131 research outputs found

    Huge linear magnetoresistance due to open orbits in γ\gamma-PtBi2_2

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    Some single-crystalline materials present an electrical resistivity which decreases between room temperature and low temperatures at zero magnetic field as in a good metal and switches to a nearly semiconductinglike behavior at low temperatures with the application of a magnetic field. Often, this is accompanied by a huge and nonsaturating linear magnetoresistance which remains difficult to explain. Here we present a systematic study of the magnetoresistance in single-crystal γ\gamma-PtBi2_2. We observe that the angle between the magnetic field and the crystalline cc axis fundamentally changes the magnetoresistance, going from a saturating to a nonsaturating magnetic field dependence. In between, there is one specific angle where the magnetoresistance is perfectly linear with the magnetic field. We show that the linear dependence of the nonsaturating magnetoresistance is due to the formation of open orbits in the Fermi surface of γ\gamma-PtBi2_2.Comment: 12 pages, 8 figures including Supplementary Materia

    Orden y desorden en superconductividad

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    Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de la Materia Condensada. Fecha de lectura: 19-06-0

    Analysis of Four Polymorphisms Located at the Promoter of the Estrogen Receptor Alpha ESR1 Gene in a Population With Gender Incongruence

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    [Abstract] Introduction: Gender incongruence defines a state in which individuals feel discrepancy between the sex assigned at birth and their gender. Some of these people make a social transition from male to female (transwomen) or from female to male (trans men). By contrast, the word cisgender describes a person whose gender identity is consistent with their sex assigned at birth. Aim: To analyze the implication of the estrogen receptor a gene (ESR1) in the genetic basis of gender incongruence. Main Outcome Measures: Polymorphisms rs9478245, rs3138774, rs2234693, rs9340799. Method: We carried out the analysis of 4 polymorphisms located at the promoter of the ESR1 gene (C1 ¼ rs9478245, C2 ¼ rs3138774, C3 ¼ rs2234693, and C4 ¼ rs9340799) in a population of 273 trans women, 226 trans men, and 537 cis gender controls. For SNP polymorphisms, the allele and genotype frequencies were analyzed by c2 test. The strength of the SNP associations with gender incongruence was measured by binary logistic regression. For the STR polymorphism, the mean number of repeats were analyzed by the ManneWhitney U test. Measurement of linkage disequilibrium and haplotype frequencies were also performed. Results: The C2 median repeats were shorter in the trans men population. Genotypes S/S and S/L for the C2 polymorphism were overrepresented in the trans men group (P ¼ .012 and P ¼ .003 respectively). We also found overtransmission of the A/A genotype (C4) in the trans men population (P ¼ .017), while the A/G genotype (C4) was subrepresented (P ¼ .009]. The analyzed polymorphisms were in linkage disequilibrium. In the trans men population, the T(C1)-L(C2)-C(C3)-A(C4) haplotype was overrepresented (P ¼ .019) while the T(C1)-L(C2)-C(C3)-G(C4) was subrepresented (P ¼ .005). Conclusion: The ESR1 is associated with gender incongruence in the trans men populationThis work was supported by grants: ED431B 019/02 (EP), PGC2018-094919-B-C21 (AG), PGC2018-094919-B-C22 (RF), and FPU 15/02558 (JCC)Xunta de Galicia; ED431B 019/0

    Low-Frequency Imaginary Impedance at the Superconducting Transition of 2H-NbSe2

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    The superconducting transition leads to a sharp resistance drop in a temperature interval that can be a small fraction of the critical temperature Tc. A superconductor exactly at Tc is thus very sensitive to all kinds of thermal perturbation, including the heat dissipated by the measurement current. We show that the interaction between electrical and thermal currents leads to a sizable imaginary impedance at frequencies of the order of tens of hertz at the resistive transition of single crystals of the layered material 2H-NbSe2.We explain the result using models developed for transition-edge sensors. By measuring under magnetic fields and at high currents, we find that the imaginary impedance is strongly influenced by the heat associated with vortex motion and out-of-equilibrium quasiparticles

    Convivencia, conflictos y mediación escolar en educación secundaria: estudio de caso

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    Educational work occurs in a context where interpersonal relationships intervene, which are not exempt from school conflicts. Inappropriate management can trigger a series of discrepancies and adverse reactions, giving rise to aggressions, insults, etc., to the detriment of the school coexistence of Compulsory Secondary Education (ESO) centers, which can lead to school violence. The objectives of the were to evaluate the students' perception of the conflict; the types of conflicts and the mechanisms to resolve them. The participants were 147 students from a Secondary Education Institute (IES) enrolled in 3rd and 4th of ESO and 3rd of the Performance and Learning Improvement Program (PMAR) and 4th of the Curricular Diversification Program ( PDC), between 13 and 18 years old. The instrument was a questionnaire on causes and types of conflicts, elaborated from Ortuño (2014) with the aim of evaluating the students' perception of the conflict; the most common types of conflicts that occur between them and the mechanisms they use to resolve them. The results indicate that the conflicts that occur the most are due to the occupation of the playgrounds; The changes of desks and insulting the classmates and the less frequent ones are insulting the teacher and the destruction of materials. The conclusions highlight the importance of knowing the conflicts that occur daily for proper management without resulting in violence or bullying. As future lines of research, prevention and resolution of school conflicts are highlighted.La labor educativa ocurre en un contexto donde intervienen relaciones interpersonales, que no quedan exentas de conflictos escolares. Una gestión inadecuada puede desencadenar una serie de discrepancias y reacciones adversas, dando lugar a agresiones, insultos, etc., en perjuicio de la convivencia escolar de los centros de Enseñanza Secundaria Obligatoria (ESO), pudiendo derivar en violencia escolar. Los objetivos del  fueron evaluar la percepción de los estudiantes ante el conflicto; los tipos de conflictos  y los mecanismos  para resolverlos. Los participantes fueron 147 estudiantes de un Instituto de Enseñanza Secundaria (IES) Escolarizados en 3.º y 4.º de ESO y 3.º del Programa de Mejora del Rendimiento y Aprendizaje (PMAR) y 4.º del Programa de Diversificación Curricular (PDC), entre 13 y 18 años. El instrumento fue un cuestionario sobre causas y tipos de conflictos, elaborado a partir de Ortuño (2014) con el objetivo de evaluar la percepción de los estudiantes ante el conflicto; los tipos de conflictos más habituales que se producen entre ellos y los mecanismos que utilizan para resolverlos. Los resultados apuntan que los conflictos que más se producen son debidos a la ocupación de las pistas del recreo; los cambios de pupitre e insultar a los compañeros y los menos frecuentes son insultar al profesor y el destrozo de materiales. Las conclusiones destacan la importancia de conocer los conflictos que se producen diariamente para una adecuada gestión sin que deriven en violencia o acoso escolar. Como futuras líneas de investigación se subraya medidas de prevención y solución de conflictos escolares

    Reducing Emissions in the Maritime Sector: Offshore Wind Energy as a Key Factor

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    The maritime environment is the setting for a variety of economic activities, such as offshore wind energy, aquaculture, salt extraction, and oil and gas platforms. While some of these activities have a long-term presence, others require decarbonization as they head towards their demise. In this context, the aim of this study is to develop a methodology to replace the electrical energy from offshore high-emission industrial processes with clean electricity generated by offshore wind energy. The proposal is structured in three phases: initiation, which involves the collection of quantitative, technical, and geospatial information of the study area; indicators, where the main indicators are calculated, and the best alternative is selected using multi-criteria evaluation methods; and finally, short-, medium-, and long-term scenarios are proposed. The methodology is evaluated in Spain, and the best alternative, which has a nominal power of 225 MW, is capable of avoiding up to 1.44 MtCO2 by 20502024-2

    Linear nonsaturating magnetoresistance in the Nowotny chimney ladder compound Ru2Sn3

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    We present magnetoresistivity measurements in high-quality single crystals of the Nowotny chimney ladder compound Ru2Sn3. We find a linear and nonsaturating magnetoresistance up to 20 T. The magnetoresistance changes with the magnetic field orientation at small magnetic fields, from a positive to a negative curvature. Above 5 T, the magnetoresistance shows no sign of saturation up to 20 T for any measured angle. The shape of the anisotropy in the magnetoresistance remains when increasing temperature and Kohler's rule is obeyed. We associate the linear and nonsaturating magnetoresistance to a small Fermi surface with hot spots, possibly formed as a consequence of the structural transition. We discuss the relevance of electron-electron interactions under magnetic fields and aspects of the topologically nontrivial properties expected in Ru2Sn3This work was supported by the Spanish Research State Agency (FIS2017-84330-R, CEX2018-000805-M, RYC2014-15093, MAT2017-87134-C2-2-R), by the Comunidad de Madrid through the program NANOMAGCOST-CM (Grant No. S2018/NMT-4321) and by the European Research Council PNICTEYES project through Grant Agreement No 67908

    SMART: Selection Model for Assessment Resources and Techniques

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    The European Higher Education Area has ushered in a significant shift in university teaching, aiming to engage students more actively in classes. Professors have leveraged virtual platforms and external tools to introduce interactive tasks. With the proliferation of technology, educators face a challenge in choosing the most suitable approach. This paper presents SMART (Selection Model for Assessment Resources and Techniques), a methodology that determines the optimal assessment activities for university-level education. The methodology employs multicriteria decision-making techniques, specifically AHP and TOPSIS methods, to optimize activities based on various subject-, lecturer-, activity-, and student-related criteria. According to SMART, the top five assessment tasks are group and individual report submissions, workshops, complex H5P activities, and questionnaires. Therefore, it is advisable to prioritize these activities based on the methodology’s results, emphasizing their importance over other assessment methods.2023-2

    Factores que influyen en el proceso de búsqueda de identidad en la adolescencia adoptiva

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    La adolescencia es un periodo caracterizado por los cambios que llevan a adentrarse en el mundo de la adultez. Una de las principales tareas que los adolescentes deben realizar es encontrar y definir la propia identidad, como un ser único y diferenciado del resto. Cuando el adolescente ha sido adoptado, a dicha construcción de la identidad se le suman más factores de los habituales. En este trabajo se analiza el proceso de búsqueda de identidad en la adolescencia adoptiva a través de los factores de riesgo y protección asociados: perfil de las familias que desean adoptar, estilos educativos, estilo de apego, conocimiento de la condición de adoptado, comunicación de la adopción, búsqueda de los orígenes, vida previa del menor, edad de la adopción y escolarización. Debido al incremento en la actualidad de relaciones problemáticas entre menores adoptados y sus familias adoptivas, en este trabajo se incluye un apartado en el que se tratan las conductas disruptivas de estos menores y un breve análisis sobre la intervención realizada en el ámbito de la adopción

    Coexistence, school conflicts and school mediation in secondary education: a case study

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    ©2022. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Published, version of a Published Work that appeared in final form in Azarbe. Revista Internacional de Trabajo social y bienestar. To access the final edited and published work see https://doi.org/10.6018/azarbe.505931La labor educativa ocurre en un contexto donde intervienen relaciones interpersonales, que no quedan exentas de conflictos escolares. Una gestión inadecuada puede desencadenar una serie de discrepancias y reacciones adversas, dando lugar a agresiones, etc., en perjuicio de la convivencia escolar de los centros de Enseñanza Secundaria Obligatoria (ESO), pudiendo derivar en violencia escolar. Los objetivos del estudio fueron evaluar la percepción de los estudiantes ante el conflicto; los tipos de conflictos y los mecanismos para resolverlos. Los participantes fueron 147 estudiantes de un Instituto de Enseñanza Secundaria (IES) Escolarizados en 3.º y 4.º de ESO y 3.º del Programa de Mejora del Aprendizaje y Rendimiento (PMAR) y 4.º del Programa de Diversificación Curricular (PDC), entre 13 y 18 años. El instrumento fue un cuestionario sobre causas y tipos de conflictos, elaborado a partir de Ortuño (2014) con el objetivo de evaluar la percepción de los estudiantes ante el conflicto; los tipos de conflictos más habituales que se producen entre ellos y los mecanismos que utilizan para resolverlos. Los resultados apuntan que los conflictos que más se producen son debidos a la ocupación de las pistas del recreo; los cambios de pupitre e insultar a los compañeros y los menos frecuentes son insultar al profesor y el destrozo de materiales. Las conclusiones destacan la importancia de conocer los conflictos que se producen diariamente, para una adecuada gestión sin que deriven en violencia o acoso escolar. Como futuras líneas de investigación se subraya medidas de prevención y solución de conflictos escolares.--------------------------------Educational work occurs in a context where interpersonal relationships intervene, which are not exempt from school conflicts. Inappropriate management can trigger a series of discrepancies and adverse reactions, giving rise to aggressions, etc., to the detriment of the school coexistence of Compulsory Secondary Education (ESO) centers, which can lead to school violence. The objectives of the were to evaluate the students’ perception of the conflict; the types of conflicts and the mechanisms to resolve them. The participants were 147 students from a Secondary Education Institute (IES) enrolled in 3rd and 4th of ESO and 3rd of the Performance and Learning Improvement Program (PMAR) and 4th of the Curricular Diversification Program (PDC), between 13 and 18 years old. The instrument was a questionnaire on causes and types of conflicts, elaborated from Ortuño (2014) with the aim of evaluating the students’ perception of the conflict; the most common types of conflicts that occur between them and the mechanisms they use to resolve them. The results indicate that the conflicts that occur the most are due to the occupation of the playgrounds; The changes of desks and insulting the classmates and the less frequent ones are insulting the teacher and the destruction of materials. The conclusions highlight the importance of knowing the conflicts that occur daily for proper management without resulting in violence or bullying. As future lines of research, prevention and resolution of school conflicts are highlighted
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