14,468 results for Doctoral

  • China’s Bids for International Events: A Study of Central - Local Relations

    Chu, Pok (2012)

    Doctoral thesis
    The University of Auckland Library

    Chinese cities have bid for international events since the 1980s. To increase their odds of success, central and local executive elites as well as central and local Party elites all participate in bids. The central and local executive elites are senior officials of the State Council, ministries and their affiliated units, and local governments. Their duty is to implement official bid tasks on behalf of the Chinese candidate cities. The central and local Party elites are members of the Chinese Communist Party Politburo Standing Committee and chairpersons of the local Party Committees. Their participation is to give support to the Chinese candidate cities. The pattern of division of labour between the central and local executive elites in implementing official bid tasks and the attitudes of both central and local Party elites in giving support are found to vary from case to case. This thesis intends to understand what factors have significant influence to shape the division of labour between the central and local executive elites in implementing each bid and the attitudes of both central and local Party elites in supporting each bid. Through reviewing Beijing's bid for the 2008 Olympic Games; Shanghai's bid for the 2010 World Expo; Guangzhou's bid for the 2010 Asian Games; and Shenzhen's bid for the 2011 Summer World University Games, the stipulations of international organisations are confirmed as a factor that has significant influence to shape the pattern of division of labour between the central and local executive elites in implementing each bid, and Factionalism is refuted as a factor that has significant influence to shape the attitudes of both central and local Party elites in supporting each bid. This thesis hence concluded that (1) China is a rule-abiding and effective international bidder, and (2) international norms have replaced local factionalism in shaping the behaviour of the Chinese officials in dealing with the duties assigned by international bodies. These findings imply that the Chinese government uses international bids to demonstrate its willingness and competence to bear the responsibility as a member in the international society.

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  • Investing in our young people: Akaupokotuanga i ta tatou mapu no te au tuatau ki mua

    Herman, Neti (2013)

    Doctoral thesis
    The University of Auckland Library

    Although most young people engage in positive life activities and become healthy adults, some become involved in risky behaviours. This has long been a concern for families, health professionals, policy makers and academics. Despite considerable research and the construction of a range of theories and interventions very little research has been done about young people in the Pacific, including in the Cook Islands where this thesis is based. The aim of this study is to address concerns about young people by developing a health promotion model in a Cook Islands context for young people in the Vaka Takitumu, a specific district of Rarotonga, and to contribute to scholarly debates on youth development. As a key step in developing this model, my research examined the health and wellbeing experiences of young people in the Cook Islands within a socio-ecological framework. This was guided by Community Based Participatory Research and Participatory Action Research approaches. This investigation explored the health behaviours of young people and how cultural identity, spiritual and health beliefs, and social networks impact on these behaviours. A community assessment was conducted with twelve focus group interviews, twenty key stakeholder interviews, and twenty key informant interviews, to examine concepts of health, the positive contributions by young people to themselves, their families and their communities; the issues and concerns faced by young people; and strategies for solving or minimising the impact of the issues and concerns identified by the participants. The results of this step suggested that a new paradigm using the Pu Ara Model which depicts a “health promotion” and “positive youth development” approach was powerful in the Cook Islands context. Young people voiced their need to be part of the big picture and to be part of the solution. The Pu Ara model emphasise strength-based and positive development outcomes. Young people need to belong, and be connected to family and communities to thrive. They also need to be empowered, have a voice, and learn the competencies and leadership skills to prepare them for adulthood, so they can engage and participate in meaningful activities and decision making, take responsibility for their actions and actively participate in civic discourse. This reflects a major shift in thinking in the Cook Islands, in that adults need to work in close partnership with young people in providing opportunities, learning experiences, and support. Ultimately, the implementation of the model needs a multi-sectoral collaborative effort by everyone, including young people, in the community. Keywords: Young people, community, health, wellbeing, health promotion, positive youth development, Pacific, Cook Islands, Vaka Takitumu.

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  • Underwater Anthropogenic Sound: Understanding the potential impacts on the marine environment and the influence on crab larval behaviour

    Pine, Matthew (2013)

    Doctoral thesis
    The University of Auckland Library

    There is a need to identify and better understand the impacts of underwater anthropogenic sound on the marine environment. For example, very few investigations concerning anthropogenic sound impacts on crustaceans have been published. Therefore, the research described in this thesis characterises potentially significant anthropogenic sound sources in New Zealand’s coastal waters and begins to determine their influence on the settlement-stage larvae of estuarine crabs. Several field-based experiments established that common sources of underwater anthropogenic sound in New Zealand were of appropriate intensities and frequencies to mask, over large areas, the natural underwater sounds found from several habitats. Laboratory-based experiments showed some anthropogenic sounds influenced the natural settling behaviour of settlement-stage larvae in several species of estuarine crabs. Notably, turbine sound was found to delay metamorphosis beyond a silent control. The research also characterised the ambient underwater acoustics from one of the largest estuaries in the world. Subsequent comparisons found that the sound from an operating tidal turbine was of greater intensity across the frequency range 0.1 – 20 kHz compared to the natural estuarine sound. The results also demonstrated that geometric spreading models are not accurate in shallow coastal waters and a simple model for the preliminary assessment of sound spreading was proposed based on field data. The findings presented in this thesis extend our knowledge of the role of natural underwater sound in mediating larval settlement in important coastal organisms. Specifically, this work demonstrated that anthropogenic sound may mask natural underwater sounds in estuaries and is likely to influence the patterns of settlement of estuarine crab larvae. Overall, the results raise concerns about potential long-term ecological impacts of anthropogenic sound in coastal marine habitats.

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  • Identifying Opportunities for Environmental Sustainability: A Grounded Study of the New Zealand Road Construction Industry

    Schaefer, Grace (2013)

    Doctoral thesis
    The University of Auckland Library

    The scale of the challenge presented by sustainable development is substantial. The required transformations are complex and multi-hierarchical, involving many different agents and significant social, institutional, and technological change. This thesis identifies opportunities to leverage institutional advancement towards environmental sustainability in the road construction industry in New Zealand. Legislative changes in the early 2000s had established sustainable development as a policy objective for local government and the land transport sector in New Zealand. However, in 2007, there existed an institutional and operational gap between these high-level policy objectives and the prioritisation and delivery of environmental sustainability outcomes in onthe- ground road construction activities. In response to this practical problem, this thesis examines the factors which motivated and influenced the greening of road construction firms and their activities, and the procurement of environmental outcomes by local road-controlling authorities. The thesis argues that road construction firms were motivated to explore environmental sustainability initiatives for several reasons, but predominantly adopted initiatives when these were expected to result in tangible outcomes for the firm. The commercial relationship between road construction firms and their clients was the key determinant with respect to the adoption of environmental sustainability initiatives by road construction firms. With respect to the purchase of environmental outcomes by local road-controlling authorities, it is argued that there had been no significant institutionalisation of environmental sustainability within the industry’s procurement and funding regimes. The existing ways of doing things and existing institutional structures still dominated how road-works were funded, procured, and constructed. Consequently, local asset managers did not feel justified in procuring beyondcompliance environmental outcomes in road-works. The thesis applies an exploratory, grounded theory method to develop empirically grounded and theoretically justified models of firm-greening behaviour and green public procurement in this industry. These models provide the credible basis on which to identify opportunities to leverage institutional advancement toward environmental sustainability. Opportunities are identified with respect to improving road construction firms’ capabilities and performance, and with respect to enabling the funding and prioritisation of environmental outcomes in the procurement of road-works by road-controlling authorities. The thesis argues that these opportunities remain relevant in the present context.

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  • Mechanisms of joint damage in chronic gout: The role of stromal cells

    Chhana, Ashika (2013)

    Doctoral thesis
    The University of Auckland Library

    Gout is an inflammatory arthritis caused by the deposition of monosodium urate (MSU) monohydrate crystals within and around the joint. It is the most common form of inflammatory arthritis affecting men and is a major cause of musculoskeletal disability in New Zealand. Cartilage and bone erosion are frequently observed in patients with chronic gout, and tendon rupture has also been observed in these patients. The mechanisms of joint damage in chronic gout are not yet fully understood. The aim of this work was to determine the role of stromal cells in the development of joint damage in chronic gout. Osteoblasts, chondrocytes and tenocytes isolated from primary tissues or appropriate cell lines were cultured in vitro with MSU crystals and changes in viability, gene expression, differentiation and function were analysed. The main findings of this study included reduced viability of all cell types tested; inhibition of mineralisation by osteoblasts and collagen deposition by chondrocytes and tenocytes; and decreased gene expression of osteoblastic, chondrocytic and tenocytic markers including collagens and cell-specific transcription factors and proteins. In addition, the gene expression levels of degradative aggrecanases were upregulated in chondrocytes cultured with MSU crystals. These in vitro findings were supported by analysis of joint samples from patients with chronic gout. In bone samples, osteoblast and lining cell numbers were reduced at sites adjacent to tophus, but not at sites away from tophus. Cartilage in these patients was highly disordered with a loss of normal architecture, and fragments of degenerative cartilage with few or no living chondrocytes were often observed. MSU crystals and tophaceous material were also identified invading tendon, within tendon and at the tendon-bone insertion site. These results suggest that stromal cells play an important role in the development and progression of joint damage in chronic gout, both through active degradation of joint tissues and reduced viability and function, which may limit the ability of the joint to repair itself following degradation.

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  • Development of a Conducting Polymer based Flexible Position Sensor for the Control of Hand Exoskeletons

    Tjahyono, Arief (2013)

    Doctoral thesis
    The University of Auckland Library

    There is an increasing demand for hand exoskeleton as they can enhance the capability of a healthy human hand beyond its natural capacity or rehabilitate a disabled hand impacted from injuries or serious illnesses such as stroke. At present, hand exoskeletons face an issue regarding to the sensors being employed to determine the finger position. These sensors utilise mechanical designs that require physical movements of rigid components. As such, these sensors are bulky and heavy. They inhibit the usability and portability of the hand exoskeleton that prevent a comfortable usage of the devices and their deployment to the patients' homes. This has been addressed by the development of a flexible position sensor. This sensor combines two types of polymer to construct the sensor. Natural rubber is employed as the substrate and chosen for its flexibility, elasticity and resilience. The role of strain sensing was assigned to a conducting polymer called polypyrrole in its thin film form. It has been chosen for its high conductivity, stability, ease of synthesis and its proven ability to measure strain. The sensor was fabricated using chemical vapour deposition to carry out the in situ polymerisation of polypyrrole on the natural rubber substrate using the vapour phase polymerisation. This produces a polypyrrole thin film with uniform, smooth and dense surface morphologies that are desired for this sensor. Prior to the deposition, the substrate was conditioned by pre-straining the natural rubber substrate to 20 % and followed by an O2 plasma treatment set to 200 W for 40 seconds to reduce the surface hydrophobicity. This helps with the adsorption of the FeCl3 oxidant and adhesion of the polypyrrole thin film to the substrate. Various deposition parameters were analysed and the optimised parameters were found to be 0.5 M FeCl3 oxidant, 0.1 M pyrrole monomer and two hours polymerisation duration. The strain sensing mechanism was established to be the elongation of the polymer chains in the polypyrrole thin film with the addition of surface micro-cracks that open up with the elongation of the polypyrrole thin film to induce changes in the electrical resistance. However, the electrical resistance of the sensor drifts upward between subsequent measurements. A calibration process was implemented by measuring the change in the electrical resistance instead of the value itself. As such, the sensor measures the relative position instead of the absolute position. The sensor has a linear relationship between the electrical resistance and the measured strain with a gauge factor in the range of 1.74 to 2.02. The error was estimated to be ±10 % when analysed from repeated strain test cycles. Meanwhile, the sensor exhibits a non-linear relationship between the electrical resistance and the angular displacement due to a non-linear strain distribution during a rotary position measurement. When implemented as the feedback in a closed loop control system, the sensor displays good performance. It was able to measure linear and angular positions with an error of 1 mm and 5° respectively. The combination of materials used in the strain sensor fabricated in the structure used in this research has not been done previously. Using a non-absorbent and yet, a soft, flexible and elastic material such as rubber means the available fabrication process has to be modified and adapted. This includes the use of acetonitrile as the solvent in the deposition process for its compatibility with natural rubber due to the similarity of the solubility constant for both materials. Utilising a vacuum assisted solution evaporation process to generate the pyrrole vapour is also crucial in maintaining the rubber substrate at its desired state and condition. Overall, the modification and adaptation of the available fabrication process has lead to a simple and controllable sensor fabrication process that is highly compatible for mass production. The sensor aims to address the issues associated with the finger position monitoring for hand exoskeletons. This has been achieved by the lightweight and low profile characteristics of the sensor. The sensor can operate discreetly and unobtrusively while adding negligible weight to the hand exoskeleton. Such a sensor can help to make the hand exoskeleton more portable and comfortable to use to enhance the rehabilitation process or strength augmentation.

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  • Oncogenic functions of ARTEMIN in ER negative mammary carcinoma

    Banerjee, Arindam (2013)

    Doctoral thesis
    The University of Auckland Library

    ARTEMIN (ARTN) is an estrogen regulated gene. The expression of ARTN promotes resistance to antiestrogen therapies; therefore, patients with estrogen receptor (ER) positive mammary carcinoma (ER+MC) treated with tamoxifen have poorer survival outcome. ARTN is also expressed in ER negative mammary carcinoma (ER-MC). Herein, I have demonstrated that ARTN promotes TWIST1 dependent epithelial to mesenchymal transition (EMT) of mammary carcinoma cells, which is associated with metastasis and poor survival outcome. ARTN modulates the expression of TWIST1 via AKT1 dependent signalling in ER-mammary carcinoma (ER-MC) cells. siRNA mediated depletion of TWIST1 abrogated ARTN stimulated cellular behavior associated with metastasis, and forced expression of TWIST1 abrogated the functional effects of ARTN depletion. Next, I also found ARTN mediated acquired resistance of mammary carcinoma cells to ionizing radiation (IR) or paclitaxel resistance by promoting TWIST1-BCL-2 dependent cancer stem cell-like (CSC) behavior. Herein, I have demonstrated that ARTN modulates the expression of CSC-like cells by increasing mammospheres, ALDH1+ populations. Furthermore, increased ARTN expression was significantly correlated with ALDH1 and BCL-2 expression in an ER-MC patient cohort. Forced expression of ARTN also dramatically enhanced tumour initiating capacity of mammary carcinoma cells in xenograft models at low inoculums. In addition, I have reported ARTN modulations of endothelial cell behavior and resultant increase of angiogenesis in ER-MC. ARTN promoted endothelial cell proliferation, migration, invasion and 3D matrigel tube formation. Angiogenic behavior promoted by ARTN was mediated by AKT1 with resultant increased TWIST1 and subsequently VEGF-A expression. In a patient cohort, ARTN was positively correlated with VEGF-A expression. In xenograft, ARTN produced tumours exhibited increased VEGF-A expression and microvessel density (CD31 and CD34) compared to tumours formed by control cells. Functional inhibition of VEGF-A by siRNA or bevacizumab (a humanized monoclonal anti-VEGF-A antibody) partially inhibited the ARTN mediated angiogenic effects of ER-MC cells. Thus, ARTN co-ordinates and regulates multiple aspects of tumour growth and metastasis in mammary carcinoma.

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  • Interference Control of Indoor Cognitive Radio Systems

    Ho, Meng-Jung (2013)

    Doctoral thesis
    The University of Auckland Library

    To enhance the e ciency of spectrum utilisation, the broadcast television (TV) (pri- mary) bands are currently open (or to be opened) for unlicensed (secondary) operation by spectrum management regulators around the world. Nevertheless, a considerably large geographic area still remains excluded from the secondary operation due to potential in- terference to the licensed (primary) users. The area of exclusion lies within the protection contour around each TV transmitter. This thesis explores possible re-use of the primary spectrum within the protection contour. This thesis investigates the aggregated interference power (AIP) in a broadcast TV system due to multiple transmitting secondary users (SUs). The COST-231 building pen- etration model is also used in this investigation to assess the bene t of re-using spectrum indoors. It is identi ed that there is an opportunity to use primary spectrum within the protection contour if the re-use occurs inside a building that shields radio signals and re- duces interference to the primary system. However buildings typically do not have equal radio shielding ability. The SUs will be required to adjust their transmit powers according to their locations in the building in order to minimise the interference to outdoor primary users (PUs). A novel localisation-less indoor cognitive radio (CR) system is developed allowing SUs to access the primary spectrum inside a building within the protection con- tour. The system utilises an indoor sensor network for i) interference sensing, ii) transmit power control, to limit the interference to the outdoor primary receiving antennas. A power control model of the indoor system is developed to estimate permissible transmit power for the indoor users. A power control algorithm is developed as a practical imple- mentation of the power control model and its e ectiveness is assessed through simulations in which realistic propagation scenarios are considered, e.g. when internal partition walls and multipath fading are present. Mixed indoor/outdoor propagation measurements have also been conducted to con rm the applicability of the COST-231 building penetration model, which was developed to predict outdoor-to-indoor penetration loss, in the scenarios considered in this thesis. It is also shown that interference measured by sensors deployed inside the buildings can be used to control the interference occurring at outdoor locations.

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  • Mechanics of Flexible Composite Hull Panels Subjected to Water Impacts

    Allen, Thomas (2013)

    Doctoral thesis
    The University of Auckland Library

    Dynamic impacts between a marine craft’s hull and the water surface is one of the critical load cases considered for hull structural requirements, particularly for high speed small craft. These impacts, referred to as slamming, generate highly dynamic loads, which have both local and global effects. This work focused on obtaining high quality measurements of the loading and responses of flexible hull panels during slamming events. Significant research into slamming loads and pressures has previously been undertaken, dating back to 1929, however there is a lack of experimental data on flexible structures accurate enough to allow for validation of methods for predicting structural response. A series of 1030 x 600 mm single skin and sandwich composite panels with flexural rigidities between 1,540 and 20,100 Nm have been tested in constant velocity impacts up to 6.0 m/s with deadrise angles of 10, 20 and 30 using a purpose built testing facility. The results from these tests have been compared with previous experimental work undertaken on a nominally rigid panel. Additionally a range of analytical theories for the prediction of the loads and pressures acting on a rigid wedge have been compared to the experimentally measured values. The hydroelastic effects during slamming of flexible structures have been characterised. Significant decreases in peak pressure at the centre of up to 50% and increases at the outer edge of the panel of up to 100% have been seen, both of which are predominately attributed to kinematic changes during the impact. Previous inertial based hydroelasticity onset theories are shown to be unsupported by the experimental data, with the greatest effect of inertial effects occurring at the lowest impact velocities. Strains in the long direction of the panel of up to 50% of the strain in the short direction have been recorded at the centre of the panel, illustrating the importance of considering a rectangular panel undergoing slamming impacts as three dimensional. Transverse shear force at the outer edge of the panel has been characterised and shown to be significantly higher than that predicted from traditional design methods. A range of numerical models, including a full dynamic Combined Eulerian Lagrangian model have been developed and their ability to predict the panel responses assessed.

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  • Language use and workplace participation in the identity construction of Bumiputera Malay undergraduates in Malaysia

    Adnan, Airil (2013)

    Doctoral thesis
    The University of Auckland Library

    Malay identity in research literature is often constructed as an essentialised bond between ethnicity (Bumiputera Malay), religion (Islam) and language (Bahasa Melayu). This study presents a contemporary reading of Bumiputera Malay identities by focusing mainly on language use but also taking into account the adat (culture) and jiwa (soul) as part of Malay sociohistory. Towards this aim, I examined the roles of three languages (Bahasa Melayu, English and Mandarin Chinese) in the process of identity construction for a group of Bumiputera Malay undergraduates from a Bumiputera-exclusive university in Malaysia before, during and after their industrial attachments in the final semester of their diploma studies. Working within a part essentialist and part post-structuralist framework, I carried out my fieldwork in two cycles from December 2010 to April 2011. In the first cycle, a survey instrument was used to profile 102 undergraduates from the university’s Administration and Management Faculty. Then, in the longer second cycle, eight focal students were invited to participate further. Multiple qualitative instruments were employed to collect data as these students carried out their work roles within the private sector. Using a communities of practice theoretical framework (Wenger 1998, 2009) analysis of the data revealed the interrelationships between their language use and workplace participation. The findings point to three critical phases in the process of identity construction: campus, working and future life; these are interconnected phases within their ‘life journey’. The life journey, as both process and product of identity construction, opens up multiple vantage points where the past, present and future of the undergraduates, both real and imagined, came together. This, in turn, helped them not only to imagine the selves that they wanted to become but also to exert their agency and influence episodes within their day-to-day lives. As they used the languages that they know and participated in their workplace communities, identities were constructed and reconstructed. Although not all their language and workplace experiences were useful in shaping their life trajectories, on the whole, the eight participants began to explore future possibilities when they utilised the attachment as proving grounds for themselves as young urban professionals.

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  • Do You Bind? The Representation of Visual Features and Objects in Working Memory

    Roberts, Reece (2013)

    Doctoral thesis
    The University of Auckland Library

    A central debate in visual working memory research centres on the nature of visual working memory representations. The object account proposes that the fundamental units of visual working memory are integrated representations, such that items are stored in working memory in an all-or-none fashion. The feature-channel account, on the other hand, proposes that visual features are stored independently of each other. According to this account, additional representations are required to code for the associations between visual feature dimensions. Change-detection tasks are a commonly used paradigm to investigate the representational format of visual working memory. Performance in detecting novel visual features (novel changes) can be compared with detecting a recombination of visual features (binding changes) in this paradigm. While presenting a single-item as test display produces equal performance in novel and binding changes, there is disagreement about whether multi-item displays preferentially disrupt performance in binding changes. In Study 1, I showed that while a multi-item test display results in worse performance for binding conditions relative to novel colour and novel letter conditions when novel locations are used for the test display, this effect is alleviated if an informative retroactive cue is presented in the delay period. In Study 2, I used a two-alternative forced choice task to investigate the representational format of visual working memory. Participants were presented with three coloured shapes which they had to maintain in visual working memory. They were then presented with two items and had to select, using the mouse, which item was from the original display (the target). The other item (the lure) was either a recombination of visual features from the original memory display (binding condition) or contained a novel visual feature (novel colour and novel shape conditions). Mouse trajectories showed greater complexity and curvature for the binding condition, supporting the hypothesis that visual working memory stores information in parallel visual-feature channels. Study 3 explored whether the critical process disrupting working memory for binding information in change-detection tasks with multi-item test displays tasks is the perceptual binding of visual features. This was achieved by presenting two versions of a secondary visual search task in the delay period of a change-detection task with a single-item test display. One was a conjunction search which required the binding of visual features; the other was a “pop-out” search. Only the conjunction search task disrupted working memory for binding information more so than maintenance of visual features. Finally, a neural-cognitive model is proposed that highlights the role of posterior parietal regions in coordinating the binding of visual features across the domains of visual perception and visual working memory.

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  • The contribution of people’s attitudes and perceptions to the acceptance of eldercare robots

    Stafford, Rebecca (2014)

    Doctoral thesis
    The University of Auckland Library

    The number of people aged over 65 years is increasing worldwide, and this is placing increased demand on healthcare services. Engineers have proposed that eldercare robots may be able to meet the increasing healthcare needs of the aging population; however eldercare robots have not yet been widely adopted. Reasons for this are likely multifaceted, but one reason may be insufficient attention to the psychological aspects of the human robot interaction (HRI) in eldercare. Technology acceptance models indicate that people’s perceptions of technology attributes (particularly perceived usefulness) predict technology acceptance more strongly than more objective design parameters. However, little research to date has investigated the importance of perceptions to the acceptance of eldercare robots. The central thesis of this PhD is that older people’s perceptions will influence their acceptance of healthcare robots. Specifically, three main perceptions are studied - older people’s perceptions of their own unmet needs, their attitudes towards robots in general, and their perceptions of the robot’s mind. It is proposed that more positive attitudes and perceptions of robots will predict better acceptance of healthcare robots. This thesis contains four peer reviewed publications. One is a discussion paper on the importance of assessing the unmet needs of eldercare stakeholders in order to develop more useful and acceptable robots. Three publications present the results of three different Human Robot Interaction (HRI) trials conducted with prototype healthcare robots. All three studies employed autonomous service-type robots and older participants, and two of the three HRI trials were conducted within real-world eldercare environments. The key findings of the HRI studies were that people’s perceptions of robots and ‘robot mind’ predicted robot acceptance. In all three studies, participants’ ‘pre-interaction’ generic robot attitudes predicted acceptance of specific robots. This suggests that even people who have never used robots before can hold mental models of robots that influence robot acceptance. Additionally, people’s robot attitudes improved after interacting with the robot, and these changes also predicted robot acceptance. This suggests that a positive HRI is important for robot acceptance. Compared with people who perceived robots as possessing more mind, people who perceived robots as having less mind were more likely to use a robot. Furthermore, despite robot-users perceiving less robot-mind at baseline, they perceived the robot to have even less mind after interacting with it. While this result suggests that people may hold unrealistically high perceptions of a robot’s mind which may be a barrier to acceptance, it also suggests that these perceptions are revised downwards after actually experiencing a robot’s capabilities. In conclusion, older people’s perceptions and attitudes towards robots do predict eldercare robot acceptance. Future implications of this work are that building robots that meet the specific unmet needs of older people and paying more attention to users’ perceptions of robots may increase the acceptance of eldercare robots. Future research should investigate whether interventions designed to promote realistic and adaptive perceptions of robots in older people can increase the acceptance of eldercare robots.

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  • The effects of post-term birth, hyperemesis gravidarum, and birth order on childhood metabolism and body composition

    Ayyavoo, Ahila (2013-12-11)

    Doctoral thesis
    The University of Auckland Library

    Background: There is increasing evidence that early life events have major implications for health in later life. For example, studies at Liggins Institute have shown adverse metabolic outcomes in children and adults born small-for-gestational-age or preterm. In this thesis, glucose homeostasis and body composition (amongst other assessments) were evaluated in three under-explored groups of children, i.e. those i) born post-term (≥42 weeks gestation), ii) born of mothers who suffered from severe hyperemesis gravidarum, and iii) first-borns. Participants: Healthy pre-pubertal children, aged 4–11 years, naturally conceived, born of singleton pregnancies and of birth weight appropriate-for-gestational-age (birth weight >-2 and <2 standard deviation scores), recruited in Auckland, New Zealand. Methods: Primary outcome was insulin sensitivity measured using intravenous glucose tolerance tests and Bergman’s minimal model. Other assessments included body composition from wholebody dual-energy X-ray absorptiometry, fasting hormonal concentrations and lipid profiles, 24-hour ambulatory blood pressure monitoring, and inflammatory markers. Results: We found that i) post-term children had a 34% reduction in insulin sensitivity in comparison to controls born at term, and also displayed a number of early markers of the metabolic syndrome; ii) children born to mothers who experienced severe hyperemesis gravidarum had insulin sensitivity that was 20% lower than that of controls; and iii) although first-born children were taller and slimmer, these children had a 27% reduction in insulin sensitivity and higher daytime blood pressure compared to later-borns. Conclusions: We have identified three common groups of children (those born post-term, born of mothers who suffered from hyperemesis gravidarum, and first-borns) who are likely to be at an increased risk of developing type 2 diabetes mellitus and other metabolic and cardiovascular diseases later in life. Therefore, long-term follow up of these groups into adulthood is important, so that potential long-term adverse health effects can be better evaluated.

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  • Mechanical Properties of Lightweight Sandwich Panels with Corrugated Plywood Core

    Kavermann, Stephen (2013)

    Doctoral thesis
    The University of Auckland Library

    Lightweight and sustainable panels are desired for many applications, including wall linings, ceilings and decorative xtures. The focus of this thesis were sandwich panel structures sourced from Radiata pine wood, a renewable and biodegradable raw material. Major objectives were to characterise, and develop models to predict, key mechanical properties of the novel corrugated plywood sandwich core and overall sandwich structures. Tensile, bending and shear tests were carried out on the base plywood material to establish orthotropic properties for subsequent modelling, with signi cant in-plane values determined to be EL=10.2 GPa, ET =0.15 GPa and GLT =0.85 GPa. Numerical models were developed to predict out-of-plane properties of the corrugated core, and were compared with compression and block shear experiments, and existing analytical solutions. In single corrugation tests, 1-ply and 2-ply laminate models were found to match experiments well, while the sti ness and strength of 3-ply specimens were over-predicted. Numerical nite element (FE) predictions of sti ness and strength for shear along and across the corrugations, through-thickness compression, and corrugation bending also exceeded experimental results. It was concluded that the plywood laminate was damaged during forming, reducing elastic mate- rial properties and, more signi cantly, the strength of interlaminar adhesion. Unit-cell models were used to investigate several di erent core con gurations and pro le geometries, including bi-directional corrugations and circular-straight pro les. FE models predicted the behaviour of four point bend tests reasonably accurately, presum- ably due to face-sheets being una ected by forming. Sandwich beams often showed signi cant through-thickness compression under the loading points, and failure modes observed included face-sheet buckling and excessive shear deformation. Vibration testing revealed that beams generally behaved as homogeneous below 1.5 kHz, but after this signi cant core breakup was observed. FE models predicted the free-free modes of vibration of beams well to higher frequencies, and revealed unique modes caused by the corrugated core. In conclusion, the mechanical behaviour of corrugated plywood sandwich structures has observed in several critical load cases. With this understanding, such sandwich panels show great potential for application. Avenues of future work are nally suggested, including pro le forming, investigating certain mechanical tests, and potential modi cations for FE models.

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  • The structure and function of ZPI, and the role of ZPI deficiency in venous thrombosis

    Young, Laura (2012)

    Doctoral thesis
    The University of Auckland Library

    Protein Z dependent protease inhibitor (ZPI) is a plasma inhibitor of factors Xa and XIa. In an earlier study, five mutations were identified within the ZPI gene of venous thrombosis patients and healthy controls. Two of these were nonsense mutations and three were missense mutations within the D helix (F145L and S143Y) and β sheet A (Q384R). Recombinant wildtype and mutant proteins were prepared in Escherichia coli to compare the stability and kinetics. The wildtype protein efficiently inhibited Xa (in the presence of its cofactor, protein Z) and also XIa, particularly in the presence of unfractionated heparin, suggesting a physiologically important role for heparinoids in vivo. The two D helix mutations were readily expressed and had similar stability to the wildtype in response to thermal challenge, however the yield of the Q384R variant was low; inhibition of Xa in the presence of protein Z was markedly reduced with no measurable inhibition of XIa by this protein. The inhibition of XIa by the F145L mutant was reduced 2-3 fold compared to the wildtype. An analysis of all five ZPI mutations was undertaken in a cohort of venous thrombosis patients (n=550) compared to healthy controls (n=600) to correlate possible ZPI deficiency with thrombosis risk. Overall, there was a modest increase in incidence of these mutations in the thrombosis group (OR 2.0, 1.05-3.7, p=0.044) however in contrast to W324X (nonsense mutation), the Q384R missense mutation and R88X nonsense mutation were evenly distributed in patients and controls; F145L was rare. The final mutation (S143Y) was also rare and did not significantly alter ZPI function in laboratory studies. The nonsense and Q384R mutations reduced plasma ZPI in both patients and controls, although there was no difference in ZPI levels between the two groups overall. The F145L and particularly the Q384R mutation impaired the function of the coagulation inhibitor ZPI, however there was no convincing association between these functional mutations, the nonsense mutations and venous thrombosis risk. The functional role for ZPI in vivo has yet to be clarified.

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  • Synthesis, Properties and Applications of Micro/Nano Zinc Oxide Spheres

    Zhan, Xinghua (2013)

    Doctoral thesis
    The University of Auckland Library

    The semiconductor material of zinc oxide (ZnO) has been studied intensively for decades due to its numerous unique electrical and optical properties, such as wide bandgap, high exciton binding energy at room temperature, and high refractive index. These properties can lead ZnO material to the applications of electronics and optoelectronics. More importantly, the realization of various kinds of ZnO micro- or nano-structures, makes ZnO capable to improve the electrical and/or optical performances of the devices. Different micro- or nano-structured ZnO has attracted much attention from researchers worldwide in the recent years as this will bright the future of ZnO in the applications of light emitting diodes (LEDs) and solar cells. And thus, developing a simple, low-cost, and environmental friendly method to grow ZnO having desired micro- or nano-structures is of great importance in the research field of ZnO material, and this becomes a key issue when a large-scale production is required in the industry. Meanwhile, the parameter control during the synthesis procedure is essential to be modified and clarified. The main focus of this thesis is on developing a simple, inexpensive, and solution based thermal method to grow spherical shaped ZnO particles having uniformly distributed size. The growth parameters for controlling the size and shape, such as the hydrate, solvent, salt concentration, reaction temperature, reaction time, seed solution, and heating rate, are experimentally studied and clarified in this thesis. This method has the advantage of large-scale production and good reproductivity with low requirements in regard to the facilities and experimental conditions in industry. At the same time, the related growth mechanism of the submicron ZnO spheres is studied, derived, and theoretically analyzed in this thesis, based on the observation in the experiments. Another focus of this thesis is on the study of the surface morphologies and optical properties of the synthesized ZnO particles. The surface morphologies are analyzed by the techniques of field emission scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The optical properties of the synthesized ZnO particles are experimentally investigated by Raman spectroscopy and photoluminescence at room temperature. Furthermore, the related luminescence mechanism is theoretically studied, modelled, and presented in this thesis. In order to explore the applications of the synthesized ZnO spheres, the composite of ZnO/V2O5 (zinc oxide/vanadium pentoxide) is designed, fabricated, experimentally investigated, and theoretically analyzed. The experimental results indicate that this transition metal oxide mixture can be developed to create a group of new light emission materials with high efficiency. Moreover, a silicon-based ZnO light emission device is presented in this thesis, reporting that visible light emission is observed at room temperature from the ZnO material which deposited on the hot electron emitting substrate (HEES). Finally, some of the future works of this research are suggested.

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  • Refugee Youths: Adaptation and Mental Health Service Provision

    Choummanivong, Chaykham (2013)

    Doctoral thesis
    The University of Auckland Library

    Adolescents comprise a significant portion of refugees, yet little is known about the particular challenges this group faces in resettlement, or their needs for mental health service provision. Fifty three adolescents from refugee backgrounds were recruited to participate in focus group discussions and structured interviews to investigate stressors experienced throughout the pre-migration, transit and post-migration stages, their coping strategies, and experiences with and attitudes to mental health services. In addition, focus groups were also completed with 20 mental health service providers. A thematic analysis revealed issues of dealing with loss, worry about family left behind, discrimination, money worries, difficulties with learning a new language, struggles to make friends, adjusting to the new culture and school, and family conflict. Adolescents regarded coping with such stressors as being something to be done privately – rather than through talk with others - but described a range of other coping mechanisms they use. Barriers to accessing mental health services included differences in cultural understandings of their issues, challenges associated with use of interpreters , fear of stigma, and fear of privacy not being maintained. Service providers identified refugee adolescents’ mental health difficulties arising from trauma and its lingering impact, clash of cultures, loss, missing relationships, lack of meaningful activities, lack of financial resource, different rates of adaptation to parents, parent’s lack of familiarity with the parent role, family health and functioning, parents’ expectations and family’s attitude towards mental health services. Service providers further identified language difficulties and different cultural understandings impacted on the wide range of intervention they provided. Adolescents and service providers identified a range of options for improving service delivery to refugee adolescents. Implications of this research are presented for resettlement programmes and mental health care.

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  • Functional studies of the Arabidopsis thaliana dormancy associated genes, DRM1 and DRM2

    Rae, Georgina (2013)

    Doctoral thesis
    The University of Auckland Library

    Plants must carefully regulate their development in order to survive the prevailing conditions. One aspect of this of particular importance is dormancy release - meristematic tissues deciding when to grow and when not to, given varying conditions. In order to better understand the growth release mechanism of dormant tissue at the molecular and physiological levels molecular markers can be used. Members of the DRM1/ARP (DORMANCY ASSOCIATED GENE-1/AUXIN-REPRESSED PROTEIN) gene family are routinely used as markers for dormancy release. This plant-specific gene family has high sequence identity at the protein level throughout the plant kingdom, but its function in planta remains undetermined. The aim of this PhD project is to gain insight into the function of the dormancy associated genes DRM1 and DRM2 in Arabidopsis thaliana. A multi-faceted approach, including bioinformatic, molecular and biochemical studies, was adopted. The Arabidopsis DRM1/ARP gene family includes five members, the resulting proteins of which are predicted to be intrinsically disordered in nature. These family members are differentially regulated across development at the transcript level, with both constitutive and floral-specific, non-meristematic profiles evident. Both AtDRM1 and AtDRM2 produce splice variants which differ in their transcriptional response to various abiotic factors. Over-expression of AtDRM1 or AtDRM2 causes subtle developmental retardation. While null mutants do not exist for either gene, down-regulation amiRNA lines were analysed and exhibited subtle increases in bolt height compared with wildtype. Attempts to express His6-tagged AtDRM1 or AtDRM2 recombinant protein in E.coli yielded no expression, while expression attempts in a cell-free system produced an insoluble product. This protein is readily degraded in vitro, possibly as a result of its lack of intrinsic structure. Yeast-2-hybrid assays showed that neither AtDRM1 nor AtDRM2 bind with the branching pathway protein AtBRC1 and a lack of putative binding partners retrieved from a Yeast-2-hybrid library screen suggests that binding may be phosphorylation-dependent. Overall these findings lead to the hypothesis that AtDRM1 and AtDRM2 may be hub proteins acting in a general stress response pathway, specifically involved in the early modulation of protective growth prevention signals.

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  • Quantitative analysis selection in education: Potential impacts on researchers' conclusions

    Meissel, Kane (2014)

    Doctoral thesis
    The University of Auckland Library

    This thesis utilises literacy data from a large professional development project in New Zealand schools to investigate the implications of researcher decisions about approaches to quantitative analysis. Specifically, the main research question posed is the extent to which the selection of particular analyses leads to incomplete or even erroneous conclusions when using real-world data. There are various publications advocating for particular methodologies based on this notion, but many of these use simulated data or extreme cases specifically chosen to demonstrate the advantage of the particular method being advocated. This use of simulated and manipulated datasets may explain why many researchers persist with analyses that are argued to be less than ideal. In this thesis, the implications of analysis choice are investigated using increasingly complex analyses, including effect sizes, single-level regression and multi-level models, with the results and conclusions made from each set of analyses collated and compared. A secondary aim was to evaluate how effectively the professional development project raised student achievement in literacy, and whether these shifts contributed to more equal outcomes for subgroups of students. Much of the previous research where student achievement is linked to professional development has been inconclusive. This inconclusiveness arguably increases the burden of evidence when examining the effect of professional development on student outcomes, so the extensive analyses utilised to investigate the primary thesis aim are especially useful in this regard, and support an in-depth examination of this secondary aim. The results of the investigations undertaken throughout this thesis showed that the professional development typically resulted in acceleration of progress rates (especially in writing) for all priority subgroups; including students in low socioeconomic catchment areas, and those of minority ethnicities. Choice of analysis was found to be of comparatively minimal importance when considering main effects, but secondary effects were susceptible to sometimes considerable differences in conclusions depending on the method of analysis used. These differences were of sufficient magnitude that policy decisions would likely differ depending on the type of analysis used to infer conclusions.

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  • A Qualitative Investigation of Young Adult Stepchildren’s Experiences of Stepfather Authority

    Mitchell, Jessica (2013)

    Doctoral thesis
    The University of Auckland Library

    Stepfamily formation can be challenging for adults and children, particularly in regard to stepparent-child relationships, which are crucial for stepfamily functioning and child well-being. Stepparent authority is a particularly challenging and ambiguous area. This thesis investigated the range of young adult stepchildren’s experiences and perceptions of stepfather authority, particularly those perceived or identified as either positive or problematic. This thesis study comprised two studies: a self-report online questionnaire, and semi-structured interviews. Eighty-eight young adult stepchildren completed the questionnaire. Ten participants were selectively chosen to be interviewed from volunteers who completed the questionnaire and reported mainly positive experiences with stepfather authority. This was in order to provide insight into positive experiences of stepfather authority and processes that are associated with an acceptance of stepfather authority. Both studies were qualitative and the data was analysed using thematic analysis. The questionnaire results indicate that most participants experienced both positive and difficult aspects of stepfather authority. Participants identified that caring and practical and emotional support, including guidance and advice, were positive aspects of stepfather authority. Perceived warmth and support often led to increased respect for the stepfather and a positive relationship developing, which for some led to an acceptance of authority. Several benefits of authority were identified, including enhanced self-esteem and gaining a ‘father figure’. Some participants identified that the stepfather having no authority was positive. Difficult experiences related to the stepfather not being a biological parent, the stepfather attempting to adopt an authority role at an inappropriate time, adjustments to a new authority figure, authoritarian and harsh discipline, and negative impacts on the parent-child relationship. There were a range of opinions regarding stepfather influence, with the majority of participants stating the stepfather could have influence if certain conditions were met, especially if a positive relationship with the stepfather had developed. There were a range of experiences with stepfather authority identified in Study Two. Some participants reported difficulties, although all reported positive experiences overall. All participants’ mothers maintained the primary disciplinarian role initially. A number of these participants described stepfathers taking a cautious approach to discipline initially and establishing a positive relationship with them, which allowed for his authority to be accepted. A caring attitude and support from the stepfather, and support of the mother were often reported. iii The disciplinary role of the stepfather tended to increase over time. Participants perceived benefits to the stepfather’s influence and discipline. Implications for stepfamily systems and clinical work with stepfamilies are discussed along with future research directions.

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