Modeling of the Bitcoin volatility through key financial environment variables: an application of conditional correlation MGARCH models

Since the launch of Bitcoin, there has been a lot of controversy surrounding what asset class it is. Several authors recognize the potential of cryptocurrencies but also certain deviations with respect to the functions of a conventional currency. Instead, Bitcoin’s diversifying factor and its high return potential have generated the attention of portfolio managers. In this context, understanding how its volatility is explained is a critical element of investor decision-making. By modeling the volatility of classic assets, nonlinear models such as Generalized Autoregressive Conditional Heteroskedasticity (GARCH) offer suitable results. Therefore, taking GARCH(1,1) as a reference point, the main aim of this study is to model and assess the relationship between the Bitcoin volatility and key financial environment variables through a Conditional Correlation (CC) Multivariate GARCH (MGARCH) approach. For this, several commodities, exchange rates, stock market indices, and company stocks linked to cryptocurrencies have been tested. The results obtained show certain heterogeneity in the fit of the different variables, highlighting the uncorrelation with respect to traditional safe haven assets such as gold and oil. Focusing on the CC-MGARCH model, a better behavior of the dynamic conditional correlation is found compared to the constant

La documentación audiovisual en las empresas audiovisuales locales e instituciones universitarias andaluzas

Estado actual del proyecto, desarrollado por el Grupo de Investigación en Comunicación Científica y Desarrollo del Departamento de Periodismo de la Universidad de Sevilla, sobre la situación real de la práctica documental en las empresas audiovisuales de la Comunidad Autónoma Andaluza.State of the proyect, developed by the Research Group in Scientific Communication and Development of the Departament of Journalism of the University of Sevilla, on the current real situation of the documentary practice in the audiovisual organizations of Andalucía

Physical Education and the development of autonomy: the perception of the students of Secondary Education

Este estudio se centró en conocer la percepción del alumnado sobre el apoyo docente al desarrollo de su autonomía en Educación Física (EF). Se aplicó la Escala de Percepción de Apoyo a la Autonomía en las Clases de Educación Física (EPAACEF), diseñada por los autores de este artículo y validada con adecuadas propiedades psicométricas. La escala, conteniendo 34 ítems, agrupados en cuatro dimensiones, fue aplicada a 721 alumnos y alumnas de Educación Secundaria (347 chicas), con una media de edad de 14.4 (±1.5) años. Este alumnado recibe clases de EF de siete docentes, con formación específica en EF y diferente experiencia en la enseñanza. Los resultados muestran la idoneidad de diseñar la EPAACEF, porque permite valorar los comportamientos docentes desde una perspectiva más sistémica, pudiendo afirmar que, según la percepción del alumnado, los comportamientos que apoyarían un desarrollo de su autonomía se producen con una frecuencia «moderadamente baja». Los docentes obtienen mejores resultados en los comportamientos relacionados con la atención a la motivación, y con la atención al desarrollo cognitivo y metacognitivo, debiendo atender más a las necesidades del alumnado relacionadas con los ritmos de aprendizaje y con fomento de sugerencias y participación activa. Analizando la EPAACEF globalmente no se producen diferencias significativas en función del género y de la edad, pero sí en alguna de las dimensionesThis study focused on the perception of students on the teaching support to the development of their autonomy in Physical Education (PE). The Autonomy Support Perception Scale in the Physical Education Classes (EPAACEF), designed by the authors of this article and validated with adequate psychometric properties, was applied. The scale, containing 34 items, grouped in four dimensions, was applied to 721 students of secondary education (347 girls), with a mean age of 14.4 (± 1.5) years. These students receive PE classes of seven teachers, with specific training in PE and different teaching experience. The results show the appropriateness and validity of the EPAACEF, because it allows evaluating teacher behaviours from a more systemic perspective, being able to affirm that, according to the perception of the students, the behaviours that would support a development of their autonomy occur with a frequency «moderately low». Teachers obtain better results in the behaviours related to attention to motivation, and attention to cognitive and metacognitive development. They must attend more to the needs of students related to learning rhythms and encouraging suggestions and active participation. Analysing the EPAACEF globally, there are no significant differences in terms of gender and age, but exist in some of the dimension

Antitumoral properties of Sorafenib, Regorafenib, Cabozantinib and Lenvatinib in 3D tumor liver cell culture

Motivation: Most researchs to find effective therapies to treat cancer has been done in cell lines grown in monolayer that don´t take into account the three-dimensional structure of the tumor or the interactions between the tumor cells. In cell cultures in two dimensions, all cells are exposed in the same way to the therapeutic agent, so the results are not very precise.For this reason, it is important to develop cell culture techniques in which it is possible simulate in vivo conditions to predict more exactly the behavior and cellular interactions within the tumor. Like tumors, spheroids are three-dimensional aggregates of cancer cells that naturally form regions of hypoxia.Methods: To carry out this study we have used three different cell lines: HepG2, Hep3B and Huh7. First, the cells were cultured in 96-well plates coated with agarose. The spheroids were collected on day 5, 8 (when treated with the different drugs), 10, 12 and 15. The collected spheroids were fixed with paraformaldehyde, passed through a paraffination cycle, were introduced in paraffin blocks and cut with the microtome. Other spheroids were disintegrated by trypsinization to determine the number of cells and lysates to be able to determine caspase-3 activity. The parameters that we have measured have been apoptosis, cell proliferation, cell viability, cell death, hypoxia and cell growth. In addition, was carried out a study of the expression of  different growth factor receptors such as EGFR, VGFR, FGFR ans PDGFR by immunodetection.Results: Sorafenib and Regorafenib induced cell death and reduced cell proliferation both in 2D and 3D cultured HCC lines. These effects are higher than those observed with Cabozantinib and Lenvatinib in the same conditions. The expression of some receptors such as EGFR is reduced in the cells treated for 24 hours with sorafenib and regorafenib but no changes are observed in the cells treated with lenvatinib and cabozantinib with respect to the control.Conclusions: The observed resistance of Lenvatinib and Cabozantinib treatment to the induction of cell death and cell cycle arrest in comparison with that observed with Sorafenib and Regorafenib may be related to the induction of EGFR-dependent pathway

Producción científica de la revista Investigación y Educación en Enfermería en sus 30 años de edición

ABSTRACT: This study sought to characterize the scientificproduction of the journal Investigación y Educación enEnfermería (IEE) during its 30 years of editing. Methodology.Documentary type longitudinal study, which analyzed all thearticles published in IEE from 1983 to 2012; a total of 656.Each article was manually revised and an instrument was usedcontaining the variables of author and article characteristics.Results. A total of 47% of the articles have a sole author and only one institution of affiliation. According to their type, those with the most contributions were original articles (42%) and theme reviews (25%). Regarding the characteristics of the first authors, nurses predominate (74%); with graduate formation (71%); with academic affiliation (88%); and country of origin being Colombia (70%). The principal themes dealt with are: nursing care (24%), nursing education and formation (14%), nursing practice (6%), and nursing history (5%). The most frequent populations objects of study are nurses (25%) and nursing students (8%). A total of 15% deal with vulnerable populations (elderly, children, pregnant women, the handicapped, and individuals from rural areas, among others). Additionally, the following tendencies were noted:authors have improved in their levels of formation, and regarding the increased number of original articles and balance per type of research paradigm. Conclusion. Author’s characteristics and thematic preferences, along with populations object of the articles show that progress has been produced in divulging knowledge generated and of the experiences in their implementation in nursing practice, thus, contributing to the discipline’s development.RESUMEN: Caracterizar la producción científica de la revista Investigación y Educación en Enfermería (IEE) en sus 30 años de edición. Metodología. Estudio longitudinal de tipo documental en el que se analizaron todos los artículos publicados en IEE de 1983-2012; en total 656. Se revisó manualmente cada artículo y se utilizó un instrumento que contenía las variables de las características de los autores y de los artículos. Resultados. El 47% de ellos tiene un solo autor y una sola institución de afiliación. Según su tipo, los que más aportan al total son los originales (42%) y las revisiones de tema (25%). Características de los primeros autores: predominan los enfermeros (74%), con formación de posgrado (71%), con afiliación académica (88%) y el país de origen es Colombia (70%). Los principales temas tratados son el cuidado de enfermería (24%), la educación y formación en enfermería (14%), su práctica (6%) y su historia (5%). Las poblaciones objeto de estudio más frecuentes son los enfermeros (25%) y los de estudiantes de enfermería (8%). Un 15% versan sobre poblaciones vulnerables (adultos mayores, niños, las gestantes, discapacitados y las personas de áreas rurales, entre otros). Por otra parte, se observaron las siguientes tendencias: los autores han mejorado en su nivel de formación, en cuanto al aumento en el número de artículos originales y equilibrio por tipo de paradigma de investigación. Conclusión. Las características de los autores y las preferencias temáticas y las poblaciones objeto de los artículos muestran que se han producido avances en divulgación del conocimiento generado y de las experiencias en su implementación en la práctica de la enfermería, contribuyendo de esta forma al desarrollo de la disciplina

Estilos de vida de estudantes de Enfermagem de uma universidade pública colombiana

Objective. To assess the lifestyles of nursing students from a Colombian public university. Methods. A cross-sectional study was conducted in 2014. 380 students answered by self-reporting the adapted version in Spanish of FANTASTIC Lifestyles Assessment Questionnaire of Wilson and Ciliska. Results. Lifestyles were poor in 9.2%, fair in 31.3%, good in 53.7%, and excellent in only 5.8% of the participants. Statistically-significant differences of the total mean score were not found when comparing with gender, age group, and course year, but were detected in two domains by gender: a) physical activity (higher score in men) and b) cigarette smoking (higher score in women). Conclusion. An important proportion of our nursing students has inadequate lifestyles, which means deferred risks for the development of chronic diseases. Universities should promote the training of the future professionals in nursing with knowledge and skills aimed at healthy lifestyles.Objetivo. Evaluar los estilos de vida de los estudiantes de Enfermería de una universidad pública colombiana. Métodos. Se realizó un estudio descriptivo de tipo trasversal en 2014. 380 alumnos por autorreporte contestaron el FANTASTIC Lifestyle Assessment Questionnaire, versión adaptada al español. Resultados. La puntuación de los estilos de vida fue bajo en el 9.2%; en el 31.3%, regular; en el 53.7%, bueno y solo en el 5.8%, fantástico. No se detectaron diferencias estadísticamente significativas del promedio de la puntuación total cuando se comparó con sexo, grupo etario y año de curso, pero en sí en dos dominios del cuestionario: actividad física (puntuación mayor en hombres que mujeres) y b) consumo de tabaco (promedio de puntuación mayor mujeres que en hombres). Conclusión. Una proporción importante de alumnos de Enfermería de la universidad pública estudiada tiene inadecuados estilos de vida, lo que significa riesgos aplazados para el desarrollo de enfermedades crónicas. Las universidades tienen el deber de promover en los futuros enfermeros los conocimientos y destrezas orientados a estilos de vida saludables.Objetivo. Avaliar os estilos de vida dos estudantes de Enfermagem de uma universidade pública colombiana. Métodos. Se realizou um estudo de corte transversal em 2014. 380 alunos por autor-reporte responderam o FANTASTIC Lifestyle Assessment Questionnaire, versão adaptada ao espanhol. Resultados. A pontuação dos estilos de vida foi baixo em 9.2%, em 31.3% foi regular, em 53.7% foi bom e só em 5.8% foi fantástico. Não se detectaram diferencias estatisticamente significativas da média da pontuação total quando se comparou com sexo, faixa etária e ano de curso, mas em si em dois domínios do questionário: atividade física (pontuação maior em homens de que mulheres) e b) consumo de tabaco (médio de pontuação maior mulheres de que em homens). Conclusão. Uma proporção importante de alunos de Enfermagem da universidade pública estudada tem inadequados estilos de vida, o que significa riscos adiados para o desenvolvimento de doenças crónicas

Estilos de vida de estudiantes de Enfermería de una universidad pública colombiana

ABSTRACT: To assess the lifestyles of nursing students from a Colombian public university. Methods. A cross-sectional study was conducted in 2014. 380 students answered by self-reporting the adapted version in Spanish of FANTASTIC Lifestyles Assessment Questionnaire of Wilson and Ciliska. Results. Lifestyles were poor in 9.2%, fair in 31.3%, good in 53.7%, and excellent in only 5.8% of the participants. Statisticallysignificant differences of the total mean score were not found when comparing with gender, age group, and course year, but were detected in two domains by gender: a) physical activity (higher score in men) and b) cigarette smoking (higher score in women). Conclusion. An important proportion of our nursing students has inadequate lifestyles, which means deferred risks for the development of chronic diseases. Universities should promote the training of the future professionals in nursing with knowledge and skills aimed at healthy lifestyles.RESUMEN: Evaluar los estilos de vida de los estudiantes de Enfermería de una universidad pública colombiana. Métodos. Se realizó un estudio descriptivo de tipo trasversal en 2014. 380 alumnos por autorreporte contestaron el FANTASTIC Lifestyle Assessment Questionnaire, versión adaptada al español. Resultados. La puntuación de los estilos de vida fue bajo en el 9.2%; en el 31.3%, regular; en el 53.7%, bueno y solo en el 5.8%, fantástico. No se detectaron diferencias estadísticamente significativas del promedio de la puntuación total cuando se comparó con sexo, grupo etario y año de curso, pero en sí en dos dominios del cuestionario: actividad física (puntuación mayor en hombres que mujeres) y b) consumo de tabaco (promedio de puntuación mayor mujeres que en hombres). Conclusión. Una proporción importante de alumnos de Enfermería de la universidad pública estudiada tiene inadecuados estilos de vida, lo que significa riesgos aplazados para el desarrollo de enfermedades crónicas. Las universidades tienen el deber de promover en los futuros enfermeros los conocimientos y destrezas orientados a estilos de vida saludables

Validación española de la Escala de Agencia Personal y Empoderamiento (ESAGE-Sp-19)

Personal agency and empowerment are keys to change and social promotion, measuring them is essential for intervening with people at risk of social exclusion. The aim of this study is to develop a Spanish-short and adapted version of the Personal Agency and Empowerment Questionnaire (ESAGE) and analyze its psychometric properties. Participants were 599 university students (age, M = 24.89, SD = 6.69; 63.43% women). The model’s structure was tested through exploratory and confirmatory factorial approaches. The Confirmatory Factor Analysis showed an optimal fit for the model with a second-order factor (Personal Agency) and three first-order factors (Self-confidence, Internal Control, and Empowerment). Cronbach’s alpha values were acceptable. Stepwise multiple regression provided evidence of predictive validity, and exploratory factor analysis using the ESAGE-Sp-19 and ISP-20 scales revealed a clear and interpretable unifactorial solution. The ESAGE-Sp-19 proved to be reliable and valid in the Spanish adult population.La agencia personal y el empoderamiento son claves para el cambio y la promoción social. El objetivo de este estudio es desarrollar una versión corta y adaptada al español de la Escala de Agencia Personal y Empoderamiento (ESAGE) y analizar sus propiedades psicométricas. Los participantes fueron 599 estudiantes universitarios (edad, M = 24.89, DT = 6.69; 63.43% mujeres). La estructura delmodelo se probó a través de enfoques factoriales exploratorios y confirmatorios. El Análisis Factorial Confirmatorio (AFC) mostró un ajuste óptimo para el modelo con un Factor de segundo orden (Agencia Personal) y tres Factores de primer orden (Autoconfianza, Control Interno y Empoderamiento). Los valores alfa de Cronbach fueron aceptables. La regresión múltiple por pasos proporcionó evidencias de validez predictiva y el análisis factorial exploratorio utilizando las escalas de la ESAGE-Sp-19 y de ISP-20 reveló una solución unifactorial clara e interpretable. La ESAGE-Sp-19 se mostró fiable y válida en la población adulta española

Potential Oestrogenic Effects (Following the OECD Test Guideline 440) and Thyroid Dysfunction Induced by Pure Cyanotoxins (Microcystin-LR, Cylindrospermopsin) in Rats

Potential endocrine-disrupting properties of cyanotoxins, such as microcystin-LR (MC-LR) and cylindrospermopsin (CYN) are of concern due to their increasing occurrence, the scarcity of reports on the topic (particularly for CYN) and the impact of human's health at different levels. Thus, this work performed for the first time the uterotrophic bioassay in rats, following the Organization for Economic Cooperation and Development (OECD) Test Guideline 440, to explore the oestrogenic properties of CYN and MC-LR (75, 150, 300 μg/kg b.w./day) in ovariectomized (OVX) rats. Results revealed neither changes in the wet and blotted uterus weights nor in the morphometric study of uteri. Moreover, among the steroid hormones analysed in serum, the most remarkable effect was the dose-dependent increase in progesterone (P) levels in rats exposed to MC-LR. Additionally, a histopathology study of thyroids and serum levels of thyroids hormones were determined. Tissue affectation (follicular hypertrophy, exfoliated epithelium, hyperplasia) was observed, as well as increased T3 and T4 levels in rats exposed to both toxins. Taken together, these results point out that CYN and MC-LR are not oestrogenic compounds at the conditions tested in the uterotrophic assay in OVX rats, but, however, thyroid disruption effects cannot be discarded.Ministerio de Ciencia e Innovación PRE 2020-094412Junta de Andalucía P18-RTJ-195