1,060 research outputs found
Climate risks opposite to the introduction of a tropical crop (mango) in the Guadalhorce valley (Málaga)
El presente trabajo pretende demostrar que no es recomendable la introducción de un cultivo tropical como el mango (Mangifera indica) dentro del área mediterránea del valle del Guadalhorce (Málaga, España). Es un cultivo en expansión por su rentabilidad económica, pero es necesario atender a los posibles riesgos climáticos para su explotación (tras la gran inversión que requiere). Para justificar esta afirmación se presenta un estudio agroclimático realizado en las parcelas experimentales de la finca de IFAPA (Instituto de Investigación y Formación Agraria y Pesquera de Andalucía) de Churriana (Málaga). Los resultados se obtienen a través de los datos de una estación meteorológica y una modelización territorial a partir de herramientas de análisis espacial con SIG. Se tienen en cuenta las variables térmicas y los vientos como condicionantes principales de la aparición de la necrosis apical: patología mortal para el mango.This work tries to demonstrate that is not recommendable to bring a tropical crop like the mango (Mangifera indica) in a Mediterranean area as Guadalhorce valley (Málaga, Spain). This crop is getting an expansion because of its high economic profitability, but it is necessary to pay attention in possible climatic risks before its exploitation (because it needs high capital investment). Justifying it, we present an agroclimatic study carried out in experimental plots of IFAPA (Instituto de Investigación y Formación Agraria y Pesquera de Andalucía) at Churriana (Málaga, Spain), obtaining results by means of a meteorological workstation data and a territorial model using spatial analyst tools with GIS. Thermic variables and winds have been considered as determining factors for appearance of apical necrosis: deadly disease for the mango
Solar disinfection as a direct tertiary treatment of a wastewater plant using a photochemical-photovoltaic hybrid system
This work evaluates the SolWat hybrid system for solar water disinfection and photovoltaic energy generation, for its implementation in tertiary treatment plants, using real wastewater directly from the effluent after its secondary treatment. Solar disinfection of E. coli, Enterococcus faecalis and Clostridium perfringens microorganisms was evaluated over the course of a complete year. Four experiments in batch mode were conducted in autumn, winter, spring and summer, and microbiological and physicochemical parameters were analysed. In addition, the kinetics of solar disinfection during 4 h were analysed, and the dose of lethal ultraviolet radiation for microorganisms established. Results showed that E. coli, Enterococcus faecalis and C. perfringens did not complete total bacterial inactivation after 4 h of treatment in the SolWat system, but that the inactivation levels achieved were sufficient as to allow for the reuse of water for various uses (urban, agricultural, industrial, etc.). Clostridium perfringens continued to be the most resistant bacteria vs. E. coli and Enterococcus faecalis. The total photovoltaic energy production in the hybrid system compared to the reference system was the same, generating both the SolWat module and the reference module identical electrical power due to the compensating effect of module water cooling vs. radiation losses
Vineyards assessed under a biophysical approach: findings from the biohydrology and TERRAenVISION meetings
During the Biohydrology 2019 (24-27 July 2019, Valencia, Spain) and TERRAenVISION 2019 (2-7 September 2019, Barcelona, Spain) meetings, the scientific sessions joined reputed scientists around the world. Innovative debates during these scientific sessions about vineyards focused on the use of new technologies to assess soil erosion and nutrient losses, benefits or damages generated by tillage, the use of cover crops, and the introduction of organic farming. Among all the high-quality posters and oral presentations in these 2 abovementioned conferences, 3 groups from different countries with an extended list of publications decided to publish their new findings on the special issue: Vineyards Assessed Under a Biophysical Approac
Long‑term changes in rainfed olive production, rainfall and farmer's income in Bailén (Jaén, Spain)
AbstractEconomic, social, and climatic conditions affect agricultural production. Those changes are relevant to the rainfed agricultural areas of the Mediterranean Belt, including Spain—the largest producer of olive oil in the world. However, little is known about the effect of the climate on olive production and farmer income. In this study, the correlation between changes in rainfall and total olive production was examined using a long-term dataset (28 years) on conventional rainfed production and tillage soil management. The dataset focused on different olive groves in the municipality of Bailén (Jaén, Andalusia) that have been owned by the same farmer since 1966. The province of Jaén is the region of Spain with the highest production of olive oil and the largest area of olive groves. The data included annual rainfall, production per plot and the price of olives. After calculating missing data to complete the rainfall series, pairwise correlation analysis with nonparametric Spearman's rank coefficients and principal component analysis were used to process the data. The results showed that higher production coincided with increased rainfall during August and December. Therefore, we concluded that the impact of rainfall on olive production is variable and depends on drought intensity and the monthly rainfall distribution. An economic study showed that farmer income was highly dependent on the seasonal distribution of the rainfall among other factors such as the price of olives. Farmer income was low during drought periods, indicating that rainfed agriculture is perceived by farmers as unsustainable due to the resulting highly variable income. This study could help to prevent risks to food security in the future. We recognise that other key factors have also been important influences on the fluctuations in olive production over the years, such as soil properties and plant status. However, cultivating olives without irrigation—depending only on the total rainfall amount and rainfall intensity to supply all of the water consumed by the plants—is very risky too. This research demonstrates that the subsistence of Mediterranean rainfed olive farmers can be highly dependent on the rainfall conditions
Critéres d´evaluation des risques avec géomorphologique a travers des unites de diasnostic dans le territoire de Casapalma (Guadalhorce Valley, Espagne)
El presente trabajo muestra los resultados de una metodología combinada para la zonificación de la peligrosidad con orígenes geomorfológicos sobre un territorio. Para este propósito, se han utilizado como herramientas principales las unidades de diagnóstico y las técnicas de evaluación multicriterio con Sistemas de Información Geográfica (SIG). Normalmente estas técnicas no han sido aplicadas en el medio mediterráneo. Por lo tanto, para este caso, se ha llevado a cabo como ejemplo un estudio en el área del Valle del Guadalhorce (provincia de Málaga, España) con un paisaje marcado por un sistema de terrazas fluviales y glacis. Con dichas técnicas, se han obtenido cinco categorías de peligrosidad con origen geomorfológico (1=muy poca; 5= muy alta). De las 1872.68 ha del área de estudio, el 51.93% se encuentra en intervalos de peligrosidad alta debido a: (1) problemas de arroyada concentrada en las laderas; (2) actividad erosiva espasmódica del cauce principal y sus afluentes; (3) inestabilidad por movimientos en masa de áreas compuestas por arcillas expansivas con procesos vérticos.This paper presents the results of a combined methodology for zoning the dangerousness with geomorphological origins on a territory. For this purpose, diagnostic units and techniques of multicriteria analysis with Geographic Information Systems (GIS) are used as main tools for the analysis. Usually these types of studies are not applied with this methodology in the Mediterranean environment. Thus, in this case, this application is carried out as example in one part of the Guadalhorce Valley (Province of Malaga) with fluvial terraces and glacis landscapes. In this way, using this methodological sequence, five categories of dangerousness (1 = very low; 5 = very high) are obtained. With 1872.68 ha, 51.93% has high dangerousness with geomorphological origins. This situation is caused by: (1) concentrate runoff problems; (2) spasmodic erosive activity of the main stream and its tributaries; (3) landslides in areas with expansive clays and vertic processes.Cet article présente les résultats d'une combinée méthodologie pour zonage de territoire avec niveaux de danger avec origines géomorphologiques. À cette fin, ont été utilisés comme les principaux des unités de diagnostic et techniques d'évaluation multi-critères avec les Systèmes d'Information Géographiques (SIG). Habituellement, ces types d'études ne sont pas appliqués avec cette méthodologie dans l'environnement méditerranéen. Par conséquent, dans ce cas, il a été considéré, par exemple, une étude dans la zone de Valle del Guadalhorce (Málaga, Espagne) avec un paysage marqué par un système de terrasses fluviales et glacis. Avec ces techniques, on a obtenu cinq catégories de danger avec l'origine géomorphologique (1 = très peu, 5 = très élevé). With 1872.68 ha, 51.93% has high dangerousness with geomorphological origins. Avec 1872,68 ha, 51,93% ont une forte dangerosité avec des origines géomorphologiques. Cette situation est causée par: (1) se concentrer problèmes de ruissellement; (2) L'activité érosive spasmodique du courant principal et de ses affluents; (3) glissements de terrain dans les zones à argiles gonflantes et les processus vertic
Social media technologies: a waste of time or a good way to learn and improve technological competences?
Purpose – The purpose of this study is to deepen understanding of the effects of using social media
technologies to acquire technological knowledge and organizational learning competences, of
technological knowledge competences on organizational learning and finally of organizational learning
on organizational performance.
Design/methodology/approach – The study was performed by analyzing data from a sample of 197
technology firms located in Spain. The hypotheses were tested using a structural equations model with
the program LISREL 8.80.
Findings – This study’s conceptual framework is grounded in complexity theory – along with dynamic
capabilities theory, which complements the resource-based view. The study contributes to the literature
by proposing a model that reflects empirically how business ecosystems that use social media
technologies enable the development of interorganizational and social collaboration networks that
encourage learning and development of technological knowledge competences.
Research limitations/implications – It would be interesting for future studies to consider other
elements to conceptualize and measure social media technologies, including (among others)
significance of the various tools used and strategic integration. The model might also analyze other
sectors and another combination of variables.
Practical implications – The results of this study have several managerial implications: developing
social media technologies and interorganizational social collaboration networks not only enables the
organizational learning process but also encourages technological knowledge competences. Through
innovation processes, use of social media technologies also contributes to strengthening companies’
strategic positioning, which ultimately helps to improve firms’ organizational performance.
Social implications – Since social media technologies drive information systems in contemporary
society (because they enable interaction with numerous agents), the authors highlight the use of
complexity theory to develop a conceptual framework.
Originality/value – The study also deepens understanding of the connections by which new experiential
learning contributes to the generation of coevolutionary adaptive business ecosystems and digital
strategies that enable development of interorganizational and social collaborative networks through
technological knowledge competences. Only after examining the impact of socialmedia technologies on
organizational performance in prior literature, did the authors underscore that both quantity and
frequency of social media technology use are positively related to improvement in knowledge processes
that lead to employees’ creation and acquisition of new metaknowledge.Excellence Unit "Advanced Research in Economics and Business" of the University of Granada (Spain)Andalusian Regional Government B-SEJ-042-UGR18
A-SEJ-192-UGR20
P20_0056
Extracción de metales pesados presentes en cenizas volantes mediante microorganismos
El presente Proyecto Fin de Carrera trata sobre el uso de microorganismos (tanto unicelulares como no) para la biolixiviación de metales pesados. Los metales pesados se encuentran en las cenizas producidas en una planta de biomasa que usa madera como combusible. El alto contenido en metales pesados de la fracción volante impide que ésta se pueda usar posteriormente tanto en la industria cementera como de abono para el campo. El objetivo de este PFC es la eliminación o reducción de la concentración de dichos metales de cara a que su posterior utilización sea posible. Una vez libres las cenizas de dichos metales, se mezclarán en una proporción a determinar con cenizas sedimentarias, que, en general, presentan concentraciones muy bajas de elementos tóxicos y se pelletizarán para facilitar su transporte y posterior distribución. Los microorganismos empleados han sido utilizados anteriormente como biolixiviantes para purificar, por ejemplo, tierra situada cerca de vertederos o agua contaminada. Tienen distintos mecanismos de funcionamiento. Por ejemplo, en el Aspergillus niger los metales se adhieren a su superficie, mientras que otros, como el Acidithiobacillus thiooxidans, oxidan los metales. Presentan un medio económico y ecológico para la extracción de metales. Para la biolixiviación se emplean distintos microorganismos y se optimiza el pH de trabajo para conseguir el máximo rendimiento. El procedimiento a seguir consta de varios pasos. Primero se disuelven las cenizas en agua destilada y se llevan a distintos pHs, de 1 a 7, hasta que el pH se mantenga estable. Tras filtrar la disolución, el procedimiento de biolixiviación se lleva a cabo con la solución. Tras el proceso, se controla si los microorganismos siguen estando vivos a no. Una vez separada la biomasa, las muestras se miden con ICP-OES. Se comparan los distintos métodos y pHs hasta encontrar el óptimo. Por otra parte, se comienza el proceso de pelletar. Para ello se dispone de una máquina pelletizadora, un mezclador y un distribuidor. Aquí las variables a optimizar son la velocidad de giro de la máquina y la cantidad de humedad que tendrán los pellets
Novel Bread Wheat Lines Enriched in Carotenoids Carrying Hordeum chilense Chromosome Arms in the ph1b Background
The use of crop wild relative species to improve major crops performance is well established. Hordeum chilense has a high potential as a genetic donor to increase the carotenoid content of wheat. Crosses between the 7Hch H. chilense substitution lines in wheat and the wheat pairing homoeologous1b (ph1b) mutant allowed the development of wheat-H. chilense translocation lines for both 7Hchα and 7Hchβ chromosome arms in the wheat background. These translocation lines were characterized by in situ hybridization and using molecular markers. In addition, reverse phase chromatography (HPLC) analysis was carried out to evaluate the carotenoid content and both 7Hchα∙7AL and 7AS∙7Hchβ disomic translocation lines. The carotenoid content in 7Hchα∙7AL and 7AS∙7Hchβ disomic translocation lines was higher than the wheat-7Hch addition line and double amount of carotenoids than the wheat itself. A proteomic analysis confirmed that the presence of chromosome 7Hch introgressions in wheat scarcely altered the proteomic profile of the wheat flour. The Psy1 (Phytoene Synthase1) gene, which is the first committed step in the carotenoid biosynthetic pathway, was also cytogenetically mapped on the 7Hchα chromosome arm. These new wheat-H. chilense translocation lines can be used as a powerful tool in wheat breeding programs to enrich the diet in bioactive compounds.This work was supported by the ERC Starting Grant 243118 (http://www.ias.csic.es/ercstg-superwheatcrops/).Peer reviewe
Stability and Thermal Properties Study of Metal Chalcogenide-Based Nanofluids for Concentrating Solar Power
Nanofluids are colloidal suspensions of nanomaterials in a fluid which exhibit enhanced thermophysical properties compared to conventional fluids. The addition of nanomaterials to a fluid can increase the thermal conductivity, isobaric-specific heat, diffusivity, and the convective heat transfer coefficient of the original fluid. For this reason, nanofluids have been studied over the last decades in many fields such as biomedicine, industrial cooling, nuclear reactors, and also in solar thermal applications. In this paper, we report the preparation and characterization of nanofluids based on one-dimensional MoS2 and WS2 nanosheets to improve the thermal properties of the heat transfer fluid currently used in concentrating solar plants (CSP). A comparative study of both types of nanofluids was performed for explaining the influence of nanostructure morphologies on nanofluid stability and thermal properties. The nanofluids prepared in this work present a high stability over time and thermal conductivity enhancements of up to 46% for MoS2-based nanofluid and up to 35% for WS2-based nanofluid. These results led to an increase in the efficiency of the solar collectors of 21.3% and 16.8% when the nanofluids based on MoS2 nanowires or WS2 nanosheets were used instead of the typical thermal oil
Revisión sistemática: El uso de benzodiacepinas en mayores de 65 años y el riesgo de desarrollar demencia
Resumen Introducción: El envejecimiento de la población, debido al aumento en la esperanza de vida, supone un aumento en la probabilidad de padecer múltiples afecciones. La demencia, es la principal causa de discapacidad y dependencia en las personas mayores. Otras enfermedades como el insomnio, la ansiedad y los síntomas depresivos, son frecuentes en los ancianos y pueden ser síntomas precursores de la demencia. Los fármacos más utilizados para tratar este tipo de afecciones son las benzodiacepinas. El aumento de población envejecida y del uso crónico de fármacos como las benzodiacepinas, ha supuesto una alarma sanitaria, debido a los efectos adversos como el aumento de deterioro cognitivo entre los pacientes que las usan.Objetivo: Revisar la literatura científica con el fin de identificar, resumir y analizar los aspectos importantes de la información existente sobre el riesgo de padecer demencia entre la población adulta mayor de 65 años que consume benzodiacepinas.Metodología: Se ha llevado a cabo un estudio de revisión sistemática según las directrices The Cochrane Collaboration con su manual “Manual Cochrane de revisiones sistemáticas de intervenciones”, así como la Declaración “Preferred Reporting Items for Systematic Reviews and MetaAnalyses (PRISMA)”. Se ha realizado una búsqueda en las bases de datos PUBMED, SCOPUS, SCIENCE DIRECT, WEB OF SCIENCE y DIALNET PLUS sobre el riesgo de padecer demencia en población mayor de 65 años,consumidora de benzodiacepinas.Resultados: Se incluyeron 15 artículos que analizaban el uso de benzodiacepinas y el riesgo de desarrollar demencia en población mayor de 65 años. Concluyendo que prácticamente la mitad de los artículos seleccionados han encontrado una asociación entre el uso de BZDs y el riesgo de desarrollar demencia y la otra mitad no, por lo que hay heterogeneidad en los resultados, esto puede ser debido a la metodología utilizada por los diferentes autores de los estudios seleccionados.Conclusiones: Debido a la heterogeneidad de los resultados no podemos asegurar que el consumo de benzodiacepinas en una población mayor de 65 años aumente el riesgo de padecer demencia. Sin embargo, sí que sabemos que un uso prolongado de benzodiacepinas supone un mayor riesgo de presentar deterioro cognitivo. En las guíasde práctica clínica no se recomienda el uso prolongado de BZDs en adultos mayores ya que, es más difícil la deshabituación. Por otra parte, sería necesario realizar pruebas neurológicas en la población adulta para detectar de una manera temprana la demencia o por lo menos el deterioro cognitivo, así como, evaluar las alternativas terapéuticas a este tipo de fármacos.<br /
- …