VictorJuiz/thesis huggingface dataset:
Molecular Mechanisms of the Cooperation between Rac1/1b GTPases and the Canonical Wnt Signaling Pathway in Colorectal Cancer
Keywords: Rac1
Wnt
Colon cancer
Rac1b

Aberrant activation of the canonical Wnt signaling pathway accounts for the vast majority of colorectal cancers. The Rac1 GTPase is overexpressed in colon cancer, and its splice variant, Rac1b, is preferentially expressed in colon tumours. Rac1 and Rac1b have both been previously shown to crosstalk with the canonical Wnt signaling pathway in colon cancer; however, the specific means by which this crosstalk occurs were unclear. This study examines the molecular mechanisms of Rac1/1b in the cooperation with canonical Wnt signaling in colon cancer. In a colon cancer cell line with dysregulated Wnt signaling, the constitutively active Rac1 mutant, V12Rac1, was observed to transcriptionally upregulate the expression of a gene set associated with cellular migration. Further, V12Rac1-mediated promotion of cell migration was dependent on its nuclear localization. Previous work in our lab has shown a Rac1-specific activator, Tiam1, is present in the nucleus at the promoter of Wnt target genes upon Wnt3a stimulation; and that exogenous introduction of Tiam1 increased the expression of a Wnt-responsive reporter (TopFlash). Given the importance of nuclear localization of Rac1 in the promotion of tumourigenic processes, we demonstrated that knockdown of endogenous Tiam1 reduced TopFlash expression, proving reverse specificity and strengthening the evidence of a nuclear role for Rac1. Since some functional differences exist between Rac1 and Rac1b, we also examined Rac1b for transcriptional targets following induction, and identified the RhoA effector, ROCK2, which has been previously associated with cell migration. ROCK2 demonstrated a positive correlation with Rac1b transcript expression in primary colon tumours as compared to matched normal tissue specimens. Interestingly, the observed induction in ROCK2 transcript did not translate into a detectable change in protein expression or kinase activity. Like Rac1, Rac1b also promotes cellular motility, which is dependent on nuclear localization. Cell migration can be negatively regulated by E-cadherin. Following Rac1b knockdown in HT29 cells, we show that Rac1b might contribute to motility through upregulation of the E-cadherin-repressor, Slug. Taken together, we provide greater insight into the mechanistic roles of Rac1 and Rac1b in transcriptionally regulating target genes to promote cellular processes, such as cell migration, in colon cancer with dysregulated canonical Wnt signaling.
Is Hearing Believing? Perception of Online Information Credibility by Screen Reader Users who are Blind or Visually Impaired
Keywords: Credibility perception
Blind or visually impaired
Web accessibility
Everyday information practices
Online participation

While credibility perception on the Web is a well-researched topic across multiple disciplines, extant studies have not considered nonvisual modalities of Web access. This research explores how Web users who are blind or visually impaired perceive the credibility of online information and how the screen reader used by them to interact with the Web mediates the process. Credibility perception was studied in the context of the screen reader users’ everyday information practices, examining in depth the effect of Web accessibility on their online information interactions, information practices and credibility perception. Adopting an exploratory approach, a sequential multimethods research design was used. Between April and July 2008 data were collected from adult screen reader users residing in Ontario, Canada through an electronic questionnaire survey (N=60) to identify salient issues, which were then examined deeper through semi-structured interviews with a subsample (N=13) during June 2009. Hands-on online information activities (with participant observation and think-aloud protocol) were also conducted during the interview session. Primary findings emerged through qualitative content analysis of descriptive data, with quantitative results guiding and supplementing the analysis. Online information credibility perception is found to be a dynamic and social process. It is governed by users’ assumptions based on their past experiences, personal knowledge/beliefs and social inputs. Assumptions evolve over time and usage into personal heuristics. The credibility perception process spans three phases—prediction, evaluation and corroboration—permeating the information seeking, using and sharing practices of users. Evaluation of website and web content depends on users’ online interaction proficiency and is bounded by the interface affordances provided by the screen reader and the amount of meta-information provided by the websites for interpreting visual/spatial features. Community support scaffolds users towards more effective technology management and credibility perception. Therefore, promoting inclusion in the online participatory culture will enhance the information practices of screen reader users.
What are you in the dark? The Transformatiive Powers of Manitouminasuc upon the Identities of Anishinabeg in the Ontario Child Welfare System
Keywords: Aboriginal Identity
Child Welfare
Relationships
Social Change
Philosophy
Social Policy
Personal Development
Culture
Feminism

The purpose of this qualitative study is to explore, describe and examine how the child welfare experience affects the personal and social identities of Anishinabe participants. Contextual realities, specifically the cultural and child welfare contexts, and how participants situate themselves in those realities, are explored. A Critical Ekweism conceptual framework is used to inform the design of the study and analyze the unique experiences of participants. The framework seeks to respect and understand the unique historical backgrounds and perspectives of participants as they critically evaluate their contexts as knowers and experts of their own experiences. While participants collectively identified existing dilemmas and practices, they also decided to actively think of ways to re-address and to positively transform these dilemmas and practices. Methods of inquiry included the Aboriginal Circle paradigm that is interwoven with Phenomenological procedures. The Aboriginal Medicine Wheel was used as an organizational tool to illustrate and explain study findings, and Phenomenological procedures were used to explore the meanings participants append to their experiences. Both sharing circles and individual interviews were used to collect data from twenty-seven participants who were involved in the child welfare system at the time of the study. Some were living in Northern Ontario, others in a large city. Data were transcribed and Grounded Theory coding procedures used to analyze the data and identify themes. Four main themes emerged: Place of Understanding’, ‘Place of Disconnection’, ‘Place of Identification,’ and ‘Place of Reconnection’ to represent the sacred knowledge-making spaces where participants through the Reality Circle make sense of their contexts. The meanings that underpin each of these sacred spaces are discussed. An analysis of the meanings of these four sacred spaces further describes how participants’ personal and social identities are juxtaposed in their cultural and child welfare contexts. Of interest is how participants’ child welfare experiences affect their cultural and parenting identities. Child welfare practices are interpreted in terms of parent, social work and First Nations Community responsibilities. A diagram depicting these responsibilities is presented as the ‘Anishinabe Identity Circle.’ The study is significant for the social work profession because an Anishinabe approach to ‘doing’ social work with this particular group of participants is developed and has implications for Aboriginal-based Theory and Aboriginal-based support and policies. Even though this is a small step towards changing some of the existing practices in the Child Welfare System, it may pave the way for larger and more constructive social changes for participants and their children in the future.
The Construction of Self-identity and Positive Behavioural Change in Pregnant and Parenting Young Women
Keywords: identity
narrative
positive youth development
early motherhood

The purpose of this mixed method study was to investigate the relationship between the narrative construction of self-identity and positive change in antisocial behaviour in pregnant and parenting young women. It focused on two related aspects of identity development: (1) individuals’ conceptualizations of their personally salient self-values; and (2) “self-action coherence”: the process of constructing self-narratives that establish coherence between one’s personally salient self-values and behaviour. This study also included a qualitative exploration of how becoming a mother in adolescence and early adulthood is related to processes of identity development and behavioural change. Participants were 27 pregnant and parenting young women (ages 16 to 22) recruited from youth-serving agencies in Toronto, Ontario. Participants completed a questionnaire on history of engagement in antisocial behaviour and a semi-structured interview that explored self-identity and critical life experiences. Analyses of participant interviews suggest that positive behavioural change in pregnant and parenting young women is related to active engagement in self-reflection motivated by a convergence of meaning gleaned from a variety of life experiences, including the transition to motherhood. Quantitative findings suggest that: (1) an orientation to relational values is related to lower reported recent engagement in antisocial behaviour; (2) self-action coherence develops across adolescence and early adulthood; and (3) self-action coherence is related to reported positive behavioural change. Overall, the findings suggest that an orientation to relationships is important for establishing positive patterns of behaviour and that positive behavioural change in pregnant and parenting young women involves a process of constructing personally salient self-values and establishing behaviours that cohere with these values. The findings have theoretical implications relating to identity development in adolescence and early adulthood and its relations to behavioural functioning. The findings also have implications for applied work with pregnant and parenting young women with histories of antisocial behaviour.
Magnetic Resonance Imaging to Identify Intraplaque Hemorrhage and Define its Location in Complicated Carotid Artery Plaques
Keywords: Intraplaque hemorrhage
Magnetic Resonance Imaging

Atherosclerotic plaque (AP) composition is an important factor influencing plaque rupture. Intraplaque hemorrhage (IPH) is a marker of complicated-plaque formation, responsible for many of the clinical manifestations of atherosclerotic disease. Magnetic resonance imaging (MRI) has emerged as a modality to image carotid AP. The in-vivo high-resolution MR imaging of carotid complicated-plaque forms the basis of this thesis. In the first part, Magnetic Resonance Imaging of Intraplaque Hemorrhage (MRIPH), an in-vivo high-spatial-resolution 3-dimensional MRI sequence specifically designed to depict complicated-plaque in the carotid arteries is described. MRIPH was applied, as compared with histologic analysis (gold standard), to demonstrate that T1-hyperintense intraplaque signal represented blood products. Strong agreement was seen between T1-hyperintensity and histologically-identified hemorrhage, with high sensitivity/specificity/positive- and negative-predictive values for T1-hyperintense detection of hemorrhage. While IPH increases plaque rupture risk, high degrees of calcification promote stability. Calcium can generate T1-hyperintensity in some gradient-echo (GRE) sequences. Therefore, distinction between these two components is crucial. In the second part, T1-hyperintensity in MRIPH was shown to be almost exclusively due to hemorrhage and not calcification by directly comparing in-vivo T1-hyperintensity with calcification in ex-vivo specimens imaged with microCT. T1- hyperintesity showed very good albeit inverse agreement with calcification and excellent agreement with lack of calcification as seen on microCT. IPH is thought to be the result of rupture/leakage of the vasa vasora. In the third part, we tested the hypothesis that if IPH were due to vasa vasorum rupture/leakage, the majority of the IPH would be associated with the adventitial rather than the luminal surface of the plaque. Deep (closer to vessel wall) and superficial (closer to vessel lumen) regions of complicated plaques were identified. Very good inter-rater agreement was seen for the location of IPH using MRIPH, with IPH being more frequently present in the deeper compared to superficial segments of the plaque. In summary, an in-vivo MR technique to detect IPH at high spatial-resolution in carotid complicated-plaque was developed; demonstrating T1-hyperintensity in MRIPH is the result of IPH and not calcification. The predilection of IPH for the deeper segments of the plaques suggests that IPH is due to vasa vasorum rupture/leakage.
Life in a Body: Counter Hegemonic Understandings of Violence, Oppression, Healing and Embodiment among Young South Asian Women
Keywords: Embodiment
Young South Asian Women
Yoga
Violence

This study is an investigation of embodiment. It is informed by the experiences and understandings of health, healing, violence and oppression among 15 young South Asian women living in Toronto, Canada. Their articulation of the importance of, and difficulties associated with, health and healing in contexts of social inequity contribute to understandings of embodiment as co-constituted by sentient and social experience. In my reading of their contributions, embodied learning – that is, an ongoing attunement to sentient-social embodiment – is a counter hegemonic healing strategy that they use. Their experiences and insights support the increasingly accepted claim that social inequity is a primary determinant of health that disproportionately disadvantages subordinated people. Furthermore, participants affirm that recovery and resistance to violence and oppression and its consequences must address sentient-social components of embodiment simultaneously. In this study, Yoga teachings provide a framework and practice to investigate embodiment and embodied learning. Following 12 Yoga workshops addressing health, healing, violence and oppression, I conducted individual interviews with 15 workshop participants, 3 Yoga teachers and 2 counsellor / social workers. Participants discuss Yoga as a resource for addressing mental, physical, emotional and spiritual consequences of violence and oppression. They resist New Age interpretations of Yoga in terms of individualism and cultural appropriation; they also challenge both New Age and Western biomedicine for a lack of attention to the consequences of social inequity for health and healing. This study considers embodied learning as an important healing resource and form of resistance to violence and oppression. Scholarship addressing embodiment in sociology, health research, anti-racism, feminism, anti-colonialism, decolonization and Indigenous knowledges are drawn upon to contextualize the interviews. This study offers insights relevant to health promotion and adult education discourse and policy through a careful consideration of the embodied strategies used by the participants in their nuanced negotiations of social inequity and pursuits of health and healing.
The Multivariable Alexander Polynomial on Tangles
Keywords: Knot Theory
Multivariable Alexander Polynomial

The multivariable Alexander polynomial (MVA) is a classical invariant of knots and links. We give an extension to regular virtual knots which has simple versions of many of the relations known to hold for the classical invariant. By following the previous proofs that the MVA is of finite type we give a new definition for its weight system which can be computed as the determinant of a matrix created from local information. This is an improvement on previous definitions as it is directly computable (not defined recursively) and is computable in polynomial time. We also show that our extension to virtual knots is a finite type invariant of virtual knots. We further explore how the multivariable Alexander polynomial takes local information and packages it together to form a global knot invariant, which leads us to an extension to tangles. To define this invariant we use so-called circuit algebras, an extension of planar algebras which are the `right' setting to discuss virtual knots. Our tangle invariant is a circuit algebra morphism, and so behaves well under tangle operations and gives yet another definition for the Alexander polynomial. The MVA and the single variable Alexander polynomial are known to satisfy a number of relations, each of which has a proof relying on different approaches and techniques. Using our invariant we can give simple computational proofs of many of these relations, as well as an alternate proof that the MVA and our virtual extension are of finite type.
A Theory of Shared Understanding for Software Organizations
Keywords: software development
coordination
communication

Effective coordination and communication are essential to the success of software organizations, but their study to date has been impaired by theoretical confusion and fragmentation. I articulate a theory that argues that the members of software organizations face a constant struggle to share and negotiate an understanding of their goals, plans, status, and context. This struggle lies at the heart of their coordination and communication problems. The theory proposes an analysis of organizational strategies based on four attributes of interaction that foster the development of shared understanding: synchrony, proximity, proportionality, and maturity. Organizations that have values, structures, and practices which facilitate these qualities find it easier to coordinate and communicate effectively. This argument has serious implications for traditional concepts in our literature. Project lifecycle processes and documentation are poor substitutes for informal but unscalable coordination and communication mechanisms. Practices and tools are valuable to the extent that they enable the development of shared understanding across our criteria. Co-location and group cohesion take advantage of the four criteria and therefore have direct advantages for software teams. Finally, growth is detrimental to the effectiveness of the organization because it hinders the use of small-scale mechanisms and it leads to an undesirable formalization. The theory is supported with empirical evidence collected from five case studies of a wide variety of software organizations, and it has explanatory and predictive power. The thesis links this theory to other current research efforts and shows that it complements and enhances them by providing a more solid theoretical foundation and by reclaiming the relevance of synchronous, proximate, proportionate, and mature interactions in software organizations.
Iroquoian Infant Mortality and Juvenile Growth 1250 to 1700 AD
Keywords: growth
children
First Nations
Ontario
bioarchaeology
mortality
archaeology
infant
Iroquoian
health
burial

This thesis investigates changes in Iroquoian infant mortality and juvenile growth between 1250 and 1700 AD in the Lower Great Lakes region of North America. The objectives of this thesis are to investigate the tempo and quality of growth of Iroquoian infants and juveniles; to investigate the relationship between apparent neonatal and postneonatal mortality and predicted mortality ratios based on equal probability of mortality risk in the first year of life (1:11); and to investigate whether or not the ratio of neonatal to postneonatal mortality changed as a result of cultural change associated with the arrival of Europeans at around 1600 AD. These were investigated using a sample of infant and juvenile remains from twenty-one sites in upper New York state and Ontario. Tempo and quality of growth were examined by comparing femoral length at different ages to the Iroquoian adult femur length endpoint and to the growth patterns established in the Denver Growth Study and in other aboriginal North American archaeological samples. Above average infant growth is attributed to biocultural factors and infant mortality is largely caused by acute conditions. Below average juvenile growth, especially between two and seven years of age, is attributed to nutritional imbalances and overcrowding, poor sanitation, and infectious disease prevalence. Juveniles were likely chronically ill, resulting in poor attainment of stature, and this may have contributed to their deaths early in life. Apparent infant mortality was found to differ from predicted mortality, and this difference was attributed to cultural and environmental mortality biases that make interpretation difficult. Change in infant mortality ratios as a result of cultural change associated with European contact is evident in the Iroquoian context: the lack of neonatal remains in postcontact ossuaries is consistent with the ethnohistoric record, but the high proportion of neonates in precontact ossuaries suggests that observations made by ethnohistoric observers may not be applicable to our understanding of precontact burial patterns. The change in the ratio of neonatal to postneonatal remains in the pre- and postcontact periods is interpreted as evidence of changes in burial patterns rather than change in mortality risk.
Dynamical Foliations
Keywords: foliations
holomorphic dynamics
Henon maps
multidimensional complex analysis

This thesis is devoted to the study of foliations that come from dynamical systems. In the first part we study foliations of Stein manifolds locally given by vector fields. The leaves of such foliations are Riemann surfaces. We prove that for a generic foliation all leaves except for not more than a countable number are homeomorphic to disks, the rest are homeomorphic to cylinders. We also prove that a generic foliation is complex Kupka-Smale. In the second part of the thesis we study complex Hénon maps. The sets of points U+ and U − that have unbounded forward and backwards orbits correspondingly, is naturally endowed with holomorphic foliations [special characters omitted] and [special characters omitted]. We describe the critical locus – the set of tangencies between these foliations – for Hénon maps that are small perturbations of quadratic polynomials with disconnected Julia set.