974 research outputs found

    A virtue-based model of leadership education.

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    This article presents a theoretical justification and a proposal that seeks to educate university students in leadership through virtues and personal competencies. A distinction is offered between virtues and competencies without opposing them. Subsequently, a leadership education model based on virtues and personal competencies is offered. This proposal applies the Aristotelian-Thomistic tradition of education in virtues considering the contributions of psychology and leadership theory. The leadership model includes eight competencies linked to the cardinal virtues, which are grouped into three domains: understanding reality, relating to others and dedication to the task. Finally, some guidelines for the further development of assessment instruments and for leadership education of university students are offered.post-print830 K

    Sliding wear behavior of WC-Co-Cr3C2-VC composites fabricated by conventional and non-conventional techniques

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    [EN] The present work aims are to study the dry sliding wear behavior of WC-12 wt.%Co materials, with or without addition of Cr3C2/VC grain growth inhibitors, and to sinter them by two different consolidation techniques: conventional sintering and spark plasma sintering (SPS). The dry sliding wear tests were performed on a tribometer with a ball-on-disc configuration using a WC-Co ball as a counterpart material with a normal contact load of 60 N, a sliding distance of 10000 m and a sliding speed of 0.1 m/s. The influence of the grain growth inhibitors and the consolidation techniques in sintered samples were related to the friction coefficient, wear rates and wear pattern damage. Samples sintered by non-conventional technique (SPS) show the best wear resistance and lower friction coefficient. The addition of inhibitors reduces the wear rates in materials consolidated by both techniques. The differences in the wear damage are related to microstructural parameters, mechanical properties and wear ratesThe work is supported financially by the Spanish Ministry of Science and Innovation by the project MAT2009-14144-C03-C02. L. Espinosa-Fernández, acknowledges the AECI program for the realization of the Ph.D in the ITM-UPV. A. Borrell, acknowledges the Spanish Ministry of Science and Innovation for her Juan de la Cierva contract (JCI-2011-10498)Espinosa-Fernández, L.; Borrell Tomás, MA.; Salvador Moya, MD.; Gutierrez-González, C. (2013). Sliding wear behavior of WC-Co-Cr3C2-VC composites fabricated by conventional and non-conventional techniques. Wear. 307:60-67. https://doi.org/10.1016/j.wear.2013.08.00S606730

    Soil chemical properties in abandoned Mediterranean cropland after succession and oak reforestation.

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    Large extents of cropland have been abandoned in recent decades and more may be abandoned in the near future. These may undergo secondary succession or reforestation. We experimentally tested the response of soil chemical properties to secondary succession (old field) and to Quercus ilex plantation (reforested cropland) in a Mediterranean cropland that was abandoned 13 years ago. We also evaluated the relevance of previous reforestation management (four combinations of presence and absence of irrigation and shading) in addition to current environmental conditions (herbaceous community and cover of oak canopy) on soil chemistry in the reforested cropland. Carbon and NH4+–N concentrations and availability of mineral N were higher in the reforested cropland than in the old field. However, soil pH, total N, P, K and NO3−–N concentrations, mineralization rates, and available PO43−–P were similar in the reforested cropland as well as in the old field. Previous reforestation management practices, particularly irrigation, and current environmental conditions, mostly biomass and composition of the herbaceous community, affected soil chemistry. Irrigation increased K and P concentrations and NH4+–N availability. This study highlights the overall slow dynamics of soil chemistry in Mediterranean ecosystems, which has resulted in little variation of soil properties in reforested cropland after more than a decade. Reforestation can accelerate the recovery of some soil properties of abandoned cropland in comparison with secondary succession, but these effects will be more noticeable in longer time periods.Ministerio de Ciencia y Educación, EspañaComunidad de MadridMinisterio de Economía y Competitividad, Españ

    Urban Traffic Flow Mapping of an Andean Capital: Quito, Ecuador

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    [EN] Several efforts have been devoted to developing sustainable cities to address global environmental challenges and the growth of urban areas. In particular, transportation has various issues such as air pollution, noise, and traffic, which have to be addressed by collecting significant information of the traffic and road conditions of the cities. Automating the data extraction process and street network construction will allow building more useful models to study traffic behavior. This work presents a network modeling approach to identify interest points (extreme and internal) of the city, through a winner-takes-all edge trimming, and mapping the traffic flow between them. Such points can be considered as entries of an Origin-Destination matrix, where such information can be used to model traffic behavior between interest points. The case study of Quito, Ecuador is considered. Besides, to address environmental issues, this paper encourages the replacement of internal combustion taxis with electric vehicles. From the understanding of the vehicle traffic behavior, a pre-feasibility siting of electric taxi (ET) charging stations was carried out. The results will allow performing the sizing of each charging station considering electric power network constraints. This work aims to ensure a sustainable transportation system based on this crucial information.This work was supported in part by the Universidad de Las Americas, Quito, Ecuador, under Project SIS.JCG.19.03 and Project SIS.MGR.20.01, and in part by the CYTED Network Ibero-American Thematic Network on ICT Applications for Smart Cities under Grant 518RT0559.González-Rodríguez, MS.; Clairand, J.; Soto-Espinosa, K.; Jaramillo-Fuelantala, J.; Escrivá-Escrivá, G. (2020). Urban Traffic Flow Mapping of an Andean Capital: Quito, Ecuador. IEEE Access. 8:195459-195471. https://doi.org/10.1109/ACCESS.2020.3033518S195459195471

    Towards automatic hole detection of a net for fish farms by means of robotic intelligence

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    In the last decades fish farms became one of the most important sources of seafood. This industry is facing complex and costly problems like net holes, especially due to unexpected situations, such as depredators and storm effects. This is a complex problem because fishes can escape from the fish farms containers or a depredator can enter in the container. To solve this problem divers are needed, but this solution is difficult and sometimes can be dangerous for the diver. The main objective of this work is to present the current state of a system where an underwater robot can detect holes in the net of a fish farm. Once the robot detects the hole it will proceed to manipulate it. This task is bordered using convolutional neural networks and the BlueROV2 platform with the Newton Gripper from BlueRobotics, which will be upgraded in a second stage to perform preliminary net repairs. This work contributes in the area of aquaculture, computer vision, underwater inspection and manipulation.Peer Reviewe

    Maternal copper status and neuropsychological development in infants and preschool children

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    Introduction Copper (Cu) is an essential element involved in biological processes; however, excessive Cu could be harmful because of its reactive nature. Very few studies have evaluated its potential neurotoxic effects. We aimed to evaluate the association between maternal Cu levels and children's neuropsychological development. Methods Study subjects were mother-child pairs from the Spanish INMA (i.e. Childhood and Environment) Project. Cu was measured by inductively coupled plasma mass spectrometry in serum samples taken at the first trimester of pregnancy (2003-2005). Neuropsychological development was assessed using the Bayley Scales of Infant Development (BSID) at 12 months (n = 651) and the McCarthy Scales of Children's Abilities (MSCA) at 5 years of age (n = 490). Covariates were obtained by questionnaires during pregnancy and childhood. Multivariate linear and non-linear models were built in order to study the association between maternal Cu and child neuropsychological development. Results The mean ± standard deviation of maternal Cu concentrations was 1606 ± 272 μg/L. In the multivariate analysis, a negative linear association was found between maternal Cu concentrations and both the BSID mental scale (beta = −0.051; 95% confidence intervals [CI]: −0.102, −0.001) and the MSCA verbal scale (beta = −0.044; 95%CI:-0.094, 0.006). Boys obtained poorer scores than girls, with increasing Cu at 12 months (interaction p-value = 0.040 for the mental scale and 0.074 for the psychomotor scale). This effect modification disappeared at 5 years of age. The association between Cu and the MSCA scores (verbal, perceptive performance, global memory and motor, general cognitive, and executive function scales) was negative for those children with lowest maternal iron concentrations (<938μg/L). Conclusion The Cu concentrations observed in our study were within the reference range established for healthy pregnant women in previous studies. The results of this study contribute to the body of scientific knowledge with important information on the possible neurotoxic capability of Cu during pregnancy

    Photodegradation Diuron herbicide with TiO2-Al2O3 catalysts supported on graphene nanoplatelets

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    Objective: To photodegrade Diuron with TiO2-Al2O3 nanomaterials supported on graphene nanoplatelets (GnPs) Design/methodology/approach: The synthesis of the materials was carried out by the sol-gel method under mild conditions. Subsequently, the obtained materials were subjected to thermal processing for structural stabilization and pulverized. Synthesized nanomaterials were then characterized by nitrogen adsorption/desorption, X-ray diffraction, scanning electron microscopy, and Uv-Vis spectroscopy. Results: The adsorption/desorption results indicated that the ternary TiO2-Al2O3/GnPs nanomaterials were found to have complex porosity, which suggested that TiO2-Al2O3 was formed on agglomerated GnPs. X-ray diffraction data revealed that the anatase phase of TiO2 and the g-Al2O3 phase coexist with the crystalline phase of graphene. The morphology of the materials indicates that the nanoplatelets were randomly dispersed in a continuous mixed oxide phase. About the UV analysis, the presence of GnPs at 1 wt % concentration reduces the band gap by 6%. Limitations on study/implications: The physical and chemical properties of GnPs make the material an excellent candidate for the degradation of pollutants by photocatalysis. Findings/conclusions: The addition of GnPs improved the Diuron degradation, probably by forming a nanostructured interface or heterojunction. &nbsp;Objective: To photodegrade Diuron with TiO2-Al2O3 nanomaterials supported on graphene nanoplatelets (GnPs) Design/methodology/approach: The synthesis of the materials was carried out by the sol-gel method under mild conditions. Subsequently, the obtained materials were subjected to thermal processing for structural stabilization and pulverized. Synthesized nanomaterials were then characterized by nitrogen adsorption/desorption, X-ray diffraction, scanning electron microscopy, and Uv-Vis spectroscopy. Results: The adsorption/desorption results indicated that the ternary TiO2-Al2O3/GnPs nanomaterials were found to have complex porosity, which suggested that TiO2-Al2O3 was formed on agglomerated GnPs. X-ray diffraction data revealed that the anatase phase of TiO2 and the g-Al2O3 phase coexist with the crystalline phase of graphene. The morphology of the materials indicates that the nanoplatelets were randomly dispersed in a continuous mixed oxide phase. About the UV analysis, the presence of GnPs at 1 wt % concentration reduces the band gap by 6%. Limitations on study/implications: The physical and chemical properties of GnPs make the material an excellent candidate for the degradation of pollutants by photocatalysis. Findings/conclusions: The addition of GnPs improved the Diuron degradation, probably by forming a nanostructured interface or heterojunctio

    Maternal selenium status and neuropsychological development in Spanish preschool children

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    BACKGROUND: The relationship between maternal selenium (Se) status and child neurodevelopment has been scarcely assessed. In a previous study we observed an inverse U-shaped association between maternal Se concentrations and infant neurodevelopment at 12 months of age. In this study, this non-linear association was explored at preschool age. The effect modification by breastfeeding, child's sex and cord blood mercury was also evaluated.METHODS: Study subjects were 490 mother-child pairs from the Spanish Childhood and Environment Project (INMA, 2003-2012). Child neuropsychological development was assessed at around 5 years of age by the McCarthy Scales of Children's Abilities (MSCA). Sociodemographic and dietary characteristics were collected by questionnaire at the first and third trimester of gestation and at 5 years of age. Se was measured in serum samples by ICP-MS at the end of the first trimester of pregnancy (mean ± standard deviation (SD) = 12.4 ± 0.6 weeks of gestation).RESULTS: The mean ± SD of maternal serum Se concentrations was 79.9 ± 8.1 µg/L. In multivariate analysis, no linear association was found between Se concentrations and the nine MSCA scales. Generalized additive models indicated inverted U-shaped relationships between Se concentrations and the verbal and global memory scales. When assessing the influence of effect modifiers, breastfeeding played a role: the association between Se and neuropsychological development was inverted U-shaped for the quantitative, general cognitive, working memory, fine motor, global motor and executive function scales only for non-breastfed children.CONCLUSION: Low and high maternal Se concentrations seem to be harmful for child neuropsychological development, however further studies should explore this non-linear relationship

    Pilot study of cutaneous tolerability of fibrin-agarose substitutes in healthy volunteers

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    Objetivos: En el presente estudio se persigue comprobar posibles reacciones adversas, derivadas del uso tópico de láminas de fibrina-agarosa en el antebrazo de voluntarios sanos. Metodología: Se llevó a cabo un estudio experimental en siete voluntarios sanos, cinco varones y dos mujeres, que no presentaban ningún tipo de lesión cutánea visible. En el antebrazo de cada voluntario se colocaron dos láminas de fibrina-agarosa de 4 cm2 . Cada lámina se cubrió con un apósito impregnado y sobre una de las láminas se aplicó pomada antibiótica con mupirocina. Ambas láminas se cubrieron finalmente con un apósito protector y se mantuvieron en contacto directo sobre la piel durante 48 horas. Resultados: Los resultados determinaron que no se detectaron reacciones adversas después de 48 horas de evolución ni en los siguientes 7 días en ningún voluntario. Se observaron diferencias entre las dos láminas implantadas en cada voluntario, ya que al retirar el apósito cubierto con pomada antibiótica, la lámina presentaba un aspecto más hidratado que la que no llevaba pomada antibiótica. Conclusiones: El uso tópico de las láminas de fibrina-agarosa en voluntarios sanos no presenta reacciones adversas del tipo irritación o alergia al aplicarse directamente por vía tópica. Aunque el tamaño muestral del estudio es limitado, sugiere que la combinación de fibrina-agarosa se presenta como el biomaterial idóneo para el desarrollo de un modelo de piel artificial humana.Purpose: This study aims to analyse possible adverse reactions resulting from the topical use of fibrin-agarose substitutes in the forearm of healthy volunteers. Methods: An experimental study was carried out in seven healthy volunteers, five males and two females, who did not have any cutaneous lesion. Two fibrin-agarose substitutes of 4 cm2 were placed in the forearm of each volunteer. Each substitute was covered with an impregnated dressing and one of the substitutes was covered with antibiotic ointment (mupirocin). Both substitutes were finally covered with a protective dressing. The substitutes were maintained for 48 hours. Results: The results determined that no adverse reactions were detected in any volunteer after 48 hours and a week of evolution. Differences were observed between the two substitutes implanted in each volunteer, since when removing the covered dressing with antibiotic ointment, the substitute presented a more hydrated appearance than the one without antibiotic cream. Conclusions: The implant of fibrin-agarose substitutes in healthy volunteers does not present irritation or allergic type adverse reactions when they applied directly topically on the skin. Although the sample size is low, the fibrin-agarose combination is presented as the biomaterial suitable for the development of an artificial human skin model

    COVID-19 Clinical Profile in Latin American Migrants Living in Spain: Does the Geographical Origin Matter?

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    COVID-19; Latin America; SeverityCOVID-19; Amèrica Llatina; GravetatCOVID-19; América Latina; GravedadThe aim of this study was to describe and compare the clinical characteristics of hospitalized patients with COVID-19 pneumonia according to their geographical origin. This is a retrospective case-control study of hospitalized patients with confirmed COVID-19 pneumonia treated at Vall d’Hebron University Hospital (Barcelona) during the first wave of the pandemic. Cases were defined as patients born in Latin America and controls were randomly selected among Spanish patients matched by age and gender. Demographic and clinical variables were collected, including comorbidities, symptoms, vital signs and analytical parameters, intensive care unit admission and outcome at 28 days after admission. Overall, 1080 hospitalized patients were registered: 774 (71.6%) from Spain, 142 (13.1%) from Latin America and the rest from other countries. Patients from Latin America were considered as cases and 558 Spanish patients were randomly selected as controls. Latin American patients had a higher proportion of anosmia, rhinorrhea and odynophagia, as well as higher mean levels of platelets and lower mean levels of ferritin than Spanish patients. No differences were found in oxygen requirement and mortality at 28 days after admission, but there was a higher proportion of ICU admissions (28.2% vs. 20.2%, p = 0.0310). An increased proportion of ICU admissions were found in patients from Latin America compared with native Spanish patients when adjusted by age and gender, with no significant differences in in-hospital mortality.Isabel Campos-Varela’s research activity is funded by grant PI19/00330 from Instituto de Salud Carlos III. CIBERehd is supported by Instituto de Salud Carlos III. The work was independent of all funding. This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors
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