No abstract

We analyse holographic field theory dual to Lovelock Chern-Simons AdS Gravity in higher dimensions using first order formalism. We first find asymptotic symmetries in the AdS sector showing that they consist of local translations, local Lorentz rotations, dilatations and non-Abelian gauge transformations. Then, we compute 1-point functions of energy-momentum and spin currents in a dual conformal field theory and write Ward identities. We find that the holographic theory possesses Weyl anomaly and also breaks non-Abelian gauge symmetry at the quantum level. IntroductionThe AdS/CFT correspondence [1] relates the fields in (d + 1)-dimensional asymptotically anti-de Sitter (AAdS) space and correlators in a d-dimensional Conformal Field Theory (CFT). These two theories are dual in the asymptotic sector of gravity, such that the weak coupling regime of one is related to the strong coupling regime of another. For a weak gravitational coupling, the bulk theory is well-described by its semiclassical approximation, leading to the form of the duality most often used.Since its discovery, the correspondence tools have been applied to many strongly coupled systems, giving rise to new insights into their dynamics, for example in hydrodynamics [2] and condensed matter systems such as superconductors [3].On the other hand, much effort has been invested in analysing the duality in semiclassical approximation of a bulk theory, with twofold purpose. First, it enables to test the conjecture itself. Second, it helps us to gain the knowledge about strongly coupled systems which are non-perturbative and not very well understood. However, most of this investigation deals with Riemannian geometry of bulk spacetime, see for example [3,4,5,6,7,8], while a more general structure based on Riemann-Cartan geometry, where both torsion and curvature determine gravitational dynamics, is mostly underinvestigated. One of the first * Email addresses: olivera.miskovic@pucv.cl, cbranislav@ipb.ac.rs, dsimic@ipb.ac.rs 1 studies of Riemann-Cartan holography used first order formalism to obtain a holographic dual of Chern-Simons AdS gravity in five dimensions [9]. After that, in three dimensions, holographic dual to the Mielke-Baekler model was analysed in [10], and to the most general parity-preserving three-dimensional gravity with propagating torsion in [11]. The physical interpretation of torsional degrees of freedom as carriers of a non-trivial gravitational magnetic field in 4D Einstein-Cartan gravity was discussed in [12].Studying holographic duals of gravity with torsion has many benefits. Since its setup is more general, it also contains the results of torsion-free gravity. One of the very important features is that treating vielbein and spin connection as independent dynamical variables simplifies calculations to great extent. In Ref.[11], it was shown that for three dimensional bulk gravity conservation laws of the boundary theory take the same form in RiemannCartan and Riemannian theory when the boundary torsion is set to zero. Thus, i...

No abstract

In the present study, we examined cytotoxicity and extracellular and intracellular antiviral activity of frac­tionated extracts of wild and cultivated sage Salvia officinalis L. (Lamiaceae) in vitro using the WISH-VSV model system. Extracts were obtained by fractionating depigmented ethanol extracts of sage plants with supercritical CO2 at different pressures. Cytotoxicity was determined by examining cellular morphology in situ with the aid of a colorimetric micromethod and by cell staining with trypan blue. The fraction of distilled cultivated sage obtained at CO2 pressure of 300 bars and temperature of 60°C (149/3) was the most cytotoxic, with CTD10 44 μg/ml. That of non-distilled cultivated sage obtained at CO2 pressure of 500 bars and temperature of 100°C (144/5) was the least toxic (CTD10 199 μg/ml). Moreover, 144/5 had an antiviral effect at the intracellular level: when added 5 hours before VSV infection, it caused 100% reduction of CPE at concentrations of 99.5 and 199.0 μg/ml; when added after virus penetration had occurred, the same concentrations caused 35 and 60% reduction, respectively. The obtained results indicate that antiviral activity of 144/5 involves inhibition of the early steps of the virus infective cycle without a direct virucidal effect. Abbreviations: WISH - human amnion epithelial cells, VSV - vesicular stomatitis virus, HSV - herpes simplex virus, CPE - cytopathic effect, IS - selectivity index, TCID50 - tissue culture infective dose, CTD10 - 10% cytotoxic concentrations

Wireless sensor networks are now used in various fields. The information transmitted in the wireless sensor networks is very sensitive, so the security issue is very important. DOS (denial of service) attacks are a fundamental threat to the functioning of wireless sensor networks. This paper describes some of the most common DOS attacks and potential methods of protection against them. The case study shows one of the most frequent attacks on wireless sensor networks -the interference attack. In the introduction of this paper authors assume that the attack interference can cause significant obstruction of wireless sensor networks. This assumption has been proved in the case study through simulation scenario and simulation results. RESUMENLas redes de sensores inalámbricos se utilizan ahora en varios campos. La información transmitida en las redes de sensores inalámbricos es muy delicada, por lo que el tema de la seguridad es muy importante. Los ataques de DOS (Denegación de servicio) son una amenaza fundamental para el funcionamiento de las redes de sensores inalámbricos. Este documento describe algunos de los ataques DOS más comunes y los posibles métodos de protección contra ellos. El estudio de caso muestra uno de los ataques más frecuentes a las redes de sensores inalámbricos: el ataque de interferencia. En la introducción de este artículo, los autores suponen que la interferencia de ataque puede causar una obstrucción significativa de las redes de sensores inalámbricos. Esta suposición se ha demostrado en el estudio de caso a través de escenarios de simulación y los resultados de estas simulaciones.Palabras clave: Redes de sensores inalámbricos, detección de intrusión, comunicación inalámbrica, seguridad del sistema de comunicación, interferencia de radiofrecuencia.

We investigate near-horizon geometry of the rotating Bañados Teiteilboim Zanelli (BTZ) black hole with torsion. Our main motivation is to gain insight into the role of torsion in the near-horizon geometry, which is well understood in the Riemannian case. We obtain that near-horizon geometry represents a generalization of AdS selfdual orbifold with non-trivial torsion. We analyze its asymptotic structure and derive the corresponding algebra of asymptotic symmetries, which consists of chiral Virasoro and centrally extended u(1) Kac-Moody algebra. *

No abstract

No abstract