UBIR Repository (Univ. at Buffalo)
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Modeled Patterns of Crevassing Induced by Supraglacial Lake Drainage in Western Greenland
No full textM.S.The Greenland Ice Sheet is expected to contribute substantially to global sea level rise over the next century in response to climate change. As increasing volumes of surface meltwater are delivered to the glacier bed via moulins during supraglacial lake drainage events, it has been hypothesized that new crevasses may form upflow, causing a cascade of lake drainages. This upflow expansion could alter ice sheet dynamics, leading to ice sheet instability and even greater sea level rise contributions. To investigate this hypothesis, we applied an analytical ice-flow model \cite{gudmundsson_analytical_2008} to calculate surface strain rates and infer the pattern of crevassing induced by a modeled rapidly drained lake. We calibrate the model using data collected during a lake drainage event in the summer of 2011 in the Pakitsoq region of Western Greenland. The patterns and extent of crevassing we see in our model results are highly dependent on the bed topography, basal sliding ratio, dimensions of the slipperiness patch, and the seasonal timing of the drainage event. Our model results show evidence of considerable crevassing occurring within 3--5.5~km upstream of the modeled lake drainage, with crevassing enhanced by a factor of 5--6 within a 3~km radius of the rapidly drained lake. Because lakes in this area are spaced by roughly 2--4~km, our results support the hypothesis for cascading lake drainage. This research improves our understanding of how meltwater may affect ice sheet dynamics, which are a major factor in how much the Greenland Ice Sheet will contribute to sea level rise in the future.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Selected Topics in Diagnostic Studies, Biomarker Evaluation and Beyond
No full textPh.D.In the simplest setting of diagnostic tests, the outcomes are dichotomous, either healthy or diseased. For many diseases such as Alzheimer's disease, there usually exist one or more intermediate stages between healthy and fully diseased stages. Therefore, accurate multi-category classification and biomarker evaluation under such settings are of paramount importance for biomedical and clinical research. This thesis mainly aims to develop novel and optimal classification methods as well as new biomarker combination methods in multi-class setting. These methods are expected to have broad applicability in practice. Several machine learning (ML) methods have gained their popularity in a variety of fields; however, little connection has been built and inspected between machine learning methods and statistical methods for biomarker evaluation. This thesis work also aims to fill such gap. Specifically, this thesis work consists of three parts: 1) to present several unexploited methods for cut-point selection which are strong competitors against existing ones; 2) to propose several biomarker combination methods which are more efficient and superior to the existing ones; and finally 3) to compare some popular machine learning methods with proposed biomarker combination methods in binary classification setting.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
English Education in China: Initiation, Evolution, and Impact - A Case Study of College English Test (CET-4/6) and College English Education
No full textPh.D.This dissertation investigates the impact of the CET-4/6 (College English Test Band Four/Six) on College English education at one university in China. It aims to explore the social contexts where CET-4/6 was initiated, used as a de facto language policy, and later dropped at this university, and investigate the impacts of CET-4/6 as a de facto language policy on College English teaching and learning. The research is guided by theories of the Macroacquisition of English (Brutt-Griffler, 2002, 2017) and test as de facto language policy (Shohamy, 2001). While the former provides an explanatory sociohistorical and policy framework to study the evolution and trends in English education in China, the latter offers an assessment perspective to reconsider the role CET-4/6 has been playing both in educational and social domains. This research uses a qualitative approach with multiple data collection methods. Using one university context as a case study, it analyzes data from questionnaire surveys, non-participant class observations, and interviews. Specifically, it studies the perspectives of College English Department faculty members, English training institute teachers, and non-English-major college students. To provide a broader context for the study, this research also incorporates data from interviews with national policymakers and university administrators, historical documents, media reports, and online resources. Data are analyzed through the constant-comparative method (Glaser, 1965), where themes, concepts, and patterns are identified (Braun & Clarke, 2006). The findings indicate that the initiation of CET-4/6, the use of CET-4/6 as a de facto language policy, and the drop of this policy are aligned with the general trend in English education in China. The impact of the change of policy on College English education is limited, and CET-4/6 has become a default option for college students and a part of college life. English learning has evolved from a government campaign into a conscious act taken by individuals to achieve specific goals, during which mutual influence within distinct speech communities is playing out and exerts an ever more significant role. This study draws a comprehensive picture of the history of CET-4/6 and English education in China. The findings could be used by policymakers, university administrators, English educators, and English learners to use as a reference to make College English education more efficient, and to address challenges that College English education is facing in the 21st century.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Curricular Reform: The Role of Collaboration as it Relates to Professional Development
No full textEd.D.This study will add to a growing body of literature on collaboration by examining how teachers perceive and react to various forms of collaboration, such as PLCs, as they relate to curricular changes brought on by a reform initiative. The purpose of this study was to examine the ways that collaboration during professional development shaped a teacher's personal sense of success when adapting to meet changes brought forth from curricular reform. This study was designed as a representative multi-case study with one unit of analysis. Twenty middle school teachers from Western New York were selected based on Math and English certifications from three different sites. Utilizing semi-structured interviews and document analysis, the following conclusions emerged:1.) Teachers critically value the resource of time when considering their own perception of how productive a collaboration was. 2.) The physiological and affective domain of self-efficacy had an especially strong impact on the ability of a teacher to effectively collaborate in a group setting. 3.) Teachers often perceived success from a collaboration through the lens of tangible products, such as lesson, worksheets, or units and whether or not those products brought about higher levels of student engagement in the classroom.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
'You Got Five Minutes to Be Upset, Then You Gotta Be a Gangsta': A Qualitative Understanding of the Strong Black Woman Phenomenon Through the Lens of African American Acculturation
No full textPh.D.Since the introduction of the Strong Black Woman (SBW) as a psychological construct, numerous researchers have provided literature and contributory articles. However, few researchers have incorporated the concept of acculturation. Understanding acculturation is important when considering the phenomenological experience of Black women, because the SBW is a cultural construct predicated on race and gender. This study is among the first to explore the SBW phenomenon through the lens of African American acculturation. Participants were also asked to reflect on their experiences of the current sociopolitical climate as well. This phenomenological qualitative study employed the use of Critical Race Theory and Black Feminist Thought for development of semi-structured interview questions and continued to draw on CRT and BFT for thematic data analysis. The research questions pertained to the phenomenological experience of African American women, with the intention of exploring the Strong Black Woman phenomenon through the lens of African American acculturation. A total of 10 self-identified Black/African American women were interviewed. Qualitative phenomenological methodology and analysis revealed six themes: (1) Pride, (2) Intersectionality and Oppression, (3) Expectations, (4) Trauma, (5) Adverse Health Effects, and (6) Coping and Psychological Flexibility; with several related subthemes. These themes highlighted the nuanced nature of the Strong Black Woman Phenomenon and the related cultural context, whereas the acculturative experiences of Black women provide information about the cultural messages Black women have received. The results of this study add to the current paucity of research involving the Strong Black Women phenomenon and acculturation.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
In Case of Emergency: Science Fiction and Survival in the Age of Climate Change
No full textPh.D.This project examines the question of survival in science fiction, with particular emphasis on the genre's engagement with the ongoing global climate crisis. The author argues that, beginning with the early origins of the genre in the nineteenth century, works of science fiction have often engaged with the science of climate change, and practical matters of survival, with greater imagination – and, frequently, more useful insight – than thinkers and policy makers in the sciences and politics. In supporting these arguments, the author examines works of fiction by Mary Shelley, Margaret Atwood, and Octavia Butler; and engages with the theoretical and historical work of Franco Moretti, Clare Colebrook, Manuel DeLanda, Gillen D'Arcy Wood, and William and Nicholas Klingaman.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Dialogue Within the Context of a Read-Aloud Event: Literacy and Oracy Practices in One Pre-K Community
No full textPh.D.This qualitative case study examined the speaking, listening, and reading practices associated with read-alouds (RALs) in a Pre-K classroom during eight weeks of the Fall 2016 semester. The observed Pre-K classroom was part of the Happy School, a play-based research center affiliated with a local university situated in a sub-urban section of a rust-belt city in the United States. The Pre-K teacher and 10 of her students were the focal participants of this study. In order to understand my case in its totality and paint a comprehensive picture, the data collection in this research involved the following qualitative data sources: 1) video recordings; 2) researcher-generated documents such as fieldnotes and analytic memos; 3) semi-structured formal and informal teacher interviews; 4) teacher-generated artifacts such as digital copies of the lesson plans; 5) pictures of the classroom environment; and 6) pictures of student-generated artifacts such as student writing, painting, art, and crafts. Sociocultural discourse analysis and descriptive statistics were employed to analyze the collected data (Mercer, 2004, 2008). This allowed for RAL data analysis at both macro and micro levels; that is, across and within the RALs. The findings suggest that a repertoire of RALs was utilized to form curriculum coherence, which was further supported by the teacher’s planfulness and responsiveness to the classroom dynamics. The findings also demonstrate the presence of dialogically orchestrated RAL talk that was used to maintain curriculum coherence and enhance students’ understandings of school content. This study fills a gap in scholarship pertaining to RALs and dialogic pedagogy by (1) articulating how a RAL event was planned and enacted in a Pre-K classroom over time and (2) highlighting the patterns of naturally occurring talk that were utilized to create curriculum coherence within and across the RAL sessions.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Explore Nano-Solenoids Using Two Dimensional Materials
No full textM.S.Recent advances in nano-structures and two dimensional (2D) materials especially with graphene led to the idea for the project. The aim of this project is to investigate electromagnetic properties of 2D graphene and other layered materials for nano-scale solenoid application. This project is an important step towards being able to understand how the material works and gives us key information regarding their electromagnetic properties and will help us create devices that are light-weight and electromagnetic in nature. In this thesis the idea for creating a nano-solenoid is explained. Graphene was chosen for this purpose due to its excellent electrical conductivity, however after simulation work it was seen that graphene is not the most ideal material for the device. The other suitable candidates that stood out were graphene hybrids and 2D ferromagnetic materials. ANSYS platform was used to simulate all the results and a number of problems arose while using graphene in this simulation work, one of them being the low B-H curve of the material. The important characteristics that show the magnetic behavior of a material is explained in this paper. To mitigate this problem, it was more viable to create a nano-transducer using graphene and other 2D magnetic materials. ANSYS was helpful in understanding the required characteristics of nano-devices, but the limitations of the software is also discussed. The performance of the device in simulation has led us to believe that such a device can be realized in the lab, and the importance of chemical vapor deposition (CVD) and other methods of obtaining flakes have also been discussed in detail.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Enantioselective Synthesis of Five-Membered Cyclic Ethers via Copper(II)-Catalyzed Carboetherification and Hydroetherification of Alkenes
No full textPh.D.In this dissertation, the enantioselective copper-catalyzed carbotherification and hydroetherification of unactivated alkenes is discussed. These methods offer a competitive approach for enantioenriched five-membered cyclic ether synthesis. Cyclic ethers have demonstrated broad utility from fuel additives to moieties of bioactive small molecules. This dissertation is divided into two chapters. Chapter one describes the development of enantioselective copper catalyzed carboetherification reactions and its application of enantioenriched phthalan compounds and (R)-fluspidine synthesis. (R)-fluspidine is a σ1 receptor ligand, which can bind to the σ1 receptors of brain cell in human body, is a potential drug for the treatment of Alzheimer’s diseases. Chapter two describes the development of enantioselective copper-catalyzed hydroetherification of alkenes and its application to the synthesis of enantioenriched five-membered cyclic ethers and (R)-furametpyr. (R)-furametpyr is a fungicide, which can be used to control the disease of the rice.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Developing Embedded Assessments for Game-Based Learning in a Road Vehicle Dynamics Course
No full textM.S.As educational tools continue to utilize evolving technologies, game-based learning has come to the forefront of novel educational practices for its ability to improve specific educational outcomes such as motivation, engagement, and knowledge acquisition. Current research has focused on utilizing self-report surveys and knowledge assessments to identify educational outcomes as a result of game-based learning. While this has alluded to the propensity for positive effects of game-based learning, there is a scarcity of research that elucidates learning outcomes with in-game data. This paper attempts to build upon previous research of utilizing in-game data to track students' learning outcomes with two separate pilot studies comprised of senior-level engineering students in the Road Vehicle Dynamics course at the University at Buffalo. Both pilot studies utilize a high-fidelity simulator to deploy a vehicle simulation game. The first pilot study is based upon the students' ability to achieve neutral steer where a learning rate is derived from the real-time data gathered from the simulator. The second pilot study is a comparison of the learning outcomes of two separate versions of a game that develops students' cornering skills; the Gauge version is characterized by the in-game scaffolding it provides, while the Ghost version is characterized by its emphasis on competition.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*