VictorJuiz/thesis huggingface dataset:
Finite Difference Methods in Imaging and Inverse Problems
Keywords: feature detection
FIR filter design
image processing
inverse problems
numerical differentiation
total variation

This thesis establishes a mathematical toolbox for numerical difference (ND) approximation that can be applied in numerous imaging problems such as restoration and feature detection. The proposed framework is based on integrating the interpolating power polynomials with maximally-linear-flat design methods to regulate the desired ND transfer functions in Fourier domain. Variety of filters are extracted that are capable of addressing different orders of differentiation, accuracies, and cut-off frequency parametrization. The numerical stability of the designed coefficients are highly robust through different filter orders. The second phase of this thesis studies a wide range of imaging applications that utilize the proposed ND filters to avoid unnecessary complexities in practical designs. One of the main applications is studied over the total variation (TV) regularization, which employs functional derivatives to regulate problems in image restoration. We propose to approximate the TV norm space by means of the latter ND filters. Proper mathematical foundations are presented to understand the performance of the TV models in different signal transitions. In particular, we focus on de-noising and compressed video sensing applications and illustrate with a number of experiments to study the impact of alternative ND methods. A proper convex minimization algorithm is proposed to utilize the latter filters to recover images from their degraded measurements. Furthermore, the problem of optical flow in computer vision is considered in this thesis. A comparative study is represented over the well-known taxonomy that links lowpass ND design to the gradient constancy constraints and avoid pre-processing steps for image smoothing. Curvature estimation and edge detection problems in imaging are also studied to modify the pertinent feature estimation from noisy sampling. The experimental evaluations on selected imaging problems outperform the existing state-of-the-art methods.
Three Essays on the Penalty Doctrine
Keywords: Contract Law
Feminist Legal Theory
Good Faith
Relational Theory
Remedies
Unconscionability

The penalty doctrineâ that rule of contract law that a clause requiring payment of a penalty in case of breach will not be enforcedâ is a riddle of contract theory. It seems to up-end the primacy of freedom of contract over judicial imposition. In three essays, I consider three ways to understand the doctrine: as proscribing unconscionability, as requiring good faith, and as enforcing the courts' policy on remedies. Each approach fails, and I connect these failures to contract law's structure. In order to understand the way the penalty doctrine straddles the border between freedom and regulation of contract, we must take a step backward into a theoretical stance that encompasses both. A relational theory of the self offers such a stance. This thesis ends with the suggestion that relational theory is able to synthesize the dualisms and boundaries that the penalty doctrine defines.
Mapping the Assembly of Muslim Exceptionality and Exceptional Muslims in Colonial Modernity. Ismaili Muslim Encounters through Discourses, Bodies and Space in the Canadian Colonial Nation
Keywords: Muslims
Canada
Multiculturalism
Ethnicity/Race
Gender
Pluralism
Modernity
Exceptionality

What is produced through the encounters with specific “modern Muslims” in the Canadian colonial nation state? In the last decade in Canada there have been efforts to engage in a demarcation between Muslims and other racialized groups in order to define some bodies as part of the nation whilst others outside of the national imaginary. This is particularly important in the nation-building project of Canada in retaining a tolerant, liberal and multiculturally celebrated society. This critical feminist ethnography makes visible the encounters and present economies of sociopolitical currents in which the Ismailis, as a Muslim community and gendered ethnicized bodies, move and animate in Canada as a settler colonial race formation as well as in a broader geography of Muslim social and cultural politics. It is in the constitutions and movements of their collective subjectivities as a religious community and in their ethnicized gender, race, and class difference that they locate and engage in interlocking systems of power rooted in nation, empire, colonialism, modernity, and religion. This thesis aims to show that in order to make sense of Ismaili encounters it is necessary to map multiple pasts and multiple presents, which they are part of and that shape them. Different from most studies on the Ismailis in Canada, I also place Ismailis’ entrance and settlement in Canada within a broader dynamic of colonial power and management of racialized peoples and within current shaping of Muslims as racial constructs. This thesis argues that Ismailis are becoming Muslims of “exceptionality.” First, through their high level public encounter with the colonial settler Canadian nation state; second through their intersecting encounters with other Muslims and non-Muslims in Canada; and third in their encounters with each other as Afghan, Pakistani, and Indian Ismailis. These three encounters intervene the discourse of pluralism of which the Ismailis are becoming advocates and Canada its global exemplar. It is through seeing what is produced between these “bodies” in specific moments of their meeting in Canada that, bodily, spatial and discursive practices of social relationship making emerge. These show the paradoxical outcomes of embodying modern coloniality and Muslim exceptionality.
Equity and Community Art Education in the University: The Challenges, Possibilities, Implications of Learning in A Littoral Zone (A Critical Arts-informed Case Study)
Keywords: Art Education
Arts Research
Community Engagement
Equity
Social Justice
Storytelling

This critical, arts-informed case study examines how issues of equity emerge in the case of a community-arts certificate offered at a large urban Canadian university. A combination of arts-informed (poetry, micro-narratives, still/moving photography) and conventional qualitative methods of data collection, analysis, and representation is used with a focus on case study as storytelling for social justice. Community art has emerged as a relatively new credentialized field for teaching, practice, and research within the university/art school in Canadian contexts. Community arts courses in post-secondary settings often attempt to integrate collaborative grassroots and/or activist arts practices and initiatives for social justice into the context of the academy. In response, social justice arts practitioners outside the academic context have voiced concerns about access and credentialism within community-engaged art, and fine arts educators within the academy have raised questions about the artistic quality, rigor, and evaluation of practices that resist traditional disciplines, canons, and conceptions of art. This study explores how one particular community art certificate contributes to debates about legitimacy and equity in the fine arts and arts education: “What is art and who makes it? Where and why does art happen? How should art be cultivated?” The metaphor of a littoral zone is used throughout to examine the certificate as a liminal space that oscillates between different disciplinary paradigms, pedagogical approaches, and ways of knowing, being and doing. The research examines how issues of equity emerge in this case and how strategies that support equity are embraced (possibilities) or resisted (challenges) within the certificate and within the University’s cultures, practices and structures. A selection of the sites of learning (university, classroom, practica), relationships (interdisciplinary, institutional/organizational, interpersonal) and experiences (students) that the certificate embodies is examined. The research provides insight into how this particular story might address and intervene in the dominant conventions and relations of fine arts practice in Canada as well as contributing to discussions and movements for equity in Canadian post-secondary fine arts education and community-engaged arts practices.
Silicon Ring Modulators for High-speed Optical Interconnects
Keywords: Coupling modulation
PAM
QAM
Ring modulators
Silicon Photonics
Small-signal

This thesis presents research contributions in the area of ring modulator modeling, design, and characterization. These include small-signal modeling of the intracavity and the coupling modulated ring modulators, optimization of intracavity ring modulator rib-to-contact distance as well as proposal, design, and fabrication of PAM-N and QAM-N modulators. Accurate modeling of the ring modulator small-signal response is essential for designing a modulator. In this thesis, a closed-form expression for small-signal response of an intracavity ring modulator is derived and verified by measurement results. The pole-zero representation of the transfer function illustrates dependency of the ring modulator frequency response upon parameters such as electrical bandwidth, coupling condition, optical loss, and sign/value of the laser detunings. Using the developed small-signal model and through measurement of the fabricated intracavity ring modulators in IME A*Star process, electrical and optical trade-offs of rib-to-contact distance are analyzed. Key parameters such as extinction ratio, insertion loss, transmission penalty, and bandwidth are compared quantitatively. We show that at 4dB extinction ratio, decreasing the high doped region distance to rib from 800nm to 350nm increases the bandwidth by 3.8Ă while increasing the insertion loss by 8.4dB. Small-signal response of the coupling-modulated ring resonator is also obtained and is compared with the intracavity ring modulator response. Based on number of poles and zeros, it is shown that unlike the intracavity ring modulator, the coupling-modulated ring resonator does not have the optical bandwidth limitation. Coupling modulation in a ring resonator is then used to present a new method for optical PAM modulation. The response of this modulator is optimized in terms of linearity for both reverse and forward-biased cases. This modulator can operate for long haul communication with its data rate only limited by the MZI bandwidth. Lastly, a compact structure for DAC-free optical QAM modulation based on the coupling modulated ring resonator is proposed and fully analyzed where various key design considerations are discussed. Output level linearity is also studied where we show that linearity among levels is achievable with two segments in QAM-16 while an additional segment may be required in QAM-64.
Identification of Epstein-Barr virus proteins that inhibit the DNA damage response
Keywords: DNA damage response
Epstein-Barr virus

Epstein-Barr virus (EBV) is a common herpesvirus that is the causative agent of mononucleosis and can also induce a variety of B cell lymphomas and carcinomas. To promote viral replication and cell survival, EBV is known to manipulate the cellular DNA damage response (DDR). To date there have only been a few studies on the interplay between EBV and the DDR and the functions of many EBV proteins remain uncharacterized. In this study, we screened a library of 47 EBV proteins for the ability to interfere with the formation of 53BP1 foci, a late step in the DDR, in response to etoposide-induced DNA damage. An uncharacterized tegument protein, BKRF4, was identified as an inhibitor of the DNA damage response. By studying the effect of BKRF4 on the steps of the DDR, it was shown that BKRF4 had no effect on the induction of γ-H2AX, but blocked the subsequent step at which histones H2A/H2AX become polyubiquitylated, which in turn inhibited the recruitment of 53BP1. To identify the host interactions of BKRF4, an affinity purification-mass spectrometry experiment was performed and identified histones as the most prevalent interacting partner. In keeping with this finding, an in vitro binding assay performed with purified BKRF4 and purified histone octamers showed the direct interaction between BKRF4 and histones. This interaction predicts that BKRF4 will localize to cellular chromatin, which was confirmed by both fluorescent microscopy and biochemical fractionation. BKRF4 contains a highly acidic region and this fragment of the protein was shown to be responsible for the chromatin interaction and DDR inhibition. Therefore, our results indicate that BKRF4 is targeted to cellular chromatin through a direct interaction with histones, where it can modulate at least some histone functions including the DDR.
Number Fields with Large Minimal Index
Keywords: Effective Diophantine approximation
Index forms
Minimal index of number fields

The index of an integral element α in a number field K with discriminant DK is the index of the subring Z[α] in OK. The minimal index m(K) is taken over all α ∈ OK that generate the field. This thesis proves results of the form m(K) << |DK|U for all Galois quartic fields and composites of totally real Galois fields with imaginary quadratic fields, and of the form m( K) >> |DK|L for infinitely many pure cubic fields, both types of Galois quartic fields, and the same composite fields, with U and L depending only on the type of field. The upper bounds are given by explicit elements and depend on finding a factorization of the index form, while the lower bounds are established via effective Diophantine approximation, minima of binary quadratic forms, or norm inequalities. The upper bounds improve upon known results, while the lower bounds are entirely new. In the case of imaginary biquadratic quartic fields and the composite fields under consideration, the upper and lower bounds match.
Acetylated Hemoglobin Bis-Tetramers: From Chemical Designs to Physiological Impacts
Keywords: Bio-orthogonal
Bis-tetramer
HBOC
Hemoglobin
Hypertension

My research centers around the development of chemical strategies that enhance the production of hemoglobin bis-tetramers. Hemoglobin-based oxygen carriers (HBOCs) are molecules that can carry oxygen in the circulation without being contained within red blood cells. Clinical trials of early HBOCs note that the use of these materials was associated with increased risks of cardiovascular dysfunction and death. The adverse effects appear to result from removal of nitric oxide (NO), a signal required to maintain vasorelaxation. Recent pre-clinical studies show that a hemoglobin bis-tetramer do not induce such side effects. However, due to constraint on the chemical process, improved methods to produce this class of materials is necessary for further in vivo characterizations. A potential alternative route to make hemoglobin bis-tetramer is through a bio-orthogonal copper catalyzed azide alkyne cycloaddition (CuAAC) between two azide-functionalized hemoglobin tetramers and a bis-alkyne chemical linker. The efficiency of the coupling process appears to be limited by the introduction of azide-containing cross-link, which gives a mix of reactive and non-reactive azides. I developed a chemical blocking strategy to push the azide-containing cross-link to form in the reactive state. My efforts led to the formation of a novel acetylated hemoglobin bis-tetramer (BT-acHb) with up to 65% yield. In vitro characterization of BT-acHb showed that the chemical modifications did not significantly perturb the protein’s structure or oxygen carrying abilities. Further study on the nitrite reductase activity of the derivatives were carried out, as this vasodilatory feature may act as an in situ source of NO. I find that BT-acHb exhibit enhanced ability to mediate the nitrite-NO conversion. To study whether the chemical modifications necessary to improve the production of bis-tetramer affects its circulatory behavior, I examined the in vivo effects of BT-acHb in the best animal models available. Animal studies of BT-acHb indicate that HBOCs, produced using the efficient bio-orthogonal chemistry described in this dissertation, are safe and functional oxygen carriers in the murine circulation.
Symmetrical Elements in the Piano Music of Einojuhani Rautavaara
Keywords: Contemporary music
Einojuhani Rautavaara
Finnish composer
Keyboard symmetry
Piano
Symmetry

Einojuhani Rautavaara (1928 – 2016) is regarded as one of the most internationally successful composers from Finland since Jean Sibelius. He is widely known for his pluralistic compositions that do not follow a linear progression of stylistic development and that exhibit a synthesis of seemingly contradictory compositional styles in his mature works. Despite the rapid changes of styles, Rautavaara retains certain characteristics that set his music apart from that of others. One of these elements that remained consistent throughout his career is his fascination with symmetry. From the Three Symmetrical Preludes during his student years to his late piano miniatures, symmetrical compositional tools such as the bilateral keyboard symmetry remained a key component in his piano works. Although Rautavaara’s piano output is small compared to other genres, it is scattered throughout various stylistic periods in his life, making it possible to observe the similarities and changes in his writing. The goal of this research is to observe and study how the composer developed and utilized symmetry in his compositions through analysis of selected solo piano works from the early to the late period. As the research centers on symmetry, the works chosen for analysis will be the ones that contain significant amounts of symmetrical writings, namely the Three Symmetrical Preludes (1949–50), selections from Etudes (1969), Piano Sonata No. 1 (1969), Narcissus (2001), and Mirroring (2014). This research also provides an opportunity to study Rautavaara’s lesser-known piano works, as well as providing a first look at Mirroring, his very last work for solo piano. The concluding chapter considers the symbolisms in symmetry as well as interpretive choices and pedagogical merits of symmetrical structures in Rautavaara’s solo piano music.
Transient Receptor Potential Melastatin Channel-2 Mediates Microglial Activation and Migration After Injury
Keywords: Cell Injury
Cell Migration
Cerebral Development
Microglial Activation
TRPM2
Uropod

TRPM7 and TRPM2 are non-selective cation channels of the Transient Receptor Potential channel superfamily and ‘melastatin’ subfamily. Each channel has gained attention for the role they play in mediating ischemic cell death in brain tissue, however their physiological expression and potential roles in the developing brain remained elusive. Real-time PCR assays revealed that TRPM7 mRNA expression peaks in the cortex 2-weeks after birth which correlates most closely with a period of rat brain development associated with neurite outgrowth. TRPM2 mRNA was most highly expressed in microglia and paralleled the perinatal expression timeline for microglial infiltration and maturation in the rat brain. These developmental expression profiles indicated a potential role for TRPM2 in regulating microglial activation. Since calcium regulation is important for cell function and migration, a specific role for TRPM2 in regulating cell migration after injury was investigated by time-lapse imaging of an in vitro model of cell migration and injury called ‘necrotaxis’. Primary microglial cells isolated from Trpm2-/- mice exhibited impaired migration, resulting in the loss of persistent directional migration. A high colocalization between Rab11 (recycling endosomes) and β1-integrin was also found in Trpm2-/- microglia, suggesting that TRPM2 affects the overall migration of microglial cells by mediating tail detachment via the trafficking or recycling of integrins. To determine whether the effects of knocking out TRPM2 on microglia persisted in an in vivo model of injury, Iba1+ immunoreactivity was assessed in wild-type and Trpm2-/- mice after inducing acute ischemic stroke. Immunohistochemistry analyses revealed a lower number of activated microglia in Trpm2-/- mice after acute ischemia compared to wild-type mice, suggesting that TRPM2 affects the recruitment of microglia to the site of injury. This study provides evidence that links TRPM2 to tail detachment via integrin trafficking/recycling which in turn affects the migration of microglial cells. TRPM2 may therefore be a good target to mitigate inflammation after stroke and other neurodegenerative diseases, when excessive microglial activation or proinflammatory processes may negatively impact brain recovery.
IMMIGRANT NON-NATIVE ENGLISH SPEAKING TEACHERS IN TESOL: THE NEGOTIATION OF PROFESSIONAL IDENTITIES
Keywords: Canada
Immigrant Teachers
Non-Native English Speaking Teachers
Professional Identity
Teacher Certification
TESOL

This study examined how immigrant non-native English speaking teachers (INNESTs) in the field of TESOL (Teachers of English to Speakers of Other Languages) negotiate professional identities within the framework of a TESOL certification program. Three aspects of their identities were investigated: language-related identity, disciplinary identity, and teaching self-knowledge. Two groups of participants were recruited. The first group (115 in number) had already completed a TESOL program and were ESL teachers. The second group (five in number) were all registered in a full-time TESOL program to become certified to teach ESL in Ontario, Canada. A complementary, concurrent component mixed methods research design was adopted. The quantitative and qualitative data were collected through various data collection strategies. The analysis is informed by a number of theoretical concepts: identity, critical pedagogy, sociocultural theory, and teacher cognition. The main findings are as follows. First, INNESTs viewed the native speaker construct as consisting of multiple dimensions. The findings suggest that the construct is complex, contextual, dialogic, dynamic, ideological, intersecting, multifaceted, negotiable, relational, situated, and shifting as a developmental process as opposed to a fixed unitary state. Despite that, INNESTs continue to experience mostly conventional realizations of the construct. Second, institutional certification serves as a symbolic discourse of de-professionalization for INNESTs applying for certification. INNESTs reacted to such discourse in different ways, accepting and internalizing or questioning and resisting it. The certification process did not distinguish the experienced INNESTs from their novice native-born teacher candidates; but it did provide them with recognition, acceptance, and legitimacy in the professional TESOL community. Third, the majority of the INNESTs reported a high level of confidence by presenting a generally positive self-image. The findings highlight the importance of self-image in negotiating teaching knowledge in the TESOL community. Moreover, INNESTs’ cognition is influenced by conflicts they experience reconciling their new teaching context, their past learning experiences and teaching beliefs, as well as their instructional decisions. Implications regarding ways to facilitate positive identity construction and professional integration are discussed.