VictorJuiz/thesis huggingface dataset:
The Use of Dental Topographic Analysis in the Examination of Microsyopid (Mammalia, ?Primates) Evolution, Dietary Change, and Intraspecific Variation
Keywords: Dental
Microsyopids
Morphology
Plesiadapiforms
Topography

Plesiadapiforms are possible stem primates that first appear shortly after the extinction of the dinosaurs. One family of plesiadapiform, the Microsyopidae, is known from several thousand specimens from the early Eocene (approx. 55-52 million years ago) of the Southern Bighorn Basin, Wyoming. This dissertation uses a suite of methods called dental topographic analysis (DTA) to quantify functional aspects of microsyopid teeth. It also introduces a new method to study diet using variation in the frequency of dental caries.First, using DTA, I show that three early species of microsyopids (Arctodontomys wilsoni, A. nuptus, Microsyops angustidens) deriving from before, during, and after a localized cooling event, underwent dietary change leading up to and during this climatic event, associated only in part with taxonomic turnover. This expands on previous research suggesting that this event played a role in faunal turnover. In the second study, I focus on intraspecific variation in diet. Previously, DTA has been primarily used to study diet in extinct taxa at the interspecific level. The later occurring Microsyops latidens is known from over 1,000 specimens, and thus gives us an opportunity to iii look at finer scale variation in dental morphology (and therefore diet) over time. Although they lived during a period when local climate likely fluctuated, results suggest that diet remained relatively stable, pointing to the plasticity of this taxon, although a single specimen from a poorly sampled interval is suggestive of one brief period of change. Finally, M. latidens is characterized by a high prevalence of caries. Caries frequency suggests that the diet of M. latidens may not have been as stable as the overall dental topographic data suggest. There is a period during which caries frequency is much higher than expected in comparison to extant taxa, pointing to a temporary increase in the consumption of sugary foods in M. latidens, possibly associated with the outlier specimen in the DTA analysis. This chapter provides a framework for assessing caries in other fossil taxa. Overall, this dissertation provides new insights into the complex diet of microsyopids, a group for which little previous ecological information was known.
Feasibility of Using Transcranial Direct Current Stimulation to Improve Insight in Patients with Schizophrenia Spectrum Disorders
Keywords: Illness awareness
Insight into illness
MRI
Neuroimaging
Schizophrenia
tDCS

Impaired insight into illness is a common feature of schizophrenia that contributes to antipsychotic medication nonadherence and poor clinical outcomes. Currently, there are no established treatment options to improve insight in patients with schizophrenia. Common psychological interventions such as cognitive behavioural therapy and psychoeducation have shown limited effects on improving insight, indicating the need for alternative approaches. Here we explored the feasibility of using transcranial direct current stimulation (tDCS) to improve insight in patients with schizophrenia. First, we performed a systematic review and meta-analysis of randomized-sham controlled trials (RCT) to evaluate the clinical effects of tDCS in patients with schizophrenia. We showed that active compared to sham tDCS reduced the severity of auditory hallucinations and negative symptoms, but that the effects were more pronounced when ten or more sessions of tDCS were applied. Second, we examined the neuroimaging effects of tDCS on brain regions associated with impaired insight using task-based functional MRI and arterial spin labeling. We showed that bilateral tDCS to the parietal regions transiently modulated task-based brain activity and cerebral blood flow in the posterior parietal regions. Lastly, we examined the longitudinal relationship between impaired insight and antipsychotic medication nonadherence. We found that patients with impaired insight were more likely to show earlier nonadherence compared to patients with no or minimal impairment and that the rates of nonadherence in patients with impaired insight were significantly higher after 6 months of treatment initiation. Taken together, the results of this thesis work suggest that tDCS may be a feasible adjunctive treatment to improve insight in patients with schizophrenia. We also highlight the need to utilize intervention strategies early during treatment to improve or maintain insight and medication adherence in patients with schizophrenia.
Design and Applications of Biomimetic Nanofibrillar Hydrogels
Keywords: Cancer
Cellulose
Fibers
Hydrogels
Organoids
Polymers

Networks of nanofibers are ubiquitous in biological systems: the cellular cytoskeleton is composed of actin fibers, microtubules, and intermediate filaments, while the extracellular matrix (ECM) is made up of collagen, elastin, and fibronectin fibers. The filamentous architecture in these systems impacts biological processes and imparts the ECM and cytoskeleton with unique nonlinear mechanical properties. Nanofibrillar hydrogels that recapitulate the structure and nonlinear mechanical properties of these biological nanofiber networks have tremendous potential for applications in tissue engineering and three-dimensional cell culture. My thesis is focused on using rod-shaped cellulose nanocrystal (CNCs) as building blocks for nanofibrillar hydrogels. I first present two approaches for preparing CNC-based hydrogels: (1) by grafting thermoresponsive gelling polymers to the CNC surface, or (2) by mixing aldehyde functionalized CNCs with a crosslinking polymer (gelatin). The second approach, CNCs crosslinked with gelatin, produced a biocompatible fibrillar hydrogel named EKGel that had a precisely tunable structure, as well as a scalable and simple synthesis. Furthermore, I demonstrated that, because of its filamentous architecture, EKGel recapitulates the unique nonlinear mechanical properties of biological nanofiber networks. After establishing its ability to recapitulate the structure and properties of biological nanofiber networks, I explored several potential applications of EKGel. For example, through a microextrusion 3D-printing approach, EKGel can be used to prepare patterned structurally anisotropic hydrogel sheets for tissue engineering. Additionally, by modulating the composition of EKGel I was able to mimic the dynamic structural changes that occur in the ECM during tissue fibrosis, making EKGel an excellent matrix for in-vitro studies of fibrotic disease. I also describe the application of EKGel for the culture of patient-derived breast tumor organoids and demonstrate that EKGel is an improved alternative to the current gold-standard, BME. Finally, I describe the incorporation of EKGel into a microfluidic tumor spheroids-on-a-chip platform for drug screening.
Making Difficult Decisions: An Activity-theory Informed Qualitative Study of Shared Decision-Making for Children with Medical Complexity
Keywords: Child
Children with Medical Complexity
Parents
Pediatrics
Physician-Parent Communication
Shared Decision-Making

‘You are the expert when it comes to your child,’ is a common refrain heard by parents of children who frequently use healthcare. Parents are told that their ‘voice’ matters and that physicians want to work in partnership with parents to achieve the best for their children. At the same time, parents often express concern with being excluded from important discussions around the care of their child and feel that their concerns are not heard. The disparity between parental expectations and the reality of the healthcare experience, suggests that the willingness of physicians and parents to share the decision-making process may not be enough to ensure that a shared process unfolds. With a focus on children with medical complexity (CMC) who are frequent users of the healthcare system, this study aims to better understand the decision-making processes of those caring for CMC as a basis for developing solutions to improve the shared process. Taking a view of decision-making as a personal yet interconnected activity, we sought to understand the separate decision-making processes of the individual parties, parents of CMC, and the physicians treating CMC. With a better understanding of each party’s decision-making process, we then look at where the parent and physician decision-making processes have the potential to overlap and be shared. With the aim of developing an adaptable and practical model of shared decision-making (SDM) for CMC, we draw on findings from our studies on the individual processes of decision-making, build on existing models of shared decision-making and suggest a new model for SDM. The new model of SDM for CMC proposed as a result of this study reimagines shared decision-making as more than simply the exchange of information between the two parties. Our model considers how to best depict an SDM process that emphasizes the sharing of context within a limited scope, supports the family’s understanding, and is oriented towards achieving the family’s goal of coming to a decision with which they are comfortable.
Parkdale Infant Nutrition Security Targeted Evaluation Project (PINSTEP): Formative Research
Keywords: breastfeeding
breastfeeding support
Canada Prenatal Nutrition Program
infant and child nutrition
infant feeding

Background: Socially and/or economically vulnerable women in Canada have lower rates of breastfeeding. Skilled lactation support is one key strategy for improving practices, but it is less accessible to vulnerable women. The Canada Prenatal Nutrition Program (CPNP) aims to support breastfeeding among vulnerable women, but investigation of the potential to integrate postnatal lactation support has not been explored. Objectives: Formative research was conducted with participants at one Toronto CPNP site with separately funded postnatal lactation support services to determine (1) maternal sociodemographic/psychosocial characteristics and their association with CPNP participation; (2) experiences with breastfeeding and the lactation support program (in-home lactation consultant visits, breast pumps); (3) utilization of the lactation support program, infant feeding practices, and associations between maternal sociodemographics and six-month breastfeeding practices. Methods: (1) retrospective chart review of registered clients from 2013-2016 (n=339); (2) focus groups and interviews with 46 clients; (3) prospective cohort study collecting infant feeding data to six months postpartum (n=199). Results: CPNP clients at this site demonstrated a variety of vulnerabilities (e.g. 80% were born outside of Canada, 65% had incomes below the Low-Income Cut-Off), with few differences in CPNP participation based on maternal characteristics. Qualitative participants reported that the lactation support program helped to mitigate some physical, practical, and self-efficacy breastfeeding challenges. The most valued elements were the in-home services delivered by skilled, non-judgmental providers. Seventy-five percent of prospective cohort study participants received at least one lactation consultant visit. All participants initiated breastfeeding, 84% continued for six months, and 16% exclusively breastfed for six months. In univariate analyses, food insecurity was associated with lower rates of any breastfeeding at six months (p=0.014) and ≤ high school education with lower exclusive breastfeeding for six months (p=0.034). Conclusions: Results indicate that this CPNP site serves vulnerable women, their lactation support program is well-accepted and utilized, and a high proportion of women continued breastfeeding to six months. Mixed methods implementation research is needed to evaluate the effectiveness and feasibility of delivering postnatal lactation support within other CPNP sites across Canada and further investigation of preceding and contextual barriers to breastfeeding, such as food insecurity, is required.
Voice Your Values, a Tailored Advance Care Planning Intervention in Persons Living with Early Dementia: A Pilot Study
Keywords: Advance care planning
Aging
Dementia
Palliative approach
Pilot study
Primary care providers

A palliative approach to care aims to meet the needs of patients and caregivers throughout the trajectory of a chronic disease, such as dementia, and can be delivered by clinicians who are not specialists in palliative care. Advance care planning (ACP) is an important component of the palliative approach. Timely ACP can improve outcomes for persons living with dementia (PLwD) and their care partners. Yet only a minority of PLwD participate in any ACP discussions. There remains a lack of evidence-based guidelines to inform clinical practice, specifically related to ACP for those living with early dementia. To address this gap, an intervention called Voice Your Values (VYV) was developed, that healthcare professionals can implement to identify and document the values and wishes of PLwD for their future care. The tailored VYV intervention was evaluated using a single group pre-test and post-test design to determine its feasibility, acceptability, and preliminary efficacy. A convenience sample of 21 dyads of PLwD and their trusted individuals, such as family and friends, was recruited from five geriatric clinics in Ontario. The VYV intervention was delivered to dyads over two sessions using a secure videoconferencing platform. The recruitment rate was lower (52%) than expected (60%); however, the retention rate was high at 94%, and 100% of the participants rated VYV as highly acceptable. The PLwD demonstrated improvement in ACP engagement (p=.00). The trusted individuals showed improvement in decision-making confidence (p=.01) and psychological distress (p=.02), but no improvement in dementia knowledge (p=.22). The video and sound quality were rated highly. All PLwD were able to articulate and document their values and wishes related to terminal and vegetative states. The VYV study experienced some difficulties with recruitment. As well, some intervention sessions took longer than expected to deliver, highlighting the need for ACP conversations and the high level of engagement from participants, but also raising concern about the practicality of such lengthy conversations in actual clinical settings with limited resources. That said, the study demonstrated a high retention rate, intervention fidelity, and acceptability. Future studies are needed to further refine the VYV intervention and establish its efficacy using randomization and larger sample sizes.
“No one can decide for us…the solutions are within us”: Rhetoric and Reality of Youth Participation and Power in Sexual and Reproductive Health Decision-making in Malawi
Keywords: Decision-making
Focused critical ethnography
Lived citizenship
Malawi
Sexual and reproductive health
Youth participation

Ensuring active and meaningful participation of youth in decisions that affect their health and wellbeing has been recognized increasingly by the global health community as a critical strategy to meet young people’s unique sexual and reproductive health needs and rights. Despite aspirational global and national rhetoric promoting youth engagement and sexual and reproductive health (SRH), there is a dearth of scholarship on young people’s everyday realities of participating in SRH decision-making. This critical qualitative study, conducted in Malawi, examined young people’s lived experiences of engaging in SRH decision-making and the underlying structural and societal forces shaping their active and meaningful participation therein. Informed by postcolonial feminist and difference-centred citizenship theories, this study adopts a focused critical ethnographic approach to challenge normative, gendered, racialized and adultist assumptions of young people’s engagement in SRH decision-making. Data was generated from October 2017 to May 2018, using: document analysis, moderate participant observation of SRH policy meetings/events, six focus group discussions with 46 young people, 30 semi-structured interviews and open-ended drawing exercises with youth, 32 semi-structured interviews with key informants (including national/district policymakers, community leaders, non-governmental and civil society organizations, and multi- and bilateral donors) and a reflexive fieldwork journal. Reflexive thematic analysis, and document and visual analyses were employed to produce an understanding of young people’s experiences of participation in SRH decision-making. Findings reveal that despite progressive youth and SRH policies in Malawi, and the establishment of youth participatory mechanisms, young people’s authentic engagement in SRH decision-making remains limited. This study generates insights into young people’s efforts to realize their SRH and participatory rights within a postcolonial context, gerontocratic structures, and policymaking processes dominated by foreign donors and national government. It also exposes the disconnect between the global discourse on youth participation, citizenship, gender equality, and young people’s political, cultural, economic and social realities in practice. The conceptualization of “youth lived SRH citizenship” acknowledges young people’s agency and everyday acts or practices of citizenship. By recognizing youth, including girls and young women, as ardent participants and agents of SRH change within their community and country, this study explores the underlying structural and societal determinants that impede youth from meeting their SRH and participatory rights.
Strengthening Families through Responsive Caregiving: How to Target and Design Programs to Achieve Impact at Scale
Keywords: family systems
network meta-analysis
professional development
program evaluation
responsive caregiving

Experiencing more responsive interactions with caregivers during early development is associated with better mental well-being, physical health, educational attainment, and employment outcomes over the life course. Programs that support caregivers to provide more responsive care to young children improve both parenting practices and child outcomes; nonetheless, these programs and their benefits currently only reach a small fraction of families. This dissertation uses three empirical studies to identify possible targets, teaching strategies, and approaches to program delivery that can be leveraged to increase the effectiveness, efficiency, and reach of such programs. A social relations analysis presented in study one underscores the important role parental responsivity and financial status play in shaping family interactions. Findings from study two—a network meta-analysis of 120 randomized trials—suggest that responsive caregiving programs are most effective when they give parents opportunities to observe models of responsive caregiving, have a narrow focus, use researchers as facilitators, and instruct parents to practice skills at home. Notably, effectiveness is no higher, on average, in programs that use individualized instruction, more sessions, home visits, or video-feedback. Finally, the results of a randomized controlled trial presented in study three demonstrate that it is both feasible and effective to provide online, professional development on responsive caregiving to practitioners working in remote, low-income settings. Together, these findings highlight ways to expand access to and impact of responsivity programs for parents and practitioners, as well as the importance of targeting such efforts towards equity-deserving groups to reduce intergenerational sources of inequality.
Intraspecific Shape Variation in the Bony Labyrinth
Keywords: aging
bony labyrinth
development
morphology
variation

Intraspecific shape variation of the Homo sapiens bony labyrinth, or inner ear, has been previously explored in relation to its association with body size, sexual dimorphism, and genetic between-group differences. While studies of the influence of extrinsic and lifelong factors on labyrinthine shape variation have received less attention, they have the potential to further our understanding of functional and non-functional shape differences between the labyrinths of recent humans and our close relatives, such as Neanderthals. Research presented here uses sliding semilandmarks and three-dimensional geometric morphometrics to quantify bony labyrinth shape in both humans and model organisms, for the purpose of assessing the impact of extrinsic and lifelong variables throughout ontogeny.The first chapter of this dissertation investigates the effect of maternal malnutrition on rats exposed to a protein restricted diet through gestation and suckling. No changes in either labyrinthine shape or levels of fluctuating asymmetry were identified, despite a significantly smaller body mass in the experimental group. The second chapter focuses on assessing the effect of climate and subsistence strategy on a global sample of 262 recent humans from archaeological and morgue collections. Climate and subsistence strategy were found to be associated with 7% of overall shape variation each, with temperature being the primary climate variable associated with climate-related labyrinthine shape variation. Finally, in the third chapter, the effect of estrogen- induced osteoporosis is explored with an ovariectomized rat sample. No shape differences were identified between the experimental and control group. Although the low-estrogen group did exhibit higher morphological disparity, this difference was not statistically significant. Overall, extrinsic and lifelong variables, while minimal, were found to have an impact on intraspecific bony labyrinth shape variation at several life stages. These sources of variation should be considered when assessing labyrinth functional and phylogenetic differences at the taxonomic level, particularly when comparing hominins. These findings also suggest that it is important to use representative, large, and geographically diverse recent Homo sapiens as comparative samples.