48 research outputs found

    Hubble spectroscopy of LB-1: comparison with B+black-hole and Be+stripped-star models

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    LB-1 has variously been proposed as either an X-ray dim B-type star plus black hole (B+BH) binary, or a Be star plus an inflated stripped star (Be+Bstr) binary. The Space Telescope Imaging Spectrograph (STIS) on board HST was used to obtain a flux-calibrated spectrum that is compared with non-LTE spectral energy distributions (SED) and line profiles for the proposed models. The Hubble data, together with the Gaia EDR3 parallax, provide tight constraints on the properties and stellar luminosities of the system. In the case of the Be+Bstr model we adopt the published flux ratio for the Be and Bstr stars, re-determine the Teff_{eff} of the Bstr using the silicon ionization balance, and infer Teff for the Be star from the fit to the SED. We derive stellar parameters consistent with previous results, but with greater precision enabled by the Hubble SED. While the Be+Bstr model is a better fit to the HeI lines and cores of the Balmer lines in the optical, the B+BH model provides a better fit to the Si iv resonance lines in the UV. The analysis also implies that the Bstr star has roughly twice solar silicon abundance, difficult to reconcile with a stripped star origin. The Be star on the other hand has a rather low luminosity, and a spectroscopic mass inconsistent with its possible dynamical mass. The fit to the UV can be significantly improved by reducing the Teff_{eff} and radius of the Be star, though at the expense of leading to a different mass ratio. In the B+BH model, the single B-type spectrum is a good match to the UV spectrum. Adopting a mass ratio of 5.1±\pm0.1 (Liu et al. 2020) implies a BH mass of \sim218+9M^{+9}_{-8}M_{\odot}.Comment: 8 pages, 7 figures, 1 online table In press with Astronomy & Astrophysic

    Gender differences in addiction severity

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    Gender has been associated with substance use disorders (SUD). However, there are few studies that have evaluated gender differences in a global and a standardized way, and with a large sample of patients with SUD. Our goal is to analyze the role of gender in addiction severity throughout multiple life domains, using the Addiction Severity Index-6 (ASI-6). A naturalistic, multicenter and prospective study was conducted. A total of 221 patients with SUD (80.1% men) were interviewed with the ASI-6. Our results indicate that the Recent Summary Scores (RSSs) of men and women are similar, with the exception of Psychiatric and Partner- Problems, where women showed higher severity (p = .017 and p = .013, respectively). Statistically significant gender differences were found in certain aspects of the ASI-6 domains: men have more problems of physical health, legal issues, and alcohol and other substance use; and woman score higher in problems of mental health, social network, subjective evaluations of SUD consequences, and treatment needs. These results should be taken into account to improve the identification, prevention, and treatment of SUD.Se ha descrito que el género es un factor que condiciona los trastornos por uso de sustancias (TUS). Sin embargo, hay pocos estudios que hayan evaluado esas diferencias de género de manera global, estandarizada y en una muestra amplia de pacientes con TUS. Nuestro objetivo es analizar el rol del género en la gravedad de la adicción a través de los diversos dominios de vida mediante el Addiction Severity Index-6 (ASI-6). Se llevó a cabo un estudio naturalístico, multicéntrico y prospectivo con una muestra compuesta por 221 pacientes con TUS (80,1% hombres). Los participantes fueron entrevistados con el ASI-6. Los resultados han mostrado que las Puntuaciones Sumarias Recientes (PSRs) son similares entre hombres y mujeres a excepción de las correspondientes a Salud mental y Pareja- Problemas, donde las mujeres presentan mayor gravedad (p = 0,017 y p = 0,013, respectivamente). Por otra parte, se han encontrado diferencias estadísticamente significativas e diversos aspectos concretos de las áreas contempladas por el ASI-6, que indican que los hombres presentan más problemas en cuanto a salud física, cuestiones legales y uso de alcohol y drogas, y la mujeres en salud mental, red social y la valoración subjetiva sobre las consecuencias del TUS y la necesidad de tratamiento. Estos resultados deben tenerse en cuenta a la hora de implementar una mejora en la identificación, prevención y tratamiento de los TUS

    The balance of power: accretion and feedback in stellar mass black holes

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    In this review we discuss the population of stellar-mass black holes in our galaxy and beyond, which are the extreme endpoints of massive star evolution. In particular we focus on how we can attempt to balance the available accretion energy with feedback to the environment via radiation, jets and winds, considering also possible contributions to the energy balance from black hole spin and advection. We review quantitatively the methods which are used to estimate these quantities, regardless of the details of the astrophysics close to the black hole. Once these methods have been outlined, we work through an outburst of a black hole X-ray binary system, estimating the flow of mass and energy through the different accretion rates and states. While we focus on feedback from stellar mass black holes in X-ray binary systems, we also consider the applicability of what we have learned to supermassive black holes in active galactic nuclei. As an important control sample we also review the coupling between accretion and feedback in neutron stars, and show that it is very similar to that observed in black holes, which strongly constrains how much of the astrophysics of feedback can be unique to black holes.Comment: To be published in Haardt et al. Astrophysical Black Holes. Lecture Notes in Physics. Springer 201

    BOOTES-IR: Near IR follow-up GRB observations by a robotic system

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    “BOOTES-IR” is the extension of the BOOTES experiment, which operates in Southern Spain since 1998, to the near IR (NIR). The goal is to follow up the early stage of the gamma ray burst (GRB) afterglow emission in the NIR, alike BOOTES does already at optical wavelengths. The scientific case that drives the BOOTES-IR performance is the study of GRBs with the support of spacecraft like INTEGRAL, SWIFT and GLAST. Given that the afterglow emission in both, the NIR and the optical, in the instances immediately following a GRB, is extremely bright (reached V = 8.9 in one case), it should be possible to detect this prompt emission at NIR wavelengths too. The combined observations by BOOTES-IR and BOOTES-1 and BOOTES-2 will allow for real time identification of trustworthy candidates to have a high redshift (z > 5). It is expected that, few minutes after a GRB, the IR magnitudes be H ∼ 7–10, hence very high quality spectra can be obtained for objects as far as z = 10 by larger instruments

    Mental health care for irregular migrants in Europe: Barriers and how they are overcome

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    Sub-second infrared variability from the archetypal accreting neutron star 4U 1728−34

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    We report on the first simultaneous high-time resolution X-ray and infrared (IR) observations of a neutron star low mass X-ray binary in its hard state. We performed ≈ 2 h of simultaneous observations of 4U 1728−34 using HAWK-I@VLT, XMM– Newton, and NuSTAR. The source displayed significant X-ray and IR variability down to sub-second time-scales. By measuring the cross-correlation function between the IR and X-ray lightcurves, we discovered a significant correlation with an IR lead of ≈ 30–40 ms with respect to the X-rays. We analysed the X-ray energy dependence of the lag, finding a marginal increase towards higher energies. Given the sign of the lag, we interpret this as possible evidence of Comptonization from external seed photons. We discuss the origin of the IR seed photons in terms of cyclo-synchrotron radiation from an extended hot flow. Finally, we also observed the IR counterpart of a type-I X-ray burst, with a delay of ≈ 7.2 s. Although some additional effects may be at play, by assuming that this lag is due to light travel time between the central object and the companion star, we find that 4U 1728−34 must have an orbital period longer than 3 h and an inclination higher than 8◦

    Impact of FLT3–ITD Mutation Status and Its Ratio in a Cohort of 2901 Patients Undergoing Upfront Intensive Chemotherapy: A PETHEMA Registry Study

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    FLT3–ITD results in a poor prognosis in terms of overall survival (OS) and relapse-free survival (RFS) in acute myeloid leukemia (AML). However, the prognostic usefulness of the allelic ratio (AR) to select post-remission therapy remains controversial. Our study focuses on the prognostic impact of FLT3–ITD and its ratio in a series of 2901 adult patients treated intensively in the pre-FLT3 inhibitor era and reported in the PETHEMA registry. A total of 579 of these patients (20%) harbored FLT3–ITD mutations. In multivariate analyses, patients with an FLT3–ITD allele ratio (AR) of >0.5 showed a lower complete remission (CR rate) and OS (HR 1.47, p = 0.009), while AR > 0.8 was associated with poorer RFS (HR 2.1; p 0.5). Using the maximally selected log-rank statistics, we established an optimal cutoff of FLT3–ITD AR of 0.44 for OS, and 0.8 for RFS. We analyzed the OS and RFS according to FLT3–ITD status in all patients, and we found that the group of FLT3–ITD-positive patients with AR 0.44, allo-HSCT was superior to auto-HSCT in terms of OS and RFS. This study provides more evidence for a better characterization of patients with AML harboring FLT3–ITD mutations.Depto. de MedicinaFac. de MedicinaTRUEInstituto de Salud Carlos IIIFundación CRIS Contra el CáncerInstituto de Investigación Hospital 12 de OctubreUnión Europeapu

    Resumen ejecutivo del Documento de Consenso de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEIMC) y de la Asociación Española de Cirujanos (AEC) en profilaxis antibiótica en cirugía

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    La profilaxis antibiótica en cirugía es una de las medidas más eficaces para la prevención de la infección de localización quirúrgica, aunque su uso es con frecuencia inadecuado, pudiendo incrementar el riesgo de infección, toxicidades y resistencias bacterianas. Debido al avance en las técnicas quirúrgicas y la emergencia de microorganismos multirresistentes las actuales pautas de profilaxis precisan ser revisadas. La Sociedad Española de Enfermedades Infecciosas (SEIMC), conjuntamente con la Asociación Española de Cirujanos (AEC) ha revisado y actualizado las recomendaciones de profilaxis antimicrobiana para adaptarlas a cada tipo de intervención quirúrgica y a la epidemiología actual. En este documento se recogen las recomendaciones de los antimicrobianos utilizados en profilaxis en los diferentes procedimientos, las dosis, la duración, la profilaxis en huéspedes especiales, y en situación epidemiológica de multirresistencia, de tal forma que permitan un manejo estandarizado, un uso racional, seguro y efectivo de los mismos en la cirugía electiva. Antibiotic prophylaxis in surgery is one of the most effective measures for preventing surgical site infection, although its use is frequently inadequate and may even increase the risk of infection, toxicities and antimicrobial resistance. As a result of advances in surgical techniques and the emergence of multidrug-resistant organisms, the current guidelines for prophylaxis need to be revised. The Sociedad Española de Enfermedades Infecciosas (Spanish Society of Infectious Diseases and Clinical Microbiology) (SEIMC) together with the Asociación Española de Cirujanos (Spanish Association of Surgeons) (AEC) have revised and updated the recommendations for antibiotic prophylaxis in surgery to adapt them to any type of surgical intervention and to current epidemiology. This document gathers together the recommendations on antimicrobial prophylaxis in the various procedures, with doses, duration, prophylaxis in special patient groups, and in epidemiological settings of multidrug resistance to facilitate standardized management and the safe, effective and rational use of antibiotics in elective surgery
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