4,937 research outputs found
Mass loss from an extreme OH/IR star: OH 26.5+0.6
Observations of H_{2}O isotopologues of the extreme OH/IR star OH 26.5+0.6 show
that the star has an initial mass consistent with it being an intermediate-mass star. The HerschelHIFI spectra show clear detection of H_{2}^{16}O and H_{2}^{17}O while H_{2}^{18}O is missing, consistent with
the prediction of hot bottom burning which occurs in stars with an initial mass ≥ 5 M_{ʘ}. The
star is currently losing mass at a high rate of a few 10^{-4} M_{ʘ} yr^{-1} which is thought to commence
in the past ∼ 200 years. We present new ALMA CO J=3-2 image which show that this high
mass loss (superwind) region is compact, surrounded by extended shells of lower mass loss
Efectos del entrenamiento interválico de alta intensidad durante el periodo transitorio en jugadores de fútbol sub-19
Actualmente existe un creciente interés por la aplicación del entrenamiento interválico de alta intensidad (HIIT) en fútbol (Buchheit et al. 2013). La eficacia mostrada por esta metodología de entrenamiento para mejorar las variables del rendimiento ha provocado una mayor aplicación en deportes colectivos (Iaia et al. 2009). Sin embargo, es escasa la literatura científica acerca de su impacto en fútbol. Por ello, el objetivo del trabajo es comparar los efectos sobre el rendimiento del HIIT versus entrenamiento tradicional durante el periodo transitorio invernal en jugadores de fútbol sub-19
Revista del Consejo Superior de Investigaciones Científicas
Actividad trófica de limícolas invernantes en salinas y cultivos piscícolas de la bahía de CádizUso de microhábitat del ratón de campo (Apodemus sylvatycus L.) en robledales y áreas ecotonales del Pirineo.Dieta de los pollos de tres especies simpátricas de alcaudones (Lanius spp.): variaciones con la edad, estacionales e interespecíficasOcupación de distintos modelos de nidal por el estornino negro (Sturnus unicolor)Estudio comparado sobre la biología de la reproducción de tres especies simpátricas de alcaudones (real Lanius excubitor, dorsirrojo L. collurio y común L. senatorFluctuación estacional del peso corporal de los machos adultos de Arvicola sapidus MILLER, 1908 (Rodentia, Arvicolidae)Acerca del significado de los ataques de alcaudones Lanius spp. sobre aves.Distribución de los emididos Mauremys leprosa, SCHW (1812) y Emys orbicularis, L. (1758) de la provincia de Badajoz. Factores que puedieran influir en sus áreas de ocupaciónDeterminación de la edad relativa en la rata de agua meridional, Arvicola sapidus MILLER, 1908 (Rodentia, Arvicolidae)Activity pattern, home range and habitat preference by coyotes (Canis latrans) in the Mapimi Biosphere Reserve of the Chihuahuan Desert, Mexico.Características de los refugios diarios y estacionales de Testudo graeca en DoñanaDieta del gato cimarrón (Felis catus L.) en el piso basal del Macízo de Teno (Noroeste de Tenerife)Peer reviewe
StarHorse: A Bayesian tool for determining stellar masses, ages, distances, and extinctions for field stars
Understanding the formation and evolution of our Galaxy requires accurate
distances, ages and chemistry for large populations of field stars. Here we
present several updates to our spectro-photometric distance code, that can now
also be used to estimate ages, masses, and extinctions for individual stars.
Given a set of measured spectro-photometric parameters, we calculate the
posterior probability distribution over a given grid of stellar evolutionary
models, using flexible Galactic stellar-population priors. The code (called
{\tt StarHorse}) can acommodate different observational datasets, prior
options, partially missing data, and the inclusion of parallax information into
the estimated probabilities. We validate the code using a variety of simulated
stars as well as real stars with parameters determined from asteroseismology,
eclipsing binaries, and isochrone fits to star clusters. Our main goal in this
validation process is to test the applicability of the code to field stars with
known {\it Gaia}-like parallaxes. The typical internal precision (obtained from
realistic simulations of an APOGEE+Gaia-like sample) are in
distance, in age, in mass, and mag in
. The median external precision (derived from comparisons with earlier
work for real stars) varies with the sample used, but lies in the range of
for distances, for ages,
for masses, and mag for . We provide StarHorse distances and
extinctions for the APOGEE DR14, RAVE DR5, GES DR3 and GALAH DR1 catalogues.Comment: 21 pages, 12 figures, accepte
A theoretical study of the Pnma and R3m phases of Sb2S3, Bi2S3, and Sb2Se3
[EN]
We report a comparative theoretical study of the Pnma and R3m phases of Sb2S3, Bi2S3, and Sb2Se3 close to ambient pressure. Our enthalpy calculations at 0 K show that at ambient pressure the R3m (tetradymite-like) phase of Sb2Se3 is energetically more stable than the Pnma phase, contrary to what is observed for Sb2S3 and Bi2S3, and irrespective of the exchange-correlation functional employed in the calculations. The result for Sb2Se3 is in contradiction to experiments in which all three compounds are usually grown in the Pnma phase. This result is further confirmed by free-energy calculations taking into account the temperature dependence of unit-cell volumes and phonon frequencies. Lattice dynamics and elastic tensor calculations further show that both the Pnma and R3m phases of Sb2Se3 are dynamically and mechanically stable at zero applied pressure. Since these results suggest that the formation of the R3m phase of Sb2Se3 should be feasible under close to ambient conditions, we provide a theoretical crystal structure and simulated Raman and infrared spectra to help in its identification. We also discuss the results of the two published works that have claimed to have synthesized tetradymite-like Sb2Se3. Finally, the stability of the R3m phase across the three group-15 A(2)X(3) sesquichalcogenides is analysed based on their van der Waals gap and X-X in-plane geometry.This publication is part of the MALTA Consolider Team network (RED2018-102612-T) (MINECO/AEI/10.13039/501100003329), and is supported by I + D + i project PID2019-106383GB41/42/43 (MCIN/AEI/10.13039/501100011033), by the PROMETEO/2018/123(EFIMAT) and CIPROM/2021/075 (GREENMAT) projects (Generalitat Valenciana), and by the European Union Horizon 2020 research and innovation programme under a Marie Sklodowska-Curie grant agreement (785789-COMEX). E. L. d. S., A. M., and P. R.-H. acknowledge computing time provided on the MALTA-Cluster at the University of Oviedo and on the MareNostrum facility through Red Espanola de Supercomputacion (RES) with technical support provided by the Barcelona Supercomputing Center (QCM-2018-3-0032). E. L. d. S. also acknowledges the Network of Extreme Conditions Laboratories (NECL), financed by FCT and co-financed by NORTE 2020 through the Portugal 2020 and FEDER programmes. J. M. S. is grateful to UK Research and Innovation for the support of a Future Leaders Fellowship (MR/T043121/1) and to the University of Manchester for the previous support of a Presidential Fellowship.Da Silva, EL.; Skelton, JM.; Rodríguez-Hernández, P.; Muñoz, A.; Santos, MC.; Martínez-García, D.; Vilaplana Cerda, RI.... (2022). A theoretical study of the Pnma and R3m phases of Sb2S3, Bi2S3, and Sb2Se3. Journal of Materials Chemistry C. 10(40):15061-15074. https://doi.org/10.1039/d2tc01484j1506115074104
Pervasive surveillance-agent system based on wireless sensor networks: design and deployment
Nowadays, proliferation of embedded systems is enhancing the possibilities of gathering information by using wireless sensor networks (WSNs). Flexibility and ease of installation make these kinds of pervasive networks suitable for security and surveillance environments. Moreover, the risk for humans to be exposed to these functions is minimized when using these networks. In this paper, a virtual perimeter surveillance agent, which has been designed to detect any person crossing an invisible barrier around a marked perimeter and send an alarm notification to the security staff, is presented. This agent works in a state of 'low power consumption' until there is a crossing on the perimeter. In our approach, the 'intelligence' of the agent has been distributed by using mobile nodes in order to discern the cause of the event of presence. This feature contributes to saving both processing resources and power consumption since the required code that detects presence is the only system installed. The research work described in this paper illustrates our experience in the development of a surveillance system using WNSs for a practical application as well as its evaluation in real-world deployments. This mechanism plays an important role in providing confidence in ensuring safety to our environment
Sutton Naevi as melanoma simulators: Can confocal microscopy help in the diagnosis?
Sutton naevi can sometimes present a challenging appearance with atypical presentation, also by dermoscopy. Reflectance confocal microscopy could help in making a diagnosis. This study prospectively collected two groups of Sutton nevi: the first one was composed by typical white halo naevi monitored for one year (13, 23%) and the second one was made up of atypical lesions excised in order to rule out melanoma, which were histologically diagnosed as Sutton naevi (21, 37%). These two groups of Sutton naevi were compared to a retrospectively collected cohort of thin melanomas with histologic regression features (23, 40%). On dermoscopy, atypical Sutton naevi and melanomas were indistinguishable. Reflectance confocal microscopy demonstrated significant differences at the dermo-epidermal junction: marked dermo-epidermal junction thickening and non-edged papilla were associated with melanoma, while the presence of nests was associated with Sutton naevi. However, reflectance confocal microscopy also detected marked intraepidermal pagetoid cells in Sutton naevi that were a combination of MelanA+ and CD1a+ cells. Sutton naevi can simulate melanoma, under both dermoscopy and reflectance confocal microscopy. Nevertheless, relevant confocal dermo-epidermal junction features and the clinical scenario can be helpful to make a final diagnosis, especially in those situations where melanoma must be ruled out
Analysis of the Use and Applicability of Different Variables for the Prescription of Relative Intensity in Bench Press Exercise
The aim of the study was to analyze the use of variables such as % of one-repetition maximum (1RM) and number of maximal repetitions (xRM) with execution velocity to define and control the intensity of resistance training in bench press exercise. Hence, exercise professionals will achieve better control of training through a greater understanding of its variables. Methods: In this cross-sectional study, fifty male physical education students were divided into four groups according to their relative strength ratio (RSR) and performed a 1RM bench press test (T1). In the second test, participants performed repetitions to exhaustion (T2), using a relative load corresponding to 70% 1RM determined through the mean propulsive velocity (MPV) obtained from the individual load–velocity relationship. This same test was repeated a week later (T3). Tests were monitored according to the MPV of each repetition and blood lactate values (LACT). Results: Regarding MPV, the best (fastest) repetition of the set (MPVrep Best) values were similar between groups (0.62 m·s−1–0.64 m·s−1), with significant differences in relation to the high RSR group (p 0.05). Average LACT values (5.72 mmol·L−1) showed significant differences between the Background: Medium RSR and Very Low RSR groups. No significant differences were found (p > 0.05) between T2 and T3 with regards to MNR, MPVrep Best, or MPVrep Last, with little variability seen between participants. Conclusions: The use of variables such as the 1RM, estimated using an absolute load value, or an MNR do not allow an adequate degree of precision to prescribe and control the relative intensity of resistance training. Besides, execution velocity control can offer an adequate alternative to guarantee an accurate prescription of intensity with regard to resistance training.Sección Deptal. de Radiología, Rehabilitación y Fisioterapia (Enfermería)Fac. de Enfermería, Fisioterapia y PodologíaTRUEpu
Realization of Polarization Control in High-Order Harmonic Generation
The nature of high-order harmonic generation process limits the harmonics emission to linear polarization. In this paper, we review the recent progress to generate elliptically or circularly polarized high-harmonic EUV pulses. We further demonstrate how complete control of polarization state of isolated high-harmonic pulse can be realized today by noncollinear focusing of two driving pulses with identical ellipticity but counter-rotating helicity. This paper opens a path towards the study of the fastest dynamics--down to attosecond time scales--in circular dichroism of magnetic materials, chiral molecules, and electronic spin motion.Taiwan Ministry of Science and Technology; Academia Sinica; Junta de Castilla y León; Ministerio de Economía y Competitividad; Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation; Ministerio de Ciencia, Innovación y Universidades for a Ramón y Cajal; European Social Fund; Ministerio de Educación, Cultura y Deporte
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