Thesis (Ph. D.)--Florida State University, 2003. / Advisor: Dr. David H. Van Winkle, Florida State University, College of Arts and Sciences, Department of Physics. Title and description from dissertation home page (viewed Oct. 1, 2003). Includes bibliographical references.

Thesis (Ph. D.)--University of Chicago, Department of Astronomy and Astrophysics, August 2003. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

Glaucoma is a common disease that is difficult to diagnosis early using only visual field tests. Current research indicates that determination of retinal nerve fiber layer thickness (RNFLT) can serve as an early indicator of glaucoma [1]. RNFLT is measured by segmenting non-invasive optical coherence tomography images. However, high speckle noise and presence of artifacts in the images cause traditional layer detection and segmentation methods to fail. Multiphase active contours segmentation methods utilize region intensity and shape terms to produce multiple continuous boundaries simultaneously in noisy environments. A 2D and 3D multiphase active contours based algorithm was created to segment synthetic and real human retina OCT images. The 2D multiphase algorithm segmented eight simultaneous layers with a 3.14% mean A-scan error rate per layer. The 3D approach performed qualitatively accurate segmentation of a 20 image stack simultaneously. In an artificial, high-noise image stack the incorporation of more pixels per layer allowed improved segmentation using the 3D algorithm over the 2D. These results indicate that 2D and 3D multiphase active contours algorithms can be used to accurately segment retina layers. With further development to reduce computation time and automate initialization, these algorithms could be used to provide close to real-time clinical retinal image segmentation. / text

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published_or_final_version / Physics / Master / Master of Philosophy

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Through a descriptive case study methodology, this thesis describes the possible impact of an inquiry curriculum on four low-achieving students' causal attributions. Inclass observations, retrospective interviews and questionnaires were used to examine the possible effects of this instructional approach on the students' causal thinking patterns. Inquiry was found to have a possible influence on three of the four students' causal attributions. These three student's causal attributions shifted from a maladaptive pattern to a more adaptive pattern while using an inquiry curriculum. Inquiry was believed to be linked to the changes found in three of the students insofar as effort and control are integral parts of an inquiry curriculum. The fourth student's attributional pattern was largely unaffected by the inquiry curriculum. The results are further interpreted in light of the instructional context and the teacher's influence and control over the inquiry process.

Curriculum reform emphasizes the importance of inquiry instruction for learners. For inquiry-oriented curriculum to occur, attention must be focused on teacher education. Using a mixed-methods design, I investigated if and how groups of student teachers who receive different types of exposure to inquiry differ in their understanding of inquiry instruction. Preservice teachers' descriptions of inquiry experiences in their teacher-preparation program contextualized the results. Considerable effort was given in the first phase of this study to establish the reliability and validity of the Strategic Demands of Inquiry questionnaire. / Participants were from McGill University, Montreal, and included preservice teachers in the Bachelor of Education program, Continuing Education students enrolled in an inquiry-based course, and Honours Psychology students engaged in research. Data sources included the Strategic Demands of Inquiry questionnaire and an interview schedule. / Groups who had different types of exposure to the inquiry approach varied in how they understand inquiry instruction. Fourth-year Elementary preservice teachers held more sophisticated conceptualizations of the inquiry approach and greater appreciation for the components involved in carrying out an inquiry curriculum compared to first-year Elementary preservice teachers. After the completion of an inquiry-oriented course, Continuing Education students (including experienced teachers) were similar to fourth-year Elementary student teachers in conceptualizing and identifying important components of inquiry instruction. First-year Elementary and Secondary student teachers were different in their views of inquiry instruction. Finally, Honours Psychology students, who were engaged in scholarly research, held sophisticated conceptualizations of the inquiry approach. However, they did not use this knowledge of the inquiry method as extensively as fourth-year preservice teachers to identify important aspects of inquiry instruction. Therefore, although experience with the inquiry method may be necessary for conceptualizing inquiry as a pedagogical approach, it is not sufficient to enable undergraduates to identify important aspects of planning, enacting, and evaluating an inquiry curriculum. / These findings point to the importance of the Bachelor of Education program in advancing knowledge about inquiry instruction. Fourth-year student teachers reported experiences with the inquiry approach that influenced their understanding of this method. This study also provided evidence for the construct validity of the Strategic Demands of Inquiry questionnaire.