6,311 research outputs found

    μSQUID susceptometry of molecular qubits

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    El objetivo fundamental de este trabajo es la investigación de las propiedades magnéticas de distintos tipos de partículas pertenecientes a dos mundos: el mundo cuántico, representado por una nueva familia de imanes moleculares, y el mundo clásico, representado por una serie de nanopartículas magnéticas sintetizadas en ferritina. Estos estudios han sido realizados por medio de medidas de susceptibilidad magnética ac a muy bajas temperaturas, utilizando para ello susceptómetros uSQUID enormemente sensibles desarrollados también como parte de este trabajo

    Quantum electrodynamics with magnetic textures

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    Coherent exchange between photons and different matter excitations (like qubits, acoustic surface waves or spins) allows for the entanglement of light and matter and provides a toolbox for performing fundamental quantum physics. On top of that, coherent exchange is a basic ingredient in the majority of quantum information processors. In this work, we develop the theory for coupling between magnetic textures (vortices and skyrmions) stabilized in ferromagnetic nanodiscs and microwave photons generated in a superconducting circuit. Within this theory we show that this hybrid system serves for performing broadband spectroscopy of the magnetic textures. We also discuss the possibility of reaching the strong coupling regime between these texture excitations and a single photon residing in a microwave superconducting cavity

    Improving scope sensitivity in contingent valuation: joint and separate evaluation of health states

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    We present data of a contingent valuation survey, testing the effect of evaluation mode on the monetary valuation of preventing road accidents. Half of the interviewees was asked to state their willingness to pay (WTP) to reduce the risk of having only 1 type of injury (separate evaluation, SE), and the other half of the sample was asked to state their WTP for 4 types of injuries evaluated simultaneously (joint evaluation, JE). In the SE group, we observed lack of sensitivity to scope while in the JE group WTP increased with the severity of the injury prevented. However, WTP values in this group were subject to context effects. Our results suggest that the traditional explanation of the disparity between SE and JE, namely, the so-called “evaluability,” does not apply here. The paper presents new explanations based on the role of preference imprecision

    A normal metal tunnel-junction heat diode

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    We propose a low-temperature thermal rectifier consisting of a chain of three tunnel-coupled normal metal electrodes. We show that a large heat rectification is achievable if the thermal symmetry of the structure is broken and the central island can release energy to the phonon bath. The performance of the device is theoretically analyzed and, under the appropriate conditions, temperature differences up to \sim 200 mK between the forward and reverse thermal bias configurations are obtained below 1 K, corresponding to a rectification ratio R\mathcal{R} \sim 2000. The simplicity intrinsic to its design joined with the insensitivity to magnetic fields make our device potentially attractive as a fundamental building block in solid-state thermal nanocircuits and in general-purpose cryogenic electronic applications requiring energy management.Comment: 4.5 pages, 4 color figure

    Hacia una nueva percepción social de las personas con discapacidades : legislación, medicina y los inválidos del trabajo en España (1900-1936)

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    Este trabajo pretende analizar el papel que tuvo la medicina, dentro del clima de reforma social de la España del primer tercio del siglo XX, como factor que contribuyó a dar forma a las discapacidades. Situándonos en la perspectiva desarrollada en el marco de los nuevos estudios sociales sobre la discapacidad, y utilizando como fuentes fundamentales las revistas científico-profesionales y la documentación de las Cámaras legislativas, examinamos la legislación destinada a regular la protección frente a los accidentes del trabajo y las instituciones creadas para atender a las personas con deficiencias físicas y/o funcionales derivadas de ellos. Buscamos así examinar la influencia de esas contribuciones sobre la transformación de la percepción social acerca de las personas con discapacidades

    Relación entre el proceso histórico: Tartessos/ colonización fenicia y la alta Andalucía

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    [email protected] fenicios y tartesiosfueron losfundamentales transmisores de la cultura semita hacía el hinterland, concretamente hacia la alta Andalucía. la antigua Oretania, rica en minas. Allí se han hallado huellas abundantes de la impronta orientalizante que imprimen un lluevo carácter al ambiente materiaL e incluso espiritual nativo. Ella lo apreciamos en numerosos rasgas en los múltiples yacimientos de esta región. Ile ahí el ejemplo de Puente Tablas, y más intensamente aún el de Cástulo. Concretamente en su santuario de la Muela, de la edadfinal del Bronce, hallamos huellasfehacientes de préstamos materiales y espiritualesfenicios, que desarrollarnos en antplftud. En otros puntas del yacimiento tan,b¡éít se iran recuperado tiraferiales suntuarios para documentar la colonización fenicio/tartésica: en ajuares de enterramientos, datados en época oretana: en estratos noji~nerarios. con cronologia alta . aunque dentro del ámbito de necrópolis del siglo IV a. C. (Los Palos. Estacar de I?obarinas,i. en el poblado de la tinelo al que pertenece el edificio sagrado al que aludimos más arriba

    New Burnout Evaluation Model Based on the Brief Burnout Questionnaire: Psychometric Properties for Nursing

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    Health care personnel are considered one of the worker sectors most exposed to heavier workloads and work stress. One of the consequences associated with the exposure to chronic stress is the development of burnout syndrome. Given that evaluating this syndrome requires addressing the context in which they are to be used, the purpose of this work was to analyze the psychometric properties and structure of the Burnout Brief Questionnaire (CBB), and to propose a more suitable version for its application to health professionals, and more specifically nurses. The final study sample was made up of 1236 working nursing professionals. An exploratory factorial analysis was carried out and a new model was proposed through a confirmatory factorial analysis. Thus, validation of the CBB questionnaire for nursing health care personnel showed an adequate discrimination of the items and a high internal consistency of the scale. With respect to the factorial analysis, four factors were extracted from the revised model. Specifically, these new factors, called job dissatisfaction, social climate, personal impact, and motivational abandonment, showed an adequate index of adjustment. Thus, the Brief Burnout Questionnaire Revised for nursing staff has favorable psychometric properties, and this model can be applied to all health care professionals

    Determinación de antioxidantes mediante microextracción liquida dispersiva y cromatografía de líquidos: optimización del método de extracción

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    Un antioxidante es una molécula capaz de retardar o prevenir la oxidación de otras moléculas. La oxidación es una reacción química de transferencia de electrones de una sustancia a un agente oxidante. Las reacciones de oxidación pueden producir radicales libres que comienzan reacciones en cadena que dañan las células. Los antioxidantes terminan estas reacciones quitando intermedios del radical libre e inhiben otras reacciones de oxidación oxidándose ellos mismos. Debido a esto es que los antioxidantes son a menudo agentes reductores tales como tioles o polifenoles. Los antioxidantes se encuentran contenidos en el olivo, ajo, arroz integral, café, coliflor, brócoli, jengibre, perejil, cebolla, cítricos, tomates, aceite de semilla de la vid, té, romero, entre otras muchas sustancias. Las catequinas pertenecen a la familia de los polifenoles y se encuentran en el café, té, cacao entre otros alimentos. Sin embargo, el tratamiento térmico al que se someten estos alimentos hace que la capacidad antioxidante de los mismos se vea afectada. Las técnicas de microextracción líquido-líquido son una miniaturización de la técnica clásica de extracción líquido-líquido, eliminando las desventajas que ésta última presenta (e.g., elevados volúmenes de disolventes orgánicos y la elevada manipulación de la muestra). Las numerosas ventajas que las técnicas de microextración presentan son: Rapidez, bajo coste, elevados factores de enriquecimiento, bajo consumo de muestra y reactivos, buena repetibilidad y sensibilidad, entre otras. Por ello, se pretende desarrollar un método en el que se emplee una técnica de microextracción líquido-líquido para determinar catequinas en bebidas de origen vegetal (e.g., té y café) con el objetivo de estudiar la estabilidad de éstos antioxidantes durante el procesado

    Analysis of the Risk and Protective Roles of Work-Related and Individual Variables in Burnout Syndrome in Nurses

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    Aims: Burnout syndrome is a phenomenon that is becoming ever more widespread, especially in workers such as nurses who have heavy workloads and time pressures. The progression of burnout syndrome has been shown to be related to both individual and work-related variables. The objective of this study is to examine the risk and protective roles played by work-related and personal variables, both sociodemographic and psychological, in the development of burnout in nurses. Method: The sample was composed of 1236 nurses aged between 21 and 57 years, with a mean age of 31.50 years (SD = 6.18). Women accounted for 84.5% (n = 1044), and the remaining 15.5% (n = 192) were men. Exploratory tests were performed to understand the relationships between burnout and other variables, and a binary logistic regression was conducted to understand the roles of these variables in the incidence of this syndrome. Lastly, a regression tree was constructed. Results: The results show that the sociodemographic variables examined are not related to the level of burnout in nurses. However, certain work-related variables, such as spending more time with colleagues and patients and reporting good-quality relationships, exhibit a negative relationship with the occurrence of burnout. Of the psychological variables, the stress factors conflict-social acceptance and irritability-tension-fatigue, as well as informative communication, are shown to be risk factors for the appearance of burnout in nurses. In contrast, the communication skills factor, empathy, and energy-joy exert a protective function. Conclusion: Identifying the variables that influence the occurrence of burnout syndrome and understanding the manner in which they exert their influence are key elements in the development of effective prevention and intervention of burnout in nursing
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