Limits on Cosmic Chiral Vortons

We study chiral vorton production for Witten-type superconducting string models in the context of a recently developed analytic formalism. We delineate three distinct scenarios: First, a low energy regime (including the electroweak scale) where vortons can be a source of dark matter. Secondly, an intermediate energy regime where the vorton density is too high to be compatible with the standard cosmology (thereby excluding these models). Finally, a high energy regime (including the GUT scale) in which no vortons are expected to form. The vorton density is most sensitive to the order of the string-forming phase transition and relatively insensitive to the current-forming transition. For a second-order string transition, vorton production is cosmologically disastrous for the range 10^{-28}\lsim G\mu \lsim 10^{-10} (10^{5} GeV \lsim T_{c} \lsim 10^{14} GeV), while for the first-order case we can only exclude 10^{-20}\lsim G\mu \lsim 10^{-14} (10^{9} GeV \lsim T_{c} \lsim 10^{12} GeV). We provide a fitting formula which summarises our results.Comment: 9 LaTeX pages, 5 .eps files; submitted to Phys.Lett.

UV, optical and near-IR diagnostics of massive stars

We present an overview of a few spectroscopic diagnostics of massive stars. We explore the following wavelength ranges: UV (1000 to 2000 A), optical (4000--7000 A) and near-infrared (mainly H and K bands). The diagnostics we highlight are available in O and Wolf-Rayet stars as well as in B supergiants. We focus on the following parameters: effective temperature, gravity, surface abundances, luminosity, mass loss rate, terminal velocity, wind clumping, rotation/macroturbulence and surface magnetic field.Comment: 12 pages, 8 figures. Proceedings of the 39th Li\`ege Astrophysical Colloquium "The multi-wavelength view of hot, massive stars". Referee's comments include

Joint Dispersion Model with a Flexible Link

The objective is to model longitudinal and survival data jointly taking into account the dependence between the two responses in a real HIV/AIDS dataset using a shared parameter approach inside a Bayesian framework. We propose a linear mixed effects dispersion model to adjust the CD4 longitudinal biomarker data with a between-individual heterogeneity in the mean and variance. In doing so we are relaxing the usual assumption of a common variance for the longitudinal residuals. A hazard regression model is considered in addition to model the time since HIV/AIDS diagnostic until failure, being the coefficients, accounting for the linking between the longitudinal and survival processes, time-varying. This flexibility is specified using Penalized Splines and allows the relationship to vary in time. Because heteroscedasticity may be related with the survival, the standard deviation is considered as a covariate in the hazard model, thus enabling to study the effect of the CD4 counts' stability on the survival. The proposed framework outperforms the most used joint models, highlighting the importance in correctly taking account the individual heterogeneity for the measurement errors variance and the evolution of the disease over time in bringing new insights to better understand this biomarker-survival relation.Comment: 27 pages, 3 figures, 2 table

Economic Liberty, Price Control, and Environmental Harm

One core question in contemporary political economy is whether economic liberties should be constitutionally protected as basic rights. In this article I do not provide a positive argument for the view that economic liberties are basic rights. Rather, I seek to provide a reason for not embracing the opposing view, i.e. that economic liberties should not be constitutionally protected as basic rights. Based on Hayek’s theory of price as signal, I argue that price control, a view usually associated with high liberals, and sometimes endorsed by moderate welfarists, is environmentally sub-optimal

J/Psi and Psi' Suppression in Hadronic Matter

We present a microscopic calculation of the breakup cross sections of $J/\psi$ and $\psi'$ on pions and nucleons as a function of the kinetic energy. These cross sections are used for the investigation of the $J/\psi$ to continuum and $\psi'/J/\psi$ ratios in ultrarelativistic heavy ion collisions. The contribution of produced comoving pions to the $\psi'/J/\psi$ signal is calculated. While this model can account for the data, the uncertainties in the parameter values do not allow to exclude the possibility of additional sources for charmonium absorption, like a resonance gas or the quark gluon plasma.Comment: LaTeX, 6 pages including 2 EPS files, to be published in Prog. Part. Nucl. Phys., [email protected]

The art of tropical travel, 1768-1830

Book synopsis: Georgian Geographies provides an innovative interdisciplinary examination of the geographical nature of culture and society in eighteenth-century Britain and the British world. The book's introduction identifies the key areas of study as the geographical constitution of empire, the Enlightenment and the public sphere. These themes are explored by examining the connections between space, place and landscape in the eighteenth century in relation to the emergent empire in the Caribbean and north-west America, and in Britain itself. The topics considered include landscape painting, London's art world, geography's book, mapping, the geography of erotic fiction, provincial science, and the production of domestic space in the early English novel. It will be an essential contribution to eighteenth-century studies for research and teaching staff, postgraduates and advanced undergraduate students in geography, history, literary studies, the history of art, postcolonial studies and the history of science

Fatores determinantes da eficiência do setor bancário em Portugal: uma aplicação através de modelos de regressão fracional

The participation in the Euro area and the current financial crisis substantially conditioned the development of the Portuguese banking industry, for which is expected a continuous fall in income and a growing competitive pressure, improving the need to look carefully to issues as efficiency as an essential survival factor. Efficiency indicators of the main banks operating in Portugal were measured through DEA methodology. The application of two-stage models allowed circumventing the usual problems inherent to the coexistence of the production and intermediation approaches. The application of regression for proportions, more appropriate than traditional linear and Tobit regressions, to deal with the fractional nature of the DEA scores, allowed the identification of efficiency determinant factors for the main banks operating in Portugal. The fractional regression models demonstrate evidence of improved specification comparing to traditional regression models. The variables that appear to major influence on overall efficiency are internationalization, size and type of ownership of capital.info:eu-repo/semantics/publishedVersio