21 research outputs found

    Diagnosing the interstellar medium of galaxies with far-infrared emission lines I. The [C II] 158 microns line at z~0

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    Atomic fine structure lines have been detected in the local Universe and at high redshifts over the past decades. The [C II] emission line at 158 μ\mum is an important observable as it provides constraints on the interstellar medium (ISM) cooling processes. We develop a physically motivated framework to simulate the production of far-infrared line emission from galaxies in a cosmological context. This first paper sets out our methodology and describes its first application, simulating the [C II] 158 μ\mum line emission in the local Universe. We combine the output from EAGLE cosmological hydrodynamical simulations with a multi-phase model of the ISM. Gas particles are divided into three phases: dense molecular gas, neutral atomic gas and diffuse ionised gas (DIG). We estimate the [C II] line emission from the three phases using a set of Cloudy cooling tables. Our results agree with previous findings regarding the contribution of these three ISM phases to the [C II] emission. Our model shows good agreement with the observed L[CII]{\rm L_{[C II]}}-star formation rate (SFR) relation in the local Universe within 0.4 dex scatter. The fractional contribution to the [C II] line from different ISM phases depends on the total SFR and metallicity. The neutral gas phase dominates the [C II] emission in galaxies with SFR0.01\rm{SFR}\sim0.01-1Myr11\,\rm{M_{\odot}}\,\rm{yr^{-1}}, but the ionised phase dominates at lower SFRs. Galaxies above solar metallicity exhibit lower L[CII]{\rm L_{[C II]}}/SFR ratios for the neutral phase. In comparison, the L[CII]{\rm L_{[C II]}}/SFR ratio in the DIG is stable when metallicity varies. We suggest that the reduced size of the neutral clouds, caused by increased SFRs, is the likely cause for the L[CII]{\rm L_{[C II]}} deficit at high infrared luminosities, although EAGLE simulations do not reach these luminosities at z=0z=0.Comment: Accepted for publication in A&A; 16 pages, 11 figures, 4 tables (plus appendix

    The AGN Luminosity Fraction in Merging Galaxies

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    Galaxy mergers are key events in galaxy evolution, often causing massive starbursts and fueling active galactic nuclei (AGN). In these highly dynamic systems, it is not yet precisely known how much starbursts and AGN respectively contribute to the total luminosity, at what interaction stages they occur, and how long they persist. Here we estimate the fraction of the bolometric infrared (IR) luminosity that can be attributed to AGN by measuring and modeling the full ultraviolet to far-infrared spectral energy distributions (SEDs) in up to 33 broad bands for 24 merging galaxies with the Code for Investigating Galaxy Emission. In addition to a sample of 12 confirmed AGN in late-stage mergers, found in the InfraredInfrared ArrayArray SatelliteSatellite Revised Bright Galaxy Sample or Faint Source Catalog, our sample includes a comparison sample of 12 galaxy mergers from the SpitzerSpitzer Interacting Galaxies Survey, mostly early-stage. We perform identical SED modeling of simulated mergers to validate our methods, and we supplement the SED data with mid-IR spectra of diagnostic lines obtained with SpitzerSpitzer InfraRed Spectrograph. The estimated AGN contributions to the IR luminosities vary from system to system from 0% up to 91% but are significantly greater in the later-stage, more luminous mergers, consistent with what is known about galaxy evolution and AGN triggering.Comment: 26 pages, 10 figure

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    The viewing angle in AGN SED models, a data-driven analysis

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    The validity of the unified active galactic nuclei (AGN) model has been challenged in the last decade, especially when different types of AGNs are considered to only differ in the viewing angle to the torus. We aim to assess the importance of the viewing angle in classifying different types of Seyfert galaxies in spectral energy distribution (SED) modelling. We retrieve photometric data from publicly available astronomical databases: CDS and NED, to model SEDs with X-CIGALE in a sample of 13 173 Seyfert galaxies located at redshift range from z = 0 to z = 3.5, with a median redshift of z ≍ 0.2. We assess whether the estimated viewing angle from the SED models reflects different Seyfert classifications. Two AGN models with either a smooth or clumpy torus structure are adopted in this paper. We find that the viewing angle in Type-1 AGNs is better constrained than in Type-2 AGNs. Limiting the viewing angles representing these two types of AGNs do not affect the physical parameter estimates such as star-formation rate (SFR) or AGN fractional contribution (fAGN). In addition, the viewing angle is not the most discriminating physical parameter to differentiate Seyfert types. We suggest that the observed and intrinsic AGN disc luminosity can: i) be used in z < 0.5 studies to distinguish between Type-1 and Type-2 AGNs, and ii) explain the probable evolutionary path between these AGN types. Finally, we propose the use of X-CIGALE for AGN galaxy classification tasks. All data from the 13 173 SED fits are available at Zenodo.

    Cuentos que construyen paz

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    Esta propuesta se enmarca en el Proyecto Comunidades Educativas que Construyen Paz, del Instituto de Estudios Latinoamericanos (IDELA), cuyo propósito es facilitar procesos pedagógicos para la paz con comunidades educativas, por medio de una metodología lúdica y participativa, con el fin de promover la construcción de una cultura de paz en los espacios de convivencia cotidianos.Este libro es el resultado de un proceso que se fue tejiendo durante el 2021, el Festival para la Paz, el cual se realiza como una forma de contribuir a la creación y difusión de espacios participativos, lúdicos y creativos para instar a la paz desde las comunidades educativas. Esto, a modo de ir constituyendo una red con ideas novedosas que dan forma a dichos cuentos, constructores de paz. La creación y elaboración de cuentos fue una apuesta con equipos interdisciplinarios, niñas y niños de las escuelas públicas de la Regional de Heredia del Ministerio de Educación Pública de Costa Rica: Escuela Finca Guararí, Escuela Miguel Aguilar Bonilla, Escuela Rubén Darío y Escuela Santiago.This book is the result of a process that was woven during 2021, the Festival for Peace, which is carried out as a way to contribute to the creation and dissemination of participatory, playful and creative spaces to encourage peace from the educational communities. This, as a way of building a network with innovative ideas that give shape to these stories, peace builders. The creation and elaboration of stories was a bet with interdisciplinary teams, girls and boys of the public schools of the Heredia Regional of the Ministry of Public Education of Costa Rica: Finca Guararí School, Miguel Aguilar Bonilla School, Rubén Darío School and Santiago School.Instituto de Estudios Latinoamericano

    Inequalities in screening policies and perioperative protection for patients with acute appendicitis during the pandemic: Subanalysis of the ACIE Appy study

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    Safety of hospital discharge before return of bowel function after elective colorectal surgery

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    Background: Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function.Methods: A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien-Dindo classification system.Results: A total of 3288 patients were included in the analysis, of whom 301 (9.2 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4-7) and 7 (6-8) days respectively (P &lt; 0.001). There were no significant differences in rates of readmission between these groups (6.6 versus 8.0 per cent; P = 0.499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0.90, 95 per cent c.i. 0.55 to 1.46; P = 0.659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34.7 versus 39.5 per cent; major 3.3 versus 3.4 per cent; P = 0.110).Conclusion: Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients

    Timing of nasogastric tube insertion and the risk of postoperative pneumonia: an international, prospective cohort study

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    Aim: Aspiration is a common cause of pneumonia in patients with postoperative ileus. Insertion of a nasogastric tube (NGT) is often performed, but this can be distressing. The aim of this study was to determine whether the timing of NGT insertion after surgery (before versus after vomiting) was associated with reduced rates of pneumonia in patients undergoing elective colorectal surgery. Method: This was a preplanned secondary analysis of a multicentre, prospective cohort study. Patients undergoing elective colorectal surgery between January 2018 and April 2018 were eligible. Those receiving a NGT were divided into three groups, based on the timing of the insertion: routine NGT (inserted at the time of surgery), prophylactic NGT (inserted after surgery but before vomiting) and reactive NGT (inserted after surgery and after vomiting). The primary outcome was the development of pneumonia within 30 days of surgery, which was compared between the prophylactic and reactive NGT groups using multivariable regression analysis. Results: A total of 4715 patients were included in the analysis and 1536 (32.6%) received a NGT. These were classified as routine in 926 (60.3%), reactive in 461 (30.0%) and prophylactic in 149 (9.7%). Two hundred patients (4.2%) developed pneumonia (no NGT 2.7%; routine NGT 5.2%; reactive NGT 10.6%; prophylactic NGT 11.4%). After adjustment for confounding factors, no significant difference in pneumonia rates was detected between the prophylactic and reactive NGT groups (odds ratio 1.03, 95% CI 0.56–1.87, P = 0.932). Conclusion: In patients who required the insertion of a NGT after surgery, prophylactic insertion was not associated with fewer cases of pneumonia within 30 days of surgery compared with reactive insertion
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