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

Theory of a Single Magnetic Impurity on a Thin Metal Film in Proximity to a Superconductor

We argue that the formation of Yu-Shiba-Rusinov excitations in proximitized thin films is largely mediated by a type of Andreev-bound state named after de Gennes and Saint James. This is shown by studying an experimentally motivated model and computing the overlap of the wave functions of these two subgap states. We find the overlap stays close to unity even as the system moves away from weak coupling across the parity-changing quantum phase transition. Based on this observation, we introduce a single-site model of the bound state coupled to a quantum spin. The adequacy of this description is assessed by reintroducing the coupling to the continuum as a weak perturbation and studying its scaling flow using Anderson's poor man's scaling.Comment: 12 pages, 3 figure

Metabolic channeling of phe for lignin biosynthesis in maritime pine

Phenylalanine (Phe) is the main precursor of phenylpropanoids biosynthesis in plants. This vast family of Phe-derived compounds can represent more than 30% of captured photosynthetic carbon, playing essential roles in plants such as cell wall components, defense molecules, pigments and flavors. In addition to its physiological importance, phenylpropanoids and particularly lignin, a component of wood, are targets in plant biotechnology. The arogenate pathway has been proposed as the main pathway for Phe biosynthesis in plants (Maeda et al., 2010). The final step in Phe biosynthesis, catalyzed by the enzyme arogenate dehydratase (ADT), has been considered as a key regulatory point in Phe biosynthesis, due to its key branch position in the pathway, the multiple isoenzymes identified in plants and the existence of a feedback inhibition mechanism by Phe. So far, the regulatory mechanisms underlying ADT genes expression have been poorly characterized, although a strong regulation of the Phe metabolic flux should be expected depending on its alternative use for protein biosynthesis versus phenylpropanoid biosynthesis. This second fate involves a massive carbon flux compared to the first one. Here we report our current research activities in the transcriptional regulation of ADT genes by MYB transcription factors in Pinus pinaster. The conifers channels massive amounts of photosynthetic carbon for phenylpropanoid biosynthesis during wood formation. We have identified the complete ADT gene family in maritime pine (El-Azaz et al., 2016) and a set of ADT isoforms specifically related with the lignification process. The potential control of transcription factors previously reported as key regulators in pine wood formation (Craven-Bartle et al., 2013) will be presented.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Nitrogen metabolism in forest trees

NITROGEN METABOLISM IN FOREST TREES Francisco Cánovas, Concepción Ávila, Fernando N de la Torre, Rafael Cañas, Belén Pascual. Universidad de Málaga Email:[email protected] Forests are essential components of the ecosystems covering approximately one-third of the Earth’s land area and playing a fundamental role in the regulation of terrestrial carbon sinks. Forest trees are also of significant economic importance, as they are used for timber and paper production worldwide. A sustainable management of forest resources is needed to preserve natural forest and to meet the increasing international demands in the production of wood and the other forest-derived products. New advances and developments in biotechnology will contribute to accelerate the domestication of important traits for forest productivity. It is critical to identify the fundamental constraints on forest productivity to addressing these constraints with modern genomic tools. Nitrogen availability extremely low in forest ecosystems, and consequently, forest trees have evolved adaptive mechanism and biotic interactions to guarantee the strict economy of this essential nutrient. Nitrogen assimilation and recycling play a key role in the tree growth and biomass production and we firmly believe that knowledge on nitrogen metabolism will lead to approaches aimed at increasing forest productivity. In our laboratory, we are interested in studying nitrogen metabolism and its regulation the conifer maritime pine (Pinus pinaster Aiton), a forest tree species of great economic and ecological importance in the Mediterranean area and relevant model for conifer genomic research in Europe. Current research efforts are focused on improving the understanding of the response of conifer trees to ammonium availability and the transcriptional control of ammonium assimilation into amino acids. An overview and update of our research programme will be presented and discussed. Research supported by Spanish Ministry of Economy and Competitiveness and Junta de Andalucía (Grants BIO2012-33797, PLE2009-016 and research group BIO-114).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Dermocystidiosis induced by the parasite Dermocystidium sp. in the Paracheirodon axelrodi

The Rio Negro floodplain (tributary of the Amazon River) is a natural habitat of the cardinal tetra Paracheirodon axelrodi. In home aquaria, this species has high vulnerability to superficial infetions and is affected by the protist Dermocystidium. Protist cysts were located in the dermis causing lesions reaching in the epidermis. We observed that a few weeks after the introduction of new wild ornamental fish (mostly Hemigrammus sp. or Hyphessobrycon sp.) into established home aquaria, the cardinal tetra fish became infected, suggesting that the new fish could have acted as carriers.Fil: Plaul, Silvia Elena. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Andres Laube, P. F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Montes, Martin Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Topa, Pascual Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Martorelli, Sergio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Barbeito, Claudio Gustavo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentin