5 resultados para Shubnikov de Haas oscillations

em Brock University, Canada


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The new Physiotherapy and Occupational Therapy programmes, based in the Faculty of Health Sciences, McMaster University (Hamilton, Ontario) are unique. The teaching and learning philosophies utilized are based on learner-centred and selfdirected learning theories. The 1991 admissions process of these programmes attempted to select individuals who would make highly qualified professionals and who would have the necessary skills to complete such unique programmes. In order to: 1 . learn more about the concept of self-directed learning and its related characteristics in health care professionals; 2. examine the relationship between various student characteristics - personal, learner and those assessed during the admissions process - and final course grades, and 3. determine which, if any, smdent characteristics could be considered predictors for success in learner-centred programmes requiring self-directed learning skills, a correlational research design was developed and carried out. Thirty Occupational Therapy and thirty Physiotherapy smdents were asked to complete 2 instruments - a questionnaire developed by the author and the Oddi Continuing Learning Inventory (Oddi, 1986). Course grades and ratings of students during the admissions process were also obtained. Both questionnaires were examined for reliability, and factor analyses were conducted to determine construct validity. Data obtained from the questionnaires, course grades and student ratings (from the admissions process) were analyzed and compared using the Contingency Co-efficient, the Pearson's product-moment correlation co-efficient, and the multiple regression analysis model. The research findings demonstrated a positive relationship (as identified by Contingency Coefficient or Pearson r values) between various course grades and the following personal and learner characteristics: field of smdy of highest level of education achieved, level of education achieved, sex, marital stams, motivation for completing the programmes, reasons for eru-oling in the programmes, decision to enrol in the programmes, employment history, preferred learning style, strong selfconcept and the identification of various components of the concept of self-directed learning. In most cases, the relationships were significant to the 0.01 or 0.(X)1 levels. Results of the multiple regression analyses demonstrated that several learner and admissions characteristic variables had R^ values that accounted for the largest proportion of the variance in several dependent variables. Thus, these variables could be considered predictors for success. The learner characteristics included: level of education and strong self-concept. The admissions characteristics included: ability to evaluate strengths, ability to give feedback, curiosity and creativity, and communication skills. It is recommended that research continue to be conducted to substantiate the relationships found between course grades and characteristic variables in more diverse populations. "Success in self-directed programmes" from the learner's perspective should also be investigated. The Oddi Continuing Learning Inventory should continue to be researched. Further research may lead to refinement or further development of the instrument, and may provide further insight into self-directed learner attributes. The concept of self-directed learning continues to be incorporated into educational programmes, and thus should continue to be explored.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

To investigate the thennal effects of latent heat in hydrothennal settings, an extension was made to the existing finite-element numerical modelling software, Aquarius. The latent heat algorithm was validated using a series of column models, which analysed the effects of penneability (flow rate), thennal gradient, and position along the two-phase curve (pressure). Increasing the flow rate and pressure increases displacement of the liquid-steam boundary from an initial position detennined without accounting for latent heat while increasing the thennal gradient decreases that displacement. Application to a regional scale model of a caldera-hosted hydrothennal system based on a representative suite of calderas (e.g., Yellowstone, Creede, Valles Grande) led to oscillations in the model solution. Oscillations can be reduced or eliminated by mesh refinement, which requires greater computation effort. Results indicate that latent heat should be accounted for to accurately model phase change conditions in hydrothennal settings.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Accuracy at reporting a second-target (T2) is reduced if it is presented within approximately 500 ms of the first target (T1) – an attentional blink (AB). Early models explained the AB in terms of attentional limitations creating a processing bottleneck such that T2 processing would be impaired while T1 processing was ongoing. Theoretical models of the AB have more recently been expanded to include the role of cognitive control. In this dissertation I propose that cognitive control, defined as the optimization of information processing in order to achieve goals, is maladapted to the dual-task conditions of the AB task in that cognitive control optimizes the T1 goal, due to its temporal proximity, at the cost of T2. I start with the concept that the role of cognitive control is to serve goals, and that how goals are conceived of and the degree of motivation associated with those goals will determine whether cognitive control will create the condition that cause the AB. This leads to the hypothesis that electrophysiological measures of cognitive control and the degree of attentional investment resulting from cognitive control modulate the AB and explain individual differences in the AB. In a series of four studies feedback-related N2 amplitude, (reflecting individual differences in the strength of cognitive control), and event-related and resting alpha frequency oscillatory activity (reflecting degree of attentional investment), are used to explain both intra- and inter-individual variability in performance on the AB task. Results supported the hypothesis that stronger cognitive control and greater attentional investment are associated with larger AB magnitudes. Attentional investment, as measured by alpha frequency oscillations, and cognitive control, as measured by the feedback-related N2, did not relate to each other as hypothesized. It is proposed that instead of a measure of attentional investment alone, alpha frequency oscillatory activity actually reflects control over information processing over time, in other words the timing of attention. With this conceptualization, various aspects of cognitive control, either related to the management of goals (feedback-related N2) or the management of attention over time to meet goals, explain variability in the AB.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This study used three Oculomotor Delayed Response (ODR) tasks to investigate the unique cognitive demands during the delay period. Changes in alpha power were used to index cognitive efforts during the delay period. Continuous EEGs from 25 healthy young adults (18-34 years) were recorded using dense electrode array. The data was analyzed by 6-cycle Morlet wavelet decompositions in the frequency range of 2-30 Hz to create time- frequency decompositions for four midline electrode sites. The 99% confidence intervals using the bootstrapped 20% trimmed mean of the 10 Hz frequency were used to examine the differences among conditions. Compared to two Memory conditions (Match and Non-Match), Control condition yielded significant differences in all frequencies over the entire trial period, suggesting a cognitive state difference. Compared to Match condition, the Non–Match condition had lower alpha activity during the delay period at each midline electrode site reflecting the higher cognitive effort required.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A price list for Lawrence A. Wilson Co. Limited, 87 James St., Montreal Quebec. It is addressed to The Toronto Hunt, 52 Bay Street, Toronto. There are additional handwritten notes. One of the handwritten notes reads "ck to W. Stephen Haas"