el estudio de comportamiento a nivel seccional. Entre los diversos procedimientos que se disponen a tal efecto, encontramos el "Método Multicapa". El método introducido en un artículo previo, será de nuevo tratado en este segundo texto para estudiar el concepto de ductilidad a nivel de sección, en elementos de hormigón armado, y con la idea fundamental de mostrar las ventajas del método en relación al comportamiento No lineal de los materiales.Durante el proyecto sísmico de una estructura los métodos Diagramas momento-curvatura para secciones de hormigón armado. Determinacion del valor de ductilidad local de una sección de hormigón armado. Empleo del programa matlab en aplicaciones estructurales a nivel seccional (parte II). Moment-curvature diagrams for reinforced concrete sections. Sectional ductility ratio calculation. Applications related to section study using matlab (part II). EResumen-En el entorno de la ingeniería de estructuras, resulta de interés el estudio de comportamiento a nivel seccional. Entre los diversos procedimientos que se disponen a tal efecto, encontramos el "Método Multicapa". El método introducido en un artículo previo, será de nuevo tratado en este segundo texto para estudiar el concepto de ductilidad a nivel de sección, en elementos de hormigón armado, y con la idea fundamental de mostrar las ventajas del método en relación al comportamiento No lineal de los materiales.Palabras clave-Ductilidad, curvatura; momento-curvatura; hormigón; matlab; acero; método multicapa; rotula plástica.Abstract-Sectional study it is an important matter from structural engineering point of view. Among the different available procedures in the present technical paper Multi-layer Method will be treated. The Method which was presented in the previous article, once again will be used in this document to deal in this time with ductility concept in reinforced concrete sections. Also the advantages of the method shall be exposed regarding to Nonlinear material behavior.Index Terms-Ductility; curvature; momento-curvature; concrete; matlab; steel; multilayer method; plastic hinge. de análisis (como por ejemplo el método del empuje incremental o "pushover" en sus diferentes posibilidades) requieren la definición de diagramas momento-curvatura de las secciones de los elementos que la componen. Entre la información que aportan estos diagramas, encontramos el concepto de ductilidad a nivel seccional. La ductilidad se define como el cociente entre la curvatura última y la curvatura elástica o asociada al comienzo de la plastificación de la armadura de refuerzo. En el presente artículo se pretende determinar los valores de curvatura asociados al momento flector resultado de la primera plastificación de la armadura y al momento último de la sección, y por lo tanto el valor de la ductilidad a nivel seccional. La obtención de estos parámetros se llevará a cabo mediante un código programado en Matlab.También es objeto de este artículo describir someramente las relaciones entre la ductilidad a nivel de sección o local con la...

Rust fungi are some of the most devastating pathogens of crop plants. They are obligate biotrophs, which extract nutrients only from living plant tissues and cannot grow apart from their hosts. Their lifestyle has slowed the dissection of molecular mechanisms underlying host invasion and avoidance or suppression of plant innate immunity. We sequenced the 101-Mb genome of Melampsora laricipopulina, the causal agent of poplar leaf rust, and the 89-Mb genome of Puccinia graminis f. sp. tritici, the causal agent of wheat and barley stem rust. We then compared the 16,399 predicted proteins of M. larici-populina with the 17,773 predicted proteins of P. graminis f. sp tritici. Genomic features related to their obligate biotrophic lifestyle include expanded lineage-specific gene families, a large repertoire of effector-like small secreted proteins, impaired nitrogen and sulfur assimilation pathways, and expanded families of amino acid and oligopeptide membrane transporters. The dramatic up-regulation of transcripts coding for small secreted proteins, secreted hydrolytic enzymes, and transporters in planta suggests that they play a role in host infection and nutrient acquisition. Some of these genomic hallmarks are mirrored in the genomes of other microbial eukaryotes that have independently evolved to infect plants, indicating convergent adaptation to a biotrophic existence inside plant cells.comparative genomics | plant pathogen | basidiomycete | evolution | rust disease

The growing human population and a changing environment have raised significant concern for global food security, with the current improvement rate of several important crops inadequate to meet future demand . This slow improvement rate is attributed partly to the long generation times of crop plants. Here, we present a method called 'speed breeding', which greatly shortens generation time and accelerates breeding and research programmes. Speed breeding can be used to achieve up to 6 generations per year for spring wheat (Triticum aestivum), durum wheat (T. durum), barley (Hordeum vulgare), chickpea (Cicer arietinum) and pea (Pisum sativum), and 4 generations for canola (Brassica napus), instead of 2-3 under normal glasshouse conditions. We demonstrate that speed breeding in fully enclosed, controlled-environment growth chambers can accelerate plant development for research purposes, including phenotyping of adult plant traits, mutant studies and transformation. The use of supplemental lighting in a glasshouse environment allows rapid generation cycling through single seed descent (SSD) and potential for adaptation to larger-scale crop improvement programs. Cost saving through light-emitting diode (LED) supplemental lighting is also outlined. We envisage great potential for integrating speed breeding with other modern crop breeding technologies, including high-throughput genotyping, genome editing and genomic selection, accelerating the rate of crop improvement.

Leaf rust caused by Puccinia triticina is the most common and widely distributed of the three wheat rusts. Losses from leaf rust are usually less damaging than those from stem rust and stripe rust, but leaf rust causes greater annual losses due to its more frequent and widespread occurrence. Yield losses from leaf rust are mostly due to reductions in kernel weight. Many laboratories worldwide conduct leaf rust surveys and virulence analyses. Most currently important races (pathotypes) have either evolved through mutations in existing populations or migrated from other, often unknown, areas. Several leaf rust resistance genes are cataloged, and high levels of slow rusting adult plant resistance are available in high yielding CIMMYT wheats. This paper summarizes the importance of leaf rust in the main wheat production areas as reflected by yield losses, the complexity of virulence variation in pathogen populations, the role cultivars with racespecific resistance play in pathogen evolution, and the control measures currently practiced in various regions of the world.

Race-specific resistance genes protect the global wheat crop from stem rust disease caused by f. sp. () but are often overcome owing to evolution of new virulent races of the pathogen. To understand virulence evolution in , we identified the protein ligand (AvrSr50) recognized by the Sr50 resistance protein. A spontaneous mutant of virulent to contained a 2.5 mega-base pair loss-of-heterozygosity event. A haustorial secreted protein from this region triggers-dependent defense responses in planta and interacts directly with the Sr50 protein. Virulence alleles of have arisen through DNA insertion and sequence divergence, and our data provide molecular evidence that in addition to sexual recombination, somatic exchange can play a role in the emergence of new virulence traits in.