<p>The author retains copyright of this thesis. It must only be used for personal non-commercial research, education and study. It must not be used for any other purposes and may not be transmitted or shared with others without prior permission. For further terms on this licence: </p> <a href="https://rightsstatements.org/page/InC-EDU/1.0/?language=en">https://rightsstatements.org/page/InC-EDU/1.0/?language=en</a><p></p> <p>Contact your local institution's library to make a resource sharing request for this thesis.</p><p dir="ltr">Winner of the Mollie Holman Doctoral Medal for Excellence</p>