415 research outputs found

    Isolation of 91 polymorphic microsatellite loci in the western mediterranean endemic carex helodes (Cyperaceae)

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    Premise of the study: Microsatellite primers were developed for Carex helodes (Cyperaceae), a western Mediterranean endemic that is locally distributed in southern Portugal and southwestern Spain and rare in northern Morocco. Methods and Results: One hundred nine nuclear microsatellite markers were developed using a shotgun pyrosequencing method, resulting in 91 polymorphic and 18 monomorphic loci when tested using 19 individuals sampled from five populations from Portugal, Spain, and Morocco. Loci averaged 3.23 alleles per locus (SD = 1.15). In a single population (Cortelha population, Portugal), the 34 most polymorphic loci showed a mean observed heterozygosity of 0.357 (SD = 0.292) and mean expected heterozygosity of 0.384 (SD = 0.255). Conclusions: Next-generation sequencing allowed us to develop a high number of genetic markers with levels of polymorphism adequate to study gene flow among populations. However, when genotyping the individuals within a population, we found low levels of variation

    Fruit cell culture as a model system to study cell wall changes during strawberry fruit ripening

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    Strawberry (Fragaria x ananassa, Duch.) fruit is characterized by its fast ripening and soft texture at the ripen stage, resulting in a short postharvest shelf life and high economic losses. It is generally believed that the disassembly of cell walls, the dissolution of the middle lamella and the reduction of cell turgor are the main factors determining the softening of fleshy fruits. In strawberry, several studies indicate that the solubilisation and depolymerisation of pectins, as well as the depolymerisation of xyloglucans, are the main processes occurring during ripening. Functional analyses of genes encoding pectinases such as polygalacturonase and pectate lyase also point out to the pectin fraction as a key factor involved in textural changes. All these studies have been performed with whole fruits, a complex organ containing different tissues that differ in their cell wall composition and undergo ripening at different rates. Cell cultures derived from fruits have been proposed as model systems for the study of several processes occurring during fruit ripening, such as the production of anthocyanin and its regulation by plant hormones. The main objective of this research was to obtain and characterize strawberry cell cultures to evaluate their potential use as a model for the study of the cell wall disassembly process associate with fruit ripening. Cell cultures were obtained from cortical tissue of strawberry fruits, cv. Chandler, at the stages of unripe-green, white and mature-red. Additionally, a cell culture line derived from strawberry leaves was obtained. All cultures were maintained in solid medium supplemented with 2.5 mg.l-1 2,4-D and incubated in the dark. Cell walls from the different callus lines were extracted and fractionated to obtain CDTA and sodium carbonate soluble pectin fractions, which represent polyuronides located in the middle lamella or the primary cell wall, respectively. The amounts of homogalacturonan in both fractions were estimated by ELISA using LM19 and LM20 antibodies, specific against demethylated and methyl-esterified homogalacturonan, respectively. In the CDTA fraction, the cell line from ripe fruit showed a significant lower amount of demethylated pectins than the rest of lines. By contrast, the content of methylated pectins was similar in green- and red-fruit lines, and lower than in white-fruit and leaf lines. In the sodium carbonate pectin fraction, the line from red fruit also showed the lowest amount of pectins. These preliminary results indicate that cell cultures obtained from fruits at different developmental stages differ in their cell wall composition and these differences resemble to some extent the changes that occur during strawberry softening. Experiments are in progress to further characterize cell wall extracts with monoclonal antibodies against other cell wall epitopes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Improving decision-making for sustainable hunting: regulatory mechanisms of hunting pressure in red-legged partridge

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    Knowledge about how hunting pressure is determined, and the relative efficacy of different mechanisms to regulate harvest, can help to improve the managers’ decision-making process. We developed a general framework about the decision-making process that regulates red-legged partridge (Alectoris rufa) hunting pressure in central Spain based on information from a focus group and individual interviews with game managers. We also used available information to compare the efficiency of different tools thus improving some decision steps. We evaluated the cost-effectiveness of different population monitoring methods as a way to reduce uncertainty on partridge availability to hunters. Additionally, we investigated the relationship between annual harvest and various regulatory mechanisms of partridge hunting pressure used in the study area to identify the most potentially useful one to limit annual take-off. Game managers usually set hunting pressure after a qualitative assessment on population abundance prior to the hunting season, but this decision was frequently modified during the course of the hunting season according to variations in catch or perceived abundance at that time. Our results showed that kilometric abundance indices (counting partridges from cars along line transects) was a simple cost-efficient and reliable estimate of partridge density (estimated by Distance sampling). A variety of regulatory mechanisms were used by managers. The variables that most affected annual harvest (in addition to partridge abundance) were the number of driven-shooting days, and hunter density in walked-up hunting days, suggesting that their adjustment will be the most efficient regulatory mechanisms. We conclude that adequate monitoring on population abundance should be a critical step for managers’ decision-making, and that a better understanding of the relative value of regulatory mechanisms, combining social and ecological approaches, would help improving our understanding of any human-mediated system, thus leading to better management recommendations.Work was supported by the European Commission (7th Framework Programme for R&D through project HUNT, 212160, FP7-ENV-2007-1); Consejería de Agricultura of JCCM; by the Ministerio de Ciencia y Tecnología (CGL2008-04282/BOS), and by CSIC (PIE 201330E105).Peer reviewe

    LIPSNN: A Light Intrusion-Proving Siamese Neural Network Model for Facial Verification

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    Facial verification has experienced a breakthrough in recent years, not only due to the improvement in accuracy of the verification systems but also because of their increased use. One of the main reasons for this has been the appearance and use of new models of Deep Learning to address this problem. This extension in the use of facial verification has had a high impact due to the importance of its applications, especially on security, but the extension of its use could be significantly higher if the problem of the required complex calculations needed by the Deep Learning models, that usually need to be executed on machines with specialised hardware, were solved. That would allow the use of facial verification to be extended, making it possible to run this software on computers with low computing resources, such as Smartphones or tablets. To solve this problem, this paper presents the proposal of a new neural model, called Light Intrusion-Proving Siamese Neural Network, LIPSNN. This new light model, which is based on Siamese Neural Networks, is fully presented from the description of its two block architecture, going through its development, including its training with the well- known dataset Labeled Faces in the Wild, LFW; to its benchmarking with other traditional and deep learning models for facial verification in order to compare its performance for its use in low computing resources systems for facial recognition. For this comparison the attribute parameters, storage, accuracy and precision have been used, and from the results obtained it can be concluded that the LIPSNN can be an alternative to the existing models to solve the facet problem of running facial verification in low computing resource devices

    Rhamnogalacturonase lyase gene downregulation in strawberry and its potential on mechanical fruit properties

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    Strawberry softening is one of the main factors that reduces fruit quality and leads to economically important losses. Textural changes during fruit ripening are mainly due to the dissolution of middle lamellae, a reduction in cell-to-cell adhesion and the weakening of parenchyma cell walls as a result of the action of cell wall modifying enzymes. Functional studies of genes encoding pectinase enzymes (polygalacturonase, pectate lyase and -galactosidase) support a key role of pectin disassembly in strawberry softening. Evidence that RG-I may play an important role in strawberry texture has been obtained from the transient silencing of a RG-lyase gene. Pectins are major components of fruit cell walls and highly dynamic polysaccharides, but due to their heterogeneity the precise relation between the structures and functions is incomplete. In this work, stable transgenic strawberry lines with a rhamnogalacturonate lyase gene (FaRGLyase1) down-regulated have been analyzed. Several transgenic lines showing more than 95% silencing of FaRGLyase1 displayed fruit firmness values higher than control. Cell walls from these lines were extracted and analyzed by ELISA and Epitope Detection Chromatography (EDC). This last technique is based on the detection of specific cell wall oligosaccharide epitopes and provides information on sub-populations of pectins containing homogalacturonan and RG-I domains, but also reveals potential links with other cell wall polysaccharides such as xyloglucan. The results obtained indicate that the silencing of FaRGLyase1 reduces degradation of RG-I backbones, but also homogalacturonan, in cell walls, especially in pectin fractions covalently bound to the cell wall. These changes contribute to the increased firmness of transgenic fruits.This research was supported by FEDER EU Funds and the Ministerio de Economía y Competitividad of Spain (grant reference AGL2014-55784-C2), a Marie Curie IEF within the 7th European Community Framework Programme (reference: PIEF-2013-625270) for SP and a FPI fellowship (BES-2015-073616) to support PR-V. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Thermal stability of Trancos montmorillonite pillared by alumina and alumina-lanthana

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    Se ha investigado el efecto de diversos tratamientos térmicos sobre la estructura porosa de una montmorillonita denominada Trancos que dan lugar a pilares de óxido de aluminio una, y óxido de aluminio-lantano, la otra. Para ello, se han usado las técnicas de difracción de rayos X, adsorción de nitrógeno, microscopía electrónica de barrido y espectroscopia infrarroja de transformada de Fourier. Los diagramas de difracción de rayos X de las muestras iniciales presentan espaciados basales ligeramente superiores a 18 Â. £1 óxido de lantano posee un efecto negativo sobre la estabilidad térmica de los pilares, pero aumenta la acidez de tipo Brönsted en la muestra no tratada.The effect of various thermal treatments on the porous structure of Trancos montmorillonite which give rise to pillars of alumina and alumina-lanthana was investigated by X-ray diffraction (XRD), nitrogen adsorption measurements, scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The XRD patterns of the original samples correspond to a basal spacing slightly higher 18 Â. The lanthana causes a negative effect on the thermal stability of the pillars but it enhances the Brönsted acidity of the fresh sample

    Case report: melioidosis imported from West Africa to Europe

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    We report the first case of imported melioidosis in Spain from a diabetic immigrant who visited West Africa during the rainy season. Because of the unusual presentation of this disease in Africa, clinical and microbiological diagnosis of imported melioidosis from this continent can be very elusive.S

    Efecto del silenciamiento de genes que codifican poligalacturonasas sobre el reblandecimiento del fruto de fresa asociado a la maduración

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    La degradación de las pectinas de la pared celular mediada por poligalacturonasas juega un papel clave en el reblandecimiento de la fresa. Así, el silenciamiento del gen FaPG1 incrementa la firmeza del fruto maduro y alarga su vida postcosecha. Además de FaPG1, en fresa se ha descrito otro gen que codifica una poligalacturonasa específica de maduración, FaPG2. Con el fin de profundizar en el papel de estos genes, se han obtenido plantas transgénicas con el gen FaPG2 silenciado (líneas BPG), así como plantas con FaPG1 y FaPG2 silenciados (líneas ABPG), obtenidas mediante retransformación de una línea antiFaPG1 (APG29) que mostraba un fuerte silenciamiento del gen y un incremento en la firmeza de fruto. Se obtuvieron 24 líneas BPG y 15 ABPG. Estas plantas, junto con la línea APG29 y controles sin transformar, fueron analizadas durante 3 años consecutivos. El 50% de las líneas BPG mostraron mayor firmeza de fruto rojo que el control sin transformar, aunque el incremento en firmeza fue similar al obtenido en la línea APG29. Todas las líneas dobles transformantes dieron frutos de mayor firmeza que el control, siendo los valores ligeramente superiores a los de la línea APG29 en alguna de ellas. A nivel de expresión, las líneas BPG seleccionadas mostraron un silenciamiento del gen FaPG2 que varió entre el 60-70%, e inesperadamente, un silenciamiento significativo de FaPG1, a pesar de la baja homología entre ambos genes. El silenciamiento de FaPG1 en las líneas ABPG fue superior al 95%; sin embargo, el silenciamiento de FaPG2 fue similar al obtenido en las plantas BPG. Estos resultados confirman el papel clave de las poligalacturonasas en el reblandecimiento de la fresa y sugieren la existencia de una regulación compleja en la expresión de ambos genes. Este trabajo ha sido financiado por el proyecto AGL2011-24814 y Fondos FEDERUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    La percepción del riesgo biológico en las prácticas clínicoasistenciales en los estudiantes de Grado de Enfermería de la Universidad de Barcelona

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    Podeu consultar la Vuitena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/66524Objetivo: Analizar la percepción del riesgo biológico de los estudiantes de Grado de Enfermería de la Universidad de Barcelona (UB) antes de iniciar sus prácticas clínicoasistenciales. Método: Estudio descriptivo transversal realizado en la Escuela de Enfermería de la UB en estudiantes de Grado de Enfermería matriculados en las asignaturas prácticas de segundo curso (Estancias Clínicas I) y de tercer curso (Estancias Clínicas II) durante el 2013-2014 (N=78). Variables: sociodemográficas, laborales, de formación, clínicas y referidas a la evaluación del riesgo biológico percibido. Se utilizó un instrumento de elaboración propia y la escala EDRP-T. Análisis estadístico: descriptivo y univariante para detectar si habían diferencias entre la percepción de riesgo biológico de los ítems de la escala EDRP-T y las variables sociodemográficas. Resultados: Los estudiantes sin formación práctica previa (Estancias Clínicas I) tenían menor percepción de conocimiento y menor percepción de daño derivado del riesgo biológico con respecto a los estudiantes con formación práctica previa (Estancias Clínicas II), (p=0.05 y p=0.04 respectivamente). Se detectó menor percepción del riesgo biológico en los estudiantes con experiencia laboral previa. Conclusión: La formación práctica y la experiencia laboral influyen en la percepción del riesgo biológico de los estudiantes de enfermería. Faltan estudios que relacionen la percepción de riesgo con el uso de las medidas de prevención durante su formación práctica y los accidentes de tipo biológicos sufridos
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