Biomaterial interactions with compromised tissue surfaces

This thesis is concerned with the nature of biomaterial interactions with compromised host tissue sites. Both ocular and dermal tissues can be wounded, following injury, disease or surgery, and consequently require the use of a biomaterial. Clear analogies exist between the cornea/tear film/contact lens and the dermal wound bed/wound fluid/skin adhesive wound dressing. The work described in this thesis builds upon established biochemistry to examine specific aspects of the interaction of biomaterials with compromised ocular and dermal tissue sites, with a particular focus on the role of vitronectin. Vitronectin is a prominent cell adhesion glycoprotein present in both tear fluid and wound fluid, and has a role in the regulation and upregulation of plasmin. The interaction of contact lenses with the cornea was assessed by a novel on-lens cell-based vitronectin assay technique. Vitronectin mapping showed that vitronectin-mediated cell adhesion to contact lens surfaces was due to the contact lens-corneal mechanical interaction rather than deposition out of the tear film. This deposition is associated predominantly with the peripheral region of the posterior contact lens surface. The locus of vitronectin deposition on the contact lens surface, which is affected by material modulus, is potentially an important factor in the generation of plasmin in the posterior tear film. Use of the vitronectin mapping technique on ex vivo bandage contact lenses revealed greater vitronectin-mediated cell adhesion to the contact lens surfaces in comparison to lenses worn in the healthy eye. The results suggest that vitronectin is more readily deposited from the impaired corneal tissue bed than the intact healthy tissue bed. Significantly, subjects with a deficient tear film were found to deposit high vitronectin-mediated cell adhesion levels to the BCL surface, thus highlighting the influence of the contact lens-tissue interaction upon deposition. Biomimetic principles imply that adhesive materials for wound applications, including hydrogels and hydrocolloids, should closely match the surface energy parameters of skin. The surface properties of hydrocolloid adhesives were found to be easily modified by contact with siliconised plastic release liners. In contrast, paper release liners did not significantly affect the adhesive surface properties. In order to characterise such materials in the actual wound environment, which is an extremely challenging task, preliminary considerations for the design of an artificial wound fluid model from an animal serum base were addressed

The nature and consequence of vitronectin interaction in the non-compromised contact lens wearing eye

Purpose: The aim of this work was to investigate the locus and extent of vitronectin (Vn) deposition on ex vivo contact lenses and to determine the influence of wear modality together with surface and bulk characteristics of the lens material. Methods: The quantity and location of Vn deposition on the surfaces of contact lens materials was investigated using a novel on-lens cell attachment assay technique. Results: Vn mapping showed that deposition resulted from lens-corneal interaction rather than solely from the tear film. Higher cell counts on the posterior surface of the lenses were determined in comparison to the anterior surface. Overall gross Vn deposition was greater for high water content-low modulus materials (117. ±. 4 average cell count per field) than low water content-high modulus materials (88. ±. 6 average cell count per field). Conclusions: The role of Vn in plasmin regulation and upregulation is widely recognised. The findings in this paper suggest that the locus of Vn on the contact lens surface, which is affected by material properties such as modulus, is potentially an important factor in the generation of plasmin in the posterior tear film. Consequently, the potential for materials to affect Vn deposition will influence lens-induced inflammatory processes

Assessing Teacher Dispositions In Pre-Service Teachers

The purpose of this study was to determine whether there was a significant difference between the perceived dispositions in pre-service teachers in urban settings versus non-urban settings. It was also the intent of this study to describe the change in perceived dispositions throughout pre-service teachers’ internship experiences. Graduate students (N=44) from a teacher education program participated by providing responses to surveys, reflections, and focus groups. Final Assessment (FA) grades were also gathered to validate responses. The nature of self-reported data requires this study to collect both quantitative and qualitative data so that pre-service teachers’ responses can be validated with their experience, which influenced the decision to employ a mixed-methods design for this study. A triangulation mixed methods design (QUANT + QUAL) was used. The quantitative analysis used a non-experimental comparative approach. Inductive within deductive coding was used to analyze the journal responses and focus groups. Template analysis (King, 2004) used pre-established codes based on the 10 INTASC Principles and Dispositions Indicators (1992). Themes also emerged inductively and were identified throughout the coding process

Improving Teacher Quality for Colorado Science Teachers in High Need Schools

This article describes the evaluation of an online professional development program funded by the State of Colorado to address the need for highly qualified science teachers in high need and/or rural school districts. Recruitment and the retention of highly qualified educators in high need and/or rural school districts is a critical factor affecting the education and the possible career trajectory of students enrolled in science, technology, engineering and math (STEM) related courses. The program describes the participants experiences with the online format, the educational courses offered, and the overall effect of the program. The results of the evaluation provided positive results for participants experience and valuable information regarding improvements to such programs

Teacher Work Sample Methodology: Displaying Accountability Of U.S. Teacher Education Program Effectiveness

Productive strategies for evaluating outcomes in teacher licensure programs are becoming increasingly important in the education field. Research data from 492 teacher licensure program completers from 2006-2009 in the School of Education, Colorado State University, Fort Collins, Colorado (USA) was compiled after accreditation by the Colorado Department of Higher Education (CDHE) and the Teacher Education Accreditation Council (TEAC). Three categories including subject matter knowledge, pedagogy, and caring teaching skills were acknowledged in accreditation. An important pedagogy experience for students during the licensure program was teacher work sample methodology. This article discusses teacher work sample methodology, explains the experience of building a teacher work sample (TWS) and presents data regarding students’ results from TWS rubrics. Findings demonstrate teacher education program effectiveness and highlight the effective use of TWSs to meet accreditation requirements

The Rise and Decline of Jefferson, Texas

This thesis examines the history of Jefferson, Marion County, Texas, and its cycle of prosperity and decline

Researching enquiry-based blended learning in social work education

Enquiry-based blended learning (EBBL) research in social work education forms the basis of this submission. The core EBBL theme is defined, developed and analysed through four avenues of research, namely, scenario-planning, teaching and learning using EBBL, researching students’ experiences of EBBL and embedding EBBL practices in interdisciplinary higher education. One software publication is submitted illustrating how the author’s ability to work at the intersection of social work practice experience, learning design innovation and digital technology development has enabled him to present a unique perspective in this area of research. Two written and two software publications set the context for the scenario-planning themes that have influenced the EBBL research. Four themed written publications explore the development of teaching and learning approaches using EBBL, and lessons from students’ experiences of engaging with these EBBL designs. Two written publications explore the barriers and enablers to embedding EBBL practices in interdisciplinary higher education. Using enquiry, a mixture of face-to-face and online teaching methods, life-like learning scenarios and opportunities to engage in independent and group-based learning, the research illustrates that EBBL approaches can help educators to enable learners to meet and, where possible, exceed the requirements of pre-qualifying social work education

Earth Observation GroundSystems in the Cloud

DEFINITION: A pooled set of compute resources that can be centrally managed and dynamically provisioned to provide the required computation power or storage for a specific task WHY USE IT: Enhanced compute resource management High data-rate applications requiring pooled compute resources Remote ground terminals that cannot support processing at the antenn