1,048 research outputs found

    Desarrollo del razonamiento sobre pruebas de significación de estudiantes de bachillerato en un ambiente tecnológico

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    Se describe el desarrollo del razonamiento de 36 estudiantes de bachillerato, organizados en parejas, acerca de la técnica de pruebas de significación estadística con el apoyo de un software educativo de estadística (Fathom); dicho desarrollo es visto a través de sus respuestas a 4 problemas de pruebas de significación; estos se resolvieron en sendas sesiones en las que además se realizaron cortas intervenciones del profesor, se enseñó a utilizar el software y se discutieron dudas de los problemas vistos en la sesión previa respectiva. Las respuestas a cada problema se clasificaron en niveles SOLO. Los resultados muestran avances en la calidad de las respuestas de los participantes, superándose en cada actividad algunos errores cometidos en la previa, esto lleva conjeturar que los estudiantes se van apropiando del esquema de pruebas de significación. No obstante, se presentan algunas dificultades similares a las ya reportadas en la literatura

    Nuevas gentes y nueva sangre, pero las mismas reglas del juego. El concejo de baza en el siglo XVIII

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    In the pages that follow I will explain the social assimilation carried out in the spheres of the municipal power of the city of Baza. Studying, on one hand, the traditional oligarchy, established in the town council since the conquest times, pooled around their ranks key representation positions; and on the other hand, to a group of new people who, thanks to their flourishing economic power, waited until the 18th-century to assault the local offices and institutions, allowing with these strategies a total regeneration of the system.Las páginas que siguen tratan de explicar la asimilación social llevada a cabo en las esferas del poder municipal de la ciudad de Baza. Estudiando, por un lado, a la oligarquía tradicional, asentada en el cabildo desde los tiempos de la conquista y que había ido aglutinando en torno a sus filas los principales cargos de representación; y por otro, a un grupo de gentes nuevas que, gracias a su floreciente poderío económico, esperaron al siglo XVIII para asaltar los oficios e instituciones locales. Permitiendo la regeneración total del sistemao

    Nuevas gentes y nueva sangre, pero las mismas reglas del juego. El concejo de baza en el siglo XVIII

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    In the pages that follow I will explain the social assimilation carried out in the spheres of the municipal power of the city of Baza. Studying, on one hand, the traditional oligarchy, established in the town council since the conquest times, pooled around their ranks key representation positions; and on the other hand, to a group of new people who, thanks to their flourishing economic power, waited until the 18th-century to assault the local offices and institutions, allowing with these strategies a total regeneration of the system.Las páginas que siguen tratan de explicar la asimilación social llevada a cabo en las esferas del poder municipal de la ciudad de Baza. Estudiando, por un lado, a la oligarquía tradicional, asentada en el cabildo desde los tiempos de la conquista y que había ido aglutinando en torno a sus filas los principales cargos de representación; y por otro, a un grupo de gentes nuevas que, gracias a su floreciente poderío económico, esperaron al siglo XVIII para asaltar los oficios e instituciones locales. Permitiendo la regeneración total del sistemao

    Reliability of the resonance frequency analysis values in new prototype transepithelial abutments: A prospective clinical study

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    Resonance frequency analysis (RFA) requires abutment disconnection to monitor implant stability. To overcome this limitation, an experimental transepithelial abutment was designed to allow a SmartPeg to be screwed onto it, in order to determine the prototype abutments repeatability and reproducibility using Osstell ISQ and to assess whether implant length and diameter have an influence on the reliability of these measurements. RFA was conducted with a SmartPeg screwed directly into the implant and onto experimental abutments of different heights of 2, 3.5 and 5 mm. A total of 32 patients (116 implants) were tested. RFA measurements were taken twice for each group from mesial, distal, buccal and palatal/lingual surfaces. Mean values and SD were calculated and Intraclass Correlation Coefficients (ICC) (p < 0.05, IC 95%). The implant stability quotient (ISQ) mean values were 72.581 measured directly to implant and 72.899 (2 mm), 72.391 (3.5 mm) and 71.458 (5 mm) measured from the prototypes. ICC between measurements made directly to implant and through 2-, 3.5-and 5-mm abutments were 0.908, 0.919 and 0.939, respectively. RFA values registered through the experimental transepithelial abutments achieved a high reliability. Neither the implant length nor the diameter had any influence on the measurements’ reliability

    Net sea-air CO2 flux uncertainties in the Bay of Biscay based on the choice of wind speed products and gas transfer parameterizations

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    25 páginas, 4 figuras, 1 tablaThe estimation of sea-air CO2 fluxes are largely dependent on wind speed through the gas transfer velocity parameterization. In this paper, we quantify uncertainties in the estimation of the CO2 uptake in the Bay of Biscay resulting from using different sources of wind speed such as three different global reanalysis meteorological models (NCEP/NCAR 1, NCEP/DOE 2 and ERA-Interim), one regional high-resolution forecast model (HIRLAM-AEMet) and QuikSCAT winds, in combination with some of the most widely used gas transfer velocity parameterizations. Results show that net CO2 flux estimations during an entire seasonal cycle may differ up to 240% depending on the wind speed product and the gas exchange parameterization. The comparison of satellite and model derived winds with observations at buoys advises against the systematic overestimation of NCEP-2 and the underestimation of NCEP-1. In this region, QuikSCAT has the best performing, although ERA-Interim becomes the best choice in areas near the coastline or when the time resolution is the constraint.This work was developed and funded by the ECO project (MCyT REN2002-00503/MAR) and EU FP7 project CARBOCHANGE “Changes 5 in carbon uptake and emissions by oceans in a changing climate” under agreement no. 264879Peer reviewe

    Diabetes insípida central en un perro

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    Se describe un caso de diabetes insípida central [DIC] en un perro. Este caso es particularmente interesante pues se observan modificaciones electrolíticas poco habituales. En la discusión se comenta la posible etiología del proceso, los hallazgos analíticos y el procedimiento de diagnóstico elegido.It is described a case of canine central diabetes insipidus particularly interesting because is presented with very un usual electrolytic abnormalities. The etiology, the atypical electrolytic levels observed and the diagnostic method used are discussed

    A MWCNTs-COOH/PSS nanocomposite–modified screen-printed electrode for the determination of synthetic phenolic antioxidants by HPLC with amperometric detection

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    New sensing platforms based on screen-printed carbon electrodes modifed with composites based on polystyrene sulfonate and oxidized multi-walled carbon nanotubes (PSS/MWCNTs-COOH/SPCE) have been used to develop a novel HPLC method with electrochemical detection (ECD) for the determination of the most used synthetic phenolic antioxidants in cosmetics: butylhydroxytoluene (BHT), butylhydroxyanisole (BHA), tert-butylhydroquinone (TBHQ) and propyl gallate (PG). Optimal separation conditions were achieved using methanol: 0.10 mol L−1 acetate solution at pH 6 as mobile phase with a gradient elution program from 60 to 90% of methanol percentage in 15 min. The electrochemical detection was carried out in amperometric mode using the PSS/MWCNTs-COOH/SPCE at+0.80 V vs. Ag. Under these optimal separation and detection conditions, the limits of detection (LOD) were between 0.11 and 0.25 mg L−1. These LOD values were better, especially for BHT, than those previously published in other HPLC methods. Linear ranges from 0.37 mg L−1, 0.83 mg L−1, 0.69 mg L−1 and 0.56 mg L−1 to 10 mg L−1 were obtained for PG, TBHQ, BHA and BHT, respectively. RSD values equal or lower than 5% and 8% were achieved for repeatability and reproducibility, respectively. The HPLC-ECD method was successfully applied to analyze diferent cosmetic samples. Recovery values within 83–109% were obtained in the validation studiesOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Natur

    ATR-FTIR as a potential tool for controlling high quality vinegar categories

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    Characterization of wine vinegars qualified with a Protected Designation of Origin (PDO) is crucial to certify their quality and authenticity. Spectroscopic techniques as Fourier transform mid infrared spectroscopy (FTIR) with Attenuated Total Reflectance (ATR) has been applied to investigate its potential as a rapid, cost-effective and non-destructive tool for characterizing different categories of high-quality vinegars. Spectra from 67 wine vinegars belonging to the PDOs “Vinagre de Jerez” and “Vinagre Condado de Huelva”, including their different established categories, were analyzed in the 4000–600 cm−1 infrared region. Changes associated to categories were observed in the region 1800–900 cm−1. These changes were assigned to certain compounds that increase during aging (e.g. acetic acids, alcohols, esters) or are characteristic of Pedro Ximenez category (e.g. sugars, furfural). Principal component analysis carried out on the most relevant spectral features, revealed that aging of vinegars clearly affect the ATR-FTIR spectra obtained in each PDO.Junta de Andalucía P12-AGR-160

    Sacrolistesis postraumática sin lesión neurológica

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    Las fracturas transversas de sacro son raras pero aún lo son más aquellas en las que hay un desplazamiento o listeis de una vértebra sacra sobre otra. El sentido de desplazamiento viene condicionado por el mecanismo causante, pudiendo ser en flexión o en extensión. En las verdaderas listesis el sentido del traumatismo es en extensión, llevando a colocarse total o parcialmente la vértebra sacra superior por delante de la inferior. En determinados casos como pueden ser los politraumatizados, el diagnóstico puede ser difícil, por lo que es necesario realizar un estudio radiológico meticuloso. En estas fracturas ocurre frecuentemente una lesión de raíces lumbosacras de mayor o menor gravedad, aunque suele existir algún tipo de recuperación, incluso espontánea, con el transcurso del tiempo. Se presenta el caso de una mujer que presentó una sacrolistesis de S1 sobre S2 por haber sufrido caída de nalgas, sin existir ninguna lesión neurológica.Transverse fractures of the sacrum are rare, but fractures with displacement or listhesis of one sacral vertebra over another are even more infrequent. The direction of the displacement is conditioned by the causing mechanism and may occur in flexion or extension, in true listhesis, trauma occurs in extension, placing the superior sacral vertebra totally or partially in from of the inferior vertebra. In some cases, such as multiple traumas, the diagnosis can be difficult, and a careful radiologic study is required. A more or less severe injury of th lumbosacral roots frequently occurs in these fractures, although a certain degree of recovery takes place, even spontaneously, over time. We present the case of a 69 years old woman suffering from a sacrolisthesis of S1 over S2 after a fall on the buttocks with no neurological lesion
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