Double-Peaked Broad Emission Lines in NGC 4450 and Other LINERs

Spectra taken with HST reveal that NGC 4450 emits Balmer emission lines with displaced double peaks and extremely high-velocity wings. This characteristic line profile, previously seen in a few nearby LINERs and in a small fraction of broad-line radio galaxies, can be interpreted as a kinematic signature of a relativistic accretion disk. We can reproduce the observed profile with a model for a disk with a radial range of 1000-2000 gravitational radii and inclined by 27 degrees along the line of sight. The small-aperture HST data also allow us to detect, for the first time, the featureless continuum at optical wavelengths in NGC 4450; the nonstellar nucleus is intrinsically very faint, with M_B = -11.2 mag for D = 16.8 Mpc. We have examined the multiwavelength properties of NGC 4450 collectively with those of other low-luminosity active nuclei which possess double-peaked broad lines and find a number of common features. These objects are all classified spectroscopically as "type 1" LINERs or closely related objects. The nuclear luminosities are low, both in absolute terms and relative to the Eddington rates. All of them have compact radio cores, whose strength relative to the optical nuclear emission places them in the league of radio-loud active nuclei. The broad-band spectral energy distributions of these sources are most notable for their deficit of ultraviolet emission compared to those observed in luminous Seyfert 1 nuclei and quasars. The double-peaked broad-line radio galaxies Arp 102B and Pictor A have very similar attributes. We discuss how these characteristics can be understood in the context of advection-dominated accretion onto massive black holes.Comment: To appear in The Astrophysical Journal. Latex, 15 pages, embedded figures and tabl

Is the Broad-Line Region Clumped or Smooth? Constraints from the H alpha Profile in NGC 4395, the Least Luminous Seyfert 1 Galaxy

The origin and configuration of the gas which emits broad lines in Type I active galactic nuclei is not established yet. The lack of small-scale structure in the broad emission-line profiles is consistent with a smooth gas flow, or a clumped flow with many small clouds. An attractive possibility for the origin of many small clouds is the atmospheres of bloated stars, an origin which also provides a natural mechanism for the cloud confinement. Earlier studies of the broad-line profiles have already put strong lower limits on the minimum number of such stars, but these limits are sensitive to the assumed width of the lines produced by each cloud. Here we revisit this problem using high-resolution Keck spectra of the H alpha line in NGC 4395, which has the smallest known broad-line region (~10^14 cm). Only a handful of the required bloated stars (each having r~10^14 cm) could fit into the broad-line region of NGC 4395, yet the observed smoothness of the H alpha line implies a lower limit of ~10^4-10^5 on the number of discrete clouds. This rules out conclusively the bloated-stars scenario, regardless of any plausible line-broadening mechanisms. The upper limit on the size of the clouds is ~10^12 cm, which is comparable to the size implied by photoionization models. This strongly suggests that gas in the broad-line region is structured as a smooth rather than a clumped flow, most likely in a rotationally dominated thick disk-like configuration. However, it remains to be clarified why such a smooth, gravity-dominated flow generates double-peaked emission lines only in a small fraction of active galactic nuclei.Comment: 12 pages, including 3 figures, accepted for publication in The Astrophysical Journa

Jobless and burnt out: digital inequality and online access to the labor market

This article examines how inequalities in digital skills shape the outcomes of online job‐seeking processes. Building on a representative survey of Spanish job seekers, we show that people with high digital skill levels have a greater probability of securing a job online, because of their ability to create a coherent profile and make their application visible. Additionally, it is less probable that they will experience burnout during this process than job seekers with low digital skill levels. Given the concentration of digital skills amongst people with high levels of material and digital resources, we conclude that the internet enforces existing material and health inequalities

Influencia de las competencias gerenciales y la gestión por resultados en la imagen institucional

La investigación buscó determinar si existe influencia entre las competencias gerenciales y la gestión por resultados en la imagen institucional de la Unidad de Gestión Educativa Local 02 en Lima Perú, estudio que se realizó entre septiembre del 2017 y mayo del 2018; investigación orientada en el paradigma positivista de enfoque cuantitativo y de diseño correlacional causal. Se concluye que si existe influencia de las variables competencias gerenciales y gestión por resultados en la imagen institucional por lo que se sugiere se considere al personal docente estudiado sujetos activos de la imagen institucional de dicha institución

Coronary Obstruction Following Transcatheter Aortic Valve Implantation for Degenerative Bioprosthetic Surgical Valves: a Systematic Literature Review

ABSTRACTBackgroundVery few data exist on coronary obstruction following transcatheter aortic valve implantation (TAVI) for degenerative bioprosthetic valves (valve-in-valve [ViV]). The present trial evaluated, through a systematic review of the literature, the clinical characteristics, management and clinical outcomes of patients with coronary obstruction after ViV-TAVI.MethodsStudies published between 2002 and 2013 evaluating coronary obstruction as a complication of ViV-TAVI were identified using a systematic electronic search. Data on the clinical and procedural characteristics, management of the complication, and clinical outcomes were analyzed.ResultsA total of four publications describing seven patients were identified. Most patients (71%) were women, with mean age of 82±5 years, and STS-PROM score of 9.4±2.6%. Mean left coronary artery (LCA) ostium height and aortic root width were 8.8±1.5mm and 28.0±5.0mm, respectively. Most patients had stented bioprosthetic valves with externally mounted leaflets or stentless aortic bioprosthesis, and the LCA was involved in all patients. Percutaneous coronary intervention (PCI) was attempted in all patients and was successful in four (57%). In-hospital mortality was 42.9% (three cases), all of them after failed PCI.ConclusionsCoronary obstruction following ViV-TAVI occurred more frequently in women with stented bioprosthetic valves with externally mounted leaflets or with stentless bioprosthesis. The LCA was involved in all cases and PCI was successful in 60% of them. Continued efforts may help identify the factors associated with this complication so that appropriate prevention measures may be implemented

Didactic strategies in the development of critical thinking in secondary school students

Objetivo. Evaluar las estrategias didácticas usadas en las sesiones de aprendizaje del área de comunicación para desarrollar el pensamiento crítico en estudiantes de educación secundaria de instituciones educativas de la jurisdicción de Ocros. El desarrollo del aprendizaje en el siglo XXI exige que sus estudiantes desarrollen altos niveles de pensamiento y creatividad, utilizando diversas estrategias pedagógicas por parte de la comunidad docente. Metodología. Se utilizaron los diseños cuantitativo y cualitativo, por lo tanto, este estudio se caracteriza por ser de naturaleza mixta; triangulándose no solo datos, eventos y entrevistas aisladas, sino también el análisis y la reflexión pedagógica. Se utilizaron los diseños cuantitativo y cualitativo, los cuales permiten analizar e inferir cómo los docentes de la provincia de Ocros-Huaraz-Perú desarrollan la gestión del aula. Resultados y conclusión. El pensamiento crítico, en sus tres subcategorías: razonamiento, argumentación y toma de decisiones, permite afirmar que los docentes presentan fuertes debilidades en su proceso de conducción de los aprendizajes y los estudiantes carecen de herramientas cognitivas que posibiliten realizar una lectura crítica.Objective: To evaluate the didactic strategies used in the learning sessions of the communication area to develop critical thinking in secondary school students of educational institutions in the jurisdiction of Ocros. The development of learning in the 21st century requires that students develop high levels of thought and creativity, using various pedagogical strategies by the teaching community. Methodology: Quantitative and qualitative designs were used so this study is characterized as being of a mixed nature, triangulating not only data, events and interviews, but also the pedagogical analysis and reflection. Quantitative and qualitative designs were used which allow analyzing and inferring how teachers in the province of Ocros-Huaraz-Peru develop classroom management. Results and conclusion: Critical thinking, in its three subcategories, reasoning, argumentation and decision-making, allows affirming that teachers have strong weaknesses in their process of conducting learning, and students lack cognitive tools that make it possible to carry out critical reading

Realización profesional en docentes de Lima Este en un contexto de emergencia sanitaria COVID-19

El objetivo general de la presente investigación fue determinar las diferencias que existen en los factores que describen la realización profesional en los docentes de educación primaria en instituciones educativas de Lima Este en un contexto de enseñanza no presencial por la emergencia sanitaria COVID-19. La investigación fue de enfoque cuantitativo, tipo descriptivo, diseño no experimental, nivel comparativo, de corte transversal; la población constituida por los docentes quienes son los principales protagonistas; la muestra de 384 y el muestreo probabilístico; siendo el instrumento un cuestionario elaborado en Formulario Google. Los resultados indicaron que se evidencia que en los niveles de satisfacción en los factores que comprende la realización profesional existen diferencias significativas estadísticamente; es decir, la realización personal y la realización en el centro de trabajo, difieren, si se les compara en los niveles alcanzados; siendo que la realización en el centro de trabajo presentó mejor situación en cuanto a la satisfacción

Impact of Low Flow on the Outcome of High-Risk Patients Undergoing Transcatheter Aortic Valve Replacement

ObjectivesThis study sought to assess the impact of baseline left ventricular (LV) outflow, LV ejection fraction (LVEF), and transvalvular gradient on outcomes following transcatheter aortic valve replacement (TAVR) in patients with severe aortic stenosis (AS).BackgroundLow flow (i.e., reduced stroke volume index [SVi]) can occur with both reduced and preserved LVEF. Low flow is often associated with low gradient despite severe stenosis and with worse outcomes following surgical aortic valve replacement. However, there are few data about the impact of low flow on outcomes following TAVR.MethodsWe retrospectively analyzed the clinical, Doppler-echocardiographic, and outcome data prospectively collected in 639 patients who underwent TAVR for symptomatic severe AS in 2 Canadian centers.ResultsIn this cohort, 334 (52.3%) patients had a low flow (SVi <35 ml/m2) and these patients had increased 30-day mortality (11.4 vs. 5.9%, p = 0.01), 2-year all-cause mortality (35.3 vs. 30.9%, p = 0.005), and 2-year cardiovascular mortality (25.7 vs. 16.8%, p = 0.01) compared with patients with normal flow. Reduced flow was an independent predictor of 30-day mortality (odds ratio: 1.94, p = 0.026), cumulative all-cause mortality (hazard ratio: 1.27 per 10 ml/m² SVi decrease, p = 0.016), and cumulative cardiovascular mortality (hazard ratio: 1.29 per 10 ml/m² decrease, p = 0.04). Despite significant association in univariable analyses, low LVEF and low mean gradient were not found to be independent predictors of outcomes in multivariable analyses.ConclusionsLow flow but not low LVEF or low gradient is an independent predictor of early and late mortality following TAVR in high-risk patients with severe AS. SVi should be integrated in the risk stratification process of these patients

Incidence, predictive factors and haemodynamic consequences of acute stent recoil following transcatheter aortic valve implantation with a balloon-expandable valve

Aims: The elastic behaviour (acute recoil) of a valve prosthesis stent following transcatheter aortic valve implantation (TAVI) is unknown. This study sought to determine the occurrence, severity, predictive factors and haemodynamic consequences of acute recoil following TAVI. Methods and results : A prospective angiographic analysis of the stent frame dimensions in 111 consecutive patients who underwent TAVI with a balloon-expandable valve (36 Edwards SAPIEN; 75 SAPIEN XT) was performed. Acute recoil was defined as the difference between minimal lumen diameter (MLD) at full balloon expansion and immediately after balloon deflation. MLD during balloon inflation was significantly larger than MLD after balloon deflation (23.40±2.31 mm vs. 22.29±2.21 mm, p<0.001), which represented an absolute and percent decrease in stent dimension of 1.10±0.40 mm and 4.70±1.76%, respectively. In the multivariate analysis, the predictors of larger recoil were a higher prosthesis/annulus ratio (r²=0.0624, p=0.015) and the SAPIEN XT prosthesis (r²=0.1276, p=0.001). No significant changes in haemodynamic performance were observed at discharge and follow-up in patients with larger recoil. Conclusions : TAVI with a balloon-expandable valve was systematically associated with a certain degree of valve stent recoil after balloon deflation. A higher degree of valve oversizing and the SAPIEN XT prosthesis predicted a larger degree of stent recoil