VictorJuiz/thesis huggingface dataset:
Production and Purification of Silicon by Magnesiothermic Reduction of Silica Fume
Keywords: Solar Grade Silicon
Materials Science

A new approach is discussed for the generation of high purity silicon from silica fume (SF), which is a waste by-product from the manufacture of metallurgical grade silicon. Process steps were developed and optimized including purification of SF, reduction by magnesium, and post-reduction leaching. Reduction was carried out successfully with initial HCl leached SF in a sealed chamber with varying Mg/SF ratios, temperature and time. These variables affected the production of silicon from SF. Suitable reduction conditions were found to be within the temperature range 750-850C and at approximately 2:1 ratio of Mg/SF. Reduction products were treated using a three-stage acid leaching. XRD, QXRD and ICP analyses of the final silicon powder product indicated that silicon with low impurity levels (low boron content) can be produced. Therefore, silicon produced by magnesiothermic reduction can be an attractive source for the production of solar grade silicon.
Testing the Role of an Arf GTPase-activating Protein dASAP in Epithelial Cell Polarity in the Drosophila Embryo
Keywords: Arf GTPase-activating protein
Epithelial cell polarity
Drosophila embryo

Baz/PAR3 is a key regulator of epithelial cell polarity (ECP). To identify proteins functioning with Baz, I completed a baz genetic interaction screen by localizing 15 GFP-tagged candidates. Then I tested the role of a top candidate, dASAP (Drosophila Arf GTPase-activating protein with SH3 domain, Ankyrin repeat and PH domain), in Drosophila ECP. To determine whether dASAP might interact with polarity players, I defined the localization of dASAP throughout embryogenesis with GFP-tagged proteins and an anti-dASAP antibody. To study how loss of dASAP function affects ECP, I generated a deletion allele by imprecise P-element excision. To evaluate how each of the six domains of dASAP contributes to its localization and functions, I generated constructs deleting each domain. I found associations between dASAP, actin and the apical domain. The six domains may act redundantly to localize dASAP, although interactions between domains may affect the degree of membrane association.
The Effect of Rosiglitazone on Bone Quality in a Rat Model of Insulin Resistance and Osteoporosis
Keywords: Rosiglitazone
Bone quality
Zucker Fatty rat
Alendronate
Bone mineral density
Bone formation
Bone resorption

Rosiglitazone (RSG) is an insulin-sensitizing drug used to treat Type 2 Diabetes Mellitus (T2DM). Clinical trials show that women taking RSG experience more limb fractures than patients taking other T2DM drugs. The purpose of this study is to understand how RSG (3mg/kg/day and 10mg/kg/day) and the bisphosphonate alendronate (0.7mg/kg/week) alter bone quality in the male, female and female ovariectomized (OVX) Zucker fatty rat model over a 12 week period. Bone quality was evaluated by mechanical testing of cortical and trabecular bone. Microarchitecture, bone mineral density (BMD), cortical bone porosity, bone formation/resorption and mineralization were also measured. Female OVX RSG10mg/kg rats had significantly lower vertebral BMD and compromised trabecular architecture versus OVX controls. Increased cortical porosity and decreased mechanical properties occurred in these rats. ALN treatment prevented these negative effects in the OVX RSG model. Evidence of reduced bone formation and excess bone resorption was detected in female RSG-treated rats.
Cockayne Syndrome B is Required for Neural Precursor Self-renewal and Neuritegenesis after DNA Damage
Keywords: Neural Stem Cells
DNA damage

Neural precursor cells self-renew and differentiate throughout development and in response to neural injury in the adult brain. The DNA damage response in NPCs has yet to be characterized. Patients with defective nucleotide excision repair (NER) demonstrate neurodegeneration dismyelination, and microcephaly, suggesting a potential link to defective NPC function with accumulating DNA damage. We observed reduced self-renewal in Csbm/m and Xpam/m NPCs in response to UV damage. Serial passaging resulted in exhaustion of Csbm/m NPCs in the absence of exogenous DNA damage. In vitro neuronal differentiation resulted in abnormal neuritigenesis after UV DNA damage in Csbm/m NPCs, suggesting defects in the terminal differentiation process. Taken together, the results indicate that DNA damage can modulate the apoptotic, self-renewal and differentiation fates of NPCs.
Process Pluralism and Systemic Resistance to Child Protection Mediation in Ontario
Keywords: child protection
child welfare
mediation
child protection mediation

This paper focuses on the use of mediation within Ontario’s child protection system. Applying the process pluralism framework advocated by Carrie Menkel-Meadow, the systemic resistance to child protection mediation [CPM] in Ontario is explained. To address this resistance, a particular approach of structuring conflict resolution is evaluated through the lens of process pluralism. It is concluded that increasing the use of CPM at the dispositional stage of a child protection proceeding will improve results for children and their families.
The BCE Blunder: An Argument in Favour of Shareholder Wealth Maximization
Keywords: Corporate Law
Fiduciary Duties
Director Duties
Shareholder
Stakeholder
BCE

The traditional approach to corporate governance in Canada has centered on shareholders. This model of governance is commonly referred to as shareholder primacy. The shareholder primacy model has recently been rejected by the Supreme Court of Canada in Peoples v. Wise and BCE v. 1976 Debentureholders. This paper will be argued that directors should be required to focus exclusively on increasing shareholder value in the change of control context. It is within the change of control context that shareholders most require fiduciary protection. In addition, the shareholder primacy rule provides an enforceable standard for evaluating the actions of directors. As stakeholders have a variety of mechanisms to ensure that their interests are not disregarded, they are not in need of fiduciary protection. In contrast, shareholders face greater risks, which validate a need to be protected by an exclusive fiduciary duty in the change of control context.
High Frequency Ultrasound Backscatter Analysis for the Detection of Early Tumour Response to Radiotherapy and a Novel Anti-vascular Treatment
Keywords: ULTRASOUND
CANCER

There is a need for cancer imaging to provide “real-time” information about the cellular responses of tumours in contrast to standard evaluations of tumour size. Quantitative ultrasound techniques have recently been demonstrated to be a potential method of assessing tumour response at the cellular level through the analysis of radiofrequency backscatter data. In this thesis, prostate cancer xenografts were evaluated in vivo using high-frequency ultrasound analysis techniques to assess tumour response. The anti-cancer treatments consisted of radiotherapy and also a novel anti-vascular therapy utilizing encapsulated microbubble agents in the presence of ultrasound. Quantitative ultrasound results demonstrated a statistically significant change in backscatter parameters in tumours treated with high doses of radiotherapy or a high concentration of microbubbles during treatments. Histopathological assessment demonstrated that tumour cell death due to apoptosis and necrosis correlated with increases in ultrasound parameters.
Assessment of Parental Satisfaction with Dental Treatment Under General Anaesthesia in Paediatric Dentistry
Keywords: Pediatric Dentistry
General anesthesia
parental satisfaction

Purpose: To identify and compare pre-treatment and post-treatment parental expectations and satisfaction concerning their child’s dental care under general anaesthesia. Participant characteristics were also investigated. Methods: Questionnaires were administered to all parents who attended the pre-operative anaesthesia consultation (pre-treatment group) and to all parents who returned for post-operative reassessment (post-treatment group). Participants were asked to rate the importance and frequency of 27 events on a four point Likert Scale. Parents were also asked to complete a participant characteristics information form. A score was calculated for each item in the questionnaires by multiplying the item’s mean “importance rating” and the item’s mean “expectation rating” and the items were ranked by scores. Results: Complete responses were obtained from 100 parents of the pre-treatment group and from 100 parents of the post-treatment group. In each group, the highest ranked elements were those representing information and communication while the physical conditions of care tended to be least valued by the parents. The rank-order of the importance scores showed a moderate to strong positive correlation with the rank-order of the frequency scores. Conclusion: Parents placed value on good communication and provision of information with regard to dental treatment of their children under general anaesthesia.
Conative Factors in the Context of Adolescent Reading Remediation
Keywords: reading disabilities
adolescent
cognition
attributions
motivation
secondary school
reading
effortful control
adolescence

The present study investigated variability in the remedial outcomes of 105 adolescents with reading disabilities who participated in PHAST PACES, a research-based reading intervention with a strong attributional retraining focus. The study focussed on the impact of three conative functions—intrinsic motivation, attributions, and effortful control—and their relationships with reading skill and reading growth. It was hypothesized that, following PHAST PACES, students would demonstrate improvement on reading outcomes, increased intrinsic motivation for reading, a shift from maladaptive to adaptive attributions, and improved effortful control. Students demonstrated significant gains on reading and effortful control measures following PHAST PACES intervention. The intrinsic motivation and attributional profiles of students did not improve. Students who performed best on reading measures at pre- and post-test made attributions of success to ability and avoided attributions of failure to ability, while reporting high perceived competence for reading, and demonstrating good effortful control.
Weakly Trained Parallel Classifier and CoLBP Features for Frontal Face Detection in Surveillance Applications
Keywords: Face detection
Feature extraction
Local Binary Patterns features
Weakly trained classifiers

Face detection in video sequence is becoming popular in surveillance applications. The trade-off between obtaining discriminative features to achieve accurate detection versus computational overhead of extracting these features, which affects the classification speed, is a persistent problem. Two ideas are introduced to increase the features’ discriminative power. These ideas are used to implement two frontal face detectors examined on a 2D low-resolution surveillance sequence. First contribution is the parallel classifier. High discriminative power features are achieved by fusing the decision from two different features trained classifiers where each type of the features targets different image structure. Accurate and fast to train classifier is achieved. Co-occurrence of Local Binary Patterns (CoLBP) features is proposed, the pixels of the image are targeted. CoLBP features find the joint probability of multiple LBP features. These features have computationally efficient feature extraction and provide high discriminative features; hence, accurate detection is achieved.
Exploring the Suitability of a Specifici Glucocorticoid Receptor Antagonist as a Tool in the Study of the Regulation of Rat Lung Alveolarization by Glucocorticoids
Keywords: alveolarization
glucocorticoids
rat lung development
glucocorticoid receptor antagonist

Background: Intracellular glucocorticoid receptors (GRs) mediate the regulation of lung development, including alveolarization, by glucocorticoids (GCs). One potential approach to determining the role of GC-GR signalling in alveolar formation would be by pharmacologic blockade. Hypothesis: CP472555, a novel GR antagonist with negligible anti-PR activity, is a suitable tool for the study of GC-GR regulation of rat alveolarization. Design/Methods: CP472555 doses needed to block GR were estimated in vitro in fetal rat lung primary cultures. Postnatally, a variety of doses were administered intraperitoneally over a range of days. Results: During postnatal days (PN)0-PN10, when GC levels are low, CP472555 induced changes consistent with GR agonist activity. While GC levels increase after PN11, animals exposed to CP472555 from PN11-PN21 exhibit changes consistent with anti-GR antagonist activity. Conclusion: CP472555 causes a degree of GR blockade sufficient to permit further pharmacological investigation of the role of endogenous GC-GR signalling at the end of alveolarization.
A Generic Simulation Model to Improve Procedure Scheduling in Endoscopy Suites
Keywords: health care
simulation
endoscopy
colorectal cancer
throughput
overtime
undertime
hospital

In 2008 Ontario implemented a screening program for colorectal cancer, which drew attention to the increasing demand for colonoscopies in the province. This trend and the forecasted demand of the new screening program created a need to increase capacity in hospital endoscopy suites. This thesis addresses this need by investigating throughput gains from scheduling according to physician specific procedure durations in endoscopy suites. This is accomplished through the development of a scheduler and a generic discrete event simulation. Case study results show that physician specific scheduling can increase throughput in the endoscopy suite while reducing undertime and only slightly increasing overtime. They further indicate the trade off between a 1:2 and 1:1 physician to room ratio, finding that while a 1:1 ratio increases throughput by 33% over a 1:2 ratio, physicians are 1.5 times more productive under a 1:2 ratio.
Characterizing Plasmacytoid Dendritic Cell Activation in the Context of HIV Stimulation
Keywords: HIV
pDC
Interferon
Cytokine

Plasmacytoid dendritic cells (pDCs) are important in innate and adaptive immune responses against viral infections, producing remarkable levels of type I interferon as well as other immunomodulatory cytokines. In vitro, pDCs can control replication of human immunodeficiency virus (HIV). Following natural challenge with simian immunodeficiency virus (SIV), PDCs infiltrate the vaginal mucosa. Despite this, pDCs are unable to prevent systemic dissemination of virus. To understand pDC activation immediately following HIV exposure, cytokine production and maturation of pDCs in response to HIV and a variety of other stimuli was compared. PDCs were found to respond suboptimally to HIV compared to other stimuli, with delayed interferon-alpha production, delayed maturation, and decreased production of inflammatory cytokines. Furthermore, HIV induced inhibitory signaling pathways in pDCs, suggesting subversion of the pDC response by HIV. Finally, different stimuli induced different early and late cytokine profiles, highlighting the complex and stimuli-dependant nature of the pDC response.
Concurrent Self-administration of Alcohol and Nicotine in an Operant Paradigm
Keywords: Alcohol
Nicotine
Self-Administration
Drug abuse
Drinking
Smoking
Rats

Rationale and objectives: Alcohol and nicotine are the most commonly abused drugs and they are often taken together. To help address some of clinical issues regarding nicotine and alcohol co-dependence, a procedure in which rats self-administer nicotine intravenously and alcohol orally during the same operant session has been developed. Methods: Male Wistar rats were trained to self-administer alcohol (12%, w/v; 0.19 ml/delivery) or implanted with jugular catheters and trained to self-administer nicotine (30 μg/kg IV/infusion) by pressing a lever or were trained to self-administer both drugs, some with alcohol first, and others with nicotine first. Results: Animals readily coadministered alcohol and nicotine concurrently. Access to alcohol reduced nicotine selfadministration significantly. Conclusions: These results show that rats will self-administer relevant amounts of intravenous nicotine and oral alcohol concurrently. They also provide further support for the important relationship between nicotine and alcohol.
The Role of Cholinergic Cortical Modulation from the Nucleus Basalis Magnocellularis in Visual and Olfactory Attention using the 5-Choice Serial Reaction Time Task
Keywords: acetylcholine
attention
5-CSRTT

To date, research using rodent models has primarily dealt with the visual aspects of attention, while in the present research, we examined neurochemical modulation of attentional processes using both a visual and an olfactory five choice serial reaction time task (5-CSRTT). The nucleus basalis magnocellularis (NBM) in the basal forebrain is the primary source of cortical cholinergic input, which is thought to have an important modulatory effect on rat attentional processes. Thus, after successful acquisition of the task, the rats were subjected to either a cholinergic immunotoxic or sham lesion surgery of the NBM. Cortical cholinergic deafferentation of the cortical mantle was induced by bilaterally infusing 0.2 µg/µl of the cholinergic immunotoxin, 192 IgG-saporin, into the NBM (saporin-lesion). Reduction of cortical cholinergic modulation led to comparable attentional impairments in the saporin-lesion group, relative to the sham-lesioned group, on both visual and olfactory versions of the 5-CSRTT.
Governing the Restless and Young in Contemporary China: in Search for the Chinese Communist Party's Ruling Logic
Keywords: Chinese politics
Chinese students
Tiananmen
Chinese Communist Party
Authoritarianism
Chinese democracy

This thesis explores one particular facet of contemporary state-society relationship in China, i.e. state-student relationship. By arguing against the popular observation that the Chinese Communist Party (CCP) retreated from Chinese universities as a way of winning students’ support, this thesis claims that the party-state has adopted a “bird cage” strategy in post-Tiananmen university governance. That is to say, the party-state has not only re-established and strengthened its control institutions in universities, but at same time expanded its zone of tolerance and created new outlets for students’ political enthusiasm and participation. A four-city, seven-university field survey was conducted, the result of which supports the view that the CCP’s post-Tiananmen governance strategy has been effective. Respondents agree that party’s governing institutions are resilient and play important roles in students’ life. They also seem to be in agreement with, at least as the survey results indicate, important political ideas promoted by the party-state.
Characterization of Murine Intestinal Mucus Layer Gene Expression during Postnatal Maturation
Keywords: Nutrition

The objective of this work was to characterize the expression pattern of the main intestinal mucin and glycosyltransferases genes in the distal ileum, caecum, proximal and distal colon of 5, 10, 15, 21, 25 and 32 days old mouse pups by real-time PCR. We found that all genes considered, except for Muc13 followed a spatio-temporal expression pattern. As a potential modulator of mucin gene expression, gut microbiota composition was also analyzed in the same animals. We found that neither the total bacterial numbers nor the relative abundance of the main microbial phyla vary after 21 days of age. The characterization of the postnatal intestinal mucus layer gene expression may aid to understand disease-related deviations and help designing nutritional interventions to sustain the intestinal barrier.
The Relationship between Acute and Chronic Aerobic Exercise Response in Pre-hypertensive Individuals
Keywords: Exercise, blood pressure
pre-hypertension, post exercise hypotension

Aerobic exercise is recommended as a lifestyle intervention to reduce blood pressure (BP) in individuals with elevated BP (SBP/DBP >120/80 mmHg). However, the BP response is highly variable after both acute (SBP/DBP: –27 to 9/-8 to 7mmHg) and chronic aerobic exercise (-20 to 9/ -11 to 11.3mmHg). We attempt to identify those who are resistant or responsive to training based on their responses to acute (one-bout) exercise. 17 prehypertensive (120 to 139/80 to 89mmHg) males and females (45-60yrs) underwent acute exercise assessments before and after an 8-week walking/jogging program. The magnitude of change in BP after acute exercise significantly correlated (r=.89, p < .01) with the magnitude of change in resting BP after the training. The antihypertensive mechanisms (total peripheral resistance, baroreflex sensitivity) for acute exercise were not correlated to those for chronic exercise. Central cardiovascular controls may link BP reductions after both acute and chronic exercise.
Effects of Cyclic Hydraulic Pressure on Osteocytes
Keywords: biomechanics
bone
mechanotransduction
osteocyte

Bone changes composition and structure to adapt to its mechanical environment. Osteocytes are putative mechanosensors responsible for orchestrating the bone remodeling process. Recent in vitro studies showed that osteocytes could sense and respond to substrate strain and fluid shear. However the capacity of osteocytes to sense cyclic hydraulic pressure (CHP) associated with physiological mechanical loading is not well understood. In this study, osteocyte-like MLO-Y4 cells were subjected to CHP of 68 kPa at 0.5 Hz, and the effects of CHP on intracellular calcium concentration, cytoskeleton organization, mRNA expression of genes related to bone remodeling, and osteocyte apoptosis were investigated. The results indicate that osteocytes could sense CHP and respond by increased intracellular calcium concentration, altered microtubule organization, an increase in COX-2 mRNA level and RANKL/OPG mRNA ratio, and decreased apoptosis. Therefore cyclic hydraulic pressure in bone a mechanical stimulus to osteocytes and may play a role in regulating bone remodeling.
The Dosimetric Consequences of Intensity Modulated Radiotherapy for Cervix Cancer - the Impact of Organ Motion, Deformation and Tumour Regression
Keywords: cervix cancer
intensity modulated radiotherapy
consensus guidelines
dose accumulation
organ motion

Cervix cancer affects women of all ages and causes significant morbidity and mortality. Locally advanced disease is curable with radiotherapy (RT) in about 50% of patients, although often at the expense of serious side effects. In order to improve the therapeutic ratio of tumour control versus normal tissue toxicity, conformal intensity-modulated radiotherapy (IMRT) is being investigated. However, inter- and intra-fractional motion of cervix cancer can contribute to both geographical miss of the target and overdosing of surrounding normal tissues, particularly in the setting of conformal IMRT with steep dose gradients. Defining the target volume accurately and understanding the dose consequence of these complex intra-pelvic organ dynamics during external beam radiotherapy forms the essential foundations for future treatment optimization and adaptation. This in turn will lead to improvements in tumour control and disease-free survival while minimising treatment toxicity.