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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.
11

The validation of a task-specific measure of parenting self-efficacy for use with mothers of young children

Harty, Michal 17 October 2009 (has links)
This research develops and validates a task-specific parenting self-efficacy measure focussing on the following domains: showing affection and empathy, engaging in play, facilitating routines, establishing discipline strategies, providing appropriate learning and development activities, and promoting communication interaction. Self-efficacy can be described as a person’s belief in his or her ability to successfully complete tasks. Self-efficacy beliefs are among the most consistent predictors of success and performance in many contexts. As a result, self-efficacy has been investigated across a variety of domains. Parenting self-efficacy can be defined as judgement which a parent has regarding his or her ability to successfully complete the tasks related to parenting a child. Increasing parents’ competence in raising and supporting their children throughout life is regarded as one of the cornerstones of adaptive parenting. As improving parenting self-efficacy has been known to have a positive effect on parenting competence it has been incorporated as a component of early childhood intervention programmes in recent years. Numerous self-efficacy instruments are currently being used to measure self-efficacy within the parenting literature. In the development of this particular measure, challenges surrounding the conceptualization and operationalization of parenting self-efficacy have been investigated. The parenting sense of efficacy instrument (P-SEMI) was developed from theoretical frameworks within both parenting and self-efficacy domains. A classification for the definition and development of parenting self-efficacy measures is proposed. The relevant theoretical constructs are operationalized in order to identify their observable indicators (discrete parenting tasks). The main aim of this empirical research is therefore to validate the P-SEMI by establishing the internal consistency reliability, as well as face, content, construct, and differential validity for the measure. The design used is a descriptive survey type design with three phases. Phase 1 established validity in the conceptual domain. The measure was developed and content validity was investigated by a panel of subject matter experts. Phase 2 established validity in the methodological domain. During this phase the measure was administered to two groups of mothers; mothers of children with a disability, and mothers of typically developing children. Seventy-nine mothers participated in this phase of the study. Two additional established measures were used as convergent measures, namely the general self-efficacy scale (which is a global self-efficacy measure) and the parenting sense of competence scale (which is a domain-general measure). Based on the data collected from these participants, content, construct and differential validity was established. Phase 3 established initial validity in the substantive domain. Results indicated that the P-SEMI is a reliable and valid task-specific measure for assessing the level of parenting self-efficacy of mothers of young children. The P-SEMI is moderately correlated to both of the existing self-efficacy measures used as convergent measures. The newly developed task-specific measure was the only measure which was able to differentiate between the levels of parenting self-efficacy. As a result this measure is applicable as a clinical tool to measure parenting self-efficacy, and can be used to conduct further research within the field of parenting self-efficacy. / Thesis (PhD)--University of Pretoria, 2009. / Centre for Augmentative and Alternative Communication / unrestricted
12

A task-specific approach to job accommodation in physically-demanding positions

Bester, George Francis 29 October 2008 (has links)
Throughout the world, including South Africa, various approaches have been identified and implemented in an attempt to ensure that employees in physically-demanding positions are properly managed from a physical work capacity point of view, the primary goal always being to return the employee in need of assistance to full working capacity as soon as possible. The burning question has, however, always remained: “What happens to the employee in the meantime?” This study focused on exactly that question, the aim being to develop a comprehensive tool to assist all parties concerned in managing the affected employee through the application of task-specific job accommodation. The predetermined goal of the study was to develop a task-specific job accommodation tool for a physically-demanding position. This was achieved through a number of steps, which included an extensive literature review, a thorough job analysis, identification of a suitable test battery with related minimum physical requirements and cut scores, interviews, and the eventual development of the tool. Once the task-specific job accommodation tool was completed, the next step was to make use of three case studies to assist in illustrating the way the tool is to be implemented, as well as to show the potential value of its implementation. The information from three actual incapacity cases in the company concerned was used for these case studies. The results from this study are extremely positive and the three case studies have provided a glimpse of the potential value that could be added through the implementation of the job accommodation tool. The final product will greatly assist the company concerned in managing incapacitated employees in a manner that is beneficial to both the company and the individuals involved. Hopefully, this study will contribute to bring about a new era in the way South African companies and their occupational health departments approach the management of their incapacitated employees. Copyright 2008, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Bester, GF 2008, A task-specific approach to job accommodation in physically-demanding positions, DPhil thesis, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-10292008-180442 / > D498/gm / Thesis (DPhil)--University of Pretoria, 2008. / Biokinetics, Sport and Leisure Sciences / unrestricted
13

Sensorimotor behaviour in rats after lesions of dorsal spinal pathways

Kanagal, Srikanth Gopinath 05 September 2008
To investigate the roles of different dorsal spinal pathways in controlling movements in rats, I performed lesions of specific spinal pathways and measured the behaviour abilities of rats using different sensorimotor behavioural tests. The first experiment was designed to understand the contribution of sensory pathways traveling in the dorsal funiculus during locomotion and skilled movements using sensitive behavioural tests. I demonstrated that ascending sensory fibers play an important role during overground locomotion and contribute to skilled forelimb movements. The second experiment compared the differences in sensorimotor abilities caused by dorsal funicular lesions performed at two different levels of rat spinal cord. My results showed that the pathways present in the cervical and thoracic dorsal funiculus exert different functional effects over control of limb movement during locomotion. The third experiment investigated the compensatory potential of dorsal funicular pathways after dorsolateral funicular injuries in rats. My results showed that dorsal funicular pathways do not compensate for loss of dorsolateral pathways during the execution of locomotor tasks, though there is indirect evidence that rats with dorsolateral funicular lesions might rely more on ascending sensory pathways in the dorsolateral funiculus during skilled forelimb movements. Finally, the fourth experiment was designed to investigate the compensation from dorsolateral funicular pathways after injuries to pyramidal tract in rats. I demonstrated that pathways running in the spinal dorsolateral funiculus do provide compensatory input to spinal circuitry to maintain skilled reaching abilities after lesions of the pyramidal tract but these same pathways do not appear to compensate during either overground locomotion or skilled locomotion. Thus, this compensatory response is task-specific. These results highlight the fact that behavioural context determines the nature of compensation from spared pathways after spinal cord injuries.
14

Sensorimotor behaviour in rats after lesions of dorsal spinal pathways

Kanagal, Srikanth Gopinath 05 September 2008 (has links)
To investigate the roles of different dorsal spinal pathways in controlling movements in rats, I performed lesions of specific spinal pathways and measured the behaviour abilities of rats using different sensorimotor behavioural tests. The first experiment was designed to understand the contribution of sensory pathways traveling in the dorsal funiculus during locomotion and skilled movements using sensitive behavioural tests. I demonstrated that ascending sensory fibers play an important role during overground locomotion and contribute to skilled forelimb movements. The second experiment compared the differences in sensorimotor abilities caused by dorsal funicular lesions performed at two different levels of rat spinal cord. My results showed that the pathways present in the cervical and thoracic dorsal funiculus exert different functional effects over control of limb movement during locomotion. The third experiment investigated the compensatory potential of dorsal funicular pathways after dorsolateral funicular injuries in rats. My results showed that dorsal funicular pathways do not compensate for loss of dorsolateral pathways during the execution of locomotor tasks, though there is indirect evidence that rats with dorsolateral funicular lesions might rely more on ascending sensory pathways in the dorsolateral funiculus during skilled forelimb movements. Finally, the fourth experiment was designed to investigate the compensation from dorsolateral funicular pathways after injuries to pyramidal tract in rats. I demonstrated that pathways running in the spinal dorsolateral funiculus do provide compensatory input to spinal circuitry to maintain skilled reaching abilities after lesions of the pyramidal tract but these same pathways do not appear to compensate during either overground locomotion or skilled locomotion. Thus, this compensatory response is task-specific. These results highlight the fact that behavioural context determines the nature of compensation from spared pathways after spinal cord injuries.
15

Catalytic depolymerisation of starch-based industrial waste:use of non-conventional activation methods and novel reaction media

Hernoux-Villière, A. (Audrey) 10 June 2013 (has links)
Abstract The rapid increase of energy demand for transportation generates a rise of environmental pollution, stimulating the development of alternative sources of energy. Biomass is considered as the main organic carbon source of energy to substitute petroleum permitting sustainable production of chemicals and transportation fuels. Biowastes, residues and non-edible feedstock possess high potential resources avoiding food competition. This research aims to convert starch-based industrial waste, potato peels, into reducing sugars and platform molecules, such as glucose. These high added-value chemicals can further be transformed into chemicals and fuels. Catalytic conversion of starch, the main constituent of potato peels, was activated with non-conventional technologies to enhance the depolymerisation rate and to reduce energy consumption according to the principles of green chemistry. Depolymerisation of starch was first performed in acidic water as reaction medium assisted with ultrasonic and/or microwave irradiation. Ultrasonic irradiation enhanced mass transfer of heterogeneous system, whereas the use of microwaves improved heat transfer in the reaction medium. The frequency applied leads to different effects on heterogeneous systems: low frequencies irradiation (below 100 kHz) generates turbulences resulting in enhanced transport properties, whereas higher frequencies produce chemical effects. Catalytic conversion of starch into reducing sugars required more energy than individual irradiation could provide. Simultaneous irradiation, combining ultrasound and microwave or several ultrasonic frequencies, on potato peels led to 50% yield of sugars without former separation processes, at moderate temperature. A weak synergetic effect was only observed with potato peels. The second part of this research is dedicated to study the effect of catalytic reaction medium (acids, ionic liquids). More appropriate systems possess the ability to dissolve and hydrolyse carbohydrates: specific ionic liquids. A room-temperature ionic liquid and a task-specific ionic liquid were selected for their solvability properties to dissolve and depolymerise starch present in potato peels. The depolymerisation of starch in the task-specific ionic liquid generated a yield of 43% of sugars, without former separation process. / Tiivistelmä Liikenteen energiantarpeen nopea kasvu on johtanut päästöjen sekä ympäristösaasteiden lisääntymiseen. Biomassa on merkittävä raaka-ainevaihtoehto fossiiliselle hiilelle energian, kemikaalien ja liikenteen polttonesteiden tuotannossa. Erityisesti jätebiomassoilla on suuri merkitys biomassaraaka-aineena, koska ne eivät kilpaile ruoantuotannon kanssa. Väitöskirjatutkimuksen tavoitteena on tärkkelyspohjaisen teollisen jätteen, perunan kuorilietteen, katalyyttinen muuttaminen pelkistäviksi sokereiksi ja ns. platform-kemikaaleiksi, kuten glukoosiksi. Näistä korkean lisäarvon omaavista välituotteista voidaan edelleen valmistaa uusia biomassapohjaisia kemikaaleja ja polttoaineita. Tärkkelyksen, perunankuoren keskeisimmän aineosan, muuttaminen tehtiin tässä työssä mm. ultraääni- ja mikroaaltoavusteisella hajotuksella. Tavoitteena oli parantaa perunan kuorilietteen liukenemis- ja hajoamisnopeutta, lisätä saantoa sekä vähentää energian kulutusta vihreän kemian periaatteiden mukaisesti. Tärkkelyksen depolymerointi tehtiin ensin happokatalysoidussa liuoksessa ultraäänen ja/tai mikroaaltojen avulla. Ultraäänihajotus lisäsi aineensiirtoa heterogeenisessä reaktioväliaineessa, kun taas mikroaallot lisäsivät lämmönsiirtoa reaktioseoksessa. Eri ultraäänitaajuuksilla havaittiin olevan erilaisia vaikutuksia reaktioseokseen: alhaisilla taajuuksilla (alle 100 kHz) muodostuneet pyörteiset virtaukset edistivät aineensiirtoa ja korkeammat taajuudet kemiallisia ilmiöitä. Tärkkelyksen katalyyttinen depolymerointi vaatii enemmän energiaa kuin perinteisillä menetelmillä, kuten lämmittämällä, voidaan tuottaa. Yhdistämällä ultraäänen ja mikroaaltojen säteilytystä tai eri taajuuden omaavia ultraääniä, yli 50% perunajätteen tärkkelyksestä saadaan hajotettua pelkistyneiksi sokereiksi alhaisissa lämpötiloissa. Sen sijaan, ainoastaan perunankuorijätteellä havaittiin heikko synenerginen efekti mitä ei havaittu vertailunäytteellä (perunajauho). Toisena tavoitteena oli tutkia katalyyttisen reaktioseoksen (hapot, ioniset liuottimet) vaikutusta perunan kuorijätteen ja sen sisältämän tärkkelyksen liuottamiseen ja hajottamiseen. Erityisesti keskityttiin uusiin, spesifisiin ionisiin liuottimiin, jotka kykenevät samanaikaisesti sekä liuottamaan että hydrolysoimaan hiilihydraatteja. Huoneenlämpötilassa toimiva spesifinen ioninen liuotin valittiin sen katalyyttisten ominaisuuksien vuoksi. Tässä liuottimessa kuorilietteen sisältämästä tärkkelyksestä pelkistyneiden sokerien saanto oli 43%. / Résumé La forte demande en énergie, la conscience sociale sur les changements climatiques mondiaux et l'épuisement à moyen terme des réserves d’énergies fossiles stimulent le développement de ressources alternatives. Considérée comme la principale source de carbone organique renouvelable, la biomasse peut être utilisée pour remplacer les carburants d’origine fossile tout en étant plus respectueuse de l’environnement. Des déchets biosourcés ainsi que des végétaux d’origine agricole ou forestière, appelés biomasse végétale, possèdent de fort potentiels évitant la concurrence alimentaire. Cette recherche a pour objectif de convertir un déchet industriel amidonné, des pelures de pommes de terre, en sucres réducteurs et molécules plateformes, tels que le glucose, qui par la suite peuvent être transformées en carburants de transport. L’utilisation des ultrasons ainsi que des micro-ondes, méthodes non-conventionnelles, en milieu acide ont permis d’améliorer le rendement ainsi que de réduire la consommation énergétique en accord avec les principes de la chimie verte. L’irradiation ultrasonore améliore le transfert de masse de systèmes hétérogènes, alors que les micro-ondes renforcent le transfert de chaleur dans le milieu réactionnel. De plus, la fréquence ultrasonore appliquée induit différents effets sur le système : les ultrasons de basse fréquence (en dessous de 100 kHz) génèrent des turbulences améliorant les propriétés de transport de la matière, alors que les ultrasons de plus haute fréquence produisent des effets chimiques, tels que la formation de radicaux libres. L’apport énergétique fourni par les ultrasons et micro-ondes seuls étant insuffisant, l’utilisation d’irradiations simultanées et combinées a conduit à un rendement de 50% de sucres depuis l’amidon, ne nécessitant aucun procédé de séparation pré-réactionnel. Un faible effet synergique a pu être observé sur la dépolymérisation de la pelure de pommes de terre. L’étude d’un milieu réactionnel permettant simultanément la dissolution ainsi que l’hydrolyse des glucides présents dans la matière première est développée dans la seconde partie de ce mémoire. Certains liquides ioniques possèdent les propriétés recherchées. La dépolymérisation de l'amidon dans un liquide ionique à tâches spécifiques a permis d’obtenir un rendement de 43% de sucres, sans aucun procédé de séparation pré-réactionnel.
16

Epidemiologic Survey of a Unique Type of Task-Specific Dystonia in Brass Musicians

Wallace, Eric (Trombonist) 12 1900 (has links)
Brass musicians are known to experience a performance problem that is sometimes called valsalva maneuver or musical stuttering. This problem is known to cause difficulty starting a first note, tension in the throat, and tightness in the chest. Unfortunately, the research literature lacks sufficient details for evidence-based interventions. Therefore, the purpose of this study is to characterize and define this performance problem as experienced by brass musicians. An online epidemiologic survey was developed and deployed to collect data from brass musicians who have experienced this problem in their own playing. The survey was designed to acquire data in order to characterize and define the phenomenon through a biopsychosocial framework. The survey was also designed to assess whether this problem aligns with Altenmuller's heuristic model of motor control disruptions. A diverse group of brass musicians (n = 252) participated and offered relevant details for characterizing and defining this problem. Analysis of characteristic data suggests this problem is not a form of musical stuttering. Considering these data through Altenmuller's model suggests that this problem is experienced as a spectrum of motor disruptions that can develop into a unique type of musician's dystonia. While additional research is warranted, the results of this study are applicable to brass musicians, brass pedagogues, music educators, and performing arts health clinicians.

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