24 research outputs found

    A search for evidence of irradiation in Centaurus X-4 during quiescence

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    We present a study of the neutron star X-Ray Transient Cen X-4. Our aim is to look for any evidence of irradiation of the companion with a detailed analysis of its radial velocity curve, relative contribution of the donor star and Doppler tomography of the main emission lines. To improve our study all our data are compared with a set of simulations that consider different physical parameters of the system, like the disc aperture angle and the mass ratio. We conclude that neither the radial velocity curve nor the orbital variation of the relative donor's contribution to the total flux are affected by irradiation. On the other hand, we do see emission from the donor star at Hα{\alpha} and HeI 5876 which we tentatively attribute to irradiation effects. In particular, the Hα{\alpha} emission from the companion is clearly asymmetric and we suggest is produced by irradiation from the hot-spot. Finally, from the velocity of the HeI 5876 spot we constrain the disc opening angle to alpha=7-14 deg.Comment: 4 pages, 5 figures, accepted for publication in A&A as a R

    La Presencia Salesiana en Ecuador: Perspectivas históricas y sociales

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    Este libro recoge los resultados de un programa de investigación sobre las siguientes dimensiones de la presencia salesiana en el país: desarrollo comunitario, inclusión social, niñez y adolescencia; educación salesiana, con énfasis en la educación técnica; conformación de identidades e interculturalidad. Esta investigación fue realizada por un equipo de la Universidad Politécnica Salesiana en convenio con la Sociedad Salesiana en el Ecuador. Participaron profesionales que aportaron sus propias visiones desde diversas ciencias sociales (historia, sociología y antropología) y de la educación. Por lo tanto, se trata de una obra interdisciplinaria que busca profundizar el diálogo entre la herencia espiritual-pedagógica salesiana, la ciencia y las expectativas de los pueblos y culturas de hoy en momento de complejidad creciente de la sociedad ecuatoriana sujeta a transformaciones radicales cargadas de desafíos para la comunidad salesiana y la misma Iglesia

    AgBioData consortium recommendations for sustainable genomics and genetics databases for agriculture

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    The future of agricultural research depends on data. The sheer volume of agricultural biological data being produced today makes excellent data management essential. Governmental agencies, publishers and science funders require data management plans for publicly funded research. Furthermore, the value of data increases exponentially when they are properly stored, described, integrated and shared, so that they can be easily utilized in future analyses. AgBioData (https://www.agbiodata.org) is a consortium of people working at agricultural biological databases, data archives and knowledgbases who strive to identify common issues in database development, curation and management, with the goal of creating database products that are more Findable, Accessible, Interoperable and Reusable. We strive to promote authentic, detailed, accurate and explicit communication between all parties involved in scientific data. As a step toward this goal, we present the current state of biocuration, ontologies, metadata and persistence, database platforms, programmatic (machine) access to data, communication and sustainability with regard to data curation. Each section describes challenges and opportunities for these topics, along with recommendations and best practices

    The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2,MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA,the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions ofthe SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE.This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV.PostprintPeer reviewe

    Refined physical parameters for Chariklo’s body and rings from stellar occultations observed between 2013 and 2020

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    Context. The Centaur (10199) Chariklo has the first ring system discovered around a small object. It was first observed using stellar occultation in 2013. Stellar occultations allow sizes and shapes to be determined with kilometre accuracy, and provide the characteristics of the occulting object and its vicinity. Aims. Using stellar occultations observed between 2017 and 2020, our aim is to constrain the physical parameters of Chariklo and its rings. We also determine the structure of the rings, and obtain precise astrometrical positions of Chariklo. Methods. We predicted and organised several observational campaigns of stellar occultations by Chariklo. Occultation light curves were measured from the datasets, from which ingress and egress times, and the ring widths and opacity values were obtained. These measurements, combined with results from previous works, allow us to obtain significant constraints on Chariklo's shape and ring structure. Results. We characterise Chariklo's ring system (C1R and C2R), and obtain radii and pole orientations that are consistent with, but more accurate than, results from previous occultations. We confirm the detection of W-shaped structures within C1R and an evident variation in radial width. The observed width ranges between 4.8 and 9.1 km with a mean value of 6.5 km. One dual observation (visible and red) does not reveal any differences in the C1R opacity profiles, indicating a ring particle size larger than a few microns. The C1R ring eccentricity is found to be smaller than 0.022 (3σ), and its width variations may indicate an eccentricity higher than ~0.005. We fit a tri-axial shape to Chariklo's detections over 11 occultations, and determine that Chariklo is consistent with an ellipsoid with semi-axes of 143.8-1.5+1.4, 135.2-2.8+1.4, and 99.1-2.7+5.4 km. Ultimately, we provided seven astrometric positions at a milliarcsecond accuracy level, based on Gaia EDR3, and use it to improve Chariklo's ephemeris

    The effects of exercise variation in muscle thickness, maximal strength and motivation in resistance trained men.

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    BACKGROUND:The objective of the present study was to compare the effects of a traditional resistance training program (fixed exercises and repetition ranges) to a resistance training program where exercises and repetition ranges were randomized on a session-by-session basis on markers of muscular adaptations and intrinsic motivation. METHODS:Twenty-one resistance trained men were randomized to perform an 8-week resistance training program using either a fixed exercise selection (CON) or having exercises randomly varied each session via a computerized app. Both groups performed 3 sets of 6 exercises, with training carried out 4 times per week. RESULTS:Both conditions promoted large, statistically significant increases in the bench press and back-squat 1 repetition maximum without differences between groups. Muscle thickness (MT) measures for the individual quadriceps showed large, statistically significant increases in of the vastus lateralis and rectus femoris for both conditions, with no observed between-group differences. Although no between-group in MT were noted for the vastus intermedius, only the CON displayed significant increases from baseline. Participants in EXP showed a significant, moderate improvement in the intrinsic motivation to training, while participants in the CON group presented non-significant decreases in this variable. CONCLUSIONS:Varying exercise selection had a positive effect on enhancing motivation to train in resistance-trained men, while eliciting similar improvements in muscular adaptations

    Análisis exploratorio de la asignatura Trabajo Fin de Grado en las universidades españolas

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    Introducción y objetivo El Trabajo Fin de Grado (TFG) es una asignatura obligatoria en el grado de Fisioterapia. El objetivo de este trabajo fue realizar un análisis exploratorio de la asignatura TFG en la universidad española transcurridos 12 años desde su implantación. Material y métodos Estudio descriptivo transversal mediante búsqueda estructurada en la página web de universidades españolas públicas y privadas que ofertan el título de Graduado en Fisioterapia. Las variables estudiadas fueron: número de créditos, temporalización, tipo de trabajo, guía docente, idioma, distribución de horas, perfil del tutor, criterios de evaluación, formato de defensa. Resultados Se analizaron 57 grados en 53 universidades. El número de créditos más frecuente fue 6. La distribución de horas observada: horas presenciales (17,5 ± 19,5); horas de trabajo supervisado (18,8 ± 21,3); horas de trabajo autónomo (144,4 ± 46,9). El diseño metodológico utilizado con más frecuencia fue la revisión bibliográfica (n = 24). En los criterios de evaluación, la calificación del tutor osciló entre el 0 y el 90% de la calificación final (41,7 ± 23,7) frente al 10-100% de la de los Tribunales (58,1 ± 24,4). Solo 21 grados informan del perfil del profesorado tutor. Conclusiones La asignación de créditos, las metodologías y los sistemas de evaluación son muy heterogéneos entre las universidades españolas en la asignatura de TFG del grado de Fisioterapia. Transcurridos 15 años desde que su incorporación a la titulación es necesario establecer un consenso para racionalizar la asignatura
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