VictorJuiz/thesis huggingface dataset:
Only Time Will Tell: Time-of-Day and the Cognitive Neuroscience of Executive Control in Aging

This thesis investigated whether testing older adults at their optimal time of day (the morning) would allow them to recruit similar neural resources to younger adults while performing a working memory task requiring inhibitory control. Chapter 1 explored whether older adults tested in the afternoon, but not the morning would have a difference in task-evoked BOLD signal from younger adults. Chapters 2 and 3 expand upon these results by exploring functional connectivity and BOLD frequency changes respectively. In Chapter 1 fMRI was used to expand behavioural findings that older adults perform best in the morning. During an fMRI scan scheduled early in the morning, or the afternoon older adults performed a 1-back task on pictures overlapped with irrelevant words, and were later given a fragment completion task that included words from the 1-back task. A young adult group was also scanned in the afternoon for comparison. Older adults tested in the morning were less distractible than peers tested in the afternoon, and critically, like young adults, were able to activate frontal and parietal regions that were correlated with better task performance. In Chapter 2 whole-brain functional connectivity during task was examined using graph-theory analysis. Previous studies have reported declines in older adults' functional connectivity. Studies using graph-theory have demonstrated age-related declines in network efficiency measures such as small-worldness and modularity. In the present data, older adults tested in the afternoon showed declines in network connectivity in line with previous findings from the literature while those tested in the morning were more similar to young adults. Finally, Chapter 3 examined how the frequency of the BOLD signal changed as a function of time of testing and age. Previous research has revealed that complexity of the BOLD signal is inadequately captured with the mean. Using fast fourier transform to decompose the BOLD signal for subsequent analysis with split half PLS (NPAIRS-PLS), we found age and time of day group differences in power across task, resting-state, and residualized vascular maps. Group differences were most pronounced during task. In sum, this thesis demonstrates that when people are tested impacts their performance on cognitive tasks and the neural substrates supporting these tasks - this is perhaps especially true for older adults, and as such, time of testing and circadian rhythms should be considered in studies of aging.

Keywords: Aging
Attention
Chronotype
Circadian
fMRI
Advisor: Grady, Cheryl L
Hasher, Lynn
Something for Everyone: Using Digital Methods to Make Physical Goods

In this dissertation I draw a link between the purported changes being wrought on society by the adoption of digital production technologies and previous waves of technological change in the production of goods. I use two case studies to provide detailed accounts of methods of production and development which use digital fabrication technologies to negotiate relationships between individuals and standards. The first case study, a collaborative Free/Libre Open Source Software development project, represents a kind of digital production which creates digital goods. The second case study looks at the digitally-aided fabrication of a physical good: 3D-printed sockets for prosthetic legs. I further argue that we need new frameworks for studying the intersection of the digital and the physical, or the inextricability of the two concepts. Scrutinizing the way mass methods of production almost always account for the needs of some kind of normative user, resulting in mis-fit for non-standard users, I then question arguments about mass-customization as a solution to mis-fit. One of the contentions I advance in this dissertation is that positioning mass production as necessarily harmful and marginalizing, while seeing mass customization as a solution, creates a counter-productive dichotomy. In service of that argument, I draw on historical work about a pre-digital custom industry: dressmakers in the pre- and early-Industrial period. Finally, I trouble the role of the user in production, and contend that, increasingly, the distinction is not between who is a user or a producer, but in which circumstances, and when, one is acting in the role of the user or producer.

Keywords: 3D printing
digital fabrication
digital goods
mass customization
open source software
standards
Advisor: Ratto, Matt
Assembly of Slx4 Checkpoint Signaling Complexes Behind Stressed DNA Replication Forks

Obstructions to replication fork progression, referred to collectively as DNA replication stress, challenge genome stability. In S. cerevisiae, cells lacking RTT107 or SLX4 show genome instability, sensitivity to DNA replication stress, and are defective in the completion of DNA replication during recovery from replication stress. I demonstrate that Slx4 is recruited to chromatin behind stressed replication forks, in a region that is spatially distinct from that occupied by the replication machinery. Slx4 complex formation is nucleated by Mec1 phosphorylation of histone H2A, which is recognized by the constitutive Slx4 binding partner Rtt107. Slx4 is essential for recruiting the Mec1 activator Dpb11 behind stressed replication forks, and Slx4 complexes are important for full activity of Mec1. I propose that Slx4 complexes promote robust checkpoint signaling by Mec1 by stably recruiting Dpb11 within a discrete domain behind the replication fork, during DNA replication stress.

Keywords: Checkpoint
ChIP-seq
Replication
Signaling
Slx4
Stress
Advisor: Brown, Grant W.
Should Network Meta-analysis Become the Standard in Evidence-based Clinical Practice?

Network Meta-analysis (NMA) is a statistical tool that allows comparing and estimating the relative effects of multiple interventions at the same time. Although its popularity has increased in the latest years, many questions remain unsolved before it can be proposed as the standard method of evidence synthesis for informing evidence clinical practice. In this thesis, using systematic surveys of the literature, we aimed to determine 1) the extent to which NMA can be used to answer current clinical questions; 2) whether systematic reviews (SRs) using NMA report the same results as SRs using head-to-head comparisons (HTHC); and 3) the robustness of the rankings obtained from NMA to the exclusion randomized clinical trials from the network, and the impact of increasing decision thresholds on the ranking probabilities. We observed that only 25.3% (205 out of 809 Cochrane SRs published in a 1-year period) of the SRs had questions in which an NMA was necessary; that SRs using NMA to assess the effects to stents in patients undergoing percutaneous coronary intervention reported the same results as SRs using HTHC in 44.8% to 83.3% of the cases; that rank probabilities and the rankings remain reasonably constant when excluding trials from the analysis (with an overall mean absolute change of 4.3% in rank probabilities across NMAs), but there are cases in which dramatic increases or decreases of the rank probabilities, and switches in the treatments ranked first and second can be observed; and that increasing the threshold to claim superiority may result in important changes in rank probabilities, which in some cases lead to the first treatment having extremely low probabilities of being distinguishable as the best. These issues suggest that because NMA is still in its infancy compared to HTHC, more research and guidance for its use are necessary before it can be claimed that NMA should become the standard for comparing treatment effectiveness.

Advisor: Tomlinson, George
Using Differential Item Functioning to Investigate the Impact of Reading Proficiency on Science Achievement

The most recent Standards for Educational and Psychological Testing emphasize the importance of maximizing the validity and reliability of an instrument by establishing its lack of measurement bias. This is often done through dimensionality analysis to ascertain the unidimensionality of the measured construct and through differential item functioning (DIF) to investigate whether a nuisance dimension may influence the items purported to measure a unidimensional trait. In this study, a combination of exploratory and confirmatory dimensionality analyses were used to guide a combination of exploratory and confirmatory DIF, differential bundle functioning (DBF) and crossing-DIF analyses to examine whether students' performance on a science assessment was adversely affected by reading comprehension as a nuisance dimension. DIMTEST was used to analyze the dimensionality of a test, whereas the standardization approach with SIBTEST was used to study differential item functioning. The analyses compared three language groups of interest in the Canadian context: French Minority, French Majority, and English students to examine whether groups of students with the same or with different levels of reading ability perform differently on science items and on science items with high reading demands. Using data from a sample of 32,000 Grade 8 students who wrote the 2013 Pan-Canadian Assessment Program (PCAP), the DIMTEST results on the science component suggested weak multidimensionality with the secondary dimension related to reading comprehension. The DIF analyses flagged many items advantaging the reference and focal groups in almost an equivalent proportion. When analyzing bundles of items related to specific aspects of the test specifications, the large number of significant paired comparisons was an indication of DIF cancellation and amplification which in most cases disadvantaged the English language students. The study demonstrated that a systematic approach to investigate dimensionality and DIF can contribute to the creation of a strong body of evidence supporting the fairness, equity, validity and reliability of inferences drawn from a test.

Keywords: Differential item functioning
dimensionality analysis
reading proficiency
science test
Advisor: Childs, Ruth A
Understanding Supportive Employment and Job Training in Canadian Social Purpose Enterprises: Drawing from Theories of Social Support

This thesis contains three papers that examine the socially supportive experiences of working at social purpose enterprises across Canada. The first paper presents a mixed-methods study exploring the range of work-centered social supports that can be part of the social purpose enterprise experience. From the perspective of managers and supervisors of these organizations, it explores the potential influence of these supports on the work outcomes and overall wellbeing of participants who often face significant and multiple barriers to employment. From the perspective of employees and job training participants, the second paper quantitatively examines the influences of practical and emotional social support on changes in participants' personal and vocational wellbeing during their time at the social purpose enterprises. Through participants' own personal accounts, the final paper explores the nature and meaning of their experiences of social support, both as provider and recipient of support. Findings from all three studies point to the importance of matching social support to the needs and goals of the employees and training participants, as well as the relevance of how people perceive their experiences of being supported in determining whether they actually benefit from the support. Presenting social purpose enterprises as vehicles for mobilizing social support through alternative work arrangements draws attention to the number of vulnerabilities faced by people most socially and economically excluded, of which employment is but one area requiring attention. This research contributes to a growing body of literature that demonstrates the holistic way these organizations can address issues of long-term employment exclusion as well as individual and community wellbeing more broadly.

Keywords: Employment
Nonprofit
Social purpose enterprise
Social support
Advisor: Quarter, Jack
The Social Investment State and the Social Economy. The Politics of Quebec's Social Economy Turn, 1996-2015

This dissertation argues that investigating the social economy is necessary to fully understand social investment politics and the specificity of the Quebec social model. Quebec has been structuring and promoting a social economy sector since the mid-1990s, launching social economy policies in areas such as child care, perinatal services, home support, social housing, and social insertion. No other provincial welfare state has taken a similar path. Why? Given their goal to address post-industrial social needs by increasing employment levels, Quebec’s social economy policies are here construed as social investment policies. Drawing from the comparative social investment literature and the Canadian federalism literature, I identify five hypotheses accounting for Quebec’s distinct trajectory: power resources, cross-class coalitions, learning, structural changes, and federalism. Using a process tracing methodology and relying on a variety of documentary sources and a unique data set of 77 interviews, I argue that the strength of Quebec’s Left in the mid-1990s, in combination with coalition engineering during the 1996 Economy and Employment Summit, are what chiefly account for Quebec’s social economy turn. The centre-Left PQ has proven to be significantly more committed to the social economy than the centre-Right PLQ. Moreover, it was actors from the Left, including the Quebec Women’s Federation and the CSN, who brought the issue of the social economy on the government’s agenda. The Social Economy Task Force, launched in prevision of the 1996 Summit, then skillfully engineered a Left-Right social economy coalition based on the idea that the social economy would infringe upon neither the public, nor the private sector, while creating jobs and addressing unmet social needs. The dissertation’s argument is nuanced, however. Although Quebec’s social economy policies were launched en bloc, they were not quite underpinned by exactly the same causes.

Advisor: Haddow, Rodney
Time-domain Modeling of Elastic and Acoustic Wave Propagation in Unbounded Media with Application to Metamaterials

Perfectly matched layers (PML) are a well-developed method for simulating wave propagation in unbounded media enabling the use of a reduced computational domain without having to worry about spurious boundary reflections. Many PML studies have been reported for both acoustic waves in fluids and elastic waves in solids. Nevertheless, further studies are needed for improvements in the fields of formulation, stability, and inhomogeneity of PMLs. This thesis introduces new second-order time-domain PML formulations for modeling mechanical wave propagation in unbounded solid, fluid, and coupled fluid-solid media. It also addresses certain stability issues, and demonstrates application of these formulations. Using a complex coordinate stretching approach a PML for the time-domain anisotropic elastic wave equation in two dimensional space is compactly formulated with two second- order equations along with only four auxiliary equations. This makes it smaller than existing formulations, thereby simplifying the problem and reducing the computational burden. A simple method is proposed for improving the stability of the discrete PML problem for a wide range of otherwise unstable anisotropic elastic media. Specifically, the value of the scaling parameter was increased thereby moving unstable modes out of the discretely resolved range of spatial frequencies. A new second-order time-domain PML formulation for fluid-solid heterogeneous media is presented. This formulation satisfies the interface coupling boundary conditions which were chosen such that they can be readily integrated into a weak formulation of the complete fluid-solid problem and which can be used in a finite element method (FEM) analysis. Numerical FEM results are given to establish the accuracy of the formulations and to provide examples of their application. In particular, numerical examples are shown to validate the elastic wave PML formulation and to illustrate the improved stability that can be achieved with certain anisotropic media that have known issues. In addition, the effectiveness of the fluid-solid PML is numerically demonstrated for absorbing all kinds of bulk waves, as well as surface and evanescent waves. Finally, the new formulations were used to predict the transient response of a solid phononic structure consisting of a superfocusing acoustic lens.

Advisor: Cobbold, Richard S. C.
Arc Minute

In astronomy, an arc minute is an angular measurement equal to 1/21600 of a circle. Arc Minute is a composition for orchestra (2 flutes, oboe, English horn, 2 clarinets in Bb, 2 bassoons, 4 Horns in F, 2 trumpets in C, percussion, piano and strings) of approximately eleven minutes in duration. It explores rhythmic and melodic fractals. The composition is largely monothematic, only occasionally deviating from a four-note motif and its various permutations. With a few exceptions, at least the contour of the motif and its inversion are strictly adhered to. Arc Minute also gives emphasis to establishing musical continuities through timbral manipulation. It takes advantage of timbral commonalities among the various instruments in the orchestra - especially percussion - and attempts to make their individual timbres organically evolve into each other. Additionally, the composition uses microtonal detuning that is anchored on a harp tuned to A4 = 428Hz. Careful attention is paid to use this instrument, along with some other ones capable of producing microtones, separately from the rest of the orchestra, as an echo reminiscent of the Doppler effect. This allows for unusual sonorities evoking imagery of phenomena extrinsic to music.

Keywords: Classical
Contemporary
Fractal
Music
Orchestral
Symphonic
Advisor: Hatzsis, Christos
The Diverse Geographies of Jewishness: Exploring the Intersections between Race, Religion, and Citizenship among Israeli Migrants in Toronto

In this dissertation, I explore how Jewish migrants who have relocated from Israel, but who are now living in the Greater Toronto Area understand, negotiate and perform their identities, belongings, and citizenship upon migration, both individually and collectively. Working from a series of forty-eight interviews and a set of participant observations at public events, I discuss how the discourses and material realities of life in Israel and in Toronto inform their attachments, identities, and claims of belonging. I illustrate the ways in which their hybrid and transnational identities, attachments, and claims of belonging challenge Euro-Zionism's homogenizing project - opening up potential for new revitalized spaces for conversations about Israel/Palestine. The empirical chapters in this study focus on the themes of diaspora, whiteness, and citizenship in an attempt to foreground the multi-dimensional and diverse nature of Jewish identity and Jewish multiculturality and multiraciality in Canada (and in Israel). Theoretically, this opens up opportunities to consider scaffolding that describes the complex multiplicity within cultures. Case studies are used to address the formation and re-formation of racial, religious, and national identities after migration, providing theoretical insights into the complex relations of multiple local racial formations to global racial formations, both historically and in the contemporary period, and their interconnectivity with other axes of difference, such as religion. In particular, I emphasize the intersection of racial formation and religious identity by foregrounding the immense diversity of Jewish identities, cultures, and racial connections. Doing so, I begin to map previously unexplored intersections between Jewish studies and critical theories of race in order to illuminate spaces for potential critical geographical analyses of these fields. This study, therefore, opens up new questions not only for future research on the "Israeli diaspora" , but also for studies of race, religion, migration, and urban space in social and cultural geography.

Keywords: Citizenship
Diaspora
Israel
Migration
Race
Religion
Advisor: Mahtani, Minelle
Leslie, Deborah
A Population Based Perspective of Children and Youth with Acquired Brain Injury in Ontario, Canada

Acquired brain injury (ABI) includes traumatic (TBI) and non-traumatic brain injury (nTBI). It is a leading cause of death and disability worldwide and can negatively affect the long-term development of children and youth living with an ABI. The objective of this thesis was to address current gaps in pediatric ABI research by (1) establishing the foundation for efforts to reach an appropriate case definition for pediatric TBI; (2) addressing the paucity of information on the health service use of children and youth with nTBI; and (3) expanding current knowledge on children and youth with a brain tumour by including data on individuals with metastatic and non-malignant brain tumours. Population based healthcare administrative data from Ontario, Canada, were used and children and youth with an ABI were identified using International Classification of Diseases Version 10 codes. Results showed that the number and rate, healthcare use, and intentional and mechanism of injury differed significantly when including/excluding 'unspecified injury to the head' diagnostic codes in the case definition for TBI, providing evidence for the importance of accurately interpreting current findings for the TBI population in reference to the case definition. Data also showed that although the rate of nTBI episodes of care was not as high as the rates reported for the TBI population, the health service use among the nTBI population was just as high as the TBI population. This suggests that the pediatric nTBI population puts an increased burden and demand on the healthcare system with currently little data to direct resources and planning. Finally, despite higher rates of malignant brain tumour episodes of care, patients with benign and unspecified brain tumours also use acute care and post-acute care services, indicating that current estimates for brain tumour and associated healthcare use are underestimates. This thesis provided a comprehensive update on children and youth with ABI from a population based perspective that has implications for policy and decision-making, health services planning, and resource allocation for ABI.

Keywords: Brain Injury
Brain Tumours
Health Services
International Classification of Diseases
Pediatrics
Advisor: Colantonio, Angela