Mejoramiento del arroz de secano para América Latina

Improving upland rice for Latin America The ecosystems for upland rice in Latin America and the Caribbean and their limitations for rice cultivation are analyzed. The sites where the CIAT rice program and the collaborative project that the Center carries out with the French Agricultural Research Centre for International Development (CIRAD) evaluate and select genetic materials for upland conditions are also described, as well as the conventional genetic improvement activities carried out by CIAT since 1981 and those carried out by CIRAD since 1996. These activities include population development through population improvement and recurrent selection. The advances made so far are reported. As a result of these research projects, lines have been developed that present high yield potential and new commercial varieties have been released that have been quickly adopted by farmers. This has allowed the opening of new agricultural frontiers in Colombia’s Eastern Plains, and northern coast regions. In Brazil, the production of upland rice has been stimulated and, in Bolivia, alternatives to upland rice cultivation are being offered.Se analizan los ecosistemas para el arroz de secano de América Latina y el Caribe, las limitaciones que presentan para el cultivo del arroz, y los sitios donde se evalúan y seleccionan materiales genéticos de arroz de secano del Programa de Arroz del CIAT y del proyecto de cooperación con el Centro de Cooperación Internacional en Investigación Agrícola para el Desarrollo (CIRAD), de Francia. Se describen también las actividades de mejoramiento genético convencional desarrolladas por el CIAT desde 1981, y las que realizó el CIRAD desde 1996, es decir, desarrollo de poblaciones mediante la implementación del mejoramiento poblacional y su mejora mediante la selección recurrente. También se presentan algunos datos de los avances obtenidos. Como resultado de estos proyectos de investigación se han desarrollado líneas de elevado potencial productivo y se han liberado nuevas variedades comerciales rápidamente adoptadas por los agricultores. Con ellas se han abierto nuevas fronteras agrícolas en los Llanos Orientales y en la costa norte de Colombia, se ha estimulado la producción del arroz de secano en Brasil y se han ofrecido alternativas al cultivo de arroz de secano en Bolivia

Associahedra via spines

An associahedron is a polytope whose vertices correspond to triangulations of a convex polygon and whose edges correspond to flips between them. Using labeled polygons, C. Hohlweg and C. Lange constructed various realizations of the associahedron with relevant properties related to the symmetric group and the classical permutahedron. We introduce the spine of a triangulation as its dual tree together with a labeling and an orientation. This notion extends the classical understanding of the associahedron via binary trees, introduces a new perspective on C. Hohlweg and C. Lange's construction closer to J.-L. Loday's original approach, and sheds light upon the combinatorial and geometric properties of the resulting realizations of the associahedron. It also leads to noteworthy proofs which shorten and simplify previous approaches.Comment: 27 pages, 11 figures. Version 5: minor correction

Doubly resonant ultrachirped pulses

Ultrachirped pulses for which the frequency chirp is of the order of the transition frequency of a two-level atom are examined. When the chirp is large enough, the resonance may be crossed twice, for positive and negative quadrature frequencies. In this scenario the analytic signal and quadrature decompositions of the field into amplitude and phase factors turn out to be quite different. The corresponding interaction pictures are strictly equivalent, but only as long as approximations are not applied. The domain of validity of the formal rotating wave approximation is dramatically enhanced using the analytic signal representation

Lactococcus lactis carrying the pValac DNA expression vector coding for IL-10 reduces inflammation in a murine model of experimental colitis

Background: Inflammatory bowel diseases (IBD) are intestinal disorders characterized by inflammation in the gastrointestinal tract. Interleukin-10 is one of the most important anti-inflammatory cytokines involved in the intestinal immune system and because of its role in downregulating inflammatory cascades, its potential for IBD therapy is under study. We previously presented the development of an invasive strain of Lactococcus lactis (L. lactis) producing Fibronectin Binding Protein A (FnBPA) which was capable of delivering, directly to host cells, a eukaryotic DNA expression vector coding for IL-10 of Mus musculus (pValac:il-10) and diminish inflammation in a trinitrobenzene sulfonic acid (TNBS)-induced mouse model of intestinal inflammation. As a new therapeutic strategy against IBD, the aim of this work was to evaluate the therapeutic effect of two L. lactis strains (the same invasive strain evaluated previously and the wild-type strain) carrying the therapeutic pValac:il-10 plasmid in the prevention of inflammation in a dextran sodium sulphate (DSS)-induced mouse model. Results: Results obtained showed that not only delivery of the pValac:il-10 plasmid by the invasive strain L. lactis MG1363 FnBPA+, but also by the wild-type strain L. lactis MG1363, was effective at diminishing intestinal inflammation (lower inflammation scores and higher IL-10 levels in the intestinal tissues, accompanied by decrease of IL-6) in the DSS-induced IBD mouse model. Conclusions: Administration of both L. lactis strains carrying the pValac:il-10 plasmid was effective at diminishing inflammation in this murine model of experimental colitis, showing their potential for therapeutic intervention of IBD.Fil: Zurita Turk, Meritxell. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; BrasilFil: del Carmen, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Santos, Ana C. G.. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; BrasilFil: Pereira, Vanessa Bastos. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; BrasilFil: Cara, Denise C.. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; BrasilFil: Leclercq, Sophie Y.. Fundaçao Ezequiel Dias. Laboratório de Inovaçao Biotecnológica; BrasilFil: de Moreno, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Azevedo, Vasco. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; BrasilFil: Chatel, Jean-Marc. Universidade Federal do Minas Gerais; BrasilFil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Miyoshi, Anderson. Universidade Federal Do Minas Gerais. Instituto de Cs.biologicas; Brasi

Novel insights into host-fungal pathogen interactions derived from live-cell imaging

Acknowledgments The authors acknowledge funding from the Wellcome Trust (080088, 086827, 075470 and 099215) including a Wellcome Trust Strategic Award for Medical Mycology and Fungal Immunology 097377 and FP7-2007–2013 grant agreement HEALTH-F2-2010-260338–ALLFUN to NARG.Peer reviewedPublisher PD

Phenotypic heterogeneity in attachment of marine bacteria toward antifouling copolymers unraveled by AFM

Up to recent years, bacterial adhesion has mostly been evaluated at the population level. Single cell level has improved in the past few years allowing a better comprehension of the implication of individual behaviors as compared to the one of a whole community. A new approach using atomic force microscopy (AFM) to measure adhesion forces between a live bacterium attached via a silica microbead to the AFM tipless cantilever and the surface has been recently developed. The objectives of this study is to examine the bacterial adhesion to a surface dedicated to ship hulls at the population and the cellular level to understand to what extent these two levels could be correlated. Adhesion of marine bacteria on inert surfaces are poorly studied in particular when substrata are dedicated to ship hulls. Studying these interactions in this context are worthwhile as they may involve different adhesion behaviors, taking place in salty conditions, using different surfaces than the ones usually utilized in the literacy. FRC (fouling release coatings)-SPC (self-polishing coatings) hybrids antifouling coatings have been used as substrata and are of particular interest for designing environmentally friendly surfaces, combining progressive surface erosion and low adhesion properties. In this study, a hybrid coating has been synthetized and used to study the adhesion of three marine bacteria, displaying different surface characteristics, using microplate assays associated with confocal scanning laser microscopy (CSLM) and AFM. This study shows that the bacterial strain that appeared to have the weakest adhesion and biofilm formation abilities when evaluated at the population level using microplates assays and CSLM, displayed stronger adhesion forces on the same surfaces at the single cell level using AFM. In addition, one of the strains tested which presented a strong ability to adhere and to form biofilm at the population level, displayed a heterogeneous phenotypic behavior at the single cell level. Therefore, these results suggest that the evaluation of adhesion at the population level cannot always be correlated with adhesion forces measured individually by AFM and that some bacteria are prone to phenotypic heterogeneity among their population

Formation and interactions of cold and ultracold molecules: new challenges for interdisciplinary physics

Progress on researches in the field of molecules at cold and ultracold temperatures is reported in this review. It covers extensively the experimental methods to produce, detect and characterize cold and ultracold molecules including association of ultracold atoms, deceleration by external fields and kinematic cooling. Confinement of molecules in different kinds of traps is also discussed. The basic theoretical issues related to the knowledge of the molecular structure, the atom-molecule and molecule-molecule mutual interactions, and to their possible manipulation and control with external fields, are reviewed. A short discussion on the broad area of applications completes the review.Comment: to appear in Reports on Progress in Physic

BRSMG Curinga: cultivar de arroz de terras altas de ampla adaptação para o Brasil.

O objetivo deste trabalho é a apresentação das características da BRSMG Curinga, a sétima cultivar de arroz de terras altas originária da colaboração da Embrapa com o programa CIAT/CIRAD, lançada em 2005 para cultivo em condições de terras altas nos Estados de Minas Gerais, Goiás, Mato Grosso, Rondônia, Pará, Roraima, Maranhão, Piauí e Tocantins.bitstream/CNPAF/23577/1/comt_114.pd