17 research outputs found
The Bulge Radial Velocity Assay for RR Lyrae stars (BRAVA-RR) DR2: a Bimodal Bulge?
Radial velocities of 2768 fundamental mode RR Lyrae stars (RRLs) toward the
Southern Galactic bulge are presented, spanning the southern bulge from -8 < l
< +8 and -3 < b <-6. Distances derived from the pulsation properties of the
RRLs are combined with Gaia proper motions to give constraints on the orbital
motions of 1389 RRLs. The majority (~75%) of the bulge RRLs have orbits
consistent with these stars being permanently bound to <3.5 kpc from the
Galactic Center, similar to the bar. However, unlike the bulge giants, the RRLs
exhibit slower rotation and a higher velocity dispersion. The higher velocity
dispersion arises almost exclusively from halo interlopers passing through the
inner Galaxy. We present 82 stars with space velocities > 500 km/s and find
that the majority of these high-velocity stars are halo interlopers; it is
unclear if a sub-sample of these stars with similar space velocities have a
common origin. Once the 25% of the sample represented by halo interlopers is
cleaned, we can clearly discern two populations of bulge RRLs in the inner
Galaxy. One population of RRLs is not as tightly bound to the Galaxy (but is
still confined to the inner ~3.5 kpc), and is both spatially and kinematically
consistent with the barred bulge. The second population is more centrally
concentrated and does not trace the bar. One possible interpretation is that
this population was born prior to bar formation, as its spatial location,
kinematics and pulsation properties suggest, possibly from an accretion event
at high redshift.Comment: accepted for publication in the Astronomical Journa
Dynamically Tagged Groups of Very Metal-poor Halo Stars from the HK and Hamburg/ESO Surveys
© 2020. The American Astronomical Society. All rights reserved.We analyze the dynamical properties of ∼1500 very metal-poor (VMP; [Fe/H] ≲−2.0) halo stars, based primarily on medium-resolution spectroscopic data from the HK and Hamburg/ESO surveys. These data, collected over the past thirty years, are supplemented by a number of calibration stars and other small samples, along with astrometric information from Gaia DR2. We apply a clustering algorithm to the 4-D energy-action space of the sample, and identify a set of 38 Dynamically Tagged Groups (DTGs), containing between 5 and 30 member stars. Many of these DTGs can be associated with previously known prominent substructures such as Gaia-Sausage/Enceladus (GSE), Sequoia, the Helmi Stream (HStr), and Thamnos. Others are associated with previously identified smaller dynamical groups of stars and streams. We identify 10 new DTGs as well, many of which have strongly retrograde orbits. We also investigate possible connections between our DTGs and ∼300 individual r-process-enhanced (RPE) stars \textbf{from a recent literature compilation}. We find that several of these objects have similar dynamical properties to GSE (5), the HStr (4), Sequoia (1), and Rg5 (1), indicating that their progenitors might have been important sources of RPE stars in the Galaxy. Additionally, a number of our newly identified DTGs are shown to be associated with at least two RPE stars each (DTG-2: 3, DTG-7: 2; DTG-27: 2). Taken as a whole, these results are consistent with ultra-faint and/or dwarf spheroidal galaxies as birth environments in which r-process nucleosynthesis took place, and then were disrupted by the Milky Way.Peer reviewe
Long-term outcomes of the global tuberculosis and COVID-19 co-infection cohort
Background: Longitudinal cohort data of patients with tuberculosis (TB) and coronavirus disease 2019 (COVID-19) are lacking. In our global study, we describe long-term outcomes of patients affected by TB and COVID-19. Methods: We collected data from 174 centres in 31 countries on all patients affected by COVID-19 and TB between 1 March 2020 and 30 September 2022. Patients were followed-up until cure, death or end of cohort time. All patients had TB and COVID-19; for analysis purposes, deaths were attributed to TB, COVID-19 or both. Survival analysis was performed using Cox proportional risk-regression models, and the log-rank test was used to compare survival and mortality attributed to TB, COVID-19 or both. Results: Overall, 788 patients with COVID-19 and TB (active or sequelae) were recruited from 31 countries, and 10.8% (n=85) died during the observation period. Survival was significantly lower among patients whose death was attributed to TB and COVID-19 versus those dying because of either TB or COVID-19 alone (p<0.001). Significant adjusted risk factors for TB mortality were higher age (hazard ratio (HR) 1.05, 95% CI 1.03-1.07), HIV infection (HR 2.29, 95% CI 1.02-5.16) and invasive ventilation (HR 4.28, 95% CI 2.34-7.83). For COVID-19 mortality, the adjusted risks were higher age (HR 1.03, 95% CI 1.02-1.04), male sex (HR 2.21, 95% CI 1.24-3.91), oxygen requirement (HR 7.93, 95% CI 3.44-18.26) and invasive ventilation (HR 2.19, 95% CI 1.36-3.53). Conclusions: In our global cohort, death was the outcome in >10% of patients with TB and COVID-19. A range of demographic and clinical predictors are associated with adverse outcomes
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Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
The original version of this article unfortunately contained a mistake
Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
Comparative analysis of quality of life of patients with dermatological problems: teledermatology versus face-to-face dermatology
The health-related quality of life (HRQoL) of the patients cared for with teledermatology (TD) services was analyzed as compared with face-to-face dermatology (F-F/D) at the hospital. This study was a controlled, non-blinded, intra-level, and multicenter randomized clinical trial, with a 6-month follow-up. A total of 450 patients were randomly assigned to two different groups. The Spanish version of the generic EuroQol-5-dimensions-5-Levels (EQ-5D-5L) questionnaire and the specific Skindex-29 questionnaire were used at 0 and 6 months. The number of primary care visits (2.24 TD; 1.68 F-F/D) and number of hospital visits (0.01 TD; 1.48 F-F/D) were statistically significant. It was observed that from month 0 onwards, the users included in the F-F/D group self-perceived a lower HRQoL than the users included in the TD group (Skindex-29 total: p ≤ 0.00; EQ-5D-5L VAS = p ≤ 0.00; EQ-5D-5L utilities = p ≤ 0.00). At the end of the study, the patients included in the F-F/D group still obtained lower scores in their perception of HRQoL, as compared to those included in the other type of follow-up (Skindex-29 total: p ≤ 0.00; EQ-5D-5L VAS = p ≤ 0.00; EQ-5D-5L utilities = p ≤ 0.00). TD was an effective diagnosis and follow-up tool. At the end of the study period, the HRQoL of the patients in both groups was significantly higher as compared to their baseline levels. Additionally, both the general and specific HRQoL perceived by the TD patients was higher than the F-F/D group from the start of the study
Cell damage detection using Escherichia coli reporter plasmids: fluorescent and colorimetric assays
Bacterial reporter assays are powerful tools used to study the effect of different compounds that affect the physiology of cellular processes. Most bacterial reporters are luciferase based and can be monitored in real time. In the present study we designed and implemented two sets of Escherichia coli bacterial reporter assays, using a multicopy plasmid system. Each reporter strain was constructed using either green fluorescent protein or β-galactosidase (LacZ) proteins. The designed reporter strains are capable of responding in a specific manner to molecules that either oxidative stress, or membrane, protein, or DNA damage. In order to respond to the desired stimulus, promoter sequences from E. coli were used. These sequences correspond to the promoter of the major catalase (KatG) activated with cellular oxidative damage, the promoter of the β-hydroxydecanoyl-ACP dehydrase (FabA) which is activated with membrane perturbation, the promoter of DNA recombinase (RecA) which is activated by DNA lesions. For protein misfolding, the promoter of the heat-shock responsive chaperon (DnaK) was used. Our constructs displayed activation to damage from specific stimuli, and low response to nonspecific stimuli was detected. Our results suggest that these types of bacterial reporter strains can be used in semiquantitative (fluorometric) and qualitative (β-galactosidase activity) studies of different xenobiotic substances and pollutants.Los ensayos con periodistas bacterianos son potentes herramientas utilizadas para estudiar el efecto de diferentes compuestos que afectan la fisiología de los procesos celulares. La mayoría de los reporteros bacterianos están basados en luciferasa y pueden ser monitoreados en tiempo real. En el presente estudio hemos diseñado e implementado dos series de Escherichia coli bacteriana para reportar ensayos, utilizando un sistema de plásmido multicopia. Cada cepa informadora se construyó usando proteínas fluorescentes verdes o proteínas de β-galactosidasa (LacZ). Las cepas informadoras diseñadas son capaces de responder de una manera específica a las moléculas ya sea el estrés oxidativo, o membrana, proteína o daño del ADN. Con el fin de responder al estímulo deseado, se usaron secuencias promotoras de E. coli. Estas secuencias corresponden al promotor de la catalasa mayor (KatG) activada con daño oxidativo celular, el promotor de la deshidrasa β-hidroxidecanoil-ACP (FabA) que se activa con perturbación de membrana, el promotor de ADN recombinasa (RecA) que se activa por lesiones de ADN. Para el repliegue erróneo de proteínas, se utilizó el promotor del chaperón sensible al choque térmico (DnaK). Nuestros constructos mostraron la activación de daño de estímulos específicos, y la baja respuesta a los estímulos no específicos se detectó. Nuestros resultados sugieren que estos tipos de cepas de reportero bacteriano pueden ser utilizados en estudios semicuantitativos (fluorométricos) y cualitativos (actividad β-galactosidasa) de diferentes sustancias xenobióticas y contaminantes
Phase-space Properties and Chemistry of the Sagittarius Stellar Stream Down to the Extremely Metal-poor ([Fe/H] . −3) Regime
In this work, we study the phase-space and chemical properties of Sagittarius (Sgr) stream, the tidal tails produced by the ongoing destruction of Sgr dwarf spheroidal (dSph) galaxy, focusing on its very metal-poor (VMP; [Fe/H] 200 VMP stars. We find the leading arm (b > 0) of Sgr stream to be more metal-poor, by ∼0.2 dex, than the trailing one (b 2 Gyr ago) have present-day phase-space properties similar to lower-metallicity stream stars. Conversely, those stripped more recently ( −1) members of the stream. Such correlation between kinematics and chemistry can be explained by the existence of a dynamically hotter, less centrally-concentrated, and more metal-poor population in Sgr dSph prior to its disruption, implying that this galaxy was able to develop a metallicity gradient before its accretion. Finally, we discovered several carbon-enhanced metal-poor ([C/Fe] > +0.7 and [Fe/H] ≤ −1.5) stars in Sgr stream, which is in tension with current observations of its remaining core where such objects are not found