VictorJuiz/thesis huggingface dataset:
Cellular effects of 9-aminocamptothecin when combined with other chemotherapeutic agents

9-Aminocamptothecin (9-AC) is a water insoluble camptothecin derivative presently undergoing clinical evaluation. Camptothecins are inhibitors of topoisomerase I, a nuclear enzyme involved in DNA transcription and replication. Despite promising pre-clinical and clinical results, 9-AC will probably need to be combined with other chemotherapeutic agents in order to maximize its clinical potential. This thesis describes the effects of combining 9-AC with two of the most widely used chemotherapeutic agents, 5-fluorouracil (5-FU) and cisplatin, in human colon (HT-29), breast (MCF-7) and bladder (MGH-U1) cancer cell lines. Cytotoxicity was evaluated by clonogenic assay and synergism and antagonism were determined by the combination index. The mechanisms contributing to cytotoxicity were further evaluated using flow cytometry and the comet assay for single stranded DNA damage. Combinations of 9-AC and 5-FU at the IC$\sb{50}$ concentration were antagonistic while at the IC$\sb{90}$ concentration synergy was seen in 2/3 cell lines when the drugs were given concurrently. The cell cycle perturbations and single stranded DNA damage produced by 9-AC and 5-FU depended on the cell line, dose and the sequence of drug administration. Combinations of 9-AC and cisplatin were synergistic in all cell lines at the IC $\sb{90}$ concentration and the sequence of administration did not influence synergy. IC$\sb{90}$ combinations of 9-AC and cisplatin resulted in an accumulation of cells in G$\sb2$/M-phase (although to a lesser degree than seen with 9-AC alone) and produced the greatest amount of single stranded DNA damage.
The thermodynamic behavior of magnetite in non-ferrous smelting

The problems of magnetite build up have plagued the non-ferrous pyrometallurgical industry for many years. Traditionally, solutions to this problem were brought about add-hoc, as a means of survival, and not necessarily based on rigorous fundamental work. Until now, no comprehensive fundamental studies were available, in the area of nickel pyrometallurgy, which addressed the thermodynamic principles and how the pertinent factors such as temperature, oxygen and sulfur pressure and activities of iron and magnetite influenced the age old problems of magnetite saturation. One of the main objectives of this study was to provide a sound investigation and subsequent analysis, obeying the guiding principles of thermodynamics (phase rule) in order to understand the mechanisms behind magnetite saturation during nickel smelting. By fulfilling this goal, methods which could be used to control the behavior of magnetite as well as obtaining metallurgical benefits would naturally follow. Of perhaps equal and even more significance, was the manner in which these experimental data and fundamental understanding could be applied on an industrial level. In order to fulfill these objectives a series of equilibration studies were performed in the systems matte-gas and matte-slag (silica saturation)-gas. The thermodynamic variables of temperature, sulfur and oxygen pressure and matte grade were examined and their relationships to the magnetite activity were defined. In general, a lower sulfur pressure and higher temperature operation was proven to enhance the metallurgical benefits of nickel smelting by decreasing the magnetite activity. Comparison of actual industrial data, with those of this experimental study indicated that even by incorporating these data into theoretical process models (heat and material balances) no matter how reliable they may be, the real situations may end up radically different to those predicted from the models. It should be recognized that these types of studies only provide a guideline which can be used to pursue larger scale testwork in an attempt to prove out real and attainable benefits. Without these types of studies to form the basis for development, a clear direction and significant progress would never be possible.
Uniqueness of the visual processing disabilities in children with nonverbal learning disabilities and their relationship to performance in arithmetic

Visual processing difficulties have been described as a core problem of children with nonverbal learning disabilities (NLD; Rourke, 1989), but the specific nature of these difficulties has received little systematic investigation. The younger the age at which these kinds of difficulties are identified, the better the opportunity for successful intervention (Rourke, 1989). The present study systematically compared the simple and complex visuoperceptual and visual-spatial abilities of 6-year-old boys with NLD ('n' = 13) to a matched control group of boys with other learning disabilities (CLD) and to normative scores. A profile of strong average abilities on a simple discrimination task but relative visual-spatial weaknesses was unique to the NLD group, as was significantly poorer ('p' <= 5.01) performance on the mom complex mental rotation task. The visual processing abilities of children with NLD were positively associated with their arithmetic scores, but no significant correlations were found for the CLD group.
Kidney transplantation in elderly patients with end-stage renal disease

Transplantation compared to dialysis offers superior life-expectancy and quality of life for young patients with renal failure. However the initial risks of mortality and morbidity are high, especially with increasing age. This study uses a decision analysis model to evaluate the costs and benefits of kidney transplantation versus continued dialysis for an older patient with renal failure. A decision analysis framework was built using SMLTREE software. The base case focused on a 65 year old white, non-diabetic male. Probability, utility and life expectancy data were obtained from the literature and renal registries. Life-expectancy on dialysis was 2.9 quality-adjusted years at a cost of $338,335. Life expectancy with transplantation was 4.2 quality-adjusted years at a cost of \$249,440. The cost-effectiveness analysis showed a dominant situation. Sensitivity analysis revealed that the results were stable across most variables. Transplantation is cost-effective when compared to dialysis for older individuals, suggesting that it should be offered more frequently to well-selected patients.
The cloning and characterization of unc-130, a gene required for dorsal-ventral axon guidance and DTC migrations in Caenorhabditis elegans

Migrating cells and axonal growth cones require directional information in order to guide them to their destinations. Although many molecules that help guide migrations have now been isolated, many aspects of the guidance of cellular migrations remain to be elucidated. In particular, many extracellular ligands and their respective receptors have been shown to provide cues that direct migrations. However, little is known about the control of expression of these cues or intracellular signaling events downstream of their receptors. It is also likely that other guidance cues remain undiscovered. In order to better understand the mechanisms that govern the guidance of migrating cells and axonal growth cones, I have taken a genetic approach, cloning a gene whose disruption causes phenotypes similar to those caused by mutations in genes known to affect guidance. I have cloned and characterized ' unc-130', which encodes a Forkhead transcription factor required for the guidance of dorso-ventral migrations in 'C. elegans'. The predominant role of 'unc-130' in guidance is to repress transcription of 'unc-129' cell-autonomously in ventral muscle. This, in turn, allows 'unc-129' to perform its normal functions in guidance (Colavita, et al, 1998). In addition to a role in guidance, 'unc-130 ' is also required during embryogenesis and male tail ray morphogenesis, where the phenotypes of 'unc-130' mutants suggest a role in specifying the fates of sister cells at several points within the male tail ray lineage. Genetic interactions between 'unc-130' and other genes confirm that several partially redundant genetic pathways cooperate in order to guide the migration of distal tip cells (DTCs) and axonal growth cones in 'C. elegans'. This helps to explain how the guidance of cellular movements can be highly reproducible. In addition, genetic tests confirm that 'unc-129', which encodes a TGF-ß ligand, does not act via the known conventional type II TGF-ß receptor in ' C. elegans' (Colavita, et al., 1998). Finally, the finding that mutations in 'unc-129' partially suppress the DTC migration defects seen in 'unc-130' mutant backgrounds provides the basis for a screen to identify genes that act in the 'unc-129' pathway. This screen may help determine how 'unc-129' function is mediated.
Journal writing in an elementary math classroom and its effect on students' understanding of decimals

This is an exploratory, action research study of the use of journal writing, focused on four students in a regular grade five math class and their growing understanding of decimals. They were given journal assignments as well as oral and manipulative-based activities during a series of ten, forty minute lessons. Data collection methods included field notes, audio taped student-student and teacher-student interaction, and written journal entries. The findings of the study indicate that students' use of journal writing, in conjunction with other constructivist tools such as manipulative-based activities, significantly improved: their conceptual understanding of decimals; their ability to work through to solutions not previously understood; their ability to consolidate learning initiated through other methods; their awareness of their own understanding; their confidence; and their ownership of their learning. Students' journal entries allowed me, the researcher, to programme and assess students' needs quickly and consistently.
Post-translational modification of p53 protein in response to DNA damage

p53, the tumour suppressor, has potent growth suppressive functions. It is not normally active in cells. It is activated by damage to DNA, or by the presence of activated oncogenes in cells. The mechanism by which p53 protein is activated to reveal its anti-proliferative functions is of importance, and is the theme of this thesis. Post-translational modifications of proteins often signal their activation or inactivation. p53 is known to have several post-translational modifications--phosphorylation, acetylation, glycosylation, poly(ADP)ribosylation and 5.8S rRNA linkage. One aim of the thesis was to identify molecules that would signal DNA damage to p53, to activate its function. The other aim was to identify post-translational modifications on p53 following DNA damage induced by ionizing radiation. Using non-radioactive techniques, this thesis demonstrates that ionizing radiation causes post-translational modifications on p53, especially in the form of multiple phosphorylations and acetylations. The role of DNA-dependent protein kinase in phosphorylating and regulating p53 function was assessed. Though this kinase is activated by damaged DNA, and can phosphorylate p53 'in vitro', this study did not find any evidence of a functional role for DNA-dependent protein kinase in mouse cells. Evidence is also presented to show that phosphorylation of p53 on the cell cycle-regulated cyclin dependent kinase 1 site is constitutive and is not regulated by ionizing radiation.
Identification and characterization of proteins binding to the amino-terminus of the human prion protein

The N-terminus of the human prion protein (PrP) contains a nonapeptide and four related octapeptide repeats of the form P(Q/H)GGG(G/-)WGQ. The presence of additional octapeptide repeats is linked with the development of a dementing and fatal neurodegenerative disease, typically diagnosed as Gerstmann-Sträussler-Scheinker syndrome (GSS). The first 75 amino acids of wild-type human PrP (wtPrP23-98) were used to screen a human brain cDNA library using the yeast two-hybrid system. Retrieved clones were then tested for their ability to bind to an expanded N-terminal construct of PrP containing 8 additional octapeptide repeats (PrPGSS). One clone encoded an almost full-length cDNA of the active subunit of the transglutaminase (TGase) Factor XIII (FXIIIa). Various recombinant molecules of PrP were shown to be 'in vitro' substrates of FXIIIa and another TGase, suggesting that these enzymes might be involved in the pathology of certain amyloidogenic prion diseases.
Resonant forms, architecture in the poetry of Seamus Heaney and Derek Walcott

Architectural images and metaphors frequently appear in the poetry and poetics of Seamus Heaney and Derek Walcott. Architecture, including the vernacular, acts as a means by which both Heaney and Walcott locate their poetry in place. In other, often enigmatic ways, the use of architectural and spatial tropes provide the dynamic terms for exploring temporal issues. This thesis investigates the imaginative process by which each poet reads various examples of architecture in Ireland, the West Indies, and elsewhere. Chapter one explores the poetics of Heaney and Walcott in relation to architecture and creates the basis for a detailed analysis of the poetry. Form emerges as a main concern. They each develop architectural metaphors in their discourse regarding other poets and matters of craft, technique, and voice, but also, in an extended fashion, use it to address broader cultural issues such as language. In chapter two, which traces the notion of 'home' in the poetry, an awareness of architecture as an expressive entity capable of suggesting an almost organic inner life emerges. On occasion, they also reveal a deep ambivalence toward built structures. Chapter three examines their handling of the estate house in the light of traditional representations, leading to a focus on other architectural sites which carry strong historical resonances for each poet. The final chapter continues this inquiry in relation to the presiding notion of memory, the genre of elegy, homage, and the idea of mimetic 'poetic architecture.' Spatial imagery becomes crucially linked with remembrance. In conclusion, architecture in the writing of Heaney and Walcott does not consist merely of static forms, but is responsive to the animating forces of poetic language, continually evoking the fluidity of time.
Nutritional preconditioning and ectomycorrhizal formation of Picea mariana (Mill.) B.S.P. seedlings

Ectomycorrhizal inoculated seedlings may improve forest plantation establishment by enhancing growth and nutrition of newly planted seedlings, but successful nursery colonization of planting stock is often incompatible with conventional fertilization practices because of toxic inhibitive effects. A new cultural technique for seedlings is examined, called "mycorrhizal nutrient loading" that integrates exponential high dose fertilization with ectomycorrhizal association without causing serious inhibition. Containerized black spruce ('Picea mariana' (Mill.) B.S.P.) were inoculated at sowing with 'Hebeloma crustuliniforme' or 'Laccaria bicolor ' and fertilized with a complete nutrient solution conventionally at 12.5 mg N/plant and exponentially at 12.5, 25 or 50 mg N/ plant representing conventional, loading and high loading application rates, respectively. At the end of nursery culture, exponential fertilization significantly stimulated ectomycorrhizal formation at higher rates (49-85%) than those of conventionally fertilized (22-26%) seedlings. Improved ectomycorrhizal colonization, even at high loading rates, was attributed to low initial nutrient additions and lower electrical conductivity levels maintained in the growing media under exponential fertilization. The gradual increase in nutrient delivery enabled the fungi to develop tolerance to high fertilizer inputs. Nutrient loading significantly increased N (51-135%), P (29-45%), and K (13-47%) uptake of seedlings, reflecting progressive luxury consumption of nutrients. Mycorrhizal inoculation further elevated loading efficiency by stimulating plant nutrient uptake of N (9-20%), P (7-12%), and K (4-18%), demonstrating accumulation was more efficient with fungal colonization. Vector nutrient diagnosis revealed marked nutrient dilution under conventional fertilization, but induced steady-state nutrition under exponential fertilization that benefited sustained symbiosis. When outplanted on bioassays retrieved from two contrasting boreal forest (Feathermoss and Hardwood-Alnus) sites in northern Ontario, mycorrhizal nutrient loaded seedlings outperformed conventional seedlings by enhancing dry matter production (45-92%), and increasing N (80-124%), P (89-129%), and K (72-106%) assimilation. The new growth drew on greater internal nutrient reserves built up by both exponential fertilization and mycorrhizal colonization in the nursery. Results were integrated into conceptual models demonstrating interactions of fundamental processes involved in mycorrhizal nutrient loading of trees and their resource utilization after planting in relation to different nutritional regimes. Given the current concern about adequate forest regeneration in Canada, nutrient loading in combination with mycorrhizal inoculation practices provides a potentially effective tool to improve early plantation establishment on boreal sites.
The negative ground of fiction, negation and alterity in Kafka, Beckett, Nabokov

This dissertation begins from a revaluation of the ongoing, although largely covert, significance for modernity of apophatic irony, extending its range from negative theology to the appropriated psychoanalytic term 'denegation': a mode of conscious 'unsaying' operating productively in modern fictional discourse. This focus on a certain species of fictional language and logic centres, around the preeminently modern problem of the self or consciousness, figured in terms of its fictional avatars, the narrative subjects or 'heroes' of Beckett's trilogy, Kafka's 'Das Schloss' and ' Der Prozess', and Nabokov's 'Bend Sinister'. Through close and comparative analyses of these works within this negatively conditioned theoretical framework, the dissertation traces forms of figuration or signification irreducible to any positive, totalizing, hermeneutic recuperation or 'redemption.' The overall movement is toward an elaboration of a 'ground' of modern fictional discourse which is commensurate with the negativity--or 'denegativity'--grounding the self-other relation, as epitomized in these novels. This present absence at the 'heart' of the subject is manifest as a literary effect through the productivity of memory, itself--paradoxically--a 'product' of the discourse. The final thrust of the dissertation is to emphasize the significance of the other for this subjectivity: the alterity from 'outside' the discourse which conditions the selfs 'coming into being.'
The effect of exercise on skeletal muscle morphology in an experimental model of acute congestive heart failure

Skeletal muscle fiber-capillary morphology was investigated in four groups of 12-14 weeks old rats: myocardial infarct exercise (IE; n = 6), myocardial infarct sedentary (IS; n = 5), sham exercise (SE; n = 5), and sham sedentary (SS; n = 5). Myocardial infarct (MI) was induced by ligation of the left anterior descending (LAD) coronary artery. All MI rats were allowed a 35 day healing time before exercising. Exercise training for 6 weeks involved swimming at 5 min/day and increasing 5min/day until the rats were swimming continuously for 40 minutes 5 days/week. The plantaris muscle was sectioned and stained for assessment of muscle-capillary morphometrics for both type I and II fibers. Multiple pairwise comparisons was done by two way ANOVA. All statistical analysis where p < 0.05 are considered to be significant. Changes in muscle fiber size were assessed by fiber area (FA) and perimeter (P). Capillary indices were measured by capillary contacts (CC) and individual capillary-to-fiber ratio (C:Fi) by pairwise comparisons among the four groups. (Abstract shortened by UMI.)
A family of randomized algorithms for list accessing

Sequential lists are a frequently used data structure for implementing dictionaries. Recently, self-organizing sequential lists have been proposed for "engines" in efficient data compression algorithms. In this thesis, we investigate the problem of 'list accessing' from the perspective of 'competitive analysis'. We present ' Markov-Move-To-Front', a randomized family of algorithms, whose random choices are based on the elegant and well-studied stochastic model of Markov chains. The family includes as members well known algorithms such as ' Move-To-Front, Counter', and 'Random-Reset'. First we analyze 'Markov-Move-To-Front' in the standard model, and present upper and lower bounds. Then we apply the bounds to particular members of the family. As a result, we get a max{2,<math> <f> <fr><nu>1</nu><de>p</de></fr></f> </math>} upper bound for 'Random-Move-To-Front'('p'), which is, to our knowledge, the first upper bound for this algorithm. Subsequently, we apply the lower bound to the best member of the Random-Reset family for the standard model, and show that it matches the upper bound given by Reingold, Westbrook, and Sleator. Finally, we analyze 'Markov-Move-To-Front' in the ' Pd' model, and prove upper and lower bounds. Again, we apply the bounds to 'Random-Move-To-Front'('p') and 'Counter' and get relatively tight bounds for their competitive ratios. In both cases, the upper and lower bounds match as the parameter ' d' tends to infinity.
Shaping their lives, accommodating career and motherhood

Although women all function within the same societal constraints, they find their own paths and shape their own lives. This research explores the experiences of eight managerial or professional women who are mothers of young children and whose stories attest to women's abilities to take the many components of their lives and manipulate them in response to the seasons of their lives. In challenging the status quo, the examples of such women provide us with a vision for a future in which women and men could live in a more equitable society, with the constraints of gendered roles slackened. In order to increase our understanding of the choices the women make and how their lives unfold, I have used a life history approach. The research is located in a social constructivist perspective and situated within a feminist framework. Data for the research were gathered through twenty-one in-depth loosely structured interviews with the eight participants. From the transcribed material, I created profiles of each of the women and then engaged in a thematic analysis. I categorized the data under the broad themes of early influences, women's career choices, their marital partnership, motherhood, the dilemmas they face, and accommodating work and family life. In the presentation, the stories of the individual women weave through the themes so that the reader has some insight into the phenomenological experience of each of the women at home and at work. Broader implications are explored in the context of existing theory and counseling implications are discussed. The women were both career and family salient and so they looked creatively for ways in which they could actualize career goals as well as nurturing their children. In seeking to accommodate roles that have traditionally been discrete orientations in our culture, they have challenged stereotypes and created scripts that are based on their own realities.