217 research outputs found
Unexpected consequences of a drier world: evidence that delay in late summer rains biases the population sex ratio of an insect
The complexity of animal life histories makes it difficult to predict the consequences of climate change on their populations. In this paper, we show, for the first time, that longer summer drought episodes, such as those predicted for the dry Mediterranean region under climate change, may bias insect population sex ratio. Many Mediterranean organisms, like the weevil Curculio elephas, become active again after summer drought. This insect depends on late summer rainfall to soften the soil and allow adult emergence from their underground refuges. We found that, as in many protandric species, more C. elephas females emerged later in the season. Male emergence timing was on average earlier and also more dependent on the beginning of late summer rainfall. When these rains were delayed, the observed weevil sex ratio was biased towards females. So far, the effects of global warming on animal sex ratios has been reported for temperature-dependent sex determination in reptiles. Our results show that rainfall timing can also bias the sex ratio in an insect, and highlight the need for keeping a phenological perspective to predict the consequences of climate change. We must consider not just the magnitude of the predicted changes in temperature and rainfall but also the effects of their timing.R.B. was funded by a contract of the Atracción de Talento Investigador Programme (Gobierno de Extremadura). A.M. was funded by a Juan de la Cierva contract (Ministerio de Educación). J.M.A. and M.H. were funded by the Spanish Research Council (CSIC). J.M.E. is contracted by the CREAF Institute. The work was financed by the projects: CONSOLIDER-MONTES CSD2008-00040 CONSOLIDER-MICINN, PII1C09-0256-9052 and PPII-2014-01-PJCCM ESF and CGL2008-00095/BOS MICINN.Peer Reviewe
Estudio y análisis económico de viabilidad de una planta de reciclaje de residuos de neumáticos y plásticos
Durante las últimas décadas la masiva fabricación de neumáticos y las dificultades para
hacerlos desaparecer una vez utilizados, constituye uno de los más graves problemas
medioambientales de los últimos años en todo el mundo.
Un neumático necesita grandes cantidades de energía para ser fabricado. Por poner un
ejemplo en nuestro país se generan cada año unas 314.000 toneladas de neumáticos
usados. El mercado español es el quinto país de la Unión Europea que más NFU produce
anualmente, tan sólo por detrás de Alemania (568.000 toneladas), Reino Unido (508.000),
Italia (421.000) y Francia (369.000).
Por otra parte en los últimos años ha aumentado de manera espectacular el consumo de
plástico de la sociedad moderna, que se estima que crece a un ritmo de un 4% anual a
nivel mundial y que se ha extendido no sólo en el campo de los envases sino que también
en el campo de la automoción, vivienda, vestido y todo tipo de bienes comunes.Nuestra motivación en este proyecto es analizar la viabilidad para la implantación de una
industria dedicada a la recuperación de neumáticos fuera de uso y de recuperación de
plásticos con el fin de que podamos evaluar la viabilidad del proyecto.
Con la implantación de esta industria volveríamos a introducir materiales reciclados en los
procesos de las industrias dedicadas al sector del plástico y del caucho con la finalidad de
crear puestos de trabajo y de preservar el medio ambiente
Sistematización y visibilización de experiencias agroecológicas en el Paraguay: investigaciones realizadas y difusión de resultados
A fin de organizar las ideas, en este documento se presentan los resultados de la investigación en tres partes. La primera, referida a artículos científicos resultantes de las investigaciones realizadas; la segunda, describe los aspectos más importantes del I Simposio Nacional de Agroecología realizado, de la Mesa Redonda sobre Agricultura familiar, agrobiodiversidad y servicios de extensión, bases de la sustentabilidad de las sociedades humanas en el marco del III Seminario Internacional de Ecología Humana; y de la difusión de los resultados en variados eventos; y en la tercera parte se presenta una Ficha de sistematización de experiencia agroecológica conforme a la plataforma del Observatorio de Soberanía Alimentaria y Agroecología (OSALA).CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI
Sistematización y visibilización de experiencias agroecológicas en el Paraguay: investigaciones realizadas en iniciación científica
El estudio ha planteado realizar un mapeo de las iniciativas agroecológicas, su distribución geográfica y vínculos existentes; sistematización de las experiencias agroecológicas en sus tres dimensiones: ecológico-productiva, socioeconómico y político-cultural; descripción de los productos, subproductos y Sistema Participativo de Garantía; difundir las experiencias agroecológicas en distintos ámbitos y de esta forma apuntar al fortalecimiento del Grupo de Investigación en Agroecología (GIA) de la FCA-UNA.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI
Ultrasound-assisted extraction as an easy-to-perform analytical methodology for monitoring ibuprofen and its main metabolites in mussels
Non-steroidal anti-infammatory drugs (NSAIDs) have been reported to be the main pharmaceutical class accumulated in
seafood. Among them, ibuprofen (IBU) is of special concern as it is used worldwide to treat common pain, does not require a
medical prescription, it is often taken in a high daily dose, and has been reported to cause potential adverse efects on aquatic
organisms. IBU is highly transformed into hydroxy- and carboxy-metabolites and/or degradation products generated not only
after its administration but also during wastewater treatment or in the environment. These compounds can be present in the
environment at higher concentrations than IBU and present higher toxicity. In this work, a low-cost and afordable routine
analytical method was developed and validated for the frst-time determination of IBU and its main metabolites in mussels.
The method is based on ultrasound-assisted extraction (UAE), clean-up by dispersive solid-phase extraction (d-SPE) and
analytical determination by liquid chromatography-tandem mass spectrometry. Box-Behnken experimental design was used
for method optimisation to better evaluate the infuence and interactions of UAE and d-SPE variables. Extraction recoveries
were in the range from 81 to 115%. Precision, expressed as relative standard deviation, was lower than 7%. Method detection
limits were in the range from 0.1 to 1.9 ng g−1 dry weight. The method was successfully applied to wild mussels.info:eu-repo/semantics/publishedVersio
Diversity in insect seed parasite guilds at large geographical scale: the roles of host specificity and spatial distance
[Aim]: Host specificity within plant-feeding insects constitutes a fascinating example of natural selection that promotes inter-specific niche segregation. If specificity is strong, composition of local plant parasitic insect guilds is largely dependent on the presence and prevalence of the preferred hosts. Alternatively, if it is weak or absent, historic and stochastic demographic processes may drive the structuring of insect communities. We assessed whether the species composition of acorn feeding insects (Curculio spp. guilds) and their genetic variation change geographically according to the local host community. [Location]: An 800 km transect across California, USA. [Methods]: We used DNA taxonomy to detect potential Curculio cryptic speciation and assessed intra-specific genetic structure among sampling sites. We monitored larval performance on different hosts, by measuring the weight of each larva upon emerging from the acorn. Our phylogenetic and spatial analyses disentangled host specificity and geographical effects on Curculio community composition and genetic structure. [Results]: DNA taxonomy revealed no specialized cryptic species. Californian Curculio spp. were sister taxa that did not segregate among Quercus species or, at a deeper taxonomic level, between red and white oaks. Curculio species turnover and intra-specific genetic differentiation increased with geographical distance among localities irrespective of local oak species composition. Moreover, larval performance did not differ among oak species or acorn sizes when controlling for the effect of the locality. [Main conclusions]: Historical processes have contributed to the structuring of acorn weevil communities across California. Trophic niche overlapped among species, indicating that ecologically similar species can co-exist. Acorn crop inter-annual variability and unpredictability in mixed oak forests may have selected against narrow specialization, and facilitated co-existence by means of an inter-specific time partitioning of the resources. Wide-scale geographical records of parasitic insects and their host plants are necessary to understand the processes underlying species diversity.This work was financed by the projects: CONSOLIDER-MONTES CSD2008-00040 MICINN, PII1C09-0256-9052JCCM and ESF, AGL2014-54739-R (MINECO), PPII-2014-01-PJCCM ESF and CGL2008-00095 ⁄ BOS (MICINN). A.M.was funded by a Juan de la Cierva contract and R.B. by acontract of the Atracción de Talento Investigador Programme (Gobierno de Extremadura TA13032). J.O. wasfunded by Severo Ochoa (SEV-2012-0262) and Ramón y Cajal (RYC-2013-12501) research fellowships.Peer reviewe
El cocotero (<i>Acrocomia totai</i>) en sistema agroecológico y sus múltiples usos en la comunidad de Paso Jhu, Paraguay
El cocotero (Acrocomia totai) tiene múltiples usos, crece naturalmente en diversas regiones de Paraguay y se combina bien con otros cultivos, sin embargo ha sido poco estudiado. La investigación describe la apropiación, transformación y usos de la planta por parte de familias rurales en el distrito de Piribebuy. Para ello se realizó un estudio descriptivo, cualitativo, con entrevistas a familias productoras y observación de los sistemas productivos.
Todas las familias del estudio indicaron apropiación, transformación y uso de la totalidad de la planta, es decir flor, fruto, hoja, tronco y raíz. El fruto es la parte más valorada, especialmente la almendra. El uso es tanto familiar, en alimentación humana y animal, medicina, combustible, construcción de vivienda e infraestructura productiva, como para generación de ingreso. La reinversión al sistema productivo se da con intervención antrópica y la especie se combina con otros rubros de la agricultura familiar.Coconut (Acrocomia totai) has multiple uses. Grows naturally in various regions of Paraguay and combines well with other crops, but has been little studied. The research describes the appropriation, transformation and use of the plant by rural families in Piribebuy district. A descriptive and qualitative research was done with farming families, by interviews and observation work. All families indicated appropriation, transformation and use of the whole plant, flower, fruit, leaf, stem and root. The fruit is the most valuable part, especially almonds.
The use is for human and animal food, medicine, fuel, housing construction and productive infrastructure, and for income generation. Reinvesting the production system it is given with human intervention and the species is combined with other areas of family farming.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale
El cocotero (<i>Acrocomia totai</i>) en sistema agroecológico y sus múltiples usos en la comunidad de Paso Jhu, Paraguay
El cocotero (Acrocomia totai) tiene múltiples usos, crece naturalmente en diversas regiones de Paraguay y se combina bien con otros cultivos, sin embargo ha sido poco estudiado. La investigación describe la apropiación, transformación y usos de la planta por parte de familias rurales en el distrito de Piribebuy. Para ello se realizó un estudio descriptivo, cualitativo, con entrevistas a familias productoras y observación de los sistemas productivos.
Todas las familias del estudio indicaron apropiación, transformación y uso de la totalidad de la planta, es decir flor, fruto, hoja, tronco y raíz. El fruto es la parte más valorada, especialmente la almendra. El uso es tanto familiar, en alimentación humana y animal, medicina, combustible, construcción de vivienda e infraestructura productiva, como para generación de ingreso. La reinversión al sistema productivo se da con intervención antrópica y la especie se combina con otros rubros de la agricultura familiar.Coconut (Acrocomia totai) has multiple uses. Grows naturally in various regions of Paraguay and combines well with other crops, but has been little studied. The research describes the appropriation, transformation and use of the plant by rural families in Piribebuy district. A descriptive and qualitative research was done with farming families, by interviews and observation work. All families indicated appropriation, transformation and use of the whole plant, flower, fruit, leaf, stem and root. The fruit is the most valuable part, especially almonds.
The use is for human and animal food, medicine, fuel, housing construction and productive infrastructure, and for income generation. Reinvesting the production system it is given with human intervention and the species is combined with other areas of family farming.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale
Interaction of genotype, water availability, and nitrogen fertilization on the mineral content of wheat grain
The aim of this study was to test the hypothesis that genetic variability is the key driver of mineral concentration in wheat grain in Mediterranean conditions. We grew 12 modern winter wheat varieties in semi-arid conditions and alkaline soils, in two consecutive years of contrasting water availability, and at three rates of N-fertilization: 64, 104, and 130 Kg N/ha. The genotype was the main driver of [Ca], [K], [Mg], and [S] in wheat grain, while the environmental conditions were more relevant for [Fe] and [Zn]. The nitrogen fertilization rate had little effect. The thousand-grain weight correlated negatively with the mineral concentration in the grain, revealing the importance of grain shape. CH-Nara grains were highly nutritious making this variety a potential source of germplasm. The knowledge gained from this study will guide future breeding and agronomic practices and guarantee food safety in the region in the advent of climate change.This work was supported in part by the Spanish projects PID2019-106650RB from the Ministerio de Ciencia e Innovación. FZR is the recipient of a research grant (FI-AGAUR) sponsored by the Agency for Management of University and Research Grants (AGAUR), in collaboration with the University of Barcelona. JLA acknowledges the support from ICREA Academia, the Autonomous Government of Catalonia, Spain
Algoritmos paralelos de memoria compartida que determinan el menor tama˜no de un ´arbol binario al refinar un simplex regular
En el ambito de la optimizacion global
basada en tecnicas de ramificacion y acotacion, cuando el espacio de busqueda es un n-sımplex regular es habitual utilizar como regla de division la biseccion por el lado mayor, debido a que garantiza la convergencia del algoritmo. Cuando la dimension del n-sımplex es mayor de 2 existen varios lados mayores
que pueden utilizarse para realizar la biseccion.
La eleccion del lado mayor influye en el tamaño del arbol binario completo que se genera. Una seleccion
eficiente del lado mayor puede reducir el coste computacional
de los algoritmos de ramificacion y acotacion
mencionados. En este estudio estamos interesados en conocer el tamaño del arbol o arboles mınimo(s). Para obtener una solucion de las instancias mas complejas del problema en un tiempo razonable es necesario el desarrollo de algoritmos paralelos. La complejidad del
problema es debida a la necesidad de analizar todas y cada una de las posibles combinaciones de selecciones de los distintos lados mayores en el refinamiento. Aquí se comparan la eficiencia de distintas propuestas de algoritmos paralelos para sistemas de memoria compartida.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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