Botanical origin of honey from south of Caldén district (Argentina)

We performed palynological analysis of 75 honey samples from the south of Caldén district, which is the part of the phytogeographical province del Espinal. Prosopis caldenia, "caldén" (Fabaceae) is the dominant arboreal species in this region. 79 pollen types that belong to 36 plant families were identified. Honeydew elements are absent or present in negligible amounts. Native flora is intensely utilized. Main nectar sources that characterize monofloral honey samples, are these natives Condalia microphylla (Rhamnaceae), Prosopis sp. and Vicia sp. (Fabaceae), Larrea divaricata (Zygophyllaceae) and Brassicaceae, which are foreign to the area. The pollen from these plants along with the pollen of Trichocline sp. (Asteraceae) and Prosopidastrum globosum (Fabaceae), Schinus fasciculatus (Anacardiaceae), Astereae and Lycium sp. (Solanaceae), characterize honey from Caldén.Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plat

Botanical origin of honey from south of Caldén district (Argentina)

We performed palynological analysis of 75 honey samples from the south of Caldén district, which is the part of the phytogeographical province del Espinal. Prosopis caldenia, "caldén" (Fabaceae) is the dominant arboreal species in this region. 79 pollen types that belong to 36 plant families were identified. Honeydew elements are absent or present in negligible amounts. Native flora is intensely utilized. Main nectar sources that characterize monofloral honey samples, are these natives Condalia microphylla (Rhamnaceae), Prosopis sp. and Vicia sp. (Fabaceae), Larrea divaricata (Zygophyllaceae) and Brassicaceae, which are foreign to the area. The pollen from these plants along with the pollen of Trichocline sp. (Asteraceae) and Prosopidastrum globosum (Fabaceae), Schinus fasciculatus (Anacardiaceae), Astereae and Lycium sp. (Solanaceae), characterize honey from Caldén.Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plat

Special symplectic Lie groups and hypersymplectic Lie groups

A special symplectic Lie group is a triple $(G,\omega,\nabla)$ such that $G$ is a finite-dimensional real Lie group and $\omega$ is a left invariant symplectic form on $G$ which is parallel with respect to a left invariant affine structure $\nabla$. In this paper starting from a special symplectic Lie group we show how to ``deform" the standard Lie group structure on the (co)tangent bundle through the left invariant affine structure $\nabla$ such that the resulting Lie group admits families of left invariant hypersymplectic structures and thus becomes a hypersymplectic Lie group. We consider the affine cotangent extension problem and then introduce notions of post-affine structure and post-left-symmetric algebra which is the underlying algebraic structure of a special symplectic Lie algebra. Furthermore, we give a kind of double extensions of special symplectic Lie groups in terms of post-left-symmetric algebras.Comment: 32 page

La Ingeniería Divertida: Gravity Challenge.

La competición se utiliza en muchos entornos educativos, especialmente en el ámbito anglosajón, como medio para contribuir al desarrollo de las habilidades de los alumnos, aspecto este que se encuentra íntimamente ligado a la adquisición de determinadas competencias profesionales. En el sector de la ingeniería y arquitectura resulta de gran importancia y por ello, la Universidad Politécnica de Madrid ha organizado durante el curso 2006‐07 un conjunto de competiciones de estudiantes muy diversas. Una de estas competiciones es la denominada GRAVITY CHALLENGE, en la que los equipos participantes se enfrentaban al reto de lanzar un huevo desde una altura de 15 metros y conseguir que aterrice en el suelo sin romperse. Los equipos ganadores serían aquellos que lograsen este objetivo de la forma más creativa. En este trabajo se describe el procedimiento seguido para la organización de esta competición en la que participaron 27 equipos de distintas universidades. También se presentan los resultados y se hace una reflexión sobre los objetivos formativos que consideramos alcanzados

On paraquaternionic submersions between paraquaternionic K\"ahler manifolds

In this paper we deal with some properties of a class of semi-Riemannian submersions between manifolds endowed with paraquaternionic structures, proving a result of non-existence of paraquaternionic submersions between paraquaternionic K\"ahler non locally hyper paraK\"ahler manifolds. Then we examine, as an example, the canonical projection of the tangent bundle, endowed with the Sasaki metric, of an almost paraquaternionic Hermitian manifold.Comment: 13 pages, no figure

Weak localization and spin splitting in inversion layers on p-type InAs

We report on the magnetoconductivity of quasi two-dimensional electron systems in inversion layers on p-type InAs single crystals. In low magnetic fields pronounced features of weak localization and antilocalization are observed. They are almost perfectly described by the theory of Iordanskii, Lyanda-Geller and Pikus. This allows us to determine the spin splitting and the Rashba parameter of the ground electric subband as a function of the electron density.Comment: Accepted for publication in Phys. Rev. B, 4 page