VictorJuiz/thesis huggingface dataset:
Virtual air gap analysis

This thesis presents two approaches to the analysis of a single-phase transformer with a virtual air gap. The transformer has embedded four small auxiliary windings that locally saturate the core. These windings change the magnetic characteristics of the core and create a virtual air gap. The methods focus on the computation of the change in the reluctance of the transformer core with local saturation and on obtaining the equivalent length of the virtual air gap. The first approach is based on the finite element method (FEM) and uses a commercially available FEM computer program to simulate and solve the magnetic circuit with and without local saturation. The second one is an analytical method that calculates the equivalent length of the virtual air gap by finding the distribution of the magnetic field in the core produced by the auxiliary windings. The magnetic field calculation is used to obtain the operating point of the core and the change in the reluctance of the core. The results obtained from the FEM and the proposed analytical method are compared with experimental results available in the literature.
The aryl hydrocarbon receptor: Impact of structural variation of the transactivation domain and interaction with a transcriptional repressor

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor whose activation results in both beneficial and harmful responses. AHR signalling is regulated by numerous factors that act at various points within its pathway. The majority of these factors are proteins that associate with AHR via specific domains within each partner. Thus, variation in the abundance or structure of AHR and/or its interacting factors could modify these associations and subsequently affect AHR signalling. I assessed the impact of AHR expression on AHR signalling in vitro. I observed changes in gene expression resulting from ectopic expression of AHR in AHR-null cell lines in the absence of exogenous ligand treatment. I also observed an inhibition of this induction by inhibition of the ligand-activation step. AHR is a modular protein containing regions attributed with specific functions. The multi-region transactivation domain (TAD) is critical to AHR-mediated gene transcription. The TAD is structurally divergent among various species and is polymorphic in humans and animals. Previous studies assessing the relationship between structure and function of the TAD are inconsistent and hint that cell-context might modify TAD function. I showed that variation in both TAD structure and the cell line in which the study was performed interacted to modify the role of the transactivation domain. These results suggest that multiple dependent and independent variables interact to modify transactivation domain function. It is possible that these variables represent modified domains within the TAD and/or its interacting partners resulting in perturbed TAD:protein interactions. The locus that encodes the protein hairless (HR), a nuclear receptor co-repressor, is a negative modulator of the Ahr locus in mice. I found that HR suppressed the ability of activated AHR to induce gene expression and that HR and AHR physically associate via specific domains. This work identifies AHR-mediated gene transcription as a target of HR co-repressor activity and provides mechanistic insight into the interaction between Hr and Ahr loci. These studies highlight novel factors that regulate AHR and contribute to mounting evidence that mechanistically, AHR signalling may not proceed according to a universal paradigm.
Making sense of international mindedness in the international baccalaureate diploma program

This study investigates the processes that International Baccalaureate Diploma Program educators use to make sense of international mindedness, a key component of the program's educational philosophy. Its theoretical framework is informed by the work of educational researchers, such as James Spillane and Cynthia Coburn, who use a cognitive approach to studying policy implementation in schools. Using data collected through questionnaires, semi-structured interviews and document analysis, this study considers how practitioners' personal histories, professional experiences and local contexts affect their understandings of the philosophical underpinnings of the IB Diploma Program. The findings conclude that because international mindedness represents an attitude or personal disposition rather than a specific process or procedure, philosophical concepts appear to be outliers in terms of the typical sensemaking activities that surround program implementation.
Mitochondrial alternative oxidase, reactive oxygen species and programmed cell death in Nicotiana tabacum

Programmed cell death (PCD) is an integral component of many plant biological processes including senescence, xylem differentiation and as a response to both biotic and abiotic stresses. Understanding how PCD functions in plants will lead to better understanding of these important biological processes. Unlike animal PCD, plant PCD has not been well studied and as such, the mechanisms of plant PCD pathways and their regulation remain unclear. The mitochondrion is known to play an important role in the activation and regulation of many animal PCD pathways; however, the role of the mitochondrion in plant PCD is poorly understood. It could differ from that in animals, for example, due to the existence of additional electron transport chain components. One such component is the alternative oxidase (AOX), which represents a branch of the mitochondrial electron transport chain that accepts electrons from ubiquinol and catalyzes the reduction of oxygen to water. Interestingly, we found that AOX influenced the level of cellular reactive oxygen species (ROS), which strongly correlated with susceptibility to cell death induced by well-known hypersensitive response (HR)-associated signaling molecules including salicylic acid, hydrogen peroxide and nitric oxide. Investigations into the mechanisms of cell death versus those of defense pathway activation revealed that the cellular ROS level is an important determinant of the defensive threshold of the cell, which when breached, leads to PCD activation. Interestingly, our findings suggest that the mitochondrion plays a significant role in the activation of defense and death pathways through its ability to both define cellular ROS level and modulate the chemical nature and intensity of a mitochondrial-derived ROS signal. An integrative model which summarizes the role of the mitochondrion, the chemical nature of ROS signal produced, and the impact of the antioxidant network on the decision between life and death is presented. Overall, the concept that the plant can modulate death in response to the severity of the stress seems simple; however, this ability provides the plant with a great deal of flexibility to respond appropriately to an ever changing environment and may represent a basic physiological response to diverse abiotic and biotic stresses.
Students' perceptions of online asynchronous discussion and group learning in graduate distance education courses

This grounded study examined students' experience with two types of interaction in asynchronous online courses: ones in which students engaged in seminar-style discussions (Issue-based) and ones in which students worked together on a common project (Project-Building). Ten students, who had participated in both types of interactions, were interviewed. Qualitative analysis uncovered that in both discussions, themes of student diversity, the asynchronicity of the environment and a sense of community affected the students' experience. In Issue-Based discussions, students' diversity was advantageous as it exposed them to a variety of experiences and perspectives. The asynchronous nature of the environment allowed the students to focus on, and pursue, ideas of personal interest, provided flexibility and facilitated reflection and deeper learning. However, their interactions were not truly collaborative, since there was little impetus for students to develop shared understandings or pursue a common line of inquiry. In Project-Building discussions both diversity and asynchronicity proved to be a negative influence on students' experience as it caused stress and frustration due to difficulties in negotiating meaning and consensus. This frustration was often amplified by a need to complete the project by a particular deadline. As a result, many groups in the Project-Building condition abandoned collaborative work in favour of a "divide-and-conquer" cooperative work approach. From these findings, an extension and elaboration of Murphy's (2004) six-stage model of collaboration is developed. It is further proposed that while the term, "collaboration" is often used to describe the kinds of activities that take place online, most group activities only reach stage 2 or 3 of Murphy's scale. Deeper levels of collaboration can be fostered through the design of group activity structures that minimize, or avoid, the problematic conditions identified in this research. Two such activity structures are outlined.

Keywords: Distance education
Distance education students, Attitudes
Graduate students, Attitudes
Computer conferencing in education
Group work in education
Methods for inclusion: employing think aloud protocols in software usability studies with individuals who are deaf

This thesis explores the viability of collecting gestural protocols from study participants who are deaf using the think aloud protocol method. Two studies were carried out: (1) a comparative study and (2) a usability case study. In the comparative study, gestural and verbal protocols were collected from deaf and hearing participants respectively while playing a game of computer solitaire. The protocols were compared and the viability of gestural TAP (GTAP) as a usability evaluation method was considered. In the usability case study, the GTAP method and outcomes were assessed further. As expected, no differences were found between verbal protocols and gestural protocols and deaf participants were able to sign their thoughts while manipulating a computer interface. Also, the quality, content and quantity of gestural protocols collected were not noticeably or statistically different from their verbal counterparts. The results of the solitaire task and the law video usability study support the viability of gestural TAP as a usability evaluation method and provided additional evidence that the cognitive systems used to produce successful verbal protocols in people who are hearing seem to work similarly in people who speak with gestures. The challenges for adapting the TAP method for gestural language related to how the data was collected and not to the data or its analysis. Methods for collecting protocols using GTAP and considerations for analysing gestural protocols are discussed.

Keywords: Deaf
Computer software
Gesture
Sign language
The characteristics of teacher expertise in elementary school inclusive classrooms

This thesis is an examination of the characteristics of teacher expertise in inclusive elementary school classrooms. A series of six case studies are presented that provide a focused look at selected teachers and their inclusive classrooms. These six teachers stand out from other teachers, and this inquiry is aimed at finding out what it is that makes them unique. The teachers were selected because of their high scores on two separate measures, one of teacher practice and one of teacher beliefs. The participants were observed in their classrooms, then participated in a prompted recall interview, the Teacher Experience Interview. The interview focused on observed interactions with students with exceptional needs and/or who are at-risk for school failure, as well as specific beliefs that the teachers held and influences they nominated as significant in their backgrounds. Utilizing a grounded theory approach, results of the analysis indicate that these teachers employ a variety of instructional strategies, focusing on engaging all students in the learning process. Relationships between teachers and their students are also identified as a significant part of how the participant teachers see their role. The participants also share formative experiences with students with exceptional needs and/or who are at-risk for school failure prior to entering teaching. Characteristics of teacher expertise in inclusive classrooms are seen as a combination of teacher practices and beliefs and attitudes that exemplify an ethic of care and build resilience in students, particularly those with exceptional needs and/or who are at risk for school failure.
Ionic selectivity and regulation of maitotoxin-activated nonselective cation channels in rat cardiac myocytes

Maitotoxin (MTX) reversibly activated a nonselective cation channel in ventricular rat myocytes, which had an ion selectivity sequence of K + > Rb+ > Cs+ > Na+ = Li+ > NMDG. MTX-activated currents (IMTX) were impermeable to divalent cations, although current amplitudes were augmented by Ca 2+ and Sr2+ but not Ba2+. Pre-treatment of the cells with trypsin (20 μg ml−1) or internal DTT (10 mM) abolished IMTX. The protein tyrosine kinase (PTK) inhibitor, genistein (10–100 μM), nullified the effect of the toxin, whilst its inactive analogue, daidzein (100 μM), had no effect. IMTX was not blocked by another PTK inhibitor, lavendustin A, suggesting genistein may mediate its effects via a tyrosine kinase-independent manner. Depleting intracellular ATP prevented the appearance of IMTX. IMTX was elicited in the presence of either intracellular ATP or the ATP hydrolysis-resistant analogue, AMP-PNP. In summary, activation of IMTX in cardiac myocytes is sensitive to proteolysis and dependent on intracellular disulfide bonds, ATP via hydrolysis- and phosphorylation-independent manner.
Pediatric posterior fossa tumors: Preoperative predictors of chronic hydrocephalus

Introduction. In pediatric posterior fossa tumor patients, an unspecified 30% develop chronic hydrocephalus. Recent literature suggests that preoperative CSF diversion diminishes morbidity and cost. A preoperative prediction score of hydrocephalus could tailor and optimize these children's treatments. Methods. A literature search and formal qualitative interviews of experts were used to generate potential predictors. Data from 343 Toronto patients were used to construct the prediction score. Data from 111 Vancouver patients were used to validate the model. Discussion. This score will allow improved patient counseling, surgical planning, and identifies patients at high risk, who selectively, might be exposed to the risks of pre operative CSF diversion to improve outcome. Results. Significant risk factors and their prediction (score) were: age
BMP-induced heterotopic bone formation in Fetuin-deficient mice

Purpose. It is difficult to regulate the extent and shape of BMP-induced bone. Fetuin, known as α2-HS-glycoprotein (Ahsg), is a serum and bone glycoprotein, which binds to TGFβ and BMP cytokines. It likely acts as a decoy receptor for TGFβ, and BMP. We hypothesized that BMP-induced osteogenesis in vivo, would be enhanced in Ahsg-deficient animals. Objectives. To demonstrate whether or not BMP-induced osteogenesis would be altered in Ahsg-deficient ( Ahsg−/−) mice as compared to either heterozygous (Ahsg+/−) or wild-type (Ahsg +/+) mice. Methods. Twelve mice from each group received 5 mg of human native BMP implanted into the hindquarter muscle. Animals were sacrificed after 4 weeks and analyzed for the extent of osteogenesis. Results. Parameters of osteogenesis were found to be significantly increased in Ahsg-deficient mice. Conclusions . Ahsg appears to downregulate BMP-induced bone formation in vivo, and could potentially be used to control BMP-induced osteogenesis in a clinical setting.
The place of art music in Edwardian England: Issues of class, function, and taste

The Edwardian era was a pivotal point in the attempted shift of placement, in art music as well as in other cultural endeavours, away from the elevated climes of the gentlemanly elite and into the more every-day realm of the Common Man. The goals of this study are to highlight political, economic, and social elements of nineteenth-century England that assist in an understanding of the musical environment and aspirations in the period leading up to the First World War, and to look at the delineation of a place for art music with reference to the ideals and values of the cultural elite and the members of the music community who promoted it. This study is organized to move from those topics of more general socio-cultural application to those of more specifically musical application. The first three chapters look at aspects of English social, political and economic history that had a bearing on the development, over the nineteenth century, of the attitudes of the English of various class sectors towards music in private and public life (focusing on musical activity in London), on the segregation of art music from commercial popular music, and on the elevation of orchestral music to the pinnacle of the hierarchy of music by the end of the century. The last three chapters deal more specifically with issues associated with the profession of music in the years leading up to and including the so-called "musical renaissance." The concept of how the musical renaissance was institutionalized and encouraged by the dominant (professional) class, parallel to other contemporaneous social and cultural constructs, is considered as part of the general trend towards modernization, professional development, and nationalization. The debate within the professional ranks over the nature and role of national music is related to the overall endeavour by the dominant class to establish a single national cultural identity of Englishness, through the invention of tradition and the invocation of a shared heritage. Finally, specific issues concerning the place of music in the Edwardian era are canvassed, by reference to the personal ideologies and music of Parry, Elgar and Vaughan Williams.
Abused women's experiences of a 7-day wilderness trip: exploring processes of empowerment

The purpose of the present study was to better understand the meaning and role that therapeutic wilderness trips can have in the lives of women who have been abused. Central questions guiding the inquiry included: how do women who have been abused experience a particular 7-day wilderness trip and what contributes to women's healing and empowerment? Using a qualitative methodology, these and related questions were explored with 9 participants who had experienced various forms of abuse. Results describe how participants have been affected by abuse, activities that have helped women deal with the adverse effects, and experiences of the wilderness trip. Most participants benefited from the trip such that they were able to live with more freedom from the adverse effects of abuse. Experiences on the trip that facilitated positive outcomes included: physical and social engagement, and a context of safety, support, fun, wellness, and being outdoors in the wilderness.

Keywords: Abused women
Adventure therapy
Wilderness survival, Psychological aspects
Genetic analyses of natural variation in Drosophila melanogaster

A major challenge for modern Biology involves the elucidation of the genetic and molecular mechanisms that underlie natural variation in behavioural phenotypes. In the fruit fly, Drosophila melanogaster, many genes that influence behaviours have been identified, primarily as a result of their mutant effects. However, the contributions of variation in these genes to naturally maintained behavioural variation is often unknown. The identification of genetic variation effecting naturally maintained behavioural variation will provide insight for therapeutic interventions. By resolving and quantifying the plasticity or flexibility present and maintained in the molecular cascades that regulate behavioural responses in natural populations, researchers will identify therapeutic limits within which it may be possible to manipulate the systems while potentially minimizing undesirable side effects. Toward enhancing the understanding of the genetic bases of natural behavioural variation, this thesis presents research on three different phenotypes, each of which have been previously described to different degrees. The first study involves an investigation meant to further resolve the molecular mechanism by which allelic variation in the for gene effects differences in foraging behaviours. The second study presents efforts to identify the genetic basis for variation in pupation position, a well-studied behaviour with known fitness consequences, and presents an initial description of associated variation in wandering behaviours. The third study investigates pupation behaviour from a more physiological perspective. In this study it was observed that larvae selected for high NaCl tolerance, which may have altered osmoregulatory abilities, pupate significantly farther from their growth media than do wild-type larvae. As a result, an effort was made to map the genetic factors effecting natural variation in NaCl tolerance. Taken as a whole, this work has the potential for extending the mechanistic understanding of complex interactions between genetic and environmental effects and the resultant behavioural responses.
A direct comparison of memory encoding and retrieval using magnetoencephalography

A fundamental aim in memory research is to understand the relationship between memory encoding and retrieval. Recent neuroimaging studies suggest that many of the same brain regions are involved in both encoding and retrieval. This study sought to examine whether there are differences in the extent to which these neural substrates are engaged and, whether there are differences in their underlying temporal dynamics. Participants performed an intentional encoding task followed immediately by a recognition test while their brain activity was measured using magnetoencephalography (MEG). Both encoding and retrieval elicited peak activity from the occipital, parietal and medial temporal lobe at around 100-250 ms. This suggests that memory processes depend on distinct brain regions operating in a parallel manner. It was also found that neural activity in posterior brain regions was significantly less during successful retrieval. This indicates that successful memory formation can lead to subsequent enhancement of neural efficiency.