VictorJuiz/thesis huggingface dataset:
X-ray Spectroscopy Studies of Iridates and Iron Based Superconductors
Keywords: Iridates
Superconductors

Ir L3 edge Resonant Inelastic X-ray Scattering (RIXS) and La2 Resonant X-ray Emission Spectroscopy (RXES) have been used to investigate A2IrO3 (A= Na or Li) and CuIr2S4. First principle calculations show that the low-energy dd-excitations in the RIXS spectra of A2IrO3 originate from a split jeff=3/2 to jeff=1/2 excitation. A magnetic excitation is observed in Na2IrO3, whose dispersion is consistent with the theoretical prediction including a bond-dependent Kitaev interaction between jeff=1/2 magnetic moments. In CuIr2S4, RXES measurements reveal that the unoccupied Ir t2g level shift upward in energy as a result of the metal-insulator transition, confirming density functional theory calculations. In the x-ray irradiation induced phase of CuIr2S4, a mid-infrared peak emerges in the RIXS spectrum around 0.4 eV, suggesting that both the crystal structure and the electronic structure are modified due to x-ray irradiation. The size of the magnetic moments in Fe based superconductors has been investigated using Fe Kb X-ray Emission Spectroscopy (XES). Local magnetic moments are found in Fe pnictides and chalcogenides, independent of temperature or carrier concentration. This result supports the notion of local moments coexisting with metallic bands. Our investigation of Ca{1-x}RExFe2As2 (RE=La, Pr, and Nd) shows results consistent with a spin-state transition. We argue that the gradual change of the spin-state over a wide temperature range reveals the importance of multiorbital physics, and in particular the competition between the crystal field split Fe 3d orbitals and the Hund's rule coupling.
Human Resources Programming and its Impact on Leadership within Governing Boards of Ontario Community Colleges
Keywords: Governance
College boards

This study investigated the direct experiences and preferences of Ontario community college board members and board secretaries to determine how specific programming related to governor recruitment, selection, training and performance evaluation assisted, or may contribute to, governance and leadership experiences during their term in office. These experiences and viewpoints were referenced against the scholarly literature in the domains of contemporary human resources management as well as board governance and leadership. Particular attention was paid to two recent models developed by Leblanc and Gillies (2005) and Chait, Ryan and Taylor (2005) which focus attention on desired leadership and governance practices in not-for-profit institutional settings. Two principal research groups, including college governors and board secretaries, at twenty-two provincial community colleges were invited to complete separate on-line questionnaires which addressed their experiences in four specific human resources management program areas as well as their preferences for how such activities should be carried out. Trends in survey results for both groups were then explored via telephone interviews with five board leaders at community colleges that had participated in the on-line surveys. The results of the study identified several areas where Ontario community colleges utilized contemporary human resources management processes in dealing with members of their boards of governors. The research results also confirmed opportunities for strengthening certain board management practices, through the sharing of expertise with the college’s human resources staff or with the assistance of third party expertise, to strengthen the individual and collective leadership of those serving in governing roles at these higher education institutions.
Biophysical and Structural Studies of Lipopeptide Detergents
Keywords: Membrane proteins
Structure Crystallization

Biochemical and structural studies of membrane protein usually require their stabilization in solution with detergents. However, purified membrane proteins often show reduced activity and stability in traditional detergents. Lipopeptide detergents (LPDs) are a new class of engineered amphiphiles that from small micelles and mimic the lipid bilayer more closely than traditional detergents. An LPD molecule consists of an &alpha;-helical peptide with fatty acyl chains covalently attached to both ends. These molecules self-assemble into cylindrical micelles with a hydrophilic exterior and a hydrophobic interior made up of the fatty acyl chains. Here we present the biophysical and biochemical properties of a model bacterial ABC transporter, MsbA, in different LPD variations. Four types of LPD molecules have been synthesized and have been categorized as original LPD, LPD5Q, LPD2, and LPD4 based on the peptide sequence. Dynamic light scattering, thermal aggregation, and ATPase activity were used to measure the biophysical properties of MsbA in LPDs and in a traditional detergent, n-decyl-&beta;-D-maltoside (DM). The results show that MsbA-LPD particles are monodisperse with small hydrodynamic radii. When compared to DM, MsbA is thermodynamically more stable and has higher catalytic activity in LPDs. Membrane proteins have favorable biophysical properties in LPDs, suggesting that these detergents resemble the native lipid bilayer environment more closely. We also present crystal structures of three LPDs: LPD-12, LPD5Q-14 and LPD- 14. These structures reveal that LPD micelles are highly ordered with varying oligomeric states. The octomeric structure of the LPD-12 micelle is composed of four sets of antiparallel coiled-coil dimers, while the LPD5Q-14 micelle assembles as a nonamer of three trimers each with an &ldquo;up-up-down&rdquo; topology. The LPD-14 micelle, on the other hand, is a dodecamer of three tetramers with all helices assuming an antiparallel orientation. Overall, the structures of LPDs show highly ordered detergent micelles that are made up of repeated building blocks. Based on these results, we propose that LPDs can sample multiple conformational states, but the number of accessible conformations is significantly reduced relative to traditional detergents. Our results show that LPDs are an alternative platform for in vitro studies of membrane proteins. Future studies will focus on the crystallization of membrane proteins in LPDs and the further characterization of these complexes.
25-hydroxyvitamin D and Biomarkers of Cardiometabolic Disease
Keywords: 25-hydroxyvitamin D
Cardiometabolic disease
Biomarkers
Young adults

Background: Vitamin D may have beneficial effects on cardiometabolic disease, but the evidence is equivocal. This may be due to unaccounted confounders, such as lifestyle factors and genetic variation. We examined the association between circulating 25-hydroxyvitamin D [25(OH)D] and biomarkers of cardiometabolic disease risk, including biomarkers of inflammation, glycemic dysregulation and lipid metabolism, and a panel of 54 plasma proteomic biomarkers, and determined whether lifestyle variables and genetic variation modified these associations. Methods: Participants were from the Toronto Nutrigenomics and Health Study, an ethnically diverse population of individuals aged 20-29 years. Anthropometric measurements were obtained. Participants answered general health and lifestyle and food frequency questionnaires and provided a fasting blood sample for biochemical measurements and genotyping. Results: Across ethnic groups, women who used hormonal contraceptives (HC) had higher 25(OH)D and C-reactive protein (CRP) than women HC non-users and men. Circulating 25(OH)D was positively associated with CRP in the entire population in models not accounting for HC use. However, there was no association after accounting for HC use. 25(OH)D was also not associated with inflammatory cytokines after adjusting for HC use. 25(OH)D was inversely associated with insulin, HOMA-IR, and HOMA-Beta among Caucasians and East Asians and among men and women HC non-users. No biomarkers were associated with 25(OH)D among South Asians and women HC users, although non-significant inverse trends were observed for markers of glycemic dysregulation. Only two of the 54 plasma proteomic biomarkers were associated with 25(OH)D in women HC non-users, and none were associated in men. Among women HC users, after accounting for hormone dose, only three proteins were associated with 25(OH)D. Finally, 25(OH)D affected the association between rs2239182, a variant in the vitamin D receptor (VDR) and the pro-inflammatory cytokine interferon gamma-induced protein 10 (IP-10). However, the association was suggestive of heterosis and may have been due to chance. Conclusions: We identified a confounding effect of HC use on the association between 25(OH)D, biomarkers of inflammation and plasma proteomic biomarkers. In addition, HC use might also affect the association between 25(OH)D and biomarkers of glycemic dysregulation. Genetic variation in VDR did not modify any associations.
Interpreting Brazilianness: Reception and Representation in the Brazilian Music Scenes of Toronto and Montreal
Keywords: Music and migration
Intercultural dynamics
Cultural representation
Audiences and reception
Exoticist ideologies

In Toronto and Montreal, Brazilian popular music performances constitute a context for intercultural encounter. Performances offer Brazilians the opportunity to present their culture of origin while emphasising their identification with it. The issue of representation is quite complex, however, due to the involvement of a majority of non-Brazilian musicians, audience members, artistic directors, producers, promoters, and journalists. This dissertation focuses on music reception and cultural representation and how these may influence each other after music has been decontextualised and recontextualised. I look closely at local non-Brazilian audiences possessing different degrees of familiarity with Brazilian music, and I demonstrate how cultural stereotypes influence their conceptions and expectations of Brazilian music, culture, and people. I argue that a desire for cultural difference and the exotic, encouraged by discourses of cultural diversity, influences the reception of performances. I suggest that, through the privileged gaze of non-Brazilian attendees, performances may be adjusted to correspond to audience fantasies of Brazil. Some non-Brazilians would like to become knowledgeable of, and even intimate with Brazilian culture, which would satisfy their desire to be cosmopolitan. However, pleasure frequently matters more to them than a nuanced understanding of Brazilian culture; this explains, I contend, why some Torontonians and Montrealers have become comfortable with essentialist and stereotypical representations. I examine how some non-Brazilian musicians, promoters, and band agents reinforce mythologies of Brazil to meet audience demands and sometimes to satisfy their own fantasies. I analyse the reproduction of similarly problematic discourses on Brazil in the presentations of Brazilian artists as both a form of autoexoticism and a particular type of tactical or strategic essentialism. Rather than to represent and understand Brazilian culture, I argue that, through local music performances, Brazilians and non-Brazilians in Toronto and Montreal interpret Brazilianness.
Part-time Nurse Faculty Intent to Remain Employed in the Academic Organization
Keywords: retention
intent to remain
intent to stay
nurse faculty
nursing faculty
theoretical model
theory testing

Part-time nurse faculty play an important role in the production and quality of the nursing workforce. However, the shortage of nurse faculty exacerbates current shortages of nurses. In Canada, the shortage is predicted to reach 60,000 full-time equivalent RNs by 2022. Therefore, retaining qualified part-time nurse faculty in academia is a key component in managing the shortage problem. The purpose of this study was to test and refine a model of part-time nurse faculty intent to remain employed in the academic organization. Cross-sectional survey methods were employed. A total of 282 part-time nurse faculty employed within Ontario, Canada colleges or universities were invited to participate. Survey instruments and items measured demographic, workplace, nurse responses to the workplace, and external variables. Correlation and multiple regression analyses were conducted using data from 119 participants (47.6% true response rate). Of the 19 variables hypothesized to affect intent to remain employed in the academic organization, seven influenced intent to remain. The resulting model indicated that the older the part-time nurse faculty member, the lower the level of intent to remain and the more years worked in the organization, the higher the level of intent to remain. The more opportunities perceived to exist outside of the employing organization, the higher the level of intent to remain. Additionally, the more satisfied part-time nurse faculty were with their job overall, the higher their level of intent to remain. In the workplace, the more support from the leader, the more formal or informal recognition received, and the more fair work procedures were perceived to be, the higher levels of part-time nurse faculty intent to remain employed in the academic organization, mediated by job satisfaction. Although age, organizational tenure, and external career opportunities are non-modifiable variables, deans and directors can encourage part-time nurse faculty to remain employed in their academic job by focusing on enhancing overall job satisfaction. Effective strategies may include formal or informal acknowledgement of good performance, consistent verbal and behavioural support, and implementation of procedural practices, such as performance evaluations and pay raises in a fair manner.
Exploring School Principal Preparation and Development in Northern Canada: The Case of Nunavut's Educational Leadership Program (ELP)
Keywords: principal preparation
Aboriginal education
educational leadership
Inuit educational aspirations
transfer of learning
leadership training/leadership orientation

The purpose of this research was to explore how Nunavut Educational Leadership (ELP), a school principal preparation program in Nunavut Territory, Canada, fulfills Inuit (the indigenous people of the territory) educational aspirations. In accordance with this purpose, the study focuses on answering four specific questions: (1) what are Inuit educational aspirations? (2) What is the context for Inuit education? (3) How is the Nunavut Educational Leadership Program organized to meet its objectives? (4) How do the activities of the Nunavut Educational Leadership Program (ELP) fulfill Inuit educational aspirations? Adopting an exploratory case study design grounded in qualitative approaches and undergirded by critical interpretative perspective, the research triangulates both primary and secondary sources of data. The primary data sources come from individual semi-structured interviews of 35 respondents (18 community members, 3 program development members, 3 presenters/facilitators, 7 program participants, and 4 educational officials) selected across Nunavut Territory. These sources are complemented with relevant secondary documents from 1987 to 2010. Using constant comparative and word-in-context as the main data analysis methods, concepts and themes were delineated from the data sources to form categories, with the research questions and conceptual framework guiding the process. The research results revealed, among many other things, that the Nunavut ELP partially fulfills Inuit educational aspirations as defined in the research. Issues arising from the data analysis and interpretation are also discussed under (1) Inuit culturally appropriate education/ self-determination in education, (2) Issues associated with Inuit and mainstream relationship, (3) The relationship between context and principal preparation and development programs, (4) Preparation programs for fulfilling local educational aspirations, (5) Framework for principal leadership practice, (6) Educational Governance Related-Issues, (7) University contribution to principal leadership preparation and development programs, (8) Nunavut ELP goals, and (9) Leadership Conceptualizations. Along with these are recommendations, theoretical implications and directions for future or further research. Though the research does not purport to design an educational leadership program for Nunavut school leaders, its evidence-based analysis and results may assist in any conversations toward the restructuring, improvement or enhancement of the Nunavut ELP as well as any educational leadership development programs in post-colonial societies.
Noradrenergic Deficits Contribute to Impairment in the TgCRND8 Mouse Model of Alzheimer's Disease
Keywords: Alzheimer's Disease
Memory
Neurotransmission
Transgenic Mice

Autosomal-dominant mutations in the amyloid precursor protein (APP) gene increase the production and aggregation of toxic amyloid-β (Aβ) peptides and cause early-onset Alzheimer’s disease (AD). Noradrenergic cell loss is well documented in AD and has been posited to play a role in cognitive symptoms as well as disease progression. We investigated memory and affect, tissue levels of catecholamines, brain-derived neurotrophic factor (BDNF) mRNA and bioenergetic homeostasis in TgCRND8 mice that express a double mutant (K670N/M671L + V717F) human APP695 transgene. We found that TgCRND8 mice develop object memory impairment and behavioural despair, as well as reductions in noradrenaline and BDNF expression in the hippocampus and cortex, before the appearance of Aβ plaques. Animals with more advanced Aβ pathology exhibit disruptions in energetic status, along with diminished complex I+III activity in the electron transport chain. To test whether the AD-like phenotypes of TgCRND8 mice might be due to altered noradrenergic tone, pre-plaque mice were treated with dexefaroxan, an antagonist of presynaptic inhibitory α2-adrenoceptors that are highly expressed on both noradrenergic and cholinergic terminals. Effects of dexefaroxan were compared to those of rivastigmine, a cholinesterase inhibitor. Both dexefaroxan and rivastigmine improved behavioural phenotypes and BDNF expression without affecting tissue Aβ load. Drug treatments also restored complex I+III mitochondrial activity and increased ATP levels. Reductions in noradrenergic tone appear to underlie Aβ-induced functional impairment in TgCRND8 mice, in addition to BDNF deficits and bioenergetic stress. These studies suggest that α2-adrenoceptor targeting may warrant consideration as a therapeutic strategy in AD.
Delineation of Vascular Disruption and Investigation of a Bioengineered ZFP-VEGF Gene Therapy Following Traumatic Spinal Cord Injury
Keywords: neuroscience
gene therapy
spinal cord injury
vascular endothelial growth factor

Background: Traumatic spinal cord injury (SCI) results in vascular disruption which appears to contribute to the pathobiology of SCI. Vascular endothelial growth factor (VEGF) is known for vascular development and repair, and more recently for its neuroprotective properties. Given this, I investigated the temporal-spatial changes to the spinal vasculature, as well as examined the role of VEGF as a therapeutic approach for SCI. Hypothesis: It is hypothesized that clip-compression injury will result in significant vascular changes, and that ZFP-VEGF gene therapy will enhance molecular and functional recovery following spinal cord injury. Methods: Briefly, female Wistar rats received a two-level laminectomy and a 35g clip-compression injury at T6-T7 for 1 minute. Control animals received a laminectomy only. AdV-ZFP-VEGF or AdV-eGFP was administered 24 hour post-injury by intraspinal injection. For molecular and vascular analysis, tissues were extracted at various time points between 1 hour and 14 days post-SCI. For behavioural experiments animals were studied for 8 consecutive weeks. Results: I have shown that vasculature undergoes structural and functional changes, which occur as early as 1 hour following SCI. Although endogenous improvement is observed, SCI results in permanent vascular damage. Animals receiving AdV-ZFP-VEGF treatment had increased levels of VEGF mRNA and protein. AdV-ZFP-VEGF resulted in neuroprotection, as observed by increased NF200 protein and NeuN counts, and decreased TUNEL staining. Animals treated with AdV-ZFP-VEGF also showed an increased number of newly formed vessels (angiogenesis), as well as an increase in total number of vessels. Moreover, animals treated with AdV-ZFP-VEGF showed significant increases in hindlimb weight support and reduction neuropathic pain. Conclusions: I have characterized the dramatic temporal-spatial changes which occur in the spinal vasculature following SCI. Additionally, I have demonstrated that AdV-ZFP-VEGF administration results in beneficial molecular and functional outcomes. Overall, the results of this study indicate that AdV-ZFP-VEGF administration can be delivered in a clinically relevant time-window following SCI (24 hours) and provide significant molecular and neurobehavioural benefits, by acting through angiogenic and neuroprotective mechanisms.
Representing and Reasoning about Skills and Competencies over Time
Keywords: expert profiling
skills and competency management
human resource management
skills ontology

To stay competitive within the market, organizations need to accurately understand the skills and competencies of their human resources to better utilize them and more effectively respond to internal and external demands for expertise. This is particularly important for most services organizations which provide a variety of products and services to multiple and changing clients. The ability to accurately locate experts is also important to knowledge workers. From this perspective, finding individuals with appropriate knowledge and skills is important for accomplishing knowledge intensive tasks and solving complex problems. This thesis focuses on the problem of representing and reasoning about skills and competencies over time for more effective human resources management and expert finding. Proper modeling of skills and competencies provides, among other things, a common language for assessments, a foundation for consistent interviewing, a linkage between performance management and learning, and a means for aligning business strategy and skills for driving organizational performance. It also improves knowledge management by making explicit what the organization knows and can perform. In this thesis, we present a framework for profiling human resources over time. In particular, we use first-order logic to represent and reason about expertise, skills and competencies and capture information about sources of skill and competency information. The framework provides: - a formal ontology for skill and competency management which specifies how individuals should be represented and evaluated against a skill, - a technique for inferring and validating skills and competencies over time using different sources of information, - a systematic way of evaluating human resources in order to provide a more efficient, structured, and consistent assessment process, and - techniques for identifying unreliable sources of information and revising trust in these sources. This work enhances the ability of organizations to better utilize their human assets and improves the task of expert finding required for accomplishing knowledge intensive tasks and solving complex problems.