Técnicas de rehabilitación de plantaciones improductivas de cacao

El presente artículo aporta elementos para superar las limitaciones que genera esta problemática al sector productivo ofreciendo alternativas tecnológicas para realizar la rehabilitación de plantaciones improductivas de cacao, en las condiciones del pequeño cacaocultor.Cacao-Theobroma caca

Interacciones multitrófica en la rizosfera de aguacate de la cepa de biocontrol pseudomonas chlororaphis PCL1606 con el hongo fitopatógeno rosellinia necatrix CH53

Pseudomonas pseudoalcaligenes AVO110 es un agente de biocontrol frente a la podredumbre radicular blanca causada por Rosellinia necatrix, seleccionado por su eficiente capacidad de colonizar de forma competitiva las puntas radiculares de plantas de aguacate, así como por su actividad antagonista in vitro frente a este patógeno. Su principal mecanismo de biocontrol se basa tanto en la competición por nicho y nutrientes, como en la colonización competitiva de las hifas de R. necatrix, alimentándose de metabolitos fúngicos. Para detectar genes de AVO110 implicados en su multiplicación y supervivencia en presencia de exudados fúngicos, se analizó una colección de mutantes, de entre los cuales, 26 mostraron un crecimiento atenuado (Growth Attenuated Mutants, mutantes GAM). Los mutantes GAM-22, GAM-24 y GAM-26, afectados en genes codificadores de una exodeoxirribonuclesa, una histidina kinasa y un regulador transcripcional, respectivamente, mostraron un defecto en la capacidad de colonización de las raíces de plantas de aguacate con respecto a la cepa silvestre. Sin embargo, el mutante GAM-3, afectado en una proteína con dominios GGDEF/EAL/PAS, mostró una mayor capacidad de colonización de la rizosfera. Finalmente, los mutantes GAM-3 y GAM-26 también mostraron un incremento en la formación de biopelícula in vitro en comparación con la cepa silvestre. *Este trabajo ha sido financiado por el MINECO (AGL-2011-30354-C02-01) y por la Junta de Andalucía (P10-AGR.5797), cofinanciados por el Fondo Social Europeo.*Este trabajo ha sido financiado por el MINECO (AGL-2011-30354-C02-01) y por la Junta de Andalucía (P10-AGR.5797), cofinanciados por el Fondo Social Europeo. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Estudio de la cavitación en las bombas centrifugas

Esta monografía fue hecha con el propósito de comprender el fenómeno de la cavitacion , que es un problema importante para el análisis en el diseño de la mecanica de fluidos y la hidráulica. Se pretende demostrar que los efectos de la cavitacion se transmiten a las estructuras próximas reduciendo el rendimiento, pudiendo causar serios daños materiales a las instalaciones, que por otra parte son causantes de la corrosión generadora de partículas de metal. El tema es importante ya que conociendo en si el problema se puede considerar soluciones que no perturben la continuidad del flujo como lo es disminuir el caudal, la altura manométrica y el rendimiento de la bomba. El trabajo consiste en el estudio de estos fenómenos, como principales en el diseño de los sistemas hidráulicos; Sus investigaciones buscan disminuir o acabar con este problemaIncluye bibliografí

Dependencia con la presión del índice de refracción del AgGaS2

En el presente trabajo estudiamos el comportamiento en presión del espectro de absorción (óptica de una muestra monocristalina de AgGaS2, realizando medidas en el rango de energías del infrarrojo, desde 0.30 hasta 0.70 eV, para presiones P inferiores a 4 GPa y temperatura ambiente T, utilizando para ello una celda de yunques de diamantes en combinación con la técnica de micro?espectroscopia infrarroja [1]. Con este estudio determinamos la variación de su índice de refracción n en función de la presión, en el rango de estabilidad de la estructura calcopirita [2?6], así como la variación en presión de las constantes dielectricas estática (?0) y de alta frecuencia (??). Nuestros resultados del índice de refracción a presión y temperatura ambiente en el AgGaS2 pueden compararse con los valores experimentales reportados por Boyd et al.In this work, we study the pressure behavior of the optical absorption spectrum of a single crystal AgGaS2, taking measurements in the infrared energy range from 0.30 up to 0.70 eV for pressures values P below 4GPa and room temperature T, using a diamond anvil cell in combination with infrared micro spectroscopy technique [1]. With this study, we determine the refraction index n variations in terms of pressure within the stability range of the chalcopyrite structure [2?6] as well as the changes under pressure of both the static (?0) and high frequency (??) dielectric constants. These results can be compared with the experimental values reported by Boyd et al

Propuesta utilizando un componente de software para la integración de las plataformas Moodle-Dspace con el protocolo swordv1

En esta investigación se ha explicado la importancia de la interoperabilidad entre Moodle-DSpace en el contexto de cuantificar y visibilizar los recursos digitales que son generados por los docentes en los cursos virtuales, debido a que dichos contenidos están restringidos para los estudiantes que no estén matriculados en el curso. Se hace especial énfasis en el método model-driven que permite a los desarrolladores construir sus propias variantes a los módulos basándose en sus necesidades. Asimismo, se demuestra la relevancia del estudio está claramente apoyada porlos resultados actuales, para obtener un componente informático estable para la sumisión de los contenidos digitales a los repositorios institucionales. En síntesis, se logró la interoperabilidad entre las plataformas a través del protocolo SWORD v1 y el paquete METS. Sin embargo,se requiere más trabajo adicional en los módulos con el fin de implementar otros aspectos en el registro de los metadatos en el repositorio

LIPSS manufacturing with regularity control through laser wavefront curvature

Laser-Induced Periodic Surface Structures (LIPSS) manufacturing is a convenient laser direct-writing technique for the fabrication of nanostructures with adaptable characteristics on the surface of virtually any material. In this paper, we study the influence of 1D laser wavefront curvature on nanoripples spatial regularity, by irradiating stainless steel with a line-focused ultrafast laser beam emitting 120 fs pulses at a wavelength of 800 nm and with 1 kHz repetition rate. We find high correlation between the spatial regularity of the fabricated nanostructures and the wavefront characteristics of the laser beam, with higher regularity being found with quasi-plane-wave illumination. Our results provide insight regarding the control of LIPSS regularity, which is essential for industrial applications involving the LIPSS generation technique

Phase separation in double exchange systems

Ferromagnetic systems described by the double exchange model are investigated. At temperatures close to the Curie temperature, and for a wide range of doping levels, the system is unstable toward phase separation. The chemical potential decreases upon increasing doping, due to the significant dependence of the bandwidth on the number of carriers. The reduction of the electronic bandwidth by spin disorder leads to an enormously enhanced thermopower which peaks near T_c, with a sign opposite that predicted by a rigid band model.Comment: 4 pages, 2 encapsulated PostScript figure

Tailoring diamond's optical properties via direct femtosecond laser nanostructuring

We demonstrate a rapid, accurate, and convenient method for tailoring the optical properties of diamond surfaces by employing laser induced periodic surface structuring (LIPSSs). The characteristics of the fabricated photonic surfaces were adjusted by tuning the laser wavelength, number of impinging pulses, angle of incidence and polarization state. Using Finite Difference Time Domain (FDTD) modeling, the optical transmissivity and bandwidth was calculated for each fabricated LIPSSs morphology. The highest transmission of ~99.5% was obtained in the near-IR for LIPSSs structures with aspect ratios of the order of ~0.65. The present technique enabled us to identify the main laser parameters involved in the machining process, and to control it with a high degree of accuracy in terms of structure periodicity, morphology and aspect ratio. We also demonstrate and study the conditions for fabricating spatially coherent nanostructures over large areas maintaining a high degree of nanostructure repeatability and optical performance. While our experimental demonstrations have been mainly focused on diamond anti-reflection coatings and gratings, the technique can be easily extended to other materials and applications, such as integrated photonic devices, high power diamond optics, or the construction of photonic surfaces with tailored characteristics in general

Suppressive ability against Rosellinia Necatrix of agricultural soils

Comunicación a congreso internacionalThe use of organic soil amendments to enhance the suppressiveness of natural soils has been proposed as an additional strategy to control plant diseases. Avocado is one of the main subtropical crops in southern Spain and white root rot, caused by the fungus Rosellinia necatrix, one of the most serious problems. Previous studies on this pathosystem have shown that application of composted almond shells caused a change in soil microbial communities of both population and functional level. In this work, evaluation of the suppressive capacity of almond shells amended soils have performed. “In vitro” assays using two different susceptible plants, Persea americana (avocado) and Triticum aestivum (wheat), indicate a clear relationship between soil microbial communities and suppressiveness. Addition of composted almond shells to the agricultural soil resulted in increased suppressiveness against R. necatrix, directly associated to microbial components, since suppressiveness was reduced when the soil was pasteurized, and partially recovered when the pasteurized soil was complemented with field soil. Different strains producing antifungal compounds were correlated with suppressiveness by molecular approaches.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech. Plan Nacional I+D+I from Ministerio de Economía (MINECO,Spain) (AGL2011-30354-C02-01) and co-financed by FEDER funds (EU). C. Vida was supported by a PhD fellowship from the FPI program of MINECO

GM and KM immunoglobulin allotypes in the Galician population: new insights into the peopling of the Iberian Peninsula

<p>Abstract</p> <p>Background</p> <p>The current genetic structure of Iberian populations has presumably been affected by the complex orography of its territory, the different people and civilizations that settled there, its ancient and complex history, the diverse and persistent sociocultural patterns in its different regions, and also by the effects of the Iberian Peninsula representing a refugium area after the last glacial maximum. This paper presents the first data on <it>GM </it>and <it>KM </it>immunoglobulin allotypes in the Galician population and, thus, provides further insights into the extent of genetic diversity in populations settled in the geographic extremes of the Cantabrian region of northern Spain. Furthermore, the genetic relationships of Galicians with other European populations have been investigated.</p> <p>Results</p> <p>Galician population shows a genetic profile for <it>GM </it>haplotypes that is defined by the high presence of the European Mediterranean <it>GM</it>*<it>3 23 5* </it>haplotype, and the relatively high incidence of the African marker <it>GM*1,17 23' 5*</it>. Data based on comparisons between Galician and other Spanish populations (mainly from the north of the peninsula) reveal a poor correlation between geographic and genetic distances (<it>r </it>= 0.30, <it>P </it>= 0.105), a noticeable but variable genetic distances between Galician and Basque subpopulations, and a rather close genetic affinity between Galicia and Valencia, populations which are geographically separated by a long distance and have quite dissimilar cultures and histories. Interestingly, Galicia occupies a central position in the European genetic map, despite being geographically placed at one extreme of the European continent, while displaying a close genetic proximity to Portugal, a finding that is consistent with their shared histories over centuries.</p> <p>Conclusion</p> <p>These findings suggest that the population of Galicia is the result of a relatively balanced mixture of European populations or of the ancestral populations that gave rise to them. This would support the importance of the migratory movements that have taken place in Europe over the course of recent human history and their effects on the European genetic landscape.</p