On the generalized Feng-Rao numbers of numerical semigroups generated by intervals

We give some general results concerning the computation of the generalized Feng-Rao numbers of numerical semigroups. In the case of a numerical semigroup generated by an interval, a formula for the $r^{th}$ Feng-Rao number is obtained.Comment: 23 pages, 6 figure

Nueva localidad de Psilotum nudum (L.) PB.

Two naturalised taxa in the Iberian Peninsula present in west Andalusia. Plabras clave. Hibiscus, Solanum, Andalucía.Key words. Hibiscus, Solamon, Andalusia

On the structure of split Lie color algebras

AbstractThe class of Lie color algebras contains the one of Lie superalgebras and so the one of Lie algebras. In order to begin an approach to the structure of arbitrary Lie color algebras, (with no restrictions neither on the dimension nor on the base field), we introduce the class of split Lie color algebras as the natural extension of the classes of split Lie algebras and split Lie superalgebras. By developing techniques of connections of roots for this kind of algebra, we show that any such algebra L is of the form L=U+∑jIj with U a subspace of the abelian (graded) subalgebra H and eachx Ij a well described (graded) ideal of L satisfying [Ij,Ik]=0 if j≠k. Under certain conditions, the simplicity of L is characterized and it is shown that L is the direct sum of the family of its minimal (graded) ideals, each one being a simple split Lie color algebra

Carbon and oxygen abundances from recombination lines in low-metallicity star-forming galaxies. Implications for chemical evolution

We present deep echelle spectrophotometry of the brightest emission-line knots of the star-forming galaxies He 2-10, Mkn 1271, NGC 3125, NGC 5408, POX 4, SDSS J1253-0312, Tol 1457-262, Tol 1924-416 and the HII region Hubble V in the Local Group dwarf irregular galaxy NGC 6822. The data have been taken with the Very Large Telescope Ultraviolet-Visual Echelle Spectrograph in the 3100-10420 {\AA} range. We determine electron densities and temperatures of the ionized gas from several emission-line intensity ratios for all the objects. We derive the ionic abundances of C$^{2+}$ and/or O$^{2+}$ from faint pure recombination lines (RLs) in several of the objects, permitting to derive their C/H and C/O ratios. We have explored the chemical evolution at low metallicities analysing the C/O vs. O/H, C/O vs. N/O and C/N vs. O/H relations for Galactic and extragalactic HII regions and comparing with results for halo stars and DLAs. We find that HII regions in star-forming dwarf galaxies occupy a different locus in the C/O vs. O/H diagram than those belonging to the inner discs of spiral galaxies, indicating their different chemical evolution histories, and that the bulk of C in the most metal-poor extragalactic HII regions should have the same origin than in halo stars. The comparison between the C/O ratios in HII regions and in stars of the Galactic thick and thin discs seems to give arguments to support the merging scenario for the origin of the Galactic thick disc. Finally, we find an apparent coupling between C and N enrichment at the usual metallicities determined for HII regions and that this coupling breaks in very low-metallicity objects.Comment: 27 pages, 12 figures, Accepted for publication in Monthly Notices of the Royal Astronomical Societ

Factorizing operators on Banach function spaces through spaces of multiplication operators

In order to extend the theory of optimal domains for continuous operators on a Banach function space X(μ) over a finite measure μ, we consider operators T satisfying other type of inequalities than the one given by the continuity which occur in several well-known factorization theorems (for instance, Pisier Factorization Theorem through Lorentz spaces, pth-power factorable operators . . . ). We prove that such a T factorizes through a space of multiplication operators which can be understood in a certain sense as the optimal domain for T . Our extended optimal domain technique does not need necessarily the equivalence between μ and the measure defined by the operator T and, by using δ-rings, μ is allowed to be infinite. Classical and new examples and applications of our results are also given, including some new results on the Hardy operator and a factorization theorem through Hilbert spaces.Generalitat Valenciana TSGD-07Ministerio de Educación y Ciencia MTM2006-13000-C03-0

The nitric oxide response in plant-associated endosymbiotic bacteria

Nitric oxide (NO) is a gaseous signalling molecule which becomes very toxic due to its ability to react with multiple cellular targets in biological systems. Bacterial cells protect against NO through the expression of enzymes that detoxify this molecule by oxidizing it to nitrate or reducing it to nitrous oxide or ammonia. These enzymes are haemoglobins, c-type nitric oxide reductase, flavorubredoxins and the cytochrome c respiratory nitrite reductase. Expression of the genes encoding these enzymes is controlled by NO-sensitive regulatory proteins. The production of NO in rhizobia–legume symbiosis has been demonstrated recently. In functioning nodules, NO acts as a potent inhibitor of nitrogenase enzymes. These observations have led to the question of how rhizobia overcome the toxicity of NO. Several studies on the NO response have been undertaken in two non-dentrifying rhizobial species, Sinorhizobium meliloti and Rhizobium etli, and in a denitrifying species, Bradyrhizobium japonicum. In the present mini-review, current knowledge of the NO response in those legume-associated endosymbiotic bacteria is summarized

Factores contextuales que influyen en el desempeño docente

En este trabajo presentamos una revisión conceptual acerca de los factores contextuales que influyen en el desempeño docente. El objetivo del trabajo es analizar la influencia que estos factores tienen en la docencia y, en consecuencia, la necesidad de considerarlos para el diseño de planes de evaluación de profesorado. Se identifican cuatro niveles de contextualización de la docencia: el salón de clases, el contexto institucional (que integra el centro escolar y el sistema educativo), y dos contextos sociales (el inmediato o cercano: población a la que atiende el profesorado y el centro escolar; y el mediato o lejano: las características poblacionales ¿socioeconómicas y culturales- de la región en que se sitúa el centro escolar ¿distrito-). Se analizan las posibles influencias de cada contexto, y el tipo de indicadores que podríamos identificar para tener en cuenta la influencia del contexto en el desempeño docente. La finalidad es aportar bases para diseñar evaluaciones válidas del profesorado, en las que se asegure la justicia, la equidad y la utilidad

Reflexiones en torno al contexto de la docencia universitaria desde un concepto de Cohesión Social : intervención educativa y evaluación = Reflections on the context of university teaching from a concept of Social Cohesion : educational intervention and evaluation

En este trabajo se realiza una revisión de las áreas de intervención que podrían abordar las instituciones de Educación Superior, en un marco de trabajo cuyo propósito es el desarrollo de la Cohesión Social. Se unen, pues, dos conceptos que integran la acción docente: la planificación universitaria y su intervención. Este marco de trabajo permite identificar las áreas de orientación de los procesos de evaluación que podrían integrarse, ofreciendo una concepción del contexto del trabajo del docente universitario. De este modo, se revisa la definición de Cohesión Social que aporta el Consejo de Europa en 2005. En ella, se analizan posibles dimensiones que se toman como referencia para identificar procesos de intervención y necesidades de desarrollo de planes de evaluación. Se trata, pues, de un planteamiento sistémico que integra de manera holista la intervención con su evaluación. In this paper, we revise the areas of intervention that could approach the institutions of Higher Education, in a framework whose aim is the development of Social Cohesion. Two concepts that integrate the teaching action unite: the university planning and its intervention. Offering a conception of the university teaching context, this framework allows us to identify the areas of orientation of the evaluation processes that could be integrated. In this way, we revise the definition of Social Cohesion, which the Council of Europe provides in 2005. In this definition, some possible dimensions are analyzed, which are taken as reference to identify the intervention processes and the necessity of development of evaluation plans. Therefore, it's considered as a systemic proposal that integrates holistically the intervention with its evaluation