225 research outputs found
KOS - RABCEWICZ - ZUBKOWSKI: International cooperation in civil and comercial procedure (American Continent). Canadian Inter-American Research Institute. University of Ottawa Press, Ottawa, Canadá, 1975, 582 págs. [RECENSIÓN]
Evolution of massive stars with new hydrodynamic wind models
Here we present evolutionary models for a set of massive stars, introducing a
new prescription for the mass-loss rate obtained from hydrodynamical
calculations in which the wind velocity profile, , and the
line-acceleration, , are obtained in a self consistently way.
Replacing mass-loss rates at the Main Sequence stage from the standard Vink's
formula by our new recipe, we generate a new set of evolutionary tracks for
and and metallicities
(Galactic), (LMC), and (SMC).
Our new derived formula for mass-loss rate predicts a dependence , where is not longer constant but dependent on the stellar
mass: ranging from when , to when
.
We found that models adopting the new recipe for retain more mass
during their evolution, which is expressed in larger radii and consequently
more luminous tracks over the Hertzsprung-Russell diagram. These differences
are more prominent for the cases of and 120 at
solar metallicity, where we found self-consistent tracks are dex
brighter and keep extra mass up to 20 , compared with the classical
models using the previous formulation for mass-loss rate.
Moreover, we observed remarkable differences for the evolution of the
radionuclide isotope Al in the core and the surface of the star. Since
are weaker than the commonly adopted values for evolutionary
tracks, self-consistent tracks predict a later modification in the abundance
number of Al in the stellar winds. This new behaviour could provide
useful information about the real contribution of this isotope from massive
stars to the Galactic interstellar medium.Comment: Accepted for publication in Astronomy & Astrophysic
Accessible opera : overcoming linguistic and sensorial barriers
The desire to make media available for all has been rapidly accepted and implemented by most European countries. Opera, as one of the many audiovisual representations, also falls under the category of production which needs to be made accessible and this article aims to analyse how opera has gone through a complete transformation to become a cultural event for all, overcoming not only linguistic but also sensorial barriers. The first part of the article analyses the various forms of translation associated with opera and the main challenges they entail. The second presents different systems used to make opera accessible to the sensorially challenged, highlighting their main difficulties. Examples from research carried out at the Barcelona's Liceu opera house are presented to illustrate various modalities, especially audio description. All in all, it is our aim to show how translated-related processes have made it possible to open opera to a wider audience despite some initial reluctance
Variations on the Pear Tree Experiment : different variables, new results?
Inspired by the Pear Stories Project, the Pear Tree Project has investigated how different cultures and languages describe the same film in order to apply its findings to audio description (AD). Participants from different countries were asked to "write down what they saw" in a controlled setting. This article proposes an alternative experiment, also based on the original Pear Stories Project, which aims to shed light on two issues: how different describer profiles (translation students with AD training/without AD training) and different instructions concerning the target audience profiles (blind/non-blind) could alter the final production. The results are analysed in this paper, taking into account the elements covered in the original Pear Stories Project as well as some additional elements proposed by the authors
Terminological challenges in the translation of science documentaries: a case-study
This article aims to describe some of the main terminological problems audiovisual translators have to face when dealing with the translation of science documentaries, specifically in the English-Catalan combination. The first section of the article presents some theoretical concepts which underlie this research and which are taken, for the most part, from Cabré's Communicative Theory of Terminology. Then, specific terminological problems audiovisual translators have to solve are described using the data provided by a corpus of four science documentaries lasting approximately 50 minutes each. These challenges include identifying a term, understanding a term, finding the right equivalent, dealing with the absence of an adequate equivalent, solving denominative variations, choosing between in vivo and in vitro terminology, and overcoming mistranscriptions
Differentiating lower motor neuron syndromes
Lower motor neuron (LMN) syndromes typically present with muscle wasting and weakness and may arise from pathology affecting the distal motor nerve up to the level of the anterior horn cell. A variety of hereditary causes are recognised, including spinal muscular atrophy, distal hereditary motor neuropathy and LMN variants of familial motor neuron disease. Recent genetic advances have resulted in the identification of a variety of disease-causing mutations. Immune-mediated disorders, including multifocal motor neuropathy and variants of chronic inflammatory demyelinating polyneuropathy, account for a proportion of LMN presentations and are important to recognise, as effective treatments are available. The present review will outline the spectrum of LMN syndromes that may develop in adulthood and provide a framework for the clinician assessing a patient presenting with predominantly LMN features
Selective loss of the uncoupling protein from light versus heavy mitochondria of brown adipocytes after a decrease in noradrenergic stimulation in vivo and in vitro
Investigating potential planetary nebula/cluster pairs
Publisher's Version/PDFContext. Fundamental parameters characterizing the end-state of intermediate-mass stars may be constrained by discovering planetary nebulae (PNe) in open clusters (OCs). Cluster membership may be exploited to establish the distance, luminosity, age, and physical size for PNe, and the intrinsic luminosity and mass of its central star. Aims. Four potential PN-OC associations were investigated to assess the cluster membership for the PNe. Methods. Radial velocities were measured from intermediate-resolution optical spectra, complemented with previous estimates in the literature.When the radial velocity study supported the PN/OC association, we analyzed whether other parameters (e.g., age, distance, reddening, central star brightness) were consistent with this conclusion. Results. Our measurements imply that the PNe VBe 3 and HeFa 1 are not members of the OCs NGC5999 and NGC6067, respectively, and that they very likely belong to the background bulge population. Conversely, consistent radial velocities indicate that NGC2452/NGC 2453 could be associated, but our results are not conclusive so additional observations are warranted. Finally, we demonstrate that all the available information point to He 2-86 being a young, highly internally obscured PN member of NGC4463. New near-infrared photometry acquired via the Vista Variables in the Via Lactea ESO public survey was used in tandem with existing UBV photometry to measure the distance, reddening, and age of NGC4463, finding d = 1.55 ± 0.10 kpc, E(B − V) = 0.41 ± 0.02, and τ = 65 ± 10 Myr, respectively. The same values should be adopted for the PN if the proposed cluster membership is confirme
Changes induced by fasting and dietetic obesity in thermogenic parameters of rat brown adipose tissue mitochondrial subpopulations
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