Nonlinear trend stationarity of real exchange rates: the case of the Mediterranean countries

The aim of this article is to provide additional evidence on the fulfilment of the Purchasing Power Parity hypothesis in the so-called Mediterranean countries. In order to test for the empirical validity of such hypothesis, we have applied two types of unit root tests. The first group is due to Bierens (1997) who generalizes the alternative hypothesis to nonlinear trend stationariry and, the second is the Leybourne, Newbold and Vougas (1998) approach that uses a nonlinear specification for the intercept and slope in order to detrend the series. The results suggest that the evidence in favour of the Purchasing Power Parity hypothesis increases when we allow for nonlinear alternatives

Bosonic D=11 supergravity from a generalized Chern-Simons action

It is shown that the action of the bosonic sector of D=11 supergravity may be obtained by means of a suitable scaling of the originally dimensionless fields of a generalized Chern-Simons action. This follows from the eleven-form CS-potential of the most general linear combination of closed, gauge invariant twelve-forms involving the sp(32)-valued two-form curvatures supplemented by a three-form field. In this construction, the role of the skewsymmetric four-index auxiliary function needed for the first order formulation of $D=11$ supergravity is played by the gauge field associated with the five Lorentz indices generator of the bosonic sp(32) subalgebra of osp(1|32).Comment: Misprints corrected, to appear in NPB plain latex, no figures, 25 page

La manipulación genética y su incidencia en el derecho matrimonial canónico: breves reflexiones.

Material incluido en el volumen especial de la revista del Instituto Martín de Azpilcueta, Universidad de Navarra : Ius Canonicum (1999), en honor de Javier Hervada

Condiciones ambientales y diferenciación social en los patrones de movilidad: el caso de las desigualdades de género en el Área Metropolitana de Lisboa

Place determinants and social dimensions interact to produce mobility patterns. The article seeks to measure to what extent the physical and social conditions of the residency place modulate the intensity of mobility particularly in what concerns gender inequalities. To do so, we first present the theoretical framework, which guides our perspective on mobility inequalities and the geographical focus: Lisbon Metropolitan Area (LMA). Secondly, using logistic regression on representative data from a survey to LMA inhabitants we elaborate on the concept of environmental motility and its relationship to various types of inequality. Lastly, we systematize a view on accumulated inequalities examining how local environments may increase the mobilities gender gap.info:eu-repo/semantics/publishedVersio

Surfactant effect in heteroepitaxial growth. The Pb - Co/Cu(111) case

A MonteCarlo simulations study has been performed in order to study the effect of Pb as surfactant on the initial growth stage of Co/Cu(111). The main characteristics of Co growing over Cu(111) face, i.e. the decorated double layer steps, the multiple layer islands and the pools of vacancies, disappear with the pre-evaporation of a Pb monolayer. Through MC simulations, a full picture of these complex processes is obtained. Co quickly diffuses through the Pb monolayer exchanging place with Cu atoms at the substrate. The exchange process diffusion inhibits the formation of pure Co islands, reducing the surface stress and then the formation of multilayer islands and the pools of vacancies. On the other hand, the random exchange also suppress the nucleation preferential sites generated by Co atoms at Cu steps, responsible of the step decoration.Comment: 4 pages, latex, 2 figures embedded in the tex