79 research outputs found

    Estudio de la capacidad estabilizadora del peroné en fracturas de tibia de conejo

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    El objetivo de este trabajo es estudiar la capacidad estabilizadora del peroné en fracturas de tibia. Si dicha capacidad es suficiente, sería posible evitar el uso de sistemas de fijación en los experimentos de laboratorio con este tipo de fracturas. Para comprobarlo se ha realizado una simulación computacional por elementos finitos de la tibia y el peroné de un conejo, con una fractura en el tercio medio superior de la diáfisis sin ningún elemento estabilizador. El conjunto ha sido sometido a las cargas más desfavorables del proceso de salto comprobándose que en este caso el peroné fracturaría en su parte inferior del mismo modo que sucede en la experimentación en laboratorio

    Evaluation and optimization of the Sysmex UF1000i system for the screening of urinary tract infection in primary health care elderly patients

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    Objective Urinary tract infections (UTIs) are a common problem in the elderly population. Urine culture is still considered the "gold standard" to diagnose infection in this population. However, urine cultures are laborious and costly, and most samples will yield no growth. Methods An evaluation was made of the Sysmex UF-1000i flow cytometer as a screening tool for UTI in an elderly population older than 65 years who lived in the community, using 346 urine samples submitted for culture. Results The Receiver Operating Characteristic (ROC) analysis showed a significant difference (P < 0.01) between 0.98 bacteria area under the curve value and 0.82 of white blood cells (WBC). The combination of both counts for screening did not show any improvement in specificity or sensitivity. According to our data, the use of a single cut-off point of 200 bacteria/μL is suggested, in which the sensitivity and specificity were 99.11% and 91.59%, respectively, with a NPV of 99.49%. Moreover, this cut-off value could avoid 60.24% of the samples to be cultured, with a minimal false negative results rate of 0.87%. Conclusions The stratification of age groups stratification helps in selecting a more adjusted Sysmex UF1000i cut-off limit, leading to an improvement in the screening parameters that would imply a better management of these infections, as well as a high reduction in the workload and cost savings

    Bloom’s taxonomy and the application of knowledge: problem-based learning in the subject ‘Zoology’ at the University of Valencia

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    De acuerdo con la taxonomía de Bloom, en el contexto de la enseñanza los procesos cognitivos se encuentran jerarquizados en seis niveles de complejidad creciente e inclusiva. Así, una materia puede perseguir que los studiantes (1) memoricen información, (2) la comprendan, (3) la apliquen para resolver problemas nuevos, (4) la analicen, (5) la evalúen o (6) incluso creen nuevo conocimiento a partir de ella. Tradicionalmente, en las universidades españolas la asignatura de Zoología ha promovido primordialmente la memorización y la comprensión. Sin embargo, parece hoy recomendable trabajar también procesos cognitivos superiores, haciendo hincapié en la aplicación del conocimiento zoológico. Esto proporciona herramientas a los estudiantes para abordar una gran variedad de preguntas, ayudando a forjar un estilo de pensamiento; permite adaptar los contenidos a una menor presencialidad, generando autonomía en la forma de trabajar, y desplaza el énfasis epistemológico desde una ciencia de sujetos hacia una ciencia de principios. En este trabajo presentamos un diseño realista de clases de problemas de zoología para grupos numerosos, tal y como se plantea en la Universidad de Valencia. El elemento clave de nuestra iniciativa es una selección muy cuidadosa de los problemas: no se trata de memorizar o comprender debates clásicos o recientes en zoología, ni de meros ejercicios de corroboración. Los problemas de aplicación que planteamos obligan al estudiante a buscar relaciones o consecuencias no inmediatas de los conocimientos que van adquiriendo sobre filogenia, diversidad, planes corporales, morfología funcional y estrategias vitales; intentamos además que incluyan filos que no se tratan en el temario. En este trabajo ilustramos diversos problemas tipo y describimos qué temporalización, carga docente y metodología pueden resultar más adecuadas dentro de un programa “clásico” de Zoología. El criterio fundamental de evaluación es que las respuestas sean plausibles, aunque no necesariamente correctas.According to Bloom’s taxonomy, the cognitive processes that are involved in any learning context can be organized into six inclusive levels of increasing complexity. The aim(s) of any academic subject can be (1) to memorize information, (2) to understand it, (3) to apply it to solve new problems, (4) to analyze it, (5) to evaluate it, and even (6) to create new knowledge based on it. Traditionally, in Spanish universities the subject ‘Zoology’ has primarily addressed memorization and understanding. However, it would seem advisable to also deal with upper cognitive processes, particularly the application of knowledge. This would allow students to tackle a great diversity of zoology questions, help creating a thinking style, and to reduce the number of lectures since students could deal with several contents by themselves. Also, the application of knowledge would shift emphasis from subjects (animals) to principles. In this presentation we describe a realistic design for problem-based lectures on zoology that are devised for large classes at the University of Valencia. The key element for a successful implementation is a careful selection of problems. Applying knowledge has nothing to do with memorizing / understanding classical or current zoological debates, or with making corroborative exercises. A genuine problem invites students to seek relationships and non-trivial consequences of the knowledge they acquire about phylogeny, diversity, body plans, functional morphology, and life history strategies, particularly when they are applied to animal phyla that are not included in the subject programme. In this presentation we include type problems and describe the schedule, teaching load and methodology that could best fit within a “classical” Zoology programme. The fundamental criterion to evaluate problems is that answers are plausible, though not necessarily correc

    Low Background Micromegas in CAST

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    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 106^{-6} counts/keV/cm2^2/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 107^{-7} counts/keV/cm2^2/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as the strategies to further reduce the background level. Finally, we will describe the R&D paths to achieve sub-keV energy thresholds, which could broaden the physics case of axion helioscopes.Comment: 6 pages, 3 figures, Large TPC Conference 2014, Pari

    Progress in Detection and Projection of Climate Change in Spain since the 2010 CLIVAR-Spain regional climate change assessment report

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    The Iberian Peninsula region offers a challenging benchmark for climate variability studies for several reasons. It exhibits a wide variety of climatic regimes, ranging from wet Atlantic climates with annual precipitation around 2000 mm, to extensive semiarid regions with severe hydrological stress, to even cold alpine environments in some isolated areas

    Micromegas for dark matter searches: CAST/IAXO & TREX-DM experiments

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    The most compelling candidates for Dark Matter to day are WIMPs and axions. The applicability of gasesous Time Projection Chambers (TPCs) with Micromesh Gas Structures (Micromegas) to the search of these particles is explored within this work. Both particles would produce an extremely low rate at very low energies in particle detectors. Micromegas detectors can provide both low background rates and low energy threshold, due to the high granularity, radiopurity and uniformity of the readout. Small (few cm wide) Micromegas detectors are used to image the ax ion-induced x-ray signal expected in the CERN Axion Solar Telescope (CAST) experiment. We show the background levels obtained in CAST and the prospects to further reduce them to the values required by the Internation Axion Observatory (IAXO). We also present TREX-DM. a scaled-up version of the Micromegas used in axion research, but this time dedicated to the low-mass WIMP detection. TREX-DM is a high-pressure Micromegas-based TPC designed to host a few hundreds of grams of light nuclei (argon or neon) with energy thresholds potentially at the level of 100 eV. The detector is described in detail, as well as the results of the commissioning and characterization phase on surface. Besides, the background model of TREX-DM is presented, along with the anticipated sensitivity of this search, which could go beyond current experimental limits

    Development and Testing of a New Instrument for Researching on Cancer Treatment Technologies Based on Magnetic Hyperthermia

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    (c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.A power electronics circuit allows the generation of high-frequency magnetic field that can be used to increase the temperature of cancer cells previously invaded with the magnetic nanoparticles. The circuit designed for this purpose is a high-frequency phase-shift inverter implemented with SiC devices and natural zero voltage switching. The inductive load has been optimized to increase as much as possible the magnetic field at the center of it considering the physical restrictions. Into this inductor, an adiabatic probe filled with nanoparticles is placed being the main objective to increase its temperature. The control of the inverter has been designed in such a way that it is easy to try waveforms different from the classical sine waves to see its effect on the temperature of the sample. Although the research is in one of the early stages, the first conclusions about the optimal frequency and field have been obtained showing that this technique could be a real option in the future.García, O.; Moreno-Arrones, N.; Cuesta, A.; Gutierrez, A.; Alou, P.; Oliver, J.; Cobos, J.... (2016). Development and Testing of a New Instrument for Researching on Cancer Treatment Technologies Based on Magnetic Hyperthermia. IEEE Journal of Emerging and Selected Topics in Power Electronics. 4(1):243-251. https://doi.org/10.1109/JESTPE.2015.2479092S2432514

    Gender differences in the incidence of and risk factors for hip fracture: A 16-year longitudinal study in a southern European population

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    Objectives To analyze independently in men and women the incidence rate of and risk factors for hip fracture in a southern European population. Illiteracy, dementia, clinically significant depression and disability were factors to receive special emphasis. Study design A community sample of 4803 individuals aged over 55 years was assessed in a two-phase case-finding study in Zaragoza, Spain, and was followed up for 16 years. Medical history and psychiatric history were collected with standardized instruments, including the History and Aetiology Schedule, the Geriatric Mental State (GMS) scale, and a Risk Factors Questionnaire. Operational criteria were used to define covariates, including diagnostic criteria for both dementia and depression. The statistical analysis included calculations of incidence rate, IR; women/men incidence rate ratio (IRR); and Hazard Ratios (HR) in multivariate Cox proportional hazards regression models. Main outcome measures Cases of hip fracture (International Classification of Diseases, WHO) identified in the treating hospitals, validated by blinded researchers. Results Hip fractures were more frequent among women than men (IRR = 3.1). Illiteracy (HR = 1.55) and depression (HR = 1.44) increased the risk in women, and smoking (HR = 2.13) and disability in basic activities of daily living (HR = 3.14) increased the risk in men. Dementia was associated with an increased risk in an univariate analysis, but the association disappeared (power = 85% in men, 95% in women) when disability was included in the multivariate models. Conclusions The IR of hip fractures was three times higher among women. Illiteracy and clinically significant depression among women and active smoking and disability (HR = 3.14) among men independently increased the risk, but dementia did not

    LMO2 expression reflects the different stages of blast maturation and genetic features in B-cell acute lymphoblastic leukemia and predicts clinical outcome

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    BACKGROUND: LMO2 is highly expressed at the most immature stages of lymphopoiesis. In T-lymphocytes, aberrant LMO2 expression beyond those stages leads to T-cell acute lymphoblastic leukemia, while in B cells LMO2 is also expressed in germinal center lymphocytes and diffuse large B-cell lymphomas, where it predicts better clinical outcome. The implication of LMO2 in B-cell acute lymphoblastic leukemia must still be explored. DESIGN AND METHODS: We measured LMO2 expression by real time RT-PCR in 247 acute lymphoblastic leukemia patient samples with cytogenetic data (144 of them also with survival and immunophenotypical data) and in normal hematopoietic and lymphoid cells. RESULTS: B-cell acute lymphoblastic leukemia cases expressed variable levels of LMO2 depending on immunophenotypical and cytogenetic features. Thus, the most immature subtype, pro-B cells, displayed three-fold higher LMO2 expression than pre-B cells, common-CD10+ or mature subtypes. Additionally, cases with TEL-AML1 or MLL rearrangements exhibited two-fold higher LMO2 expression compared to cases with BCR-ABL rearrangements or hyperdyploid karyotype. Clinically, high LMO2 expression correlated with better overall survival in adult patients (5-year survival rate 64.8% (42.5%-87.1%) vs. 25.8% (10.9%-40.7%), P= 0.001) and constituted a favorable independent prognostic factor in B-ALL with normal karyotype: 5-year survival rate 80.3% (66.4%-94.2%) vs. 63.0% (46.1%-79.9%) (P= 0.043). CONCLUSIONS: Our data indicate that LMO2 expression depends on the molecular features and the differentiation stage of B-cell acute lymphoblastic leukemia cells. Furthermore, assessment of LMO2 expression in adult patients with a normal karyotype, a group which lacks molecular prognostic factors, could be of clinical relevance

    Magnetic Field Generation in Stars

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    Enormous progress has been made on observing stellar magnetism in stars from the main sequence through to compact objects. Recent data have thrown into sharper relief the vexed question of the origin of stellar magnetic fields, which remains one of the main unanswered questions in astrophysics. In this chapter we review recent work in this area of research. In particular, we look at the fossil field hypothesis which links magnetism in compact stars to magnetism in main sequence and pre-main sequence stars and we consider why its feasibility has now been questioned particularly in the context of highly magnetic white dwarfs. We also review the fossil versus dynamo debate in the context of neutron stars and the roles played by key physical processes such as buoyancy, helicity, and superfluid turbulence,in the generation and stability of neutron star fields. Independent information on the internal magnetic field of neutron stars will come from future gravitational wave detections. Thus we maybe at the dawn of a new era of exciting discoveries in compact star magnetism driven by the opening of a new, non-electromagnetic observational window. We also review recent advances in the theory and computation of magnetohydrodynamic turbulence as it applies to stellar magnetism and dynamo theory. These advances offer insight into the action of stellar dynamos as well as processes whichcontrol the diffusive magnetic flux transport in stars.Comment: 41 pages, 7 figures. Invited review chapter on on magnetic field generation in stars to appear in Space Science Reviews, Springe
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