The flip teaching as tool to improving students’ sustainable learning performance in a financial course

Flip teaching (FT) is a methodology with a significant impact on the educational innovation trend that encourages active learning and facilitates the learning of students. The main objective of this study is to measure the impact of flip teaching on the learning of a course at a higher education institution. To analyze the differences in the exam marks between students that follow FT and other methodologies, the t-statistic and Mann–Whitney U test have been used. Results indicate that FT allows improving the performance of students and achieving collateral capacities, such as responsibility and awareness, making learning more sustainable. This study makes an interesting contribution to existing research in education and demonstrates that it is possible to introduce FT in a block of the course and can be transferable to other courses

Prescribed fires

Fire is a natural disturbance phenomenon. Despite recognition of the importance of fire in ecosystems, fire suppression policies have been favoured, contributing to the accumulation of fuel in wildlands. Political options coupled with land abandonment, livestock reduction, plantation of monospecific species and the increasing number and length of summer droughts, as a consequence of climate change, are responsible for the occurrence of severe wildfires such as occurred in 2017 in Portugal and California. These kinds of fires have tremendous and unwanted impacts on the environment, society and the economy, including ecosystem services degradation and the loss of life (Nadal-Romero et al., 2018; Pereira et al., 2016a, Pereira et al., 2018). To tackle this problem, more investments are needed in preventive measures such as forest management techniques to reduce the amount of biomass in wildland environments. The most commonly used are mechanical thinning (e.g. clearcutting, partial cutting) and, if authorized by government bodies, prescribed fires ..

Vector magnetic hysteresis of hard superconductors

Critical state problems which incorporate more than one component for the magnetization vector of hard superconductors are investigated. The theory is based on the minimization of a cost functional ${\cal C}[\vec{H}(\vec{x})]$ which weighs the changes of the magnetic field vector within the sample. We show that Bean's simplest prescription of choosing the correct sign for the critical current density $J_c$ in one dimensional problems is just a particular case of finding the components of the vector $\vec{J}_c$. $\vec{J}_c$ is determined by minimizing ${\cal C}$ under the constraint $\vec{J}\in\Delta (\vec{H},\vec{x})$, with $\Delta$ a bounded set. Upon the selection of different sets $\Delta$ we discuss existing crossed field measurements and predict new observable features. It is shown that a complex behavior in the magnetization curves may be controlled by a single external parameter, i.e.: the maximum value of the applied magnetic field $H_m$.Comment: 10 pages, 9 figures, accepted in Phys. Rev.

Fire effects on biochemical properties of a semiarid pine forest topsoil at cm-scale

Forest fires can greatly affect soil properties and processes. In the study of the fire effects on soil, the soil thickness affected by heat depends on the characteristics of the fire and soil itself, but also on the attribute to be measured. The objective of this work is to know to what thickness (up to 1, 2 or 3 cm) various sensitive soil properties are immediately affected by a controlled burning. To achieve this aim, unaltered fresh topsoil (mollic horizon) of a fire-prone Aleppo pine forest in the semiarid Ebro Valley (NE-Spain) were sampled and, without destroying their original structure, burned from the surface in an outdoor combustion tunnel in triplicate. Biological properties are measured, including basal and normalized soil respiration (bSR and nSR), β-D-glucosidase (GLUase) and phosphomonoestarase (PHOase) activities, and related parameters, such as total organic matter (TOM), oxidizable organic C (OxC), nonhydrolyzable carbon (NHC), P-Olsen, pH, soil moisture and soil water repellency (WR). In the unburned soil, most of these properties showed a decreasing gradient with depth which is modified after burning, in some cases inverted (as enzymatic activities and WR), in others intensified (P-Olsen) and in most, truncated, with a maximum value in the second cm. The depth of the soil in which changes were recorded varied according to the attibute considered; thus, burning significantly decreased only up to the first cm: bSR (73 %) and TOM (81 %), up to 2 cm: PHOase (89 %), OxC (17 %) and WR (96 %) and up to 3 cm depth GLUase (58 %), NHC (24 %) and moisture (73 %). However, P-Olsen and pH both increased after burning up to 1 and 3 cm soil depths, with increases of up to 240 % and 11 %, respectively. In conclusion, fire effects on soil are depth dependent, and this dependency is not uniform across soil properties

Critical state theory for nonparallel flux line lattices in type-II superconductors

Coarse-grained flux density profiles in type-II superconductors with non-parallel vortex configurations are obtained by a proposed phenomenological least action principle. We introduce a functional $C[H(x)]$, which is minimized under a constraint of the kind $J$ belongs to $Delta$ for the current density vector, where $Delta$ is a bounded set. This generalizes the concept of critical current density introduced by C. P. Bean for parallel vortex configurations. In particular, we choose the isotropic case ($Delta$ is a circle), for which the field penetration profiles $H(x,t)$ are derived when a changing external excitation is applied. Faraday's law, and the principle of minimum entropy production rate for stationary thermodynamic processes dictate the evolution of the system. Calculations based on the model can reproduce the physical phenomena of flux transport and consumption, and the striking effect of magnetization collapse in crossed field measurements.Comment: The compiled TeX document length is 10 pages. Two figures (one page each) are also included The paper is accepted for publication in Phys. Rev. Let

Analysing the effect of land use and vegetation cover on soil infiltration in three contrasting environments in Northeast Spain

Este estudio presenta el análisis conjunto de la información obtenida a partir de 195 ensayos de infiltración en el campo, que fueron realizados mediante dispositivos de doble anillo. Los experimentos se realizaron en 20 situaciones contrastadas de usos del suelo, los cuales se encuentran distribuidos en tres contextos geográficos (costa NE de Cataluña, monte bajo del sector central del valle del Ebro y montaña media de la vertiente Sur del Pirineo central). El objetivo de esta investigación es determinar los factores más importantes que explican la variabilidad de la infiltración: uso del suelo, tipo de cubierta vegetal, características del suelo y del substrato rocoso, humedad del suelo y altitud. El análisis de los datos se realizó mediante la comparación de las variables a partir de distintos métodos estadísticos: test de correlación lineal bivariada, ANOVA y comparaciones múltiples de Bonferroni. Los resultados muestran que la variabilidad de la infiltración está principalmente asociada al tipo de uso del suelo, siendo el factor más determinante. El tipo de cubierta vegetal se mostró como el segundo factor en importancia, mientras la humedad del suelo no presentó correlación con la infiltración. La interpretación de estos resultados sugiere que las características de las áreas de estudio son más determinantes que las variaciones temporales del estado hídrico del suelo, aunque la humedad pueda tener un grado de influencia mayor o menor en cada uso del suelo. La validez de los resultados obtenidos en este estudio está avalada porque se ha analizado un amplio espectro de escenarios de uso del suelo/cubierta vegetal, incluso teniendo en cuenta que se han comparado zonas con distintas características geográficas y geológicas. This study presents a joint analysis of the information from 195 field infiltration experiments, using double ring devices. The experiments were carried out in 20 contrasting types of land use, distributed across three geographic contexts (coast of NE Catalonia, low mountains in the central Ebro Valley and mid-height mountains from the southern range of the Central Pyrenees). The objective of this research was to determine the most important factors explaining infiltration variability: land use, type of vegetation cover, soil and bedrock characteristics, soil moisture and altitude. Data analysis was performed by comparing variables using statistical methods: bivariate lineal correlation, ANOVA and Bonferroni multiple comparison tests. Results show that infiltration variability is the most important factor and mainly linked to land use, followed by vegetation type. In contrast, soil moisture did not show any relation with infiltration. The interpretation of these results suggests that the characteristics of the study areas are more decisive than temporal variations of soil water content, although humidity can influence land use to a greater or lesser degree. The validity of the results obtained in this study is supported by the wide range of land use and land cover analysed, located in areas with different geographical and geological characteristics

Esofagitis eosinofílica, eficacia de las alternativas terapéuticas en el adulto: revisión sistemática

Fundamentos: La esofagitis eosinofílica es hoy en día la principal causa de disfagia en el adulto. La elección de la terapia se debe consensuar con el paciente. El objetivo de este trabajo fue revisar la bibliografía científica para conocer la eficacia de las distintas opciones terapéuticas de la esofagitis eosinofílica en el adulto. Métodos: Se realizó una búsqueda de artículos durante el mes de febrero de 2023 en las bases de datos de PubMed, Web of Science, Scopus y Scielo, empleando los términos de búsqueda eosinophilic esophagitis, therapeutics y treatment, seleccionándose los ensayos clínicos y estudios observacionales publicados en los últimos diez años en adultos. Resultados: Se obtuvieron un total de 1.138 artículos, de los cuales 41 fueron seleccionados tras aplicar los criterios de elegibilidad. De las terapias disponibles, el tratamiento más frecuentemente analizado fueron los corticoides deglutidos, seguido de las dietas de eliminación y de los inhibidores de la bomba de protones, predominando los ensayos clínicos. Los estudios arrojan resultados sobre la eficacia de estas terapias en la remisión histológica y clínica, tanto en la inducción como a largo plazo. Conclusiones: Existen fundamentalmente tres terapias en la esofagitis eosinofílica en el adulto, siendo todas superiores frente a placebo en respuesta histológica y clínica