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The Role Of Fruitless P3 And P4 Transcripts In Drosophila Melanogaster, Sara A. Kulinski

Electronic Thesis and Dissertation Repository

The fruitless gene is highly conserved across many insect species, and its role in sex determination and sexual behaviour in Drosophila melanogaster males has been well characterized. The fruitless gene is alternatively spliced to produce at least 15 transcripts, but little is known about the alternative transcripts not involved in sexual traits. Transcripts beginning with the P3 and P4 first exons have previously been shown to be more heavily expressed during developmental stages of the D. melanogaster life cycle and have been implicated in developmental and fitness traits. Yet, these transcripts have never been assessed for their involvement in developmental …

Sufu In Shh Signalling Mediated Myogenesis, Suleyman Abdullah

Electronic Thesis and Dissertation Repository

Myogenesis is defined as the formation of skeletal muscle tissue during embryonic development and involves a multitude of cellular signalling pathways. Among these include the Sonic hedgehog (Shh) signalling pathway which must be deactivated for differentiation into muscle cells to occur. However, less is known regarding the pathways operation during cell differentiation and whether Suppressor of Fused (SUFU), the protein inhibitor of Shh signalling, plays a role. To address this, mouse C2C12 myoblast cells were utilized as a model and differentiated into muscle cells to identify the presence of SUFU during this time. Experiments in qRT-PCR show a decrease in …

Investigating Task-Free Functional Connectivity Patterns In Newborns Using Functional Near-Infrared Spectroscopy, Homa Vahidi

Electronic Thesis and Dissertation Repository

Robust functional connectivity in sensorimotor resting-state network (RSN) has been linked to positive neurodevelopmental outcomes in neonates. In the current study, we aimed to map the developmental trajectory of sensorimotor RSN in awake neonates using functional near-infrared spectroscopy (fNIRS). We acquired fNIRS resting-state data from 41 healthy newborns (17 females, gestational age range=36+0 to 42+1 weeks) within the first 48 hours after birth. At the group level, we observed robust positive connectivity in numerous channel-pairs across the sensorimotor network, especially in the left hemisphere. Next, we examined the relationship between functional connectivity, gestational age and postnatal age, while controlling for …

Water-Fat Magnetic Resonance Imaging For The Assessment Of Human Fetal Adipose Tissue, Stephanie A. Giza

Electronic Thesis and Dissertation Repository

Adipose tissue is crucial for providing heat and energy to infants, especially at transitions such as birth and therefore must begin developing in utero. This development may be altered due to an adverse uterine environment, increasing the risk of developing later-life metabolic diseases such as obesity. An early assessment of fetal adipose tissue development through lipid accumulation could be key to understanding metabolic programming and minimizing this risk.

Water-fat magnetic resonance imaging (MRI) can non-invasively measure the lipid concentration of tissues and can therefore monitor the development of adipose tissue via tissue lipid concentration. This work demonstrated the feasibility …

Examining The Relationships Between Socio-Cognitive Factors And Neural Synchrony During Movie Watching Across Development, Kathleen M. Lyons

Electronic Thesis and Dissertation Repository

While different cognitive abilities mature, the conscious experiences of children likely become richer and more elaborate. A challenge in investigating relationships between cognitive development and real-world experiences is having measures that assess naturalistic processing. Movie watching offers a solution, since following the plot of a film requires cognitive processes that are similar to real-world experiences. When different adults watch the same film, their brain activity begins to align (known as neural synchrony). The strength of this alignment has been shown to reflect the degree to which different individuals are having a similar experience of the movie. While this phenomenon has …

Developmental Differences In The Learning And Consolidation Of Linguistic Regularities, Sarah Berger

Electronic Thesis and Dissertation Repository

Relative to adults, children have a well-known advantage for learning linguistic regularities, which could be partially driven by their deeper sleep. To examine the relationship between consolidation and language learning across development, children and adults learned a novel article system with an implicit grammatical rule. Participants performed a judgment task on phrases containing the novel articles before and after a night of EEG-monitored sleep. We found that rule sensitivity emerged rapidly in children, whereas it did not emerge until the second session in adults. Children demonstrated better generalization of the rule than adults. Consolidation effects showed a developmental double dissociation, …

Dissolving Nature/Nurture: Development As Coupled Interaction, Derek E. Oswick

Electronic Thesis and Dissertation Repository

For many, the Nature/Nurture approach to development is a quaint figment of the past. We have moved on, one might think; everyone thinks that both categories are important for development, not merely one. The reality, however, is not so simple. In this dissertation, I argue that contemporary biology has not succeeded in getting out from under the shadow of Nature/Nurture, despite everyone being some sort of interactionist about development. The central aim of my project is to offer a form of developmental interactionism worth having, which succeeds in shedding the pernicious aspects of Nature/Nurture. I begin by giving an overview …

Spatiotemporal Characterization Of The Prr12 Paralogues In Zebrafish, Renee Jeannine Resendes

Electronic Thesis and Dissertation Repository

Pathogenic variants in the human PRR12 (Proline Rich 12) gene are associated with PRR12-related Neuroocular Syndrome. However, little is known about the gene/protein function. The zebrafish was utilized to address this, as its attributes place it as a premier model to study genes involved in human development and disease. In situ hybridization and RT-PCR of embryos and larvae, and qRT-PCR of adult tissues revealed the spatial and temporal distributions of the prr12 paralogues: prr12a and prr12b. Both paralogues were detected from the maternal and zygotic transcriptomes in a global and diffuse expression pattern, and there was enrichment …

Approaches To Examining The Role Of Auditory Evoked Potentials In Early Language Development, Alyssa Janes

Electronic Thesis and Dissertation Repository

Previous research has suggested a relationship between auditory evoked potentials (AEPs) and spoken language proficiency, but their interactions during the earliest stages of development are not well understood. AEP-Age, an index that estimates the maturity of a child’s AEP relative to same-aged peers, has been effective in investigating this relationship in school-aged children, but has yet to be applied to younger populations. This thesis includes two Stage 1 Manuscripts (Registered Reports) for future studies to (a) assess the utility of AEP-Age to predict chronological age and language ability in 18-48-month-old children, and (b) investigate the relationship between AEP-Age and …

Three Essays On Climate And Development, Samantha Goertz

Electronic Thesis and Dissertation Repository

My thesis studies the impact of weather shocks in developing countries. Each chapter of my thesis focuses on a different outcome variable that may be affected by weather shocks: migration, agricultural GDP, and education. The first two are analyzed in the context of Eastern Africa, with data from Kenya and Tanzania, and use data spanning several decades. The third studies a specific tropical storm in Guatemala using data for several years before and after the storm.

My first chapter addresses two questions: What is the inter-regional migration response to weather in Kenya and Tanzania? And does this response vary depending …

Validating An Observational Coding System For The Dominance Behavioural System (Dbs) In Childhood, Jennifer Mullen

Electronic Thesis and Dissertation Repository

The dominance behavioural system (DBS) is a biologically based system that underpins individual differences in motivation for dominance and power. However, little is known about the DBS in childhood. In a pilot study aimed at developing a behavioural coding system for dominance, a key facet of the DBS, we collected and coded observational data from 58 children, assessed at ages 3 and 5-6. Between these ages, dominance was moderately stable, to a degree comparable to other early child temperament traits. Consistent with study hypotheses, boys were more dominant than girls, and dominance was negatively associated with children’s behavioural inhibition, effortful …

The Role Of Xenopus Laevis Reck In Ecm Remodeling And Tissue Patterning, Jessica Willson

Electronic Thesis and Dissertation Repository

Proper cell-cell and cell-extracellular matrix (ECM) interactions are vital for cell migration and patterning of the vertebrate embryo. Matrix metalloproteinases (MMPs) and their inhibitors, reversion-inducing cysteine-rich proteins with Kazal motifs (RECK) and tissue inhibitors of metalloproteinases (TIMPs), are all differentially expressed during embryogenesis to regulate such ECM remodeling events and cell interactions. While TIMPs are a family of 4 secreted proteins that share overlapping substrate specificities of MMPs, RECK is unique in that it is a membrane-anchored MMP inhibitor that is embryonic lethal in mice. I used Xenopus laevis as a model organism to investigate the role of RECK as …

How Does The Brain Represent Digits? Investigating The Neural Correlates Of Symbolic Number Representation Using Fmri-Adaptation, Celia Goffin

Electronic Thesis and Dissertation Repository

How does the brain represent numerical symbols (e.g., Arabic digits)? Activity in left parietal regions correlates with symbolic number processing. Research with functional resonance imaging adaptation (fMRI-A) indicates that the intraparietal sulcus (IPS) exhibits a rebound (increase in activation) effect when a repeatedly presented number is followed by a new number. Importantly, this rebound effect is modulated by numerical ratio as well as the difference between presented numbers (distance). This ratio-dependent rebound effect could reflect a link between symbolic numerical representation and an approximate number system (ANS). In this doctoral dissertation, fMRI-A is used to investigate mechanisms underlying symbolic number …

The Origins And Development Of Visual Categorization, Laura Cabral

Electronic Thesis and Dissertation Repository

Forming categories is a core part of human cognition, allowing us to make quickly make inferences about our environment. This thesis investigated some of the major theoretical interpretations surrounding the neural basis of visual category development. In adults, there are category-selective regions (e.g. in ventral temporal cortex) and networks (which include regions outside traditional visual regions—e.g. the amygdala) that support visual categorization. While there has been extensive behavioural work investigating visual categorization in infants, the neural sequence of development remains poorly understood. Based on behavioral experiments, one view holds that infants are initially using subcortical structures to recognize faces. Indeed, …

Partial Characterization Of Putative Cyp86a Genes From Soybean, Trish Tully

Electronic Thesis and Dissertation Repository

Soybean (Glycine max [L.] Merr.) is a globally cultivated crop that is important to the sustainability of many industries. However, like all plants, optimal cultivation of soybean is threatened by detrimental environmental factors. For example, high yield of soybean is threatened by soil-borne pathogens like Phytophthora sojae. Resistance against P. sojae was previously positively correlated with aliphatic suberin deposition in soybean. As such, a deeper understanding of the biosynthesis of suberin may assist in engineering a resistant form of soybean, based on enhanced suberin content. In soybean, the ω-OH fatty acid monomers are predominant and most strongly correlated …

The Differentiation Of Smallholder Farming And Household Food Responsibilities In Northern Ghana, Siera Vercillo

Electronic Thesis and Dissertation Repository

One of the most urgent problems facing sub-Saharan Africa is that many people lack access to safe, nutritious, and culturally appropriate food, particularly in semi-arid regions such as northern Ghana. An important indication of this problem within Ghana is that stunting rates due to prolonged undernourishment are significantly higher in the northern regions than in other parts of the country, despite claims of an overall increase in the availability of food. Broadly, this dissertation employs qualitative case study research in the Northern Region (interviews N=109 and 12 focus groups) to describe the changes in access to resources, roles and …

A Comprehensive Catalog Of Post-Translational Modifications Of Drosophila Melanogaster Hox Protein, Sex Combs Reduced, Anirban Banerjee

Electronic Thesis and Dissertation Repository

During formation of the anterior-posterior axis, Homeotic selector (HOX) proteins determine the identity of Drosophila body segments. HOX proteins are transcription factors that regulate gene expression during development. Besides a highly conserved DNA-binding homeodomain (HD), HOX proteins also contain functionally important, evolutionarily conserved small motifs. These short motifs found in HOX proteins may be Short Linear Motifs (SLiMs). SLiMs are proposed to be sites of phosphorylation and this may regulate the activity of HOX proteins. The primary aim of this work was to develop a comprehensive catalogue of the sites of phosphorylation and other post-translational modifications (PTMs) for Fushi tarazu …

The Effects Of Early Adolescent Lipopolysaccharide Or Cat Odour Exposure Followed By Propionic Acid Administration On Anxiety, Startle Response, And Sensorimotor Gating In Adolescence And Adulthood, Deanne Tak On Wah

Electronic Thesis and Dissertation Repository

Autism spectrum disorders (ASD) are caused by genetic factors and a complex set of risk factors including early stressors and alterations in the gut microbiome. The present thesis investigated whether environmental stressors during early adolescence predisposes rats administered another stressor in later adolescence and adulthood to produce altered anxiety-like behaviours, startle response, and percent prepulse inhibition. The early adolescent stressors used in this study included repeated administration of a bacterial endotoxin, lipopolysaccharide (LPS), or a stressful predator cat odour exposure. In later adolescence and adulthood, rats were administered with a gut microbial by-product, propionic acid (PPA), and subsequently tested on …

Settlement Experiences Of Syrian Refugees, Jennifer Perkins

Electronic Thesis and Dissertation Repository

Statistics Canada (2017) reports that over 40,000 Syrian refugees have arrived in Canada since November of 2015. This large influx of refugees, some with psychological trauma, poses a great responsibility to service providers to ensure services meet the needs of their new clientele. One service provider in Midsized City, Ontario, which will be referred to as The Resource Center, has taken a new and culturally informed approach to providing service. This center has held multiple “Welcome Neighbour” events across the city to invite newcomers to form a closer community and give them the platform to express their needs as refugees. …

Symbolic And Material Justice: The Case Of Displaced Persons In Chocó, Colombia, Allison Cordoba

Electronic Thesis and Dissertation Repository

This research examines the causes and impacts of victimization as experienced by rural populations displaced by conflict living in Quibdó, Colombia. It draws upon Bourdieu’s social theory to understand how the distribution of various forms of capital structure the lives of the displaced. A brief history of the conflict in Colombia is presented, which is broken into five periods, from 1946 to 2014 when the fieldwork was conducted. A description of the context of Quibdó and the department it is in, Chocó, is also provided. Particular attention is paid to the role of symbolic, economic, and cultural capital in the …

Predictors Of Language Outcome For Children In The Ontario Infant Hearing Program, Olivia M. Daub

Electronic Thesis and Dissertation Repository

The Ontario Infant Hearing Program (OIHP) provides early interventions (i.e., hearing aids) to children who are hard of hearing (CHH) because research consistently demonstrates their benefit to language outcomes. The impact of pre-fitting language abilities on these outcomes are not well understood.

This retrospective cohort analysis examined the performance of OIHP children on the Preschool Language Scale-4 at the time of (n=47), and after (n=19), initial hearing aid intervention. Regression analyses revealed that, before amplification, hearing loss severity predicted language abilities. However, after amplification, severity of hearing loss did not uniquely predict language achievement, but rather …

Ethanol Exposure During Synaptogenesis In A Mouse Model Of Fetal Alcohol Spectrum Disorders: Acute And Long-Term Effects On Gene Expression And Behaviour, Morgan L. Kleiber

Electronic Thesis and Dissertation Repository

Alcohol is a neuroactive molecule that is able to exert variable and often detrimental effects on the developing brain, resulting in a broad range of physiological, behavioural, and cognitive phenotypes that characterize ‘fetal alcohol spectrum disorders’ (FASD). Factors affecting the manifestation of these phenotypes include alcohol dosage, timing of exposure, and pattern of maternal alcohol consumption; however, the biological processes that are vulnerable to ethanol at any given neurodevelopmental stage are unclear, as is how their disruption results in the emergence of specific pathological phenotypes later in life.

The research included in this thesis utilizes a C57BL/6J (B6) mouse model …

The Role Of Connexins And Pannexins In Mammary Gland Development And Tumorigenesis, Michael K. G. Stewart

Electronic Thesis and Dissertation Repository

The identification of key regulators of breast cancer onset and progression is critical for the development of targeted therapies. Connexins and pannexins are characterized by their ability to form large-pore channels and are frequently dysregulated in cancer. However, their role in breast cancer progression remains poorly understood due to a lack of in vivo models capable of assessing the proposed and opposing roles of connexins and pannexins as both tumor suppressors and/or facilitators in multiple stages of the disease. Using 2 previously uncharacterized genetically-modified mice, connexin43 (Cx43) and connexin26 (Cx26) were evaluated for their role in normal mammary gland development …

Eyetracking Of Coarticulatory Cue Responses In Children And Adults, Alexandra M. Cross

Electronic Thesis and Dissertation Repository

Studies examining sensitivity to coarticulatory cues during spoken word recognition have typically examined children and adults separately. The present thesis compared sensitivity to coarticulatory cues in school-aged children and adults using eyetracking. Children and adults listened to words containing congruent and incongruent coarticulatory cues while looking at a two-picture display. Contrary to theories positing weakened attention to phonetic detail in children, we observed equal or greater sensitivity to coarticulatory cues in children compared to adults. This effect was related to predictors of reading and language proficiency, and was also modulated by phoneme contrasts such that children were overly sensitive to …

Multi-Method Exploration Of The Economic Sustainability Of Probiotic Yoghurt Kitchens In Mwanza, Tanzania, Emily Eyles

Electronic Thesis and Dissertation Repository

This research aimed to examine the economic and locational aspects of a probiotic yoghurt kitchen development project facilitated by Western Heads East in Mwanza, Tanzania. This study is based upon 41 semi-structured interviews with 57 participants in three groups: kitchen group members, customers, and staff of the African Probiotic Yoghurt Network. This research contributes to the literature on development geography, specifically on the ins and outs of the everyday of the kitchens, as well as proposing a new approach to multicriteria evaluation using qualitative data, and the ‘researcher as instrument’ approach. The results demonstrate that while there are problems in …

Pancreatic Beta Cell Plasticity And Involvement Of Insulin-Expressing Progenitor Cells, Christine A. Beamish

Electronic Thesis and Dissertation Repository

Islet transplants have been successfully used as treatment for diabetes, but are limited by shortages of cadaveric insulin-producing β-cells. An alternate source may be the dedifferentiation, expansion, and subsequent redifferentiation of pancreatic islets or β-cells using in vitro techniques prior to transplant. Based on protocols which described the dedifferentiation of human islets to ductal-like cells, we hypothesized that neonatal mouse islets could be similarly dedifferentiated in vitro. Dedifferentiation techniques produced significant duct-like cells, but redifferentiation to insulin-expressing cells was limited. RIPCre;Z/AP+/+ mice were consequently utilized to lineage trace β-cell fate during culture by a human placental alkaline phosphatase (HPAP) reporter. …

Taking Tone Into Account: Cognitive Neuroscientific Investigations Of Mandarin Chinese Spoken Word Processing, Jeffrey G. Malins

Electronic Thesis and Dissertation Repository

To date, theories of how humans recognize spoken words have yet to account for tonal languages such as Mandarin Chinese. One reason for this is that we know relatively little about how native speakers of tonal languages process spoken words in the brain. This dissertation addresses this problem by examining Mandarin spoken word processing in both adult native speakers and typically developing children. In adults, functional magnetic resonance imaging (fMRI) was used to assess the extent to which the brain regions involved in processing tonal information are distinct from those involved in vowel processing (Chapter 2), while event related potentials …

Developmental Characterization Of Tissue Inhibitor Of Metalloproteinase Domain Functions In Xenopus Laevis, Michelle A. Nieuwesteeg

Electronic Thesis and Dissertation Repository

During development the extracellular matrix is cleaved and remodeled to facilitate the large-scale cell rearrangements that are necessary for processes like gastrulation, neurulation, angiogenesis and organogenesis. ECM remodeling occurs primarily through secreted enzymes called matrix metalloproteinases (MMPs). Regulation of MMP activity is achieved through the tissue inhibitor of metalloproteinases (TIMPs), a small family of secreted proteins that bind MMPs in a 1:1 manner to inhibit their activity. Although TIMPs were originally characterized based on their MMP-inhibitory activities, in vitro studies have revealed that TIMPs are multifunctional proteins, with structurally and functionally distinct N- and C-terminal domains. TIMP N-terminal domains bind …

Tu Envidia Es Mi Progreso: An Ethnographic Account Of The Development Of Squatter Settlements In San Juan De Miraflores, Lima, Peru., Brandon E. Rouleau

Electronic Thesis and Dissertation Repository

The following dissertation explores the past 60 years of self-help housing in Lima. Specifically, it looks at the uneven development that has occurred in parts of a municipality called San Juan de Miraflores. I argue that self-help housing is part of a larger modernization project that aims to encourage the emergence of a self-regulating individual. Pro-development literature creates a selective history of marginal neighbourhoods, effectively silencing the histories of working class Miraflorinos. The aim of this ethnographic study is to destabilize official histories and representations about development in marginal communities. The bulk of the dissertation looks at the history of …

Cloning And Analysis Of Reck During Early Xenopus Laevis Development, Jessica Willson

Electronic Thesis and Dissertation Repository

Extracellular matrix (ECM) remodeling is crucial for the development and maintenance of multicellular organisms. Degradation of ECM components occurs through the activity of matrix metalloproteinases (MMPs) and their inhibitors. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) gene encodes a membrane-anchored protein and plays an important role in mediating ECM remodeling by inhibiting MMPs. To date, few in vivo studies exist examining RECK during development. The present study focuses on cloning and examining the expression of RECK during early Xenopus laevis development. A mature cDNA clone of the RECK gene was generated. RT-PCR, in situ hybridization, and immunohistochemistry were used to …