliable genetic tools for their manipulation. Here, we demonstrate that the cristae-deficient mitochondrion (mitosome) of the microsporidian Trachipleistophora hominis is the functional site of iron-sulphur cluster (ISC) assembly, which we suggest is the essential task of this organelle. Cell fractionation, fluorescence imaging and fine-scale immunoelectron microscopy demonstrate that mitosomes contain a complete pathway for [2Fe-2S] cluster biosynthesis that we biochemically reconstituted using purified recombinant mitosomal ISC proteins. Reconstitution proceeded as rapidly and efficiently as observed for yeast or fungal mitochondrial ISC components. Core components of the T. hominis cytosolic iron-sulphur protein assembly (CIA) pathway were also identified including the essential Cfd1-Nbp35 scaffold complex that assembles a [4Fe-4S] cluster as shown by spectroscopic methods in vitro. Phylogenetic analyses reveal that both the ISC and CIA biosynthetic pathways are predominantly bacterial, but their cytosolic and nuclear target Fe/S proteins are mainly archaeal. This mixed evolutionary history of the Fe/S-related proteins and pathways, and their strong conservation among highly reduced parasites, provides additional compelling evidence for the ancient chimeric ancestry of eukaryotes.Publisher PDFPeer reviewe

    The NEXT White (NEW) detector

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    Conceived to host 5 kg of xenon at a pressure of 15 bar in the fiducial volume, the NEXT-White apparatus is currently the largest high pressure xenon gas TPC using electroluminescent amplification in the world. It is also a 1:2 scale model of the NEXT-100 detector for Xe-136 beta beta 0 nu decay searches, scheduled to start operations in 2019. Both detectors measure the energy of the event using a plane of photomultipliers located behind a transparent cathode. They can also reconstruct the trajectories of charged tracks in the dense gas of the TPC with the help of a plane of silicon photomultipliers located behind the anode. A sophisticated gas system, common to both detectors, allows the high gas purity needed to guarantee a long electron lifetime. NEXT-White has been operating since October 2016 at the Laboratorio Subterraneo de Canfranc (LSC), in Spain. This paper describes the detector and associated infrastructures, as well as the main aspects of its initial operation
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