Families of Riemann Surfaces, Uniformization and Arithmeticity

A consequence of the results of Bers and Griffiths on the uniformization of complex algebraic varieties is that the universal cover of a family of Riemann surfaces, with base and fibers of finite hyperbolic type, is a contractible 2-dimensional domain that can be realized as the graph of a holomorphic motion of the unit disk. In this paper we determine which holomorphic motions give rise to these uniformizing domains and characterize which among them correspond to arithmetic families (i.e. families defined over number fields). Then we apply these results to characterize the arithmeticity of complex surfaces of general type in terms of the biholomorphism class of the 2-dimensional domains that arise as universal covers of their Zariski open subsets. For the important class of Kodaira fibrations this criterion implies that arithmeticity can be read off from the universal cover. All this is very much in contrast with the corresponding situation in complex dimension one, where the universal cover is always the unit disk

Rotating and counterrotating relativistic thin disks as sources of stationary electrovacuum spacetimes

A detailed study is presented of the counterrotating model (CRM) for electrovacuum stationary axially symmetric relativistic thin disks of infinite extension without radial stress, in the case when the eigenvalues of the energy-momentum tensor of the disk are real quantities, so that there is not heat flow. We find a general constraint over the counterrotating tangential velocities needed to cast the surface energy-momentum tensor of the disk as the superposition of two counterrotating charged dust fluids. We then show that, in some cases, this constraint can be satisfied if we take the two counterrotating tangential velocities as equal and opposite or by taking the two counterrotating streams as circulating along electro-geodesics. However, we show that, in general, it is not possible to take the two counterrotating fluids as circulating along electro-geodesics nor take the two counterrotating tangential velocities as equal and opposite. A simple family of models of counterrotating charged disks based on the Kerr-Newman solution are considered where we obtain some disks with a CRM well behaved. We also show that the disks constructed from the Kerr-Newman solution can be interpreted, for all the values of parameters, as a matter distribution with currents and purely azimuthal pressure without heat flow. The models are constructed using the well-known "displace, cut and reflect" method extended to solutions of vacuum Einstein-Maxwell equations. We obtain, in all the cases, counterrotating Kerr-Newman disks that are in agreement with all the energy conditions.Comment: 22 pages, 7 figures, Late

Information systems offshore outsourcing: a descriptive analysis

Purpose - The present paper has as its aim to deepen in the study of Information Systems Offshore Outsourcing, proposing three essential steps to make this decision: weighing up the advantages and risks of Offshore Outsourcing; analysing the taxonomy of this phenomenon; and determining its current geography. Design/Methodology/Approach - With that objective in mind, it was decided to base the research work on the literature about this topic and the review of reports and statistics coming from different sources (consultants, the press, public institutions, etc.). Findings - Offshore Outsourcing has grown vertiginously in recent years. Its advantages exceed even those of onshore outsourcing, though it also involves greater risks derived from the (cultural and physical) distance existing between customer and provider. Various types of services and customer-provider relationships hide under the umbrella of Offshore Outsourcing; i.e. it is not a homogeneous phenomenon. The main Offshore Outsourcing customers can be found in the USA and Europe, mainly in the UK but also in other countries such as Germany and France. As for provider firms, most of them are located in Asia −outstandingly in India but also in China and Russia. At present, there are important providers scattered in other continents as well. Originality/Value - The conclusions suggest that the range of potential Offshore Outsourcing destinations must be widened and that the search for a provider cannot be based exclusively on cost savings; other considerations such as quality, security and proximity of the provider must also be taken into consideration. That is precisely the reason why the study of new countries like Spain as Offshore Outsourcing destinations is proposed

Firm Failure and Relationship Lending:New Evidence from Small Businesses

We study the effect of relationship lending on small firms failure probability using a uniquely rich data set comprised of information on individual loans of a large number of small firms in Colombia. We control for firm-specific variables and find that small firms involved in long-term liaisons with commercial banks have a significantly lower probability of becoming bankrupt than otherwise identical firms not involved in a long-term credit relationship. We also find that small firms with multiple banking relationships face a lower failure hazard than otherwise identical firms involved in a unique long-term relationship.Firms, bank relationships, survival analysis. Classification JEL: G20, G21, C40.

Els Planella. Barons de Granera i senyors de Talamanca

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Il nuovo vicerè. Apuntes sobre la entrada y toma de posesión de los virreyes en la Sicilia del siglo XVII

L’arribada d’un virrei a Sicília es convertia en motiu de celebració per al regne. Des que es tenia notícia de la nova designació, els organismes locals de Palerm o de Messina, segons la ciutat on havia de fer l’entrada, posaven els seus esforços a mostrar una imatge majestuosa de l’esdeveniment. Feien construir obeliscs, grades i arquitectures efímeres, que se succeïen al llarg del recorregut cerimonial pel qual havia de passar el nou pro rex. Arran d’això, un acte de tipus legal i jurídic es va anar convertint, especialment durant el segle XVII, en un espectacle en el qual els diversos actors que hi intervenien (l’Església, el virrei, la noblesa i el poble) desenvolupaven un paper molt concret. Tot i que les entrades virregnals a Sicília no van ser tan espectaculars com les dels territoris d’ultramar, reflectien les particularitats del regne i els interessos de les seves elits, i eren especialment simbòliques i úniquesLa llegada de un virrey a Sicilia era motivo de celebración para el reino. Desde que se tenía noticia de la nueva designación, los organismos locales de Palermo o Mesina, según por dónde hiciera su entrada, ponían sus esfuerzos en mostrar una imagen sobrecogedora de la misma. Hacían construir obeliscos, gradas y arquitecturas efímeras que se sucedían a lo largo del recorrido ceremonial por donde pasaría el pro rex. De ese modo, un acto de tipo legal y jurídico fue convirtiéndose, especialmente durante el siglo XVII, en un espectáculo en el que los diversos actores que intervenían (Iglesia, virrey, nobles ypueblo) cumplían un papel muy concreto. A pesar de que las entradas virreinales en Sicilia no fueron tan espectaculares como las de los territorios de ultramar, reflejaban las particularidades propias del reino y de los intereses desus élites, siendo especialmente simbólicas y únicasThe arrival of a new viceroy to Sicily was cause for celebration for the kingdom. When news of a new appointment became known, the local government in Palermo or Messina, depending on which city would be used for the entry, would focus its efforts on showing off the city to its best advantage, constructing obelisks, grandstands and ephemeral architectures along the ceremonial route. In this way, a ceremony of a legal and juridical nature was becoming, especially in the 17th century, a show in which the various actors involved (the church, nobility, the viceroy and the people) played very specific roles. Although viceregal entries in Sicily were not as spectacular as those of the overseas territories, they reflected the character of the kingdom and the interests of its elite, which were particularly symbolic and uniqu

Educational games in english to improve oral expression for eighth grade students at the public school Trece de Abril, La Libertad, province of Santa Elena, school year 2014-2015.

This Graduation Thesis focused on educational games research to improve oral expression for eight grade students at the public school "TRECE DE ABRIL". The general objective is to develop a proposal of how to implement the use of educational games in the classroom to improve oral expression of the English language. This project has been developed on the basis of the socio-educational approach, qualitative and quantitative and it is supported in a experimental field research, correlation, bibliographic research and field work. After carrying out this research it was concluded that educational games were not used at the “TRECE DE ABRIL” School. For this reason, a proposal of didactic games in the classroom is proposed as an alternative