Temas de derecho de seguros

En la obra del Profesor se encuentran los elementos que manifiestan la existencia de un Tratado del derecho de los seguros: una parte, se dedica a los actores, empresas de seguros, intermediarios de seguros y autoridades de control; otra, al contrato de seguros en general ya las diversas ramas; de la misma forma, otro segmento se aventura en los caminos de las relaciones internacionales y, especialmente, las entabladas en el marco del reaseguro, sin omitir los aspectos procedimentales. Igualmente, se incluye una síntesis concluyente de la obra: pasado, presente y futuro del derecho de los seguros en Colombia.Se reúnen en esta nueva aportación científica de unas de las voces más serias y rigurosas del derecho del seguro colombiano aportes científicos tratados a lo largo de las últimas dos décadas. La hondura intelectual, el rigor científico, el conocimiento de la realidad aseguraticia y su imbricación en el sistema financiero, la extraordinaria y solícita sagacidad jurídica del autor, doctor Venegas Franco, cobran todo su dinamismo en estos quince estudios profundos, rasgadores y reflexivos de quien es uno de los autores más reputados y prolíficos del derecho latinoamericano de los seguros

La privatización y desguace del sistema ferroviario argentino durante el modelo de acumulación neoliberal

En Argentina, a partir de 1976, el sistema industrial y productivo del país sufrió fuertes transformaciones a partir de la implementación del paradigma neoliberal imperante a nivel internacional. Este cambio estructural, implementado de forma gradual, alteró también -conjuntamente a las relaciones de producción- la dinámica social, laboral, educacional e institucional del país, imprimiendo una lógica capitalista a todo el accionar humano. Como parte de ello se dio en este periodo el proceso de concesiones, privatización y cierre de la mayoría de los ramales ferroviarios que poseía el país, modificando hasta nuestros días la concepción de transporte y perjudicando seriamente al colectivo nacional. De las graves consecuencias que esto produjo trata este trabajo.Fil: Pagano, Franco Alejandro. Universidad Nacional de Cuy

On Rules and Parameter Free Systems in Bounded Arithmetic

We present model–theoretic techniques to obtain conservation results for first order bounded arithmetic theories, based on a hierarchical version of the well known notion of an existentially closed model.Ministerio de Educación y Ciencia MTM2005-0865

Existentially Closed Models and Conservation Results in Bounded Arithmetic

We develop model-theoretic techniques to obtain conservation results for first order Bounded Arithmetic theories, based on a hierarchical version of the well-known notion of an existentially closed model. We focus on the classical Buss' theories Si2 and Ti2 and prove that they are ∀Σbi conservative over their inference rule counterparts, and ∃∀Σbi conservative over their parameter-free versions. A similar analysis of the Σbi-replacement scheme is also developed. The proof method is essentially the same for all the schemes we deal with and shows that these conservation results between schemes and inference rules do not depend on the specific combinatorial or arithmetical content of those schemes. We show that similar conservation results can be derived, in a very general setting, for every scheme enjoying some syntactical (or logical) properties common to both the induction and replacement schemes. Hence, previous conservation results for induction and replacement can be also obtained as corollaries of these more general results.Ministerio de Educación y Ciencia MTM2005-08658Junta de Andalucía TIC-13

Effect of the Si/B ratio on the magnetic anisotropy distribution of Fe73.5Si22.52xBxCu1Nb3 „x57,9,16… alloys along nanocrystallization

The effect of the Si/B ratio on the magnetic anisotropy distribution of Fe73.5Si22.52xBxCu1Nb3 (x57,9,16) alloys has been studied. The influence of isochronal annealing on the hysteresis loop of the three studied alloys has been analyzed. They present two minima in coercivity: the first one can be ascribed to structural relaxation, and the second one is related to the averaging of the magnetocrystalline anisotropy, as predicted by the random anisotropy model. The relative importance of both minima changes with Si content: the lower the Si content, the more effective the structural relaxation and the less important the second minimum are. The mean value of the magnetic anisotropy distribution presents a similar behavior, evidencing the growing importance of the magnetoelastic anisotropy for the relaxed amorphous samples as the Si content is increased. From the evolution of the magnetic anisotropy distribution along nanocrystallization and the microstructural information obtained from transmission electron microscopy images, the behavior of the coercivity minima with changes in Si content can be ascribed to a different degree in compensation of magnetoelastic anisotropy due to the contributions of different signs coming from the nanocrystals and the amorphous matrixCICYT. Gobierno Español-MAT95-0961-CO2-0

Envelopes, indicators and conservativeness

A well known theorem proved (independently) by J. Paris and H. Friedman states that BΣn +1 (the fragment of Arithmetic given by the collection scheme restricted to Σn +1‐formulas) is a Πn +2‐conservative extension of IΣn (the fragment given by the induction scheme restricted to Σn ‐formulas). In this paper, as a continuation of our previous work on collection schemes for Δn +1(T )‐formulas (see [4]), we study a general version of this theorem and characterize theories T such that T + BΣn +1 is a Πn +2‐conservative extension of T . We prove that this conservativeness property is equivalent to a model‐theoretic property relating Πn ‐envelopes and Πn ‐indicators for T . The analysis of Σn +1‐collection we develop here is also applied to Σn +1‐induction using Parsons' conservativeness theorem instead of Friedman‐Paris' theorem. As a corollary, our work provides new model‐theoretic proofs of two theorems of R. Kaye, J. Paris and C. Dimitracopoulos (see [8]): BΣn +1 and IΣn +1 are Σn +3‐conservative extensions of their parameter free versions, BΣ–n +1 and IΣ–n +1.Junta de Andalucía TIC-13

Fragments of Arithmetic and true sentences

By a theorem of R. Kaye, J. Paris and C. Dimitracopoulos, the class of the ¦n+1–sentences true in the standard model is the only (up to deductive equivalence) consistent ¦n+1–theory which extends the scheme of induction for parameter free ¦n+1–formulas. Motivated by this result, we present a systematic study of extensions of bounded quantifier complexity of fragments of first–order Peano Arithmetic. Here, we improve that result and show that this property describes a general phenomenon valid for parameter free schemes. As a consequence, we obtain results on the quantifier complexity, (non)finite axiomatizability and relative strength of schemes for ¢n+1–formulas.Junta de Andalucía TIC-13

On the quantifier complexity of Δ n+1 (T)– induction

In this paper we continue the study of the theories IΔ n+1 (T), initiated in [7]. We focus on the quantifier complexity of these fragments and theirs (non)finite axiomatization. A characterization is obtained for the class of theories such that IΔ n+1 (T) is Π n+2 –axiomatizable. In particular, IΔ n+1 (IΔ n+1 ) gives an axiomatization of Th Π n+2 (IΔ n+1 ) and is not finitely axiomatizable. This fact relates the fragment IΔ n+1 (IΔ n+1 ) to induction rule for Δ n+1 –formulas. Our arguments, involving a construction due to R. Kaye (see [9]), provide proofs of Parsons’ conservativeness theorem (see [16]) and (a weak version) of a result of L.D. Beklemishev on unnested applications of induction rules for Π n+2 and Δ n+1 formulas (see [2]).Ministerio de Educación y Cultura DGES PB96-134

Provably Total Primitive Recursive Functions: Theories with Induction

A natural example of a function algebra is R (T), the class of provably total computable functions (p.t.c.f.) of a theory T in the language of first order Arithmetic. In this paper a simple characterization of that kind of function algebras is obtained. This provides a useful tool for studying the class of primitive recursive functions in R (T). We prove that this is the class of p.t.c.f. of the theory axiomatized by the induction scheme restricted to (parameter free) Δ1(T)–formulas (i.e. Σ1–formulas which are equivalent in T to Π1–formulas). Moreover, if T is a sound theory and proves that exponentiation is a total function, we characterize the class of primitive recursive functions in R (T) as a function algebra described in terms of bounded recursion (and composition). Extensions of this result are related to open problems on complexity classes. We also discuss an application to the problem on the equivalence between (parameter free) Σ1–collection and (uniform) Δ1–induction schemes in Arithmetic. The proofs lean upon axiomatization and conservativeness properties of the scheme of Δ1(T)–induction and its parameter free version