484 research outputs found

    Expresión diferencial del gen CsGH3-1 y su relación con la formación de raíces adventicias en los brotes de castaño.

    Get PDF
    Peer reviewe

    Comparison of metagenomic profile of patients, meeting criteria for non-celiac gluten sensitivity, with and without response to restrictive diets

    Full text link
    Podeu consultar el III Workshop anual INSA-UB complet a: http://hdl.handle.net/2445/118993Sessió 2. Pòster núm. 2

    Uso de 7Be para cuantificar el impacto de un evento de precipitación intensa sobre la redistribución del suelo en un sitio sometido a cero labranza

    Get PDF
    Durante muchos años el sitio de estudio, ubicado en el centro-sur de Chile (38°37´S 73°04´O), fue cultivado bajo cero labranza sin quema de residuos. A comienzos del 2005, después de la cosecha y previo al inicio de las lluvias de otoño se sometieron a quema los residuos del cultivo, dejando el suelo desnudo sin cobertura vegetal hasta el inicio de un período de precipitaciones intensas ocurrido en Mayo de 2005. Para estimar los montos y distribución espacial de la erosión y sedimentación asociados al periodo de precipitación intensa se utilizaron mediciones de 7Be asociadas a un modelo de conversión de los inventarios de 7Be en montos de redistribución de suelo. La erosión neta y fracción de pérdida de sedimentos desde el sitio de estudio (1.2±0.2 kg m-2 y 88% respectivamente) asociadas al periodo de precipitación intensa fueron considerablemente mayores que las estimadas para el mismo sitio durante el período previo de cero labranza sin quema (16 años) utilizando la técnica del 137Cs (0.14±0.2 kg m-2 a-1 y 19%respectivamente)

    Changes in soil erosion associated with the shift from conventional tillage to a no-tillage system, documented using 137Cs measurements

    Get PDF
    Caesium-137 measurements have been used to document changes in the rate and extent of soil erosion associated with the shift from conventional tillage to a no-till system on a farm in south-central Chile. The study site is located in the Coastal Mountains of the 9th Region (38°37′S 73°04′W), and is characterized by Araucano series Ultisols (Typic Hapludult), a temperate climate and a mean annual precipitation of 1100 mm year-1. A field, which was under conventional tillage until May 1986 and which was subsequently managed using a no-till system, was selected for the study. An approach for using 137Cs measurements to quantify the medium-term erosion and deposition rates associated with the periods of contrasting land management documented previously was employed. This approach involves both a standard method and a simplified method, which permits a larger number of sampling points to be used. In this study, emphasis was placed on application of the simplified method, which has the important advantage of requiring only two 137Cs measurements per sampling point. The results obtained for the study field showed that the implementation of no-till practices, including crop residue management, coincided with a reduction in the net erosion rate by about 87% and the proportion of the study area subject to erosion from 100% to 57%, and therefore significantly decreased soil and nutrient loss. Reduced soil and nutrient loss has important on-site benefits, in terms of sustainable management of the soil resource and maintaining crop productivity, as well as reducing off-site problems associated with the degradation of river water quality

    Análisis de la distribución de hidrógeno en contención y pozo seco de C.N. Cofrentes.

    Full text link
    El desarrollo del modelo de la Contención de C.N. Cofrentes mediante GOTHIC se ha llevado a cabo introduciendo todos los datos geométricos y de estructuras de la Contención, pudiendo así modelar todos los recintos interiores y habitaciones que la componen. De esta forma se ha obtenido un modelo 3D detallado y con la precisión suficiente para el estudio global de la gestión del hidrógeno, permitiendo tener en cuenta, a la hora de la distribución del hidrógeno, la asimetría tanto de la contención como de las descargas de masa y en energía que en ella se realizan, permitiendo simular la distribución del vapor y el hidrógeno presentes en el accidente severo para poder determinar las zonas de mayor riesgo de deflagración o detonación durante la evolución del accident

    Involvement of the cohesin cofactor PDS5 (SPO76) during meiosis and DNA repair in Arabidopsis thaliana

    Get PDF
    Maintenance and precise regulation of sister chromatid cohesion is essential for faithful chromosome segregation during mitosis and meiosis. Cohesin cofactors contribute to cohesin dynamics and interact with cohesin complexes during cellcycle. One of these, PDS5, also known as SPO76, is essential during mitosis and meiosis in several organisms and also plays a role in DANN repair. In yeast, the complex Wapl-Pds5 controls cohesion maintenance and colocalizes with cohesin complexes into chromosomes. In Arabidopsis, AtWAPL proteins are essential during meiosis, however, the role of AtPDS5 remains to be ascertained. Here we have isolated mutants for each of the five AtPDS5 genes(A–E) and obtained, after different crosses between them, double,triple,and even quadruple mutants (Atpds5a Atpds5b Atpds5c Atpds5e). Depletion of AtPDS5 proteins has a weak impact on meiosis, but leads to severe effects on development, fertility, somatic homologous recombination (HR) and DANN repair. Furthermore, this cohesin cofactor could be important for the function of the AtSMC5/AtSMC6 complex. Contrarily to ist function in other species, our results suggest that AtPDS5 is dispensable during the meiotic division of Arabidopsis, although it plays an important role in DANN repair by HR

    Appearance and Maturation of T-Cell Subsets During Rat Thymus Ontogeny

    Get PDF
    In previous papers, we have described the ontogenetical development of thymic stromal-cell components (epithelium, macrophages, dendritic cells) of Wistar rats. Here, we correlate those results with the maturation of rat T-cell precursors along the fetal and postnatal life. First T-cell precursors, which colonize the thymus anlage around days 13-14 of gestation, largely express CD45, CD43, CD53, and Thy 1 cell markers, and in a lesser proportion the OX22 antigen. Rat CD3-CD4-CD8- thymocytes present in the earliest stages of gestation could be subdivided in three major cell subpopulations according to the CD44 and CD25 expression: CD44-/+CD25- → CD44+CD25+ → CD44+CD25- On fetal days 17-18, a certain proportion of CD4-CD8-cells weakly,express the TcRβ chain, in correlation with the appearance of the first immature CD4-CD8+ thymocytes. This cell subpopulation, in progress to the CD4+CD8+ stage, upregulates CD8α before the CD8β chain, expresses the CD53 antigen, and exhibits a high proliferative rate. First mature thymocytes arising from the DP (CD4+CD8+) cells appear on fetal days 20-21. Then, the CD4+:CD8+ cell ratio is ≤1 changing to adult values (2-3) just after birth. Also, the percentage of VβTcR repertoire covered in adult thymus is reached during the postnatal period, being lower during the fetal life. Finally, in correlation with the beginning of thymocyte emigration to the periphery a new wave of T-cell maturation apparently occurs in the perinatal rat thymus

    Dynamic behaviour of AA 2024 under blast loading : experiments and simulations

    Get PDF
    The dynamic behaviour of AA2024-T3 is investigated. Dynamic tensile tests using a servo-hydraulic and a light weight shock testing machine (LSM) have been performed. The servo-hydraulic test machine proves to be more reliable and reaches higher strain rates. Neither test revealed any strain rate effect of AA2024-T3. Two types of fracture tests were carried out to determine the dynamic crack propagation behaviour of this alloy, using prestressed plates and pressurized barrels, both with the help of explosives. The prestressed plates proved to be not suitable, whereas the barrel tests were quite reliable, allowing to measure the crack speeds. Computer simulations with a user defined, rate dependent cohesive zone model were in agreement with experiments, capturing the rate toughening effect

    SiO Outflows in the Most Luminous and Massive Protostellar Sources of the Southern Sky

    Full text link
    (Abridged) High-mass star formation is far less understood than low-mass star formation. It entails molecular outflows, which disturb the protostellar clump. Studying these outflows and the shocked gas they cause is key for a better understanding of this process. This study aims to characterise the behaviour of molecular outflows in the most massive protostellar sources in the Southern Galaxy by looking for evolutionary trends and associating shocked gas with outflow activity. We present APEX SEPIA180 observations (beamwidth \sim36") of SiO outflow candidates of a sample of 32 luminous and dense clumps, candidates to harbouring Hot Molecular Cores. We study the SiO(4-3) line emission, an unambiguous tracer of shocked gas and recent outflow activity, the HCO+^+(2-1) and H13^{13}CO+^+(2-1) lines. 78% of our sample present SiO emission. Nine of these also have wings in the HCO+^+ line, indicating outflow activity. The SiO emission of these 9 sources is more intense and wider than the rest, suggesting that the outflows in this group are faster and more energetic. Three positive correlations between the outflow properties were found, which suggest that more energetic outflows bear to mobilise more material. No correlation was found between the evolutionary stage indicator L/ML/M and SiO outflow properties, supporting that outflows happen throughout the whole high-mass star formation process. We conclude that sources with both SiO emission and HCO+^+ wings and sources with only SiO emission are in virtually the same advanced stage of evolution in the high-mass star formation process. The former present more massive and more powerful SiO outflows than the latter. Thus, looking for more outflow signatures such as HCO+^+ wings could help identify more massive and active massive star-forming regions in samples of similarly evolved sources, as well as sources with older outflow activity.Comment: 24 pages, 37 figures, 11 table

    Estudio del glaucoma primario de ángulo abierto en la provincia de La Rioja

    Get PDF
    El glaucoma es un conjunto de alteraciones oculares, cuya principal característica es el aumento de la presión intraocular que sobrepasa los 20 mm Hg, acompañada con Hipertensión ocular, alteración del nervio óptico y defectos del campo visual. Esta patología es la segunda causa de ceguera irreversible en el mundo.El objetivo del presente trabajo es determinar la prevalencia de Glaucoma Primario Angulo Abierto (GPAA) en la provincia de La Rioja y su relación con patologías sistémicas como hipertensión arterial, diabetes y patologías endémicas regionales como las enfermedades tiroideas y Chagas. Se realizo un diseño descriptivo transversal que incluyo 1174 pacientes entre mujeres y hombres, mayores de 40 años de edad, estudiados en toda la provincia durante el año 2008 y 200
    corecore