Seguridad de abastecimiento energético en la Unión Europea en el contexto del conflicto gasista ruso-ucraniano

Este artículo intenta ofrecer una perspectiva general del avance del nivel de seguridad de abastecimiento energético para el gas en los Estados miembros de la Unión Europea (UE) que más compras realizan de este recurso a Rusia. Para ello se ha construido un indicador sintético: el Índice Ponderado de Seguridad Energética, que permite examinar si el grado de dicha seguridad se ha reducido en los últimos años como consecuencia del conflicto gasista ruso-ucraniano acontecido en 2006 y 2009. Los resultados ponen de manifiesto que en la mayoría de los países ha sucedido lo contrario

Seguridad de abastecimiento energético en la Unión Europea en el contexto del conflicto gasista ruso-ucraniano

This paper attempts to provide an overview of progress in the level of security of energy supply for gas in the Member States of the European Union (EU) to more purchases made this appeal to Russia. To do this we have constructed a synthetic indicator: the Weighted Index of Energy Security, which lets examine whether the degree of such security has declined in recent years as a result of the Russian-Ukrainian gas conflict occurred in 2006 and 2009. The results show that in most countries the opposite has happened.Este artículo intenta ofrecer una perspectiva general del avance del nivel de seguridad de abastecimiento energético para el gas en los Estados miembros de la Unión Europea (UE) que más compras realizan de este recurso a Rusia. Para ello se ha construido un indicador sintético: el Índice Ponderado de Seguridad Energética, que permite examinar si el grado de dicha seguridad se ha reducido en los últimos años como consecuencia del conflicto gasista ruso-ucraniano acontecido en 2006 y 2009. Los resultados ponen de manifiesto que en la mayoría de los países ha sucedido lo contrario

Modelos de crecimiento de burbujas en residuos radiactivos

Se propone un modelo para el crecimiento de burbujas de helio en material nuclear que reproduce el comportamiento cualitativo observado experimentalmente para la distribución de tamaños de burbujas. El modelo tiene estructura de sistema infinito de ecuaciones diferenciales acopladas con una restricción no local y una fuente no acotada. Se sugiere una reformulación mediante transformadas de Laplace que reduce el sistema a una ecuación integrodiferencial para la densidad de monómenos y expresa las demás densidades como convoluciones de la densidad de monómeros con núcleos aproximables por gaussianas. Esta reformulación permite establecer resultados de existencia global y obtener información sobre propiedades cualitativas, así como sobre el impacto de distintos parámetros en la evolución de la población de burbujas, fundamentales para controlar su dinámica.Ministerio de Educación y CienciaComunidad Autónoma de Madri

Adolescents’ concerns, routines, peer activities, frustration, and optimism in the time of covid-19 confinement in spain

The global outbreak of COVID-19 has brought changes in adolescents’ daily routines, restrictions to in-person interactions, and serious concerns about the situation. The purpose of this study was to explore COVID-19-related concerns, daily routines, and online peer activities during the confinement period according to sex and age groups. Additionally, the relationship of these factors and optimism along with adolescents’ frustration was examined. Participants included 1246 Spanish students aged 16–25 years old (M = 19.57; SD = 2.53; 70.8% girls). The results indicated that the top concern was their studies. COVID-19-related concerns, daily routines, and online peer activities varied by sex and age. Findings also revealed moderate to high levels of frustration, which were associated with adolescents’ main concerns, online peer activities, maintaining routines, and optimism. The results are discussed in light of their implications in designing support programs and resources to reduce the psychological impact of COVID-19 on adolescent mental health

Polymeric foams as the matrix of voltammetric sensors for the detection of catechol, hydroquinone, and their mixtures

Producción CientíficaPorous electrodes based on polymethylmethacrylate and graphite foams (PMMA_G_F) have been developed and characterized. Such devices have been successfully used as voltammetric sensors to analyze catechol, hydroquinone, and their mixtures. The presence of pores induces important changes in the oxidation/reduction mechanism of catechol and hydroquinone with respect to the sensing properties observed in nonfoamed PMMA_graphite electrodes (PMMA_G). The electropolymerization processes of catechol or hydroquinone at the electrode surface observed using PMMA_G do not occur at the surface of the foamed PMM_G_F. In addition, the limits of detection observed in foamed electrodes are one order of magnitude lower than the observed in the nonfoamed electrodes. Moreover, foamed electrodes can be used to detect simultaneously both isomers and a remarkable increase in the electrocatalytic properties shown by the foamed samples, produces a decrease in the oxidation potential peak of catechol in presence of hydroquinone, from +0.7 V to +0.3 V. Peak currents increased linearly with concentration of catechol in presence of hydroquinone over the range of 0.37·10−3 M to 1.69·10−3 M with a limit of detection (LOD) of 0.27 mM. These effects demonstrate the advantages obtained by increasing the active surface by means of porous structures.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-67482-R)Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (project VA-011U16

External validation of the GrazeIn model of pasture dry matter intake and milk yield prediction for cows managed at different calving dates and stocking rates

The aim was to evaluate the prediction accuracy of pasture dry matter intake (PDMI) and milk yield (MY) predicted by the GrazeIn model using a database representing 124 PDMI measurements at paddock level and 2232 MY measurements at cow level. External validation of the model was conducted using data collected from a trial carried out with Holstein-Friesian cows (n=72) while grazed 28 paddocks and were managed in a 2×2 factorial design by considering two calving dates (CD), with different number of days in milk (DIM), early (E, 29 DIM) vs. middle (M, 167 DIM), and two stocking rates (SR), medium (M, 3.9 cows ha-1) vs. high (H, 4.8 cows ha-1), under a rotational grazing system. Cows were randomly assigned to four grazing scenarios (EM, EH, MM and MH). The mean observed PDMI of the total database was 14.2 kg DM cow-1 day-1 while GrazeIn predicted a mean PDMI for the database of 13.8 kg DM cow-1 day-1. The mean bias was −0.4 kg DM cow-1 day-1. GrazeIn predicted PDMI for the total database with a relative prediction error (RPE) of 10.0% at paddock level. The mean observed MY of the database was 23.2 kg cow-1 day-1 while GrazeIn predicted a MY for the database of 23.1 kg cow-1 day-1. The mean bias was –0.1 kg cow-1 day-1. GrazeIn predicted MY for the total database with a mean RPE of 17.3% at cow level. For the scenarios investigated, GrazeIn predicted PDMI and MY with a low level of error which made it a suitable tool for decision support systemsINIA (project RTA2005-00204-00 and the complementary PhD fellowship granted to AIRF for her stay at the INRA-St. Gilles, Rennes, where the experimental database collected at the CIAM was evaluated using GrazeIn)S

In Vitro Mutagenic and Genotoxic Assessment of a Mixture of the Cyanotoxins Microcystin-LR and Cylindrospermopsin

The co-occurrence of various cyanobacterial toxins can potentially induce toxic effects different than those observed for single cyanotoxins, as interaction phenomena cannot be discarded. Moreover, mixtures are a more probable exposure scenario. However, toxicological information on the topic is still scarce. Taking into account the important role of mutagenicity and genotoxicity in the risk evaluation framework, the objective of this study was to assess the mutagenic and genotoxic potential of mixtures of two of the most relevant cyanotoxins, Microcystin-LR (MC-LR) and Cylindrospermopsin (CYN), using the battery of in vitro tests recommended by the European Food Safety Authority (EFSA) for food contaminants. Mixtures of 1:10 CYN/MC-LR (CYN concentration in the range 0.04-2.5 µg/mL) were used to perform the bacterial reverse-mutation assay (Ames test) in Salmonella typhimurium, the mammalian cell micronucleus (MN) test and the mouse lymphoma thymidine-kinase assay (MLA) on L5178YTk± cells, while Caco-2 cells were used for the standard and enzyme-modified comet assays. The exposure periods ranged between 4 and 72 h depending on the assay. The genotoxicity of the mixture was observed only in the MN test with S9 metabolic fraction, similar to the results previously reported for CYN individually. These results indicate that cyanobacterial mixtures require a specific (geno)toxicity evaluation as their effects cannot be extrapolated from those of the individual cyanotoxins.España Ministerio de Economía y Competitividad AGL2015-64558-

External validation of the GrazeIn model of pasture dry matter intake and milk yield prediction for cows managed at different calving dates and stocking rates

The aim was to evaluate the prediction accuracy of pasture dry matter intake (PDMI) and milk yield (MY) predicted by the GrazeIn model using a database representing 124 PDMI measurements at paddock level and 2232 MY measurements at cow level. External validation of the model was conducted using data collected from a trial carried out with Holstein-Friesian cows (n=72) while grazed 28 paddocks and were managed in a 2×2 factorial design by considering two calving dates (CD), with different number of days in milk (DIM), early (E, 29 DIM) vs. middle (M, 167 DIM), and two stocking rates (SR), medium (M, 3.9 cows ha-1) vs. high (H, 4.8 cows ha-1), under a rotational grazing system. Cows were randomly assigned to four grazing scenarios (EM, EH, MM and MH). The mean observed PDMI of the total database was 14.2 kg DM cow-1 day-1 while GrazeIn predicted a mean PDMI for the database of 13.8 kg DM cow-1 day-1. The mean bias was −0.4 kg DM cow-1 day-1. GrazeIn predicted PDMI for the total database with a relative prediction error (RPE) of 10.0% at paddock level. The mean observed MY of the database was 23.2 kg cow-1 day-1 while GrazeIn predicted a MY for the database of 23.1 kg cow-1 day-1. The mean bias was –0.1 kg cow-1 day-1. GrazeIn predicted MY for the total database with a mean RPE of 17.3% at cow level. For the scenarios investigated, GrazeIn predicted PDMI and MY with a low level of error which made it a suitable tool for decision support systems