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Comparing Neuromuscular System Function In Healthy And Mobility-Impaired Older Females, Neal B. Mckinnon

Electronic Thesis and Dissertation Repository

Objectives: The objective of this thesis was to evaluate and compare neuromuscular system function in a group of young, healthy old and mobility-impaired older females (gait speed less than 1m/s) in an attempt to identify which neuromuscular factors contribute most to the loss of mobility and functional performance with age.

Methods: The ankle dorsiflexor and knee extensor muscles were used as a model in these studies. First, in Chapter 2 quantitative electromyography (EMG) was used to evaluate motor unit (MU) numbers, properties and the fidelity of the neuromuscular junction. Next, Chapter 3 conducted magnetic resonance imaging (MRI) to examine contractile …

Computational Unfolding Of The Human Hippocampus, Jordan M. K. Dekraker

Electronic Thesis and Dissertation Repository

The hippocampal subfields are defined by their unique cytoarchitectures, which many recent studies have tried to map to human in-vivo MRI because of their promise to further our understanding of hippocampal function, or its dysfunction in disease. However, recent anatomical literature has highlighted broad inter-individual variability in hippocampal morphology and subfield locations, much of which can be attributed to different folding configurations within hippocampal (or archicortical) tissue. Inspired in part by analogous surface-based neocortical analysis methods, the current thesis aimed to develop a standardized coordinate framework, or surface-based method, that respects the topology of all hippocampal folding configurations. I developed …

Neural Activity During Self-Referential Processing In Children At Risk For Depression., Pan Liu, Matthew R J Vandermeer, Marc F Joanisse, Deanna M Barch, David J A Dozois, Elizabeth P Hayden

Psychology Publications

BACKGROUND: According to cognitive theories of depression, more negative and less positive self-schemas are thought to play a causal role in the disorder. Existing evidence speaks to the neural substrates of self-referential processes in both healthy and depressed individuals, but little is known about how the brain relates to self-referential processing in the context of depression risk in children. We therefore studied the neural substrates of self-referential processing in never-depressed preadolescent children at high and low risk for depression based on maternal depression history.

METHODS: A total of 87 never-depressed 10-12-year-old children (29 with maternal depression) completed a self-referential encoding …

Osteochondritis Dissecans In Pediatric Patients With Juvenile Idiopathic Arthritis., Bradley C Jackson, Debra L Bartley, Roberta A Berard

Paediatrics Publications

No abstract provided.

Pulmonary Imaging Of Chronic Obstructive Pulmonary Disease Using Multi-Parametric Response Maps, Jonathan Macneil

Electronic Thesis and Dissertation Repository

Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow obstruction caused by airway remodelling and parenchymal destruction. Clinically, observation of COPD is performed using spirometry, but this technique only provides a global measure of lung health. To supplement these clinical measurements, thoracic computed tomography (CT) and hyperpolarized gas magnetic resonance imaging (MRI) have been used to measure regional structure and function abnormalities. Although CT and MRI have been used to research COPD, combination of both modalities into an interrelated image has never been performed. Therefore, we developed an image processing pipeline to combine MRI-CT information into a multi-parametric response …

A Randomized, Controlled Trial Of Alpha-Rhythm Eeg Neurofeedback In Posttraumatic Stress Disorder: A Preliminary Investigation Showing Evidence Of Decreased Ptsd Symptoms And Restored Default Mode And Salience Network Connectivity Using Fmri., Andrew A Nicholson, Tomas Ros, Maria Densmore, Paul A Frewen, Richard W J Neufeld, Jean Theberge, Rakesh Jetly, Ruth A Lanius

Department of Medicine Publications

OBJECTIVE: The default-mode network (DMN) and salience network (SN) have been shown to display altered connectivity in posttraumatic stress disorder (PTSD). Restoring aberrant connectivity within these networks with electroencephalogram neurofeedback (EEG-NFB) has been shown previously to be associated with acute decreases in symptoms. Here, we conducted a double-blind, sham-controlled randomized trial of alpha-rhythm EEG-NFB in participants with PTSD (n = 36) over 20-weeks. Our aim was to provide mechanistic evidence underlying clinical improvements by examining changes in network connectivity via fMRI.

METHODS: We randomly assigned participants with a primary diagnosis of PTSD to either the experimental group (n = 18) …