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)

Non-ergodic effects in the Coulomb glass: specific heat

We present a numerical method for the investigation of non-ergodic effects in the Coulomb glass. For that, an almost complete set of low-energy many-particle states is obtained by a new algorithm. The dynamics of the sample is mapped to the graph formed by the relevant transitions between these states, that means by transitions with rates larger than the inverse of the duration of the measurement. The formation of isolated clusters in the graph indicates non-ergodicity. We analyze the connectivity of this graph in dependence on temperature, duration of measurement, degree of disorder, and dimensionality, studying how non-ergodicity is reflected in the specific heat.Comment: Submited Phys. Rev.

Dielectric susceptibility of the Coulomb-glass

We derive a microscopic expression for the dielectric susceptibility $\chi$ of a Coulomb glass, which corresponds to the definition used in classical electrodynamics, the derivative of the polarization with respect to the electric field. The fluctuation-dissipation theorem tells us that $\chi$ is a function of the thermal fluctuations of the dipole moment of the system. We calculate $\chi$ numerically for three-dimensional Coulomb glasses as a function of temperature and frequency

Young nearby open clusters and their luminosity functions

Context. Open clusters are groups of coeval stars sharing properties such as distance and metallicity, and they are key to understanding stellar evolution. Aims. Our main goal is to study the evolution of open clusters with a special focus on the universality of the luminosity function. Methods. We applied an upgraded version of the convergent point technique on about 50 open clusters. The selection of cluster members was based purely on the exquisite astrometry of the Gaia DR3 and Hipparcos catalogues in the five-dimensional or full six-dimensional space. Results. We present updated lists of bona fide members of ~50 open clusters within 500 pc and younger than 1 Gyr, exploiting the full depth of the third Gaia data release complemented by Hipparcos at the bright end, excluding regions in the Galactic plane. Our catalogues also are complemented by optical and infrared photometry from the major large-scale public surveys. All the data will be made available on a dedicated webpage with interactive plots and a direct link to Aladin and Vizier hosted at the Centre de Donn\'ees de Strasbourg. We derived luminosity functions for all bound clusters and compared them in three age groups of ~50 Myr, ~150 Myr, and ~600 Myr, discussing similarities and differences to constrain their dynamical evolution. Conclusions. Luminosity functions of clusters at 50 Myr are more likely similar to each other and show a greater degree of similarity than older clusters. We explain this observation with the universal luminosity function within the volume of our sample (500 pc). Luminosity functions of clusters with ages similar to the Pleiades or Hyades are more diverse, perhaps due to internal dynamical evolution, but more work is needed to provide additional evidence.Comment: 29 pages, 9 figures, accepted for publication in Astronomy & Astrophysic

Editors’ introduction: connectivity and diversity in music cognition

Scholarly interest in the context of music listening and its influence on music cognition and connection is flourishing after decades of a predominantly individualistic approach. This article introduces a special issue that explores research on the theme of connectivity and diversity in music cognition research arising from the ICMPC16-ESCOM11 conference. The conference itself, held online during the later stages of the COVID-19 pandemic in 2021, transcended national borders, bringing together researchers and practitioners from multiple continents in a digital context. In this introduction, we set the scene for this topic as it related to the conference. The included papers are the outcome of workshops held as part of the conference. The first paper in the special issue explores the use of embodied consciousness as part of pedagogical strategies to help music performers connect with embodied memories that can support their understanding of the work they are performing. The second paper considers uses of music in the early stages of motherhood, including a comparison between the active choice to regularly sing or listen to music and its perceived effects for the mother and her infant. The papers and associated commentaries offer a window into the rich research theme of connectivity and diversity that is likely to be influential over the years to come

Relationships between dry land strength, power variables and short sprint performance in young competitive swimmers

The aim of this study was to identify the dry land strength and power tests that can better relate with sprint swimming performance in young competitive swimmers. Twenty-eight (16 boys and 12 girls) young competitive swimmers of national level (12.01 ± 0.56 years-old, Tanner stage 1-2) volunteered to participate in this study. Swimming performance (25 m and 50 m freestyle sprint tests), muscle strength (bench press and leg extension) and muscle power (throwing medicine ball and countermovement jump) performances were tested. Spearman ranking correlation coefficient were computed to verify the association between strength and power variables with sprint swimming performance. Regarding strength tests, the bench press and leg extension exercises were moderate but significantly associated with 25 m and 50 m tests (-0.69 ≤ ρ ≤ -0.58). The sprint tests were only associated with throwing power tests (-0.74 ≤ ρ ≤ -0.54) and not with vertical jump height. The main results suggested that, simple dry land strength and power tests although moderate are significantly associated with sprint swimming performance in young competitive swimmers

IDE ‑OTALEX C: A Primeira Infraestrutura de Dados Espaciais transfronteiriça entre Portugal e Espanha

Em 2007 criou ‑se a primeira Infraestrutura de Dados Espaciais transfronteiriça entre Portugal e Espanha (IDE ‑OTALEX – www.ideotalex.eu), que constituiu o Observatório Territorial e Ambiental Alentejo e Extremadura, ao qual se incorporou, em 2011, a região Centro de Portugal, que no total abrange uma superfície de 92.500 km2. Assim, surgiu o Observatório Territorial Alentejo ‑Extremadura ‑Centro (OTALEX C), possibilitando a integração da informação produzida pelas diversas instituições que desenvolvem as suas competências de planeamento e gestão territorial, nestas três regiões. Tendo como objetivo a monitorização e análise de alterações decorrentes de fenómenos naturais e da atividade humana sobre o território, bem como a disponibilização de dados e indicadores aos agentes que atuam neste território, foi desenvolvido um sistema de indicadores comuns, distribuídos por cinco vetores (territorial, ambiental, social, económico e de sustentabilidade). Os dados sofreram trabalhos de homogeneização e estandardização antes de serem integrados tendo em vista facilitar a visualização de mapas, consulta de topónimos e de catálogo, no âmbito da Diretiva INSPIRE. A IDE ‑OTALEX C é o resultado do esforço, do compromisso e da colaboração entre instituições da fronteira, com implicação aos três níveis administrativos: Nacional, Regional e Local. Concede uma visão sobre a situação real do território, ao mesmo tempo que faculta instrumentos adequados para as políticas de ação, que contribuem para apoiar o planeamento e ordenamento do território, a fim de alcançar um desenvolvimento sustentável.info:eu-repo/semantics/acceptedVersio

Mutations in the mitochondrial complex I assembly factor NDUFAF6 cause isolated bilateral striatal necrosis and progressive dystonia in childhood

Aim: To perform a deep phenotype characterisation in a pedigree of 3 siblings with Leigh syndrome and compound heterozygous NDUFAF6 mutations. Method: A multi-gene panel of childhood-onset basal ganglia neurodegeneration inherited conditions was analysed followed by functional studies in fibroblasts. Results: Three siblings developed gait dystonia in infancy followed by rapid progression to generalised dystonia and psychomotor regression. Brain magnetic resonance showed symmetric and bilateral cytotoxic lesions in the putamen and proliferation of the lenticular-striate arteries, latter spreading to the caudate and progressing to cavitation and volume loss. We identified a frameshift novel change (c.554_558delTTCTT; p.Tyr187AsnfsTer65) and a pathogenic missense change (c.371T>C; p.Ile124Thr) in the NDUFAF6 gene, which segregated with an autosomal recessive inheritance within the family. Patient mutations were associated with the absence of the NDUFAF6 protein and reduced activity and assembly of mature complex I in fibroblasts. By functional complementation assay, the mutant phenotype was rescued by the canonical version of the NDUFAF6. A literature review of 14 NDUFAF6 patients showed a consistent phenotype of an early childhood insidious onset neurological regression with prominent dystonia associated with basal ganglia degeneration and long survival. Interpretation: NDUFAF6-related Leigh syndrome is a relevant cause of childhood onset dystonia and isolated bilateral striatal necrosis. By genetic complementation, we could demonstrate the pathogenicity of novel genetic variants in NDUFAF6

Depressive symptoms in a sample of women with subclinical hypothyroidism and their relationship to chlorates in tap water

[ES] en el hipotiroidismo subclínico pueden aparecer síntomas depresivos y su presencia suele facilitar la instauración de un tratamiento de reemplazo; sin embargo, estudios recientes no han encontrado una asociación entre ambos. Por otra parte, la función tiroidea puede verse afectada por disruptores endocrinos y, algunos de ellos, como los cloratos, pueden encontrarse en el agua que bebemos. Objetivos: conocer si el tipo de consumo de agua puede influir en la aparición de síntomas depresivos en pacientes con hipotiroidismo subclínico. Métodos: participaron 96 mujeres con hipotiroidismo subclínico, sin tratamiento tiroideo, de un área de salud de España. Estudiamos, entre otras variables, la presencia de síntomas depresivos, el tipo de consumo de agua (grifo/embotellada o manantial) y el nivel de cloratos en el agua del grifo. Resultados: el 41,7 % (40) de las mujeres presentaban síntomas depresivos y estos se relacionaban con el consumo de agua del grifo (p = 0,001), resultando este un predictor confiable (OR: 27,79; p = 0,007). El nivel de cloratos en el agua del grifo era de 250 µg/L, valor situado en el límite máximo permitido por la ley. Conclusiones: en mujeres con hipotiroidismo subclínico, la exposición crónica a cloratos en el agua, en niveles autorizados por la ley, podría favorecer la inhibición del transporte de yodo y la aparición de síntomas depresivos. Sería interesante comprobar esta hipótesis, así como su posible efecto sobre otros perfiles poblacionales.S