VictorJuiz/thesis huggingface dataset:
Regulation of metabolic effects in L6 muscle cells by sulfonylureas and the protein tyrosine phosphatase inhibitors vanadate and pervanadate

Non-insulin-dependent or Type II diabetes mellitus (NIDDM) is a disease characterized by insulin deficiency and insulin resistance. Treatment is directed at improving either one or both of these abnormalities. The most commonly used pharmacological agents to treat NIDDM are the sulfonylurea drugs. A controversial and unanswered question about sulfonylureas is whether they possess any direct actions on peripheral insulin target tissues. The effects of gliclazide and glyburide on glucose uptake in L6 skeletal muscle cells, a model of a major insulin target tissue, were investigated. These studies demonstrate that gliclazide and glyburide similarly increase glucose transport into L6 cells which is associated with an increase in total cellular and plasma membrane GLUT1 glucose transporter levels. The mechanism appears to involve stabilization of GLUT1 at the plasma membrane. Since many patients with NIDDM do not respond to currently available oral hypoglycemic agents, a great deal of research into understanding insulin action and resistance and the development of novel agents is ongoing. Vanadium compounds ape protein tyrosine phosphatase inhibitors which have been useful probes to study insulin signalling and have also been proposed as potential therapeutic agents. The effects of the vanadium compounds sodium orthovanadate and pervanadate on glucose and amino acid transport and their mechanism of action were investigated. The results demonstrate that vanadate and pervanadate mimic insulin to stimulate glucose transport in L6 cells but inhibit amino acid (MeAIB) transport by the insulin-sensitive system A transporter. The data suggest that this inhibition may be mediated by inhibition of a protein tyrosine phosphatase. It was also found that the stimulation of glucose transport by vanadate and pervanadate is mediated by a signaling pathway that differs from that of insulin and importantly is independent of PI 3-kinase, the enzyme involved in the insulin signalling of glucose transport. These findings contribute new knowledge to our understanding of the effects and mechanisms of action of the oral hypoglycemic sulfonylurea drugs and vanadium compounds. Taken together the results support the continued use of sulfonylureas and the potential use of vanadium compounds in disease associated with insulin resistance.
Engagement with text through social interaction

This study explores the issue of engagement with text through social interaction. It is a qualitative research project consistent with the practical and theoretical tenets of action research. It stems from a social constructivist view toward learning. In this investigation, the school's ESL teacher, who is the teacher-researcher, works in collaboration with the classroom teacher of a Grade 4 class. The central question of the study is: How does collaborative thinking facilitate engagement with text? The question is examined through two teaching strategies: literature circles and classroom drama. The study is an exploration of stated assumptions related to student learning and inquiry. Themes that emerged from the study include: questioning, personal identification with story characters, personal experience related to text, intertextuality, awareness of author and illustrator, collaborative thinking, language power, and quality of engagement with text. Implications from the study indicate that students and teachers benefit from opportunities for collaborative learning and talking about text. In order to maintain anonymity throughout the study, the students and classroom teacher chose names from children's literature or from the authors of children's literature.
Plant distribution and colonization in extreme polar deserts, Ellesmere Island, Canada

Polar desert vegetation (with usually less than 5% vascular plant cover) represents 15.1% of the arctic tundra biome area, yet its composition and distribution are poorly known. The Canadian High Arctic contains 75.6% of the polar deserts of the world. They are characterized by very cold and extremely short growing seasons and minimal summer precipitation. This thesis investigates the vascular species richness and distribution based on the survey of 82 sites on central Ellesmere Island, Canada. In addition, it addresses fundamental questions regarding three major variables potentially limiting plant community development: the availability of 'safe sites'; the abundance of viable seeds; and the limited time for plant establishment since the site's deglaciation. The minimum sampling area of this sparse vegetation was measured to be 10-25 m$\sp2.$ Vascular species richness ranged from 2-22. Four key vascular species: Saxifraga oppositifolia, Papaver radicatum, Draba subcapitata and Draba corymbosa occurred on 60-100% of the sites. Some species were restricted to a specific substrate, either granite or carbonate. Bryophyte and lichen cover was frequently $<$0.1% and $<$5% respectively. Environmental variables measured explained a large portion of the vegetation variation (more than 67%). Elevation was the most important variable. Vegetation on low elevation sites was more abundant and diverse. Four vegetation groupings reflecting plant abundance, plant diversity and substrate type were distinguished with a two-way indicator species analysis (TWINSPAN). Plant distribution on a dolomitic plateau was contagious and plants tended to grow near protective boulders. Along two altitudinal gradients, flower buds were produced almost every year by Papaver radicatum, but flower and fruit production varied depending on site conditions and yearly summer climate. Germinable seed banks were found even in extremely poor sites. This study demonstrates the diversity of polar deserts in central Ellesmere Island. Reproduction by seeds on such sites is common although its success depends on local climate which varies greatly from year to year. Recruitment of new seedlings is rare although vacant 'safe sites' and seeds are available. Ground surface dessication may partly interfere with this process. The findings of this work suggest that recruitment is restricted to short periods when conditions are more favourable.
Getting back to the garden, rethinking child welfare in Uganda

This study examines the attempts of the Ugandan government to enunciate and implement a policy of child welfare that is community based. The study analyses child care practices in traditional communities, and highlights the disruptions caused by external influences, including the imposition of a colonial system. It also considers important impacts, dictatorships, civil wars, economic problems, and the AIDS epidemic. The implementation of a new approach to child welfare, one oriented to a conception that looks back to a time when Ugandan society was community based, is explored. The dilemmas within the attempt to implement such a policy are also discussed. The analysis suggests that the spirit of communalism still exists in Uganda with regard to child care. Nevertheless, it also appreciates that communities are faced with many problems that might undermine it. Paramount among these are the AIDS epidemic and lack of resources. As well, western ideas and concepts such as gender equality and children's rights might influence attempts to re-establish traditional forms of child welfare. Thus, considering that many changes have occurred in communities, the traditional context has been altered, and some traditional communal practices might not be useful or relevant in the modern context. Nonetheless, there are positive practices that can be revisited and strengthened. It is the view of this study, therefore, that the garden we wish to reclaim will need different methods of cultivation from those used in the traditional garden. Consequently, the garden will be different from the traditional one.
The efficacy and effectiveness of antidepressants in elderly depressed patients, meta-analytic and pharmacoepidemiological methodologies for the assessment of antidepressant pharmacotherapy

Objective. The efficacy and effectiveness of antidepressants in depressed elderly patients is unclear. Methods. Meta-analyses (random effects model) aggregated published literature of randomized controlled trials for atypical antidepressants (ATYPs), reversible inhibitors of monoamine oxidase A (RIMAs), selective serotonin reuptake inhibitors (SSRIs), tricyclic anti-depressants (TCAs) and placebo in patients $\ge$60 years old for $\ge$4 weeks. Outcome measures included efficacy, safety and dropout. The effectiveness of antidepressants was examined with a prospective practice-based observational study (1991-1994), rationale for prescribing, survival analysis (Kaplan Meier; Cox Regression), adverse event profile and medication changes. Consecutive outpatients at least 65 years of age, diagnosis of depression and prescribed antidepressant medications were included. Results. Overall meta-analyses, for ATYP indicated that 33.4% (Number of studies = 2, Number of patients = 30; (CI95%: 5.2% to 61.7%)) responded to treatment, 37.5% (12, 280; (29.1% to 45.9%)) reported adverse events and 11.2% (16, 374; (6.9% to 15.6%)) dropped out, respectively. For RIMAs, no efficacy results; 57.7% (4, 106; (35.7% to 79.7%)) and 27.1% (3, 96; ($-$1.2% to 55.5%)). For SSRIs, 54.8% (9, 624; (43.1% to 66.4%)); 59.1% (10, 501; (44.2% to 74.0%)) and 18.5% (20, 1395, (14.3% to 22.6%)). For the TCA, 67.0% (5, 200; (57.4% to 76.7%)); 60.3% (8, 276; (31.3% to 89.2%)) and 23.2% (20, 902; (17.0% to 29.4%)). For placebo, 27.2% (2, 302; (22.1% to 32.2%)); 39.6% (4, 111; (6.9% to 72.4%)) and 25.6% (6, 476, (11.5% to 39.7%)). Comparative meta-analyses indicated no significant differences between antidepressants except for ATYP minus SSRI efficacy $-$36.9% (CI95%: $-$65.4% to $-$8.4%, p = 0.01). For the effectiveness evaluation, 259 patients were seen over 2922 visits (mean age $\pm$ SD 75.1 $\pm$ 6.1 years). "Physician knows medication, feels comfortable prescribing it" was the most common rationale for prescribing. 80% of patients did not have depressive symptoms after four weeks of antidepressant treatment, whereas, 70% had depressive symptoms after 6 months and 60% after 2 years. There was no statistical difference in survival time to depressive symptoms between antidepressant classes. 76.0% of visits reported adverse events (mean = 2.7 $\pm$ 1.8). All classes reported similar adverse event profiles. 74.9% study patients had 1223 medication changes. TCAs, MAOI/RIMAs and ATYPs were most commonly changed to SSRIs. Conclusions. There is little advantage for prescribing one antidepressant class over another, acutely or chronically.
Evaluation of Gaussian processes and other methods for non-linear regression

This thesis develops two Bayesian learning methods relying on Gaussian processes and a rigorous statistical approach for evaluating such methods. In these experimental designs the sources of uncertainty in the estimated generalisation performances due to both variation in training and test sets are accounted for. The framework allows for estimation of generalisation performance as well as statistical tests of significance for pairwise comparisons. Two experimental designs are recommended and supported by the DELVE software environment. Two new non-parametric Bayesian learning methods relying on Gaussian process priors over functions are developed. These priors are controlled by hyperparameters which set the characteristic length scale for each input dimension. In the simplest method, these parameters are fit from the data using optimization. In the second, fully Bayesian method, a Markov chain Monte Carlo technique is used to integrate over the hyperparameters. One advantage of these Gaussian process methods is that the priors and hyperparameters of the trained models are easy to interpret. The Gaussian process methods are benchmarked against several other methods, on regression tasks using both real data and data generated from realistic simulations. The experiments show that small datasets are unsuitable for benchmarking purposes because the uncertainties in performance measurements are large. A second set of experiments provide strong evidence that the bagging procedure is advantageous for the Multivariate Adaptive Regression Splines (MARS) method. The simulated datasets have controlled characteristics which make them useful for understanding the relationship between properties of the dataset and the performance of different methods. The dependency of the performance on available computation time is also investigated. It is shown that a Bayesian approach to learning in multi-layer perceptron neural networks achieves better performance than the commonly used early stopping procedure, even for reasonably short amounts of computation time. The Gaussian process methods are shown to consistently outperform the more conventional methods.
Responses to Byron in the works of three nineteenth-century novelists, Edward Bulwer, Charles Dickens and Charlotte Brontë

Andrew Elfenbein's Byron and the Victorians (1995) is a full-length account of Victorian response to Byron and Byronism. This thesis builds upon his work by examining how three nineteenth-century novelists, Edward Bulwer, Charles Dickens and Charlotte Bronte, responded to Byron in their fiction. Edward Bulwer's late Regency Bildungsroman, Pelham, The Adventures of a Gentleman (1828) is an example of Byron's pre-Victorian reception which shows how one Regency novelist inscribed Byronic figures in his fiction. Pelham also dramatizes the problematic conflict between male infatuation with Byronic figures and the Bildungsroman impulse. Charles Dickens responded to Byron and Byronism more than two decades later in his Victorian Bildungsroman, David Copperfield (1849/50). Like the later Bulwer, who was critical of Byronism in Ernest Maltravers (1837) and its sequel, Alice (1838), Dickens showed an ironic, sometimes satirical detachment from Byronism. David Copperfield, however, also reveals Dickens' sense of the disempowering paralysis caused by a lingering nostalgic attachment to Byronic figures. Charlotte Bronte responded much more directly to Byron than her male contemporaries. Writing satire, not romance, she extensively re-worked Byron's The Corsair in Shirley (1849), treating her Byronic "hero" with a cold detachment that was characteristic of other women novelists such as Mary Shelley and George Eliot. Shirley, with its Monday morning realism, is at once a Childe Harold-like lament and a Thackerayean satire on an age in which heroism seemed impossible.
Modeling biological iron

The first neutral four-coordinate selenolato iron(II) complexes and the first four-coordinate iron(II) 1-methylimidazole (1-MeIm) complexes Fe(Se-2,6-i-$\rm Pr\sb2C\sb6H\sb3)\sb2(L)\sb2$ (L = PMe$\sb2$Ph, 1; L$\sb2$ = depe, 2), Fe(E-2,6-i-$\rm Pr\sb2C\sb6H\sb3)\sb2(1-MeIm)\sb2$ (3, E = S; 4, E = Se), and Fe(E-2,4,6-Me3C$\rm\sb6H\sb3)\sb2$(1-MeIm)2 (E = S, 5; E = Se, 6) are prepared by metathesis of chloride ligands of iron(II) chloride with selenolate or thiolate in the presence of two equiv. of the neutral ligand. The complexes are oxygen sensitive and have room temperature magnetic moment of 5 $\mu\sb{\rm B}$ for both 1 and 2 and 4.5 $\mu\sb{\rm B}$ for 3 and 4. The proton NMR spectra exhibit paramagnetic shifts and broadening associated with the unpaired electron density at the iron(II) center. These complexes exhibit irreversible cyclic voltammetry in THF solution. The Mossbauer spectrum of 1 is also reported. Single crystal X-ray diffraction studies of complexes 1-6 reveal a distorted tetrahedral coordination geometry about the iron centers for all complexes. A catalytic cycle involving iron hydride and dihydrogen complexes is proposed as an alternative to the nickel-based mechanisms for nickel-iron hydrogenases. This mechanism is consistent with the available experimental evidence as well as predicted iron(III) reduction potentials calculated using the ligand additivity method. The hydridocyano iron(II) complexes trans-Fe(H)(CN)(L)$\sb2$ (L = depe, dppe) are protonated to produce trans- (Fe(H$\sb2$)(CN)(depe)$\sb2$) (BF$\sb4)$, 3, and trans- (Fe(H$\sb2$)(CNH)-(dppe)$\sb2$) $\rm (CF\sb3SO\sb3)$, 4, and doubly protonated to produce trans- (Fe(H$\sb2$)(CNH)(L)$\sb2$) (X)$\sb2$ (L = depe, X = BF$\sb4$, 6; L = dppe, X = $\rm CF\sb3SO\sb3,$ 7). Complex 7 is deprotonated by Et$\sb2$O to produce trans- (Fe(H$\sb2$)(CN)(dppe)$\sb2$) (CF$\sb3$SO$\sb3$), 5, which is stable in the solid state but in $\rm CH\sb2Cl\sb2$ solution isomerizes to trans- (Fe(H)(CNH)(dppe)$\sb2$) $\rm (CF\sb3SO\sb3)$, 4. The H-H separations using the $T\sb1$ method are all in the range of 0.84 to 0.87 A. These values agree with the separations of 0.87 to 0.89 A calculated by the measured $\sp1J\sb{\rm HD}$ values in the range of 31.6-32.7 Hz. A number of solutions containing iron(II) and iron(III) with a variety of potential ligands are tested for their ability to hydrolyze acetonitrile as potential models of nitrile hydratase. The ligands tested include 2-mercapto-1-methylimidazole, 2-mercaptopyridine, 2-mercaptopyrimidine, 1-methylimidazole, pyridine and imidazole. Acetamide is produced by a majority of the iron containing solutions.
Connections on the professional knowledge landscape, a narrative inquiry into the experience of a beginning teacher, her administrator and a teacher/researcher

This is a narrative study of the experience of a beginning teacher and her administrator during her first four years of teaching. The study is set within the context of the professional lives of three women, the new teacher, the principal and the teacher/researcher who occupy different positions on the professional knowledge landscape. It focusses, in retrospect, on the new teacher's entry to the teaching profession. Within this context, we have worked collaboratively across two particular school settings to explore the nature and meaning of this experience, highlighting the role of the principal in the growth and development of the novice teacher. The inquiry has explored, from three perspectives, the ways in which our lives connected and shaped each other's during the new teacher's first years in the profession. While keeping the experience of the new teacher central to the inquiry, the professional knowledge contexts of all triad members have emerged through the research process. The study is composed of interacting levels of narrative accounts which appear in various literary forms, stories, poems, letters, memos, dialogues and reflections reflecting the language of school communication. This collection of school stories forms the heart of the thesis. As the teacher/researcher I draw from these reconstructed stories and accounts of experience and describe how, through the research process, both the new teacher and the administrator came to new understandings about beginnings in teaching. I illustrate how stories of expectation, cover stories and stories of ownership reveal insights into the qualitatively different professional knowledge landscapes of the participants. Through the research process we engaged in conversations of practice which bridged these landscapes and enhanced our understanding of the multiple contexts of teaching and administration. The study points to the importance of collaborative research as professional development, as a place for professional dialogue and reflection. Further, this narrative inquiry highlights the importance of story as a viable mode of knowing in teacher development research. By reconstructing, contextualizing and analyzing our teacher stories, this study has evoked credible images of the lived experience of school people.
Faculty's implicit theories of academic work

This study investigated how faculty at Canadian universities conceptualize their various professorial roles. These conceptualizations were considered their implicit theories of academic work. Implicit theories were explored using Kelly's (1955) theory of personal constructs. The theory suggests that experience is a function of people's self-constructed knowledge. Two groups of faculty were considered, those that qualify as experienced, and those that are less experienced. The research followed Kelly's (1955) repertory grid technique. The elements in the grid were activities representative of what faculty do, and the constructs were interpretations faculty use to discriminate among these activities. Both elements and constructs were determined by faculty in research phases one to three. In the final research phase, the standardized repertory grid was administered to a total of 88 faculty. Each grid was analyzed individually. The two groups were then compared using both inferential as well as non-inferential measures. Three research questions were explored: first, do experienced faculty, as compared to less experienced faculty, hold more complex implicit theories of academic work; second, do the implicit theories of experienced faculty show a higher level of integration of the teaching function; and third, are there dimensions of academic work underlying these implicit theories that are different from the traditional division into research, teaching and service, and are these dimensions different for the two groups. In order to address the first and second research question, t-tests for independent groups were conducted. Significant differences were found on some variables, suggesting that experienced faculty have a more integrated view of academic work. The third research question was explored using descriptive statistics. The data from both groups were first aggregated to form a consensus grid for each group. Each of the two resulting grids was then subjected to a principal component factor analysis. The two group grids differed in terms of number and interpretation of factors, and variance accounted for by the first factor. Both groups conceptualized academic work differently from the literature. Experienced faculty seemed to perceive a link between learning about one's discipline, learning about teaching, and collaboration, suggesting the need for a reconceptualization of scholarship. While the two groups, overall, agreed in terms of the relative importance of the activities, they agreed the most on the research items and disagreed the most on the teaching items.