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Arbuscular mycorrhizal (AM) symbiosis can provide multiple benefits to the host plant, including improved nutrition and protection against biotic stress. Mycorrhiza induced resistance (MIR) against pathogens and insect herbivores has been reported in different plant systems, but nutrient availability may influence the outcome of the interaction. Phosphorus (P) is a key nutrient for plants and insects, but also a regulatory factor for AM establishment and functioning. However, little is known about how AM symbiosis and P interact to regulate plant resistance to pests. Here, using the tomato-Funneliformis mosseae mycorrhizal system, we analyzed the effect of moderate differences in P fertilization on plant and pest performance, and on MIR against biotic stressors including the fungal pathogen Botrytis cinerea and the insect herbivore Spodoperta exigua. P fertilization impacted plant nutritional value, plant defenses, disease development and caterpillar survival, but these effects were modulated by the mycorrhizal status of the plant. Enhanced resistance of F. mosseae-inoculated plants against B. cinerea and S. exigua depended on P availability, as no protection was observed under the most P-limiting conditions. MIR was not directly explained by changes in the plant nutritional status nor to basal differences in defense-related phytohormones. Analysis of early plant defense responses to the damage associated molecules oligogalacturonides showed primed transcriptional activation of plant defenses occurring at intermediate P levels, but not under severe P limitation. The results show that P influences mycorrhizal priming of plant defenses and the resulting induced-resistance is dependent on P availability, and suggest that mycorrhiza fine-tunes the plant growth vs defense prioritization depending on P availability. Our results highlight how MIR is context dependent, thus unravel molecular mechanism based on plant defence in will contribute to improve the efficacy of mycorrhizal inoculants in crop protection.

ResumenSe realiza un estudio sobre la flotación en columnas de iones cobre utilizando como reactivo colector amilxantato de potasio. Se determina experimentalmente el efecto de la modificación de las variables relación colector/metal, velocidad superficial del gas y del líquido sobre la recuperación, a partir del análisis del modelo matemático-estadístico que caracteriza la flotación de cobre, así como de los fenómenos físico-químicos que tienen lugar, donde se comprueba el papel preponderante de la variable relación colector/metal en la recuperación de cobre. Se estudia además, el efecto del pH como elemento determinante de las características químicas del sistema en la recuperación y la cinética del proceso de flotación. Los resultados experimentales muestran que es posible la recuperación del cobre disuelto para el rango de pH de 4,5 a 12 con predominio de la flotación de precipitados. Palabras claveAmilxantato de potasio; Complejos de cobre; Columna de flotación; Flotación de precipitados. Recovery of copper ion by flotation with potassium amylxanthate AbstractIn this paper a study about the column flotation process of copper ion employing potassium amylxanthate as collector reagent is carried out. The effect on the recovery of copper ion by the modification of variables such as collector/metal relation and surface velocity of gas and liquid was determined experimentally by the analysis of the statistic-mathematical model of the copper flotation process, as well as the physico-chemical phenomena that take place, showing the effect of the collector/metal relation in the process. The effect of pH as the main properties of the chemical system in the recovery and the kinetic of the flotation process is made too. The experimental results shows that the recovery of copper in the pH range of 4,5 -12 is possible with prevalence of precipitate flotation.

En los últimos años la producción de cemento ha ido en aumento fundamentalmente en los países en vías de desarrollo, incrementando las emisiones de CO2 a la atmosfera. Por otra parte, la norma Europea EN 197-1 para la producción de cemento permite incorporar materiales alternativos para disminuir este efecto y a la vez hacer un mejor aprovechamiento de los recursos, así como disminuir el consumo energético durante la producción del clínquer. En este trabajo se evalúa el efecto de la adición de caliza, en distintas proporciones, en la resistencia a la compresión de morteros. Los resultados indican que es posible preparar mezclas en cuya composición se alcance hasta un 20 % de caliza sin que por ello se viole la normativa angolana de control de la calidad del cemento producido. Se presentan los modelos matemáticos que describen el comportamiento o efecto que se produce al adicionar caliza y su influencia en la resistencia a la compresión medida en morteros. Se comprobó a nivel industrial en una planta de cementos angolana que para un 12 % de caliza intermolida con clínquer es posible preparar cemento con valores de resistencia a la compresión dentro de los parámetros establecidos

The purpose of this work was to obtain the thermodynamic stability diagram that characterizes the copper/water/amylxanthate flotation system, as part of the theoretical foundation necessary for the analysis of the copperion flotation process with the flotation collector reagent potassium amylxanthate. From the system of fundamental chemical reactions and with the help of the Medusa software, the Eh-pH diagram was obtained, in which the stability zones of the different chemical species are defined and it is established that in the pH range from 4 to 13, the xanthogenic species of copper(I) and (II) coexist, whose ratio decreases with the increase of pH.