150 research outputs found

    A new construction of Lagrangians in the complex Euclidean plane in terms of planar curves

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    We introduce a new method to construct a large family of Lagrangian surfaces in complex Euclidean plane by means of two planar curves making use of their usual product as complex functions and integrating the Hermitian product of their position and tangent vectors. Among this family, we characterize minimal, constant mean curvature, Hamiltonian stationary, solitons for mean curvature flow and Willmore surfaces in terms of simple properties of the curvatures of the generating curves. As an application, we provide explicitly conformal parametrizations of known and new examples of these classes of Lagrangians in complex Euclidean plane.Comment: 15 pages, 5 figure

    High-Throughput System for the Early Quantification of Major Architectural Traits in Olive Breeding Trials Using UAV Images and OBIA Techniques

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    The need for the olive farm modernization have encouraged the research of more efficient crop management strategies through cross-breeding programs to release new olive cultivars more suitable for mechanization and use in intensive orchards, with high quality production and resistance to biotic and abiotic stresses. The advancement of breeding programs are hampered by the lack of efficient phenotyping methods to quickly and accurately acquire crop traits such as morphological attributes (tree vigor and vegetative growth habits), which are key to identify desirable genotypes as early as possible. In this context, an UAV-based high-throughput system for olive breeding program applications was developed to extract tree traits in large-scale phenotyping studies under field conditions. The system consisted of UAV-flight configurations, in terms of flight altitude and image overlaps, and a novel, automatic, and accurate object-based image analysis (OBIA) algorithm based on point clouds, which was evaluated in two experimental trials in the framework of a table olive breeding program, with the aim to determine the earliest date for suitable quantifying of tree architectural traits. Two training systems (intensive and hedgerow) were evaluated at two very early stages of tree growth: 15 and 27 months after planting. Digital Terrain Models (DTMs) were automatically and accurately generated by the algorithm as well as every olive tree identified, independently of the training system and tree age. The architectural traits, specially tree height and crown area, were estimated with high accuracy in the second flight campaign, i.e. 27 months after planting. Differences in the quality of 3D crown reconstruction were found for the growth patterns derived from each training system. These key phenotyping traits could be used in several olive breeding programs, as well as to address some agronomical goals. In addition, this system is cost and time optimized, so that requested architectural traits could be provided in the same day as UAV flights. This high-throughput system may solve the actual bottleneck of plant phenotyping of "linking genotype and phenotype," considered a major challenge for crop research in the 21st century, and bring forward the crucial time of decision making for breeders

    The Clifford torus as a self-shrinker for the Lagrangian mean curvature flow

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    We provide several rigidity results for the Clifford torus in the class of compact self-shrinkers for Lagrangian mean curvature flow.Comment: 10 page

    Histological characterization of table olive fruit bruising cv. Manzanilla de Sevilla

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    Sin paginarActualmente el sector del olivar en España incluye dos subsectores claramente diferenciados por su aprovechamiento: el olivar de almazara y el de mesa o verdeo, cada uno con unas particularidades específicas que los diferencian, tales como variedades empleada s y técnicas de cultivo como la poda o la recolección. En los últimos años, la necesidad de optimizar los costes de producción ha generalizado la recolección mecanizada mediante brazos vibradores o máquinas cabalgadoras en explotaciones de olivar de aceite. Sin embargo, no se ha extendido de igual manera en plantaciones de aceituna de mesa, debido a los altos porcentajes de frutos dañados por los golpes que se producen durante la recolección mecanizada. El molestado, manchas oscuras en la parte externa del exocarpo de los frutos, hace referencia a los daños provocados en los frutos por los golpes durante la recolección, más notables en la recolección mecánica. Estas manchas deprecian el fruto a nivel comercial con el consecuente rechazo del consumidor. No todos los cultivares presentan la misma susceptibilidad al molestado. ‘Manzanilla de Sevilla’, variedad por excelencia de aceituna de mesa, es considerada sensible al molestado lo que dificulta su recolección por medios mecánicos. El Departamento de Ciencias Agroforestales de la Un iversidad de Sevilla empezó a trabajar en el año 2003 en un programa de mejora genética de olivo para mesa. Una de las líneas de trabajo dentro de este proyecto ha consistido en estudiar diferentes parámetros de calidad, entre los que se encuentra el molestado. En colaboración con el Instituto de Agricultura Sostenible-CSIC, se ha desarrollado una metodología para evaluar el mismo en aceituna de mesa. En este trabajo se describe anatómicamente el molestado en frutos frescos de ‘Manzanilla de Sevilla’, después de un golpe inducido, a los 30 minutos y 24 horas del impacto y fijados posteriormente con FAE (formalina, ácido acético, etanol del 95% y agua destilada (10:5:50:3 5 v/v/v/v)). Se han evaluado histológicamente los cambios (rupturas celulares y pérdida de grosor en paredes celulares) que se producen en el mesocarpo de las zonas dañadas. Las observaciones histológicas han revelad o diferencias en los daños para los dos momentos evaluados. La presencia de rupturas celulares y la pérdida de grosor de las paredes celulares, en las zonas dañadas, han sido más evidentes a las 24 horas tras el golpe.Currently olive growing in Spain includes two main industries: olive oil and table olives, each of which has its own peculiarities, such as different varieties and specific performance of cultivation techniques like pruning or harvesting. In recent years, due to the need of reducing production costs, mechanical harvesting using trunk shakers or straddle harvesters has become widespread in olive oil orchards. However, that is not the case in table olive plantations, due to the high percentage of fruit damaged by the impacts that take place during mechanical harvesting. The term fruit bruising, dark spots on the outside of the fruit exocarp, refers to the fruit damage caused by impacts during collection, most notably in mechanical harvesting. These spots decreases commercial fruit value, being rejected by the consumer. Not all cultivars have the same fruit bruise susceptibility. Manzanilla de Sevilla, Spanish leading table olive cultivar, is considered to be sensitive to bruising being therefore difficult to harvest by mechanical devices Researchers from the Departamento de Ciencias Agroforestales at the University of Seville, Spain, are working since 2003 on a table olive breeding program. One of the research lines within the program has been to study. different table olive quality parameters, including fruit bruising. An evaluation methodology is being developed to asses this phenomenon in collaboration with the Instituto de Agricultura Sostenible-CSIC. This paper describes anatomical changes related to fruit bruising in 'Manzanilla de Sevilla' fresh fruits after an induced impact. Bruised fruits were chemically fixed in FAE (formalin, acetic acid, 95% ethanol and distilled water (10:5:50:35 v/v/v/v)) 30 minutes and 24 hours after the impact. Histological changes (cell breakage, loss of cell wall thickness and higher colour intensity) produced in the mesocarp of the damaged areas have been evaluated. Histological observations revealed differences between the evaluated times. The presence of cell ruptures and the loss of thickness in the cell walls, in the damaged areas, has been most evident at 24 hours after the impact.Ministerio de Ciencia e Innovación y fondos FEDER, proyectos AGL2007-65184-C02-02 y AGL2009-0724

    Association between faecal pH and fat absorption in children with cystic fibrosis on a controlled diet and enzyme supplements dose

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    [EN] Background Despite treatment with pancreatic enzyme replacement therapy (PERT), patients with cystic fibrosis (CF) can still suffer from fat malabsorption. A cause could be low intestinal pH disabling PERT. The aim of this study was to assess the association between faecal pH (as intestinal pH surrogate) and coefficient of fat absorption (CFA). Additionally, faecal free fatty acids (FFAs) were quantified to determine the amount of digested, but unabsorbed fat. Methods In a 24-h pilot study, CF patients followed a standardised diet with fixed PERT doses, corresponding to theoretical optimal doses determined by an in vitro digestion model. Study variables were faecal pH, fat and FFA excretion, CFA and transit time. Linear mixed regression models were applied to explore associations. Results In 43 patients, median (1st, 3rd quartile) faecal pH and CFA were 6.1% (5.8, 6.4) and 90% (84, 94), and they were positively associated (p < 0.001). An inverse relationship was found between faecal pH and total fat excretion (p < 0.01), as well as total FFA (p = 0.048). Higher faecal pH was associated with longer intestinal transit time (p = 0.049) and the use of proton pump inhibitors (p = 0.009). Conclusions Although the clinical significance of faecal pH is not fully defined, its usefulness as a surrogate biomarker for intestinal pH should be further explored. Impact Faecal pH is a physiological parameter that may be related to intestinal pH and may provide important physiopathological information on CF-related pancreatic insufficiency. Faecal pH is correlated with fat absorption, and this may explain why pancreatic enzyme replacement therapy is not effective in all patients with malabsorption related to CF. Use of proton pump inhibitors is associated to higher values of faecal pH. Faecal pH could be used as a surrogate biomarker to routinely monitor the efficacy of pancreatic enzyme replacement therapy in clinical practice. Strategies to increase intestinal pH in children with cystic fibrosis should be targeted.We acknowledge the support of the MyCyFAPP Project consortium. We especially thank the participation and the effort of the patients involved in the study and their families. This work was fully funded by the European Union and the Horizon 2020 Research and Innovation Framework Programme (PHC-26-2014 call Self management of health and disease: citizen engagement and mHealth) under grant number 643806.Calvo-Lerma, J.; Roca-Llorens, M.; Boon, M.; Colombo, C.; De Koning, B.; Fornés-Ferrer, V.; Masip, E.... (2021). Association between faecal pH and fat absorption in children with cystic fibrosis on a controlled diet and enzyme supplements dose. Pediatric Research. 89(1):205-210. https://doi.org/10.1038/s41390-020-0860-3S205210891Turck, D. et al. ESPEN-ESPGHAN-ECFS guidelines on nutrition care for infants, children, and adults with cystic fibrosis. Clin. Nutr. 35, 557–577 (2016).Borowitz, D., Baker, R. 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    Single-cultivar extra virgin olive oil classification using a potentiometric electronic tongue

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    Label authentication of monovarietal extra virgin olive oils is of great importance. A novel approach based on a potentiometric electronic tongue is proposed to classify oils obtained from single olive cultivars (Portuguese cvs. Cobrançosa, Madural, Verdeal Transmontana; Spanish cvs. Arbequina, Hojiblanca, Picual). A meta-heuristic simulated annealing algorithm was applied to select the most informative sets of sensors to establish predictive linear discriminant models. Olive oils were correctly classified according to olive cultivar (sensitivities greater than 97%) and each Spanish olive oil was satisfactorily discriminated from the Portuguese ones with the exception of cv. Arbequina (sensitivities from 61% to 98%). Also, the discriminant ability was related to the polar compounds contents of olive oils and so, indirectly, with organoleptic properties like bitterness, astringency or pungency. Therefore the proposed E-tongue can be foreseen as a useful auxiliary tool for trained sensory panels for the classification of monovarietal extra virgin olive oils.This work was co-financed by FCT and FEDER under Program COMPETE (Project PEst-C/EQB/LA0020/2013)
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