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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A Case Study about the Efficiency of Therapeutic Painting Guidance Activities for Elementary Schools¡¦ Students with Emotional Disorders.

Fu, Chuan-fen 11 January 2005 (has links)
This study explores the moods and behavior of an emotionally impaired child before and after therapeutically oriented painting activities and assesses the effectiveness of this assistance method. The study employs qualitative research methods. The subject of this study is a fourth-grade emotionally impaired student who participated in painting activities twice each week, for a total of 16 sessions. Data was collected throughout the sessions via photography, audio and video recordings and analyzed for verbal descriptions, non-verbal expression, and interaction with the researchers. In addition, assessment, observation, and interviews of the student's mother and school personnel (administrators, guidance personnel, resource class teachers, guidance teachers, and class mothers) were used to gain an understanding of how effective therapeutically oriented painting activities are as a means of helping emotionally impaired children. This study reached the following conclusions from the research findings: (1) There was a significant improvement in the child¡¦s interpersonal relationships following the painting activities. (2) The child participated actively in family activities, and displayed positive interaction with his mother and older brother. (3) The child displayed significant positive changes in terms of innate abilities, learning motivation, self-affirmation, and personal growth. (4) The child's in-school performance displayed significant progress. (5) The child's communication abilities increased dramatically.
2

Modélisation mathématique de l'activité électrophysiologique des neurones auditifs primaires / Mathematical modeling of primary auditory neurons electrophysiological activity

Michel, Christophe 13 December 2012 (has links)
En réponse à une stimulation sonore, la cellule ciliée interne libère du glutamate qui va activer des récepteurs distribués sur le bouton post-synaptique. Les courants post-synaptiques vont ensuite dépolariser la terminaison périphérique des neurones auditifs primaires, et initier le déclenchement d'un potentiel d'action. Tandis que la connaissance des mécanismes pré-synaptiques a considérablement progressé ces 10 dernières années, les mécanismes responsables de l'initiation des potentiels d'action sont encore méconnus. Dans cette étude, nous avons déterminé les conductances ioniques nécessaires au déclenchement des potentiels d'action.Les paramètres biophysiques des conductances (Na+ et K+) ont été identifiés (algorithme d'identification trace entière) à partir d'enregistrements de patch clamp acquis sur les corps cellulaires. Un modèle mathématique de nœud de Ranvier a ensuite été développé en faisant l'hypothèse que les canaux présents sur le corps cellulaire et sur un nœud de Ranvier étaient de même nature mais en densité différente. Les paramètres de ce modèle ont été identifiés pour reproduire les potentiels d'action extracellulaire au moyen d'un algorithme de descente du gradient.Nous avons identifié : i) un courant Na+ entrant rapide (GNa activation: V1/2=-33 mV, tau_act< 0.5 ms; inactivation: V1/2=-61 mV, tau_inact < 2 ms) et deux courants K+ sortants, un rectifiant retardé activé à haut seuil (GKH, activation: V1/2=-41 mV; tau_act < 2.5 ms) et un activé à bas seuil (GKL, activation: V1/2=-56 mV; tau_act < 5 ms). Le modèle de nœud de Ranvier génère des potentiels d'action extracellulaire similaires à ceux enregistrés in vivo. La différence de durée du potentiel d'action observée le long de l'axe tonotopique (i.e. 450 µs de durée pic à pic à 1 kHz contre 250 µs à 20 kHz) s'explique parfaitement par un gradient de densité en canaux ioniques le long de la cochlée (GNa ~78 nS, GKL ~9 nS, GKH ~3 nS à 1 kHz contre GNa ~90 nS, GKL ~12 nS, GKH ~6 nS à 20 kHz).Cette étude a permis d'identifier les conductances ioniques et les densités de canaux responsables de l'initiation des potentiels d'action dans les neurones auditifs primaires. Elle suggère que la coopération entre le courant Na+ et des 2 courants K+ est probablement à l'origine de la haute fréquence de décharge de ces neurones. Le modèle de nœud de Ranvier permet en outre de tester de nouvelles stratégies de stimulation électrique dans le contexte de l'implant cochléaire. / In response to sound stimulation, inner hair cell triggers glutamate release onto the dendrite-like processes of primary auditory neurons and drives action potentials, which are convey to the central nervous system. Whereas knowledge of the transfer function at the ribbon synapse has considerably progress, little is known about the voltage-gated ionic channels which shape the action potential. Here, we provide a comprehensive computational model bridging the gap between the voltage-dependent currents measured in vitro on fresh isolated primary auditory neurons and spikes (extracellular action potentials) recorded in vivo from guinea pig auditory nerve fibers.Voltage-dependent currents (Na+ and K+) of SGNs somata patch-clamp recordings were fitted by a Hodgkin-Huxley model with a full trace identification algorithm. Node of Ranvier model was designed from the hypothesis that channel expressed on soma were identical, but differ in density. Simulated spikes were adjusted in order to match in vivo single-unit recordings with gradient-descent algorithm. Computation of the data allows to the identification of: i) one fast inward Na current (GNa activation: V1/2=-33 mV, τact< 0.5 ms; inactivation: V1/2=-61 mV, τinact < 2 ms); and ii) two K conductances, a high voltage-activated delayed-rectifier component (GKH, activation: V1/2=-41 mV; τact < 2.5 ms) and a low voltage-activated component (GKL, activation: V1/2=-56 mV; τact < 5 ms). Node of Ranvier model generate spikes that fit with in vivo recordings. Interestingly, the different spike durations along the tonotopic axis measured in vivo (i.e. 450 µs peak-to-peak duration versus 250 µs for 1 to 20 kHz, respectively) was explain by a gradual change in Na and K channel densities along the cochlea (GNa ~78 nS, GKL ~9 nS, GKH ~3 nS at 1 kHz versus GNa ~90 nS, GKL ~12 nS, GKH ~6 nS at 20 kHz).This study identifies the ionic conductances and densities, which shape the action potential waveform of auditory nerve fibers and suggests that the interplay of fast inward Na+ current and the two K+ enables the auditory nerve fibers to sustain high firing rates. In addition, this node of Ranvier model provides a valuable tool to design new electrical stimulation strategies for cochlear implants.

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