456 research outputs found
Theories of developmental dyslexia: Insights from a multiple case study of dyslexic adults
A multiple case study was conducted in order to assess three leading theories of developmental dyslexia: the phonological, the magnocellular (auditory and visual) and the cerebellar theories. Sixteen dyslexic and 16 control university students were administered a full battery of psychometric, phonological, auditory, visual and cerebellar tests. Individual data reveal that all 16 dyslexics suffer from a phonological deficit, 10 from an auditory deficit, 4 from a motor deficit, and 2 from a visual magnocellular deficit. Results suggest that a phonological deficit can appear in the absence of any other sensory or motor disorder, and is sufficient to cause a literacy impairment, as demonstrated by 5 of the dyslexics. Auditory disorders, when present, aggravate the phonological deficit, hence the literacy impairment. However, auditory deficits cannot be characterised simply as rapid auditory processing problems, as would be predicted by the magnocellular theory. Nor are they restricted to speech. Contrary to the cerebellar theory, we find little support for the notion that motor impairments, when found, have a cerebellar origin, or reflect an automaticity deficit. Overall, the present data support the phonological theory of dyslexia, while acknowledging the presence of additional sensory and motor disorders in certain individuals
Assessment of electrophoresis and electroosmosis in construction materials: effect of enhancing electrolytes and heavy metals contamination
Electrokinetic effects are those that take place by application of an electric field to porous materials, with the zeta potential as the key parameter. Specifically, in the case of contaminated construction materials, the generation of an electroosmotic flux, with the corresponding dragging due to water transport, is a crucial mechanism to succeed in the treatment of decontamination. Therefore, it is of great interest trying to optimize the treatment by the addition of specific electrolytes enhancing the electrokinetic phenomena. Most of the data of zeta potential found in literature for construction materials are based in micro-electrophoresis measurements, which are quite far of the real conditions of application of the remediation treatments. In this paper, electrophoretic and electroosmotic experiments, with monolithic and powdered material respectively, have been carried out for mortar, brick and granite clean and contaminated with Cs, Sr, Co, Cd, Cu and Pb. The electrolytes tested have been distilled water (DW), Na2–EDTA, oxalic acid, acetic acid and citric acid. The zeta potential values have been determined through the two different techniques and the results compared and critically analysed
Directrices para evaluar la puesta en valor de un residuo en la fabricación de un material base cemento: producción de hormigón autocompactante a partir de sedimentos dragados
This article presents some guidelines in order to analyse the feasibility of including a waste material in the production of a structural cementitious material. First of all, the compatibility of the waste with a cementitious material has to be assured; then, if necessary, a decontamination step will be carried out; after, decision on the type of material has to be taken based on different aspects, with special emphasis on the granulometry. As a last step, mechanical, environmental and durability properties have to be evaluated. Then the procedure is illustrated with a full example, obtaining a self compacting concrete (SCC) including dredged sediment taken from a Spanish harbour.Este artículo presenta algunas directrices con el fin de analizar la posibilidad de incluir un material de desecho en la producción de un material base cemento estructural. En primer lugar, debe asegurarse la compatibilidad de los residuos con el material base cemento. Tras ello, si es necesario, se llevará a cabo la etapa de descontaminación del residuo. Después debe tomarse la decisión sobre el tipo de material a utilizar en base a diferentes aspectos, haciendo especial énfasis en la granulometría. Como último paso, deben evaluarse las propiedades mecánicas, ambientales y de durabilidad del producto final. El procedimiento a seguir se ilustra con un ejemplo concreto basado en la obtención de un hormigón autocompactante (SCC) incluyendo en su fabricación sedimentos dragados tomados de un puerto español
Kinematic and kinetic patterns related to free-walking in Parkinson's disease
The aim of this study is to compare the properties of free-walking at a natural pace
between mild Parkinson’s disease (PD) patients during the ON-clinical status and two control groups.
In-shoe pressure-sensitive insoles were used to quantify the temporal and force characteristics of a
5-min free-walking in 11 PD patients, in 16 young healthy controls, and in 12 age-matched healthy
controls. Inferential statistics analyses were performed on the kinematic and kinetic parameters
to compare groups’ performances, whereas feature selection analyses and automatic classification
were used to identify the signature of parkinsonian gait and to assess the performance of group
classification, respectively. Compared to healthy subjects, the PD patients’ gait pattern presented
significant differences in kinematic parameters associated with bilateral coordination but not in
kinetics. Specifically, patients showed an increased variability in double support time, greater gait
asymmetry and phase deviation, and also poorer phase coordination. Feature selection analyses
based on the ReliefF algorithm on the differential parameters in PD patients revealed an effect of
the clinical status, especially true in double support time variability and gait asymmetry. Automatic
classification of PD patients, young and senior subjects confirmed that kinematic predictors produced
a slightly better classification performance than kinetic predictors. Overall, classification accuracy of
groups with a linear discriminant model which included the whole set of features (i.e., demographics
and parameters extracted from the sensors) was 64.1
Potenciación de la respuesta inmune humoral sistémica en ratas lactantes por el ácido linoleico conjugado (CLA)
Cis-9, trans-11 (c9, t11) and trans-10, cis-12 (t10, c12) are the predominating molecules in the positional and geometrical isomers mixture termed CLA. Although CLA has shown positive effects on human health and seems to be associated with immunomodulatory activities, its effect in the developing immune system has not been studied. Thus, the present study was designed to establish the effect of CLA supplementation during gestation and/or lactation on humoral immune response, i.e. by analysing sera Ig levels during the suckling period. Wistar rats were allocated to four groups (A, B, C and W) on day 7 of pregnancy. From day 7 and throughout the study period group C and W gestating mothers were fed standard pellet chow. Group A and B dams were fed 10 g CLA (80% cis-9, trans-11, 20% trans-10, cis-12; Lipid Nutrition B. V. Wormerveer, The Netherlands)/kg pellet chow during gestation. Moreover, group A mothers were also fed the CLA-supplemented chow until the litters were 21 d old, the end of suckling period. Group B and C litters received the CLA mixture of isomers by daily oral administration while their respective dams were fed standard pellet chow during lactation. In all cases litters were equalised to ten rats per lactating mother. Pups from each experimental group were killed at the end of the second week of life (day 14) and at the end of the suckling period (day 21), and blood samples were collected. Serum IgA, IgG and IgM levels were quantified by the ELISA sandwich technique. ANOVA and post hoc comparisons (LSD test) were performed. Differences were considered to be significant at P<0.05. Animals receiving CLA passively from their mothers (group A) during gestation and the suckling period exhibited the highest concentrations of IgG and IgM at 14 d old (P<0.05; see Table). At the end of suckling period the serum IgG concentration in this group was also increased, up to three times more than in the other groups (P<0.05). Those animals supplemented with CLA only during suckling period (group C) showed no difference in relation to those receiving no supplement. Thus, these results demonstrate that CLA supplementation during gestation and lactation promotes systemic humoral immune response
Efecto de la aplicación de campos eléctricos sobre las interacciones entre los iones cloruro y la matriz de cemento
La determinación de coeficientes de difusión de los iones cloruro a través del hormigón precisa en muchas ocasiones de la aplicación de campos eléctricos con el fin de obtener resultados en plazos razonables de tiempo. Sin embargo, esta aceleración del transporte podría modificar las complejas interacciones que tienen lugar entre los iones cloruro y la matriz de cemento, haciendo que los coeficientes obtenidos mediante ensayos de migración no fueran representativos de condiciones de difusión natural. Este aspecto se aborda en el presente trabajo mediante la realización de ensayos de migración de cloruros en estado estacionario y no estacionario, así como de difusión natural de cloruros y oxígeno en estado estacionario. Como resultado, se ha podido establecer que cuando el transporte se produce por migración, hasta un campo aplicado de 10.5 V/cm, ésta tiene lugar a través de poros del mismo tamaño que por los que se lleva a cabo la difusión natural, produciéndose una interacción más débil del adsorbato con el sustrato que en difusión natural, lo que debe tenerse en cuenta a la hora de diseñar los ensayos de migración para la determinación de los coeficientes de difusión de cloruros en estado no estacionario. 
Cocoa diet diminishes the anti-collagen humoral response in collagen-induced arthritis in rats
Determination of the OH content in the aqueous phase of hardened cementitious materials by an empirical leaching method
The most reliable method to determine the concentration of hydroxyl ions in the aqueous phase of hardened cementitious materials is the squeezing of concrete at high pressures. However, this method needs special equipment as well as a relatively high amount of sample to be carried out. In present research, the determination of the OH concentration in the concrete pore solution is undertaken by a leaching method in granulated samples. The experimental program has been made using mortars with 5 different binders and three different leaching solutions. In the treatment of the results, different phenomena (dilution + dissolution of solid phases) occurring during leaching have been taken into account until reaching the target values validated by comparison with those obtained by means of the high pressure technique. The agreement found is good enough, for every binder tested, in spite of the fact that fully understanding of the leaching mechanism is not achieved and that concentrations and not activities of the ions are taken into account in the calculations. Therefore, the method suggested is empirical at present stage.  
Metodología para la intervención en elementos históricos: el caso de la espadaña del convento de Nuestra Señora de la Consolación (Alcalá de Henares-Madrid-España)
The purpose of this paper is the study of damage detected in the belfry of the convent of “Nuestra Señora de la Consolación”, Alcalá de Henares, as well as the materials analysis to establish both the current state of the structure as the nature and extent of the deterioration of the original materials. For a good detection of defects in the structure were the application of a methodology of previous studies in historical buildings, in which were used, among other techniques, the element Thermographic Analysis, to then proceed to the experimental determination of the emissivities of the different inspected materials. The use of supplementary techniques of analysis as porosimetry of mercury, x-ray diffraction, electron microscopy of scanning and thermogravimetry, as well as mechanical characterization of materials, has made it possible to delve into the characteristics of the Union mortar and employed; evaluate comprehensively current degradation status and facilitating the rehabilitation.El objeto del presente trabajo es el estudio de daños detectados en la espadaña del Convento de Nuestra Señora de la Consolación, Alcalá de Henares, así como el análisis de los materiales para establecer, tanto el estado actual de la estructura, como la naturaleza y grado de deterioro de los materiales originales. Para ello se aplicó una metodología de estudios previos en edificaciones históricas, en la que se utilizaron, entre otras técnicas, el análisis termográfico del elemento, para posteriormente proceder a la determinación experimental de las emisividades de los diferentes materiales inspeccionados. El uso de técnicas complementarias de caracterización y análisis como porosimetría de intrusión de mercurio, difracción de rayos X, microscopía electrónica de barrido y termogravimetría, así como la caracterización mecánica de los materiales, ha permitido ahondar en las características del mortero de unión y las piezas de fábrica; evaluando completamente el estado actual y facilitando su rehabilitación
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