Plate-forme de prototypage et conception pour les systèmes de radio-logicielle

- Cet article présente la plate-forme radio logicielle utilisée dans le projet PALMYRE, élaboré dans le cadre du Contrat de Plan Etat Région (CPER) pour une durée de 5 ans. La plate-forme hétérogène et commune à plusieurs laboratoires bretons va ainsi permettre le développement et l'évaluation de systèmes radioélectriques pour les futures générations. Pour faciliter le portage de multiples applications sur cette plate-forme, une méthodologie de conception est mise en place, offrant ainsi un couplage algorithme-architecture maximal

A dynamic computation method for fast and accurate performance evaluation of multi-core architectures

Early estimation of performance has become necessary to facilitate design of complex multi-core architectures. Performance evaluation based on extensive simulations is time consuming and needs to be improved to allow exploration of different architectures in acceptable time. In this paper, we propose a method that improves the tradeoff between simulation speed and accuracy in performance models of architectures. This method computes during model execution some of the synchronization instants involved in architecture evolution. It allows grouping and abstracting architecture processes and this way significantly reduces the number of simulation events. Experiments show significant benefits from the computation method on the simulation time. Especially, a simulation speed-up by a factor of 4 is achieved in the considered case study, with no loss of accuracy about estimation of processing resource usage. The proposed method has potential to support automatic generation of efficient architecture models

An improved encapsulation protocol for regrowth and conservation of four ornamental species

The encapsulation technology, initially developed for clonal propagation through the production of synthetic seeds with somatic embryos, is currently proposed for use with non-embryogenic explants, such as buds and nodal segments (unipolar propagules). In the present study, the encapsulation procedure and its effect on shoot regeneration were evaluated. Apical buds isolated from shoot cultures of four ornamental species (Photinia × fraseri Dress., Polygala myrtifolia L., Metrosideros excelsa Soland. ex Gaertn., and Rosa) were encapsulated in 3% sodium alginate. Effects of complexation time, sucrose concentration, and storage temperature on the regrowth ability of propagules were assessed. With the appropriate combination of sucrose concentration and polymerization time, the encapsulated explants proved to have a better regrowth (80–100%) after sowing than the naked ones. In addition, medium-term storage of Metrosideros encapsulated explants promoted a high level of regrowth (74%) after 4 months in the dark at 10°C; while polygala beads were preserved up to 8 months regardless of storage temperatures. Potential current applications of encapsulation technology and the future use of beads in vivo conditions are also discussed

A TCR beta-Chain Motif Biases toward Recognition of Human CD1 Proteins

High-throughput TCR sequencing allows interrogation of the human TCR repertoire, potentially connecting TCR sequences to antigenic targets. Unlike the highly polymorphic MHC proteins, monomorphic Ag-presenting molecules such as MR1, CD1d, and CD1b present Ags to T cells with species-wide TCR motifs. CD1b tetramer studies and a survey of the 27 published CD1b-restricted TCRs demonstrated a TCR motif in humans defined by the TCR β-chain variable gene 4-1 (TRBV4-1) region. Unexpectedly, TRBV4-1 was involved in recognition of CD1b regardless of the chemical class of the carried lipid. Crystal structures of two CD1b-specific TRBV4-1+ TCRs show that germline-encoded residues in CDR1 and CDR3 regions of TRBV4-1–encoded sequences interact with each other and consolidate the surface of the TCR. Mutational studies identified a key positively charged residue in TRBV4-1 and a key negatively charged residue in CD1b that is shared with CD1c, which is also recognized by TRBV4-1 TCRs. These data show that one TCR V region can mediate a mechanism of recognition of two related monomorphic Ag-presenting molecules that does not rely on a defined lipid Ag

An improved encapsulation protocol for regrowth and conservation of four ornamental species

The encapsulation technology, initially developed for clonal propagation through the production of synthetic seeds with somatic embryos, is currently proposed for use with non-embryogenic explants, such as buds and nodal segments (unipolar propagules). In the present study, the encapsulation procedure and its effect on shoot regeneration were evaluated. Apical buds isolated from shoot cultures of four ornamental species (Photinia × fraseri Dress., Polygala myrtifolia L., Metrosideros excelsa Soland. ex Gaertn., and Rosa) were encapsulated in 3% sodium alginate. Effects of complexation time, sucrose concentration, and storage temperature on the regrowth ability of propagules were assessed. With the appropriate combination of sucrose concentration and polymerization time, the encapsulated explants proved to have a better regrowth (80–100%) after sowing than the naked ones. In addition, medium-term storage of Metrosideros encapsulated explants promoted a high level of regrowth (74%) after 4 months in the dark at 10°C; while polygala beads were preserved up to 8 months regardless of storage temperatures. Potential current applications of encapsulation technology and the future use of beads in vivo conditions are also discussed

Targeted depletion of RibF, a putative bifunctional FAD synthetase/ flavokinase in Mycobacterium smegmatis using CRISPR interference

Tuberculosis (TB) is the leading killer globally owing to an infectious disease. There is consequently an urgent need to develop novel TB drugs and shorter regimens to treat the causative agent, Mycobacterium tuberculosis, an imperative which demands the identification of new drug targets in essential mycobacterial pathways. To that end, the work presented in this dissertation aimed to functionally characterize ribF, an essential gene in the mycobacterial riboflavin (RF; vitamin B2) biosynthetic pathway. Given the role of RF as a core component of the essential flavin cofactors, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), it was hypothesized that silencing ribF would disrupt the biosynthesis of all flavoproteins, crippling numerous (essential) processes within the organism. Moreover, based on previous observations in Bacillus subtilis, it was predicted that the mycobacterial ribF homolog might play a role in regulating the rib operon (comprising a cluster of RF pathway genes) – either directly by binding to the FMN riboswitch, or indirectly through the production of FMN from RF, in turn enabling riboswitch-mediated repression of downstream genes. CRISPR interference (CRISPRi) technology was used to generate an anhydrotetracycline (ATc)-inducible ribF hypomorph of M. smegmatis, a widely exploited mycobacterial model. Consistent with other organisms, ribF was shown to be essential for in vitro growth of M. smegmatis: CRISPRi-mediated depletion of ribF was bacteriostatic, resulting in a 10-fold growth inhibition in liquid media and corresponding to no reduction (0 log-fold change) in colony forming units (CFU). Moreover, targeted metabolomic analyses revealed that ribF depletion was associated with accumulation of 6,7-Dimethylribityllumazine (DMRL), suggesting that the disruption of RibF function blocked conversion of RF to the essential cofactors, FMN and FAD, in turn inhibiting cell growth. Notably, the lethality of ribF depletion could not be complemented chemically by exogenous supplementation of growth media with RF, FMN or FAD. Downregulation of ribF also caused enhanced susceptibility to the known cell wall-targeting agent, vancomycin, but not to the putative RibF domain inhibitor, thonzonium bromide, suggesting an alternative mechanism of action or impaired bacillary permeation. In summary, these data support the inferred essentiality of ribF in mycobacteria, in turn supporting future work which aims to target this enzyme for new TB drug discovery

Estudio y optimización del proceso de propagación in vitro de Limonium sinuatum

[SPA] Limonium sinuatum es una especie de la familia de las plumbagináceas. Esta especie es muy apreciada porque tiene buen mercado tanto para flor seca como para flor en fresco. Unos de los problemas que presenta esta especie es la obtención masiva de plantas. La propagación convencional de muchos cultivares de Limonium se hace por semilla o por esquejes, de manera que la obtención de la planta lleva entre 6 y 8 meses, con un rendimiento limitado (20-30 %) y en muchos casos las plantas obtenidas no son homogéneas. Como alternativa se suele utilizar la propagación in vitro o micropropagación, que se realiza en laboratorio bajo condiciones controladas. A pesar de las indudables ventajas que ofrece este método, es necesario solventar una serie de problemas que pueden aparecer y que limitarían el rendimiento del proceso. Además, la explotación comercial de estas técnicas requiere la optimización de una serie de parámetros que, en la mayor parte de los casos, debe hacerse cultivar por cultivar. Entre los factores que se deben tener en cuenta destacan la elección del método de multiplicación, el ajuste de los medios de cultivo (macro- y micronutrientes), reguladores del crecimiento o fitohormonas, la aparición de hiperhidricidad, etc. La empresa Barberet & Blanc, S.A. by Dümmen Orange está situada en Puerto Lumbreras (Murcia) y se dedica, entre otras actividades, a la mejora genética y obtención de nuevas variedades de Limonium sinuatum. Como se ha comentado anteriormente, es necesario depurar la técnica de cultivo in vitro en todas las fases que comprende el proceso con el fin de conseguir plantas de calidad, y por tanto una mejor rentabilidad. Por otra parte, desde un punto de vista estratégico, la realización de este trabajo es muy importante para dicha empresa, ya que añade a su labor de investigación y mejora, la colaboración con de la Universidad Politécnica de Cartagena (UPCT), canalizada a través del Instituto de Biotecnología Vegetal (IBV) de esta institución En este trabajo se describen los resultados de una serie de ensayos planteados para conseguir una mejora del cultivo in vitro de cuatro variedades comerciales de L. sinuatum de distintos colores. SN8946 (violeta), SN9013 (blanca), SN9000 (amarilla) y SN9001 (rosa). Se realizó una selección de material vegetal para estudiar las cuatro etapas clásicas del proceso de micropropagación: establecimiento, multiplicación, enraizamiento y aclimatación, intentado optimizar las condiciones de ciertos parámetros que afectaban a cada una de ellas. Así, se estableció un protocolo de establecimiento alternativo para la variedad de color amarillo a partir de explantes conseguidos de hojas jóvenes; también se vio que en la fase de multiplicación la reducción de la distancia entre de las baldas de las estanterías dentro de la cámara de cultivo in vitro producía un ligero cambio en la intensidad luminosa que no provocaba cambios en ninguno de los parámetros productivos. Además, en esta misma etapa, se pudo observar que con la reducción de la temperatura durante la multiplicación, se conseguía alargar los periodos de subcultivo sin que esto tampoco afectara a los parámetros contemplados en la micropropagación. En la fase de enraizamiento el cambio del regulador de crecimiento utilizado no tuvo consecuencias en el proceso productivo, aunque sí mejoró los porcentajes de plantas con raíces y de supervivencia en aclimatación. En todos los ensayos realizados se evaluó la calidad del material vegetal obtenido tanto a nivel bioquímico, donde se analizaron las concentraciones de diferentes compuestos (pigmentos fotosintéticos, flavonoides, fenoles, etc.), como a nivel agronómico, comparando los valores de producción, longitud, número de espigas y cantidad de ramificaciones de los ensayos, con los que se obtenían de las producciones comerciales de la empresa. Por último, los resultados y conclusiones se completaron con un pequeño estudio económico que se presentó a la empresa, exponiendo los cambios que deberían realizarse en cada una de las fases de la micropropagación de Limonium sinuatum para conseguir una mejor rentabilidad, tanto en el aprovechamiento de instalaciones (cámara de cultivo) como en el ahorro de mano de obra, todo ello con la correspondiente estimación del impacto presupuestario que conlleva la optimización de las etapas del proceso.[ENG] Limonium sinuatum is a species of the Plumbaginaceae family. This species is greatly appreciated because it has a good market both for dry and for fresh flowers. One of the problems presented by this species is the massive production of plants. The conventional propagation of many cultures of Limonium is done by seed or by cuttings, so that the productions of the plant takes between 6 and 8 months, with a limited yield (20-30 %) and in many cases the plants obtained are not homogeneous. Alternatively, in vitro propagation or micropropagation is used, which is carried out in the laboratory under controlled conditions. Despite the undoubted advantages of this method, it is necessary to solve a series of problems that may appear and that would limit the performance of the process. In addition, the commercial exploitation of these techniques requires the optimization of a series of parameters that, in most cases, must be cultivated for cultivation. Among the factors that must be taken into account are the choice of the multiplication methods, the adjustment of the culture media (macro- and micronutrients), growth regulators or phytohormones, the appearance of hyperhydricity, etc. The company Barberet & Blanc, S.A. By Dümmen Orange is located in Puerto Lumbreras (Murcia) and is dedicated, among other activities, to breeding new varieties of Limonium sinuatum. Because of this, it is necessary to purify the technique of in vitro culture in all the phases that the process comprises in order to obtain quality plants, and therefore profitability. For this reason, from a strategic point of view, the accomplishment of this work is very important for this company, since it adds to its work of research and improvement that realizes the collaboration with the Polytechnic University of Cartagena, channeled through the Institute of Plant Biotechnology of this institution. This work consists of a series of trials aimed at improving the in vitro culture of four commercial varieties of L. sinuatum of different colours, SN8946 (violet), SN9013 (white), SN9000 (yellow) and SN9001 (pink). A selection of plant material was made to study the four phases of the micropropagation process: establishment, multiplication, rooting and acclimatization, trying to optimize the conditions of some of the parameters that affected each one. Thus, an alternative establishment protocol was established for the yellow variety from explants obtained from young leaves; It was also observed that in the multiplication phase the reduction of the distance between the shelves within the in vitro culture chamber produced a small change in light intensity that did not cause changes in any of the productive parameters. In addition, this phase could be observed that if the temperature during the multiplication is reduced, it was possible to lengthen the subculture periods without this also affecting the parameters contemplated in the micropropagation. In the rooting phase the growth regulator used was changed without this having consequences in the productive process, improving the percentages of plants with roots and survival in acclimatization. Finally, the quality of the plant material obtained at the biochemical level, where the concentrations of different compounds (photosynthetic pigments, flavonoids, phenols, etc.) and agronomic values were analysed, comparing the values of production, length, number of spikes and number of branches with which they were obtained from commercial productions of the company. Finally, the results and conclusions were completed with a small economic study that was presented to the company, explaining the changes that should be made in each of the phases of the micropropagation of Limonium sinuatum to achieve a better profitability, both in the use of facilities (cultivation chamber) as in saving labor, all with the corresponding estimation of the budgetary impact that entails the optimization of the stages of the process.Escuela Internacional de Doctorado de la Universidad Politécnica de CartagenaUniversidad Politécnica de CartagenaInstituto de Biotecnología Vegetal (IBV)Programa de Doctorado en Técnicas Avanzadas en Investigación y Desarrollo Agrario y Alimentario por la Universidad Politécnica de Cartagen

Design and Implementation of MC-CDMA Systems for Future Wireless Networks

The emerging need for high data rate wireless services has raised considerable interest in MC-CDMA systems. In this work, we describe an MC-CDMA system design process for indoor propagation scenarios. The system specifications and simulations are firstly given, and then implementation aspects on a mixed, multi-DSP and FPGA architecture are presented. In order to reduce development cycle, we propose the use of efficient design methodologies to improve development steps such as complexity evaluation, system distribution according to the architecture, and hardware-software code generation. Implementation results of the considered MC-CDMA system are then given.</p