1000 resultados para test de aprendizaje


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Currently, no standard mix design procedure is available for CIR-emulsion in Iowa. The CIR-foam mix design process developed during the previous phase is applied for CIR-emulsion mixtures with varying emulsified asphalt contents. Dynamic modulus test, dynamic creep test, static creep test and raveling test were conducted to evaluate the short- and long-term performance of CIR-emulsion mixtures at various testing temperatures and loading conditions. A potential benefit of this research is a better understanding of CIR-emulsion material properties in comparison with those of CIR-foam material that would allow for the selection of the most appropriate CIR technology and the type and amount of the optimum stabilization material. Dynamic modulus, flow number and flow time of CIR-emulsion mixtures using CSS-h were generally higher than those of HFMS-2p. Flow number and flow time of CIR-emulsion using RAP materials from Story County was higher than those from Clayton County. Flow number and flow time of CIR-emulsion with 0.5% emulsified asphalt was higher than CIR-emulsion with 1.0% or 1.5%. Raveling loss of CIR-emulsion with 1.5% emulsified was significantly less than those with 0.5% and 1.0%. Test results in terms of dynamic modulus, flow number, flow time and raveling loss of CIR-foam mixtures are generally better than those of CIR-emulsion mixtures. Given the limited RAP sources used for this study, it is recommended that the CIR-emulsion mix design procedure should be validated against several RAP sources and emulsion types.

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The slow-phase velocity of nystagmus is one of the most sensitive parameters of vestibular function and is currently the standard for evaluating the caloric test. However, the assessment of this parameter requires recording the response by using nystagmography. The aim of this study was to evaluate whether frequency and duration of the caloric nystagmus, as measured by using a clinical test with Frenzel glasses, could predict the result of the recorded test. The retrospective analysis of 222 caloric test results recorded by means of electronystagmography has shown a good association between the 3 parameters for unilateral weakness. The asymmetry observed in the velocity can be predicted by a combination of frequency and duration. On the other hand, no relationship was observed between the parameters for directional preponderance. These results indicate that a clinical caloric test with frequency and duration as parameters can be used to predict the unilateral weakness, which would be obtained by use of nystagmography. We propose an evaluation of the caloric test on the basis of diagrams combining the 3 response parameters.

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A modified magnesium hydrogen breath test, using end expiratory breath sampling, is described to investigate achlorhydria. The efficacy of this test in the diagnostic investigation of pernicious anaemia was compared with that of serum pepsinogen I. Twenty one patients with pernicious anaemia--that is, patients with achlorhydria--and 22 with healed duodenal ulcer and normal chlorhydria were studied. Magnesium hydrogen breath test, serum pepsinogen I, serum gastrin, and standard gastric acid secretory tests were performed in all subjects. The mean (SEM) hydrogen peak value was lower in patients with pernicious anaemia than in the duodenal ulcer group (21.7 (1.9) v 71.3 (5.2) ppm; p = 0.00005). The hydrogen peak value had a 95.2% sensitivity and a 100% specificity to detect pentagastrin resistant achlorhydria. Mean serum pepsinogen I concentrations were also significantly lower in patients with pernicious anaemia than in the duodenal ulcer group (10.7 (2.7) v 123.6 (11.8) micrograms/l p = 0.00005). Sensitivity and specificity to detect pernicious anaemia were both 100% for pepsinogen I. It is concluded that this modified magnesium hydrogen breath test is a simple, noninvasive, cost effective, and accurate method to assess achlorhydria and may be useful in the diagnostic investigation of patients with suspected pernicious anaemia.

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Este trabajo pretende ser, la exhibición de las competencias adquiridas en materia de investigación, a través de la integración coherente entre la reelaboración teórica, y el diseño de instrumentos de valoración que aporten evidencias válidas y confiables sobre la contribución del "e-Diario compartido", en el desarrollo de las competencias transversales de pensamiento crítico-reflexivo y aprendizaje autónomo.El trabajo representa una primera fase de elaboración, que debe ser profundizada en el futuro inmediato, y por ello plantea un marco general para la evaluación de la experiencia pedagógica: Uno, desde sus elementos conceptuales como innovación educativa que es, y; Dos, a través de sus resultados, en términos del aprendizaje de los participantes competencias desarrolladas.

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BACKGROUND: The objective is to develop a cost-effective, reliable and non invasive screening test able to detect early CRCs and adenomas. This is done on a nucleic acids multigene assay performed on peripheral blood mononuclear cells (PBMCs). METHODS: A colonoscopy-controlled study was conducted on 179 subjects. 92 subjects (21 CRC, 30 adenoma >1 cm and 41 controls) were used as training set to generate a signature. Other 48 subjects kept blinded (controls, CRC and polyps) were used as a test set. To determine organ and disease specificity 38 subjects were used: 24 with inflammatory bowel disease (IBD),14 with other cancers (OC). Blood samples were taken and PBMCs were purified. After the RNA extraction, multiplex RT-qPCR was applied on 92 different candidate biomarkers. After different univariate and multivariate analysis 60 biomarkers with significant p-values (<0.01) were selected. 2 distinct biomarker signatures are used to separate patients without lesion from those with CRC or with adenoma, named COLOX CRC and COLOX POL. COLOX performances were validated using random resampling method, bootstrap. RESULTS: COLOX CRC and POL tests successfully separate patients without lesions from those with CRC (Se 67%, Sp 93%, AUC 0.87), and from those with adenoma > 1cm (Se 63%, Sp 83%, AUC 0.77). 6/24 patients in the IBD group and 1/14 patients in the OC group have a positive COLOX CRC. CONCLUSION: The two COLOX tests demonstrated a high Se and Sp to detect the presence of CRCs and adenomas > 1 cm. A prospective, multicenter, pivotal study is underway in order to confirm these promising results in a larger cohort.

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Partiendo de un principio de continuidad evolutiva en los mecanismos y estructura de la función simbólica en el reino animal, se implanta el equivalente funcional de una palabra (Tact) en la rata blanca. Siguiendo a la mayor parte de los trabajos de implantación de lenguaje artificial en animales, se utilizan las técnicas de condicionamientc operante con una primera fase de aprendizaje, para dejar al sujeto una libre utilización de la relación funcional simbólica en la segunda fase (inversión).

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The functional response of predators is usually modelled as a function of absolute prey density. Arditi and Ginzburg have suggested that it should often depend instead on the prey available per capita of predators, i.e. on the prey/predator ratio. Theory suggests that these two forms of dependence are related to the degree of spatial and temporal heterogeneity. Experiments using four filter-feeding cladoceran species were designed to test this hypothesis and to investigate the relation between individual behaviour and population dynamics. The patterns of population abundance that the cladocerans reached at equilibrium match the expectation that species with homogeneous spatial behaviour follow prey-dependent dynamics while those with heterogeneous behaviour follow ratio-dependent dynamics.

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Variable queen mating frequencies provide a unique opportunity to study the resolution of worker-queen conflict over sex ratio in social Hymenoptera, because the conflict is maximal in colonies headed by a singly mated queen and is weak or nonexistent in colonies headed by a multiply mated queen. In the wood ant Formica exsecta, workers in colonies with a singly mated queen, but not those in colonies with a multiply mated queen, altered the sex ratio of queen-laid eggs by eliminating males to preferentially raise queens. By this conditional response to queen mating frequency, workers enhance their inclusive fitness.

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Comunicació presentada a les 4as Jornadas OS Repositorios: Políticas de promoción del acceso abierto". Barcelona 3-5 de marzo de 2010

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Este trabajo presenta una experiencia innovadora en la formación de pregrado de estudiantes de psicología de la Universidad de Talca. Para ello se diseñó un ambiente de aprendizaje sustentado en la metodología de aprendizaje basado en problemas, con el propósito de mejorar las capacidades de toma de decisiones de los futuros psicólogos frente a una posible intervención en un contexto educativo. Los resultados de la experiencia mostraron un leve aumento en el desempeño estudiantil, mayor compromiso y participación, autogestión en la búsqueda de información y capacidad de problematización en los estudiantes.

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With the use of supplementary cementing materials (SCMs) in concrete mixtures, salt scaling tests such as ASTM C672 have been found to be overly aggressive and do correlate well with field scaling performance. The reasons for this are thought to be because at high replacement levels, SCM mixtures can take longer to set and to develop their properties: neither of these factors is taken into account in the standard laboratory finishing and curing procedures. As a result, these variables were studied as well as a modified scaling test, based on the Quebec BNQ scaling test that had shown promise in other research. The experimental research focused on the evaluation of three scaling resistance tests, including the ASTM C672 test with normal curing as well as an accelerated curing regime used by VDOT for ASTM C1202 rapid chloride permeability tests and now included as an option in ASTM C1202. As well, several variations on the proposed draft ASTM WK9367 deicer scaling resistance test, based on the Quebec Ministry of Transportation BNQ test method, were evaluated for concretes containing varying amounts of slag cement. A total of 16 concrete mixtures were studied using both high alkali cement and low alkali cement, Grade 100 slag and Grade 120 slag with 0, 20, 35 and 50 percent slag replacement by mass of total cementing materials. Vinsol resin was used as the primary air entrainer and Micro Air® was used in two replicate mixes for comparison. Based on the results of this study, a draft alternative test method to ASTM C762 is proposed.