The structure and performance of collagen biomaterials : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Engineering, Massey University, Palmerston North, New Zealand

Type I collagen materials are used in a wide range of industrial applications. Some examples include leather for shoes and upholstery, acellular dermal matrix (ADM) materials for surgical applications, and bovine pericardium for the fabrication of heart valve replacements. The structure of these materials is based on a matrix of collagen fibrils, largely responsible for the physical properties and strength of the materials. How the collagen fibrils themselves contribute to the overall bulk properties of these materials is not fully understood. The first part of this work investigates a collagen structure defect in leather, known as looseness. Looseness occurs in around 5-10% of bovine leather, and is a result of the collagen fibril layers separating during processing from raw skin to leather. A greater understanding of why looseness develops in leather and a method of detecting looseness early in processing is needed to save tanners a significant amount on wasted processing time and costs. In addition, an environmentally safe method of disposing of defect and waste leather is sort after since the current method of disposing to landfill is causing environmental concern due to the possibility of chromium leaching from leather into the soil as it biodegrades. Synchrotron based small angle X-ray scattering (SAXS) revealed that loose leather has a more aligned and layered collagen fibril arrangement, meaning there is less fibril overlap, particularly in the grain-corium boundary region. This results in larger gaps in the internal structure of loose leather compared with tight. These gaps could be detected using ultrasonic imaging in partially processed pickle and wet-blue hides as well as leather. Incorporating an ultrasound system into the leather processing line could be a viable method for identifying hides deemed to develop looseness earlier in processing, and these could be diverted down a separate processing line or removed. Disposing of waste leather by first forming biochar prior to land fill proved to be an effective way of reducing chromium from leaching into the environment. XAS revealed that heating leather to temperatures above 600°C in the absence of oxygen formed a char where chromium was bound in the stable form of chromium carbide. The stability of this structure makes chromium less available to form the toxic hexavalent form in the environment and presents a possible alternative option for environmentally safe disposal of leather. The second part to this work looks at the correlation between collagen fibril structure in a range of biomaterials in relation to material strength. Leather, ADM and pericardium are three type I collagen based materials which rely on sufficient strength to carry out their industrial and medical applications. These three materials were studied to try and identify collagen fibril characteristics that relate to high material strength. SAXS on a range of leather samples from various species revealed that collagen fibril diameter had only a small influence over material strength in bovine leather, and no correlation to strength in leather from other species. Therefore it can be said that the influence of fibril orientation on leather strength takes precedence over that of fibril diameter. Fibril diameter, d-spacing and orientation were studied in pericardium using SAXS while simultaneously applying strain. It was revealed collagen materials undergo two distinct stages of deformation when strain is applied and incrementally increased. The first stage, at low strain, involves a re-orientation of fibrils to become more aligned. When strain is increased further, the fibrils themselves take up the strain, causing fibrils to stretch and decrease in diameter. The Poisson ratio of the collagen fibrils was calculated to be 2.1 ± 0.7. This high Poisson's ratio indicates the fibrils decrease in diameter at a faster rate than they elongate with strain, and as a result the volume of the fibrils decreases. This feature of collagen could help explain some of the unique behaviours and strength of collagen based materials and could be useful for optimizing industrial applications of collagen materials. ADM materials, derived from human, porcine and bovine skin was the third collagen material studied. SAXS revealed that each species of ADM material had a slightly different collagen fibril arrangement when viewing the samples perpendicular to the surface. Human ADM was highly isotropic in arrangement, porcine was largely anisotropic, and bovine was somewhere in between the two. Bovine has a more layered fibril arrangement edge on and was the strongest material, followed by human ADM, and porcine was significantly weaker. Bovine was also the most porous material of the three. The discovery of the variations in strength, porosity and fibril arrangement between the three types of ADM materials may help medical professionals select the most suitable material for specific surgical procedures and could lead to a greater number of successful surgeries taking place

Family Literacy and Engagement: A Framework

The purpose of this project was to construct a framework for a family literacy program that would inform parents of Native English Speakers and English Learners on literacy practices and allow time for families to practice literacy together. The family literacy program consists of three sessions, each comprised of a 20-minute presentation to parents and a 30-minute parent-child literacy activity. Each session covered a different topic: early literacy practices, technology and literacy, and advocating for student success. The program was implemented in an adult literacy center, where parents who attended classes at the center and parents in the surrounding community could bring their families to participate in the program

Further characterisation of the envelope stress responses of Salmonella Typhimurium

Salmonella serovars are enteric pathogens of economic and clinical importance. The ability of Salmonella spp. to sense and adapt to exogenous stresses contributes towards infection severity and prevalence. The envelope stress responses promote survival within and between hosts by maintaining envelope homeostasis and promoting the rapid response to environmental insults. In this study, we present the first comprehensive analysis of the Cpx regulated transcriptome in S. Typhimurium, identifying 116 genes as novel members of the S. Typhimurium Cpx regulon. Transcriptomic analyses, EMSAs and mutant screens further establish CpxAR as a major contributor to S. Typhimurium virulence through regulation of SPI-1, and as a regulator of post-transcriptional modification through the positive and negative regulation of small regulatory RNAs (invR, omrA and omrB). Our data confirm Cpx contribution to copper tolerance, a positive regulator of the heat shock sigma factor rpoH and adds polyamine homeostasis and regulation of host cell apoptosis to the growing list of Cpx regulated processes. Furthermore, we present the first transcriptomic investigation into the ZraSR two-component signal transduction system and characterisation of its accessory protein, ZraP. We suggest ZraR mediated positive regulation of the virulence factors MntH and GroEL, GroSL, DnaK and ClpB (the heat shock chaperones). In addition, we show critical requirement of ZraSR for maximal carbon-starvation induced cross-resistance to heat and polymyxin B. The ZraR regulon described here includes functional groups required to promote survival within the Salmonella containing vacuole and genes contributing towards anaerobic metabolism. This work provides the foundations for investigating the contribution of ZraSR to Salmonella hostpathogen interactions and the potential this newly characterised ESR has as a target for investigating Salmonella survival within host cells. Together these investigations highlight the potential ESRs could hold as critical contributors to Salmonella pathogenicity and as therapeutic targets for the treatment of Salmonella infections

Understanding Female Veterans’ Perceived Social Support as Influenced by Higher Ground Military Program

Female servicemembers are quickly growing as the largest minority within the military, yet female veterans are not often represented widely in the literature (Hawkins & Crowe, 2018a, 2018b; Lundberg et al., 2016). Numerous studies have indicated that female-specific needs are not being met by healthcare agencies and services need to change to fill that void (Hawkins & Crowe, 2018a, 2018b). As such, researchers should conduct studies in order to help develop best-practices regarding the provision of services for this population. This research project was developed to help fill the gap in in the literature regarding the various lived experiences of female veterans with recreational therapy programming post-deployment. Additionally, there is a lack of readily available research indicating how practitioners can facilitate social support for female veterans, another purpose for this study. This study is part of a larger multi methods study with a combination of semi-structured interviews and a survey provided to female veterans who are past participants of Higher Ground’s military program (HGMP) in order to investigate how participating in HGMP impacted their perceived social support. This paper will report only the quantitative portion regarding how participating in Higher Ground’s military program impacts the perception of social support that female veterans experience post-deployment. The results indicate that participants experienced an increase in post-deployment support and improvement in family experiences. While it was outside the scope of this project to investigate exactly which aspects of programming potentially impacted the perception of social support, it will explore programmatic aspects so practitioners may consider adding them. Further research should look further into these programmatic aspects so practitioners have a guide for facilitating social support

Koch Industries, Inc. Strategie Corporate Research Report

[Excerpt] With its 2005 purchase of paper giant Georgia-Pacific, Koch Industries became the largest privately-held corporation in North America. Originally started as an oil production and refining firm in the first half of the twentieth century, Koch now has major operations in petroleum, chemicals, energy, fibers and polymers, minerals, fertilizers, chemical technology equipment, forest and consumer products, ranching, trading, and securities and finance. The company, based in Wichita, Kansas, employs 80,000 people in sixty countries worldwide. Koch’s oil operations are run primarily through the Flint Hills Resources family of subsidiaries, which has a production capacity of about 800,000 barrels of crude oil daily. Another one of Koch’s major ventures, synthetic textiles, operates through the company’s wholly-owned subsidiary, INVISTA, which produces both consumer and commodity textiles. Koch’s newest project, forest and consumer products, operates through Georgia-Pacific, which remains an independent but wholly-owned subsidiary of Koch Industries

Barriers and facilitators to the implementation of the advanced nurse practitioner role in primary care settings: a scoping review

Background: Workload and workforce issues in primary care are key drivers for the growing international trend to expand nursing roles. Advanced nurse practitioners are increasingly being appointed to take on activities and roles traditionally carried out by doctors. Successful implementation of any new role within multidisciplinary teams is complex and time-consuming, therefore it is important to understand the factors that may hinder or support implementation of the advanced nurse practitioner role in primary care settings. Objectives: To identify, appraise and synthesise the barriers and facilitators that impact implementation of advanced practitioner roles in primary care settings. Methods: A scoping review conducted using the Arksey and O’Malley (2005) framework and reported in accordance with PRISMA-ScR. Eight databases (Cochrane Library, Health Business Elite, Kings Fund Library, HMIC, Medline, CINAHL, SCOPUS and Web of Science) were searched to identify studies published in English between 2002 and 2017. Study selection and methodological assessment were conducted by two independent reviewers. A pre-piloted extraction form was used to extract the following data: study characteristics, context, participants and information describing the advanced nurse practitioner role. Deductive coding for barriers and facilitators was undertaken using a modified Yorkshire Contributory Framework. We used inductive coding for barriers or facilitators that could not be classified using pre-defined codes. Disagreements were addressed through discussion. Descriptive data was tabulated within evidence tables, and key findings for barriers and facilitators were brought together within a narrative synthesis based on the volume of evidence. Findings: Systematic searching identified 5976 potential records, 2852 abstracts were screened, and 122 full texts were retrieved. Fifty-four studies (reported across 76 publications) met the selection criteria. Half of the studies (n=27) were conducted in North America (n=27), and 25/54 employed a qualitative design. The advanced nurse practitioner role was diverse, working across the lifespan and with different patient groups. However, there was little agreement about the level of autonomy, or what constituted everyday activities. Team factors were the most frequently reported barrier and facilitator. Individual factors, lines of responsibility and ‘other’ factors (i.e. funding), were also frequently reported barriers. Facilitators included individual factors, supervision and leadership and ‘other’ factors (i.e. funding, planning for role integration). Conclusion: Building collaborative relationships with other healthcare professionals and negotiating the role are critical to the success of the implementation of the advanced nurse practitioner role. Team consensus about the role and how it integrates into the wider team is also essential