VictorJuiz/thesis huggingface dataset:
Facilitatory and Inhibitory Effects of Implicit Spatial Cues on Visuospatial Attention

Previous work suggests that both concrete (e.g., hat, shoes) and abstract (e.g., god, devil) concepts with spatial associations engage attentional mechanisms, affecting subsequent target processing above or below fixation. Interestingly, both facilitatory and inhibitory effects have been reported to result from compatibility between target location and the meaning of the concept. To determine the conditions for obtaining these disparate effects, we varied the task (detection vs. discrimination), SOA, and concept type (abstract vs. concrete) across a series of experiments. Results suggest that the nature of the concepts underlies the different attentional effects. With abstract concepts, facilitation was observed across tasks and SOAs. With concrete concepts, inhibition was observed during the discrimination task and for short SOAs. Thus, the particular perceptual and metaphorical associations of a concept mediate their subsequent effects on visual target processing.

Keywords: visual attention
perceptual symbol systems
Advisor: Pratt, Jay
Timing of DNA Replication and DNA Methylation of Endothelial-Enriched Genes

This study examined the DNA replication timing patterns of endothelial cell (EC)-enriched genes. We especially focused on a unique set of EC-enriched mRNA transcripts that possess differentially methylated regions (DMRs) within proximal promoters. It was previously shown that this DNA methylation plays an important functional role in regulating EC-enriched patterns of gene expression. Since the maintenance of these silencing marks is necessary for the inheritance of cell identity, the cell should ensure the proper transmission of such marks during mitotic cell cycle. Here we show that EC-enriched genes with DMRs replicate early during S phase in both expressing and non-expressing cell types. EC-enriched genes that do not have DMRs followed the expected trend, being early replicating in expressing cell types and late in non-expressing cell types. The relationship between DNA replication and DNA methylation was also investigated. A delay between DNA replication and DNA methylation was observed.

Keywords: endothelial
DNA replication timing
DNA methylation
epigenetics
Advisor: Marsden, Philip A.
The Effect of an Unexpected Auditory Stimulus on the Facial Skin Temperature of the Periorbital Regions as Quantified using Thermal Imaging

Infrared thermal imaging of the periorbital regions of the face shows promise as an input signal modality for an alternative communication system for individuals with conditions that preclude speech or voluntary movement, such as total locked-in syndrome. However, it was unknown if the startle response triggers a change in the skin temperature of these regions; such a change could generate false positives in a thermography-based access system. This study presents an examination of the temperature characteristics of the periorbital regions of 11 able-bodied adult participants before and after an auditory startle stimulus. The results show that the startle response has no substantial effect on the mean temperature of the periorbital regions. This indicates that thermography-based access solutions would be insensitive to startle reactions in their user, an important advantage over other modalities being considered in the context of access solutions for individuals with a severe motor disability.

Keywords: thermal imaging
access technology
startle response
periorbital regions
Advisor: Chau, Tom
Mitigating Natural Disaster: Conceptualization and Implementation of an International Responsibility to Protect

This Note asserts that natural disaster-affected populations have a right to call on the international community to protect basic subsistence interests where their sovereign government is unable or unwilling to do so in the wake of a catastrophic natural disaster. First, this Note situates the right to international humanitarian assistance following a natural disaster as a legitimate right under modern international human rights law, using the normative framework set out by renowned political theorist Charles Beitz. This Note then illustrates how the international humanitarian law doctrine of the Responsibility to Protect provides a clear and coherent way to operationalize the right to post-natural disaster humanitarian assistance, by providing a previously-determined structure for a definitive, yet circumstantially-flexible, determination of first- and second-level responsibilities for eligible international actors to take action in defence of this right.

Keywords: natural disaster
responsibility to protect
Advisor: Brunnee, Jutta
Metabolic and Endocrine Adaptations to Chronically Low Body Mass in Female Wistar Rats

Animal models have yet to characterize alterations in body composition, wheel running activity, food intake, and neuroendocrine parameters, in chronic food restriction. This study investigated changes in these measures in food restricted rats, with and without access to running wheels, over four weeks. The data demonstrated that upon initiation of food restriction IGF-1 reductions paralleled loss of lean tissue while leptin levels were rapidly reduced which paralleled losses in body fat. Further, a lower limit threshold of body fat was identified, below which the correlation between leptin and fat mass was disrupted. Lastly, a decrease and plateau in body mass was mirrored by an increase and plateau in voluntary wheel activity in the food restricted population. The data suggest that there is a tight biological link between hyperactivity and body mass and that adequate nutritional support might attenuate the drive for obligate exercise even before weight is fully restored.

Keywords: Food Restriction
Endocrinology
Anorexia Nervosa
Metabolism
Advisor: Amara, Catherine
Effect of Intravenous Saline Infusion and Venous Compression Stockings on Upper Airway Size and Obstruction

Obstructive sleep apnea (OSA) severity is strongly associated with the degree of overnight peripharyngeal fluid accumulation. We hypothesized that intravenous fluid loading would cause upper airway (UA) narrowing or increase the frequency of apneas and hypopneas per hour of sleep (apnea-hypopnea index; AHI). We employed a controlled, randomized double-crossover experiment in 9 healthy men aged 23-46 years. In the control, subjects were administered approximately 80 ml of normal saline intravenously during sleep. In the intervention, subjects were administered approximately 1850 ml of saline during sleep while wearing compression stockings to localize fluid rostrally. The intervention induced nuchal fluid accumulation, resulting in an increase in neck circumference (+0.1 cm during control, +0.6 cm during intervention, P< 0.01 ) and a decrease in UA cross-sectional area (-0.08 cm2 during control, -0.43 cm2 during intervention, P = 0.023). Although the intervention did not increase the AHI (control AHI = 19.5, intervention AHI = 30.3, P = 0.249), the AHI during the intervention correlated with age (r = 0.8, P < 0.01). Thus, intravenous saline loading during sleep can narrow the UA, which in older men may induce or worsen OSA. Further studies are needed to test this hypothesis.

Keywords: Obstructive Sleep Apnea
Nuchal Fluid Accumulation
Fluid Loading
Compression Stockings
Advisor: Bradley, T. Douglas
Fractal Dynamics of Circle Drawing in Children with ASD

Sensory motor deﬁcits, although not part of the diagnostic criteria, are frequently reported in autism spectrum disorder (ASD). The ob jective of this project is to study the temporal and spatial dynamics of an approximately periodic motor activity (circle drawing) in children with ASD. The natural rhythm of periodic motor activities such as circle drawing are known to exhibit statistical persistence in typically developing individuals. A sample of 15 children aged 4 to 8 years, with a primary diagnosis of ASD were asked to draw circles using a computerized tablet and pen, which record spatio-temporal data. Results were compared with those of 19 typically developing children. While no diﬀerences were seen in statistical persistence, diﬀerences were observed in timing of discontinuous circle drawing and in kinetic process variable such as grip and axial forces. Understanding the speciﬁc nature of graphomotor deﬁcits is the ﬁrst step towards developing targeted treatment for these impairments.

Keywords: Autism spectrum disorder
Fine motor activity
Statistical persistence
Motor timing
Advisor: Chau, Tom
Anagnostou, Evdokia
Genetic and Phenomic Determinants of Basal Mechano-sensitivity and Spread of Neuropathic Pain Following Transection of the Infraorbital Nerve in Mice

Craniofacial nerve injury occasionally causes spread of mechanical hypersensitivity in humans. We modeled this abnormality by transecting the infraorbital nerve (IONX) in male and female mice of the 23 AXB-BXA recombinant inbred lines and their progenitor strains, comparing their responsivity to 7 applications of a 0.2 gram Von Frey filament to the ears, paws and tail. When normalizing their mechano-responsivity on postoperative days 14 and 21 by the preoperative values, subtracting data of sham-operated from IONX mice, highly contrasting line/strain-specific differences were demonstrated. Similar line/strain-specific variability in the spread of mechano-allodynia to the paws post-IONX was demonstrated in our novel 3 minute place-avoidance paradigm, assessing parameters of mobility on a smooth surface versus a pro-allodynic granular surface. These genetically-controlled, widespread changes in mechano-sensitivity caused by IONX were minimally sexually dimorphic and mapped to intervals on chromosomes 5, 9, and 13. Further analysis is needed to identify the causative genes.

Keywords: Neuropathic Pain
Pain Spread
Pain Genetics
Advisor: Seltzer, Ze'ev
The Role of the Innated Immune System in Bisphonate-induced Osteonecrosis of the Jaw

Bisphosphonate-induced osteonecrosis of the jaw (BPONJ) has been identified as a severe complication of dental treatment in 1-10% of patients previously treated with intravenous bisphosphonates. The mechanism by which bisphosphonates induce BPONJ is uncertain. It has been noted that necrotic bone from BPONJ sites display signs of bacterial infection that suggests that an immune defect may play a role in the pathophysiology of BPONJ. The purpose of this thesis examined the effect of a potent bisphosphonate, zoledronate, on the innate immune system, specifically, neutrophil function, differentiation and survival with in vitro and in vivo murine models. Zoledronate exposure leads to decreased neutrophil migration, neutrophil NADPH oxidase activity, circulating neutrophil counts, as well as neutrophil survival, however does not appear to affect neutrophil differentiation. We present evidence that bisphosphonates have the potential to depress the immune system in mice and a subset of patients, possibly contributing to the pathogenesis of BPONJ.

Keywords: Neutrophil
Bisphosphonate
Advisor: Glogauer, Michael
An Ex Post Evaluation of the Ridership Impacts of the VIVA Bus Transit System

The Regional Municipality of York introduced a new bus service known as VIVA in 2005. Although it has been deemed a success by many, it remains to be seen to what degree transit use was affected by its introduction. This study shows that transit ridership in York jumped substantially immediately after the implementation of VIVA. Furthermore, it is determined that the majority of new transit users in York are making home-based work or post-secondary school trips. To evaluate this, home-based work and post-secondary school generalized extreme value discrete choice models are estimated. Improvements in transit service are found to have a greater impact on transit mode share than increases in congestion for both work and post-secondary school trips. It is also, however, concluded that transit improvements played a relatively small role in the considerable shift to transit amongst post-secondary students.

Keywords: Transportation Planning
Evaluation
Public Transit
Bus Rapid Transit
Advisor: Shalaby, Amer Saïd
Miller, Eric
Diatom Records of Holocene Climatic and Hydrological Changes in the Western Hudson Bay Region, Canada

Rapidly changing climates in northern Canada make the western Hudson Bay region an area of high importance for paleoenvironmental studies. Long-term changes in assemblages of diatoms (microscopic algae) were analyzed from lake sediment cores from Baker Lake, Nunavut, and Lake AT01, northern Ontario, to track responses to past environmental changes. Diatom assemblages dating to 6700 years ago in AT01 were initially characterized by cold- tolerant Fragilarioid assemblages, but shifted to an assemblage dominated by large benthic species and Cymbella diluviana consistent with the timing of the Holocene Thermal Maximum after 6300 years BP. A possible drainage event in Lake AT01 may have added significant hydrologic control on the diatom assemblages. The post-industrial period is marked by the largest compositional shifts in both records. Assemblages during the 20th century are indicative of reduced ice cover and enhanced thermal stratification linked to a climate regime shift noted in Hudson Bay since the mid-1990’s.

Keywords: Diatoms
Hudson Bay Lowlands
paleoclimatology
paleolimnology
climate
hydrology
Advisor: Finkelstein, Sarah A.
Between Art and Artifact: the Photography of Abel Boulineau

This thesis explores the function, classification, and re-contextualization of historical photographs as they are understood and digested by art museums. The Abel Boulineau French Regional Life collection at the Art Gallery of Ontario (AGO), which I researched, re-organized, and re-attributed during the summer of 2010, provides a case study for this topic. I investigate the contingencies of meaning surrounding late-nineteenth and early-twentieth century photography, and the inadequacy of art historical models for interpreting works not originally created as aesthetic objects. I explore how museums must understand and grapple with its early photography, and the implications of re-contextualizing such collections within its institutional discourses. The work of producing an attribution places necessary emphasis on photographs as historical entities, and recovers information about their original creation and circulation. Surveying the French Regional Life collection reveals both the pragmatic and theoretical issues involved in making an analysis of early photography.

Keywords: Photographic Collections
Museums
Advisor: Brower, Matthew
Investigation of Active Vibration Suppression of a Flexible Satellite using Magnetic Attitude Control

The problem of attitude control of a flexible satellite using magnetic attitude control is investigated. The work is motivated by JC2Sat - a joint CSA and JAXA mission whose main purpose is a proof of concept of two satellites performing differential drag formation flying. The impact of additional flexible drag panels (of various sizes) on the attitude control is assessed. JC2Sat's attitude control system consists of three perpendicular magnetorquers and one reaction/bias-momentum wheel. Four Linear Quadratic Regulator controllers are compared, ranging in complexity from being time-invariant and assuming a rigid satellite, to being periodic and actively suppressing panel vibrations. These include the first controllers which use magnetic attitude control to actively suppress vibrations, and where the periodic vibration suppression controller is able to guarantee asymptotic stability of the linearized system. It was found that for larger panels, the controllers which actively suppressed the vibrations outperformed those that did not.

Keywords: magnetic attitude control
multibody dynamics
Advisor: Liu, Hugh H. T.
Ruiter, Anton De
Effects of an Early Season Heat Wave on Ecophysiological Parameters Related to Productivity in Sugar Maple (Acer saccharum Marsh.)

Anticipated increases in the frequency, duration or intensity of high temperature events ('heat waves') have the potential to significantly impact forest form and functioning, but these events remain virtually unstudied in forest ecosystems. This thesis presents the results of an event-driven research effort into the impacts of three days of record-setting high temperatures in late May 2010 on key ecophysiological parameters in Sugar Maple (Acer saccharum. Marsh). High temperatures reduced photosynthetic capacity by ~66% versus previous years and total end-of-season leaf litter production by ~33% versus prior measurements. It is predicted that these reductions substantially reduced productivity for Sugar Maple in 2010. These results constitute the first description of the impacts of a short-duration heat wave on productivity-related parameters in a temperate forest tree. The predicted increase in high temperature events could make such impacts a significant, though so far overlooked, pathway of climate change impacts on temperate forests.

Keywords: forestry
plant physiology
climate change
heat wave
ontogeny
canopy gradients
productivity
carbon cycling
age/size changes
Sugar Maple
Acer saccharum
temperature forests
leaf neoformation
leaf shedding
ontogenetic variation
Advisor: Thomas, Sean C.
Homelessness and Oral Health in Toronto

Objectives: This study aimed to assess the oral health status of the Toronto adult homeless population; to learn how they perceive their own oral health; and how they interact with the dental care system. Methods: This cross-sectional descriptive study collected data from 191 homeless adults who were randomly selected using a stratified cluster sample at 18 shelters. A questionnaire and clinical oral examination were conducted with participants. Results: The mean Decayed/Missing/Filled Teeth (DMFT) score of the subjects was 14.4 (SD=8.1). Only 32% of them had visited a dentist during the last year; 75% believed that they had untreated dental conditions; and 40% had their last dental visit for emergency care. The clinical oral examination observed that 88% needed fillings, 70% periodontal, 60% prosthodontic and 40% emergency treatment. Conclusion: Homeless adults in Toronto have poor oral health, significant oral health treatment needs and a lack of access to dental care.

Keywords: oral health
homeless
Advisor: Quiñonez, Carlos
Sovereignty Denied & Sovereignty Yielded:Through the Looking Glass on 21st Century Piracy in the Seychelles

Using the case study of 21st century Piracy as it affects the small islands archipelagic state of the Seychelles, this paper sets the stage for a broader discussion on the sovereignty of small island states in international law. Sovereignty can be viewed through different lenses; sovereignty denied considers the many challenges faced by small island states and their claim to the traditional concept of sovereignty, as promoted during the decolonisation era and projected by the right of self determination. On the other hand sovereignty can also be yielded by small island states, where the jurisdiction of the state becomes a resource. This is demonstrated through the degree of international assistance afforded to the Seychelles in dealing with pirates and more generally, through the development of offshore companies in small island states. Consequently, this paper suggests that international law is both the problem and solution to the sovereignty of small island states.

Keywords: International Law
Seychelles
Piracy
Pirate
Somali Pirate
Small Island State
Decolonisation
Colonial
Indian Ocean
Non Aligned Movement
Offshore
Jurisdiction
Equality
Inequality
Sovereignty
Self Determination
Advisor: Karen, Knop
Calpain and Calpastatin in a Mouse Model of Acute Myeloid Leukemia

I have studied the calpain system in acute myeloid leukemia using the 32D and 32Dkit cell lines. Specifically, I characterized the calpain system in the cell lines, and performed calpastatin overexpression and knockdown studies. I found that calpain activity is elevated in the 32D and 32Dkit cells, and calpain inhibition causes apoptosis. Both μ- and m-calpain contribute to the calpain activity in these cell lines. The 32Dkit cells have higher calpain activity than the 32D cells, which I have shown is partially attributed to basal ckit activation. Calpastatin was present in both cell lines, but exists mainly in a degraded form. Calpastatin overexpression lowered calpain activity and provided a growth disadvantage to the 32Dkit cells, but had no effect on 32D cells. Calpastatin knockdown caused a significant increase in calpain activity in the 32D cells, which changed the cell cycle distribution but had no other major effects.

Keywords: calpain
acute myeloid leukemia
Advisor: Berger, Stuart
Single Implant Supported Crowns in the Aesthetic Zone. Patient Evaluation of Aesthetic Appearance Compared to Laypersons and Dentists.

OBJECTIVE: To appraise the patients’ aesthetic awareness following an implant restoration in the anterior maxilla as compared to dentists and laypeople. MATERIALS AND METHODS: Patients (n=139) restored with an implant-retained crown in the anterior maxilla were invited to rate their satisfaction. Projected magnified images of the crowns were appraised by dentists (n=8) and laypeople (n=6) in room settings. The laypeople judged also printed 10x15cm photographs. Differences in the levels of satisfaction between the actual patient, dentists, and laypeople were compared. PES/WES and Jemt papilla scores were also assigned. RESULTS: Laypeople were less critical than the dentists when judging from printed photographs and vice versa when same images were magnified and projected onto screen. CONCLUSION: Patient satisfaction and awareness of aesthetic appearance following an implant treatment in the aesthetic zone appears to differ from dentists’ and laypeople’s observations. Laypeople’s evaluation is influenced by the method used for appraising the aesthetic outcomes.

Keywords: dental impant
aesthetics
Advisor: Jokstad, Asbjorn
The Automated Detection of Changes in Cerebral Perfusion Accompanying a Verbal Fluency Task: A Novel Application of Transcranial Doppler

Evidence suggests that cerebral blood flow patterns accompanying a mental activity are retained in many locked-in patients. Thus, real-time monitoring with functional transcranial Doppler (TCD) together with a specific mental task could control a brain-computer interface (BCI), thereby providing self-initiated interaction. The objective of this study was to create an automatic detection algorithm to differentiate hemodynamic responses coincident with one's performance of verbal fluency (VF) versus counting tasks. We recruited 10 healthy adults who each silently performed up to 30 VF tasks and counted between each. Both middle cerebral arteries were simultaneously imaged using TCD. Linear Discriminant Analyses (LDA) successfully differentiated between VF and both prior and post counting tasks. For every participant, LDA achieved the 70% classification accuracy sufficient for BCIs. Results demonstrate automatic detection of a VF task by TCD and warrant further investigation of TCD as a BCI.

Keywords: Transcranial Doppler
access technology
Brain-computer Interface
laterality
verbal fluency
cerebral blood flow
Advisor: Chau, Tom