213 research outputs found
¿Cuántas clases de verbos de desplazamiento se distinguen en español?
El artículo presenta una propuesta de análisis de la categoría léxica de los verbos de movimiento, en concreto de los que refieren el movimiento del sujeto. Parte de un análisis crítico de algunos de los análisis más citados sobre los mismos: los de Talmy, Aske, Jackendoff Lamiroy, Cifuentes y Llopis, y Morimoto. Todos tienen en común el intento de justificar con pruebas de combinación y de comportamiento sintáctico la distinción entre verbos de desplazamiento y de modo de desplazamiento. Aplicando el mismo tipo de pruebas se propone aquí que no hay motivos suficientes para justificar plenamente tal dicotomía. This article presents an extended typology of a part of the lexical category ‘motion verb’ in Spanish, compared to other well-known interpretations (Talmy, Aske, Jackendoff, Lamiroy, Cifuentes and Llopis, and Morimoto) which apply tests for syntacttic behaviour and / or combination possibilities with PATH-indicators. These data allow us to reflect on some combinatorial characteristics of Spanish verbs, which are not enough to justify a clear-cut categorization in terms of ‘verbs of motion’ vs. ‘verbs of manner of motion’
Direct decompositions of artinian modules related to formations of groups
We survey direct decompositions of artinian modules over group rings into two summands where all the chief factors
of the first are X–central and all the chief factors of the other is
X–eccentric, where X is a certain formation of finite groups
On the contribution of D.I. Zaitsev to the Theory of Infinite Groups
We survey the most outstanding contributions due to D.I. Zaitsev in the Theory of Infinite Groups
Minimal surfaces and particles in 3-manifolds
We use minimal (or CMC) surfaces to describe 3-dimensional hyperbolic,
anti-de Sitter, de Sitter or Minkowski manifolds. We consider whether these
manifolds admit ``nice'' foliations and explicit metrics, and whether the space
of these metrics has a simple description in terms of Teichm\"uller theory. In
the hyperbolic settings both questions have positive answers for a certain
subset of the quasi-Fuchsian manifolds: those containing a closed surface with
principal curvatures at most 1. We show that this subset is parameterized by an
open domain of the cotangent bundle of Teichm\"uller space. These results are
extended to ``quasi-Fuchsian'' manifolds with conical singularities along
infinite lines, known in the physics literature as ``massive, spin-less
particles''.
Things work better for globally hyperbolic anti-de Sitter manifolds: the
parameterization by the cotangent of Teichm\"uller space works for all
manifolds. There is another description of this moduli space as the product two
copies of Teichm\"uller space due to Mess. Using the maximal surface
description, we propose a new parameterization by two copies of Teichm\"uller
space, alternative to that of Mess, and extend all the results to manifolds
with conical singularities along time-like lines. Similar results are obtained
for de Sitter or Minkowski manifolds.
Finally, for all four settings, we show that the symplectic form on the
moduli space of 3-manifolds that comes from parameterization by the cotangent
bundle of Teichm\"uller space is the same as the 3-dimensional gravity one.Comment: 53 pages, no figure. v2: typos corrected and refs adde
Detection of a putative TetR-like gene related to Mycobacterium bovis BCG growth in cholesterol using a gfp-transposon mutagenesis system
In vitro transposition is a powerful genetic tool for identifying mycobacterial virulence genes and studying virulence factors in relation to the host. Transposon shuttle mutagenesis is a method for constructing stable insertions in the genome of different microorganisms including mycobacteria. Using an IS1096 derivative, we have constructed the Tngfp, a transposon containing a promoterless green fluorescent protein (gfp) gene. This transposon was able to transpose randomly in Mycobacterium bovis BCG. Bacteria with a single copy of the gfp gene per chromosome from an M. bovis BCG::Tngfp library were analyzed and cells exhibiting high levels of fluorescence were detected by flow cytometry. Application of this approach allowed for the selection of a mutant, BCG_2177c::Tngfp (BCG-Tn), on the basis of high level of long-standing fluorescence at stationary phase. This BCG-Tn mutant showed some particular phenotypic features compared to the wild type strain, mainly during stationary phase, when cholesterol was used as a sole carbon source, thus supporting the relationships of the targeted gene with the regulation of cholesterol metabolism in this bacteria. This approach showed that Tngfp is a potentially useful tool for studying the involvement of the targeted loci in metabolic pathways of mycobacteria
- …