48 research outputs found
Symplectically aspherical manifolds with nontrivial π2 and with no Kähler metrics.
In a previous paper, the authors show some examples of compact symplectic solvman-ifolds, of dimension six, which are cohomologically KÄahler and they do not admit Kahler
metrics because their fundamental groups cannot be the fundamental group of any compact Kahler manifold. Here we generalize such manifolds to higher dimension and, by using Au-roux symplectic submanifolds [3], we construct four-dimensional symplectically aspherical manifolds with nontrivial ¼2 and with no Kahler metrics
Solvable Lie algebras are not that hypo
We study a type of left-invariant structure on Lie groups, or equivalently on
Lie algebras. We introduce obstructions to the existence of a hypo structure,
namely the 5-dimensional geometry of hypersurfaces in manifolds with holonomy
SU(3). The choice of a splitting g^*=V_1 + V_2, and the vanishing of certain
associated cohomology groups, determine a first obstruction. We also construct
necessary conditions for the existence of a hypo structure with a fixed
almost-contact form. For non-unimodular Lie algebras, we derive an obstruction
to the existence of a hypo structure, with no choice involved. We apply these
methods to classify solvable Lie algebras that admit a hypo structure.Comment: 21 pages; v2: presentation improved, typos corrected, notational
conflicts eliminated. To appear in Transformation Group
Cohomologically Kähler manifolds with no Kähler metrics.
We show some examples of compact symplectic solvmanifolds, of dimension greater than four, which are cohomologically Kähler and do not admit Kähler metric since their fundamental groups cannot be the fundamental group of any compact Kähler manifold. Some of the examples that we study were considered by Benson and Gordon (1990). However, whether such manifolds have Kähler metrics was an
open question. The formality and the hard Lefschetz property are studied for the symplectic submanifolds constructed by Auroux (1997) and some consequences are discussed
Reversión de sedantes agonistas alfa-2-adrenérgicos en el perro
En el presente Artículo de Revisión se aporta una información amplia sobre los productos de LISO más frecuente en la reversión de los efectos sedantes de los agonistas alfa-2-adrenérgicos empleados en el perro: xilacina, medetomidina y romifidina. Se refieren los detalles farmacológicos, dosificación, efectos y aplicaciones de los siguientes productos: yohimbina, 4-aminopiridina, doxapram y atipamezol
Approach to the Spanish continental Neogene synthesis and paleoclimatic interpretation
Integrated studies on Neogene geology have been scarce in Spain, but attemps to stratigraphic and sedimentological analysis of continental Tertiary basins have increased considerably lately. The large extent of Neogene basins in Spain, the good quality of the outcrops and the abundance of fossil provide an excellent basis for this kind of studies
GEICAM Guidelines for the Management of Patients with Breast Cancer During the COVID-19 Pandemic in Spain
Breast cancer (BC) is the most common cancer in women in
Spain. During the COVID-19 pandemic caused by the SARSCoV-2 virus, patients with BC still require timely treatment
and follow-up; however, hospitals are overwhelmed with
infected patients and, if exposed, patients with BC are at
higher risk for infection and serious complications if infected.
Thus, health care providers need to evaluate each BC treatment and in-hospital visit to minimize pandemic-associated
risks while maintaining adequate treatment efficacy. Here we
present a set of guidelines regarding available options for BC
patient management and treatment by BC subtype in the
context of the COVID-19 pandemic. Owing to the lack of evidence about COVID-19 infection, these recommendations
are mainly based on expert opinion, medical organizations’
and societies’ recommendations, and some published evidence. We consider this a useful tool to facilitate medical
decision making in this health crisis situation we are facing
Spatial evolution of an AMD stream in the Iberian Pyrite Belt: process characterization and control factors on the hydrochemistry
This paper presents hydrochemical data of an AMD stream in the Iberian Pyrite Belt, obtained from its source, in the Poderosa Mine Portal, till its confluence at the Odiel River. The main objective is to establish potential interdependent relations between sulfate and metals’ loads and the following physical-chemical variables: pH, electric conductivity (EC), redox potential (EH), and dissolved oxygen (O2). All the parameters show a global increasing tendency since the tunnel’s exit to the confluence at Odiel River. The TDS and EC are two relevant exceptions. They behave similarly, showing a decreasing trend and a strong inflection that describes a minimum immediately after the discharging point. The spatial analysis combined with statistical tools put in evidence the typical AMD processes and the respective physical-chemical implications. Inputs with distinctive hydrochemical signatures impose relevant modifications in the Poderosa creek waters. This indicates low hydrochemical inertia and high vulnerability to external stimulus.Financial support for this research was provided by DGCICYT National Plan, project CGL2010-21268-C02-01 and the Andalusian Autonomous Government Excellence Projects, Project RNM-6570