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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

Haptic exploratory strategies and children who are blind with multiple disabilities

McLinden, Michael Timothy January 2000 (has links)
No description available.
2

Modelling Co-Occurring and Co-Varying Reported Health Behaviours: Applications of Machine Learning and Network Psychometrics

van Allen, Zachary 27 September 2023 (has links)
Background: Health behaviours play a central role in health status and quality of life, and engaging in behaviours such as physical inactivity, unhealthy eating, smoking tobacco, and alcohol use are leading risk factors for chronic disease. However, most literature in health psychology focuses on each health behaviour in isolation, whilst everyday life experience is characterized by engaging in multiple different behaviours. The proportions of Canadians engaging in multiple sub-optimal health impacting behaviours concurrently is not well understood, nor are the interactive relationships between multiple health behaviours and health outcomes. Moving from a single behaviour to a multiple behaviour paradigm can enable a new set of questions to be answered about which health behavioural combinations people tend to engage in, and what are the strengths and directions of associations between health behaviours, questions for which we do not yet have robust answers. This dissertation aimed to advance the basic science of 'multiple health behaviours' by examining the co-occurrence and covariation of health impacting behaviours. Methods: The thesis presents four studies that draw upon two large datasets: Studies 1, 2, and 3 use cross-sectional and longitudinal data (n = 40,268) from the Canadian Longitudinal Study of Aging (CLSA) while Study 3 and 4 use cross-sectional and longitudinal data from the international COVID-19 awareness, responses, and evaluation (iCARE) study (n = 85,861). Study 1 examines the co-occurrence of health impacting behaviours assessed with unsupervised machine learning methods, while Study 2 investigates the predictive utility of cluster analysis using multiple supervised machine learning methods. Study 3 investigates the interconnectedness of health behaviours, and their sociodemographic patterns, via network psychometrics (i.e., recursive partitioning-based network trees and network comparison tests) using cross-sectional data. Finally, Study 4 models the temporal associations between traditionally studied health behaviours and COVID-19 pandemic protective behaviours using temporal, contemporaneous, and between-subject network analysis. Results: Cluster analysis performed with data from the Canadian Longitudinal Study of Aging revealed seven groups of people based on similarity of behaviours (Study 1). These groups demonstrated sociodemographic variation but were not stronger predictors of health outcomes than individual behaviours. This pattern was consistent across several machine learning models (Study 2). Network psychometric analysis of national and international datasets explored correlations between health behaviours and revealed generally small associations with the exception of a larger relationship between physical activity and healthy diet, while the relationship between mask use and social distancing was stronger for males then women. (Study 3). The temporal dynamics of health behaviours (e.g., physical activity, alcohol consumption) and pandemic related health behaviours (e.g., hand washing, physical distancing) were modelled with items within the iCARE survey which identified bidirectional temporal effects between outdoor mask wearing and vaping behaviour as well as a temporal relationship between outdoor mask use and healthy eating (Study 4). Discussion: This dissertation aimed to advance the basic science of multiple health behaviours through an examination of the co-occurrence and co-variation of health impacting behaviours. Using cross-sectional and longitudinal data from the CLSA and the iCARE study, I identified seven clusters of commonly co-occurring health behaviours and their sociodemographic characteristics (Study 1), compared these clusters against individual behaviours for classifying and prediction health outcomes using machine learning (Study 2), explored the interconnectedness of traditionally studied behaviours and pandemic specific behaviours and identified sociodemographic patterning (Study 3), and modelled the temporal relationships between health behaviours over time during the Covid-19 pandemic (Study 4). In the multiple health behaviour change literature, it is assumed that health behaviours covary; however, findings from this dissertation call into question this assumption. Additionally, the lack of alignment between covariation and co-occurrence approaches for modelling the interconnectedness of health behaviours call into question the validity of cluster analysis for determining which behavioural combinations co-occur in the population. Before behavioural science can explain and predict health behaviour change, we must establish the basic science of multiple health behaviours.
3

The role of the DCMD neuron in triggering emergency avoidance reactions in locusts and robots

Santer, Roger D. January 2003 (has links)
No description available.
4

Narratives of geneticization : cystic fibrosis, diabetes and schizophrenia

Hedgecoe, Adam Michael January 2000 (has links)
No description available.
5

Investigations into the role of the GABAa α2-subunit containing receptors in anxiety, conditioning and behavioural responses to cocaine

Dixon, Claire Irene January 2008 (has links)
GABAa α2-subunit containing receptors are known to be expressed in brain regions associated with anxiety, conditioning and the rewarding properties of drugs of abuse, particularly the amygdala and nucleus accumbens (NAcc). Generation of a GABAa α2-subunit knockout mouse has enabled the role of this subunit to be investigated in these behaviours.
6

Essays on Health Economics, Health Behaviours, and Labour Outcomes

Bai, Yihong January 2023 (has links)
This thesis consists of three chapters that investigate issues related to health economics, health behaviours, and labour outcomes. Using the longitudinal data from the National Population Health Survey (NPHS), Chapter 1 examines the association between minimum wage increases and a wide range of health outcomes and behaviours, such as physical health, mental health, chronic conditions, unmet health need, obesity, insurance, smoking, drinking, food insecurity and fruit and vegetable consumption using Difference-in-Difference (DD) and Difference-in-Difference-in-Difference (DDD) models. There is no evidence that minimum wage increases are associated with most health outcomes and behaviours, including better health. There is an association for low-education females with a higher probability of reporting overall fair or poor health, and excess drinking but a lower probability of work absences due to illness and being physically inactive. For low-education men, there is an association with improved mental health and less drinking and smoking. Broadly there is more evidence that minimum wage increases lead to healthier behaviours than evidence of an actual improvement in health, perhaps because of lags effects that are not captured in this analysis. Chapter 2 links the survey data from 2015-16 Canadian Community Health Survey (CCHS) to job characteristics from O*Net to explore the role of job characteristics in explaining the positive association between drinking alcohol and income, which is commonly found in the literature. The study finds that controlling for job characteristics reduces “income return to drinking” substantially (by between one fifth and one half, depending on gender and the measure of alcohol consumption). Last, using data from the Ontario sample of the 2020 CCHS, Chapter 3 estimates the marginal effects of an index of social capital (at the individual or aggregated level) on changes in intentions to get vaccinated. Results show that individual-level social capital is associated with a greater willingness to get vaccinated against Covid-19 at all ages, while aggregate-level social capital is associated with higher vaccination willingness only among older adults. / Dissertation / Doctor of Philosophy (PhD)
7

Visual Inputs and Motor Outputs as Indivduals Walk Through Dynamically Changing Environments

Cinelli, Michael 24 August 2006 (has links)
Walking around in dynamically changing environments require the integration of three of our sensory systems: visual, vestibular, and kinesethic. Vision is the only modality of these three sensory systems that provides information at a distance for proactively controlling locomotion (Gibson, 1958). The visual system provides information about self-motion, about body position and body segments relative to one another and the environment, and environmental information at a distance (Patla, 1998). Gibson (1979) developed the idea that everyday behaviour is controlled by perception-action coupling between an action and some specific information picked up from the optic flow that is generated by that action. Such that visual perception guides the action required to navigate safely through an environment and the action in turn alters perception. The objective of my thesis was to determine how well perception and action are coupled when approaching and walking through moving doors with dynamically changing apertures. My first two studies were grouped together and here I found that as the level of threat increased, the parameters of control changed and not the controlling mechanism. The two dominant action control parameters observed were a change in approach velocity and a change in posture (i.e. shoulder rotation). These findings add to previous work done in this area using a similar set-up in virtual reality, where after much practice participants increased success rate by decreasing velocity prior to crossing the doors. In my third study I found that visual fixation patterns and action parameters were similar when the location of the aperture was predictable and when it was not. Previous work from other researchers has shown that vision and a subsequent action are tightly coupled with a latency of about 1second. I have found that vision only tightly couples action when a specific action is required and the threat of a collision increases. My findings also point in the same direction as previous work that has shown that individuals look where they are going. My last study was designed to determine if we go where we are looking. Here I found that action does follow vision but is only loosely correlated. The most important and common finding from all the studies is that at 2 seconds prior to crossing the moving doors (any type of movement) vision seems to have the most profound effect on action. At this time variability in action is significantly lower than at prior times. I believe that my findings will help to understand how individuals use vision to modify actions in order to avoid colliding with other people or other moving objects within the environment. And this knowledge will help elderly individuals to be better able to cope with walking in cluttered environments and avoid contacting other objects.
8

Visual Inputs and Motor Outputs as Indivduals Walk Through Dynamically Changing Environments

Cinelli, Michael 24 August 2006 (has links)
Walking around in dynamically changing environments require the integration of three of our sensory systems: visual, vestibular, and kinesethic. Vision is the only modality of these three sensory systems that provides information at a distance for proactively controlling locomotion (Gibson, 1958). The visual system provides information about self-motion, about body position and body segments relative to one another and the environment, and environmental information at a distance (Patla, 1998). Gibson (1979) developed the idea that everyday behaviour is controlled by perception-action coupling between an action and some specific information picked up from the optic flow that is generated by that action. Such that visual perception guides the action required to navigate safely through an environment and the action in turn alters perception. The objective of my thesis was to determine how well perception and action are coupled when approaching and walking through moving doors with dynamically changing apertures. My first two studies were grouped together and here I found that as the level of threat increased, the parameters of control changed and not the controlling mechanism. The two dominant action control parameters observed were a change in approach velocity and a change in posture (i.e. shoulder rotation). These findings add to previous work done in this area using a similar set-up in virtual reality, where after much practice participants increased success rate by decreasing velocity prior to crossing the doors. In my third study I found that visual fixation patterns and action parameters were similar when the location of the aperture was predictable and when it was not. Previous work from other researchers has shown that vision and a subsequent action are tightly coupled with a latency of about 1second. I have found that vision only tightly couples action when a specific action is required and the threat of a collision increases. My findings also point in the same direction as previous work that has shown that individuals look where they are going. My last study was designed to determine if we go where we are looking. Here I found that action does follow vision but is only loosely correlated. The most important and common finding from all the studies is that at 2 seconds prior to crossing the moving doors (any type of movement) vision seems to have the most profound effect on action. At this time variability in action is significantly lower than at prior times. I believe that my findings will help to understand how individuals use vision to modify actions in order to avoid colliding with other people or other moving objects within the environment. And this knowledge will help elderly individuals to be better able to cope with walking in cluttered environments and avoid contacting other objects.
9

Motivation and the information behaviours of online learning students: the case of a professionally-oriented, graduate program

Saumure, Kristie 11 1900 (has links)
Online learning is a wonderful opportunity for students who cannot attend classes at conventional times and places to further their education. However, to some extent, accessing and sharing information is often quite different and potentially more difficult for this particular group (e.g., they may lack access to the campus library). For this reason, it is important to appreciate both how the students are seeking and sharing information in this environment, as well as what drives these information behaviours. Understanding these processes will better enable instructors, librarians, and other relevant parties to facilitate information access to this population (e.g., through in-depth database training and/or better technology tools). With that in mind, this research asked: 1) In what types of information seeking and sharing behaviours do online learning students engage? 2) What motivates online learning students to both seek and share information? 3) Can a theoretical model of students motivational orientations as they apply to their information behaviours be developed? To answer these questions, the Teacher-Librarianship by Distance Learning Program was examined as an in-depth case study. A grounded theory approach was employed to enable the development of the motivational theory. Data were collected exclusively through in-depth, semi-structured interviews, though with two distinct groups of people: 15 students and 3 key informants. The students were asked to reflect on their experiences accessing and sharing information in the online setting as well as what they thought drove their information behaviours, while the key informants provided context around the program itself and offered their insights into how they believe the students interact with information. Overall, this study revealed that both electronic and local resources are key to these students information seeking successes. Furthermore, the results suggest that personally or professionally relevant assignments provide students with the greatest motivation to seek information for their coursework. Students in this online learning environment were inclined to share professional, academic, and personal information with others because they believed that this online learning environment fostered a culture of sharing.
10

Motivation and the information behaviours of online learning students: the case of a professionally-oriented, graduate program

Saumure, Kristie Unknown Date
No description available.

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