Scalar-tensor theory with EGB term from Einstein Chern-Simons gravity

It is shown that the compactification a la Randall Sundrum of the so called, five dimensional Einstein Chern Simons action gravity leads to an action for a four dimensional scalar tensor gravity that includes a Gauss Bonnet term, which belongs to a particular case of the action of the Horndeski theory. The five dimensional action includes new gravitational degrees of freedom that were introduced requiring that the action be invariant under symmetries greater than the usual Poincare or (A)dS symmetries, namely the so called generalized Poincare algebras B5.Comment: To be published in Nucl. Phys.

A gamma ray burst with small contamination

We present a scenario (SupraNova) for the formation of GRBs occurring when a supramassive neutron star (SMNS) loses so much angular momentum that centrifugal support against self--gravity becomes impossible, and the star implodes to a black hole. This may be the baryon--cleanest environment proposed so far, because the SN explosion in which the SMNS formed swept the medium surrounding the remnant, and the quickly spinning remnant loses energy through magnetic dipole radiation at a rate exceeding its Eddington luminosity by some four orders of magnitude. The implosion is adiabatic because neutrinos have short mean free paths, and silent, given the prompt collapse of the polar caps. However, a mass ~ 0.1 M_solar in the equatorial belt can easily reach centrifugal equilibrium. The mechanism of energy extraction is via the conversion of the Poynting flux (due to the large--scale magnetic field locked into the minitorus) into a magnetized relativistic wind. Occasionally this model will produce quickly decaying, or non--detectable afterglows.Comment: To appear in The Astrophysical Journal Letters. AASTeX LateX, no figure

The Cauchy problem of scalar-tensor theories of gravity

The 3+1 formulation of scalar-tensor theories of gravity (STT) is obtained in the physical (Jordan) frame departing from the 4+0 covariant field equations. Contrary to the common belief (folklore), the new system of ADM-like equations shows that the Cauchy problem of STT is well formulated (in the sense that the whole system of evolution equations is of first order in the time-derivative). This is the first step towards a full first order (in time and space) formulation from which a subsequent hyperbolicity analysis (a well-posedness determination) can be performed. Several gauge (lapse and shift) conditions are considered and implemented for STT. In particular, a generalization of the harmonic gauge for STT allows us to prove the well posedness of the STT using a second order analysis which is very similar to the one used in general relativity. Some spacetimes of astrophysical and cosmological interest are considered as specific applications. Several appendices complement the ideas of the main part of the paper.Comment: 29 pages Revtex; typos corrected; references added and updated; a shorter version of this paper was published in Classical and Quantum Gravit

Towards a normative diagnosis tool in an organizational context: applying the Evaluative Model of the Normative Appeals

Basándonos en el Modelo Evaluativo de Apelaciones Normativas (EMNA), diseñamos una herramienta de diagnóstico que permite prever el grado de cumplimiento de un conjunto de normas por parte de los empleados. Primero realizamos dos estudios transversales para aplicar la herramienta en una muestra general de trabajadores (Estudio 1, N = 382) y en una muestra de empleados de una organización específica (Estudio 2, N = 82). Dos meses más tarde comprobamos en la misma organización (Estudio 3, N = 80) si la disposición a cumplir una serie de llamamientos normativos se ajustaba al diagnóstico generado en el Estudio 2. Los resultados apoyan la validez de la herramienta para diagnosticar la percepción y la disposición a cumplir los llamamientos normativosBased on the Evaluative Model of Normative Appeals (EMNA), we designed a diagnosis tool that allows forecasting the extent to which employees may comply with a set of norms. We first performed two cross-sectional studies to apply the tool within a general sample of workers (Study 1, N = 382) and within a sample of employees of a specific organization (Study 2, N = 82). Two months later we tested in the same organization (Study 3, N = 80) whether the willingness to comply with a set of normative appeals was aligned with the diagnosis generated in Study 2. The results support the validity of the tool to diagnose the perception of and willingness to comply with normative appeal

CoryneRegNet 6.0—Updated database content, new analysis methods and novel features focusing on community demands

Post-genomic analysis techniques such as next-generation sequencing have produced vast amounts of data about micro organisms including genetic sequences, their functional annotations and gene regulatory interactions. The latter are genetic mechanisms that control a cell's characteristics, for instance, pathogenicity as well as survival and reproduction strategies. CoryneRegNet is the reference database and analysis platform for corynebacterial gene regulatory networks. In this article we introduce the updated version 6.0 of CoryneRegNet and describe the updated database content which includes, 6352 corynebacterial regulatory interactions compared with 4928 interactions in release 5.0 and 3235 regulations in release 4.0, respectively. We also demonstrate how we support the community by integrating analysis and visualization features for transiently imported custom data, such as gene regulatory interactions. Furthermore, with release 6.0, we provide easy-to-use functions that allow the user to submit data for persistent storage with the CoryneRegNet database. Thus, it offers important options to its users in terms of community demands. CoryneRegNet is publicly available at http://www.coryneregnet.de

Soil Damping and Its Use in Dynamic Analyses

Soil response under dynamic loading has been modeled using linear-viscoelasticity for many decades. The definitions of various damping-related quantities are reviewed and the implications of their use in the analysis of continuous masses are given. The selection of an equivalent damping ratio as a parameter for modeling damping in most geotechnical applications is discussed together with the assumptions underlying the selection procedure. The techniques for damping determination using laboratory testing are summarized, emphasizing the influence that factors such as apparatus type, loading path, rate of loading, and strain level have on the measurement. Disturbance effects in samples recovered from the ground are discussed and contrasted with the advantages and disadvantages of emerging techniques for in-situ determination of damping. Finally, the paper addresses the importance of selecting damping values for different types of analyses in earthquake geotechnical engineering and of correctly accounting for radiation damping

CONTRIBUTO DA CLIMATOLOGIA PARA A RECUPERAÇÃO DA RIBEIRA DA PARDIELA

Todos os afluentes do rio Guadiana em território português são rios temporários de características sazonais que apresentam caudal superficial apenas durante os meses com precipitação. Este tipo de sistemas ocorre naturalmente em regiões de clima Mediterrânico e de clima semi-árido, estando também presentes noutras regiões da Europa, normalmente associadas à geologia de características calcárias extremamente permeável. Para preservar e reabilitar estes sistemas é necessário uma abordagem multidisciplinar que permita conhecer o seu funcionamento assim como a evolução das suas características ao longo do tempo

Enhanced charm hadroproduction due to nonlinear corrections to the DGLAP equations

We have studied the effects of nonlinear scale evolution of the parton distribution functions to charm production in $pp$ collisions at center-of-mass energies of 5.5, 8.8 and 14 TeV. We find that the differential charm cross section can be enhanced up to a factor of 4-5 at low $p_T$. The enhancement is quite sensitive to the charm quark mass and the renormalization/factorization scales.Comment: 4 pages, 3 eps-figures. To appear in the proceedings of the seventeenth international conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2004