Coloquio de La Habana: "Encuentro sobre la deuda externa de América Latina y el Caribe". México

Declaración de principios firmada por los participantes mexicanos al encuentro latinoamericano y del caribe, y que incluye miembros de partidos políticos, dirigentes sindicales y campesinos, profesores e investigadores universitarios, logias masónicas, religiosos, representantes estudiantiles, periodistas, organizaciones femeninas y escritores

Multiparameter quantum groups, bosonizations and cocycle deformations

The multiparameter quantized enveloping algebras Uq(gA) constructed by Pei, Hu and Rosso [Quantum affine algebras, extended affine Lie algebras, and their applications, 145–171, Amer. Math. Soc., Providence, 2010] are presented as the pointed Hopf algebras Ue(Dred, `) defined by Andruskiewitsch and Schneider [Ann. of Math. (2) 171 (2010), 375–417]. The result is applied to show that under a certain assumption Uq(gA) depends, up to cocycle deformation, on only one parameter in each connected component of the associated Dynkin diagram. In the special case that gA is simple, this was already shown by Pei, Hu and Rosso in an alternative way.Facultad de Ciencias ExactasConsejo Nacional de Investigaciones Científicas y Técnica

Quantum subgroups of GLα,β(n)

AbstractLet α,β∈C∖{0} and ℓ∈N be odd with ℓ⩾3. We determine all Hopf algebra quotients of the quantized coordinate algebra Oα,β(GLn) when α−1β is a primitive ℓ-th root of unity and α, β satisfy certain mild conditions, and we characterize all finite-dimensional quotients when α−1β is not a root of unity. As a byproduct we find a new family of non-semisimple and non-pointed Hopf algebras with non-pointed duals which are quotients of Oα,β(GLn)

Techniques for classifying Hopf algebras and applications to dimension p3

Classifying Hopf algebras of a given finite dimension n over C is a challenging problem. If n is p, p^2, 2p, or 2p^2 with p prime, the classification is complete. If n = p^3, the semisimple and the pointed Hopf algebras are classified and much progress on the remaining cases was made by the second author but the general classification is still open. Here we outline some results and techniques which have been useful in approaching this problem and add a few new ones. We give some further results on Hopf algebras of dimension p^3 and finish the classification for dimension 27.Fil: Beattie, M.. Mount Allison University; CanadáFil: García, Gastón Andrés. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigación y Estudios de Matemática de Córdoba(p); Argentin

Forest connectivity restoration through reforestation: an integrated methodology for prioritizing agricultural lands and selecting reforestation species

Forest connectivity restoration is a major goal in natural resource planning. Given the high amount of abandoned cultivated lands, setting efficient methods for the reforestation of agricultural lands offers a good opportunity to face this issue. However, reforestations must be carefully planned, which poses two main challenges. In first place, to determine those agricultural lands that, once reforested, would meet more effectively the planning goals. As a further step, in order to grant the success of the activity, it is fairly advisable to select those tree species that are more adapted to each particular environment. Here we intend to give response to both requirements by proposing a sequential and integrated methodology that has been implemented in two Spanish forest districts, which are formed by several landscape types that were previously defined and characterized. Using the software Conefor Sensinode, a powerful tool for quantifying habitat availability that is based on graph theory concepts, we determined the landscapes where forest planning should have connectivity as a major concern and, afterwards, we detected the agricultural patches that would contribute most to enhance connectivity if they were reforested. The subsequent reforestation species assessment was performed within these priority patches. Using penalized logistic regressions we fitted ecological niche models for the Spanish native tree species. The models were trained with species distribution data from the Spanish Forest Map and used climatic and lithological variables as predictors. Model predictions were used to build ordered lists of suitable species for each priority patch. The lists include dominant and non dominant tree species and allow adding biodiversity goals to the reforestation planning. The result of this combined methodology is a map of agricultural patches that would contribute most to uphold forest connectivity if they were reforested and a list of suitable tree species for each patch ordered by occurrence probability. Therefore the proposed methodology may be useful for suitable and efficient forest planning and landscape designing