32 research outputs found
Accreting Supermassive Black Holes in the First Billion Years: Impact on their Environments from Parsecs to Megaparsecs.
Studying the environments of quasars in the first Gyr of the universe, or at z > 5.5, is crucial to understand their growth and evolution from such early times. These massive quasars with ∼ 10^8 − 10^9 Solar mass black holes are predicted to be born in the most massive halos of the underlying dark matter distribution and thus would be immersed in protoclusters of galaxies. However, the impact of a quasar’s powerful radiation on the formation and growth of galaxies in its Mpc-scale environment is still debated observationally. Additionally, the different components contributing to the quasar activity from subpc- to kpc-scales can affect the gas and dust used to form stars in its host galaxy, thus impacting the black hole – host galaxy co-evolution. This thesis aims at providing more understanding of the different scales of quasar environments by investigating two exemplary quasars. We investigated the luminous quasar ULAS J1342+0928 at z = 7.54 and looked for galaxies in its ∼ 1 pMpc^2 environment. We found one UV-bright Lyman-break galaxy candidate in addition to a [CII]-emitter associated with the quasar environment and clustered within a projected distance of ≲ 220 pkpc from the quasar. Future observations in the near-IR and mm would be necessary to confirm the redshift and physical properties of these galaxies and assess the number density of one of the earliest quasar large-scale environments yet explored. We also studied extensively the radio-loud quasar P352–15 at z = 5.832; the only source found thus far with evidence of a kpc-scale extended jet. Thus, this quasar is the ideal laboratory to investigate the first stages of black hole–jet–host galaxy co-evolution. We first studied the cold dust and [CII] gas of the host galaxy of P352–15 to explore whether the jet presence affects the host galaxy properties. The results on the inferred star formation rate and far-infrared luminosity were found to be comparable to studies on the radio-quiet quasar population. However, we found evidence of a spectral break in the jet synchrotron emission affecting the cold dust emission of the host galaxy. We further investigated the effect of the synchrotron spectral break by requesting additional Karl G. Jansky Very Large Array (VLA) radio observations. Using these new data, we found the frequency of the spectral break, we were able to calculate the jet age since its time of launch. We compared this jet timescale to the quasar lifetime, or the time since the last black hole accretion event. Both timescales were found to be comparatively young of just ≲ 10^4 yrs within their uncertainties, evidencing a fairly recent quasar activity of P352–15. The work in this thesis shows that studying different scales of quasar environments at z ≳ 6 is essential to understanding the formation and evolution of galaxies and black holes in the early universe
Propuesta de modelo de reducción de incompatibilidades en proyectos viales para dar continuidad de ejecución
El presente trabajo de investigación lleva por título “Propuesta de Modelo de
Reducción de Incompatibilidades en Proyectos Viales para dar continuidad de ejecución”,
tuvo como objetivo principal proponer un modelo de reducción de incompatibilidades en
proyectos de infraestructura vial con la finalidad de mantener la continuidad de ejecución
de obra, mediante un análisis documentario de expedientes técnicos. El problema surge
porque las empresas constructoras y las entidades públicas tienen problemas en ubicar a
tiempo las incompatibilidades con los planos de las diferentes especialidades. El enfoque
de la investigación fue cualitativo, tipo documental, nivel descriptivo y diseño no
experimental, de corte transversal; teniendo el método de investigación deductivo. El
universo de estudio estuvo constituido por todas las incompatibilidades de los expedientes
técnicos de las obras viales en el sector público. Finalmente, con la elaboración de los
flujogramas para reducir las incompatibilidades, la investigación determinó la
optimización de los costos pues se redujeron los tiempos de atrasos en obras mediante el
cumplimiento de metas, y la entidad no aumenta el monto del presupuesto inicial
Enhanced X-ray Emission from the Most Radio-Powerful Quasar in the Universe's First Billion Years
We present deep (265 ks) Chandra X-ray observations of PSO
J352.403415.3373, a quasar at z=5.831 that, with a radio-to-optical flux
ratio of R>1000, is one of the radio-loudest quasars in the early universe and
is the only quasar with observed extended radio jets of kpc-scale at . Modeling the X-ray spectrum of the quasar with a power law, we find a best
fit of , leading to an X-ray luminosity of
and
an X-ray to UV brightness ratio of . We
identify a diffuse structure 50 kpc () to the NW of the
quasar along the jet axis that corresponds to a enhancement in the
angular density of emission and can be ruled out as a background fluctuation
with a probability of P=0.9985. While with few detected photons the spectral
fit of the structure is uncertain, we find that it has a luminosity of
. These observations therefore
potentially represent the most distant quasar jet yet seen in X-rays. We find
no evidence for excess X-ray emission where the previously-reported radio jets
are seen (which have an overall linear extent of ), and a
bright X-ray point source located along the jet axis to the SE is revealed by
optical and NIR imaging to not be associated with the quasar.Comment: 16 pages, 7 Figures. Accepted for publication the Astrophysical
Journa
A primary healthcare information intervention for communicating cardiovascular risk to patients with poorly controlled hypertension: The Education and Coronary Risk Evaluation (Educore) study-A pragmatic, cluster-randomized trial
PURPOSE: Uncertainty exists regarding the best way to communicate cardiovascular risk (CVR) to patients, and it is unclear whether the comprehension and perception of CVR varies according to the format used. The aim of the present work was to determine whether a strategy designed for communicating CVR information to patients with poorly controlled high blood pressure (HBP), but with no background of cardiovascular disease, was more effective than usual care in the control of blood pressure (BP) over the course of a year. METHODS: A pragmatic, two-arm, cluster-randomized controlled trial was performed. Consecutive patients aged 40-65 years, all diagnosed with HBP in the last 12 months, and all of whom showed poor control of their condition (systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg), were recruited at 22 primary healthcare centres. Eleven centres were randomly assigned to the usual care arm, and 11 to the informative intervention arm (Educore arm). At the start of the study, the Educore arm subjects were shown the "low risk SCORE table", along with impacting images and information pamphlets encouraging the maintenance of good cardiovascular health. The main outcome variable measured was the control of HBP; the secondary outcome variables were SCORE table score, total plasma cholesterol concentration, use of tobacco, adherence to prescribed treatment, and quality of life. RESULTS: The study participants were 411 patients (185 in the Educore arm and 226 in the usual care arm). Multilevel logistic regression showed that, at 12 months, the Educore intervention achieved better control of HBP (OR = 1.57; 1.02 to 2.41). No statistically significant differences were seen between the two arms at 12 months with respect to the secondary outcomes. CONCLUSIONS: Compared to usual care, the Educore intervention was associated with better control of HBP after adjusting for age, baseline SBP and plasma cholesterol, at 12 months.This study was funded by the Spanish Ministry of Science and Innovation via the Instituto de Salud Carlos III, Subprograma de Proyectos de Investigación en Evaluación de Tecnologías Sanitarias y Servicios de Salud (PI 09/90354), and the Fundación de Investigación e Innovación Biomédica en Atención Primaria (FIIBAP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptS
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A SPectroscopic Survey of Biased Halos in the Reionization Era (ASPIRE): A First Look at the Rest-frame Optical Spectra of z > 6.5 Quasars Using JWST
© 2023. The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, see: https://creativecommons.org/licenses/by/4.0/Studies of rest-frame optical emission in quasars at z > 6 have historically been limited by the wavelengths accessible by ground-based telescopes. The James Webb Space Telescope (JWST) now offers the opportunity to probe this emission deep into the reionization epoch. We report the observations of eight quasars at z > 6.5 using the JWST/NIRCam Wide Field Slitless Spectroscopy as a part of the “A SPectroscopic survey of biased halos In the Reionization Era (ASPIRE)” program. Our JWST spectra cover the quasars’ emission between rest frame ∼4100 and 5100 Å. The profiles of these quasars’ broad Hβ emission lines span a full width at half maximum from 3000 to 6000 km s−1. The Hβ-based virial black hole (BH) masses, ranging from 0.6 to 2.1 billion solar masses, are generally consistent with their Mg ii-based BH masses. The new measurements based on the more reliable Hβ tracer thus confirm the existence of a billion solar-mass BHs in the reionization epoch. In the observed [O iii] λ λ 4960,5008 doublets of these luminous quasars, broad components are more common than narrow core components (≤ 1200 km s−1), and only one quasar shows stronger narrow components than broad. Two quasars exhibit significantly broad and blueshifted [O iii] emission, thought to trace galactic-scale outflows, with median velocities of −610 and −1430 km s−1 relative to the [C ii] 158 μm line. All eight quasars show strong optical Fe ii emission and follow the eigenvector 1 relations defined by low-redshift quasars. The entire ASPIRE program will eventually cover 25 quasars and provide a statistical sample for the studies of the BHs and quasar spectral properties.Peer reviewe
The Caldera. No. 15
“No existe gran talento sin gran voluntad”. Honoré de Balzac. Desde la inteligencia emocional se distinguen una serie de cualidades, de aptitudes y de características que diferencian a un ser humano de otro y que nos permiten hablar de los determinados talentos que cada uno de nosotros posee. En nuestra institución, precisamente, existe un nutrido número de niños y de jóvenes talentosos en diferentes campos, a saber: La música, el teatro, la danza, el canto, los deportes, la escritura, la pintura, el diseño y, por supuesto, a nivel académico; personas sensibles al arte y a sus diferentes manifestaciones porque poseen un talento intrínseco que les permite destacarse en el medio en donde interactúan. En esta edición de “La Caldera” se pretende continuar con la labor de seguir destacando, mostrando, promoviendo algunos de los talentosos estudiantes que hacen parte de nuestra Institución. La edición también tiene como meta hacer la invitación a aquellos talentos aprendidos o innatos, pero ocultos, para que compartan con nuestra familia caldista sus dones. Es así como la institución privilegia diferentes espacios institucionales que, años tras año, han ido consolidándose como la muestra de talentos caldistas, en donde conocemos, valoramos, apreciamos y disfrutamos, precisamente, de las destrezas, de las habilidades que tienen nuestros educandos. Hagamos parte activa de estos espacios porque en la medida en la que nos involucremos, en esa medida, nuestra Institución seguirá creciendo y destacándose como una de las mejores a nivel regional y nacional.Entrevista a: William Ospina; Por: Lina maría Beltrán…04
El infinito Océano de la paz; Por: María Camila Escobar y Nicolás Espinel Martínez…05
Homenaje a Gabriel García Márquez; Por: Gisela Afanador…10
Dibujando sueños; Por: Lina maría Beltrán…14
A través de los ojos de Camila; Por: Valentina Vega…16
Expresiones Artísticas…17"There is no great talent without great will." Honoré de Balzac. From emotional intelligence, a series of qualities, aptitudes and characteristics are distinguished that differentiate one human being from another and that allow us to talk about the specific talents that each of us possesses. In our institution, precisely, there is a large number of talented children and young people in different fields, namely: music, theater, dance, singing, sports, writing, painting, design and, of course , at the academic level; people who are sensitive to art and its different manifestations because they have an intrinsic talent that allows them to stand out in the environment where they interact. In this edition of "La Caldera" it is intended to continue with the work of continuing to stand out, showing, promoting some of the talented students that are part of our Institution. The edition also aims to invite those talents learned or innate, but hidden, to share their gifts with our Caldista family. This is how the institution privileges different institutional spaces that, year after year, have been consolidated as the sample of Caldista talents, where we know, value, appreciate and enjoy, precisely, the skills, the abilities that our students have. Let's take an active part in these spaces because to the extent that we get involved, to that extent, our Institution will continue to grow and stand out as one of the best at the regional and national level
Effectiveness of a strategy that uses educational games to implement clinical practice guidelines among Spanish residents of family and community medicine (e-EDUCAGUIA project):A clinical trial by clusters
This study was funded by the Fondo de Investigaciones Sanitarias FIS Grant Number PI11/0477 ISCIII.-REDISSEC Proyecto RD12/0001/0012 AND FEDER Funding.Background: Clinical practice guidelines (CPGs) have been developed with the aim of helping health professionals, patients, and caregivers make decisions about their health care, using the best available evidence. In many cases, incorporation of these recommendations into clinical practice also implies a need for changes in routine clinical practice. Using educational games as a strategy for implementing recommendations among health professionals has been demonstrated to be effective in some studies; however, evidence is still scarce. The primary objective of this study is to assess the effectiveness of a teaching strategy for the implementation of CPGs using educational games (e-learning EDUCAGUIA) to improve knowledge and skills related to clinical decision-making by residents in family medicine. The primary objective will be evaluated at 1 and 6months after the intervention. The secondary objectives are to identify barriers and facilitators for the use of guidelines by residents of family medicine and to describe the educational strategies used by Spanish teaching units of family and community medicine to encourage implementation of CPGs. Methods/design: We propose a multicenter clinical trial with randomized allocation by clusters of family and community medicine teaching units in Spain. The sample size will be 394 residents (197 in each group), with the teaching units as the randomization unit and the residents comprising the analysis unit. For the intervention, both groups will receive an initial 1-h session on clinical practice guideline use and the usual dissemination strategy by e-mail. The intervention group (e-learning EDUCAGUIA) strategy will consist of educational games with hypothetical clinical scenarios in a virtual environment. The primary outcome will be the score obtained by the residents on evaluation questionnaires for each clinical practice guideline. Other included variables will be the sociodemographic and training variables of the residents and the teaching unit characteristics. The statistical analysis will consist of a descriptive analysis of variables and a baseline comparison of both groups. For the primary outcome analysis, an average score comparison of hypothetical scenario questionnaires between the EDUCAGUIA intervention group and the control group will be performed at 1 and 6months post-intervention, using 95% confidence intervals. A linear multilevel regression will be used to adjust the model. Discussion: The identification of effective teaching strategies will facilitate the incorporation of available knowledge into clinical practice that could eventually improve patient outcomes. The inclusion of information technologies as teaching tools permits greater learning autonomy and allows deeper instructor participation in the monitoring and supervision of residents. The long-term impact of this strategy is unknown; however, because it is aimed at professionals undergoing training and it addresses prevalent health problems, a small effect can be of great relevance. Trial registration: ClinicalTrials.gov: NCT02210442.Publisher PDFPeer reviewe