VictorJuiz/thesis huggingface dataset:
Controlled Synthesis of Polytellurophenes

Polytellurophenes are an emerging class of conjugated polymers. This thesis presents studies on the controlled synthesis of polytellurophenes, charge carrier mobilities in polytellurophenes transistors as well as sulfur and selenium analogues, and the role of halogens in Kumada catalyst transfer polycondensation (KCTP). Chapter 2 describes the first controlled synthesis of well-defined, high molecular weight poly(3-alkyltellurophene)s using KCTP through a systematic investigation of polymerization conditions, computation, and molecular design. This enables the preparation of a series of regioregular, high molecular weight, low dispersity poly(3-alkylchalcogenophene)s (S, Se, Te) (Chapter 3). Due to the improved intrachain carrier transport conferred by heavier heteroatoms, polytellurophene exhibits the highest hole mobility in field-effect transistors even though polytellurophene appears to be the least crystalline compared to its lighter analogues. In Chapter 4, the nickel-catalyzed polymerization mechanisms of a series of thiophene monomers bearing different halogen functionalities (Cl, Br, I) were investigated. The significant role that halogens and magnesium salts play in this polymerization was discovered. These findings were used to guide the design of a new monomer, 2-bromo-3-(2-ethylhexyl)-5-iodotellurophene, which enables the first controlled polymerization of a tellurophene monomer containing a sterically encumbered 2-ethylhexyl side chain. Chapter 5 presents preliminary results on the thiophene-tellurophene block copolymerization as well as the isolation of living polymer chains in KCTP.

Keywords: Conjugated Polymers
Controlled Polymerization
Kumada Catalyst Transfer Polycondensation
Polytellurophenes
Advisor: Seferos, Dwight S
After Reading Recovery: Collective Case Studies of the Writing Development of Former Reading Recovery Students in Grade Two

This qualitative collective case study explored the written language development of four grade two students who made accelerated progress in Reading Recovery. The focus was children writing in classrooms — the ways in which their literacy behaviours continued to develop, and the ways in which the classroom context influenced development. The study was positioned within a sociocultural framework, acknowledging the importance of social interaction as a context for learning and development (Vygotsky, 1978). Literacy behaviours observed during the act of writing were interpreted from a literacy processing view of progress (Clay, 2001). What emerged from the data were a number of observable behaviours which showed how each student went about communicating in written language. Analyses of the type and frequency of each behaviour revealed a menu of actions that the students drew on in individual ways. These actions were interpreted as composing, constructing and monitoring actions, which were further described as internal resources within the child’s control and external resources coming from the social context of the classroom. Students also had unique profiles for applying directional and spatial rules, letter, word and sentence knowledge, and punctuation, with movement toward conventional forms of meaningful communication in written language. Students also drew on external resources within the classroom environment — classroom materials, classmates, classroom volunteers or assistants, and their teacher. Teachers influenced writing development through personalized learning experiences. Interactions facilitated a next step, focused attention, and provided the student with feedback. Knowledge of case study students as developing writers and the specific expectations of the curriculum for grade two students influenced the content of teacher and student interactions. Although not meeting all of the specific expectations for writing, the case study students were making progress in the classroom, and interviews revealed their sense of themselves as writers intertwined with their identity as learners.

Keywords: Classroom
Development
Literacy
Literacy Processing
Reading Recovery
Writing
Advisor: Stagg Peterson, Shelley
Investigating Fine Structures of the Earth’s Interior Based on Spectral-element Seismic-wave Simulations

One of the ultimate goals in the studies of seismic waves is to utilize the entire records of seismograms and exploit these waveforms to map the heterogeneity and anisotropy in the Earth's interior. An important technique towards this goal is full waveform inversion (FWI), which often combines accurate numerical solvers of wave equations with gradient-based iterative model updates. Meanwhile, the model resolved by seismic tomography using the relatively low-frequency component of seismograms is only an equivalent smooth one (i.e., homogenized model) of the complex geological structures (i.e., the Earth). In this thesis, we first present the application of homogenization theory to transversely isotropic models and demonstrate the computational efficiency gained from using effective media in forward seismic wave simulations. An efficient wave-equation solver is vital to FWI as forward modeling is repeatedly used to compute accurate synthetics for the updated model to match the observations. Full numerical solvers based on spectral-element method (SEM) are desirable in this task of resolving fine-scale structures, but the associated computational cost can be prohibitive when the simulation frequency becomes high. Hybrid method can be used to reduce the computational cost by restricting the 2D/3D numerical solver to the target region where complex structures reside. We present the framework of an SEM-based two-way hybrid method where the target region can be anywhere inside the Earth. This two-way hybrid method can help map detailed heterogeneities in the lowermost mantle with the unprecedented resolution of FWI. As part of the work in this thesis to investigate fine-scale structures, we have also systematically measured the apparent splitting of vertically and horizontally polarized diffracted S waves along the core-mantle boundary (CMB) based on cross-correlation traveltimes, choosing Aleutian and west Africa as the study regions. Waveform simulations based upon SEM demonstrate that the SHdiff/SVdiff apparent splitting times from isotropic effects are comparable in magnitude to those from actual observations. These apparent splittings should be attributed to the different SHdiff and SVdiff sensitivities even in isotropic Earth models. Therefore, 1D and 3D isotropic effects, rather than intrinsic anisotropy, need to be first incorporated in the interpretation of SHdiff/SVdiff apparent splitting.

Keywords: Computational Seismology
Deep Earth structures
Seismic wave modeling
Spectral-element method
Advisor: Liu, Qinya
A Critical Ethnography of Disability in Committed Relationships

Finding loving, committed relationships can be a difficult journey for many people, but the quest poses additional challenges for disabled people (Rintala et al., 1997; Wade, 2002). Disability rights has advanced in many areas—for example, physical accessibility of the built environment—but harmful social stigma regarding attractiveness, sexual function, and abilities related to fulfilling a partnership role continues to enact barriers for disabled people when seeking and enjoying romantic relationships (Bahner, 2012; Esmail, Darry, Walter, Knupp, 2010; Gill, 1996; Rintala et al., 1997; Shakespeare, Gillespie-Sells, Davies, 1996). Although discrimination in the area of dating, partnership and relationships can often be the most distressing and painful aspects of social exclusion for disabled people, there is a lack of comprehensive research and advocacy surrounding these issues (Finger, 1992; Shakespeare, 2000). Using a critical ethnographic approach (Madison, 2011; Thomas, 1993) in this research, I explore whether the experiences of disabled people and their partners reflect, reject, and/or reimagine dominant cultural assumptions about the experience of disability within relationships. Eight couples, where one or both people identify as having a disability, were interviewed about their experiences as a couple and the role that disability had in their relationships. Interview transcripts were analyzed using Charmaz's (2014) constructivist grounded theory, and the analysis is presented within two broad categories: disability-related experiences in the foreground and background of committed relationships; and the productive and positive value of disability-related experiences in committed relationships. I conclude that disability is experienced in a wide variety of ways both between and among individuals and couples; disability is not necessarily the most important or the most pressing consideration in the day-to-day lives of couples, and disability-related experiences have the potential to be positive and productive within committed relationships.

Keywords: disability
intimacy
relationships
sexuality
Advisor: Yoshida, Karen K
Increasing Chemosensitivity in Colorectal Cancer

Despite being one of the most genetically understood cancers, colorectal cancer is still one of the leading causes of death due to cancer. Here we focus on two mechanisms of chemoresistance in colorectal cancer; the increased antioxidant response of colorectal cancer-initiating cells (CC-ICs) and the aggregation of p53. Most CRCs contain a subset of self-renewing CC-ICs responsible for tumor initiation and maintenance that are chemoresistant compared to the bulk tumor cell population. The overexpression of Nrf2, the master regulator of the antioxidant response system, allows for the detoxification of chemotherapy and increased CC-IC survival. We show that CRC cells upregulate their antioxidant activity in response to chemotherapy and that CC-IC self-renewal is dependent on Nrf2 function where genetic knockdown of Nrf2 results in decreased CC-IC frequency in vitro. Since transcription factors like Nrf2 are difficult to target, we instead targeted mechanisms that regulate Nrf2 activity. Nrf2 is significantly correlated with the epigenetic regulator histone acetyl transferase (HAT1) and studies show that acetylation of Nrf2 promotes enhanced Nrf2 activity. Treating CC-IC enriched Nrf2 knockdown cells with chemotherapy results in HAT1 upregulation. Furthermore, treating CC-IC enriched HAT1 knockdown cells with chemotherapy caused increased cell death and a decrease in CC-IC frequency in vitro. Another mechanism of CRC chemoresistance is the aggregation of p53, causing the loss of its pro-apoptotic function. It has previously been established that CBP/p300 bromodomain inhibition decreases protein amyloid-like aggregation. CBP/p300 regulates p53 through its acetylation, ubiquination, and bromodomain activity, however it has never been shown that CBP/p300 bromodomain inhibition results in a decrease in p53 disaggregation. We show that treatment of mutant p53 CRC cells with 5FU increases p53 aggregation and acetylation of p53 lysine K382, a binding site for the CBP/p300 bromodomain. By treating cells with the CBP/p300 bromodomain inhibitor, SGC CBP30 (CBP30), we decreased 5FU-induced p53 aggregation and restored the pro-apoptotic function of p53. p53 mutant cells treated with CBP30 became more sensitive to 5FU, while CBP30 had no significant effect on CRC viability in p53 knockdown cell lines. Therapeutically targeting mechanisms that drive chemoresistance in CRC will improve chemotherapeutic response and decrease relapse in CRC patients.

Keywords: aggregation
antioxidant
cancer
colorectal
Nrf2
p53
Advisor: O'Brien, Catherine A
Resolve - For Symphony Orchestra

Written as the thesis composition for the DMA in Composition degree, Resolve is simple in concept: it would be a musical composition that unravels at a glacial pace in one movement over the span of 16 minutes. By setting this conceptual limitation upon myself, I hoped to create a composition with a focus on melody, harmony, and counterpoint. The inspiration behind writing a very slow work for orchestra in part came from the music of John Luther Adams and Olivier Messiaen. Both composers are known for works which stretch over long periods of time and challenge the listeners’ ability to perceive the larger scale form. I especially admire the way these composers create extremely long lines that are suspended in beautiful harmony. In this work, harmony is created through the complex overlapping of individual melodic lines, which in turn create a harmonic field which slowly shifts as lines merge and disperse. The title Resolve reflects two important elements in the piece - first, the sense of slow determination that pervades the piece through its slow build up and secondly, the idea of long-term harmonic and musical resolution that comes in the form of two major climaxes. The work is ultimately a musical reflection on the crises of our time and attempts to capture the immensity of time through deliberately slow motion, allowing space for meditation and thought.

Keywords: Classical
Composition
Contemporary
Orchestra
Advisor: Palej, Norbert
To the 21st Century, and Beyond! Investigating the Practical Ways that Secondary School Teachers can Develop the “21st Century Competencies” in their Students

In this study, I aimed to investigate the practical ways that secondary school teachers in different subject areas could better develop the 21st century competencies – critical thinking and problem solving; innovation, creativity, and entrepreneurship; self-directed learning; collaboration; communication; and citizenship – in their students, as outlined by the Ontario Ministry of Education (2016; 2017), as well as the challenges they faced in their pursuit of developing the competencies. While many of the competencies have been encouraged over the past century in education and promoted in policy documents, teachers still struggle with how to most effectively develop the competencies in their students, and I was interested in observing the day-to-day experiences and approaches of my participants. To collect the data used in this qualitative case study, I conducted interviews with eight participants, followed by over sixty hours of in-class observations and ongoing document analysis. To wrap up the data collection, I concluded with another round of interviews before narrowing my final data analysis to five of the eight participants. Data collection took place over the 2017 and 2018 school year at my workplace, an independent school called Gates Tech in the Greater Toronto Area. From my data collection, the research participants felt that there were a few keys to success when it came to developing the competencies in their students. These characteristics included the importance of a supportive school culture and administration, the importance of establishing trust in the classroom, the necessity of co-constructing knowledge with students, viewing the curriculum as flexible, focusing on bringing the outside world into the classroom, having access to (and the confidence to use) multiple technologies and flexible spaces, rethinking assessment practices, and continuing to learn and reflect as a teacher. Challenges faced by the teachers in this study included overload, a fear of failure, a fear of pushback from students and parents, the pressure to be “all-knowing,” and the ongoing pressures to produce high test scores. Ongoing research and support are recommended to better support teachers and students as they pursue the development of the competencies in an ever-changing world.

Keywords: 21st century competencies
case study
constructivism
global competencies
secondary school
technology
Advisor: Hewitt, James
Wavelength-modulated Intravascular Differential Photoacoustic Radar for Interference-free Detection of Vulnerable Plaques in Atherosclerosis

As lipid (or cholesterol) composition of atherosclerotic plaques is considered to be one of the primary indicators for plaque vulnerability, a diagnostic modality that can sensitively evaluate their necrotic core is highly desirable in atherosclerosis imaging. In this regard, intravascular photoacoustic (IVPA) imaging is an emerging plaque detection technique that provides lipid-specific chemical information of diseased arterial walls. Within the near-infrared window, a 1210-nm optical source is usually chosen for IVPA applications because lipid exhibits a strong absorption peak at that wavelength. However, other arterial chromophores also show some degree of absorption near 1210 nm and generate undesirably interfering PA signals upon the same optical excitation. In this study, a novel wavelength-modulated differential photoacoustic radar (IV-DPAR) modality was introduced as an interference-free lipid detection technique for a more accurate and reliable diagnosis of plaque progression. Unlike mainstream IVPA modalities that are based on pulsed optical sources, IV-DPAR utilizes low-power intensity-modulated continuous-wave (CW) laser diodes for optical excitation. With frequency-swept optical modulation and the matched-filter pulse compression processing, IV-DPAR was demonstrated to perform spatially-resolved functional imaging on lipids with excellent signal-to-noise ratio (SNR). Signal processing algorithms were investigated to explore the novel phase-filtered amplitude (PFA) channel. By encoding the phase-derived statistical probability of the presence of lipids on the conventional amplitude channel, the PFA channel could significantly enhance various imaging parameters such as SNR and axial resolution. Most importantly, the simultaneous modulation of the two CW lasers in IV-DPAR facilitated the unique differential dual-waveform engineering technique that could efficiently suppress undesirable background absorptions and system noise to approximately zero baselines, while dramatically improving detection sensitivity and specificity toward lipids, the primary ingredient of a plaque necrotic core. When co-registered with clinically-accepted intravascular ultrasound imaging, IV-DPAR could not only locate but also quantitatively characterize the lipid contents of plaques in porcine and human atherosclerotic arteries, regardless of their size and depth.

Keywords: Atherosclerosis
Differential imaging
Photoacoustics
Advisor: Mandelis, Andreas
An Investigation of the Distribution of Ozone-depleting Substances in the Upper Troposphere and Lower Stratosphere

Stratospheric transport in global circulation models and chemistry-climate models is an important component in simulating the recovery of the ozone layer as well as changes in the climate system. The Brewer-Dobson Circulation is not well constrained by observations and further investigation is required to resolve uncertainties related to the mechanisms driving the circulation. This work has assessed the specified dynamics mode of the Canadian Middle Atmosphere Model (CMAM30) by comparing its output to the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) profile measurements of CFC-11, CFC-12, HCFC-22, and N2O. In the CMAM30 simulation, the meteorological fields were nudged using the ERA-Interim Reanalysis and a specified tracer was employed for each halocarbon species, with hemispherically-defined surface measurements used as the boundary condition. This modified halocarbon experiment is known as CMAM30HR. A comprehensive sampling technique along the line-of-sight of the ACE-FTS measurements has been utilized to allow for direct comparisons between the simulated and measured tracer concentrations. Stratospheric transport has been investigated using CFC-11, CFC-12, and N2O. The model consistently overpredicts the concentrations of these tracers in the lower stratosphere, particularly in the Northern Hemisphere winter and spring seasons. The three mixing barriers investigated, namely the polar vortex, the extratropical tropopause, and the tropical pipe, show that there are inconsistencies between the measurements and the simulations. It was found that the simulation under- predicts mixing efficiency in the tropical lower stratosphere during the June-July-August season. The CMAM30HR simulations and the ACE-FTS measurements of HCFC-22 have also been evaluated. ACE-FTS HCFC-22 observations exhibit a small low bias compared to instruments that use a similar measurement technique. However, when compared to in situ measurements, ACE-FTS exhibits a high bias. In general, CMAM30HR exhibits a low concentration bias below approximately 70−30 hPa and a high bias above 30 hPa compared to ACE-FTS. However, the HCFC-22 comparison reveals a peak in differences between approximately 100 hPa and 50 hPa that is not consistent with the previous comparisons of halocarbon concentrations; potential explanations of the discrepancy are discussed. The most recently available ACE-FTS data are also presented and discussed.

Keywords: chlorofluorocarbons
hydrochlorofluorocarbons
stratospheric transport
Advisor: Walker, Kaley A
Artificial Intelligence Planning Techniques for Emulating Agents with Application in Social Services

This thesis investigates the problem of emulating seemingly irrational behaviour with the use of a rational reasoner. This thesis adopts the position that human behaviour is rational but our reasoning process is bounded. To an observer with an equally rational reasoning process but different bounds, an agent's behaviour may seem irrational. The approach presented in this thesis extends a rational reasoner in classical artificial intelligence planning, STRIPS, using three theories from psychology and economics. The first theory, bounded rationality, limits an agent's reasoning ability with human-like bounds. The second theory is Maslow's hierarchy, which is used to organize and rank an agent's goals during the process of plan creation and execution. The third theory is the emotional cycle of change which is used as a nonlinear measure of expectation of success, triggering goal reranking and replanning processes during plan execution. By adopting these methods, human behaviour emulation is viewed as a classical planning problem with a non-linear evaluation function. The resulting system, Bounded Rational Agent MotivAtions framework (BRAMA), emulates trajectories of agent behaviour. The trajectories simulate agent usage patterns for various services to meet the agent's goals. The target application of BRAMA is in social services, simulating the response of homeless clients to the Housing First intervention program in Calgary, Canada. The results of the simulation can be used by policy makers to evaluate the effectiveness of alternative programs before they become policy.

Keywords: behavioral psychology
bounded rationality
goal reasoning
ontology
planning
simulation
Advisor: Fox, Mark S
Grüninger, Michael