342 research outputs found

    Comparing tools for Service Quality Evaluation

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    Service quality evaluation is one of the main issues that have recently drawn managers' and researchers' attention. The definition of an evaluation standard not dependent on any particular service context has determined the popularity of many different quality tools. In this paper we show a comparative analysis of the affected tools that are widely used. These are summarized in an orientation map. Moreover we present some results of an experiment carried out with two of the major quality tools (SERVQUAL and QUALITOMETRO). The results identify good qualities as well as weaknesses for both tools. Possible improvement strategies are presente

    Sensitivity of the Wolf’s and Rosenstein’s Algorithms to Evaluate Local Dynamic Stability from Small Gait Data Sets: Response to Commentaries by Bruijn et al.

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    Assessing gait stability using the Largest Lyapunov Exponent (λ1) has become popular, especially because it may be a key measure in evaluating gait abnormalities in patient populations. However, clinical settings usually involve having small gait data sets and accurate determination of λ1 estimates from such sets is difficult. In an effort to address this issue, Cignetti et al.2 recently identified that λ1 estimates using the algorithm of Wolf et al.9 (W-algorithm) were more sensitive than those using the algorithm of Rosenstein et al.7 (R-algorithm) in order to capture age-related decline in gait stability from small data sets. Thus, they advocated the use of the former algorithm. Some concerns about the study were expressed afterwards by Bruijn et al.1 and we welcome the opportunity to discuss them in the present letter

    Complexity and Human Gait

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    Recently, the complexity of the human gait has become a topic of major interest within the field of human movement sciences. Indeed, while the complex fluctuations of the gait patterns were, for a long time, considered as resulting from random processes, the development of new techniques of analysis, so-called nonlinear techniques, has open new vistas for the understanding of such fluctuations. In particular, by connecting the notion of complexity to the one of chaos, new insights about gait adaptability, unhealthy states in gait and neural control of locomotion were provided. Through methods of evaluation of the complexity, experimental results obtained both with healthy and unhealthy subjects and theoretical models of gait complexity, this review discusses the tremendous progresses made about the understanding of the complexity in the human gait variability. Recientemente, la complejidad de la marcha humana se está convirtiendo en un tema de gran interés en el campo de la ciencia del movimiento humano. De hecho, mientras las fluctuaciones complejas de los patrones de la marcha fueron, durante mucho tiempo, consideradas como resultado de procesos al azar, el desarrollo de nuevas técnicas de análisis, las llamadas técnicas no lineales, ha abierto nuevas vías para el entendimiento de tales fluctuaciones. En particular, mediante la conexión de la noción de complejidad con la de caos, se están obteniendo nuevos conocimientos sobre la adaptabilidad de la marcha, las condiciones patológicas en la marcha y el control neural de la locomoción. Mediante métodos de evaluación de la complejidad, los resultados experimentales obtenidos tanto con individuos sanos como no sanos y con modelos teóricos de la complejidad de la marcha, esta revisión habla de los enormes progresos efectuados sobre el entendimiento de la complejidad en la variabilidad de la marcha humana

    Wearing a safety harness during treadmill walking influences lower extremity kinematics mainly through changes in ankle regularity and local stability

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    Background: Wearing a harness during treadmill walking ensures the subject’s safety and is common practice in biomedical engineering research. However, the extent to which such practice influences gait is unknown. This study investigated harness-related changes in gait patterns, as evaluated from lower extremity kinematics during treadmill walking. Findings: Healthy subjects (n = 10) walked on a treadmill at their preferred speed for 3 minutes with and without wearing a harness (LiteGait®, Mobility Research, Inc.). In the former condition, no weight support was provided to the subjects. Lower extremity kinematics was assessed in the sagittal plane from the mean (meanRoM), standard deviation (SDRoM) and coefficient of variation (CoVRoM) of the hip, knee, and ankle ranges of motion (RoM), as well as from the sample entropy (SampEn) and the largest Lyapunov exponent (LyE) of the joints’ angles. Wearing the harness increased the meanRoM of the hip, the SDRoM and the CoVRoM of the knee, and the SampEn and the LyE of the ankle. In particular, the harness effect sizes for both the SampEn and the LyE of the ankle were large, likely reflecting a meaningful decline in the neuromuscular stabilizing control of this joint. Conclusions: Wearing a harness during treadmill walking marginally influences lower extremity kinematics, resulting in more or less subtle changes in certain kinematic variables. However, in cases where differences in gait patterns would be expressed through modifications in these variables, having subjects walk with a harness may mask or reinforce such differences

    Executive function orchestrates regulation of task-relevant gait fluctuations

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    Humans apply a minimum intervention principle to regulate treadmill walking, rapidly correcting fluctuations in the task-relevant variable (step speed: SS) while ignoring fluctuations in the task-irrelevant variables (step time: ST; step length: SL). We examined whether the regulation of fluctuations in SS and not in ST and SL depends on high-level, executive function, processes. Young adults walked on a treadmill without a cognitive requirement and while performing the cognitive task of dichotic listening. SS fluctuations became less anti-persistent when performing dichotic listening, meaning that taxing executive function impaired the ability to rapidly correct speed deviations on subsequent steps. Conversely, performing dichotic listening had no effect on SL and ST persistent fluctuations. Findings suggest that high-level brain processes are involved only in regulating gait task-relevant variables

    Anterior-posterior and medial-lateral control of sway in infants during sitting acquisition does not become adult-like

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    We examined (1) how sitting postural control in infants develops in the anterior–posterior (A/P) and medial–lateral (M/L) directions of sway, and (2) whether this control is already adult-like during the late phase of infant\u27s sitting acquisition. COP data were acquired from 14 healthy infants (from the onset of sitting until independent sitting) and 21 healthy adults while sitting on a force platform. Attractor dimensionality (CoD: correlation dimension), attractor predictability (LyE: largest Lyapunov exponent), and sway variability (RMS: root-mean square) were calculated from the COP data to evaluate postural control. In the A/P direction, sitting was mastered by the infants by decreasing the active degrees of freedom of the postural system (decreased CoD), using a more predictable and (locally) stable sway (decreased LyE), and increasing sway variability (increased RMS). Control of sitting became practically simple, stable and exploratory with infant development. This may support the hypothesis that the sitting posture serves as the foundation for the development of other motor skills, as reaching. In the M/L direction, only sway variability decreased with development, possibly due to changes in the infant\u27s body dimensions. Taken together, these findings indicate that early in development the focus is more in the A/P than the M/L direction. Adults’ postural control was found more adaptable than the infants in both directions, involving more active degrees of freedom and less predictable sway patterns. Identifying the factors that make the dynamics of the postural system adult-like requires further research

    Las TIC como mediadoras en el proceso de escritura académica en inglés : Una experiencia innovadora

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    La enseñanza de la escritura ha sido beneficiada por la incorporación de las nuevas tecnologías. Fundamentalmente, éstas han ampliado las posibilidades de interacción y de colaboración entre los estudiantes y con los docentes. En este trabajo se presenta la experiencia de un taller de enseñanza de escritura académica en inglés dirigido a estudiantes de nivel de posgrado y docentes-investigadores de la Universidad Nacional del Litoral organizado en torno a un “Modelo de enseñanza y aprendizaje integrado” (García Aretio, 2004), en el cual se combina la enseñanza presencial y la virtual. El taller está organizado en cuatro encuentros presenciales y también se desarrolla de manera virtual a través de la plataforma educativa Moodle. En este espacio, los participantes cuentan con recursos que incluyen toda clase de materiales de referencia para completar sus actividades de escritura grupales, las que son entregadas a los docentes por esta vía para su revisión, retroalimentación y posterior reescritura. Este taller se viene llevando adelante con mucho éxito, lo cual se manifiesta en los avances en las producciones escritas de los participantes a medida que avanzan con el proceso de escritura y reescritura de cada una de las partes del artículo científico.Eje 4 - Mesa 5.Dirección de Educación a Distancia, Innovación en el aula y TI
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