141 research outputs found

    Variability estimation in resistive switching devices, a numerical and kinetic Monte Carlo perspective

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    Acknowledgments The authors thank the support of the Spanish Ministry of Science, Innovation and Universities and the FEDER program through projects TEC2017-84321-C4-1-R, TEC2017-84321-C4-3-R, and projects A.TIC.117.UGR18, IE2017-5414 and B.TIC.624.UGR20 funded by the Consejería de Conocimiento, Investigación y Universidad, Junta de Andalucía (Spain) and the FEDER program. Funding for open access charge: Universidad de Granada/CBUAWe have analyzed variability in resistive memories (Resistive Random Access Memories, RRAMs) making use of advanced numerical techniques to process experimental measurements and simulations based on the kinetic Monte Carlo technique. The devices employed in the study were fabricated using the TiN/Ti/HfO2/W stack. The switching parameters were obtained making use of new developed extraction methods. The appropriateness of the advanced parameter extraction methodologies has been checked by comparison to kinetic Monte Carlo simulations; in particular, the reset and set events have been studied and detected. The data obtained were employed to shed light on the resistive switching operation and the cycle-to-cycle variability. It has been shown that variability depends on the numerical technique employed to obtain the set and reset voltages, therefore, this issue must be taken into consideration in RS characterization and modeling studies. The proposed techniques are complementary and depending on the technology and the curves shape the features of a particular method could make it to be the most appropriate.Spanish Ministry of Science, Innovation and Universities and the FEDER program through projects TEC2017-84321-C4-1-R, TEC2017-84321-C4-3-RConsejería de Conocimiento, Investigación y Universidad, Junta de Andalucía (Spain) and the FEDER program, projects A.TIC.117.UGR18, IE2017-5414 and B.TIC.624.UGR20Funding for open access charge: Universidad de Granada/CBU

    Multivariate analysis and extraction of parameters in resistive RAMs using the Quantum Point Contact model

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    A multivariate analysis of the parameters that characterize the reset process in RRAMs has been performed. The different correlations obtained can help to shed light on the current components that contribute in the Low Resistance State (LRS) of the technology considered. In addition, a screening method for the Quantum Point Contact (QPC) current component is presented. For this purpose the second derivative of the current has been obtained using a novel numerical method which allows determining the QPC model parameters. Once the procedure is completed, a whole RS series of thousands of curves is studied by means of a genetic algorithm. The extracted QPC parameter distributions are characterized in depth to get information about the filamentary pathways associated with LRS in the low voltage conduction regime.Spanish Ministry of Economy and Competitiveness TEC2014-52152-C3-2-R , MTM2013-47929-P (also supported by the FEDER program)IMB-CNM Spanish Ministry of Economy and Competitiveness TEC2014-52152-C3-1-R and TEC2014-54906-JIN (supported by the FEDER program)ENIAC Joint Undertaking-PANACHE project.Spanish ICTS Network MICRONANOFAB

    Displays and Photonics Application Group activities

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    Displays and Photonics Application Group (GDAF) is devoted to design and development of passive and active devices and sensors for their applications in WDM networks, CWDM, POP, and RF over fiber networks using different technologies such as optical fibers, liquid crystals, and integrated optics. The group is also very active in modeling, electrooptical characterization, and addressing electronics of LCDs. In this article we are going to describe the main activities carried out in the group.Publicad

    Transplantation of mesenchymal stem cells exerts a greater long-term effect than bone marrow mononuclear cells in a chronic myocardial infarction model in rat

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    The aim of this study is to assess the long-term effect of mesenchymal stem cells (MSC) transplantation in a rat model of chronic myocardial infarction (MI) in comparison with the effect of bone marrow mononuclear cells (BM-MNC) transplant. Five weeks after induction of MI, rats were allocated to receive intramyocardial injection of 106 GFP-expressing cells (BM-MNC or MSC) or medium as control. Heart function (echocardiography and 18F-FDG-microPET) and histological studies were performed 3 months after transplantation and cell fate was analyzed along the experiment (1 and 2 weeks and 1 and 3 months). The main findings of this study were that both BM-derived populations, BM-MNC and MSC, induced a long-lasting (3 months) improvement in LVEF (BM-MNC: 26.61 ± 2.01% to 46.61 ± 3.7%, p < 0.05; MSC: 27.5 ± 1.28% to 38.8 ± 3.2%, p < 0.05) but remarkably, only MSC improved tissue metabolism quantified by 18FFDG uptake (71.15 ± 1.27 to 76.31 ± 1.11, p < 0.01), which was thereby associated with a smaller infarct size and scar collagen content and also with a higher revascularization degree. Altogether, results show that MSC provides a long-term superior benefit than whole BM-MNC transplantation in a rat model of chronic MI

    The karst site of Las Palomas (Guadalteba County, Málaga, Spain): A preliminary study of its MiddleeLate Pleistocene archaeopaleontological record

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    Cleaning works in the cave of Las Palomas in Teba (Málaga, Spain), developed by the Guadalteba Consortium, have provided a number of lithic tools and knapping products that may be ascribed to the Mode III technotypological tradition as well as remains of a number of large mammal species typical of MiddleeLate Pleistocene times. Topographic measurements help to place this ancient cave within a karst landform. This discovery opens up new perspectives in the research on the Neanderthal groups that inhabited the valleys of Guadalteba and Turón rivers in the middle basin of the Guadalhorce River, and thus in the southern region of the Iberian Peninsula

    Promoción de la huerta orgánica y de alimentación saludable en niños de la EEP Nº7 de Puerto Tirol, Chaco

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    El modelo educativo que tienen actualmente los niños de nuestra región nordeste no desarrolla su capacidad para elegir alimentos saludables, así van adquiriendo hábitos de alimentación no saludables que mantendrán durante toda su vida, a menos que se realice una intervención integral efectiva. La Organización de las Naciones Unidas para la Alimentación y la Agricultura (FAO) considera que los huertos escolares pueden ayudar a mejorar la nutrición y la educación de los niños y familiares, tanto en zonas rurales como urbanas, por lo que alienta a las Escuelas a crear huertos de aprendizaje que puedan ser manejados por los mismos escolares, profesores y padres, que incluyan una variedad de hortalizas y frutas. Se trabajó en una Escuela Primaria de la localidad de Puerto Tirol, Chaco, a la que asisten 575 alumnos con edades de 6 a 14 años, distribuidos en turnos mañana y tarde. Los Objetivos fueron: a) Detectar niños con alteraciones nutricionales y/o hábitos de alimentación saludables, b) Promover hábitos saludables de alimentación, y c) Promover prácticas agroecológicas al reinstalar la huerta orgánica escolar. Materiales y métodos: Se evaluó el estado nutricional y hábitos alimentarios de los alumnos a través de encuestas alimentarias, datos antropométricos y de laboratorio. Se usó la huerta como aula práctica para aprender sobre agroecología, nutrición, disfrute y esparcimiento.Se realizó asistencia técnica, acompañamiento y provisión de insumos para la producción de la huerta. Se realizaron talleres informativos con tutores y docentes, y actividades lúdicas con alumnos de ambos turnos. Resultados: Se encuestó a 258 niños (45% del total): al 99% le gustaban las frutas y al 88% las verduras, pero consumían con frecuencia un 53% frutas y un 59% verduras en sus hogares. Compraban en el kiosco escolar alimentos ricos en azúcar, sal y grasas trans. Los niños expresaron su interés en disponer de frutas y licuados en el kiosco. Respecto a los datos antropométricos sobre 150 niños, un 20 % presentaba bajo peso para su talla y un 10 % sobrepeso.Sobre los análisis de laboratorio realizados a 39 alumnos: un 15% presentaba anemia, un7,7% creatininemias bajas y ninguno elevada. La albúmina resultó normal en todos. Se reinstaló la huerta escolar con participación de alumnos de 5° a 7° grado. Las hortalizascosechadas fueron consumidas por la Escuela y por los alumnos en sus hogares.

    Modulation of higher-order olfaction components on executive functions in humans

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    The prefrontal (PFC) and orbitofrontal cortex (OFC) appear to be associated with both exec- utive functions and olfaction. However, there is little data relating olfactory processing and executive functions in humans. The present study aimed at exploring the role of olfaction on executive functioning, making a distinction between primary and more cognitive aspects of olfaction. Three executive tasks of similar difficulty were used. One was used to assess hot executive functions (Iowa Gambling Task-IGT), and two as a measure of cold executive functioning (Stroop Colour and Word Test-SCWT and Wisconsin Card Sorting Test- WCST). Sixty two healthy participants were included: 31 with normosmia and 31 with hyposmia. Olfactory abilities were assessed using the '' Sniffin ' Sticks '' test and the olfactory threshold, odour discrimination and odour identification measures were obtained. All partici- pants were female, aged between 18 and 60. Results showed that participants with hypos- mia displayed worse performance in decision making (IGT; Cohen ' s- d = 0.91) and cognitive flexibility (WCST; Cohen ' s- d between 0.54 and 0.68) compared to those with normosmia. Multiple regression adjusted by the covariates participants ' age and education level showed a positive association between odour identification and the cognitive inhibition response (SCWT-interference; Beta = 0.29; p = .034). The odour discrimination capacity was not a predictor of the cognitive executive performance. Our results suggest that both hot and cold executive functions seem to be associated with higher-order olfactory functioning in humans. These results robustly support the hypothesis that olfaction and executive mea- sures have a common neural substrate in PFC and OFC, and suggest that olfaction might be a reliable cognitive marker in psychiatric and neurologic disorders

    Decision making impairment: A shared vulnerability in obesity, gambling disorder and substance use disorders?

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    Introduction: Addictions are associated with decision making impairments. The present study explores decision making in Substance use disorder (SUD), Gambling disorder (GD) and Obesity (OB) when assessed by Iowa Gambling Task (IGT) and compares them with healthy controls (HC). Methods: For the aims of this study, 591 participants (194 HC, 178 GD, 113 OB, 106 SUD) were assessed according to DSM criteria, completed a sociodemographic interview and conducted the IGT. Results: SUD, GD and OB present impaired decision making when compared to the HC in the overall task and task learning, however no differences are found for the overall performance in the IGT among the clinical groups. Results also reveal some specific learning across the task patterns within the clinical groups: OB maintains negative scores until the third set where learning starts but with a less extend to HC, SUD presents an early learning followed by a progressive although slow improvement and GD presents more random choices with no learning. Conclusions: Decision making impairments are present in the studied clinical samples and they display individual differences in the task learning. Results can help understanding the underlying mechanisms of OB and addiction behaviors as well as improve current clinical treatments

    Activity profile of top-class association football referees in relation to fitness test performance and match standard

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    The aim of this study was to examine the kinematic activity profiles, cardiovascular responses and physical fitness of top-class football referees (n=11) during the FIFA Confederations Cup 2005. Computerised match-analyses (n=9) were performed with a two-dimensional photogrammetric video system, and the cardiovascular demand imposed on the referees (n=12) was measured using heart rate recordings. Total distance covered was 10,218, s=643 m of which 3531, s=510 m was covered at high intensities (>3.6 m.s(-1)). Both total distance covered (r2=0.59; P=0.02) and high-intensity activities (r2=0.44; P=0.05) were related to the distance covered by the ball in the same match. The referees ran at high speed 37% further (P=0.01) in the actual tournament than during under-17 top-level officiating. After the 5-min interval during which high-speed running peaked, in the following 5 min the performance was reduced by 19% (P=0.01) in relation to the mean of the game. Mean heart rate was 161, s=9 b.min(-1) (86, s=3% of maximal heart rate (HRmax)). Mean heart rate (expressed as percentage of HRmax) was related in part (r2=0.36; P5 m.s(-1)) best describes the physical performance of referees; (3) heart rate recording can be a useful tool to determine the most intense periods of a match and (4) the new fitness tests adopted by FIFA were poor predictors of match activities

    Salud de los trabajadores

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    Actividad f&iacute;sica y su relaci&oacute;n con los factores de riesgo cardiovascular de carteros chilenosAn&aacute;lisis de resultados: riesgos psicosociales en el trabajo Suceso-Istas 21 en Cesfam Quell&oacute;nAusentismo laboral por enfermedades oftalmol&oacute;gicas, Chile 2009Brote de diarreas por norovirus, posterremoto-tsunami, Constituci&oacute;n, Regi&oacute;n del MauleCalidad de vida en profesionales de la salud p&uacute;blica chilenaCaracterizaci&oacute;n del reposo laboral en personal del SSMN durante el primer semestre de 2010Concentraci&oacute;n de nicotina en pelo en trabajadores no fumadores expuestos a humo de tabaco ambientalCondiciones de trabajo y bienestar/malestar docente en profesores de ense&ntilde;anza media de SantiagoDisfunci&oacute;n auditiva inducida por exposici&oacute;n a xilenoErgonom&iacute;a aplicada al estudio del s&iacute;ndrome de dolor lumbar en el trabajoEstimaci&oacute;n de la frecuencia de factores de riesgo cardiovascular en trabajadores de una empresa mineraExposici&oacute;n a plaguicidas inhibidores de la acetilcolinesterasa en Colombia, 2006-2009Factores de riesgo y da&ntilde;os de salud en conductores de una empresa peruana de transporte terrestre, 2009Las consecuencias de la cultura en salud y seguridad ocupacional en una empresa mineraPercepci&oacute;n de cambios en la pr&aacute;ctica m&eacute;dica y estrategias de afrontamientoPercepci&oacute;n de la calidad de vida en la Universidad del Biob&iacute;oPesos m&aacute;ximos aceptables para tareas de levantamiento manual de carga en poblaci&oacute;n laboral femeninaRiesgo coronario en trabajadores mineros seg&uacute;n la funci&oacute;n de Framingham adaptada para la poblaci&oacute;n chilenaTrastornos emocionales y riesgo cardiovascular en trabajadores de la salu
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