VictorJuiz/thesis huggingface dataset:
Development of a Microfluidic Device for Selective Electrical Lysis of Plasma Membranes of Single Cells

A primary objective of modern biology is to understand the molecular mechanisms which underlie cellular functions and a crucial part of this task is the ability to manipulate and analyze individual cells. As a result of interdisciplinary research, microfluidics may become the forefront of analytical methods used by biologists. This technology can be used to gain unprecedented opportunities for cell handling, lysis and investigation on a single cell basis. This thesis presents the development of a microfluidic device capable of selecting individual cells and performing selective electrical lysis of the plasma membrane, while verifying intactness of the nuclear membrane. The device is fabricated by an improved photolithography method and integrates molten solder as electrodes for lysis by a DC electric field. Quantification of lysis is accomplished by video and image analysis, and measurement of the rate of ion diffusion from the cell.

Keywords: Microfluidics
Single Cell
Electrical Lysis
Lab-on-a-Chip
Electrophoresis
Selective Lysis
Photolithography
Advisor: Lilge, Lothar
QoE-based Application Mapping for Resource Management

Mapping between many different applications and many different underlying technologies is very complicated. Moreover, since users need service continuity and want to get the service in a satisfactory level, firstly, their perception of the service should be measured and secondly, the changes in the underlying technologies should be transparent to users. As a result, there should be ”virtualization layer” between application layer and underlying access technologies whose job is to abstract user perception of the application in terms of network parameters and transfer these requirements to underlying layers. In this thesis, we propose a generic mathematical expression to abstract user perception of application in a unified way for different applications. Since today applications are composite applications, having a generalized expression that has the same form for various applications can ease resource management calculations. We use application service map which is based on quality of experience for resource management.

Keywords: Mean Opinion Score
General Expression
QoS Class Mapping
Quality Assessment
Multimedia
Application Virtualization
Advisor: Alberto, Leon-Garcia
Decarburization and Melting Behavior of Direct-reduced Iron Pellets in Steelmaking Slag

An experimental study was undertaken to quantify the rate of DRI decarburization in a steelmaking slag using the constant–volume pressure increase technique. Experiments were conducted by dropping DRI pellets into molten slag at temperatures from 1500°C to 1600°C. Further experiments were carried out in which the DRI pellets were preheated while the slag temperature remained constant. The effect of initial carbon content and preheating temperature of the DRI on the reaction rate was investigated. The decarburization of DRI appears to comprise of two stages; reaction with the FeO of DRI, followed by further decarburization through the iron oxide of slag. Carbon has a significant effect on the kinetics of both stages while the preheating temperature mainly influences the rate of the reaction between FeO and carbon inside the pellet.

Keywords: Steelmaking
DRI
Advisor: Barati, Mansoor
Development of Test Methods for Assessment of Concrete Durability for Use in Performance-based Specifications

Many Ministry of Transportation of Ontario (MTO) projects consist of construction and maintenance of reinforced concrete structures. Where appropriate test methods exist, MTO has been moving towards use of performance-based specifications for durability control of concrete. MTO currently uses ASTM C1202 (RCPT) coulomb values to assess concrete durability. This test requires taking cores, so replacing this test with a faster non-destructive technique is important. The main focus of this program was to study the Wenner probe surface resistivity as a non-destructive test device and evaluate the potential for replacement of RCPT with the Wenner resistivity. This research program consists of the determination of RCPT values, water sorptivity coefficients and electrical resistivities (bulk and surface) of nine concrete mixtures. In addition, the development of the Wenner probe instrument was studied. As well, correlations between resistivity and ASTM C1202 and C1585 are provided followed by technical recommendations for improving the Wenner test.

Keywords: Concrete durability
Permeability
Surface electrical resistivity
Water sorptivity
Wenner probe
RCPT coulombs passed
DC-cyclic bulk resistivity
Advisor: Hooton, Robert Douglas
The Role of Estrogens in Cognition: Does Prophylactic Oophorectomy Affect Verbal, Spatial and Working Memory?

Studies of non-human animals have shown that estrogens have a significant effect on the structure and neurochemistry of the brain and on cognitive behaviours. This study examines women with BRCA1/2 mutations who have undergone bilateral salpingo-oophorectomy (BSO), resulting in surgical menopause. In order to understand how the absence of endogenous estrogens affects cognition, women with BSO are compared to women with BRCA1/2 mutations but without BSO, as well as age-matched controls on tests of verbal, spatial and working memory. Women with BSO show decreased verbal memory and attention (logical memory) relative to controls but better performance on a measure of temporal lobe function (fluency clustering). Further, concentration of estrogen metabolites (E1G) negatively correlated with performance on a spatial memory task (object placement task) and with fluency clustering. These results indicate that endogenous estrogens are important for verbal memory and attention, but may contribute negatively to spatial memory and fluency clustering.

Keywords: Estrogens
Cognition
Advisor: Einstein, Gillian
Truncated Cell Surface Markers Fused with Mutant Human Tmpk: Versatile Cell Fate Control Safety Cassettes for Lentiviral Vector Mediated Correction of Fabry Disease

Lentivirus-mediated gene therapy has curative potential for a variety of disorders, however, insertional oncogenesis still remains a concern. One approach to increase safety of such treatment modalities is to include a ‘cell fate control safety cassette’ in lentiviral vectors (LVs), enabling pharmacological control over the survival of gene-modified cells (GMCs). Two novel LVs with engineered expression of truncated cell surface molecules (CD19 or LNGFR) fused to a ‘cell fate control’ gene (TmpkF105YR200A) were constructed. Results demonstrated these safety cassettes could be used to control the survival of GMCs in a murine xenogeneic leukemia models. For treatment of Fabry disease, a bicistronic LV containing the fusion safety element and therapeutic α-galactosidase A was constructed. Transduction with this vector restored enzyme activity in Fabry patient’s fibroblasts. These collective results demonstrate that this approach is sufficient to eradicate GMCs, and when combined with a corrective cDNA can provide therapeutic benefit for Fabry disease.

Keywords: gene therapy
fabry disease
Advisor: Medin, Jeffrey A.
Modelling the Impact of Weather Conditions on Active Transportation Travel Behaviour

Three weather sensitive multinomial logit models are estimated using the 2001 Transportation Tomorrow Survey in order explore the relationship between weather and home-based work trips within the City of Toronto, focusing on active modes of transportation. The data is restricted to non-captive commuters who have the option of alternating between all five basic modes of auto driver, auto passenger, transit, bike and walk with change in weather. Daily trip rates in various weather conditions are assessed. The combined effect of the daily trip rate and mode choice analysis is applied to several climate change scenarios. A 6oC increase in temperature can increase cycling trips by 17%, and reduce auto-passenger trips by 7%. A 20% increase or decrease in precipitation, however, is found to have much smaller impacts on all modes. Overall, the results confirm that impact of weather on active modes of transportation is significant enough to deserve attention at the research, data collection and planning levels.

Keywords: mode choice modelling
active transportation
impact of weather conditions
Advisor: Roorda, Matthew J.
Kennedy, Christopher A.
Differential Protein Interactions of NMDA Receptor NR2 Subunits

NMDA-type glutamate receptors (NMDAR) regulate neurotransmission and excitotoxicity. NMDAR signaling is believed to be dependent on NR2 subunit (A-D) composition and interactions with intracellular proteins. To determine the role of individual NR2 subunits in NMDAR signaling, I examined the biochemical interactions and colocalization of NR2A and NR2B NMDAR subunits with PSD-95 and CaMKII. Immunofluorescent colocalization revealed that by perturbing PSD-95 PDZ interactions using a targeted peptide (TAT-NR2B9c) increased association of PSD-95 with NR2A and CaMKII with NR2B; furthermore, decreases in association of CaMKII with NR2A and PSD-95 with NR2B were observed. The effects of TAT-NR2B9c were dependent upon NMDAR stimulation with 10μM NMDA and were not observed in untreated cells or at toxic doses of NMDA (40 μM). Thus, disrupting PSD-95 PDZ interactions produced activity-dependent differences in the co-localization of NR2A and NR2B with key signaling proteins, providing evidence that individual NR2 subunits may confer differential signaling to NMDARs.

Advisor: Aarts, Michelle
Hypocretin/Orexin Neurons Endogenously Regulate Somatic Motoneuron Excitability

The role of hypocretin neurons in modulating somatic motoneuron excitability and hence muscle tone is poorly understood. We investigated whether hypocretin neurons influence the hypoglossal and trigeminal motor pools that innervate the genioglossus and masseter muscles respectively, both of which function to maintain upper airway patency. We hypothesized hypocretin neurons facilitate motor outflow at the motor pools. We pharmacologically manipulated hypocretin neuron activity in anaesthetized mice to determine their role in somatic motoneuron excitability. We also antagonized hypocretin receptors in the hypoglossal motor pool to determine the pathway through which hypocretin neurons influence motoneuron excitability. We demonstrated that hypocretin neurons potently excite somatic motoneurons and hence facilitate genioglossus and masseter muscle tone. Furthermore, we demonstrated that an endogenous hypocretinergic drive on somatic motoneurons facilitated muscle tone under anaesthesia. These studies demonstrate that hypocretin is an excitatory neuromodulator of muscle tone and contributes to the excitatory regulation of somatic motoneurons.

Keywords: Hypocretin
Advisor: Peever, John H.
Music Processing in Deaf Adults with Cochlear Implants

Cochlear implants (CIs) provide coarse representations of pitch, which are adequate for speech but not for music. Despite increasing interest in music processing by CI users, the available information is fragmentary. The present experiment attempted to fill this void by conducting a comprehensive assessment of music processing in adult CI users. CI users (n =6) and normally hearing (NH) controls (n = 12) were tested on several tasks involving melody and rhythm perception, recognition of familiar music, and emotion of recognition in speech and music. CI performance was substantially poorer than NH performance and at chance levels on pitch processing tasks. Performance was highly variable, however, with one individual achieving NH performance levels on some tasks, probably because of low-frequency residual hearing in his unimplanted ear. Future research with a larger sample of CI users can shed light on factors associated with good and poor music processing in this population.

Keywords: cochlear implants
music
hearing
pitch
rhythm
timbre
Advisor: Trehub, Sandra E.
Schellenberg, E. Glenn
Production and Purification of Silicon by Magnesiothermic Reduction of Silica Fume

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.

Keywords: Solar Grade Silicon
Materials Science
Advisor: Barati, Mansoor
McLean, Alexander
Testing the Role of an Arf GTPase-activating Protein dASAP in Epithelial Cell Polarity in the 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.

Keywords: Arf GTPase-activating protein
Epithelial cell polarity
Drosophila embryo
Advisor: Harris, Tony
The Effect of Rosiglitazone on Bone Quality in a Rat Model of Insulin Resistance and Osteoporosis

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.

Keywords: Rosiglitazone
Bone quality
Zucker Fatty rat
Alendronate
Bone mineral density
Bone formation
Bone resorption
Advisor: Grynpas, Marc D.
Cockayne Syndrome B is Required for Neural Precursor Self-renewal and Neuritegenesis after 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.

Keywords: Neural Stem Cells
DNA damage
Advisor: Laposa, Rebecca
Process Pluralism and Systemic Resistance to Child Protection Mediation in Ontario

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.

Keywords: child protection
child welfare
mediation
child protection mediation
Advisor: Rogerson, Carol
The BCE Blunder: An Argument in Favour of Shareholder Wealth Maximization

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.

Keywords: Corporate Law
Fiduciary Duties
Director Duties
Shareholder
Stakeholder
BCE
Advisor: MacIntosh, Jeffrey G.
High Frequency Ultrasound Backscatter Analysis for the Detection of Early Tumour Response to Radiotherapy and a Novel Anti-vascular Treatment

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.

Keywords: ULTRASOUND
CANCER
Advisor: Czarnota, Gregory J.
Assessment of Parental Satisfaction with Dental Treatment Under General Anaesthesia in Paediatric Dentistry

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.

Keywords: Pediatric Dentistry
General anesthesia
parental satisfaction
Advisor: Saltzman, Brett
Conative Factors in the Context of Adolescent Reading Remediation

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.

Keywords: reading disabilities
adolescent
cognition
attributions
motivation
secondary school
reading
effortful control
adolescence
Advisor: Lovett, Maureen W.
Weakly Trained Parallel Classifier and CoLBP Features for Frontal Face Detection in Surveillance Applications

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.

Keywords: Face detection
Feature extraction
Local Binary Patterns features
Weakly trained classifiers
Advisor: Plataniotis, Konstantinos N.