Arabidopsis thaliana bZIP44: a transcription factor affecting seed germination and expression of the mannanase-encoding gene AtMAN7.

Endo-β-mannanases (MAN; EC. 3.2.1.78) catalyze the cleavage of β1[RIGHTWARDS ARROW]4 bonds in mannan polymers and have been associated with the process of weakening the tissues surrounding the embryo during seed germination. In germinating Arabidopsis thaliana seeds, the most highly expressed MAN gene is AtMAN7 and its transcripts are restricted to the micropylar endosperm and to the radicle tip just before radicle emergence. Mutants with a T-DNA insertion in AtMAN7 have a slower germination than the wild type. To gain insight into the transcriptional regulation of the AtMAN7 gene, a bioinformatic search for conserved non-coding cis-elements (phylogenetic shadowing) within the Brassicaceae MAN7 gene promoters has been done, and these conserved motifs have been used as bait to look for their interacting transcription factors (TFs), using as a prey an arrayed yeast library from A. thaliana. The basic-leucine zipper TF AtbZIP44, but not the closely related AtbZIP11, has thus been identified and its transcriptional activation upon AtMAN7 has been validated at the molecular level. In the knock-out lines of AtbZIP44, not only is the expression of the AtMAN7 gene drastically reduced, but these mutants have a significantly slower germination than the wild type, being affected in the two phases of the germination process, both in the rupture of the seed coat and in the breakage of the micropylar endosperm cell walls. In the over-expression lines the opposite phenotype is observed.

Functional and expression analysis of the metal-inducible dmeRF system from Rhizobium legumionosarum bv. viciae

A gene encoding a homolog to the cation diffusion facilitator protein DmeF from Cupriavidus metallidurans has been identified in the genome of Rhizobium leguminosarum UPM791. The R. leguminosarum dmeF gene is located downstream of an open reading frame (designated dmeR) encoding a protein homologous to the nickel- and cobalt-responsive transcriptional regulator RcnR from Escherichia coli. Analysis of gene expression showed that the R. leguminosarum dmeRF genes are organized as a transcriptional unit whose expression is strongly induced by nickel and cobalt ions, likely by alleviating the repressor activity of DmeR on dmeRF transcription. An R. leguminosarum dmeRF mutant strain displayed increased sensitivity to Co(II) and Ni(II), whereas no alterations of its resistance to Cd(II), Cu(II), or Zn(II) were observed. A decrease of symbiotic performance was observed when pea plants inoculated with an R. leguminosarum dmeRF deletion mutant strain were grown in the presence of high concentrations of nickel and cobalt. The same mutant induced significantly lower activity levels of NiFe hydrogenase in microaerobic cultures. These results indicate that the R. leguminosarum DmeRF system is a metal-responsive efflux mechanism acting as a key element for metal homeostasis in R. leguminosarum under free-living and symbiotic conditions. The presence of similar dmeRF gene clusters in other Rhizobiaceae suggests that the dmeRF system is a conserved mechanism for metal tolerance in legume endosymbiotic bacteria.

The family of DOF transcription factors in Brachypodium distachyon: phylogenetic comparison with rice and barley DOFs and expression profiling

ABSTRACT: Transcription factors (TFs) are proteins that have played a central role both in evolution and in domestication, and are major regulators of development in living organisms. Plant genome sequences reveal that approximately 7% of all genes encode putative TFs. The DOF (DNA binding with One Finger) TF family has been associated with vital processes exclusive to higher plants and to their close ancestors (algae, mosses and ferns). These are seed maturation and germination, light-mediated regulation, phytohormone and plant responses to biotic and abiotic stresses, etc. In Hordeum vulgare and Oryza sativa, 26 and 30 different Dof genes, respectively, have been annotated. Brachypodium distachyon has been the first Pooideae grass to be sequenced and, due to its genomic, morphological and physiological characteristics, has emerged as the model system for temperate cereals, such as wheat and barley. RESULTS: Through searches in the B. distachyon genome, 27 Dof genes have been identified and a phylogenetic comparison with the Oryza sativa and the Hordeum vulgare DOFs has been performed. To explore the evolutionary relationship among these DOF proteins, a combined phylogenetic tree has been constructed with the Brachypodium DOFs and those from rice and barley. This phylogenetic analysis has classified the DOF proteins into four Major Cluster of Orthologous Groups (MCOGs). Using RT-qPCR analysis the expression profiles of the annotated BdDof genes across four organs (leaves, roots, spikes and seeds) has been investigated. These results have led to a classification of the BdDof genes into two groups, according to their expression levels. The genes highly or preferentially expressed in seeds have been subjected to a more detailed expression analysis (maturation, dry stage and germination). CONCLUSIONS: Comparison of the expression profiles of the Brachypodium Dof genes with the published functions of closely related DOF sequences from the cereal species considered here, deduced from the phylogenetic analysis, indicates that although the expression profile has been conserved in many of the putative orthologs, in some cases duplication followed by subsequent divergence may have occurred (neo-functionalization).

Contribution to integration and coordination mechanisms for mobile distributed services in publish/subscribe networks

Esta tesis doctoral está enmarcada en dos diferentes pero complementarias áreas de investigación: las redes de Publicación/Subscripción y los servicios móviles distribuidos. Con el paso de los años las redes de Publicación/Subscripción han ido ofreciendo el soporte de comunicaciones desacopladas y ligeras que a su vez, han mejorado la distribución de la información en muchos escenarios de aplicación como lo son la ejecución de servicios distribuidos en entornos fijos. Los servicios móviles distribuidos han de ser desplegados en ambientes inalámbricos en donde los dispositivos móviles deben confiar en las mismas características que las redes de Publicación/Subscripción han estado ofreciendo a sus contrapartes fijos. En este contexto, una de las líneas de investigación pendientes consiste en cómo tomar ventaja de estas características, y cómo avanzar hacia nuevas soluciones no existentes con el fin de mejorar la integración entre los dispositivos fijos y móviles, y la ejecución de los servicios móviles distribuidos. En esta tesis doctoral se pretende avanzar en los mecanismos de integración y coordinación de los servicios móviles distribuidos en el contexto de las redes de Publicación/Subscripción. Los objetivos específicos de esta disertación están enfocados en lograr la integración de los sistemas de Publicación/Suscripción fijos y móviles, y la pro-visión de una versión de red de Publicación/Subscripción específica y uniforme que cuente con mecanismos de coordinación que mejoren la ejecución de los servicios móviles distribuidos. Los resultados de esta tesis doctoral están enmarcados en una versión específica de una red de Publicación/Subscripción que integra brokers fijos y móviles, y permite una coordinación totalmente desacoplada y mejorada entre dispositivos móviles que ejecutan fragmentos de servicios. Las contribuciones específicas son las siguientes: una nueva arquitectura de broker móvil que he llamado Rendezvous Mobile broker, un modelo abstracto de servicios móviles distribuidos coordinados sobre una red de Publicación/Subscripción, mejoras en los mecanismos de enrutamiento epidémicos para diseminar eventos de control producidos por fragmentos de servicios, una solución para soportar servicios altamente fragmentados y geográficamente dispersos, y finalmente una solución de interconexión entre dos dominios de red basados en Publicación/Subscripción: una red basada en el protocolo PubSubHubbub y otro en una red basada en el Publish/Subscribe Internet Routing Paradigm (PSIRP). Los experimentos llevados a cabo confirman que la versión específica de red de Pu-blicación/Subscripción propuesta incrementa el rendimiento de la red en términos de tiempo de espera entre nodos finales, permite una coordinación de los servicios móviles distribuidos más resistente a interrupciones y un mejor uso de los recursos de red, y finalmente logra exitosamente, con variaciones mínimas en el rendimiento de las comunicaciones, la interconexión entre estos dominios de Publicación/Subscripción diferentes. ABSTRACT This dissertation is made up of two different but complementary research areas: Publish/Subscribe networks and mobile distributed services. Over the years, Publish/Subscribe networks have been offering the lightweight and decoupled communication characteristics to improve the information distribution in several application domains such as the execution of distributed services. Mobile distributed services are set to be deployed in wireless environments where mobile devices must rely on the same features Publish/Subscribe networks can offer; so one of the pending research directions consists of how to take advantage of these features and further advance to-wards new un-existing solutions that enhance the integration between mobile and fixed systems and the execution of mobile distributed services. This dissertation seeks to advance the integration and coordination mechanisms of mobile distributed services in the context of Publish/Subscribe networks. The specific objectives aim to enable the integration of mobile and fixed Publish/Subscribe systems and provide a uniform and specific version of a Publish/Subscribe network with new coordination mechanisms that improve the execution of mobile distributed services. The results of this dissertation are enclosed in one specific version of a Publish/Subscribe network that integrates mobile and fixed brokers and coordinates the execution of mobile distributed services. These specific contributions are: a new architecture of a mobile broker I called Rendezvous Mobile Broker, an abstract model for coordinating mobile distributed services executions using a Publish/Subscribe net-work, new gossip routing solutions to disseminate events of services, mechanisms to support highly partitioned and geographically dispersed services and finally, an inter-networking solution between two Publish/Subscribe domains: a PubSubHubbub-based network and the Publish/Subscribe Internet Routing Paradigm (PSIRP)-based network. The experimental efforts confirm that the specific version of the Publish/Subscribe proposed in this dissertation improves the performance of the overall network in terms of end-to-end delay, enables a more resilience execution of mobile distributed services, a better usage of the existing network resources, and finally successfully achieves, with minor variations in the network performance, the internetworking between two different Publish/Subscribe domains.

Enhancing K-12 science education through a multi-device web tool to facilitate content integration and e-infrastructure access

An effective K-12 science education is essential to succeed in future phases of the curriculum and the e-Infrastructures for education provide new opportunities to enhance it. This paper presents ViSH Viewer, an innovative web tool to consume educational content which aims to facilitate e-Science infrastructures access through a next generation learning object called "Virtual Excursion". Virtual Excursions provide a new way to explore science in class by taking advantage of e-Infrastructure resources and their integration with other educational contents, resulting in the creation of a reusable, interoperable and granular learning object. In order to better understand how this tool can allow teachers and students a joyful exploration of e-Science, we also present three Virtual Excursion examples. Details about the design, development and the tool itself are explained in this paper as well as the concept, structure and metadata of the new learning object.

Cis-, trans-, transcriptional regulation of the Arabidopsis thaliana gene AtTrxo1 and its response upon germination and to salt

Plants contain several genes encoding thioredoxins (Trxs), small proteins involved in redox regulation of many enzymes in different cell compartments. Among them, mitochondrial Trxo has been described to have a response in plants grown under salinity but there is scarce information about its functional role in abiotic stress or its gene regulation. In this work, the transcriptional regulation of the mitochondrial AtTrxo1 gene has been studied for the first time, by identifying functionally relevant cis- elements in its promoter: two conserved motives were found as positive and one as negative regulators. Using them as baits for the screening of an arrayed yeast library containing Arabidopsis Transcription Factors (TF) ORFs, two TFs were selected that are now being validated at the molecular level. We have also studied the response of T-DNA insertion mutant plants for AtTrxo1 to salt stress. The K.O. AtTrxo1 mutants presented several phenotypic changes including the time required to reach 50% germination under salinity, without affecting the final germination percentage.

Revisión de:Sport facing cultural diversity. Integration and intercultural dialogue in Europe: analysis and practical example, de Wiliam Gasparini y Aurélie Cometti

Con motivo de la celebracio?n en 2008 del An?o Europeo del Dia?logo Intercultural, el Con- sejo de Europa promovio? una serie de encuentros y foros de debate en torno al papel de Europa en la gestio?n de la inmigracio?n, desde sus mu?ltiples dimensiones. Entre ellas, se encuentra el a?mbito deportivo, por su papel socializador como elemento cultural de dia?logo e identidad, aun- que tambie?n como espacio de confrontacio?n y discriminacio?n, que concierne tanto a participantes como espectadores, desde una perspectiva global y local. Con el objetivo de contrastar experien- cias y reflexiones a este respecto, tuvo lugar la primera conferencia europea con el nombre ?De- porte y Diversidad?, celebrada en Estrasburgo y organizada por la Agencia para la Educacio?n a trave?s del Deporte, el Consejo de Europa - a trave?s del EPAS - y la Universidad de Estrasburgo.