Influencia de la fertilización fosfatada en la clorosis férica

La clorosis férrica, caracterizada por un amarilleamiento internervial de las hojas más jóvenes de la planta, se debe a una nutrición inadecuada en hierro (Fe). Esta deficiencia aparece en muchas plantas que crecen sobre suelos calcáreos, afectando a cultivos de gran importancia económica en el área mediterránea tales como el olivo y la vid. El contenido en carbonatos y el contenido y cristalinidad de los óxidos de Fe son factores edáficos clave en el problema. El efecto de la fertilización fosfatada es en cambio poco conocido y ha sido motivo de debate, por lo que el objetivo principal de la presente tesis doctoral fue aclarar la influencia del fósforo (P) en la disponibilidad de Fe en plantas sensibles a ese problema. En el segundo capítulo de esta tesis se muestra el comportamiento de plantas de estrategia I (garbanzo, altramuz y cacahuete) y estrategia II (sorgo) que fueron cultivadas en maceta sobre sustratos modelos inductores de clorosis férrica consistentes en mezclas de arena silícea recubierta de ferrihidrita (FOCS) como fuente de Fe para la planta, arena calcárea (CCS) para simular las condiciones de los suelos calcáreos y arena silícea como medio inerte. Se realizaron un total de 5 ensayos de duración inferior a un mes con dosis de P entre 2.5 y 25000 μg P por maceta de 250 g. La concentración de clorofila en hoja se incrementó al aumentar la proporción de FOCS (Fe biodisponible) del sustrato para todos los cultivos, mientras que la proporción de CCS tuvo un efecto negativo en las plantas de estrategia I, no afectando en cambio al sorgo. La fertilización fosfatada redujo la disponibilidad del Fe en las plantas que crecieron en sustrato artificial con bajo contenido en FOCS, independientemente de la estrategia de adquisición de este elemento. El capítulo tercero trata del efecto de las propiedades del suelo en el posible agravamiento de la clorosis férrica inducido por el P. En un primer experimento desarrollado en cámara de crecimiento con altramuz (estrategia I) y sorgo (estrategia II) cultivados en 24 suelos calcáreos se observó que la concentración de clorofila en hoja era menor para las plantas cuyo suelo había sido fertilizado con una dosis alta de P (25000 μg P por maceta de 250 g) respecto a las plantas control (2.5 μg P por maceta). La disminución de clorofila en hoja fue más evidente en altramuz que en sorgo, debido a que su estrategia de adquisición de Fe es menos eficiente. El efecto era mayor cuando la cobertura de los óxidos de Fe poco cristalinos por el P, medida por la relación entre el P Olsen y el Fe extraíble por oxalato amónico ácido (Feox), era alta. Para el sorgo, la fertilización fosfatada incrementó el contenido en clorofila en plantas desarrolladas en suelos con baja relación P Olsen/ Feox, no habiendo efecto o disminuyendo el contenido en clorofila en el resto de los casos y...Iron chlorosis, which reflects in internerval yellowing in young plant leaves, results from an inadequate supply of iron (Fe). This deficiency is common among plants growing on calcareous soils and affects crops with a high economic significance in the Mediterranean region such as olives and vines. Carbonate contents, and Fe oxide contents and crystallinity, are key factors for this problem; by contrast, the potential impact of phosphate fertilizers is poorly known and controversial. The primary aim of this doctoral work was to clarify the influence of phosphorus (P) on Fe availability in chlorosis-prone plants. Chapter 2 of this doctoral dissertation examines the behaviour of Strategy I (chickpea, lupin and peanut) and Strategy II plants (sorghum) grown in pots containing chlorosis-inducing model substrates consisting of siliceous sand covered with ferrihydrite (FOCS) as a source of plant Fe, calcareous sand (CCS) to simulate the typical conditions in calcareous soils and siliceous sand as inert medium. A total of five experiments involving the use of P at rates of 2.5–25 000 μg per 250 g pot for less than one month were performed. Leaf chlorophyll contents increased with increasing proportion of FOCS (bioavailable Fe) in the substrate in all crops; on the other hand, increasing the proportion of CCS had an adverse effect on Strategy I plants but no effect on sorghum. Phosphate fertilization reduced Fe availability in the plants grown in substrates with a low content in FOCS irrespective of the plant uptake strategy for this element. Chapter 3 deals with the potential influence of soil properties on P-induced Fe chlorosis, which was examined by growing lupin (Strategy I) and sorghum (Strategy II) on 24 different calcareous soils in a growth chamber. Leaf chlorophyll contents were found to be low in the plants grown on substrates receiving P at a high rate (25 000 μg P per 250 g pot) relative to control treatment (2.5 μg P per pot). The reduction in chlorophyll was more marked in lupin than in sorghum by effect of the former having a less efficient Fe uptake strategy. The effect was especially strong when the coverage of poorly crystalline Fe oxides by P as measured by the ratio of Olsen P to acid ammonium oxalateextractable Fe (Feox) was high. Phosphorus fertilization increased chlorophyll contents in the sorghum plants grown on soils with a low Olsen P / Feox ratio, but no effect or reduced the leaf chlorophyll content in any others; also, it increased overall plant weight. A second experiment was conducted in a shade house from 2009 to 2011 by using ‘Arbequina’ olives grown on calcareous soils with a similar Olsen P / Feox ratio but supplied with P at 5 different rates (0–1.3 g P per 6.5 kg..

Generational Portrait of Spanish Society in the Face of Climate Change. A Question to Consider for the Green Economy under the Well-Being Approach

Climate change is emerging as an issue of progressive attention, and therefore awareness, in societies. In this work, the problem is addressed from a generational perspective in Spanish society and is carried out from the approaches of awareness, human action, and self-responsibility. All this from the search of the subjective well-being and the citizens' happiness, as one of the bases of sustainable development initiatives. With data from the European Social Survey R8, from EUROSTAT, we work in two phases: (1) descriptive and inferential on possible associations of the items with the variable Age, and (2) calculation of probabilities between groups through logistic regression. The results confirm a general awareness, but with apparent statistical differences between age groups. In general, the youngest are the most aware, blame human activity most intensely, are the most concerned, and are the most willing to act. And it is the older people who are less aware of all these issues. Based on this finding, and from the approach mentioned above, it is recommended that leaders, both in the macroeconomic and microeconomic sectors, develop initiatives that sensitize and encourage older age groups

Different Solvents for Organosolv Pulping

Organosolv pulping is a two-stage process involving hydrolysis (decomposition of wood by use of a catalyst) and removal of lignin with an organic solvent (usually a mixture of alcohol and water). The main disadvantage of using an alcohol is its low boiling point, which requires operating at a high pressure and hence using special equipment that is expensive to purchase and operate. One solution to this problem is using alternative organic solvents that afford operation at pressure levels similar to those of classic pulping processes (e.g., the Kraft process). This chapter provides a comprehensive literature review on the organosolv-based production of cellulose pulp by using alternative solvents such as glycols, phenols, esters, organic acids, acetone and amines

Variation in dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae) assemblages in a tropical forest remnant from a Mexican National Park

The Cañón del Sumidero National Park (PNCS) is a priority area for conservation, but there are few studies on its fauna, which evidences the need for further basic studies to produce adequate knowledge on its biodiversity. This study aimed to determine dung beetle assemblages temporal distribution, trophic preference, and daily activity patterns. We conducted samplings using baited pitfall traps in a PNCS tropical sub deciduous forest remnant, during the dry and rainy seasons between 2014 and 2015. We captured a total of 863 individuals of 20 species, 12 genera, and five tribes of Scarabaeinae. Estimators suggest that we obtained high faunistic representation (> 80%), but species richness is low compared to other regional studies. The community was characterized by a high number of rare species and few dominant species. We captured the greatest richness and abundance during rainy months, however, species composition between seasons did not differ significantly. Trophic preference was mainly generalist and we considered only four species as specialists to tapir dung. We observed a clear segregation between activity hours. Nevertheless, we determined only nine species as specialists (six nocturnal and three diurnal) and two others had generalist habits. The low diversity we found could be influenced by the constant pressure of the urban area and non-native species within the park, which alter the dung beetle assemblages. However, performing samplings for longer periods and using a wider range of resources would help us obtain more robust results and better understand species distribution patterns

Innovative Desalination System Driven by a Solar Micro Gas Turbine for Off-Grid Applications

Past work by the authors has suggested that Solar micro Gas Turbines (SmGTs) can be used cost-effectively to produce electric power and heat for freshwater production through desalination, mainly in off-grid locations. This is further studied in this work, presenting a detailed description of system performance at design and part-load conditions, as well as the characteristics of the components of the SmGT and the desalination unit. To this end, the SmGT is assessed first, considering techniques that achieve a greater off-design performance such as incorporating Variable Inlet Guide Vanes (VIGVs) at the compressor inlet, and including the sensitivity to control strategies and ambient conditions, exploring their expectedly very negative impact on the SmGT performance. Water treatment system is comprised of two elements. A Reverse Osmosis desalination unit is driven by the electric power produced by the SmGT. This produces brine with high salt concentration to be partially treated further in a Zero Liquid Discharge (ZLD) unit driven by the exhaust gases of the microturbine (at about 250-300ºC), where the sensible heat of this stream is harvested by the ZLD unit to “dry” and concentrate the effluent. Finally, the potential and the operational limitations of the ZLD system are discussed, supplemented by an experimental proof of concept where its feasibility was verified

Production of Cellulosic Pulp from Reed (Phragmites australis) to Produce Paper and Paperboard

Due to the global increase in the demand for paper and cardboard, and depletion in some areas of wood resources (main raw material in the paper industry), it has been necessary to investigate new raw materials to substitute the conventional ones. In this work, Phragmites australis, commonly known as reed, has been studied. It has been characterized the chemical composition of the raw material by determining the ash content, α-cellulose, holocellulose, lignin and their extractables in ethanol, 1% soda and hot water. Subsequently three pulping processes have been conducted, using the “soda method" under three different operating conditions. The cellulosic pulps and the papersheets made from the pulps were analysed in order to determine the chemical and physical properties following the relevant TAPPI, UNE and ISO standards. Comparing the results obtained, it can be possible to conclude that the pulp obtained under the following operating conditions: 175°, 90 minutes and 14% of NaOH, presents the best results

Estimación de la producción íctica del río Hozgarganta

Se ha estudiado la producción de las especies de peces en un tramo de 100 m de longitud en el río Hozgarganta durante la primavera de 2003. Los resultados destacan como especie dominante al barbo (B. sclateri) y en menor número a la boga (C. willkommii). Con una estructura poblacional consolidada, aparece una pequeña y joven población de cachuelos (L. pyrenaicus) y pocos individuos jóvenes de anguila (Anguilla anguilla) que remontan el río aguas arriba desde la desembocadura del Guadiar

Towards a new definition of the Middle Neolithic in the southern Iberian peninsula: Grañena Baja, Jaén

En este trabajo presentamos los resultados de las excavaciones en el yacimiento arqueológico de Grañena Baja (Jaén), correspondientes a la primera fase detectada en el mismo. Destaca la posible existencia de un gran foso segmentado, asociado a una cultura material hasta ahora no caracterizada de forma específica en el sur de la península ibérica. Cerámicas de perfil compuesto y borde reforzado con decoraciones sencillas componen el registro. Láminas de formato medio y grande, talón liso y extraídas por percusión indirecta caracterizan los instrumentos líticos. Las dataciones disponibles sitúan en el tercer cuarto del V milenio cal AC el momento de plena ocupación en dicha fase. Esas características dotan al yacimiento de un valor excepcional para completar el vacío existente entre el Neolítico Antiguo y el Neolítico Reciente en gran parte del mediodía peninsular, donde los contextos asociados a dichas cronologías son escasos. Grañena Baja constituye pues una oportunidad única para la caracterización de un Neolítico Medio hasta ahora escurridizo.This work presents the results of the first phase detected at the archaeological site of Grañena Baja (Jaén). The possible existence of a large segmented ditch is one of the most outstanding features, associated with a material culture that has not been specifically characterized in the southern Iberia. The ceramic types stand out for their composite profile and reinforced rims, as well as having decorations simply executed. Blades of medium and large format with straight bases and obtained by means of indirect percussion characterize the lithic industry. Radiocarbon dates place the site’s occupation in the third quarter of the 5th Millennium cal BC. This information makes an important contribution to filling the gap between the Early and the Recent Neolithic in southern Iberia, a region where good evidence for the Middle Neolithic is scarce.La empresa Laura Mercado Gestión del Patrimonio y Servicios Arqueológicos, SLU, realizó la excavación dirigida por Elisabet Conlin con el apoyo técnico de Laura Mercado, Inés Casas, Rosa Gil, Miguel López, Manuel Silva (†), Juan M. Guijo y Elena Vera. Parte del estudio subsecuente y la redacción de este trabajo se financiaron gracias a un contrato Juan de la Cierva (RMMS) del Programa Estatal de Promoción del Talento y su Empleabilidad, Plan Estatal de Investigación Científica y Técnica de Innovación 2013-2016 (MINECO)

Pronóstico de la cantidad de estudiantes que se matriculan en los espacios académicos con mayor demanda en el programa de ingeniería industrial de la fundación universitaria los libertadores

Las series de tiempo adquieren una atención especial en los diversos programas académicos ya que a través de estas se puede llegar a comprender la dinámica de potenciales inscritos en dichos espacios. En este artículo se propone el uso del método de suavizamiento exponencial Holt-Winters para llegar a estimar la cantidad de estudiantes matriculados en los espacios académicos que ofrece el programa de Ingeniería Industrial de la Fundación Universitaria Los Libertadores de manera que dicha Institución pueda tener una mejor proyección de los recursos humanos, físicos y tecnológicos que pondrá a disposición de sus estudiantes. A partir de los análisis y proyecciones realizadas a las diez materias con mayor número de inscritos en el periodo comprendido entre el 2015-1 y el 2021-2 se obtuvo un error absoluto medio (MAE) de 14,85 y un valor-p de 0.08, esto bajo la prueba Shapiro-Wilks. A pesar del nivel de error que se presenta para los cálculos efectuados, Holt-Winters se convierte en un método de gran utilidad porque permite darle mayor importancia a los datos más recientes en donde pueden estar implícitos cambios significativos y no tanto a los históricos por su poca validez.The time series acquire a special attention in the different academic programmes since through them it is possible to understand the dynamics of potential students enrolled in these spaces. This article proposes the use of the Holt-Winters exponential smoothing method to estimate the number of students enrolled in the academic spaces offered by the Fundación Universitaria Los Libertadores so that the institution can have a better projection of the human, physical and technological resources that it will make available to its students. The results obtained for the ten subjects with the highest number of students enrolled in the period between 2015-1 and 2021-2 present a mean absolute error (MAE) of 14,85% and a p-value of 0.08 under the Shapiro-Wilks test. Despite the level of error in the calculations made, Holt-Winters is a very useful method because it allows greater importance to be given to the most recent data, where significant changes may be implicit, and less to historical data because of its low validity