VictorJuiz/thesis huggingface dataset:
Thermal Stability of Nanocrystalline Copper for Potential Use in Printed Wiring Board Applicatoins
Keywords: thermal stability
nanocrystalline

Copper is a widely used conductor in the manufacture of printed wiring boards (PWB). The trends in miniaturization of electronic devices create increasing challenges to all electronic industries. In particular PWB manufacturers face great challenges because the increasing demands in greater performance and device miniaturization pose enormous difficulties in manufacturing and product reliability. Nanocrystalline and ultrafine grain copper can potentially offer increased reliability and functionality of the PWB due to the increases in strength and achievable wiring density by reduction in grain size. The first part of this thesis is concerned with the synthesis and characterization of nanocrystalline and ultra-fine grain-sized copper for potential applications in the PWB industry. Nanocrystalline copper with different amounts of sulfur impurities (25- 230ppm) and grain sizes (31-49nm) were produced and their hardness, electrical resistivity and etchability were determined. To study the thermal stability of nanocrystalline copper, differential scanning calorimetry and isothermal heat treatments combined with electron microscopy techniques for microstructural analysis were used. Differential scanning calorimetry was chosen to continuously monitor the grain growth process in the temperature range from 40C to 400C. During isothermal annealing experiments samples were annealed at 23C, 100C and 300C to study various potential thermal issues for these materials in PWB applications such as the long-term room temperature thermal stability as well as for temperature excursions above the operation temperature and peak temperature exposure during the PWB manufacturing process. From all annealing experiments the various grain growth events and the overall stability of these materials were analyzed in terms of driving and dragging forces. Experimental evidence is presented which shows that the overall thermal stability, grain boundary character and texture evolution of copper is greatly related to changes in driving and dragging forces, which in turn, are strongly depended on parameters such as annealing temperature and time, total sulfur impurity content and the distribution of the impurities within the material. It was shown that a simple increase in the sulfur impurity level does not necessarily improve the thermal stability of nanocrystalline copper.
The Role of PtdIns(4,5)P2 during Cytokinesis in Drosophila Spermatocytes
Keywords: PIP2
cytokinesis
phospholipid
cleavage

Cytokinesis, the final step of cell division, is characterized by formation of a cleavage furrow that ingresses to separate the cell into two daughter cells. This process requires rearrangement of the cytoskeleton and addition of membrane to the growing furrow. The phospholipid phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] has been implicated in regulating both actin dynamics and membrane trafficking and, thus, is uniquely poised to coordinate these different processes during cytokinesis. In this study, I show that PtdIns(4,5)P2 is involved in another aspect of cytokinesis: regulation of actomyosin contractility. Perturbing PtdIns(4,5)P2 levels in Drosophila spermatocytes caused constriction to fail and cleavage furrows to regress. Moreover, PtdIns(4,5)P2 hydrolysis is implicated in this process: inhibiting PLC or IP3R or chelating Ca2+ also caused defects in furrow ingression. In addition, I show that PLC and MLCK activities are required for myosin light chain phosphorylation and for proper myosin and actin localization to the cleavage furrow. Thus, I propose a model in which PtdIns(4,5)P2 hydrolysis-dependent Ca2+ release activates MLCK via Ca2+/calmodulin to maintain myosin filaments in the contractile ring and regulate cleavage furrow ingression. Furthermore, I show that PtdIns(4,5)P2 has a role in maintaining contractile ring components in the cleavage furrow that does not depend on PtdIns(4,5)P2 hydrolysis. I conclude that PtdIns(4,5)P2 regulates myosin contractility through a PLC-dependent pathway leading to myosin phosphorylation and is also involved in localizing contractile ring components to the furrow. Thus, PtdIns(4,5)P2 may coordinate signals leading to cytoskeleton rearrangement and actomyosin contractility during cytokinesis.
Effects of Early Thyroid Hormone Deficiency on Autobiographical Memory and Hippocampal Structure and Function during Late Childhood and Early Adolescence
Keywords: Memory
Hippocampus
Thyroid
Childhood

The hippocampus, which is a critical brain region for episodic autobiographical memory (AM), is particularly vulnerable to damage following periods of early thyroid hormone (TH) deficiency. Although numerous studies have examined AM performance in adult patients with hippocampal damage, no study has yet examined AM in children exposed to early TH deficiency, such as children with congenital hypothyroidism (CH) and offspring of women who were hypothyroid during pregnancy (HYPO). Given that both animal and human studies have shown that early TH deficiency results in significant hippocampal abnormalities and memory impairments, the purpose of this dissertation was to investigate the effects of early TH deficiency on AM and hippocampal structure and function during childhood. Study I examined AM performance in a large sample of typically developing children and adolescents in order to validate the use of the newly-developed Children’s Autobiographical Interview (CAI). In Study II, the CAI was used to investigate AM performance in children with early TH deficiency (i.e., CH and HYPO groups). Similar to the findings observed in adults with hippocampal damage, CH and HYPO groups both exhibited weaknesses in episodic AM, but not semantic AM, relative to controls. In addition, structural MRI revealed mild bilateral hippocampal volume reductions in HYPO, but not CH, which is consistent with animal models suggesting that early prenatal TH deficiency (i.e., HYPO) may be associated with greater abnormalities in hippocampal structure than postnatal TH deficiency (i.e., CH). Study III investigated children’s AM accuracy performance using a staged event and indicated that children with early TH deficiency had proportionally less accurate recollections of the staged event than controls. Importantly, smaller hippocampal volumes in both CH and HYPO groups predicted lower AM accuracy scores. Finally, in Study IV, functional MRI revealed that children with early TH deficiency exhibited abnormal (i.e., greater bilateral) hippocampal activation during episodic AM retrieval, but not during semantic AM retrieval, relative to controls, which may reflect neural compensation or may be a by-product of the degree of hippocampal damage. Overall, this dissertation provides critical new insight into the long-term effects of early TH deficiency on children’s AM performance and the hippocampus.
Leadership Supports for First-time Vice-principals: Coaching as a Form of Professional Learning
Keywords: leadership
vice-principal
coaching
professional learning
elementary

The purpose of this research was to learn about how coaching serves as a form of professional learning for newly-appointed vice-principals. This study is intended to add to our understanding of the ways in which coaching supports the professional learning of vice-principals in a context where their role is ill-defined and determined by their principal. A qualitative research approach was used which included personal interviews with fourteen first-time elementary vice-principals in five Ontario school districts. The study was based on the following research question: How does the coaching experience support the professional learning of first-time school administrators? The participants reported positive feelings about their coaching experiences. Specifically, they described that they appreciated the confidential and non-evaluative nature of the coaching relationship, that the focus was on their individual learning needs, and that the coaching provided opportunities to engage in reflective thinking. In terms of their learning, the participants reported that through coaching they built confidence, gained knowledge about both the managerial and leadership aspects of school leader roles, and that they learned about themselves and their own well-being in the process. Several challenges were reported. These included a desire for increased frequency of scheduled coaching sessions while maintaining a focus on learning during the sessions, and financial constraints for those who needed to be released from teaching responsibilities in order to participate in coaching. Based on their experiences, the participants described the vice-principal role as being determined by the principal, offering limited opportunity to exercise their own leadership, expecting them to follow decisions made by the principal, and serving to prepare them for the principalship. The thesis concludes that coaching for newly-appointed elementary vice-principals is a valuable experience because it serves as personalized professional learning that engages participants in reflective thought. The lack of clarity about the vice-principal role creates a situation where vice-principals understand their role principally through their experiences of it, not through research, policy, or training. As a result, each vice-principal has unique learning needs based on their experience of the role thus they benefit when their learning is personalized.
Hippocampal Functioning in Adolescents with Congenital Hypothyroidism
Keywords: memory
congenital hypothyroidism
functional imaging
hippocampus

Congenital hypothyroidism (CH) is a pediatric endocrine disorder caused by an insufficiency of thyroid hormone. Despite treatment following newborn screening, CH is associated with persisting memory weaknesses. Given animal research has shown thyroid hormone plays a crucial role in the development of the hippocampus, a brain structure required for normal declarative memory, it is possible that altered hippocampally-dependent processes underlie the memory weakness associated with CH. Previous studies of individuals with CH have found reduced memory abilities and left hippocampal volumes but no study has thoroughly assessed memory abilities or how the hippocampus functions to support memory. Thus, the present study compared individuals with CH and typically developing adolescents using clinical memory tests and two associative memory tasks shown in adults to activate the hippocampus during functional magnetic resonance imaging (fMRI). Results indicated groups did not differ in memory accuracy on clinical measures or either fMRI task. However, fMRI revealed hippocampal activation differed between the groups when performing the associative memory tasks. The first task utilized a visuospatial paired associates novelty detection paradigm to show the CH group increased activation relative to controls in left hippocampus and recruited right hippocampus when controls did not. Since previous research suggested the left hippocampus and verbal memory were more vulnerable to the effects of CH, the second task utilized a verbal paired associates paradigm to demonstrate that when making old and new judgments about associations versus items, the CH group increased activation relative to controls in left hippocampus. Further investigation revealed that when recognizing old associations versus items, the CH group had increased bilateral posterior hippocampal activation whereas controls showed increased activation in right anterior hippocampus, a distinction noted in previous research with this paradigm which suggests individuals with CH may retrieve associations in a less flexible manner than controls. In addition, worse memory performance and increased hippocampal activation, particularly on the left, was predicted by severity of hypothyroidism experienced early in life. In conclusion, these studies demonstrate that early thyroid hormone insufficiency associated with CH alters the functioning of the hippocampus and engenders use of compensatory mechanisms to support associative memory functions.
Tragic Desire: Phaedra and her Heirs in Ovid
Keywords: Ovid
Phaedra
Hippolytus
abject
Augustan poetry
Metamorphoses
Heroides
Ars Amatoria

In this thesis, I explore the construction of female erotic desire in Ovid’s work as it is represented in the form of mythical heroines. Phaedra-like figures appear in Ovid’s poetry as dangerous spectres of wildly inappropriate and therefore destructive, bestial, or incestuous sexuality. I consider in particular the catalogue of Phaedra-like figures in Ars Amatoria 1.283-340, Phaedra in Heroides 4, Byblis in Metamorphoses 9.439-665, and Iphis in Metamorphoses 9.666-797. Their tales act as a threat of punishment for any inappropriate desire. They represent for the normative sexual subject a sexual desire which has been excluded, and what could happen, what the normative subject could become, were he or she to transgress taboos and laws governing sexual relations. I apply the idea of the abject, as it has been formulated by Julia Kristeva and Judith Butler, in order to elucidate Ovid’s process of constructing such a subject in his poetry. I also consider Butler’s theories of the performativity of sex, gender, and kinship roles in relation to the continued maintenance of the normative and abject subject positions his poetry creates. The intersection of “performance” and performativity is crucial to the representation of the heroines as paradigms of female desire. Ovid’s engagement with his literary predecessors in the genre of tragedy, in particular Euripides’ and Sophocles’ tragedies featuring Phaedra, highlights the idea of dramatically “performing” a role, e.g., the role of incestuous step-mother. Such a spotlight on “performance” in all of these literary representations reveals the performativity of culturally defined gender and kinship roles. Ovid’s ludic representations, or “citations,” of Phaedra, I argue, both reinvest cultural stereotypes of women’s sexuality with authority through their repetition and introduce new possibilities of feminine subjectivity and sexuality through the variations in each iteration.
The Development of Novel Protein Topology Mapping Strategies using Crosslinking, Cyanogen Bromide Cleavage, and Mass Spectrometry
Keywords: protein structure
mass spectrometry
chemical crosslinking
interface mapping
proteomics
protein topology mapping
cyanogen bromide
interactome
method development
HPLC

Advances in protein topology mapping methods are urgently needed to complement the wealth of interactome data that is presently being generated at a rapid pace. Chemical crosslinking followed by mass spectrometry (MS) has evolved over the last decade as an attractive method for protein topology and interface mapping, and holds great promise as a counterpart to modern interactome studies in the field of proteomics. Furthermore, stabilization of proteins and protein complexes with crosslinking offers many advantages over high-resolution structural mapping methods, including the ability to study protein topologies in vivo. The reliance on direct detection of crosslinked peptides, however, continues to pose challenges to protein topology and interface mapping with chemical crosslinking plus MS. The present body of work aimed to develop a novel generic methodology that utilizes chemical crosslinking, cyanogen bromide (CNBr) cleavage and MS for the low-resolution mapping of protein topologies and interfaces. Through such low-resolution mapping of crosslinked regions, this novel strategy overcomes limitations associated with the direct detection of crosslinked peptides. Following optimization of various steps, the present method was validated with the bacterial DNA-directed RNA polymerase core complex and was subsequently applied to probe the tetrameric assembly of yeast Skp1p-Cdc4p heterodimers. Further improvements were made through the enrichment of crosslinked CNBr-cleaved protein fragments prior to their identification via MS. Two enrichment strategies were developed which depended upon the conjugation of tags to CNBr-cleaved peptide C-termini followed by either tandem affinity purification or tandem reversed-phase HPLC purification. These strategies were successfully applied for the efficient purification of disulfide-linked peptides from peptide mixtures. It is expected that the potential to achieve sensitive mapping of topologies and interfaces of multi-subunit protein complexes in vivo, in combination with further enhancements to permit studies on complex protein samples, will extend the utility of this method to complement large-scale interactome studies.
Social and Linguistic Correlates of Adverb Variability in English: A Cross-varietal Perspective
Keywords: Language variation and change
Adverbs

Linguistic research on adverbs has taken many forms: typological, morphological, syntactic, semantic and pragmatic. However, little work has been conducted on adverbs using the tools of quantitative sociolinguistics, and most of that work has focused solely on morphological variation of the -ly suffix. This work addresses the lacuna by examining two adverb phenomena using quantitative variationist methodology. Data come from two large, socially stratified, sociolinguistic corpora of vernacular English. The two corpora contain data collected in Ontario, Canada and in Northern England, and are comprised of the speech of over 150 speakers across all age groups. In the first case study, I examine a claim in usage guides (e.g., Swan 2001) that North American English widely permits pre-auxiliary adverbs in canonical, declarative sentences, while British English prohibits them unless accompanied by contrastive stress. As I show, the varietal differences in speech are not only minimal and unrelated to stress, but instead are highly circumscribed. In addition, I demonstrate that the positioning of adverbs observed here must involve post-syntactic processes. The second case study examines variability in the discourse adverb "actually" and several related adverbials (e.g., "really" and "in fact") and examines the path of grammaticalization (Traugott & Dasher 2002) in the two communities. I demonstrate that Canadians, regardless of sex or education level, prefer the more grammaticalized forms of "actually"; in the UK, the more grammaticalized use is less common, though some young men are leading a shift to the more grammaticalized pattern.
Le Réalisme magique dans la littérature contemporaine québécoise
Keywords: réalisme magique
québécois

La présente thèse est une exploration du genre réaliste magique de la littérature contemporaine québécoise. Fondée sur quatre romans exhibant de manière saisissante des aspects du réalisme magique, informée par des ouvrages théoriques ainsi que des analyses de textes réalistes magiques séminaux, et éclairée par la sociocritique québécoise, cette étude vise à élucider le fonctionnement du genre et ses particularités dans la littérature québécoise de 1975 à l’époque actuelle. Pour mener ce travail, nous analysons: Les Enfants du sabbat d’Anne Hébert, Le Trou dans le mur de Michel Tremblay, L’Ombre de l’épervier de Noël Audet et La Tribu de François Barcelo. Chaque roman a été choisi afin de démontrer les modalités et les spécificités québécoises du genre. Le réalisme magique étant un terme dont les origines sont problématiques et variées, nous présentons d’abord un historique du genre. À la suite d’une présentation des concepts théoriques, nous identifions les caractéristiques principales du réalisme magique. Notre analyse des Enfants du sabbat met en lumière le rôle des codes antinomiques (le réel et le surnaturel) et quelques thèmes fondamentaux du réalisme magique propre au contexte de production. Nous nous penchons ensuite sur le personnage fantôme, un dispositif réaliste magique qui déclenche un commentaire sur le contexte social dans Le Trou dans le mur. Dans L’Ombre de l’épervier, en plus du personnage-écrivain qui s’impose dans la diégèse, tout un réseau de personnages est marqué par l’altérité notamment la figure de la femme et de la sorcière. La Tribu, dont les caractéristiques réalistes magiques sont incontestables, s’avère un roman ludique. Après une analyse du jeu onomastique, nous comparons La Tribu au roman de Gabriel García Márquez, Cien años de soledad. Dans un dernier temps, nous démontrons comment les multiples représentations de la femme et de l’oralité traversent l’ensemble du corpus tout en indexant des particularités du réalisme magique dans la littérature contemporaine québécoise.
Gratitude as a Mechanism by which Agreeable Individuals Maintain Good Quality Interpersonal Relationships
Keywords: gratitude
relationships
agreeableness
psychology
multi-method
personality

The current dissertation employed a multi-method approach to examine gratitude as a mediator of the well-established relation between agreeableness and relationship quality. Study 1 examined this hypothesis in a sample of 158 same-sex best friend pair recruited from the Introductory Psychology subject pool at the University of Toronto, Mississauga. Each friend made self- and informant ratings of agreeableness and dispositional gratitude. Friends also made self-ratings of friendship quality. Structural equation model analyses with latent factors revealed that dispositional gratitude fully mediated the effects of agreeableness on friendship support, intimacy, and affection. Study 2 extended the findings of Study 1 by examining whether frequency of grateful affect was a more proximal mediator of the relation between agreeableness and marital quality. One hundred and ninety-seven family triads (student, mother and father) were recruited from the Introductory Psychology subject pools at the University of Toronto, St. George and Mississauga. Each member of the triad made self- and informant ratings of agreeableness, dispositional gratitude, frequency of grateful affect, and relationship quality. Structural equation model analyses with latent factors showed that frequency of spouses’ grateful affect fully mediated the effects of spouses’ agreeableness on marital support and intimacy and partially mediated the effect of agreeableness on marital companionship and affection. In sum, the findings of the current dissertation suggest that gratitude is one way in which agreeable individuals maintain good quality friendships and marital relationships. The implications of these results for current theories of gratitude as well as relationship research are discussed.