Galactic magnetic fields and the large-scale anisotropy at MILAGRO

The air-shower observatory Milagro has detected a large-scale anisotropy of unknown origin in the flux of TeV cosmic rays. We propose that this anisotropy is caused by galactic magnetic fields, in particular, that it results from the combined effects of the regular and the turbulent (fluctuating) magnetic fields in our vicinity. Instead of a diffusion equation, we integrate Boltzmann's equation to show that the turbulence may define a preferred direction in the cosmic-ray propagation that is orthogonal to the local regular magnetic field. The approximate dipole anisotropy that we obtain explains well Milagro's data.Comment: 12 pages, version to appear in ApJ

Is it possible to reach a sustainable change in Science Teaching at primary schools? A plan for achieving it

One of the great challenges of recent decades, which has been the subject of much debate and research, is how to bridge the gap between science education research and school practice. To address this issue, we have reviewed and analysed in depth the characteristics that in-service teacher training programmes should have in order to be effective and of high quality. In this paper, we present a professional development programme to achieve the desired didactic change in science teaching at schools. This programme is organized into phases that can be evaluated by measurable indicators to determine its success or failure. In addition, in order to assess the sustainability of change in a school (or group of teachers), we have incorporated the theory of critical mass in social change, which has received recent empirical support.This work was supported by the Ministry of Education, Culture and Sport in Spain within the State Programme for the Promotion of Talent and its Employability (Subprogramme for the Training of University Teachers) under grant number FPU15/02678 and by Physics Education Research at University GIREP Group

Decision Tree Ensemble Method for Analyzing Traffic Accidents of Novice Drivers in Urban Areas

Presently, there is a critical need to analyze traffic accidents in order to mitigate their terrible economic and human impact. Most accidents occur in urban areas. Furthermore, driving experience has an important effect on accident analysis, since inexperienced drivers are more likely to suffer fatal injuries. This work studies the injury severity produced by accidents that involve inexperienced drivers in urban areas. The analysis was based on data provided by the Spanish General Traffic Directorate. The information root node variation (IRNV) method (based on decision trees) was used to get a rule set that provides useful information about the most probable causes of fatalities in accidents involving inexperienced drivers in urban areas. This may prove useful knowledge in preventing this kind of accidents and/or mitigating their consequences.his work has been supported by the Spanish “Ministerio de Economía y Competitividad” and by “Fondo Europeo de Desarrollo Regional” (FEDER) under Project TEC2015-69496-R

Using extreme prior probabilities on the Naive Credal Classifier

The Naive Credal Classifier (NCC) was the first method proposed for Imprecise Classification. It starts from the known Naive Bayes algorithm (NB), which assumes that the attributes are independent given the class variable. Despite this unrealistic assumption, NB and NCC have been successfully used in practical applications. In this work, we propose a new version of NCC, called Extreme Prior Naive Credal Classifier (EP-NCC). Unlike NCC, EP-NCC takes into consideration the lower and upper prior probabilities of the class variable in the estimation of the lower and upper conditional probabilities. We demonstrate that, with our proposed EP-NCC, the predictions are more informative than with NCC without increasing the risk of making erroneous predictions. An experimental analysis carried out in this work shows that EP-NCC significantly outperforms NCC and obtains statistically equivalent results to the algorithm proposed so far for Imprecise Classification based on decision trees, even though EP-NCC is computationally simpler. Therefore, EP-NCC is more suitable to be applied to large datasets for Imprecise Classification than the methods proposed so far in this field. This is an important issue in favor of our proposal due to the increasing amount of data in every area.This work has been supported by UGR-FEDER funds under Project A-TIC-344-UGR20, by the “FEDER/Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades ” under Project P20_00159, and by research scholarship FPU17/02685

Is it feasible to change science teaching in primary education?

Algunos autores consideran que el cambio didáctico en la enseñanza de las ciencias en primaria es una tarea imposible. Efectivamente, se trata de un proceso sobre el que se ha investigado poco y poco sistemáticamente. Por ello, se presenta un plan –justificado en la investigación sobre formación en activo y en la teoría de la masa crítica para el cambio en las convenciones sociales– para conseguir el cambio didáctico a partir de la colaboración entre un equipo universitario y el equipo docente y directivo de una escuela. Se justifican sus distintas fases, se definen indicadores para valorarlas y se muestran los resultados de su desarrollo.Some authors consider that the didactic change in primary science education is an impossible task. Indeed, systematic research on this process is still scarce. For this reason, we present a plan, based on research on in-service professional development and in the theory of critical mass for change in social conventions, to achieve didactic change, based on collaboration between a university research team and teaching and principal of a school. We justify the different phases of the plan, define the indicators to evaluate them and show the results of its development

Bagging of Credal Decision Trees for Imprecise Classification

The Credal Decision Trees (CDT) have been adapted for Imprecise Classification (ICDT). However, no ensembles of imprecise classifiers have been proposed so far. The reason might be that it is not a trivial question to combine the predictions made by multiple imprecise classifier. In fact, if the combination method used is not appropriate, the ensemble method could even worse the performance of one single classifier. On the other hand, the Bagging scheme has shown to provide satisfactory results in precise classification, specially when it is used with CDTs, which are known to be very weak and unstable classifiers. For these reasons, in this research, it is proposed a new Bagging scheme with ICDTs. It is presented a new technique for combining predictions made by imprecise classifiers that tries to maximize the precision of the bagging classifier. If the procedure for such a combination is too conservative it is easy to obtain few information and worse the results of a single classifier. Our proposal considers only the states with the minimum level of non-dominance. An exhaustive experimentation carried out in this work has shown that the Bagging of ICDTs, with our proposed combination technique, performs clearly better than a single ICDT.This work has been supported by the Spanish “Ministerio de Economía y Competitividad” and by “Fondo Europeo de Desarrollo Regional” (FEDER) under Project TEC2015-69496-R

La orientación del patio del colegio: un ejemplo para la indagación sobre Geografía en Educación Primaria

Realizamos una propuesta didáctica para organizar el patio del colegio a partir de la obtención de datos empíricos sobre los movimientos observables del Sol desde un lugar concreto en el planeta. Si bien, los niños pueden conocer la existencia y uso de la brújula para ubicar los puntos cardinales, la idea es que ellos lleguen a construir su propia brújula a partir del movimiento del Sol, utilizando un enfoque constructivista de la enseñanza de las ciencias experimentales. Una vez dibujada esta brújula, ésta puede ser utilizada para realizar otras actividades de indagación. Presentamos detalladamente los materiales y la propuesta de actividades encaminadas a la construcción de esta brújula

Association of increased plasma cardiotrophin-1 with inappropriate left ventricular mass in essential hypertension

Inappropriate left ventricular mass is present when the value of left ventricular mass exceeds individual needs to compensate hemodynamic load imposed by increased blood pressure. The goal of this study was to investigate whether plasma concentration of cardiotrophin-1, a cytokine that induces exaggerated hypertrophy in cardiomyocytes with hypertensive phenotype, is related to inappropriate left ventricular mass in patients with essential hypertension. The study was performed in 118 patients with never-treated hypertension and without prevalent cardiac disease. The left ventricular mass prediction from stroke work (systolic blood pressurexDoppler stroke volume), sex, and height (in meters(2.7)) was derived. An observed left ventricular mass/predicted left ventricular mass value >128% defined inappropriate left ventricular mass. Plasma cardiotrophin-1 was measured by an enzyme-linked immunosorbent assay. The studies were repeated in a group of 45 patients after 1 year of antihypertensive treatment. At baseline 67 and 51 patients presented with appropriate and inappropriate left ventricular mass, respectively. Plasma cardiotrophin-1 was higher (P<0.001) in patients with inappropriate mass than in patients with appropriate mass and normotensive controls. A direct correlation was found between cardiotrophin-1 and observed left ventricular mass/predicted left ventricular mass ratio (r=0.330, P<0.001) in all hypertensive patients. After treatment, plasma cardiotrophin-1 decreased and increased in patients in which inappropriate left ventricular mass regressed and persisted, respectively, despite a similar reduction of blood pressure in the 2 subgroups of patients. Albeit descriptive in nature, these results suggest the hypothesis that an excess of cardiotrophin-1 may contribute to inappropriate left ventricular growth in hypertensive patients

El conflicto entre Rusia y Ucrania y sus efectos sobre los sistemas agroalimentarios

El conflicto armado entre Rusia y Ucrania ha desencadenado el cierre de puertos y prácticamente la paralización de actividades económicas en Ucrania, así como sanciones económicas internacionales a Rusia, entre las que se encuentran restricciones al comercio y exclusión parcial de bancos rusos del sistema de transacciones financieras SWIFT, junto con la pandemia del Covid-19, ha generado que los productos y servicios tengan una inflación alrededor del mundo. Por esto el comercio agroalimentario de América Latina y el Caribe se verá poco afectado, al menos directamente. La interrupción de las exportaciones de Rusia puede provocar el redireccionamiento del comercio y abrir una oportunidad de exportación principalmente para países exportadores de productos de la molinería, cereales, grasas y aceites y semillas oleaginosas. Se han generado 4 canales de transmisión; el primero es el de las restricciones al comercio agroalimentario, el segundo canal o vía de transmisión de los efectos de la crisis es el comercio y los precios de los fertilizantes, el tercer canal de transmisión de la crisis es la aceleración de los aumentos en los precios internacionales de productos básicos y por último el cuarto canal de transmisión de la crisis corresponde a los aumentos en los precios de la energía

Micelles of Progesterone for Topical Eye Administration: Interspecies and Intertissues Differences in Ex Vivo Ocular Permeability

Progesterone (PG) may provide protection to the retina during retinitis pigmentosa, but its topical ocular supply is hampered by PG poor aqueous solubility and low ocular bioavailability. The development of efficient topical ocular forms must face up to two relevant challenges: Protective barriers of the eyes and lack of validated ex vivo tests to predict drug permeability. The aims of this study were: (i) To design micelles using Pluronic F68 and Soluplus copolymers to overcome PG solubility and permeability; and (ii) to compare drug diffusion through the cornea and sclera of three animal species (rabbit, porcine, and bovine) to investigate interspecies differences. Micelles of Pluronic F68 (3–4 nm) and Soluplus (52–59 nm) increased PG solubility by one and two orders of magnitude, respectively and exhibited nearly a 100% encapsulation efficiency. Soluplus systems showed in situ gelling capability in contrast to the low viscosity Pluronic F68 micelles. The formulations successfully passed the hen’s egg-chorioallantoic membrane test (HET-CAM) test. PG penetration through rabbit cornea and sclera was faster than through porcine or bovine cornea, although the differences were also formulation-dependent. Porcine tissues showed intermediate permeability between rabbit and bovine. Soluplus micelles allowed greater PG accumulation in cornea and sclera whereas Pluronic F68 promoted a faster penetration of lower PG dosesThis research was funded by MINECO [SAF2017-83118-R] (Spain), Agencia Estatal de Investigación (AEI, Spain), Xunta de Galicia [AEMAT ED431E 2018/08], and European Regional Development Fund (FEDER). Predoctoral grants CEU Cardenal Herrera University FPI CEU-UCH, mobility grant CEINDO international doctoral school, CEU-Cardenal Herrera University [INDI 19/28]S