2,559 research outputs found
Eficacia de los programas de prevención del ciberacoso sobre los niveles de perpetración: un metanálisis
Cyberbullying is a new and growing bullying practice that generates more harmful consequences than even traditional bullying. In this situation, the role of education plays a decisive role in the fight against this type of practice. In fact,in recent years there has been a significant increase in the number of educational interventions on cyberbullying. However, the scientific literature shows hardly any conclusive results on the effectiveness of these interventions. Therefore, the aim of this meta-analysis is to analyse the effects that prevention programmes on cyberbullying have on the levels of perpetration among school students. To this end, a search strategy was carried out according to the PICOS framework and PRISMA criteria in five different databases: Web of Science (WoS), SCOPUS, Educational Research Information Centre (ERIC), PubMed, ScienceDirect, SpringerLink and Google Scholar. After searching and applying inclusion/exclusion filters, 9 studies were included in the meta-analysis, covering a total of 17 different interventions conducted between 2015 and 2019. These studies described the application of different intervention programmes to students aged between 10 and 17 years. The findings of this meta-analysis showed that educational prevention programmes could decrease levels of bullying perpetration (SMD = 0.08; 95% CI [0.05, 0.11]; p < 0.00001). Implications for strengthening and expanding cyberbullying prevention programmes in the educational context are discussed. In addition, future research is invited to go beyond the educational setting and consider other variables and factors that extend outside the educational environment and that are equally relevant, as well as to focus new lines of research on the important role of the cyberassistant student as an essential part of this type of situationEl ciberacoso es una nueva y creciente práctica que genera consecuencias más dañinas que incluso el acoso tradicional. En esta situación, el papel de la educación juega un papel decisivo en la lucha contra este tipo de situaciones. De hecho, en los últimos años se ha producido un aumento significativo del número de intervenciones educativas sobre el ciberacoso. Sin embargo, la literatura científica apenas muestra resultados concluyentes sobrela eficacia de estas intervenciones. Por lo tanto, el objetivo de este meta-análisis es analizar los efectos que los programas de prevención del ciberacoso tienen sobre los niveles de perpetración entre los estudiantes escolares. Para ello, se realizó unaestrategia de búsqueda según el marco PICOS y los criterios PRISMA en cinco bases de datos diferentes: Web of Science (WoS), SCOPUS, Educational Research Information Centre (ERIC), PubMed, ScienceDirect, SpringerLink y Google Scholar. Tras la búsqueda y la aplicación de los filtros de inclusión/exclusión, se incluyeron 9 estudios en el metaanálisis, que abarcaban un total de 17 intervenciones diferentes realizadas entre 2015 y 2019. Estos estudios describían la aplicación de diferentes programas de intervención a estudiantes de entre 10 y 17 años. Los hallazgos de este meta-análisis mostraron que los programas de prevención educativa podrían disminuir los niveles de perpetración de bullying (DME = 0,08; IC del 95% [0,05, 0,11]; p < 0,00001). Se discuten lasimplicaciones para reforzar y ampliar los programas de prevención del ciberacoso en el contexto educativo.Además, se invita a futuras investigaciones a ir más allá del ámbito educativo y considerar otras variables y factores que se extienden fuera del entorno educativo y que son igualmente relecantes, así como enfocar nuevas líneas de investigación al importante papel del alumnado ciberayudante como parte esencial en este tipo de situaciones
Abnormally Low Tenders in Non-pricing Criteria: the Need for Control
[EN] As public procurement accounts for approximately 10 to 15% of gross domestic product (GDP) in developed countries, tendering mechanisms should be clearly defined in order to avoid any actions that could endanger the basic principle that all bidders should be on equal terms. An Abnormally Low Tender (ALT) is defined as an offer too low to provide a normal level of profit and that cannot be explained on the basis of construction methods, the technical solution chosen, the originality of the work, or the favorable conditions of the tenderer. Public bodies are well aware of the risk of accepting an offer that cannot be carried out and despite the difficulty of detection recommendations for their prevention usually focus on the price criterion. Most tenders are awarded to the economically most advantageous tender (EMAT), which is assessed by various criteria (including price), though other criteria often have equal or greater weight in the final decision. The method used in this research study is divided into two main phases. First, the score of the bidders is obtained for criteria evaluated by formulae other than price, based on the contract terms of three case studies, after which new scores for these award criteria are obtained from ALT formulae, then, the results of both scoring methods are analyzed. This paper defends the need to control abnormally low tenders by means of award criteria evaluated by formulae other than those of price.Fuentes Bargues, JL.; González-Cruz, M.; González-Gaya, C. (2016). Abnormally Low Tenders in Non-pricing Criteria: the Need for Control. Universal Journal of Management. 4(12):659-669. doi:10.13189/ujm.2016.041202S65966941
Sistema de gestión energético óptimo para edificios inteligentes con sistemas de generación renovable integrados
Como solución para los nuevos edificios que desean adquirir la etiqueta de “edificios inteligentes” proponemos un software de gestión energética optima. Se trata de un sistema centralizado capaz de gestionar elementos de generación (por ejemplo, unidades de generación renovables integradas en el edificio), un sistema de almacenamiento y los distintos tipos de demanda que puede generar dicho edificio. Con el objetivo de un control energético total, el sistema consta de tres niveles distintos de gestión y a su vez, con tres modos de funcionamiento diferentes. Para demostrar el funcionamiento de esta herramienta se incluyen los resultados sobre un escenario emulado que consta de una pequeña generación solar, de tres niveles distintos de demanda propia y la demanda de un vehículo eléctrico que a su vez podrá servir de almacenaje energético mientras este permanezca aparcado.Peer ReviewedPostprint (author’s final draft
Métodos numéricos para problemas de mínimos cuadrados y ajuste de parámetros en modelos matemáticos de memristores
En este trabajo se estudian distintos métodos numéricos para resolver los problemas de mínimos cuadrados, haciendo especial hincapié en los casos nolineales. Además, implementando uno de los métodos por medio de Matlab, se analiza un modelo matemático existente en el campo de la electrónica que trata de describir el comportamiento de los memristores, logrando ajustar los parámetros desconocidos que aparecen en dicho modelo a unas curvas experimentales previamente obtenidas en el laboratorio.Grado en Matemática
Modelización matemática de curvas experimentales en regímenes estacionarios y dinámicos de memristores
En este trabajo se estudian unos nuevos dispositivos, denominados memristores, que poseen un gran interés en la actualidad por sus innovadoras aplicaciones en el campo de la electrónica. Empezando por el descubrimiento de estos dispositivos, en este TFG se hace una descripción de sus propiedades fundamentales y una clasificación general para posteriormente hacer un análisis detallado de los modelos matemáticos utilizados para describir el funcionamiento de estos dispositivos, destacando el modelo de memdiodo desarrollado por el investigador Enrique Miranda, siendo uno de los más reconocidos por la comunidad científica. También se incluye en el trabajo una propuesta de mejora de dicho modelo, basada en los resultados encontrados al realizar una serie de simulaciones usando el programa de Matlab y unos datos experimentales recopilados tras la realización de dos experimentos en los laboratorios del Departamento de Electricidad y Electrónica de la UVA.Grado en Físic
Possible preventive effect of inositol in folate- resistant spina bifida occulta mouse model
Motivation: Neural tube is the embryonic structure that develops into the brain and spinal cord. Failure in the process of neural tube closure during embryonic development results in severe birth defects called neural tube defects (NTDs), including anencephaly and spina bifida. Susceptibility to NTDs is influenced by genetic and environmental factors including maternal nutrition. Clinical trials demonstrate that up to 70% of NTDs can be prevented by folic acid supplementation in early pregnancy whereas the remaining NTDs are resistant to folate. Spina bifida occulta (SBO) is included in these folic acid non-responsive NTDs. Previous studies demonstrate that inositol, a water-soluble vitamin, prevents NTDs in genetic mice models of folate-resistant NTDs, such as curly tail mutants mice. Moreover, D-chiro-inositol isomer is more effective than myo-inositol reducing the frecuency of spina bifida in curly tail mice. Loop-tail mutants mice are also resistant to supplementation with folic acid. These Loop-tail (Lp) mice are mutants for Vangl2 gene implicated in the non-canonical Wnt signalling pathway (Wnt-PCP), which have a crucial role in the beginning of the closure of the neural tube. At embryonic day 11.5 (E11.5) is evident the failure of dorsal fusion of neural folds in Lp+/- embryos and a cellular aggregate appears covering this defect. This aggregate resembles the lipoma characteristic of lipomyelomeningocele, the most common form of SBO. In this project, we are going to study the possible effect of D-chiro-inositol maternal supplementation to reduce the incidence of dorsal fusion failure and the formation of the cellular aggregate in Lp+/- embryos and in Lp+/-: Daam1+/gt double mutant embryos (both genes are members of the Wnt-PCP pathway), in which the cellular aggregate also develops.Methods: Oral administration of D-chiro-inositol to pregnant mice was performed twice daily intervals from E8.5 to E10.5. These females were paired either with Lp+/- or with Lp+/-: Daam1+/gt double mutants male mice and they were sacrified at E12.5. Embryos were genotyped and the results were compared to the macroscopic phenotype that was previosly registered. Histological studies allowed us to verify the existence of the cellular aggregate in Lp+/- and Lp+/-: Daam1+/gt embryos. In addition, hybridization in situ and immunohistochemistry were carried out to analyze the expression of certain genes to characterize the cellular aggregate
Obesity prevention messages, risk behaviors for eating disorders and body mass index: Cluster analysis
Public health experts have argued that obesity prevention campaigns can have negative health effects such as risk behaviors for eating disorders. This study aimed to identify the relationship between body mass index, the presence of risk behaviors for eating disorders, and hearing to obesity prevention messages. The adolescents were measured to calculate their body mass index. The presence of risk behaviors for eating disorders was evaluated, and the number and frequently of obesity prevention messages they heard was registered. A cluster analysis was used for the statistical analysis. Among the results it was found, that the adolescents reported hearing an average of seven different obesity prevention messages in one week; the most commonly heard message was measure your waist. The most common risk behaviors for eating disorders seen in the adolescents were excessive exercise and fear of gaining weight. One cluster were identified obese adolescents that reported hearing fewer obesity prevention messages and presented various risk behaviors for eating disorders. Other cluster were normal weight adolescents that reported hearing more obesity prevention messages and presented few risk behaviors for eating disorders. In conclusion, it is advisable to design campaigns that simultaneously prevent obesity and risk behaviors for eating disorders.Fil: Cruz Licea, Verónica. Universidad Nacional Autónoma de México; MéxicoFil: Morán Álvarez, Isabel Cristina. Universidad Nacional Autónoma de México; MéxicoFil: Plascencia González, Carmen. Universidad Nacional Autónoma de México; MéxicoFil: Gongora, Vanesa Carina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Palermo. Facultad de Ciencias Sociales. Departamento de Psicología; Argentin
A methodology to select the price criterion in public procurement
The construction sector is a key driver for economic growth in any nation and public procurement is one of its pillars - hence the importance of the study and investigation of its mechanisms, especially tendering criteria. Price is the main deciding factor for most tenders and projects must have an appropriate base price relative to market price to avoid problems during the execution of the project. Most research on price criteria has been developed from the point of view of bidders and has discussed the development of tools and methodologies for determining the optimal bid price. In this paper we propose a methodology for public procurement procedures from the point of view of the administration. The methodology enables setting all aspects of the price criterion based on the size of the project budget, the nature of the work, and the number of bidders
A methodology to detect the deviations of the project´s budget compared to market prices
The budget of a project reflects the cost of the investment needed to build an infrastructure, install a system or acquire new materials or supplies. A well-formulated budget in accordance with market prices, allows contractors to prepare offers according to their technical, economic and financial characteristics. On the other hand, it avoids current philosophies that aim to get the contract at any price. Philosophies subsequently used to point out problems and claims during the execution of the project (contradictory prices, delays, etc.) in order to recover some or the entire economic bid carried out during the tendering. In this paper a simple and fast methodology is developed to check if the tendering price is in accordance with market prices, so that the economic viability of the project is not at risk. The application of the methodology on a sample of projects allows us to check the influence of the type of project (civil or building) on the characteristics of the budget. It also allows us to point out the insufficient economic endowment of the projects as the start of the subsequent problems during the execution of the work
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