782 research outputs found

    An integrated model of structural equations with cognitive and environmental factors for the study of active commuting

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    This work was partially supported with funds from the FEDER Projects /Ministry for Science and Innovation, ECO2017-89452-R, and PGC2018-095786-B-I00, Spain.Introduction: The active commuting can be defined as the action of displacement to the educa-tional or work centre by way of any non-motorised means of transport, usually by walking or cycling. The aim of this study is to identify and evaluate cognitive and environmental factors for the active commuting. Methods: In order to propose a set of beliefs and attitudes that explain the main possible moti-vations for an individual to carry out the active commuting, a model based on the Theory of Planned Behaviour, health and environment is developed. To compute the results, a structural equations model is proposed instead of another standard regression technique, due to the use of multiple indicators for each latent construct. The proposed model permits to evaluate each of the aspects and to quantify their contribution to the global behavioural intention. Results: The computation of the structural equations model concludes that, for the intention to practise active commuting, the most influential variable is attitude, followed by health and environmental awareness. It is interesting to see that perceived behavioural control exerts a negative influence on the intention, while the subjective norm has no significant effect. Conclusions: From the results of this study can be induced that the perceived behavioural control, health, and environmental awareness exert a significant influence on attitude and intention to practice active commuting. Furthermore, the results also show that attitude influences as a pre-cursor to the intention of practicing and permit to rank the relative weight of each aspect: atti-tude, health and environmental awareness. Hence, political measures that publicise the benefits of active commuting in these particular aspects should have significant results in the promotion of this activity.Universidad Pablo de Olavid

    Choosing a travel agency franchise by mean of a global composite indicator: an application in Spain

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    This paper highlights the complexity of the franchise partner selection process from a franchisee's perspective. The purpose of this article is, firstly, to propose the definition of a system of indicators which include all the relevant information which the potential franchisee should take into consideration when choosing a chain secondly, to obtain a global composite indicator for the construction of a ranking of franchisors. In order to illustrate the procedure, a sample of travel agency franchisors in Spain and a suitable database to quantify the indicators are considered. The paper concludes constructing a complete order of the franchisors in the travel agency industry. In addition, the results show the most important characteristics of franchisors that potential franchisees must take into account. The value of the paper is significant as it provides a practical frame – work for potential franchisees in the selection of franchisors. First published online: 12 Sep 201

    Analyzing the Risk of Being a Victim of School Bullying. The Relevance of Students’ Self-Perceptions

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    This work was supported by grant from the Ministry of Economy, Knowledge, Business and University, of the Andalusian Government, within the framework of the FEDER Andalusia 2014–2020 operational program. Specific objective 1.2.3. «Promotion and generation of frontier knowledge and knowledge oriented to the challenges of society, development of emerging technologies») within the framework of the reference research project (UPO-1380624). FEDER co-financing percentage 80%.School bullying is a growing concern in almost all developed economies, bringing negative and serious consequences for those students involved in the role of victims. In this paper, we propose to analyze this topic for the case of Spain, considering the data compiled in the Programme for International Student Assessment (PISA) report in 2018. The sample size consists of 12,549 15-old-year students (51.84% females and 48.16% males). With the help of structural equation models (SEM), we aim to detect the relationship between the risk of being a victim of bullying and several self-appreciations expressed by the students. We have considered variables that try to measure individual perceptions in several aspects, such as the self-image, the help provided by parents and teachers and how the school environment’s safety is perceived. A multigroup analysis was also performed to see the impact of the socioeconomic level of the families and the students’ academic performances on the proposed model. We conclude that several of those aspects are directly related with the risk of being bullied and this risk is higher in those students who present school failure and have a lower socioeconomic status. In this regard, the results would permit pointing out some aspects in which the decision-makers can focus their proposals to establish prevention measures.Departamento de Economía, Métodos Cuantitativos e Historia Económica. Universidad Pablo de Olavid

    Foveal avascular zone and choroidal thickness are decreased in subjects with hard drusen and without high genetic risk of developing Alzheimer’s disease

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    A family history (FH+) of Alzheimer’s disease (AD) and ɛ4 allele of the ApoE gene are the main genetic risk factors for developing AD, whereas ɛ4 allele plays a protective role in age-related macular degeneration. Ocular vascular changes have been reported in both pathologies. We analyzed the choroidal thickness using optical coherence tomography (OCT) and the foveal avascular zone (FAZ) using OCT-angiography and compared the results with ApoE gene expression, AD FH+, and the presence or absence of hard drusen (HD) in 184 cognitively healthy subjects. Choroidal thickness was statistically significantly different in the (FH−, ɛ4−, HD+) group compared with (i) both the (FH−, ɛ4−, HD−) and the (FH+, ɛ4+, HD+) groups in the superior and inferior points at 1500 μm, and (ii) the (FH+, ɛ4−, HD+) group in the superior point at 1500 μm. There were statistically significant differences in the superficial FAZ between the (FH+, ɛ4−, HD+) group and (i) the (FH+, ɛ4−, HD−) group and (ii) the (FH+, ɛ4+, HD−) group. In conclusion, ocular vascular changes are not yet evident in participants with a genetic risk of developing AD

    University Students' Digital Competence in Three Areas of the DigCom 2.1 Model: A Comparative Study at Three European Universities.

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    This study analysed the digital competence of 1,073 students at one Italian and two Spanish universities using the COBADI 2.0 (Basic Digital Competences/Registered Trademark 2970648) questionnaire. A quantitative methodology was applied to university students' use of, and competence in, three areas of DigCom 2.1: information and data literacy, communication and collaboration, and digital content creation. The results showed that these future graduates had an upper intermediate level of competence in information and digital literacy, and communication and collaboration, but a lower intermediate level in terms of digital content creation, particularly in the creation and dissemination of multimedia content using different tools. Two student profiles were identified for time spent online: those who dedicated a lot of their time to gaming or interacting on social media, and those who used most of their online time to searching for information and completing academic work

    Characterization of retinal drusen in subjects at high genetic risk of developing sporadic Alzheimer’s disease: An exploratory analysis

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    Having a family history (FH+) of Alzheimer’s disease (AD) and being a carrier of at least one ε4 allele of the ApoE gene are two of the main risk factors for the development of AD. AD and age-related macular degeneration (AMD) share one of the main risk factors, such as age, and characteristics including the presence of deposits (Aβ plaques in AD and drusen in AMD); however, the role of apolipoprotein E isoforms in both pathologies is controversial. We analyzed and characterized retinal drusen by optical coherence tomography (OCT) in subjects, classifying them by their AD FH (FH-or FH+) and their allelic characterization of ApoE ε4 (ApoE ε4-or ApoE ε4+) and considering cardiovascular risk factors (hypercholesterolemia, hypertension, and diabetes mellitus). In addition, we analyzed the choroidal thickness by OCT and the area of the foveal avascular zone with OCTA. We did not find a relationship between a family history of AD or any of the ApoE isoforms and the presence or absence of drusen. Subjects with drusen show choroidal thinning compared to patients without drusen, and thinning could trigger changes in choroidal perfusion that may give rise to the deposits that generate drusen

    Eficacia de la alta presión hidrostática como tratamiento cuarentenario para mejorar la calidad de los frutos del mango infestados por la mosca de la fruta Mexicana Anastrepha ludens

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    High hydrostatic pressure (HPP) has been reported as an alternative quarantine process in fruits infested by Ceratitis capitata Wiedemann, Rhagoletis indifferens Curran and Cydia pomonella (L.). In Mexico and other Latin-American countries, the Mexican fruit fly Anastrepha ludens Loew is one of the most important insects infesting mangoes, citrus, and other fruits. The present study aimed to determine the effect of pressure level and time on the survival of eggs and larvae of the Mexican fruit fly. Eggs and larvae were pressurized at 25, 50, 75, 100, or 150 MPa for 0, 5, 10 or 20 min at 25 8C. Ripe and green mangoes were also pressurized under the same conditions. On pressurized eggs of 1, 2, 3, and 4 days old, their ability to hatch was recorded. On pressurized first, second and third instars, the percentage of survival was registered. Furthermore, third instars were studied for their ability to pupate and to develop adults. The results showed that although most of eggs and larvae died at pressures lower than 100 MPa, some of them were able to survive even at 150 MPa, and a few third instars were able to pupate and to develop to adulthood. Green mangoes were affected by pressures above 75 MPa but they were more resistant than ripe mangoes. HPP treatments seem to be feasible as a quarantine process for mangoes; however, more studies, such as combining HPP with temperature treatments, are needed in order to decrease the pressure level to avoid fruit damageLa alta presión hidrostática ha sido descrita como un proceso de cuarentena alternativa en frutas infestadas por Ceratitis capitata Wiedemann, Rhagoletis indifferens Curran y Cydia pomonella (L.). En México y otros países Latinoamericanos, la mosca de la fruta mexicana Anastrepha ludens Loew es uno de los más importantes insectos que infestan los mangos, cítricos y otras frutas. El presente estudio tuvo como meta determinar el efecto del nivel de presión y tiempo sobre la supervivencia de huevos y larvas de la mosca de la fruta mexicana. Huevos y larvas se presurizaron a 25, 50, 75, 100, y 150 MPa durante 0, 5, 10, y 20 min a 25 8C. Mangos maduros y verdes también se presurizaron bajo las mismas condiciones. En huevos presurizados de uno, dos, tres y cuatro días de vida, se registró su capacidad para eclosionar. En primera, segunda y tercera etapa larvaria presurizada, el porcentaje de supervivencia también se registró. Además, en la tercera etapa larvaria se estudió su capacidad para salir de la crisálida y desarrollar adultos. Los resultados mostraron que aunque la mayoría de los huevos y larvas murieron a presiones por debajo de 100 MPa, algunos de ellos fueron capaces de sobrevivir aun a 150 MPa, y unas pocas larvas de tercera etapa fueron capaces de salir de la crisálida y desarrollar adultos. Los mangos verdes se vieron afectados por las presiones por encima de 75 MPa pero fueron más resistentes que los mangos maduros. Los tratamientos de alta presión hidrostática parecen ser un proceso viable como método cuarentenario para mangos, sin embargo, se necesitan más estudios tales como la combinación de alta presión hidrostática junto con tratamientos térmicos para disminuir los niveles de presión y evitar daños en la frutaThe authors are grateful to Fondo Mixto CONACYT –Gobierno del Estado de Tamaulipas for the financial support of this work (Project TAMPS-2003-C02-15), to CONACYT for the scholarship granted to author Hugo Ernesto CandelarioS

    Model mjerenja učinkovitosti učenja i zadovoljstva studenata tijekom pandemije bolesti COVID-19

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    The aim of this research was to assess the learning efficacy and level of satisfaction of university students as they adapted to the online teaching model amid the restrictions imposed as a result of COVID-19. The sample consisted of 467 students attending a public University of Spain. The study applied a structural equations methodology with a triangulated approach. The results show that the most influential factor in student online learning satisfaction is teacher-student interaction. On the other hand, student learning efficacy mainly depends on their attitude towards the use of technology; this makes it essential to understand which elements of the online learning system facilitate and incentivize the creation of a good learning environment. Moreover, the design quality of the system and the tools that make it function, and how they link to content and competences, all directly influence perceived ease-of-use and student satisfaction with online teaching.Cilj ovoga istraživanja bio je procijeniti učinkovitost učenja i razinu zadovoljstva studenata tijekom privikavanja na online nastavu uslijed ograničenja nametnutih zbog pandemije bolesti COVID-19. Uzorak ispitanika sastojao se od 467 studenata državnoga sveučilišta u Španjolskoj. U istraživanju je primijenjena metodologija strukturnih jednadžbi i pristup triangulacije. Rezultati pokazuju da je najutjecajniji faktor zadovoljstva učenjem u online okružju interakcija između studenta i nastavnika. S druge strane, učinkovitost učenja najviše ovisi o njihovim stavovima prema korištenju tehnologije. Zbog toga je nužno razumjeti koji elementi učenja u online okružju pomažu i potiču stvaranje dobroga okružja za učenje. Štoviše, kvaliteta dizajna sustava, alati koji im omogućuju rad te kako se oni povezuju sa sadržajem i kompetencijama zajedno izravno utječu na percepciju lakoće korištenja i na zadovoljstvo studenata online nastavom

    Glaucoma: from pathogenic mechanisms to retinal glial cell response to damage

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    Glaucoma is a neurodegenerative disease of the retina characterized by the irreversible loss of retinal ganglion cells (RGCs) leading to visual loss. Degeneration of RGCs and loss of their axons, as well as damage and remodeling of the lamina cribrosa are the main events in the pathogenesis of glaucoma. Different molecular pathways are involved in RGC death, which are triggered and exacerbated as a consequence of a number of risk factors such as elevated intraocular pressure (IOP), age, ocular biomechanics, or low ocular perfusion pressure. Increased IOP is one of the most important risk factors associated with this pathology and the only one for which treatment is currently available, nevertheless, on many cases the progression of the disease continues, despite IOP control. Thus, the IOP elevation is not the only trigger of glaucomatous damage, showing the evidence that other factors can induce RGCs death in this pathology, would be involved in the advance of glaucomatous neurodegeneration. The underlying mechanisms driving the neurodegenerative process in glaucoma include ischemia/hypoxia, mitochondrial dysfunction, oxidative stress and neuroinflammation. In glaucoma, like as other neurodegenerative disorders, the immune system is involved and immunoregulation is conducted mainly by glial cells, microglia, astrocytes, and Müller cells. The increase in IOP produces the activation of glial cells in the retinal tissue. Chronic activation of glial cells in glaucoma may provoke a proinflammatory state at the retinal level inducing blood retinal barrier disruption and RGCs death. The modulation of the immune response in glaucoma as well as the activation of glial cells constitute an interesting new approach in the treatment of glaucoma

    Adaptación a los nuevos Grados de las metodologías docentes empleadas en una asignatura de Estadística Económico-Empresarial

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    Durante el presente curso 2009/2010 la Universidad Pablo de Olavide (UPO), de Sevilla, ha puesto en marcha el nuevo mapa de titulaciones adaptado al Espacio Europeo de Educación Superior (EEES), el cual está compuesto por 16 grados y 6 dobles grados. Hasta llegar a este punto la UPO trabajó duro durante más de 6 años en la adaptación de su docencia al nuevo marco establecido por dicho EEES. Con tal objetivo, se puso en marcha en la Facultad de Empresariales, entre otras, una Experiencia Piloto de implantación del sistema de créditos europeos pretendiendo, fundamentalmente, renovar la metodología docente, incrementar la calidad de la docencia y de hacerla más cercana al alumno, siempre atendiendo a los planes de estudio actualmente vigentes. En el presente trabajo mostramos la adaptación que se realizó en la asignatura de Estadística e Introducción a la Econometría de la extinta Licenciatura en Administración y Dirección de Empresas en el marco de la Experiencia Piloto y los cambios que se acometieron posteriormente para su implantación en el nuevo Grado en Administración y Dirección de Empresas bajo el nombre: Estadística Empresarial I. Haremos hincapié en aquellos aspectos más destacados relativos al nuevo sistema de evaluación basado en evaluación continua.Artículo revisado por pare
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