2,891 research outputs found
Particle collisions near a three-dimensional warped AdS black hole
In this paper we consider the warped AdS black hole solution of
topologically massive gravity with a negative cosmological constant, and we
investigate the possibility that it acts as a particle accelerator by analyzing
the energy in the center of mass (CM) frame of two colliding particles in the
vicinity of its horizon, which is known as the Ba\~nados, Silk and West (BSW)
process. Mainly, we show that the critical angular momentum of the
particle decreases when the parameter that controls the stretching deformation
() increases. Also, we show that despite the particle with can exist
for certain values of the conserved energy outside the horizon, it will never
reach the event horizon; therefore, the black hole can not act as a particle
accelerator with arbitrarily high CM energy on the event horizon. However, such
particle could also exist inside the outer horizon being the BSW process
possible on the inner horizon. On the other hand, for the extremal warped
AdS black hole, the particle with and energy could exist
outside the event horizon and the CM energy blows up on the event horizon if
its conserved energy fulfill the condition
, being the BSW process possible.Comment: 11 pages, 6 figure
Fermionic greybody factors of two and five-dimensional dilatonic black holes
We study fermionic perturbations in the background of a two and
five-dimensional dilatonic black holes. Then, we compute the reflection and
transmission coefficients and the absorption cross section for fermionic
fields, and we show numerically that the absorption cross section vanishes in
the low and high frequency limit. Also we find that beyond a certain value of
the horizon radius the absorption cross section for five-dimensional
dilatonic black hole is constant. Besides, we have find that the absorption
cross section decreases for higher angular momentum, and it decreases when the
mass of the fermionic field increases.Comment: Accepted in EPJ
Structure of Ethical Governance in Commercial Advertising. Review of the Autocontrol Model from a Discursive Stakeholder Management
In competitive and global environments in which companies
operate commercial advertising plays a vital role that is essential
to have full responsibility. This responsibility involves in many
cases, self-regulation of advertising to ensure the guiding principles:
truthfulness, legality, honesty and loyalty. In Spain the governance
structure of Autocontrol came up with this goal in 1 995, where the
political, business and civil society spheres come together to try to
coordinate their action to promote advertising self-regulation. The
article focuses on a critical study of the governance system developed
by Autocontrol, self-regulatory organization of the Commercial
Communications, founded in 1 995 in Spain. With nearly twenty years
of business experience seems an appropriate time to review its management
and governance structure from an ethical point of view.
This goal will be accomplished using the discourse ethics and the stakeholder
management approach.En los entornos competitivos y globales en los que las empresas
desarrollan su actividad la publicidad comercial cumple un papel
vital que es fundamental llevar a cabo con plena responsabilidad.
Esta responsabilidad pasa, en muchas ocasiones, por una autorregulación
de la publicidad para garantizar los principios rectores de: veracidad,
legalidad, honestidad y lealtad. En España surgió con este
objetivo la estructura de gobernanza de Autocontrol en 1 995, donde
el ámbito político, empresarial y de la sociedad civil se dan la mano
para tratar de coordinar su acción para promover la autorregulación
publicitaria. El artículo se centra en un estudio crítico del sistema de
gobernanza desarrollado por Autocontrol, entidad de autorregulación
de la Comunicación Comercial, creada en 1 995 en España. Con una experiencia
cercana a los veinte años de andadura parece un momento
adecuado para revisar su estructura gerencial y de gobernanza desde
un punto de vista ético. Este objetivo se llevará a cabo utilizando la
ética discursiva y el enfoque gerencial de los stakeholders
Ethic and advertising self-regulation: A perspective from consumer associations
La búsqueda por promocionar unos estándares éticos mínimos de publicidad es una preocupación en los sistemas de autorregulación.
En España esta disciplina fue introducida en la práctica en 1995, año de la fundación de Autocontrol. El objetivo
de este artículo es examinar el punto de vista de las asociaciones de consumidores con respecto al funcionamiento de esta
asociación. Se desea conocer la valoración que las asociaciones realizan específicamente del sistema de reclamaciones de
Autocontrol, pieza clave (y única) para la participación de actores “externos” a la asociación. El método empleado es un
estudio de caso donde adquieren un peso especial las entrevistas a asociaciones de consumidores.The quest to promote minimum ethical advertising standards is a concern in self-regulatory systems. This practice was introduced
in Spain in 1995, the same year Autocontrol was founded. This article aims to examine how consumer associations
view the functions of Autocontrol; specifically, the assessment these associations make of the Autocontrol claims system
that is a key (and the only) part for any “external” actors to the association to be able to participate. The method used is a
case study in which interviews with consumer associations were especially relevant
Autocontrol: A Critical Study of Achievements and Challenges in the Pursuit of Ethical Advertising Through an Advertising Self-Regulation System
The theory and practice of advertising self-regulation have been evolving for decades in pursuit of basic standards for advertising quality. In Spain, this discipline was put into practice in 1995, the year the Association for the Self-Regulation of Commercial Communication (Autocontrol) was created. This article aims to examine in depth the functioning of the Spanish advertising self-regulation system, with special emphasis on the Advertising Jury, and explore to what extent some of the normative requirements of rigour, independence and participation can be considered to have been met. The paper is based on a case study in which interviews with Autocontrol members, Jury members and consumer associations have particular bearing. The results shed light on the achievements of Autocontrol’s self-regulation work and the challenges it still faces.The authors, who are members of the Spanish research project FI2013-47136-C2-2-P, would like to express their gratitude to all the association members and individuals who were interviewed during the study, and for their attention, help and patience during the research project. In addition, the authors would like to acknowledge and thank the anonymous reviewers for their comments, which have greatly improved this paper
Charged scalar field perturbations in Ernst black holes
We consider the propagation of a charged massive scalar field in the
background of a four-dimensional Ernst black hole and study its stability
analyzing the quasinormal modes (QNMs), which are calculated using the
semi-analytical Wentzel-Kramers-Brillouin method and numerically using the
continued fraction method. Mainly, we find that for a scalar field mass less
than a critical mass, the decay rate of the QNMs decreases when the harmonic
angular number increases; and for a scalar field mass greater than the
critical mass the behaviour is inverted, i.e, the longest-lived modes are
always the ones with the lowest angular number recovering the standard
behaviour. Also, we find a critical value of the external magnetic field, as
well as, a critical value of the scalar field charge that exhibit the same
behaviour with respect to the angular harmonic numbers. In addition, we show
that the spacetime allows stable quasibound states and we observe a splitting
of the spectrum due to the Zeeman effect. Finally, we show that the unstable
null geodesic in the equatorial plane is connected with the QNMs when the
azimuthal quantum number satisfy in the eikonal limit.Comment: 14 pages and 7 figures. arXiv admin note: text overlap with
arXiv:gr-qc/0211035 by other author
Relics and Historical Uses of Human Zootherapeutic Products in Contemporary Spanish Ethnoveterinary Medicine
Background: this review documents the wide repertoire of practices and remedies based on the use of human-derived products in Spanish ethnoveterinary medicine (EVM) from the early 20th century to the present. These practices are compared with historical data and those of other countries; (2) Methods: a search using advanced functions in the most important databases in the fields of ethnobiology, EVM, folklore, and ethnography was performed. Information was obtained from 29 documentary sources; (3) Results: from the search of the literature, 46 use-reports related to the veterinary use of human urine, menstrual fluid, saliva, breast milk, and faeces were recorded. These zootherapeutic resources are/were used to treat 20 animal diseases, in particular dermatological ailments. In addition, many practices of the magical-religious type are documented; (4) Conclusions: the veterinary uses described and analysed here are fundamental to the development of therapeutic tools and creating teaching and learning processes in new popular veterinary practices adapted to the users and those who demand them. The information collected could form a scientific foundation for future inventories of local veterinary knowledge (LVK) and research addressing the discovery of new drugs for livestock. This work contributes to the inventory of some uses, traditional practices, and rituals seriously threatened by the progressive loss of LVK in Europ
Present and future of the OTELO project
OTELO is an emission-line object survey carried out with the red tunable
filter of the instrument OSIRIS at the GTC, whose aim is to become the deepest
emission-line object survey to date. With 100% of the data of the first
pointing finally obtained in June 2014, we present here some aspects of the
processing of the data and the very first results of the OTELO survey. We also
explain the next steps to be followed in the near future.Comment: Oral contribution presented in the XI Scientific Meeting of the
Spanish Astronomical Society held on September 8-12, in Teruel, Spain (7
pages, 2 figures, 1 table). To appear in Highlights of Spanish Astrophysics
VIII, Proceedings of the XI Scientific Meeting of the Spanish Astronomical
Society. Eds. A. J. Cenarro, F. Figueras, C. Hern\'andez-Monteagudo, J.
Trujillo, L. Valdiviels
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