Relating black holes in two and three dimensions

The three dimensional black hole solutions of Ba\~nados, Teitelboim and Zanelli (BTZ) are dimensionally reduced in various different ways. Solutions are obtained to the Jackiw-Teitelboim theory of two dimensional gravity for spinless BTZ black holes, and to a simple extension with a non-zero dilaton potential for black holes of fixed spin. Similar reductions are given for charged black holes. The resulting two dimensional solutions are themselves black holes, and are appropriate for investigating exact ``S-wave'' scattering in the BTZ metrics. Using a different dimensional reduction to the string inspired model of two dimensional gravity, the BTZ solutions are related to the familiar two dimensional black hole and the linear dilaton vacuum.Comment: 12 pages, CTP #2181, January 199

Latitudinal variation of foF2 hysteresis of solar cycles 20, 21 and 22 and its application to the analysis of long-term trends

F2 monthly median values for equinoctial months of solar cycles 20, 21 and 22, were analyzed for 37 worldwide stations. For each solar cycle and for a given , the difference between F2 in the falling branch of the cycle and the corresponding value of the rising branch is evaluated. The maximum difference, considered as the hysteresis magnitude, varies systematically with geomagnetic latitude. The pattern is similar for every cycle, with greater hysteresis magnitudes for stronger solar cycles. It is positive between 45S and 45N, with minimum values at equatorial latitudes and maximum at around 25-30 on either side of the equator. For latitudes greater than 50 negative values are observed. At around 25?30 and at high latitudes the hysteresis magnitude reaches 2MHz for solar cycle with high activity levels, which represents around 20% of F2. The effects of F2 hysteresis on the analysis of long-term data sequences is analyzed. In the case of long-term trend analysis, the hysteresis behavior may induce spurious trends as a consequence of the filtering processes applied to F2 time series previous to trend values estimation. This problem may be solved by considering time series covering several solar cycles. F2 monthly median values for equinoctial months of solar cycles 20, 21 and 22, were analyzed for 37 worldwide stations. For each solar cycle and for a given Rz, the difference between F2 in the falling branch of the cycle and the corresponding value of the rising branch is evaluated. The maximum difference, considered as the hysteresis magnitude, varies systematically with geomagnetic latitude. The pattern is similar for every cycle, with greater hysteresis magnitudes for stronger solar cycles. It is positive between 45S and 45N, with minimum values at equatorial latitudes and maximum at around 25?30 on either side of the equator. For latitudes greater than 50 negative values are observed. At around 25?30 and at high latitudes the hysteresis magnitude reaches 2MHz for solar cycle with high activity levels, which represents around 20% of F2. The effects of F2 hysteresis on the analysis of long-term data sequences is analyzed. In the case of long-term trend analysis, the hysteresis behavior may induce spurious trends as a consequence of the filtering processes applied to F2 time series previous to trend values estimation. This problem may be solved by considering time series covering several solar cycles.Fil: Ortiz de Adler, Nieves del Carmen. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; ArgentinaFil: Elias, Ana Georgina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentin

Aspects of the pseudo Chiral Magnetic Effect in 2D Weyl-Dirac Matter

A connection is established between the continuum limit of the low-energy tight-binding description of graphene immersed in an in-plane magnetic field and the Chiral Magnetic Effect in Quantum Chromodynamics. A combination of mass gaps that explicitly breaks the equivalence of the Dirac cones, favoring an imbalance of pseudo-chiralities, is the essential ingredient to generate a non-dissipative electric current along the external field. Currents, number densities and condensates generated from this setup are investigated for different hierarchies of the energy scales involved.Comment: 12 pages, 8 figures. Several text improvements. Accepted for publication in European Physical Journal

Factores relacionados con la Psicosis Refractaria.

El propósito del estudio fue determinar la prevalencia y las variables relacionadas con la Psicosis Refractaria al Tratamiento (TRP) en una muestra de pacientes con trastornos psicóticos diagnosticados a través de una primera hospitalización psiquiátrica en el Hospital Clínico Universitario de Valladolid (HCUV) entre los años 2004 y 2011. Métodos: Es un estudio observacional retrospectivo, en el que la información se obtuvo a través de los informes de alta hospitalaria del primer episodio de psicosis (FEP) de una muestra de 44 pacientes. Después de al menos 5 años de seguimiento, estos pacientes fueron reevaluados y divididos en dos grupos: TRP y no TRP. Usamos un cuestionario que contestaron los profesionales de Salud Mental a cargo de los pacientes. Realizamos un análisis estadístico bivariante para establecer la asociación entre distintas variables sociodemográficas y clínicas y la evolución de la psicosis. Resultados: Un total de 14 personas (31,8% de la muestra) cumplieron criterios para TRP. El sexo, la edad de comienzo, el uso de sustancias, las características del primer ingreso, la historia familiar de enfermedades mentales o el nivel de funcionamiento premórbido no mostraron diferencias estadísticas entre los dos grupos. La puntuación total en la Escala de Síntomas Positivos y Negativos (PANSS) en el primer episodio de psicosis, la puntuación en la escala de Funcionamiento Personal y Social (PSP) tras ≥5 años de seguimiento, y una mala adherencia al tratamiento antipsicótico mostraron una relación significativa con la presencia de TRP. Conclusión: Es un reto para clínicos e investigadores comprender los mecanismos que subyacen tras la mala evolución de los trastornos psicóticos, y desarrollar intervenciones precoces que permitan prevenir la TRP, o al menos mejorar la sintomatología y fomentar un buen funcionamiento personal y social en estos pacientes. La utilización de clozapina y antipsicóticos inyectables de acción prolongada podrían ser útiles en el tratamiento de la TRP.Grado en Medicin

Interaction and TIC in the University Teaching

Este artículo, además de tratar la necesidad del uso de las «TICs» tecnologías de la informa- ción y la comunicación en la docencia universitaria, relata la experiencia del uso de la plataforma Ilias en la Universidad de Jaén, la fundamentación del modelo didáctico que la sustenta, así como el análisis de la interacción educativa en situación de enseñanza/apren- dizaje a través de las nuevas herramientas. Por último se plantea el estado de la cuestión en el uso de las TIC, tanto como apoyo a la docencia presencial como semipresencial o a distancia.This article deals with the need of using «ICT» information and communication tecnologies at universitary teaching levels. It reports on an experience consisting in the application of the so called Ilias platform developed at the University of Jaén. It reflects the theoretical didactic model on which it is supported, and the need to enhance teacher training in order to be used. A state-of-the-art is also presented as regards its use both presential or semi- presential teaching

La formación básica de personas adultas en Andalucía desde la perspectiva del profesorado

Este artículo se estructura en tres grandes apartados, el primero, estudia la justificación y diseño de la investigación, la fundamentación teórica de la enseñanza de adultos, como base del intercambio social; el diseño y desarrollo del currículum para personas adultas, como proyecto de formación con las personas adultas, así como el desarrollo y secuenciación de la UDI-G del profesor Medina (1992), (Medina y Domínguez, 1995); y la estructura organizativa de la Educación de Adultos en Andalucía; el segundo apartado hace referencia a la metodología de la investigación, en el cual, presentamos el diseño metodológico de la misma, haciendo un planteamiento plurimetódico; por un lado, la metodología descriptiva a través del método de encuesta y el método etnográfico a partir del estudio de casos, por otro; en el tercer apartado, se plantean los resultados obtenidos, así como, las conclusiones e implicaciones de la investigación.This article consits of three main sections, the first one, studies the justification and design of the investigation, the theoretical foundations of adults education, as the basis of the social interchange; the design and development of the curriculum for adult people, as project of formation with the adult persons, as well as the development and sequence of integrated-globalised-didactic-unit (UDI-G) by professor Medina (1992), (Medina and Domínguez, 1995); and the organizational structure of Adults education in Andalusia; the second section refers to the methodology of the investigation, in which we present the methodological design of it one, carrying out a plurimethodic aproach; on the one hand, the descriptive methodology by means of the method of survey and the ethnographic method from the study of cases on the other hand; in the third section, we present the results, as well as the conclusions and implications of the investigation

Design and validation of a questionnaire to measure research skills: experience with engineering students

Universities in Latin American countries are undergoing major changes in its institutional and academic settings. One strategy for continuous improvement of teaching and learning process is the incorporation of methods and teaching aids seeking to develop scientific research skills in students from their undergraduate studies. The aim of this study is the validation of a questionnaire to measure research skills with engineering students. Questionnaire validation was performed by: literature review, semantic and content validation by experts from three Latin American universities, finishing with a factorial and reliability validation. The instrument was applied to 150 students (75,3% men and 24,7% women) that were enrolled in the basic level of engineering. The validated questionnaire has 20 items. The correlations between factors of the instrument, show relationship and dependence between them, indicating the validity of the questionnaire. The reliability of the instrument was calculated using Cronbach's alpha coefficient, which reached a value of .91 in the total scale. The statistical results to validate the questionnaire have been significant, allowing us to propose this experience as a starting point to implement further studies about the development of research skills in university’s students from other areas of knowledgePeer Reviewe

The Future of Plastics Trade: Identifying Determinants and Impacts of the Shifting Global Plastic Scraps Network

Plastic waste management is an area of increasing concern for environmental and public health. Existing research shows that as of 2019, 79% of total generated plastic waste has accumulated in landfills or leaked into the environment, 12% incinerated, and 9% recycled. China’s Operation National Sword, launched in 2017, banned the import of plastic waste and other materials, triggering ripple effects throughout the global plastic scraps trade network. The impacts are cross-sectoral and multi-scalar, cascading across markets, policy, the natural environment, public health, and have increased uncertainty about the future of the global trade of plastics. To understand shifts across the global plastic scraps network, the author of this dissertation first uses a Social Network Analysis (SNA) approach to explore the structural changes over time of the plastic trade network, especially due to China’s Operation National Sword. Results show that Southeast Asian, and Western and Central European countries became the most important traders of plastic waste after China’s Operation National Sword. A cross-sectional time-series multi-method analysis additionally shows that poorer countries with large manufacturing sectors were the most affected by the policy, becoming havens for plastic waste. Trade partners of top plastic traders such as China became more likely to import waste as well. Results from a System Generalized Method of Moments (SGMM) analysis reveals that wealthier countries trade more plastic scraps of mixed materials, while large manufacturers import more polyethylene plastic. Countries with higher environmental performance were better to prevent plastic import increases relative to their exports

Motivating Students with Learning Disabilities to Succeed in Education

Many students with learning disabilities may feel incapable of achieving in their academic goals and are in need of greater motivation. They may believe that abilities are innate and fixed and that their ability to learn and achieve is unchangeable. However, they may not be aware of growth mindset strategies that can support their academic success. To address the need for motivation, I created three lessons to teach seventh grade students in a resource classroom at Aptos Jr. High strategies for a growth mindset and to stay motivated throughout their academic challenges