Lithium in the Hyades L5 brown dwarf 2MASS J04183483+2131275

Aims. From the luminosity, effective temperature and age of the Hyades brown dwarf 2MASS J04183483+2131275 (2M0418), substellar evolutionary models predict a mass in the range 39−55 Jupiter masses (MJup) which is insufficient to produce any substantial lithium burning except for the very upper range >53 MJup. Our goal is to measure the abundance of lithium in this object, test the consistency between models and observations and refine constraints on the mass and age of the object. Methods. We used the 10.4-m Gran Telescopio Canarias (GTC) with its low-dispersion optical spectrograph to obtain ten spectra of 2277 s each covering the range 6300–10 300 Å with a resolving power of R ~ 500. Results. In the individual spectra, which span several months, we detect persistent unresolved Hα in emission with pseudo equivalent widths (pEW) in the range 45–150 Å and absorption lines of various alkalis with the typical strengths found in objects of L5 spectral type. The lithium resonance line at 6707.8 Å is detected with pEW of 18 ± 4 Å in 2M0418 (L5). Conclusions. We determine a lithium abundance of log N(Li) = 3.0 ± 0.4 dex consistent with a minimum preservation of 90% of this element which confirms 2M0418 as a brown dwarf with a maximum mass of 52 MJup. We infer a maximum age for the Hyades of 775 Myr from a comparison with the BHAC15 models. Combining recent results from the literature with our study, we constrain the mass of 2M0418 to 45–52 MJup and the age of the cluster to 580–775 Myr (1σ) based on the lithium depletion boundary method.We thank the referee for a detailed report that improved the quality of this manuscript. This research has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under the grants AYA2015- 69350-C3-2-P and AYA2015-69350-C3-3-P. We thank Yakiv Pavlenko for his calculations of equivalent widths at different temperatures, Isabelle Baraffe for her models, and Eduardo Martín for sharing his results prior to publication. This work is based on observations made with the Gran Telescopio Canarias (GTC), operated on the island of La Palma in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias (programme GTC77- 16B led by Pérez Garrido). This research has made use of the Simbad and Vizier databases, operated at the Centre de Données Astronomiques de Strasbourg (CDS), and of NASA’s Astrophysics Data System Bibliographic Services (ADS). We thank John Stauffer for kindly providing the optical spectra of the K and M Hyades members published in 1997 (Stauffer et al. 1997a)

Influence of the notch-sharpening technique on styrene-acrylonitrile fracture behavior

The Centre Catala del Plastic and Universidad Rey Juan Carlos laboratories joined forces to investigate the effect of the notch-sharpening technique on the fracture parameters of styrene-acrylonitrile. Contact notch-sharpening techniques, such as razor tapping, razor sliding, and razor broaching, and a noncontact procedure, femtolaser, were analyzed. The fracture values of the samples with notches sharpened via contact techniques were divided into two groups: one with pop-in and the other with no pop-in in the load-displacement records; this resulted in the lowest and highest fracture toughnesses, respectively. The fracture parameters of the specimens with notches sharpened via a femtolaser were between those of the samples with notches sharpened via contact procedures in which pop-in occurred and those in which it did not. To explain these results, the crack front of the nontested specimens after sharpening was investigated in depth, we identified the type of damage and measured its size and the crack tip radii. The morphology of the crack front was related to the fractographic study.Postprint (author's final draft

Enfermedad de Chagas en Nicaragua

LA ENFERMEDAD DE CHAGAS ES UN PROBLEMA DE SALUD pública en toda Latinoamérica; alrededor de 20 millones de personas están infectadas y 200 millones están en riesgo de contraer la enfermedad. En 2006, la prevalencia en Centroamérica era del 7%. Actualmente no existe vacuna contra el protozoo y el tratamiento disponible resulta, aparte de poco efectivo, muy tóxico para el paciente. Los programas de control de vectores han ayudado a reducir los índices de infestación en Latinoamérica, pero aún falta mucho por hacer. En Nicaragua, la enfermedad de Chagas está subvalorada y los trabajos publicados son muy pocos. Es necesario investigar sobre esta enfermedad en nuestro país con otro enfoque, uno que no subvalore la enfermedad y ayude a desarrollar métodos diagnósticos y posibles tratamientos. Este artículo recopila información sobre los trabajos realizados porlos grupos más importantes de investigación en Chagas de Nicaragua en cuanto a epidemiología, control vectorial, diagnóstico y caracterización molecular

METHONTOLOGY: From Ontological Art Towards Ontological Engineering

This paper does not pretend either to transform completely the ontological art in engineering or to enumerate exhaustively the complete set of works that has been reported in this area. Its goal is to clarify to readers interested in building ontologies from scratch, the activities they should perform and in which order, as well as the set of techniques to be used in each phase of the methodology. This paper only presents a set of activities that conform the ontology developmentp rocess, a life cycle to build ontologies based in evolving prototypes, and METHONTOLOGY, a well-structured methodology used to build ontologies from scratch. This paper gathers the experience of the authors on building an ontology in the domain of chemicals

Evaluation of CNN architectures for gait recognition based on optical flow maps

This work targets people identification in video based on the way they walk (\ie gait) by using deep learning architectures. We explore the use of convolutional neural networks (CNN) for learning high-level descriptors from low-level motion features (\ie optical flow components). The low number of training samples for each subject and the use of a test set containing subjects different from the training ones makes the search of a good CNN architecture a challenging task.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

The role of the humanisation of smart home speakers in the personalisation–privacy paradox

This article examines the personalisation–privacy paradox through the privacy calculus lens in the context of smart home speakers. It also considers the direct and moderating role of humanisation in the personalisation–privacy paradox. This characteristic refers to how human the device is perceived to be, given its voice''s tone and pacing, original responses, sense of humour, and recommendations. The model was tested on a sample of 360 users of different brands of smart home speakers. These users were heterogeneous in terms of age, gender, income, and frequency of use of the device. The results confirm the personalisation–privacy paradox and verify uncanny valley theory, finding the U-shaped effect that humanisation has on risks of information disclosure. They also show that humanisation increases benefits, which supports the realism maximisation theory. Specifically, they reveal that users will perceive the messages received as more useful and credible if the devices seem human. However, the human-likeness of these devices should not exceed certain levels as it increases perceived risk. These results should be used to highlight the importance of the human-like communication of smart home speakers. © 2022 The Author

Power conversion efficiency of non-equilibrium light absorption

We deduce a novel expression for the non-equilibrium photochemical potential and the power conversion efficiency of non-equilibrium light absorption by a thermostated material. Application of our results for the case of electron migration from valence to conduction bands in photovoltaic cells allows us to accurately interpolate experimental results for the maximal efficiencies of Ge-, Si-, GaAsbased cells and the like

Local Anomalies, Local Equivariant Cohomology and the Variational Bicomplex

The locality conditions for the vanishing of local anomalies in field theory are shown to admit a geometrical interpretation in terms of local equivariant cohomology, thus providing a method to deal with the problem of locality in the geometrical approaches to the study of local anomalies based on the Atiyah-Singer index theorem. The local cohomology is shown to be related to the cohomology of jet bundles by means of the variational bicomplex theory. Using these results and the techniques for the computation of the cohomology of invariant variational bicomplexes in terms of relative Gel'fand-Fuks cohomology introduced in [6], we obtain necessary and sufficient conditions for the cancellation of local gravitational and mixed anomalies.Comment: 36 pages. The paper is divided in two part

Duración de sueño en personas mayores con síndrome metabólico

Sleep is a quality-of-life indicator. Sleep alterations have health consequences. The objective of the study was to analyze the sleep pattern in elderly people with metabolic syndrome. A cross-sectional study was carried out on a sample of 326 participants of node 01 of the PREDIMEDPLUS study (University of Malaga). The hours of sleep were quantified objectively with an accelerometer, and subjectively, with a self-reported questionnaire. The average duration of sleep (hours) measured with the accelerometer was higher in women (6.6±0.1) than in men (6.2±0.1); these data differ from self-reported data of 6.7h±0.1 hours in men and 7.3h±0.1 in women. 43% of men and 30% of women sleep less than 6 hours. A high percentage of participants have a poor sleep. In addition, future methodological investigations of sleep assessment are needed.El sueño es un indicador de la calidad de vida. Sus alteraciones pueden afectar la salud. El objetivo del estudio fue analizar el patrón de sueño en personas mayores con síndrome metabólico. Se realizó un estudio transversal en 326 participantes del nodo 01 del Estudio PREDIMEDPLUS (Universidad de Málaga). Las horas de sueño se cuantificaron de forma objetiva con un acelerómetro, y de manera subjetiva, a partir de un cuestionario. La duración media del sueño (horas) medida con el acelerómetro fue mayor en mujeres (6,6 ± 0,1) que en hombres (6,2 ± 0,1); estos datos difieren de los auto-declarados de 6,7 ± 0,1 horas en hombres y 7,3 ± 0,1 en mujeres. Un 43 % de hombres y un 30 % de mujeres duermen menos de 6 horas. Un alto porcentaje de los participantes tienen un sueño deficiente. Además, se necesitan futuras investigaciones metodológicas de la evaluación del sueño

In situ surface coverage analysis of RuO₂-catalysed HCl oxidation reveals the entropic origin of compensation in heterogeneous catalysis

In heterogeneous catalysis, rates with Arrhenius-like temperature dependence are ubiquitous. Compensation phenomena, which arise from the linear correlation between the apparent activation energy and the logarithm of the apparent pre-exponential factor, are also common. Here, we study the origin of compensation and find a similar dependence on the rate-limiting surface coverage term for each Arrhenius parameter. This result is derived from an experimental determination of the surface coverage of oxygen and chlorine species using temporal analysis of products and prompt gamma activation analysis during HCl oxidation to Cl2 on a RuO2 catalyst. It is also substantiated by theory. We find that compensation phenomena appear when the effect on the apparent activation energy caused by changes in surface coverage is balanced out by the entropic configuration contributions of the surface. This result sets a new paradigm in understanding the interplay of compensation effects with the kinetics of heterogeneously catalysed processes