Electroweak phase transition in a model with gauged lepton number

In this work we study the electroweak phase transition in a model with gauged lepton number. Here, a family of vector-like leptons is required in order to cancel the gauge anomalies. Furthermore, these leptons can play an important role in the transition process. We find that this framework is able to provide a strong transition, but only for a very limited number of cases.Comment: 14 pages, 5 figures, matches published versio

Peninsular fibulae: elbow «sículas» or type «Monachil»? News and revision

Se estudia un amplio conjunto de fibulas de codo de las tradicionalmente denominadas «sículas», bajo nuestra nomenclatura de tipo «Monachil», que vienen a completar el panorama cada vez más conocido de este tipo de artilugios problemáticos y paradigmáticos del Bronce Final en la Península Ibérica. De nuevo, se profundiza en sus diferentes tipologías y cronologías, así como en su dispersión regional y posible autoctonía o aloctonía, con el fin de seguir incidiendo en la elaboración de un factible marco crono-cultural, en el que encuadrar mínimamente sus mal definidas formas y desarrollos. Con los datos actuales no es factible mantener un origen sículo para estas fíbulas en la Península Ibérica.We study a wide range of elbow fibulae, traditionally referred to as «sículas» in our Monachil nomenclature. This study will fulfill our knowledge of these problematic and paradigmatic devices in the Late Bronze in the Iberian Peninsula. The different typologies and chronologies are deeply analyzed, as well as their regional distribution, focusing on their native or foreign origin. Our aim is to build a chrono-cultural framework incorporating these fibulae. With the current information available, we cannot conclude that these Iberian fibulae have a Sicilian origin

Origen y desarrollo del totalitarismo en el Estado moderno

A lo largo de los dos últimos siglos se han contemplado distintas formas de gobierno. Democracias, dictaduras militares y totalitarismos han tenido lugar, de manera incluso simultánea, en Europa y han mostrado diferentes interpretaciones que la época Moderna hace sobre el poder y el Estado. El presente ensayo busca analizar qué se entiende por movimiento totalitario, cómo surge una administración con estas características y cuáles son sus implicaciones en la vida pública de la sociedad en la que se desarrolla. Es decir, estudiar cómo es posible que una forma de gobierno que promueve la alienación del ser humano logre alcanzar el poder en un periodo que se dice moderno. El totalitarismo surge por un deterioro en el sistema político. Por ello es relevante analizar cuáles han sido los pasos que han hecho viable la aparición de partidos políticos que ansíen la dominación total. Esta cuestión ha sido abordada por distintos autores que han analizado, sin lugar a duda, de forma brillante y exhaustiva la forma de gobierno totalitaria. En particular destaca el trabajo de Hannah Arendt recogido en su obra El origen de los totalitarismos y de William Ebenstein, en su título El totalitarismo. También es preciso mencionar las investigaciones de Raymond Aron y Franz Neumann, ya que sus indagaciones permiten encuadrar el fenómeno del totalitarismo en el contexto político en el que surgen. Proporcionan un análisis sobre la situación de las formas de gobierno anteriores al ascenso de los movimientos totalitarios que se vuelve necesario para entender la raíz de esta forma de gobierno. El objetivo de este escrito persigue analizar las condiciones de posibilidad del partido totalitario, su ascenso al poder y los elementos que lo componen y le permiten mantener el control de la sociedad. Ciertamente es digno de estudio que una fórmula de gobierno basada en la represión de la población en su conjunto perdure en una posición de mando. Para ello, la metodología que se mantiene a lo largo de la investigación pretende recorrer la trayectoria que tienen los postulados totalitarios desde el momento en el que se hace posible su génesis, a saber, en el cambio de paradigma que la Modernidad trae consigo en el concepto del poder político. En este sentido, debe considerarse, en primer lugar, la lectura que la política moderna hace sobre el ser humano, la utilidad de las agrupaciones políticas y los objetivos Eduardo Jiménez Zorita 2 que persigue el Estado. Las administraciones modernas manifiestan una extremada complejidad en su forma, con un gran entramado burocrático; pero una enorme facilidad para ser dominadas por agrupaciones absolutistas. En este contexto se debe analizar el surgimiento del totalitarismo, que aparece como una fuerza revolucionaria y salvadora. A pesar de que el movimiento tiránico se presenta bajo distintas apariencias, en función de la nación en la que se desarrolla, todas ellas obedecen a una suerte de patrón que permite detectar los elementos comunes. Entonces es viable extraer y examinar los rasgos propios que presenta dicha forma de gobierno, para poder inferir las consecuencias que un régimen de este tipo produce en la política y en población a la que somete

Small farmers' perception of factors influencing regional chemical control of Diaphorina citri

Regional Control Areas (RCAs) have been implemented in Mexico as a strategy to delay the spread of Candidatus Liberibacter asiaticus, the causal bacterium of the disease known as Huanglongbing (HLB). The implementation of an effective management of the vector insect, Diaphorina citri in the RCAs requires the knowledge, acceptance and coordinated engagement of small agricultural producers. This research assessed the perception and knowledge of 62 citrus growers regarding the operational, sociocultural and environmental factors influencing chemical control of D. citri in four RCAs within Veracruz State. According to their responses, the following factors have been identified as the operational factors with the highest influence on the effectiveness of insecticides against D. citri within RCAs: the lack of knowledge about the use of surfactants, application speed, poor calibration of sprayers and incorrect water quality. The most significant sociocultural factors are the general unawareness of the pest and the safe and proper application of pesticides. The most relevant environmental factors during application: temperature, relative humidity, and wind speed. Sociocultural index correlated with the perception of effectiveness. Therefore, it becomes necessary to consider differences among citrus growers in each region and setting out the most appropriatestrategies for vector and disease management. Highlights Some operational practices that citrus growers are not aware of may influence their perception of chemical control. The sociocultural context of growers determines their decision-taking on insecticide applications. During the application of insecticides in regional control areas (RCAs), growers do not take into account weather conditions. The effective management of D. citri requires a coordinated engagement of small growers' in RCAs.Regional Control Areas (RCAs) have been implemented in Mexico as a strategy to delay the spread of Candidatus Liberibacter asiaticus, the causal bacterium of the disease known as Huanglongbing (HLB). The implementation of an effective management of the vector insect, Diaphorina citri in the RCAs requires the knowledge, acceptance and coordinated engagement of small agricultural producers. This research assessed the perception and knowledge of 62 citrus growers regarding the operational, sociocultural and environmental factors influencing chemical control of D. citri in four RCAs within Veracruz State. According to their responses, the following factors have been identified as the operational factors with the highest influence on the effectiveness of insecticides against D. citri within RCAs: the lack of knowledge about the use of surfactants, application speed, poor calibration of sprayers and incorrect water quality. The most significant sociocultural factors are the general unawareness of the pest and the safe and proper application of pesticides. The most relevant environmental factors during application: temperature, relative humidity, and wind speed. Sociocultural index correlated with the perception of effectiveness. Therefore, it becomes necessary to consider differences among citrus growers in each region and setting out the most appropriatestrategies for vector and disease management. Highlights Some operational practices that citrus growers are not aware of may influence their perception of chemical control. The sociocultural context of growers determines their decision-taking on insecticide applications. During the application of insecticides in regional control areas (RCAs), growers do not take into account weather conditions. The effective management of D. citri requires a coordinated engagement of small growers' in RCAs

Luminescent Devices Based on Silicon-Rich Dielectric Materials

Luminescent silicon‐rich dielectric materials have been under intensive research due to their potential applications in optoelectronic devices. Silicon‐rich nitride (SRN) and silicon‐rich oxide (SRO) films have been mostly studied because of their high luminescence and compatibility with the silicon-based technology. In this chapter, the luminescent characteristics of SRN and SRO films deposited by low‐pressure chemical vapor deposition are reviewed and discussed. SRN and SRO films, which exhibit the strongest photoluminescence (PL), were chosen to analyze their electrical and electroluminescent (EL) properties, including SRN/SRO bilayers. Light emitting capacitors (LECs) were fabricated with the SRN, SRO, and SRN/SRO films as the dielectric layer. SRN‐LECs emit broad EL spectra where the maximum emission peak blueshifts when the polarity is changed. On the other hand, SRO‐LECs with low silicon content (~39 at.%) exhibit a resistive switching (RS) behavior from a high conduction state to a low conduction state, which produce a long spectrum blueshift (~227 nm) between the EL and PL emission. When the silicon content increases, red emission is observed at both EL and PL spectra. The RS behavior is also observed in all SRN/SRO‐LECs enhancing an intense ultraviolet EL. The carrier transport in all LECs is analyzed to understand their EL mechanism

Physicochemical characteristics, minerals, phenolic compounds, and antioxidant capacity in fig tree fruits with macronutrient deficiencies

In this research, effects of macronutrient deficiency (N, P, K, Ca, and Mg) on the production, physicochemical characteristics, minerals, phenolic compounds, and antioxidant capacity of fig fruits (Ficus carica L.) were evaluated using the missing element technique in a controlled hydroponic system under greenhouse conditions. N-deficient plants had no fruit production, while fruits with absence of P, K, and Ca were the most affected in terms of size, weight, and physicochemical characteristics. On the other hand, the concentration of minerals was significantly different (p<0.05), finding some interactions of synergism and antagonism between ions. Phenolic compounds increased in fruits with P and Ca deficiency, as well as the antioxidant capacity DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) in the fruits of the treatment -Ca. Regarding the FRAP (ferric reducing antioxidant power) test, higher values were found for all treatments without minerals (-P, -K, -Ca, and -Mg) with respect to the control. The results obtained explain the responses of the fig tree subjected to nutritional deficiencies

The role of selenium mineral trace element in exercise: antioxidant defense system, muscle performance, hormone response, and athletic performance. A systematic review

Exercise overproduces oxygen reactive species (ROS) and eventually exceeds the body’s antioxidant capacity to neutralize them. The ROS produce damaging effects on the cell membrane and contribute to skeletal muscle damage. Selenium (Se), a natural mineral trace element, is an essential component of selenoproteins that plays an important role in antioxidant defense. The activity of the enzyme glutathione peroxidase (GPx), a highly-efficient antioxidant enzyme, is closely dependent on the presence of Se. These properties of Se may be potentially applicable to improve athletic performance and training recovery. We systematically searched for published studies to evaluate the effectiveness of Se supplementation on antioxidant defense system, muscle performance, hormone response, and athletic performance among physically active individuals. We used the Preferred Reporting Elements for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and searched in SCOPUS, Web of Science (WOS), and PubMed databases to identify published studies until March 2020. The systematic review incorporated original studies with randomized controlled crossover or parallel design in which intake of Se administered once a day was compared with the same placebo conditions. No exclusions were applied for the type of physical exercise performed, the sex, nor the age of the participants. Among 150 articles identified in the search, 6 met the criteria and were included in the systematic review. The methodological quality of the studies was evaluated using the McMaster Critical Review Form. Oral Se supplementation with 180 µg/day or 240 µg/day (selenomethionine) and 200 µg/day (Sodium Selenite), significantly decreased lipid hydroperoxide levels and increased GPx in plasma, erythrocyte, and muscle. No significant effects were observed on athletic performance, testosterone hormone levels, creatine kinase activity, and exercise training-induced adaptations on oxidative enzyme activities or on muscle fiber type myosin heavy chain expression. In addition, Se supplementation showed to have a dampening effect on the mitochondria changes in chronic and acute exercise. In summary, the use of Se supplementation has no benefits on aerobic or anaerobic athletic performance but it may prevent Se deficiencies among athletes with high-intensity and high-volume training. Optimal Se plasma levels may be important to minimize chronic exercise-induced oxidative effects and modulate the exercise effect on mitochondrial changes

Phenol photocatalytic degradation over Fe-TiO2 materials synthesized by different methods

The photocatalytic activity and stability of 3% Fe-TiO2 materials synthesized by incipient wet impregnation (% Fe-TiO2-DP25) and sol-gel (3% Fe-TiO2-sol-gel) were studied using the phenol degradation as test reaction. The effects of various operation parameters including photocatalyst concentration, solution pH and initial H2O2 concentration on phenol degradation were also investigated. The higher phenol degradation was achieved using 26 mg of photocatalyst, H2O2 initial concentration of 600 mg/l and initial pH of 3.0 with both materials. It was found that 3% Fe-TiO2-DP25 enhanced activity, achieving a 99% phenol degradation, in comparison with 70% phenol degradation with the 3% Fe-TiO2-sol-gel. Notwithstanding, the material prepared by incipient wet impregnation method, evidenced leaching of iron ions from the material surface. Therefore, this catalyst is not suitable for the phenol degradation for environmental and economic reasons. The catalyst prepared by the sol-gel method did not show iron leaching during the reaction and maintain its catalytic activity after several reuses.Se estudió la actividad fotocatalítica y estabilidad de materiales 3% Fe/TiO2 sintetizados por impregnación húmeda incipiente (3% Fe/TiO2-DP25) y sol-gel (3% Fe/TiO2-sol-gel), usando fenol como molécula modelo. Se evaluó el efecto de parámetros de operación como concentración de fotocatalizador, H2O2 y pH de la solución. Los mayores porcentajes de degradación de fenol con ambos materiales se lograron utilizando 26 mg de fotocatalizador y 600 Mg/Ll de H2O2 a un pH de 3.0. El mejor porcentaje de degradación de fenol (99%) se obtuvo usando el catalizador 3% Fe/TiO2-DP25, en comparación a un 70% con el material 3% Fe/TiO2-sol-gel. No obstante, el material preparado por impregnación húmeda incipiente fue inestable evidenciando lixiviación de hierro. Por lo tantio, este catalizador no es adecuado para la degradación de fenol debido a razones ambientales y económicas. El catalizador preparado por sol-gel no mostró lixiviación de hierro durante la reacción y mantuvo su actividad y estabilidad catalítica después de varios reúsos

Phenol photocatalytic degradation over Fe-TiO2 materials synthesized by different methods

The photocatalytic activity and stability of 3% Fe-TiO2 materials synthesized by incipient wet impregnation (% Fe-TiO2-DP25) and sol-gel (3% Fe-TiO2-sol-gel) were studied using the phenol degradation as test reaction. The effects of various operation parameters including photocatalyst concentration, solution pH and initial H2O2 concentration on phenol degradation were also investigated. The higher phenol degradation was achieved using 26 mg of photocatalyst, H2O2 initial concentration of 600 mg/l and initial pH of 3.0 with both materials. It was found that 3% Fe-TiO2-DP25 enhanced activity, achieving a 99% phenol degradation, in comparison with 70% phenol degradation with the 3% Fe-TiO2-sol-gel. Notwithstanding, the material prepared by incipient wet impregnation method, evidenced leaching of iron ions from the material surface. Therefore, this catalyst is not suitable for the phenol degradation for environmental and economic reasons. The catalyst prepared by the sol-gel method did not show iron leaching during the reaction and maintain its catalytic activity after several reuses.Se estudió la actividad fotocatalítica y estabilidad de materiales 3% Fe/TiO2 sintetizados por impregnación húmeda incipiente (3% Fe/TiO2-DP25) y sol-gel (3% Fe/TiO2-sol-gel), usando fenol como molécula modelo. Se evaluó el efecto de parámetros de operación como concentración de fotocatalizador, H2O2 y pH de la solución. Los mayores porcentajes de degradación de fenol con ambos materiales se lograron utilizando 26 mg de fotocatalizador y 600 Mg/Ll de H2O2 a un pH de 3.0. El mejor porcentaje de degradación de fenol (99%) se obtuvo usando el catalizador 3% Fe/TiO2-DP25, en comparación a un 70% con el material 3% Fe/TiO2-sol-gel. No obstante, el material preparado por impregnación húmeda incipiente fue inestable evidenciando lixiviación de hierro. Por lo tantio, este catalizador no es adecuado para la degradación de fenol debido a razones ambientales y económicas. El catalizador preparado por sol-gel no mostró lixiviación de hierro durante la reacción y mantuvo su actividad y estabilidad catalítica después de varios reúsos