Accretion, Outflows, and Winds of Magnetized Stars

Many types of stars have strong magnetic fields that can dynamically influence the flow of circumstellar matter. In stars with accretion disks, the stellar magnetic field can truncate the inner disk and determine the paths that matter can take to flow onto the star. These paths are different in stars with different magnetospheres and periods of rotation. External field lines of the magnetosphere may inflate and produce favorable conditions for outflows from the disk-magnetosphere boundary. Outflows can be particularly strong in the propeller regime, wherein a star rotates more rapidly than the inner disk. Outflows may also form at the disk-magnetosphere boundary of slowly rotating stars, if the magnetosphere is compressed by the accreting matter. In isolated, strongly magnetized stars, the magnetic field can influence formation and/or propagation of stellar wind outflows. Winds from low-mass, solar-type stars may be either thermally or magnetically driven, while winds from massive, luminous O and B type stars are radiatively driven. In all of these cases, the magnetic field influences matter flow from the stars and determines many observational properties. In this chapter we review recent studies of accretion, outflows, and winds of magnetized stars with a focus on three main topics: (1) accretion onto magnetized stars; (2) outflows from the disk-magnetosphere boundary; and (3) winds from isolated massive magnetized stars. We show results obtained from global magnetohydrodynamic simulations and, in a number of cases compare global simulations with observations.Comment: 60 pages, 44 figure

Gaia Early Data Release 3: The celestial reference frame (Gaia-CRF3)

Context. Gaia-CRF3 is the celestial reference frame for positions and proper motions in the third release of data from the Gaia mission, Gaia DR3 (and for the early third release, Gaia EDR3, which contains identical astrometric results). The reference frame is defined by the positions and proper motions at epoch 2016.0 for a specific set of extragalactic sources in the (E)DR3 catalogue. Aims. We describe the construction of Gaia-CRF3 and its properties in terms of the distributions in magnitude, colour, and astrometric quality. Methods. Compact extragalactic sources in Gaia DR3 were identified by positional cross-matching with 17 external catalogues of quasi-stellar objects (QSO) and active galactic nuclei (AGN), followed by astrometric filtering designed to remove stellar contaminants. Selecting a clean sample was favoured over including a higher number of extragalactic sources. For the final sample, the random and systematic errors in the proper motions are analysed, as well as the radio-optical offsets in position for sources in the third realisation of the International Celestial Reference Frame (ICRF3). Results. Gaia-CRF3 comprises about 1.6 million QSO-like sources, of which 1.2 million have five-parameter astrometric solutions in Gaia DR3 and 0.4 million have six-parameter solutions. The sources span the magnitude range G = 13-21 with a peak density at 20.6 mag, at which the typical positional uncertainty is about 1 mas. The proper motions show systematic errors on the level of 12 μas yr-1 on angular scales greater than 15 deg. For the 3142 optical counterparts of ICRF3 sources in the S/X frequency bands, the median offset from the radio positions is about 0.5 mas, but it exceeds 4 mas in either coordinate for 127 sources. We outline the future of Gaia-CRF in the next Gaia data releases. Appendices give further details on the external catalogues used, how to extract information about the Gaia-CRF3 sources, potential (Galactic) confusion sources, and the estimation of the spin and orientation of an astrometric solution

Gaia Data Release 3: reflectance spectra of Solar System small bodies

Stars and planetary system

Gaia Data Release 3: the extragalactic content

Galaxie

Gaia Data Release 3: mapping the asymmetric disc of the Milky Way

Galaxie

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Comparative effectiveness of SGLT2i versus GLP1-RA on cardiovascular outcomes in routine clinical practice

Background: To investigate the comparative effectiveness of sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP1-RA) on cardiovascular outcomes in routine clinical practice, which have never been directly compared in head-to-head outcome trials.Methods: We compared outcomes of adults who newly started SGLT2i or GLP1-RA therapy in Stockholm, Sweden, during 2013-2019. The primary outcome was major adverse cardiovascular events (MACE), a composite of cardiovascular (CV) death, myocardial infarction and stroke. Secondary outcomes included the individual MACE components and hospitalization for heart failure. Cox regression with propensity score overlap weighting was used to estimate hazard ratios (HRs) with 95% confidence intervals and adjust for 57 covariates.Results: We included 12,375 individuals, of which 5489 initiated SGLT2i and 6886 GLP1-RA therapy, followed for median 1.6 years. Mean age was 61 years and 37.6% were women. Compared with GLP1-RA, SGLT2i new users had similar risk of MACE risk (adjusted HR 1.04; 95% CI 0.83-1.31). The adjusted HRs (95% CI) for SGLT2i vs. GLP1-RA were 0.80 (0.59-1.09) for heart failure hospitalization, 0.95 (0.58-1.55) for cardiovascular death, 0.91 (0.67-1.24) for myocardial infarction and 1.71 (1.14-2.59) for ischemic stroke (5-year absolute risk dif-ference for stroke 1.9% [95% CI 0.8-3.0]).Conclusions: In a largely primary-prevention population of people undergoing routine care, no differences were observed in MACE risk among initiators of SGLT2i and GLP1-RA. However, compared with GLP1RA, the use of SGLT2i was associated with an increased risk of ischemic stroke that was small in absolute magnitude.Clinical epidemiolog

Comparative effectiveness of SGLT2i versus GLP1-RA on cardiovascular outcomes in routine clinical practice

Background: To investigate the comparative effectiveness of sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP1-RA) on cardiovascular outcomes in routine clinical practice, which have never been directly compared in head-to-head outcome trials.Methods: We compared outcomes of adults who newly started SGLT2i or GLP1-RA therapy in Stockholm, Sweden, during 2013-2019. The primary outcome was major adverse cardiovascular events (MACE), a composite of cardiovascular (CV) death, myocardial infarction and stroke. Secondary outcomes included the individual MACE components and hospitalization for heart failure. Cox regression with propensity score overlap weighting was used to estimate hazard ratios (HRs) with 95% confidence intervals and adjust for 57 covariates.Results: We included 12,375 individuals, of which 5489 initiated SGLT2i and 6886 GLP1-RA therapy, followed for median 1.6 years. Mean age was 61 years and 37.6% were women. Compared with GLP1-RA, SGLT2i new users had similar risk of MACE risk (adjusted HR 1.04; 95% CI 0.83-1.31). The adjusted HRs (95% CI) for SGLT2i vs. GLP1-RA were 0.80 (0.59-1.09) for heart failure hospitalization, 0.95 (0.58-1.55) for cardiovascular death, 0.91 (0.67-1.24) for myocardial infarction and 1.71 (1.14-2.59) for ischemic stroke (5-year absolute risk dif-ference for stroke 1.9% [95% CI 0.8-3.0]).Conclusions: In a largely primary-prevention population of people undergoing routine care, no differences were observed in MACE risk among initiators of SGLT2i and GLP1-RA. However, compared with GLP1RA, the use of SGLT2i was associated with an increased risk of ischemic stroke that was small in absolute magnitude

Towards improved empirical isobase models of Holocene land uplift for mainland Scotland, UK

A new approach to modelling patterns of glacio-isostatic land uplift during the Holocene in mainland Scotland, UK, is described. The approach is based upon altitude measurements at the inner margin or locally highest point of raised estuarine surfaces dated by radiocarbon assay supported by microfossil analyses. 2241 altitudes have been analysed by a technique new to studies of former sea-levels, Gaussian Trend Surface Analysis, and isobase models for four Holocene shorelines: the Holocene Storegga Slide tsunami shoreline, abandoned rapidly circa 7900 sidereal years BP; the Main Postglacial shoreline, abandoned during circa 6400–7700 sidereal years BP; the Blairdrummond shoreline, abandoned during circa 4500–5800 sidereal years BP, and a speculative fourth shoreline, the Wigtown shoreline, abandoned during circa 1520–3700 sidereal years BP, are shown in a series of maps. The implications of the shoreline patterns for glaicio-isostasy in the area are discussed. It is maintained that the statistical technique used enables broad estimates to be made of nearshore sea surface change