VictorJuiz/thesis huggingface dataset:
District Leaders as Members of a Professional Learning Community: Changing Approaches to Leasdership Practices
Keywords: supervisory officers
administrators
professional learning community
leadership practices
district change
school improvement

The term professional learning community is generally defined as a group of people sharing and critically interrogating their practice in an “ongoing, reflective, collaborative, inclusive, learning-oriented, growth-promoting way and operating as a collective enterprise” (Stoll, Bolam, McMahon, Wallace & Thomas, 2006, p. 223). The professional learning community is increasingly being used as an explicit change strategy for generating, sharing and managing knowledge in educational organizations. Improving the performance of a district requires district supervisory officers to build their capacity for learning how to improve leadership practices. In this retrospective qualitative study, I investigate to what extent leadership practices change for a group of district supervisory officers, that is, the senior leaders responsible for the district leadership functions, while they responded to provincial reform mandates between 2000 and 2006. I also examine whether this group of supervisory officers in one Ontario English Public School District, renamed Green Ridge District School Board (GRDSB) for anonymity, functions as a professional learning community. Data sources used in this investigation were developed through a university partnership between GRDSB and an Ontario Institute for Studies in Education field center known as the Midwestern Centre. Data were gathered from six research reports, written annually between 2001 and 2006; interviews from seven supervisory officers conducted in 2006; and interviews from 12 school administrator interviews held in 2005. One limitation of the study is that participants were selected from school sites that chose to become involved with the district change strategies and therefore tended to take a positive orientation when responding to semi-structured questions. The data gathered did not reflect the views of those who chose not to be actively involved in the district change strategies. This investigation’s findings inform leadership theory and practice with respect to the descriptions of evolving leadership practices of a group of supervisory officers as they worked to re-culture the GRDSB. Findings provide empirical support for the contention that a socially constructed environment, such as a professional learning community, provides a context for supporting changes to leadership practices through collective professional learning, problem solving, knowledge creation and knowledge sharing (Anderson, 2006; Honig, 2008; Louis, 2008).
Non-rigid Structure from Locally Rigid Motion
Keywords: computer vision
structure from motion

The non-rigid structure from motion problem typically involves recovering the 3D trajectories of a set of scene points, from their corresponding image trajectories. In this thesis, the assumption of locally-rigid motion is used to regularize this otherwise underconstrained problem. The key idea is that even when a scene undergoes complex global deformations, the trajectories of local triplets of scene points can often be approximated by the vertices of a rigidly moving triangle. This intuition informs our bottom-up reconstruction procedure, which discovers such triplets through a hypothesis and test framework. To this end, a rigid triangle model is fit to the proposed image trajectories and evaluated using a procedure that we call 3-SFM. The recovered triangle models are then integrated into a global solution, by resolving their orthographic depth ip and translation ambiguities. Lastly, we consider using this solution to initialize an energy based model, subject to a set of soft isometric constraints, in order to allow each observation to constrain the global scene structure. Results on several sequences, both our own and from related work, suggest that these models are applicable in diverse and challenging scenes, such as those including multiple deforming bodies.
The Mortality and Morbidity of Alcohol-attributable Injury
Keywords: Alcohol
Injury

Alcohol is a recognized cause of over 60 injuries and diseases and is consistently in the top 5 most important risk factors for global burden of disease. It is important to be able to measure how drinking alcohol affects our health, and how our risk of getting injured or acquiring diseases caused by alcohol is dependent on how much alcohol we drink. This type of information allows us to make personal choices about our health and is an integral piece of public health evidence to inform how alcohol policy is informed, implemented, or monitored. This analysis will, for the first time, model the effects of alcohol for injury outcomes over the entire drinking lifetime for men and women separately using a new method that aims to improve upon existing calculations by accounting for different patterns of drinking – both acute consumption and average daily drinking. In both cases, both the amount consumed and the number of times it is consumed is taken into account. Within acute consumption, the number of occasions and the amount ii consumed at each occasion was counted. What’s more, for the first time in this field, a lifetime approach was adopted – risks will no longer be seen as discrete, individual events that occur independently of each other. In this study, risks are combined much like other exposures to environmental substances or contaminants – in a cumulative manner over a lifetime of drinking. The method combines data sources from experimental data, from meta-analyses, Canadian mortality and hospital data, and survey data, making this a rich, yet complicated analysis. Its products were dose-response risk curves for each injury outcome, by sex, and age group, and alcohol-attributable fractions and their variance estimation for mortality and morbidity for injury. This study has important implications for forming and planning health policy, represents advancements in absolute risk calculation, and will result in important consumer-level information that will enable development of limits around healthy drinking.
Expertise and Policy Learning - The Case of the European Union's Research Policy
Keywords: policy learning
research policy

This thesis examines policy learning and expertise in the European Union research policy by focusing on the Open Method of Coordination (OMC) initiative. The research is guided by the overarching question - How do experts’ individual policy learning experiences relate to the EU’s research policy? First, background of the European Union’s research policy is presented, clarifying the need for policy learning. Second, the theoretical approaches on expertise and theories of policy learning are analyzed. The synthesis of the two streams of literature leads to a conceptual framework for the study, featuring two distinct perspectives of policy learning – the evidence-based approach and the value-based approach. This framework brings the individual experiences of the OMC participants into focus, allowing an examination of policy processes that do not always result in direct policy changes. For data collection three distinct OMC working groups are selected, each focusing on a different topic related to European research policy – research funding (Group 1), research cooperation with Third Countries (Group 2) and research activities in universities (Group 3). A case study approach is employed, involving document analysis, a pilot study and thirty-four interviews with member-states’ experts and European Commission policy-makers. The findings suggest that individual policy learning shapes the development of European research policy. Through the OMC policy learning initiatives participants gain new knowledge on policy approaches, programs, best practices and policy failures. In addition, learning experiences involve knowledge on individual relationships, decision-making styles, organizational cultures and power-relationships that diverse stakeholders bring with them to the process. Such knowledge helps to update the policy beliefs of participants, providing a strong foundation for developing mutual ownership of decisions that lead to policy coordination. The findings emphasize the importance of a value-based perspective in policy analysis, where results emerge gradually, over a long time period and contribute to policy change.
Chlamydia Trachomatis Disrupts Cytokinesis to Accelerate Nutrient Acquisition from Host Cells
Keywords: Chlamydia
cytokinesis

Chlamydia trachomatis is the leading cause of bacterial sexually transmitted infections worldwide and it has been linked to increased risks of cervical cancer. Our study aims to understand the mechanisms by which chlamydia infection contributes to higher risks of tumorigenesis. We discovered in over 90% of infected human epithelial cells that chlamydia inclusions localized to the host cell centre during mitosis and prevented the completion of cleavage furrow ingression. Infected cells that failed to divide into two daughter cells re-entered interphase as tetraploid multinuclear cells, which are known initiators of tumorigenesis. In order to address whether chlamydia actively sought the host cell centre during mitosis, we created vacuoles using internalized latex beads and our findings indicated that chlamydia inclusions localized to the host cell centre much more frequently than similarly sized vacuoles. In addition, we demonstrated that metabolically inactive chlamydia inclusions localized to the cell centre less frequently than inclusions under normal conditions. Together, these results suggested that chlamydia actively localized to the host cell centre to efficiently block host cell mitosis. We took advantage of the microtubule-displacing capability of the C. trachomatis inclusions and demonstrated that astral microtubules could promote furrow initiation independent of the central spindle microtubules. Microdomains on chlamydia inclusions play important roles in inclusion localization and chlamydia replication. We discovered that these structures were surprisingly resistant to bacterial protein synthesis and host Src family kinase inhibitors. Finally, we demonstrated that multinuclear cells that resulted from unsuccessful mitosis contained significantly higher Golgi content, an important nutrient source for chlamydia. Our results indicated that C. trachomatis in multinuclear cells intercepted Golgi-derived lipids faster than in mononuclear cells. Together, my results reveal that C. trachomatis inclusions robustly localize to the cell centre to block host cell mitosis in order to acquire host Golgi nutrients more quickly in multinucleated cells.
Heterogeneous Photochemistry of Atmospheric Dusts and Organic Films
Keywords: heterogeneous
photochemistry
mineral dust
urban pollutants

Little is currently known regarding the nature and consequences of interactions between photoactive surfaces, including mineral dust and ‘urban film’, and gas-phase pollutants in urban environments. In order to address this knowledge gap, this thesis explores the photochemical reactivity of these environmental surfaces in controlled laboratory settings. The photoenhanced ozonation of pyrene, a toxic product of incomplete combustion, proceeds at different rates and via different mechanisms at three model ‘urban film’ surfaces. These results are important because they suggest that the reactivity of a molecule on simplified surfaces may not accurately reflect its reactivity in the real environment. The photooxidation of isopropanol at the surface of TiO2, here used as a proxy for the photoactive component of mineral dust, yields gas-phase acetone. This chemistry is amplified by nitrate, a major surficial component of atmospherically processed dust. These results suggest that dust has the potential to convert non-absorbing species to photochemically active species, and thereby serve as a source of reactive organic radicals for further gas- or surface-phase chemistry. Oxalic acid, the most atmospherically abundant dicarboxylic acid, is efficiently oxidized to gas-phase CO2 at the surface of Mauritanian sand and Icelandic volcanic ash. These experiments indicate that the lifetime of oxalic acid may be limited in arid regions by Fe and Ti-catalyzed aerosol-phase photochemistry. Fluorotelomer alcohols (FTOHs), a class of industrial chemicals used in the production of surface coatings, undergo photooxidation at the surface of sand and ash to yield toxic and persistent perfluorinated carboxylic acids (PFCAs). These results provide the first evidence that the metal-catalyzed heterogeneous oxidation of FTOHs may act as a local source of aerosol-phase PFCAs. Illumination of Nigerien sand in the presence of gas-phase SO2 leads to the formation of surface-sorbed sulfate. This chemistry proceeds more efficiently on fine sand than on coarse sand. In chamber experiments, the illumination of SO2 in the presence of realistically produced dust aerosol results in new particle formation. Together, these results suggest that SO2 photochemistry at the dust surface has the potential to change not only dust hygroscopicity but also the net scattering potential of dust-containing air masses.
Secondary School Staffrooms as Perceived, Conceived, and Lived Spaces: An Investigation into their Importance, Decline, and Sublation
Keywords: staffrooms
Henri Lefebvre
teachers' labour
department workrooms
spatial theory
secondary schools

Secondary school staffrooms serve a genuine need for teachers not easily replaced by subject department workrooms, yet staffroom use in many schools has declined. As a result, some staffrooms are being turned into classrooms or even abolished altogether from secondary school designs. This dissertation investigates the causes and effects of the decline of secondary school staffroom use in a large Canadian school board. Henri Lefebvre’s spatial triad is applied to situate the investigation into spaces that are perceived, conceived, and lived. Staffrooms are analyzed as perceived spaces in the context of the production and reproduction of teachers’ labour, and the sub-communities of teaching found in workrooms. Staffrooms are viewed as conceived spaces by investigating their physical design and placement, as well as the role of secondary-level administrators in supporting or repurposing staffroom space. Staffrooms are understood as lived spaces by exploring how time, history, metaphor, and habit – especially habits formed in the early years of teaching – influence meaning for the users. Quantitative data drawn from a 23-question survey (256 responses) confirmed that although staffroom use had declined for the majority of respondents, secondary school staffrooms were still overwhelmingly considered to be necessary components of secondary schools even among non-users. The data analysis revealed that this decline was influenced by factors such as the isolated location of a staffroom, long distances from workrooms and classrooms to staffrooms, increased workloads, and habit. The findings of are supported by qualitative data in the form of 717 optional comments provided by survey participants, field notes from observing two secondary staffrooms: one inactive and the other frequently used, and through 26 semi-structured interviews held in five different staffrooms. It is my contention that staffrooms remain important to secondary school teachers as potential places for increasing perceptions of staff collegiality, providing opportunities for informal professional learning, developing cross-curricular connections, and managing teacher health and retention. The conclusion suggests how secondary school staffrooms might be reconfigured to better suit the needs of those who wish to use them.
Separable Spatio-spectral Patterns in EEG signals During Motor-imagery Tasks
Keywords: Signal Processing
Pattern Recognition
Brain-Computer Interface
Feature Extraction
electroencephalogram

Brain-Computer Interface (BCI) systems aim to provide a non-muscular channel for the brain to control external devices using electrical activities of the brain. These BCI systems can be used in various applications, such as controlling a wheelchair, neuroprosthesis, or speech synthesizer for disabled individuals, navigation in virtual environment, and assisting healthy individuals in performing highly demanding tasks. Motor-imagery BCI systems in particular are based on decoding imagination of motor tasks, e.g., to control the movement of a wheelchair or a mouse curser on the computer screen and move it to the right or left directions by imagining right/left hand movement. During the past decade, there has been a growing interest in utilization of electroencephalogram (EEG) signals for non-invasive motor-imagery BCI systems, due to their low cost, ease of use, and widespread availability. During motor-imagery tasks, multichannel EEG signals exhibit task-specific features in both spatial domain and spectral (or frequency) domain. This thesis studies the statistical characteristics of the multichannel EEG signals in these two domains and proposes a new approach for spatio-spectral feature extraction in motor-imagery BCI systems. This approach is based on the fact that due to the multichannel structure of the EEG data, its spatio-spectral features have a matrix-variate structure. This structure, which has been overlooked in the literate, can be exploited to design more efficient feature extraction methods for motor-imagery BCIs. Towards this end, this research work adopts a matrix-variate Gaussian model for the spatio-spectral features, which assumes a separable Kronecker product structure for the covariance of these features. This separable structure, together with the general properties of the Gaussian model, enables us to design new feature extraction schemes which can operate on the data in its inherent matrix-variate structure to reduce the computational cost of the BCI system while improving its performance. Throughout this thesis, the proposed matrix-variate model and its implications will be studied in various different feature extraction scenarios.
The Effects of ROS and DNA Repair on Methylmercury-initiated Neurodevelopmental Deficits
Keywords: Methylmercury
DNA Repair
Neurodevelopment
Reactive Oxygen Species

Methylmercury (MeHg) is an environmental toxin to which we are exposed through the consumption of seafood. Reactive oxygen species (ROS) have been implicated in the mechanism of toxicity, and in vitro studies in our laboratory have implicated DNA oxidation, particularly the DNA repair enzyme oxoguanine glycosylase 1 (OGG1). My studies determined the effects of in utero exposure to MeHg on fetal brain DNA oxidation and postnatal neurodevelopmental deficits, and the role of ROS-mediated oxidative DNA damage using the free radical spin trap, α-phenyl-N-tert-butylnitrone (PBN), and DNA repair-deficient ogg1 knockout mice. While neither MeHg nor PBN altered DNA oxidation in fetal brain, MeHg caused cognitive deficits in passive avoidance and novel object recognition, the latter of which was blocked by PBN pretreatment, suggesting ROS involvement. Preliminary longevity studies following one litter from each treatment group to 16 months suggest that in utero MeHg treatment may shorten lifespan. Endogenous DNA oxidation was increased in the brains of ogg1 knockout fetuses compared to wild-type littermates, although this was not enhanced by MeHg. However, OGG1-deficient animals exhibited cognitive deficits in passive avoidance after MeHg treatment, suggesting a role for DNA damage. Furthermore, ogg1 knockout female mice exhibited a passive avoidance deficit compared to wild-type females regardless of treatment, corroborating a role for oxidative DNA damage in neurodevelopmental deficits. MeHg increased apoptosis in the hippocampal region of fetal brain, and may cause DNA double-strand breaks (DSBs), evidenced by enhanced phosphorylation of histone 2AX (γH2AX). Ogg1 knockout progeny exhibited increased cellular proliferation or migration in the developing hippocampal region, which was blocked by MeHg. My results provide the first evidence that: (1) MeHg may decrease lifespan; (2) PBN protects against some postnatal neurodevelopmental deficits caused by in utero exposure to MeHg; and (3) DNA repair-deficient progeny are more susceptible to postnatal cognitive deficits caused by in utero MeHg exposure, suggesting that ROS-mediated DNA oxidation plays a role in MeHg-initiated neurodevelopmental deficits.
The Relationship between Exposure to Pornography, Victimization History, Attachment to Parents, and the Sexual Offence Characteristics of Adolescents who Sexually Offend
Keywords: pornography
sexual offenders
adolescent

This study was focused on exploring the relationship between victimization history, attachment to parents, pornography exposure/use, and characteristics of the sexual offences committed by male adolescents. It was hypothesized that, the poorer the attachment to parents, the greater number of abuses experienced, and the more exposure to pornography, the more likely an adolescent would be to have had more victims, have offended against more age groups, have both male and female victims, have committed penetration in his sexual offences, and have been forceful or violent in his sexual offences. The study involved secondary analysis of a large data set that was based on prior administration of an extensive survey which also included a number of psychological measures and questionnaires. A total of 308 male participants ranging in age from 13 to 20 at the time of completing the survey were included in this study. Participants were 12-17 years of age at the time of their sexual offending. A series of regressions were used to examine if attachment to parents, history of abuse/neglect, and pornography use could predict the number of victims, age group of victims, gender of victims, sexual intrusiveness, and level of force in the sexual offences that had been committed by the participants. Predictor variables that emerged as important in this study were the duration of the sexual offending, having experienced three or more types of abuse, and exposure to live sex. In general, it was suggested that treatment efforts should focus on intervening promptly and reducing the duration of an adolescent’s sexual offending and that intervention for all types of abuse be prioritized. Additionally, it was recommended that future research seek to identify characteristics that might predispose certain victimized individuals to develop sexual offending behaviours in the future. In general, it was noted that further explorations are needed regarding applicable theoretical approaches, as well as the various factors, and interactions among factors, that contribute to the characteristics of sexual offences committed by male adolescents.