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The cobordism ring: the perspective of characteristic classes
Get PDFThis written work, by Benedetta Andina, discusses ``The cobordism ring: the prospective of characteristic classes''. After providing sufficient preliminaries to make this thesis accessible to any graduate student, it clearly highlights how both the oriented and unoriented cobordism rings can be studied using characteristic classes, which are usually easily computable. To demonstrate this relationship in the unoriented case (as presented by Pontrjagin and Thom), the author unveils an explicit structure of the unoriented cobordism ring. This structure provides a clear classification of smooth closed manifolds
Are certain types of causes more feared than others? Exploring the role of feared causes, the feared self, and fear appeals in charitable giving.
Get PDFIndividuals engage in charitable giving for various reasons, such as due to the personal relevance of the cause (e.g., donating to the shelter one’s pet was adopted from), empathy toward the beneficiaries (e.g., victims of a natural disaster), and/or emotional (e.g., warm glow) or material (e.g., tax rebates) benefits, among many others. Although prior research has identified several determinants of charitable giving, gaps remain regarding why donors may contribute more money to certain charitable causes than others. The current research aims to address these gaps by examining the impact of fear as a determinant of charitable giving, and more specifically investigating whether 1) certain types of charitable causes are more (vs. less) feared than others due to 2) being more (vs. less) likely to evoke donors’ feared self, and 3) whether a cause’s inherent level of fear interacts with the use of fear (vs. neutral or hope) appeals in its marketing communications. Two pre-tests and four online experiments were conducted to test these hypotheses. The findings revealed that a more feared cause produced more favorable attitude and donation intentions compared to a less feared cause, by prompting higher levels of feared self (study 1). Further, fear (or neutral/hope) appeals did not reliably impact how donors responded to more (vs. less) feared causes (studies 2 and 3). Finally, theoretical, and managerial implications of the findings are discussed, as well as directions for future research
The Synthesis and Study of Inorganic Cu(I) Donor-Acceptor Dyads for Dye-sensitized Photocathodes
Get PDFThe dye-sensitized solar cell was first proposed by Grätzel and O'Regan in 1991. The idea behind this architecture was to use a dye to absorb visible light and then inject electrons into a wide bandgap semiconductor electrode, generating an electric current. The key component of the dye-sensitized solar cell was the dye molecule, inspired by the reaction center from natural photosynthesis in plants, which absorbs light and converts it into chemical energy. In recent years, this architecture has been adapted for synthesis where rather than generating a current, light-induced charge separation is used to transfer redox equivalents to a substrate initiating a chemical transformation. Devices driving these processes are known as dye-sensitized photoelectrochemical cells.
Previously, our group has shown that a copper(I)-based donor-chromophore-acceptor molecular system immobilized on a zinc oxide photoanode together with a copper(II)-based water oxidation catalyst can act as a light-harvesting photocatalytic assembly to split water. To enable the complementary reaction to reduce the protons formed from water splitting, we have designed a photocathode comprised of a copper(I)-based chromophore-acceptor dyad complex to drive a well-studied cobaloxime hydrogen evolving electrocatalyst with visible light. The molecular structures, optical properties and electrochemistry properties of the synthesized materials were characterized using techniques such as nuclear magnetic resonance spectroscopy, UV-Visible spectroscopy and cyclic voltammetry. In this thesis, the dye molecule dyad was installed on fluorine doped-tin oxide glass with a nickel oxide film and will work in concert with the previously studied photoanode to give a tandem cell where hydrogen gas as a solar fuel is expected to be produced effectively
The Progressive Imaginary: Platforms, Intellectuals, and Celebrities in Post-Crisis Argentina
Get PDFThe Progressive Imaginary: Platforms, Intellectuals, and Celebrities in Post-Crisis Argentina, examines the way that broadcast, digital platforms, media ownership, and national policy shaped the rise of media icons in Argentine popular culture in the aftermath of the 2001 economic crisis. This research focuses on how public personalities utilize contemporary broadcast television and digital video to contest the social and economic exclusions produced by neoliberal policies. Combining industrial and aesthetic analysis with geopolitical and historical contextualization, I examine the effects of media platforms in circulating figures who have been largely unexamined in both Northern and Southern academic circles. I anchor this project with key case studies—pop philosopher Darío Sztajnszrajber, feminist comedian Malena Pichot, and the serial biopics of Carlos Monzón, Carlos Tévez, Diego Maradona, and Eva Perón—that demonstrate the savvy use of state-owned and private media by emerging public figures who work to disseminate a progressive worldview, specifically focused on wealth redistribution, women’s rights, and anti-authoritarianism. I argue that Argentina—both its history and contemporary politics—has been thoroughly reimagined as a protector and expander of human rights through this strategic use of digital media platforms. I show, ultimately, how contemporary media global streaming platforms functions to exploit the progressive worldview as commodity export for both domestic and foreign audiences
Predicting Response to Stepped-Care Cognitive Behavioral Therapy for Insomnia (CBT-I) Using Pre-Treatment Heart Rate Variability (HRV) in Cancer Patients
Get PDFObjective: This longitudinal study examined whether high frequency heart-rate variability (HF-HRV) and HF-HRV reactivity to stress moderates response to cognitive behavioural therapy for insomnia (CBT-I) within a stepped-care framework in cancer patients with comorbid insomnia.
Methods: 177 participants (86.3% female; Mage=55.3, SD=10.4) were randomized to receive either stepped-care or standard CBT-I and were followed for 12 months following treatment. HRV measures were assessed at pre-treatment during a rest and worry period. Insomnia symptoms were assessed using the Insomnia Severity Index (ISI) and daily sleep diary across five timepoints.
Results: Resting HF-HRV significantly predicted pre-treatment sleep efficiency but not ISI score. No significant time x HF-HRV or CBT-I group x time x HF-HRV interactions were found, indicating that HF-HRV does not predict differential responses to the different CBT-I group. HRV reactivity was not cross-sectionally or longitudinally related to any outcome variables. In exploratory analyses, significant insomnia severity x time x HF-HRV interactions were observed, suggesting that HF-HRV may predict treatment responses differently based on initial insomnia severity.
Conclusion: Although resting HF-HRV was related to initial sleep efficiency, HF-HRV measures did not significantly predict response to either form of CBT-I. Resting HF-HRV may predict certain treatment outcomes when initial insomnia severity is considered, however these results are exploratory and of unclear clinical significance
Development of Deep Learning Techniques for Image Retrieval
Get PDFImages are used in many real-world applications, ranging from personal photo repositories to medical imaging systems. Image retrieval is a process in which the images in the database are first ranked in terms their similarities with respect to a query image, then a certain number of the images are retrieved from the ranked list that are most similar to the query image. The performance of an image retrieval algorithm is measured in terms of mean average precision. There are numerous applications of image retrieval. For example, face retrieval can help identify a person for security purposes, medical image retrieval can help doctors make more informed medical diagnoses, and commodity image retrieval can help customers find desired commodities. In recent years, image retrieval has gained more popularity in view of the emergence of large-capacity storage devices and the availability of low-cost image acquisition equipment. On the other hand, with the size and diversity of image databases continuously growing, the task of image retrieval has become increasingly more complex. Recent image retrieval techniques have focused on using deep learning techniques because of their exceptional feature extraction capability. However, deep image retrieval networks often employ very complex networks to achieve a desired performance, thus limiting their practicability in applications with limited storage and power capacity. The objective of this thesis is to design high-performance, low complexity deep networks for the task of image retrieval. This objective is achieved by developing three different low-complexity strategies for generating rich sets of discriminating features.
Spatial information contained in images is crucial for providing detailed information about the positioning and interrelation of various elements within an image and thus, it plays an important role in distinguishing different images. As a result, designing a network to extract features that characterize this spatial information within an image is beneficial for the task of image retrieval. In the light of the importance of spatial information, in our first strategy, we develop two deep convolutional neural networks capable of extracting features with a focus on the spatial information. For the design of the first network, multi-scale dilated convolution operations are used to extract spatial information, whereas in the design of the second network, fusion of feature maps obtained from different hierarchical levels are employed to extract spatial information.
Textural, structural, and edge information is very important for distinguishing images, and therefore, a network capable of extracting features characterizing this type of information about the images could be very useful for the task of image retrieval. Hence, in our second strategy, we develop a deep convolutional neural network that is guided to extract textural, structural, and edge information contained in an image. Since morphological operations process the texture and structure of the objects within an image based on their geometrical properties and edges are fundamental features of an image, we use morphological operations to guide the network in extracting textural and structural information, and a novel pooling operation for extracting the edge information in an image.
Most of the researchers in the area of image retrieval have focused on developing algorithms aimed at yielding good retrieval performance at low computational complexity by outputting a list of certain number of images ranked in a decreasing order of similarity with respect to the query image. However, there are other researchers who have adopted a course of improving the results of an already existing image retrieval algorithm through a process of a re-ranking technique. A re-ranking scheme for image retrieval accesses the list of the images retrieved by an image retrieval algorithm and re-ranks them so that the re-ranked list at the output the scheme has a mean average precision value higher than that of the originally retrieved list.
A re-ranking scheme is an overhead to the process of image retrieval, and therefore, its complexity should be as small as possible. Most of the re-ranking schemes in the literature aim to boost the retrieval performance at the expense of a very high computational complexity. Therefore, in our third strategy, we develop a computationally efficient re-ranking scheme for image retrieval, whose performance is superior to that of the existing re-ranking schemes. Since image hashing offers the dual benefits of computational efficiency and the ability to generate versatile image representation, we adopt it in the proposed re-ranking scheme.
Extensive experiments are performed, in this thesis, using benchmark datasets, to demonstrate the effectiveness of the proposed new strategies in designing low-complexity deep networks for image retrieval
All Work and No Play: How Digital Platforms Controlled Work, Disability, and Time During the COVID-19 Pandemic
Get PDFThis project aims to explore the complexities and pitfalls of the rapid shift to remote workspaces as a result of the COVID-19 pandemic, predominantly for disabled workers. This shift introduced a new way of working based on the use of mass collaboration platforms that aimed to keep us connected despite the limitations on gathering. With a focus on the stark change of the working environment between 2019-2022, I demonstrate how these platforms are the main channels for holding over older forms of workplace management. These outdated work practices end up deeply ingrained within the design of most mass collaboration tools. This fact both alters our relationship to time and space at work and allows for the exacerbation of discrimination to flow through the virtual workplace. The first chapter explores the former of the two, analyzing the histories of mass collaboration platforms and how they structure our navigation of time. I analyze both Zoom and monday.com to uncover how the crisis allowed many of their shortcomings to go unnoticed. In my second chapter I demonstrate how these virtual tools only further exacerbate ableism in the workplace, despite these spaces being virtual. I use Meta as a case study due to its novelty and incorporation of virtual reality in order to discuss accessibility and inclusion in the workplace. By analyzing these platforms I hope to uncover how these digital platforms can actually produce disability by creating inaccessible environments in the first place
Reconsidering the Canadian “Hinterland”: Visual Culture, the English-Wabigoon River, and the Mercury Collection of Marion Lamm 1945–1980
Get PDFThis thesis examines select visual culture produced and gathered in response to one of Canada’s worst environmental disasters: the mercury poisoning of the English-Wabigoon River in Northwestern Ontario. This catastrophic event is the contextual and historical point of entry to explore two related visual records first, the dominant settler-colonial place image produced by industry and government stakeholders; second, a more complex image world discernable in a locally gathered archive created by citizen archivist Marion Lamm (1918–1997). These representations and narratives are examined at the intersection of Anishinaabe and settler-colonial histories and contexts that formed around the mercury case. I employ discourse analysis located in late capitalist visual culture and archival histories to examine ephemera, periodicals, photographic publications, and a film within broader cultural and environmental histories surrounding the English-Wabigoon River. The primary questions guiding this thesis are: Who and what defines a Canadian hinterland? From what positions are its stories told? Here I trace how the dominant, settler-colonial place image of industrial success and a tourist paradise is complicated and challenged by a record of locally gathered materials. Through transtemporal readings of a catastrophic event, I identify gaps between the local and translocal tellings. In doing so, I hypothesize that the visual record produced and disseminated by government and industry stakeholders presents a settler-colonial “hinterland” visuality that was incoherent with local realities
Living Things: Feeling Into Art, Disability, and Embodied Presence
No full textFrom the 19th century German aesthetic theory of Einfühlung to contemporary scholarship in disability studies, many have noted the tendency to affectively and sensorially respond to visual art objects as fellow living, feeling beings. This phenomenon is complicated, however, both by variations in individual sensoriums and by cultural politics undergirding assumptions about what, how, and even if other people think and feel. Such assumptions become particularly evident in instances of art vandalism, where damaged art objects are often described in media coverage as injured beings needing care, while vandals are met with stigmatizing language related to mental illness and cognitive disability. Working against the assumption that art vandals – and, often, people with disabilities in general – are “senseless,” I explore how the creation, protection, destruction, and repair of art might all be approached as socially situated, intensely sensory, inescapably embodied, politically charged, and bound in threads of relation.
Structured as a lyric essay, this thesis interweaves aesthetic analysis and cultural criticism with personal experience of chronic illness and neurodiversity. Examining my own affective and sensory responses to art, artists, art vandals, and people I encounter, I consider what these reactions suggest about larger political networks of affect, care, and embodied relation. Creative writing, specifically the lyric essay’s “I” voice, provides a valuable methodology both to emphasize my own imbrication within this constellation of relationships and to call upon readers to consider their own.
As critics have noted, Einfühlung (literally “feeling in”) provides an intriguing critical framework but often fails to account for cognitive, sensory, and emotional differences between individuals, as well as for how social positionalities including race, class, gender, and sexual identity inform dynamics of feeling. Using an approach I term critical Einfühlung, I explore how such politics both shape and are shaped by encounters between art objects and human agents, including how my own living, feeling bodymind participates in these dynamics and bears their traces. Taking feelings seriously as a politicized intertwinement of affects and sensations arising out of relationship, I consider how feelings towards, with, and about aesthetic objects can illuminate social dynamics between people
Intersectional Discrimination and Psychological Distress Among Black 2SLGBTQIA+ People in Canada: A Critical Ecological and Systematic Review
No full textThe hegemonic power bestowed toward a biomedical psychiatric model of mental health aids in trivializing the impacts of the social context on managing risks and shaping the accessibility of resources. Bronfenbrenner’s (1979) ecological systems theory argues that the ecology of human development unfolds through interactions with different interdependent systems. The minority stress model suggests that exposure to discrimination in different ecological systems related to one’s “social statuses […] can result in adverse mental health outcomes” (Meyer, 2003; Schmitz et al., 2020, p.164-165). In this contemporary moment, while Black people are over-represented in care systems as already diseased prone, I wish to complicate this view by interrogating the colonial, multi-system, anti-Black, classist, sexist, homophobic, ableist, and transphobic roots of psychological distress experienced by Black 2LGBTQIA+ people. To this end, this thesis critically reviews Canadian literature examining Black 2LGBTQIA+ people’s multisystem experiences of distress and collective resistance strategies. It begins with a brief historicization unveiling the colonial roots of neoliberal understandings of mental health practice and exposing social work’s role in the settler-colonial project. Theoretical insights from decolonial and feminist approaches to social work and Mad Studies are deployed to problematize and create counter-narratives to neoliberal and biomedical models of mental health. Grounded in Black 2SLGBTQIA+ people’s collective embodied experiences and resistance strategies and the theoretical foundations mentioned above, this thesis provides recommendations for liberating marginalized people from oppressive mental health institutions at micro and macro levels of service provision