Acuerdo de asociación Centroamérica-Unión Europea: evaluación utilizando equilibrio general computable y equilibrio parcial

Incluye Bibliografí

Detection of glaucoma using three-stage training with EfficientNet

[EN] This paper sets forth a methodology that is based on three-stage-training of a state-of-the-art network architecture previously trained on Imagenet, and iteratively finetuned in three steps; freezing first all layers, then re-training a specific number of them and finally training all the architecture from scratch, to achieve a system with high accuracy and reliability. To determine the performance of our technique a dataset consisting of 17.070 color cropped samples of fundus images, and that includes two classes, normal and abnormal, is used. Extensive evaluations using baselines models (VGG16, InceptionV3 and Resnet50) are carried out, in addition to thorough experimentation with the proposed pipeline using variants of EfficientNet and EfficientNetV2. The training procedure is described accurately, putting emphasis on the number of parameters trained, the confusion matrices (with analysis of false positives and false negatives), accuracy, and F1-score obtained at each stage of the proposed methodology. The results achieved show that the intelligent system presented for the task at hand is reliable, presents high precision, its predictions are consistent and the number of parameters needed to train are low compared to other alternatives.This work is supported by the HK Innovation and Technology Commission (InnoHK Project CIMDA), the HK Research Grants Council (Project CityU 11204821) and City University of Hong Kong (Project 9610034). We acknowledge the support of Universitat Politècnica de València; R&D project PID2021-122580NB-I00, funded by MCIN/AEI/ 10.13039/501100011033 and ERDF.De Zarzà, I.; De Curtò, J.; Tavares De Araujo Cesariny Calafate, CM. (2022). Detection of glaucoma using three-stage training with EfficientNet. Intelligent Systems with Applications. 16:1-10. https://doi.org/10.1016/j.iswa.2022.2001401101

Response of fish communities in rivers subjected to a high sediment load

Erosion and sediment yield are a significant problem in the Guadalquivir River basin. Such phenomena are largely driven by a land use devoted to intensive cultivation of olive trees, with a large socioeconomic influence in Andalusia. This sediment overload in rivers causes serious impacts on all fluvial ecosystem components. In this study we assess the chronic effect of sediment yield on fish communities at 104 river sites located in two different sub-catchments ? the Bembézar and Guadajoz rivers ? both with different lithological composition and erosion rates. Sediment yield was estimated using a semi-quantitative Factorial Score Model (FSM), developed specifically for Spanish rivers. The fish populations of both basins were evaluated in composition and abundances by the study of Fernández-Delgado et al., 2014. The influence of sediment yield on the fish community was analyzed using General Additive Models. The sediment yield was higher in the Guadajoz basin (921 T/Km2 per year) than in Bembézar (701 T/Km2 per year). In the former, fish communities were poorer in both fish density and diversity, with Luciobarbus sclateri as the only substantially present species and a significant relationship between sediment yield and load, and fish density. In contrast, in the Bembézar basin, sediment yield was correlated with total fish density, including Luciobarbus sclateri, Pseudochondrostoma willkommii, Cobitis paludica, Iberochondrostoma lemmingii, Anaecypris hispanica, and Cyprinus carpio. Intermediate values of sediment yield led to maximum densities, while those higher decreased the density of these species

Trade agreements by Colombia, Ecuador and Peru with the United States: effects on trade, production and welfare

The Computable General Equilibrium model, based on the Global Trade Analysis Project (GTAP) model, is used to evaluate the impact of separate bilateral free trade agreements by Colombia, Ecuador and Peru with the United States of America (USA). As the Andean Trade Promotion and Drug Eradication Act (ATPDEA) is to expire shortly, a number of different scenarios have been analyzed: full liberalization, liberalization excluding sensitive products and non-conclusion of agreements. Signature of the agreements would lead to a widespread increase in trade among the negotiating countries to the detriment of their Andean partners. While the effects on welfare would benefit only the United States and Peru, from the capital accumulation standpoint they are clearly positive for all countries. Research shows that, while these agreements would not be enough on their own to trigger a process of sustained development, an active economic and social policy could usefully tap their potential.Treaties, Free trade, Trade negotiations, Social welfare, Economic analysis, Andean region, United States

Estudio de la filtración apical de cuatro cementos de obturación

Los autores estudian in vitro la microfiltración apical con cuatro cementos de obturación, mediante la utilización de un colorante y técnicas de diafanización. Analizan dos cementos a base de hidróxido de calcio, y uno de ionómero de vidrio, comparándolos con un cemento clásico a base de óxido de zinc-eugenol. La filtración apical del cemento sellador Apexit fue significativamente superior a la de los cementos Sealapex y Endomethasone. No se observaron diferencias significativas entre los demás cementos (Ketac-Endo respecto a los demás, y Sealapex respecto a Ketac-Endo y Endomethasone). Se discute la necesidad de estandarizar las variables que se presentan en este tipo de trabajos, para poder comparar datos de diferentes estudios. Asimismo, se cuestiona la validez de los estudios de filtración apical de cara a evaluar los cementos selladores y de su correlación con la indicación clínica de los mismos

Study of the influence of the needle lift on the internal flow and cavitationphenomenon in diesel injector nozzles by CFD using RANS methods

It is well known that cavitation phenomenon in diesel injector nozzles has a strong influence on the internal flow during the injection process and spray development. However, its influence on the flow during needle opening and closing remains still unclear due to the huge difficulties related to performing experiments at partial needle lifts. In this paper, an extended computational study has been performed in a multi-hole nozzle modeling 10 different fixed needle lifts. The internal flow has been modeled with a continuum nozzle flow model that considers the cavitating flow as a homogeneous mixture of liquid and vapour. Due to high Reynolds numbers, turbulence effects have been taken into account by RANS methods using a RNG k e model. Firstly, the code has been validated against experimental data at full needle lift conditions in terms of mass flow, momentum flux and effective velocity, showing a fairly good agreement with experimental results. Once the code has been validated, it has been possible to study in depth the internal nozzle flow and its characteristics at the outlet at different partial needle lifts. Nevertheless, not only the main flow features have been explained, but also the cavitation appearance and the turbulence development, which present huge differences between the different needle lifts simulated.The authors wish to acknowledge the Generalitat Valenciana for the financial support through the project GVA PROMETEO CMT 2010 (reference code: GR001/2009/00167539).Salvador, FJ.; Martínez López, J.; Caballer Fernández, M.; Alfonso Laguna, CD. (2013). Study of the influence of the needle lift on the internal flow and cavitationphenomenon in diesel injector nozzles by CFD using RANS methods. Energy Conversion and Management. 66:246-256. https://doi.org/10.1016/j.enconman.2012.10.0112462566

On the Hamilton-Jacobi Theory for Singular Lagrangian Systems

We develop a Hamilton-Jacobi theory for singular lagrangian systems using the Gotay-Nester-Hinds constraint algorithm. The procedure works even if the system has secondary constraints.Comment: 36 page

Late cenozoic identation/escape tectonics in the eastern Betic Cordilleras and its consequences on the Iberian foreland

13 páginas, 5 figuras.[ES] La estructuración del cuadrante SE de la Península Ibérica (Béticas orientales y antepaís Ibérico), desde el Messiniense hasta la actualidad, ha sido el resultado de una serie compleja de eventos deformativos, relacionados con la actividad de una megazona de cizalla NNE-SSO en el SE de las Cordilleras Béticas (zona de cizalla Trans-Alborán-Palomares; TAPSZ). La deformación a lo largo de esta zona de cizalla se caracteriza por dos escenarios secuenciales diferentes: 1) períodos de concentración de esfuerzos, asociados con un frenado momentáneo del movimiento a lo largo de la TAPSZ, y con procesos de identación dirigidos hacia el NO, y 2) períodos de disipación de esfuerzos, que serían el resultado del escape lateral de bloques en forma de cuña, y del movimiento transcurrente renovado a lo largo de la TAPSZ. Estos eventos han generado campos de esfuerzos en el antepaís Ibérico, con una serie de consecuencias tales como el vulcanismo alcalino de Calatrava y Cofrentes, zonas de protorift, modificaciones de directrices estructurales previas, levantamientos/abombamientos localizados, y cambios en el régimen sedimentario de algunas cuencas.[EN] The structuration of the southeastern quarter of the Iberian Peninsula (eastern Betics and Iberian foreland), since Messinian time, was the result of a series of complex deformational events, as related to a major NNE-SSW sinistral shear zone disrupting the southeasternmost part of the Betic cordilleras (Trans-Alborán-Palomares shear zone; TAPSZ). Deformation along this shear zone was characterized by two differentiated and sequential scenarios: 1) periods of stress-build-up associated to momentary slip-obstruction along the TAPSZ, involving NW-directed indentation of the southeastern Iberian domain, and 2) periods of stress-release resulting from the lateral escape of wedge-shaped blocks, thus allowing full-scale strike-slip displacements along the TAPSZ. These events imposed compressional stress fields on the Iberian foreland, with a series of consequences such as alkaline volcanism in Calatrava and Cofrentes, protorift zones, changes in previous structural trends, localized uplift/doming processes, and changes in the sedimentary records of sorne basins.Financial support was provided by the Dirección General de la Política Científica through Project n.O PB87-0372.Peer reviewe

High-fat diet feeding alters metabolic response to fasting/non fasting conditions. Effect on caveolin expression and insulin signalling

<p>Abstract</p> <p>Background</p> <p>The effect of food intake on caveolin expression in relation to insulin signalling was studied in skeletal muscle and adipocytes from retroperitoneal (RP) and subcutaneous (SC) adipose tissue, comparing fasted (F) to not fasted (NF) rats that had been fed a control or high-fat (HF) diet for 72 days.</p> <p>Methods</p> <p>Serum glucose was analysed enzymatically and insulin and leptin by ELISA. Caveolins and insulin signalling intermediaries (IR, IRS-1 and 2 and GLUT4) were determined by RT-PCR and western blotting. Caveolin and IR phosphorylation was measured by immunoprecipitation. Data were analysed with Mann-Whitney U test.</p> <p>Results</p> <p>High-fat fed animals showed metabolic alterations and developed obesity and insulin resistance. In skeletal muscle, food intake (NF) induced activation of IR and increased expression of IRS-2 in control animals with normal metabolic response. HF animals became overweight, hyperglycaemic, hyperinsulinemic, hyperleptinemic and showed insulin resistance. In skeletal muscle of these animals, food intake (NF) also induced IRS-2 expression together with IR, although this was not active. Caveolin 3 expression in this tissue was increased by food intake (NF) in animals fed either diet. In RP adipocytes of control animals, food intake (NF) decreased IR and IRS-2 expression but increased that of GLUT4. A similar but less intense response was found in SC adipocytes. Food intake (NF) did not change caveolin expression in RP adipocytes with either diet, but in SC adipocytes of HF animals a reduction was observed. Food intake (NF) decreased caveolin-1 phosphorylation in RP but increased it in SC adipocytes of control animals, whereas it increased caveolin-2 phosphorylation in both types of adipocytes independently of the diet.</p> <p>Conclusions</p> <p>Animals fed a control-diet show a normal response to food intake (NF), with activation of the insulin signalling pathway but without appreciable changes in caveolin expression, except a small increase of caveolin-3 in muscle. Animals fed a high-fat diet develop metabolic changes that result in insulin signalling impairment. In these animals, caveolin expression in muscle and adipocytes seems to be regulated independently of insulin signalling.</p

Numerical analysis of the manufacturing processes of a mock-up of the ITER NHF First Wall Panel

The objective of ITER is to build a new Tokamak, with the goal of demonstrating the scientific and technical feasibility of fusion power. The First Wall Panels are the inner component of the reactor, built with different materials that must support high heat flux levels inside the vacuum vessel. The manufacturing processes of the First Wall are a complex procedure including bending, hipping and cutting procedures which, in general, lead to residual stresses and distortions of the fabricated component. In this work, the analysis of the thermo-mechanical response of a simplified prototype of the ITER NHF First Wall Panel is presented from the numerical point of view. The experimental procedure within each phase of the whole manufacturing process is described. Residual stresses and distortions have been measured and analyzed. The numerical simulation of the manufacturing process includes the description of the main hypothesis, the applied loads and the boundary conditions assumed at every stage of the process. Special attention is paid to the simulation of machining and cutting by means of an&nbsp;ad-hoc&nbsp;element deactivation strategy. The numerical results are compared with the experimental evidence to show the prediction capability and the limitations of the proposed numerical model