Curvature(s) of a light wavefront in a weak gravitational field

The geometry of a light wavefront evolving from a flat wavefront under the action of weak gravity field in the 3-space associated to a post-Newtonian relativistic spacetime, is studied numerically by means of the ray tracing method.Comment: 3 pages, 1 fig, Talk given by JFPS at the 12th Marcel Grossmann conference (Paris, July, 2009), submitted to the Proceeding

Geometry of an accelerated rotating disk

We analyze the geometry of a rotating disk with a tangential acceleration in the framework of the Special Theory of Relativity, using the kinematic linear differential system that verifies the relative position vector of time-like curves in a Fermi reference. A numerical integration of these equations for a generic initial value problem is made up and the results are compared with those obtained in other works.Comment: 10 pages, LaTeX, 2 eps figs; typos corrected, added reference, minor changes; submitte

Transcriptional regulation os phenylalaline biosynthesis and utilization

Conifer trees divert large quantities of carbon into the biosynthesis of phenylpropanoids, particularly to generate lignin, an important constituent of wood. Since phenylalanine is the precursor for phenylpropanoid biosynthesis, the precise regulation of phenylalanine synthesis and utilization should occur simultaneously. This crucial pathway is finely regulated primarily at the transcriptional level. Transcriptome analyses indicate that the transcription factors (TFs) preferentially expressed during wood formation in plants belong to the MYB and NAC families. Craven-Bartle et al. (2013) have shown in conifers that Myb8 is a candidate regulator of key genes in phenylalanine biosynthesis involved in the supply of the phenylpropane carbon skeleton necessary for lignin biosynthesis. This TF is able to bind AC elements present in the promoter regions of these genes to activate transcription. Constitutive overexpression of Myb8 in white spruce increased secondary-wall thickening and led to ectopic lignin deposition (Bomal et al. 2008). In Arabidopsis, the transcriptional network controlling secondary cell wall involves NAC-domain regulators operating upstream Myb transcription factors. Functional orthologues of members of this network described have been identified in poplar and eucalyptus, but in conifers functional evidence had only been obtained for MYBs. We have identified in the P. pinaster genome 37 genes encoding NAC proteins, which 3 NAC proteins could be potential candidates to be involved in vascular development (Pascual et al. 2015). The understanding of the transcriptional regulatory network associated to phenylpropanoids and lignin biosynthesis in conifers is crucial for future applications in tree improvement and sustainable forest management. This work is supported by the projects BIO2012-33797, BIO2015-69285-R and BIO-474 References: Bomal C, et al. (2008) Involvement of Pinus taeda MYB1 and MYB8 in phenylpropanoid metabolism and secondary cell wall biogenesis: a comparative in planta analysis. J Exp Bot. 59: 3925-3939. Craven-Bartle B, et al. (2013) A Myb transcription factor regulates genes of the phenylalanine pathway in maritime pine. Plant J, 74: 755-766. Pascual MB, et al. (2015) The NAC transcription factor family in maritime pine (Pinus pinaster): molecular regulation of two genes involved in stress responses. BMC Plant Biol, 15: 254.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Els residents estrangers a Espanya

Le but de cette note est de présenter une esquisse sur l'évolution et la composition par nationalités des résidents étrangers en Espagne à partir des données facilitées par l'Annuaire Statistique d'Espagne. Dès les années 40 l'évolution des résidents étrangers montre une croissance continue, seulement arretée par de petites oscillations. Cette croissance s'accélère dans les années 80 avec l'augmentation des flux immigratoires vers l'Espagne, Aussi, la présence d'un nombreux collectif d'immigrés indocumentés a obligé de réaliser deux processus de régularisation en 1985-86 et en 1991. La composition par nationalités montre le poids important des européens, spécialement des pays de la CEE, et l'acroissement des immigrés en provenance des pays du Tiers Monde pendant la dernière décennie.The objective of this note, is to offer some indication of the evolution of the nacionality of foreigners residents in Spain. The number of foreign residents has increased constantly since the 1940s, occasionally interrupted by minor fluctuations. However, the rate of increase accelerated rapidly during the 1980s, with the increase in immigration. In fact the influx of a large number of undocumented immigrants made it necessary to undertake regulatory procedures on two occasions (1958-86 and 1991). Europeans, especially from European Community countries, constitute a large percentage of foreign residents, together with Third World nationals who have increased greatly in number over the last ten years.El objetivo de estas líneas es ofrecer un apunte sobre la evolución y la composición por nacionalidades de los residentes extranjeros a partir de los datos facilitados por el Anuario Estadístico de España. Desde los años cuarenta la evolución de los residentes muestra un crecimiento continuo, solamente interrumpido por pequeñas oscilaciones; un crecimiento que se acelera en la década de los ochenta con el aumento de los flujos inmigratorios hacia España. Asimismo, la presencia de un numeroso colectivo de inmigrantes indocumentados ha obligado a llevar a cabo dos procesos de regularización, el 1985-86 y el 1991. La composición por nacionalidades muestra el importante peso del colectivo europeo, especialmente de los paises que hoy conforman la CE, y el incremento que experimentan las nacionalidades pertenecientes a paises del Tercer Mundo durante esta última década.L'objectiu d'aquesta nota és oferir un apunt sobre l'evolució i la composició per nacionalitats dels residents estrangers a partir de les dades facilitades per l'Anuario Estadístico de España. Des dels anys quaranta l'evolució dels residents mostra un creixement continu, només trencat per petites oscil·lacions. Creixement que s'accelera a la dècada dels vuitanta amb l'increment dels fluxos immigratoris cap a Espanya. Així mateix, la presència d'un nombrós col·lectiu d'inmigrants indocumentats ha obligat a portar a terme dos processos de regularització, el 1985-86 i el 1991. La composició per nacionalitats mostra l'important pes del col·lectiu europeu, especialment dels països que avui conformen la CE, i l'increment que experimenten les nacionalitats pertanyents a països del Tercer Món durant aquesta última dècada

Towards truly simultaneous PIXE and RBS analysis of layered objects in cultural heritage

For a long time, RBS and PIXE techniques have been used in the field of cultural heritage. Although the complementarity of both techniques has long been acknowledged, its full potential has not been yet developed due to the lack of general purpose software tools for analysing the data from both techniques in a coherent way. In this work we provide an example of how the recent addition of PIXE to the set of techniques supported by the DataFurnace code can significantly change this situation. We present a case in which a non homogeneous sample (an oxidized metal from a photographic plate -heliography- made by Niepce in 1827) is analysed using RBS and PIXE in a straightforward and powerful way that can only be performed with a code that treats both techniques simultaneously as a part of one single and coherent analysis. The optimization capabilities of DataFurnace, allowed us to obtain the composition profiles for these samples in a very simple way.Comment: 9 pages, 3 figure

Opcions individuals i pautes col·lectives : mobilitat i poblament a Espanya a la segona meitat del segle XX

Aquest és un article que, partint de dades documentals sobre desplaçaments de població a Espanya en la segona meitat del segle XX, es proposa mostrar quines són les característiques generals dels fluxos, quins són els factors que incideixen en la seva configuració i quina estructura adopten. S'hi posa de relleu el pes de la proximitat, però també el d'altres factors, que permeten afirmar que en l'estructura de destinacions i procedències de les migracions existeixen uns camins preferents que presenten una certa continuïtat històrica. Però la mobilitat és el contrapunt a la permanència, i en aquest sentit el treball destaca la força i l'estabilitat de l'assentament de la població espanyola. Les pautes de mobilitat i poblament reflecteixen finalment el complex esdevenir històric de la societat.Éste es un artículo que, partiendo de datos documentales sobre desplazamientos de población en España en la segunda mitad del siglo XX, se propone mostrar cuáles son las características generales de los flujos, cuáles son los factores que inciden en su configuración y qué estructura adoptan. Se pone de relieve el peso de la proximidad, pero también el de otros factores, que permiten afirmar que en la estructura de destinos y procedencias de las migraciones existen unos caminos preferentes que presentan una cierta continuidad histórica. Pero la movilidad es el contrapunto a la permanencia, y en este sentido el trabajo destaca la fuerza y la estabilidad del asentamiento de la población española. Las pautas de movilidad y poblamiento reflejan el complejo acontecer de la sociedad.Il s'agit là d'un article qui, partant des données documentaires au sujet des déplacements de population en Espagne pendant la seconde moitié du XXe siècle, a pour but de montrer quelles sont les caractéristiques générales des flux, quels sont les facteurs qui influencent leur configuration et quelle est la structure qu'ils adoptent. On y met en relief l'importance de la proximité mais aussi celle d'autres facteurs qui permettent d'affirmer que dans la structure des destins et des origines des migrations il existe des chemins préférentiels qui suivent une certaine continuité historique. La mobilité a cependant comme contrepartie la permanence, et c'est dans ce sens que le travail y souligne la force et la stabilité de l'établissement humain en Espagne. Les modèles de mobilité et de population reflètent le devenir complexe de la société.This is an article that, starting from documentary evidence on population dispersal in Spain in the second half of the 20th century, aims at illustrating the general characteristics of the population flows, the factors that influence their configuration and the structure that they take on. It highlights the weight of proximity, but also draws attention to other factors, allowing it to be stated that in the structure of migratory destinations and starting points, some given routes are preferred, and these present a certain historical continuity. But mobility is a pounterpoint to permanence, and in this sense, the article underlines the strength and stability of settlement in the Spanish population. The criteria of mobility and settlement reflect the complex occurrences of society

Exploiting transmission spatial diversity in frequency selective systems with feedback channel

In this paper we address the design of a multiple transmit antenna system in which the Channel State Information (CSI) at the transmitter is not perfect. Two different approaches are analyzed one based on the Minimization of the Mean Square Error (MMSEj and the other based on the application of the Maximum Likelihood Sequence Estimation (MLSE). In both cases a Bayesian criterion is used in order to take into account the error between the CSI and the real channel. Finally, some simulation results and conclusions are provided, showing which is the gain of these approaches when the error between the CSI and the real channel is either Gaussian or uniform, where this last case corresponds to a quantization of the channel time response in order to transmit the CSI through a feedback channel from the receiver to the transmitter.Postprint (published version