12,567 results for Doctoral

  • International Student Mobility and Internationalisation of Universities - The role of serendipity, risk and uncertainty in student mobility and the development of cosmopolitan mind-sets through knowledge and intercultural competence. Employability, students’ future mobility aspirations and the EU’s support of international student mobility

    Weibl, Gabriel (2014)

    Doctoral thesis
    University of Canterbury Library

    The background to this study lies in the discrepancy between the perceptions of international student mobility in the context of the internationalisation of higher education by the EU and universities on one hand and international students themselves in terms of their motivations to study abroad on the other hand. This is a comparative study based on three main case studies, of six universities in New Zealand, Oxford University in the UK and the Charles University in the Czech Republic. It explores the students’ experiences abroad in terms of their intercultural competence, the shaping of identities, the acquisition and transfer of knowledge, the possible forming of cosmopolitan mind-sets and empathy, perceptions of employability and their future mobility aspirations. This thesis also considers the barriers and ‘push and pull’ factors of mobility, perceptions of risk and uncertainty in regards to mobility and the role of serendipity in student mobility, which has been overlooked in the literature on mobility and migration. The theoretical framework of the study builds on social capital theory, Europeanisation and the ‘do-it-yourself biography’ theory. The nature of this topic, however, suggested the employment of the concepts of globalisation, transnationalism and consideration of other forms of capital, such as the total human capital, mobility capital and transnational identity capital. This is predominantly a qualitative, mixed-method and longitudinal research project, which uses surveys, case studies, interviews and the data collecting tool called grounded theory. It triangulates data to support and enhance the analytical validity of the thesis. This research concludes that student experiences abroad as well as the internationalisation efforts of universities and the EU would benefit from the introduction of education for global citizenship, which should focus on the intercultural competencies of students. The thesis suggests sociocultural elements for example the cosmopolitan mind-set can enhance the economic, academic and political rationales of internationalisation, such as employability.

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  • Discovery of novel circular replication-associated protein encoding single-stranded DNA viruses in ecosystems using viral metagenomic approaches

    Dayaram, Anisha (2015)

    Doctoral thesis
    University of Canterbury Library

    The introduction of next-generation sequencing (NGS) technologies has dramatically changed the field of virology, with many significant discoveries of novel circular replication-associated protein (Rep) encoding single-stranded (CRESS) DNA viruses. Traditionally, most research into CRESS DNA viruses has often focused on investigating plant and animal pathogens that are of significant economic importance. This research has led to the discovery and establishment of three different CRESS DNA families including Geminiviridae, Nanoviridae and Circoviridae, which infect eukaryotes. CRESS DNA viruses can have single or multicomponent genomes, with the latter requiring all components for infection. CRESS DNA viruses have circular single-stranded DNA (ssDNA) genomes with at least one protein encoding a Rep which is responsible for viral replication. It has been shown that CRESS DNA viruses are able to evolve rapidly with nucleotide substitution rates that are similar to those observed in RNA viruses. The Rep gene has conserved regions known as motifs which are often used to determine relatedness between CRESS DNA virus. NGS has expanded our knowledge on the diversity of novel CRESS DNA viruses. Viral genomes are now routinely recovered from different sample types without any prior knowledge of the viral sequence. This has led to the development of the field of viral ecology. This field places an emphasis on viruses being one of the most abundant organisms on earth, and are therefore likely to play a major role in ecosystems. Environmental metagenomic studies have isolated CRESS DNA viruses from sea water, freshwater, faecal matter from various animals, soil, the atmosphere, sediments and sewage; dramatically increasing the known CRESS DNA viral genomes in the public domain. These studies are shedding light on the distribution of CRESS DNA viruses, as well as providing baseline data for future studies to examine virus-host interactions, community structure and ultimately viral evolution. Vector enable metagenomics (VEM) is another novel approach utilising NGS techniques for discovering CRESS DNA viruses. As many plant-infecting CRESS DNA viruses such as geminiviruses and nanoviruses are vectored by insects, this approach exploits this mechanism by using insect vectors as a surveillance tool to monitor and survey these viruses circulating in ecosystems. Recent studies have used these methods to identify known viral plant pathogens as well as novel viruses circulating in insect vectors such as whiteflies and other higher order insects such a mosquitoes and dragonflies. These approaches successfully demonstrated that VEM can be used as a unique method, with the first mastrevirus discovered in the new world being recovered from dragonfly species Erythrodiplax fusca using this approach. The research in this thesis uses metagenomics to survey CRESS DNA viral diversity in different organisms and environments. Two hundred and sixty eight novel CRESS DNA viruses were recovered and verified in this study from a range of sample types (adult Odonata, Odonata larvae, Mollusca, benthic sediment, water, Oligochaeta and Chironomidae) collected in the United States of America, Australia and New Zealand. All viral genomes isolated had two major proteins encoding for a putative Rep and coat protein (CP), with major Rep motifs identified in most Reps. Phylogenetic analysis of the Reps encoded by the viral genomes highlighted that most were extremely diverse falling outside of the previously described ssDNA viral families. A top-down approach was implemented to recover CRESS DNA viruses and possible viral pathogens from Odonata and their larvae. Thirty six viral genomes were recovered from terrestrial adult dragonflies as well as the twenty four from aquatic larvae. Dragonfly cycloviruses were isolated from the some adult Odonata species which were closely related to the isolates previously described by Rosario et al. (2012). The viruses isolated in the aquatic and terrestrial ecosystems differed substantially indicating that different CRESS DNA viromes exist in both land and water. The diversity of CRESS DNA viruses in seven different mollusc species (Amphibola crenata, Austrolvenus stutchburyi, Paphies subtriangulata, Musculium novazelandiae, Potamopyrgus antipodarum, Physella acuta and Echyridella menziesi) from Lake Sarah and the Avon-Heathcote estuary both in New Zealand, were also investigated. One hundred and forty nine novel viral genomes were recovered. Two CRESS DNA genomes were recovered from molluscs which have Rep-like sequences most closely related to those found in some bacterial genomes. Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1 (SsHADV-1) was originally isolated from fungal species Sclerotinia sclerotiorum in china and was later found in benthic sediments in New Zealand. As part of this study, SsHADV-1 was recovered from dragonflies (Erythemis simplicicollis, Ischnura ramburii and Pantala hymenaea) collected in Arizona and Oklahoma, USA suggesting a larger distribution of these viruses and not surprising given the near global distribution of S. sclerotiorum. Dragonfly larvae-associated circular DNA viruses (DflaCVs) that were originally isolated in Odonata larvae samples from three New Zealand lakes were later recovered from water, benthic sediment, worms and molluscs from one of the lakes initially sampled, suggesting that these viruses are ubiquitous in freshwater environments. This study has attempted to generate baseline data of CRESS DNA viruses in certain environments using NGS-informed approaches. This data was used to try and establish whether viral distribution in different samples types can potentially be explained by the food web interactions between different samples types. Although the analysis did not show any significant relationships between sample type interactions and viral distribution a few common associations between Odonata larvae and benthic sediment were evident. This was expected as the larvae live within the sediment so it could be assumed that they potentially have similar CRESS DNA viral distribution. Although the distribution of viruses varied across sample types, molluscs proved the best sampling tool for isolating largest numbers of CRESS DNA viruses in an ecosystem with extensive diversity. Overall, this research demonstrates the applications of NGS for investigating the diversity of CRESS DNA viruses. It demonstrates that some sample types such as Odonata in terrestrial systems and molluscs in aquatic environments, can be used as effective sampling tool to determine the diversity of CRESS DNA viruses in different environments as well as detecting previously isolated viruses. The CRESS DNA viruses isolated in this body of work provides baseline data that can potentially be used in future research to investigate hosts of these viruses and their interactions with hosts and potential flow in their environments.

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  • From Disordered Bosons to Dipolar Fermions - Theoretical Studies in Ultracold Atoms

    Towers, Joseph (2015)

    Doctoral thesis
    University of Otago

    We use numerical simulation to study ultracold, quantum degenerate, atomic gases. In the first part of the thesis we study the effects of disorder, introduced via a bichromatic optical lattice, in one and two dimensional systems. We employ the Aubry-Andr\'{e} model and use time-dependent numerical simulations to investigate the disorder dependent transition to strong localisation present in the model. Weak s-wave interactions are added to the model and we observe the interaction between localisation and interaction induced self-trapping. We then add a tilted lattice potential to the model. In the homogeneous model this induces Bloch oscillations. While one might expect that a strong enough force will break the strong localisation or self-trapping, within the bounds of the single-band model, the trapping effect of the Bloch oscillations reinforces both of the other effects leading to increased confinement, albeit lacking the clear single frequency oscillation signature of pure Bloch oscillations. Along with the two dimensional bichromatic optical lattice we add a term to the Hamiltonian equivalent to that of a uniform external magnetic field on charged particles. Since the experimental realisation of this model would employ neutral atoms, the magnetic field is synthetic, the equivalent effect being produced by an appropriate set of lasers and magnetic fields. We show that in the ballistic regime (weak bichromatic disorder) the system displays positive magnetoresistance. Conversely in the strong localisation regime the system exhibits negative magnetoresistance. In the latter part of the thesis we use density functional theory to calculate the ground-state density of a harmonically trapped dipolar Fermi gas. We then use these to calculate the lowest energy collective mode oscillation frequencies under the hydrodynamic approximation. We find that increasing the strength of the dipoles has the effect of increasing the mode frequencies. The increase saturates for large dipole strengths. We verify this analytically and show that such is due to the local nature of the two dimensional energy functional and not dependent on the specific equation of state. We employ an average density approximation to construct an energy functional for the inhomogeneous, 2D degenerate Fermi gas. The ground-state densities for a cylindrically symmetric harmonic trap are compared to the Kohn-Sham results, showing extremely good agreement in the tail region and good agreement with the exact ground-state energy. We then do the same for higher order polynomial traps and obtain improved agreement for higher degree.

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  • An Improved Human Anxiety-Specific Biomarker: Frequency Band, Modality Specificity, Personality, Pharmacology, and Source Characterisation

    Shadli, Shabah Mohammad (2015)

    Doctoral thesis
    University of Otago

    Anxiety disorders are among the most common mental illness in the western world with a major impact on disability. But their diagnosis has lacked objective biomarkers. McNaughton and colleagues previously developed a human EEG anxiety biomarker, goal-conflict-specific-rhythmicity (GCSR) in the stop signal task (SST). However, their version of the SST had some statistical limitations and was not suitable for clinical translation because of the narrow band GCSR and frequency shifts between experiments. Our aim was to modify the SST in a way that would overcome all the statistical limitations and produce larger amplitude GCSR. Go-stop (approach-avoidance) conflict in the SST generates rhythmic activity in the right frontal area as a result of activation of the behavioural inhibition system. We developed an SST in which short and long stop signal delays (SSDs) were controlled by average Go reaction time, while intermediate SSDs tracked 50% correct stopping to maximise goal conflict. This new procedure provides balanced numbers of trials across delay groups and prevents overlap in their values. Right frontal (F8) GCSR was extracted as the difference in EEG Fourier power between matching stop and go trials of a quadratic contrast of the three delay values (subtraction of average EEG power of short and long SSDs from the EEG power of intermediate SSD). Separate experiments assessed frequency spectrum (with both visual and auditory stop stimuli), personality relations, drug sensitivity (both auditory and visual stop stimuli) and source localisation. GCSR had a frequency range (4-12Hz) similar to that of rodent hippocampal rhythmical slow activity (RSA); correlated significantly with trait anxiety scores in initial and later blocks; and was reduced by three chemically distinct anxiolytic drugs in the auditory SST (administered double-blind): buspirone (10mg), triazolam (0.25mg), and pregabalin (75mg) and two chemically distinct anxiolytics; buspirone (10mg) and triazolam (0.25mg) in the visual SST. This anxiolytic drug sensitivity was similar to that of the rodent RSA assay from which GCSR was derived. GCSR was located in the medial frontal gyri, right inferior frontal gyri and superior frontal gyri, known to control SST stopping. GCSR, measured in our new form of the SST should be suitable as a biomarker for one specific type of anxiety disorder in testing of groups of anxiety disorder patients and in the development of measures suitable for individual diagnosis.

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  • Seizure-induced cardiomyopathy: Benefit of Atenolol

    Read, Morgayn (2015)

    Doctoral thesis
    University of Otago

    Epilepsy affects 1-2% of the population in New Zealand and is associated with an increased mortality rate of two to three times that of the general population. This thesis examines the effect of seizures on cardiac function, as it is hypothesised that seizure-induced activation of the sympathetic system produces electrographic (ECG) abnormalities, cardiac dysfunction and structural damage. Using a rodent model, seizures were induced using the excitotoxin, kainic acid, either subcutaneously or via an intrahippocampal drug cannula. The first section of this study demonstrated that systemic kainic acid administration produced generalised seizure activity developing to status epilepticus. Kainic acid administration produced an immediate drop in heart rate (by 28%) associated with bradyarrhythmias. This was followed by a progressive increase in seizure severity which coincided with the development of tachycardia, QTc prolongation and T wave elevation. Heart rate variability analysis demonstrated that seizure activity resulted in significant changes in autonomic function. Prophylactic therapy with atenolol or clonidine attenuated seizure-induced ECG changes and preserved normal cardiac morphology. The second half of this thesis used an improved model of seizure in which kainic acid was administered directly into the hippocampus to prevent possible systemic effects. The results in this study clearly demonstrated that seizures produced cardiac dysfunction, particularly changes in heart rate, QTc interval and blood pressure. Seizure-induced cardiac dysfunction resulted in significant structural damage as early as 48 hours which was still present up to 28 days after the original seizure induction. Assessment of autonomic function using various techniques demonstrated that seizures resulted in an increase in plasma noradrenaline levels and enhanced sympathetic dominance at 48 hours. The seizure-induced tachycardia which ensued resulted in the development of dilated cardiomyopathy with significant cardiac structural injury. The formation of cardiac micro-lesions and fibrotic deposition is suggested to contribute to left ventricular dysfunction and an increased susceptibility to arrhythmia induction. Intervention therapy with atenolol, 60 minutes post seizure induction, preserved cardiac function and structure. Importantly, atenolol reduced the susceptibility to arrhythmia onset, which has been reported as a contributor to sudden death in epilepsy. Interestingly, atenolol treatment during seizures also reduced EEG and behavioural score severity and protected the hippocampus from injury. Attenuation of seizure activity with diazepam did not reduce the extent of cardiac dysfunction. Diazepam-treated animals had significantly higher blood pressure, left ventricular dilation and an increased susceptibility to arrhythmia induction. However, combination therapy with atenolol and diazepam, proved effective at protecting both the heart and brain following seizure activity. This thesis has consistently demonstrated that atenolol administration (prophylactic or intervention) offers significant protection against seizure-induced cardiomyopathy. Atenolol, therefore, should be considered for clinical use, prophylactically in epilepsy or as a rescue intervention during status epilepticus. Importantly, this study clearly demonstrates that atenolol in combination with diazepam offers superior therapeutic benefit, over either monotherapy, in an animal model of status epilepticus.

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  • Environmental controls on the physiology of the marine coccolithophore Emiliania huxleyi strain NIWA 1108

    Feng, Yuanyuan (2015)

    Doctoral thesis
    University of Otago

    Anthropogenic activities have affected the global climate rapidly; different environmental factors important for oceanic productivity have been altered. The concurrent changes in multiple environmental drivers affect the physiology of marine phytoplankton, both individually and interactively, in a complex way. Emiliania huxleyi, the most abundant and widely-distributed coccolithophore in the ocean, is a model organism for understanding the marine carbon cycle. As a calcifying species, E. huxleyi is considered particularly susceptible to the increasing surface seawater CO2 concentration and decreasing pH, termed ocean acidification. The thesis presents a series of step-wise studies on the controls of five environmental drivers (nitrate concentration, phosphate concentration, irradiance, temperature and CO2) on the physiology of a southern hemisphere E. huxleyi strain isolated from the Chatham Rise, New Zealand. The goal of this thesis is to examine the importance of ocean acidification relative to four other environmental drivers both individually and interactively on the physiology of the ecologically important coccolithophore species. First, E. huxleyi strain NIWA 1108 was subjected to a series of semi-continuous incubation experiments by changing the conditions of one environmental driver at a time. The importance of each environmental driver on each measured physiological metric of E. huxleyi was ranked using a semi-quantitative approach by comparing the percentage change caused by each environmental driver on the measured physiological metrics at the projected conditions for the year 2100 relative to the present day conditions in the Chatham Rise, New Zealand. The results reveal that a 33% decrease in nitrate concentration played the most important role in controlling the growth, photosynthetic and calcification rates of E. huxleyi; rising pCO2 decreased the calcification:photosynthesis and cellular particulate inorganic carbon:particulate organic carbon ratios the most; warming was the major driver controlling both cellular particulate organic carbon and particulate inorganic carbon contents; and nutrient concentrations were the most important drivers regulating the cellular particulate nitrogen and cellular particulate phosphorus contents of E. huxleyi. Then a two-way (ocean acidification plus changes in either nitrate concentration, phosphate concentration, irradiance or temperature) and multiple factorial (manipulation of all the five environmental drivers) manipulation experiment was conducted. The results exhibited an interesting connection with the single environmental driver effects: interaction of ocean acidification and a 33% decrease in nitrate concentration had the largest synergistic negative effects on most of the E. huxleyi physiological metrics among all the two-way factorial manipulations. The simultaneous manipulation of all the five environmental drivers to the projected future (2100) conditions had the most prominent negative effects on the growth, photosynthetic and calcification rates of E. huxleyi. Finally, the gene expression study suggests that changing pCO2 probably affects E. huxleyi photosynthesis and calcification through regulating the carbon concentrating mechanism and pH homeostasis at the molecular level. Furthermore, the substantial down-regulation of most of the investigated genes associated with inorganic carbon acquisition and calcification by multi-factorial manipulation of all the five environmental drivers indicates a link between significant suppression of functional genes and the substantially decreased physiological rate processes (growth, photosynthetic and calcification rates) in E. huxleyi. Overall, the thesis reveals that other environmental drivers may play more important roles than ocean acidification in regulating the physiological responses of E. huxleyi, and suggests that the interplay between ocean acidification and other drivers is likely to have antagonistic, additive or synergistic effects on different physiological metrics of E. huxleyi. The thesis contributes to our understanding of how the physiology of E. huxleyi will respond to the concurrent changes of multiple environmental drivers.

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  • CD169 mediates the capture of exosomes in the spleen and lymph node

    Saunderson, Sarah Charlotte (2015)

    Doctoral thesis
    University of Otago

    Exosomes are lipid bound nanovesicles that are formed via the inward budding of the endosomal membrane, then released upon fusion of the endosomal limiting membrane with the plasma membrane. The majority of exosome studies involve the use of exosomes from bone marrow-derived dendritic cells or immortalised cell lines. This research project has focused on exosomes derived from primary B cells in response to T cell signalling, in particular via the CD40 and the interleukin-4 receptors. The fate of exosomes following their release is largely unknown. However as we have previously identified that B cell-derived exosomes are enriched in the antigen presenting molecules major histocompatibility complex class I (MHC-I), MHC-II and immunoglobulin, this may implicate B cell-derived exosomes in the transfer of antigen. We have sought to address the physiological role of primary B cell-derived exosomes and their interactions with other cells within secondary lymphoid tissue in vivo. We identified sialoadhesin (CD169; Siglec-1) as a novel mechanism for the specific capture of B cell-derived exosomes via surface expressed α2,3-linked sialic acids. In particular, exosomes were captured by marginal metallophilic and subcapsular sinus macrophages within the spleen and lymph node respectively. In vitro binding assays performed on naïve spleen and lymph node tissue sections confirmed that exosome binding to CD169 was not solely due to preferential fluid flow to these areas. Despite the presence of this specific capture mechanism, the circulation half-life of exosomes in the blood of wild-type and CD169-deficient mice was similar, with a short half-life of approximately two minutes. This likely indicated the presence of CD169-independent capture and uptake mechanisms. However immunofluorescent microscopy revealed intravenously or subcutaneously administered exosomes displayed altered distribution within CD169-deficient compared to wild-type mice. In vivo, exosomes freely accessed the outer marginal zone rim of SIGN-R1+ marginal zone macrophages and to a lesser degree also the F4/80+ macrophages in the spleen. In the lymph node, exosomes appeared less well contained to the subcapsular sinus and had migrated into the medullary sinus. In vivo exosomes were efficiently captured in a CD169-independent manner by Kupffer cells within the liver of both wild-type and CD169-deficient mice, but this capture was not observed in vitro indicating this capture to be purely a physiological response. Interestingly, although the human splenic marginal zone contains relatively few CD169+ macrophages, a pilot experiment involving one human spleen sample revealed that B cell-derived exosomes were also specifically captured in a marginal zone binding pattern using an in vitro binding assay. While this capture within the human spleen sample was likely CD169-independent, the striking similarity between exosome binding within murine and human splenic tissue, implicates the splenic marginal zone as a conserved mediator of exosome capture across species. We next established a role for B cell-derived exosomes in the promotion of in vivo T cell proliferative and cytotoxic responses. In vivo endogenous cytotoxic T lymphocyte (CTL) responses to exosomal antigen showed an absolute dependence on the presence of CD4+ T cells, CD8+ T cells and natural killer (NK) cells, where the loss of any one of these subsets led to the complete loss of CTL response. Furthermore, NK cell involvement appears independent of interferon-gamma. Interestingly, in the absence of CD169, exosomal antigen induced an enhanced CTL response. This implicates CD169+ macrophages in suppression of the immune response to exosomal antigen, possibly via limiting exosome access to potent antigen presenting cells. While the precise pathway for exosome induced in vivo CTL responses still remains to be determined, we have identified that CD4+ T cells, CD8+ T cells and NK cells each play a critical role in the response to exosomal antigen.

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  • A study of some New Zealand natural products.

    Jogia, Madhu Kant (1985)

    Doctoral thesis
    University of Otago

    xii, 348 leaves :col. ill. ; 30 cm. Includes bibliographical references. University of Otago department: Chemistry

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  • Stuck in the middle or clued up on both? Language and identity among Korean, Dutch and Samoan immigrants in Dunedin

    Johri, Roopali (1998)

    Doctoral thesis
    University of Otago

    xiv, 332 p. :ill. ; 30 cm. Includes bibliographical references. University of Otago department: Anthropology. "24 February 1998."

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  • Population biology, pre-settlement processes and recruitment in the New Zealand sea urchin, Evechinus chloroticus Valenciennes (Echinoidea: Echinometridae)

    Lamare, Miles David (1997)

    Doctoral thesis
    University of Otago

    xxi, 257 leaves :ill., maps ; 30 cm. Includes bibliographical references. "May 1997." University of Otago department: Marine Science.

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  • Rocky shore snails and their trematodes: new systems, new parasites, new insights

    O'Dwyer, Katie (2015)

    Doctoral thesis
    University of Otago

    The number of parasite species being described is still rising sharply, with little sign of slowing down. This illustrates a limitation in our current understanding of host-parasite interactions. The need for improved knowledge of the biodiversity of parasites and of their effects is especially important due to the realised and potential impacts of parasites across a wide variety of domains, including in clinical, environmental and agricultural practices. Concurrently, as data mounts on specific biological systems, from a more macroecological viewpoint there is an intensifying search for common patterns across systems, with the aim of providing clearer insights into the general properties of host-parasite interactions. This thesis encompasses several of these challenges, namely, parasite species descriptions, parasite impacts and the search for general properties affecting host-parasite interactions. The novel study systems investigated were Australasian rocky shore periwinkle or littorinid snails, and their trematode parasites. Previously, parasites of periwinkle snails were well studied in the Northern Hemisphere, though nothing is known about Southern Hemisphere periwinkles. In New Zealand, two snail species were studied and a total of five parasite species found (Chapter Two). In Australia, a single snail species was found to host five parasites also (Chapter Three). An important knowledge gap was filled with the finding of one of these parasites in Australia providing the first record of a snail host for the trematode family Gorgocephalidae. All parasite species were described using an integrative taxonomical approach, which incorporated line drawings, scanning electron microscopy and molecular analyses. Low prevalence was recorded for most parasites in New Zealand, therefore further experimental work focused on the most abundant parasite, Parorchis sp. NZ (family Philophthalmidae). This parasite displayed an unusual biology whereby it can abbreviate its development, possibly as an adaptation to stressful conditions. To investigate this, the incidence of the abbreviated life cycle (precocious encystment) was studied in response to host stress due to desiccation. Although the results confirmed desiccation as a host stress, it appeared to have little effect on the development pattern of the parasite (Chapter Four). The focus then turned to the effect of the parasite on its host and specifically to the impact of infection on microhabitat choice of snails (Chapter Five). The choice of microhabitat on a rocky shore may influence a snail’s success in withstanding dislodgement, due to wave exposure or predation. Interestingly, the results showed that infected snails spend more time on the rock surface than in crevices, possibly leading to enhanced parasite transmission, and inevitably to a higher risk of mortality for infected snails. Finally, to gain a broader understanding of the ecological drivers underpinning interspecific variation in parasite species richness among periwinkles, a comparative analysis was carried out using data compiled from the literature (Chapter Six). I quantified the contribution of both evolutionary history and ecology to observed patterns of parasite species richness, and found that both latitude and host phylogeny accounted for much of the variation in how many trematode species exploit particular periwinkle species.

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  • Cogere Intrare: The Fourth-Century Abandonment of Christian Pacifism and the Rise of the Militant Church

    Manby, Aaron Christopher (2015)

    Doctoral thesis
    University of Otago

    The fourth and fifth centuries of the Common Era saw the Christian Church, such as it can be uniformly described during a time of great internal turmoil, transform from an influential minority long despised by pagan leadership to the most powerful religious institution in the Roman world. One noteworthy result of this transitional phase was the abnegation by Church leaders of the corporate ethic of non-violence, traditionally rooted in Christ’s response to persecution, in favor of coerced fidelity to the ecclesiastical institution. Because of his indisputable influence over the systematic justification of religious coercion, historians and theologians have traditionally traced the Christian approbation of holy violence to Augustine of Hippo. Those who do not typically offer an alternative scenario in which the Church was never really pacifist to begin with, but rather had always embraced the legitimacy of violence to the extent that their status as a persecuted minority allowed. My argument responds to both perspectives. I first illustrate that the persecuted Church did indeed espouse a unified and principled pacifism. I then argue that the ecclesiastical transition from pacifism to coercion was more or less complete by the year 408 when Augustine composed his defense of cogere intrare. Finally, I offer an account of how this transition came about, ultimately focusing upon how ecclesiastical leaders such as Lactantius and Eusebius of Caesarea began to redefine the tertium genus identity as well as the eschatological tenets of patience, martyrdom, and divine wrath in response to the unanticipated conversion of Constantine. In Part One I demonstrate that during the era of persecution these elements had been used to empower non-violence in the face of Roman brutality. In Part Two I then examine how the fourth-century reformulation of these elements, in combination with Constantine’s transition from pax deorum to pax dei, facilitated the rapid transition from pacifism to coercion. I conclude that, as a result of this new confluence, by the mid-fourth century the justification of violence in the name of Christ had been established, and the groundwork laid out for later systematic apologies for holy Christian violence.

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  • Roles and expression of Fgf/RTK signaling modulators, Sproutys and Sulfs, in Xenopus limb development and regeneration

    Wang, Yi-Hsuan (2015)

    Doctoral thesis
    University of Otago

    The amphibian model, Xenopus laevis, is capable of perfect epimorphic limb regeneration prior to metamorphosis. It had been indicated that the amphibians’ abilities to regenerate lost structures may be attributed to certain intrinsic factors, such as unique patterns of gene expression following trauma. Transcriptome studies and more recent molecular analyses have shown that members of the fibroblast growth factor (fgf) families are re-expressed in regenerating Xenopus limb. The expression of certain fgf members, such as fgf-8 and -10, plays positive roles in successful limb regeneration in Xenopus. Therefore, the functions of this group of morphogens during regeneration are of particular interest to understanding the secrets to regenerative success in regenerative taxa, such as the clawed frogs. Members of the Fgf are morphogens that direct cell differentiation and functions during developments. Their biological activities are regulated by a variety regulators, such as the intracellular inhibitor, Sproutys (Spry), and the extracellular heparan sulfates (Sulf). These modulators act on the Fgf-triggered mitogen-activated protein kinase (MAPK) signaling cascade at various points, influencing the eventual biological response. We hypothesised that, similar to the reports in other vertebrate models, Xenopus spry and sulf also play important roles in regulating Fgf activities in limb development, and possibly regeneration. This was indicated by in situ hybridisation data described in Chapter 3 and 4, showing that the expression profiles of three of the Xenopus spry and two sulf genes either complemented or overlapped with known region of the fgfs expression during development and regeneration. The developmental expression patterns of the Xenopus spry and sulf genes were distinct from their avian and murine homologues. They also demonstrated varying levels of expression in either the proliferating blastema or the apical epidermal cap in regenerating limb. These data indicate unique functions of the two sets of genes compared to their avian and mammalian homologues. Based on these observations, we speculate that fine manipulation of the Fgf- activated MAPK pathways may be achieved by controlling the expression of spry and/or sulf. To test the last hypothesis, we attempted functional studies by generating a heat shock inducible spry-1a over-expressing X. laevis line. Transgenic frogs carrying a novel heat shock inducible DNA-directed RNAi transgene system were also created, in hope to allow for sequence-specific gene knock-down/-out experiments in Xenopus. Regrettably, these experiments did not result in any usable data. In conclusion, this study provides the first detailed expression profiles of the Xenopus spry and sulf during limb development and regeneration. The dynamic and distinct expressions of these genes in Xenopus compared to the other model systems suggest unique functions of these genes in the amphibian model that may also be related their more superior regenerative ability. Therefore, further functional study targeting the effects of these Fgf regulators in limb regeneration is warranted. Finally, although the functional experiments using transgenics described in Chapter 3 and 5 did not yield any usable data, we believe that the detailed procedures discussed here will be useful to future studies.


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  • Sports Fans' Psychological Ownership in the Japanese Professional Football League

    Sumida, Ken (2015)

    Doctoral thesis
    University of Otago

    Sport marketing studies are examined from two perspectives that fans are both customers of and members of teams. Both of these perspectives are based on the idea that fans belong to teams. This thesis challengers that idea and suggests that teams belong to fans, even though they do not own it in the legal sense. Understanding fans from this fresh perspective allows scholars to add value to the sport marketing discipline and marketers to make their marketing approach effective. The purpose of this study is to investigate sports fans’ psychological ownership of teams. This thesis uses a mixed methods research design. In this design, initially, fans’ psychological ownership was qualitatively explored. Then the findings were quantified by applying psychometric methods (quantitative generalization). Both types of data were collected from two teams in the Japanese professional football league (J-League). The analysis of both of the qualitative and quantitative data provided important results. Fans’ psychological ownership was shaped and nourished within and through the complexity of fan culture. Specifically, symbolical meanings and individual experiences relevant to spectator sports consumption were interpreted by individual fans. In order for the individual fans to connect these meanings, they undertook sets of particular consumption practices or rituals. This study highlights that the rituals fans repeatedly undertake played a crucial role in shaping and fostering fans’ psychological ownership of the focal team and their fan-identity. The quantitative analysis showed that fans’ psychological ownership was psychometrically quantifiable and had positive relationships with fans’ involvement in value co-creation behaviours. Psychological ownership was shown as being a different psychological concept to team identification and organizational commitment. It can be expected that psychological ownership may be able to narrow gaps in the existing literature which the application of the concepts of team identification and organizational commitment has been unable to achieve. The contribution of this thesis was to show qualitative and quantitative evidence of the existence of psychological ownership in fans’ minds. The existence of psychological ownership is important for scholars or marketers in defining who sports fans are. There is a spectrum polarizing lowly-identified fans and highly-identified fans. In this spectrum, those who are in the middle of the spectrum are seen as ordinary fans. The study undertaken in this thesis showed that there are fans who hold a high degree of psychological ownership, but who place less emphasis on team identification.

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  • Contextual factors affecting the development of digital library education in Vietnam

    Do, Van Hung (2015)

    Doctoral thesis
    Victoria University of Wellington

    In Vietnam the need for digital library education (DLE) has increased significantly in the last two decades. Educating staff to establish and manage digital libraries has become a critical issue. However, there are no DLE programmes offered by library and information management (LIM) education providers in Vietnam and we do not know why this is the case. The aim of this study is to investigate and understand the factors affecting the development of DLE for LIM practitioners in Vietnam. The interpretive study employed a qualitative approach and its findings are based on the analysis of data gathered in 17 individual interviews and 11 focus groups with key stakeholders, as well as from documentary evidence. The stakeholders involved in this study include LIM practitioners, LIM managers, LIM lecturers, library school deans, government policy makers, academic library directors, professional association chairpersons and LIM students. To guide the data gathering and analysis, an initial conceptual model of factors affecting DLE was developed from three sources: Fullan’s Educational Change theory, Nowlen’s Performance Model in continuing education for practitioners, and Rogers’s Diffusion of Innovations theory. The study found seven major factors were affecting the development of DLE in Vietnam: the government, the information technology infrastructure, the prevailing social and cultural values, the efforts of change agents, the attitudes of key stakeholders, the characteristics of DLE design, and the nexus of the educational needs of library staff and the libraries in which they were working. Of these the government factor was the most influential. These factors were inter-related and affected DLE development at different levels. The initial conceptual model was revised based on the study's findings. The revised model provides a contribution to educational change theories relevant to the identification and understanding of factors affecting professional educational programmes in universities in developing countries. The study’s findings are also of value to governments, libraries, library schools and library associations for developing relevant policies and new curricula for DLE, and for establishing new professional development programmes in DLE for library staff.

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  • Supporting the use of algorithmic design in architecture: An empirical study of reuse of design knowledge

    Globa, Anastasia (2015)

    Doctoral thesis
    Victoria University of Wellington

    This thesis tests the reuse of design knowledge as a method to support learning and use of algorithmic design in architecture. The use of algorithmic design systems and programming environments offer architects immense opportunities, providing a powerful means to create geometries and allowing dynamic design exploration, but it can also impose substantial challenges. Architects often struggle with adopting algorithmic design methods (translating a design idea into an algorithm of actions), as well as with the implementation of programming languages, the latter often proving frustrating and creating barriers for both novice and advanced software users. The proposition explored in this thesis is that the reuse of design knowledge can improve architects’ ability to use algorithmic design systems, and reduce the barriers for using programming. This study explores and compares two approaches as a means of accessing and reusing existing design solutions. The first approach is the reuse of abstract algorithmic ‘Design Patterns’. The second is the reuse of algorithmic solutions from specific design cases (Case-Based Design). The research was set up as an experimental comparative study between three test groups: one group using Design Patterns, a second group using Case-Based Design, and the control group. A total of 126 designers participated in the study providing sufficient numbers within each group to permit rigorous studies of the statistical significance of the observed differences. Results of this study illustrate that the systematic inclusion of the Design Patterns approach to the learning strategy of programming in architecture and design, proves to be highly beneficial. The use of abstract solutions improves designers’ ability to overcome programming barriers, and helps architects to adopt algorithmic design methods. The use of Design Patterns also encourages design exploration and experimentation. The use of the Case-Based Design approach seems to be more effective after designers and architects, who are novices in programming, gain more experience with the tool. It encourages more focused reasoning, oriented to the realisation of a particular (originally intended) design outcome. The contribution of this research is to provide empirical evidence that the reuse of abstract and case-based algorithmic solutions can be very beneficial. Results of this study illustrate that both reuse methods can be strategically integrated into design education and architectural practice, supporting learning and use of algorithmic design systems in architecture. The study also identifies potential weaknesses of each approach, proposing areas which could be addressed by future studies.

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  • Public Streets for Multicultural Use: Exploring the Relationship between Cultural Background, Built Environment, and Social Behaviour

    Lesan, Maryam (2015)

    Doctoral thesis
    Victoria University of Wellington

    Public space is the domain of interest for urban planners and designers and the most important type of public space is streets. Public spaces, and particularly busy streets in urban centres, provide opportunities for people to meet, often by chance. As cities become increasingly multi-cultural in population the use and nature of public space reflects this. The best public spaces cater to the needs of all who use them and in multicultural societies this also means they must meet the expectations of people from different cultures. Many scholars have challenged the tendency for streets to be conceived of as movement channels, often at the expense of their use as social space. Streets have traditionally catered to a broad array of activities including walking, cycling and standing. Streets that facilitate such activities are preferred by the public. Streets in multicultural societies are also where people from different ethnic backgrounds find opportunities to interact. When public spaces are successful, they will increase opportunities to participate in communal activities. Spatial design is a critical success factor for streets; a goal for urban designers must be to create spaces where people from different social and cultural backgrounds value the public spaces they have access to. As cities become more multicultural the challenge is to design and manage spaces that appeal to the breadth of cultures that are represented in the population. Such public spaces are described in the literature as being more public. However, there is presently little information to help planners and designers to realise streets that appeal to people having different socio-cultural backgrounds. The research aims to identify those characteristics that will promote and maintain cultural diversity in the context of neighbourhood commercial streets in New Zealand’s multi-cultural society. The research is undertaken in two stages. “Stage One” makes use of ethnographic fieldwork as a basic method, complimented by structured field observations using a behavioural mapping procedure, and surveys of users of the streets. This stage provides data on specific streets and their usage through three case studies. Stage Two” utilises online surveys that generated data in relation to street visualizations. This stage seeks to understand what design characteristics and furniture arrangements are associated with stationary, social and gathering activities of people and to define design characteristics of footpath spaces preferred by each cultural group and all groups collectively. The main conclusion from this research is that retail activities remain the main concern of people in multi-cultural streets. Management and higher level planning of retail activities on the streets could encourage and motivate possible tenants in order to enrich the retail assortment of the street and provide a means for social and cultural diversity. In addition to business activities, spatial design characteristics are found to have an influence on people’s behaviour and activity. The findings of this research suggest that retail and business activities, together with the design and skilful management of the public areas, could support a broader range of static and social activities among people of various cultural backgrounds. The thesis makes recommendations for urban planners and designers based on the findings of the research.

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  • HIV risk and preventive behaviours among the intimate partners of men who inject drugs in Malaysia

    Abdul Manaf, Rosliza (2015)

    Doctoral thesis
    University of Otago

    Background: People who inject drugs (PWID) comprise the highest percentage of diagnosed HIV cases in Malaysia. The female intimate partners of such men risk being infected with HIV through sexual contact. There has been no study in Malaysia, and few internationally that have examined the experiences of these women and how they protect themselves against HIV. Methods: A concurrent mixed-methods study comprising of a survey and interviews was conducted among the intimate female partners of men who inject drugs in the urban and rural areas around Kuala Lumpur and Selangor, Malaysia. Through respondent driven sampling and other sampling strategies, 221 women were recruited in the survey. A subsample of 22 women representing a range of ethnicities, marital status and localities were interviewed individually. The survey was analysed to examine factors associated with HIV preventive behaviour. The interviews were analysed using thematic analysis to identify recurring themes. Initial data analyses of the survey and interviews were done separately, after which they were combined and triangulated to address the research questions. Findings: The results found that these female intimate partners of PWID are vulnerable to HIV, reflected by the HIV prevalence (6.3%) reported among them being much higher than that in the general Malaysian population. While 7.7% of women reported having HIV positive partners, nearly half (45.7%) were not aware of their partner’s HIV status. Unprotected sex was common, with only 19.5% using condoms regularly with their partners. The high prevalence of HIV among their partners and the low use of condoms in their relationship shows the heightened risk faced by the women. There was a positive response to the possibility of using female-controlled HIV protective methods, with 69.0% agreeing they might use them if available. Nearly two thirds felt they need to ask their partner’s permission before doing so, with married women and Muslims more likely to report it important to ask their husband’s permission. From the interviews it was clear that HIV prevention practices were not easy for many of these women. While inability to negotiate condom use was the main issue, factors such as poor risk perception, relationship power imbalances, socio-cultural norms, inadequate knowledge of HIV prevention and socio-economic hardship synergistically increased their vulnerability to HIV. The challenges of consistent condom use within a long-term relationship call for other preventive strategies for HIV prevention among this population. These need to include strengthening the HIV screening of PWID and encouraging disclosure of HIV status to their partners, while at the same time empowering women by providing alternative prevention methods that women themselves could control. Conclusion: This thesis has unfolded the realities faced by female intimate partners of PWID in Malaysia, not just in the issue of HIV prevention but also the challenges in their daily lives. The alarming risk faced by the women and the complex nature of this issue demands a well-planned and comprehensive intervention that could improve the resilience of the women towards HIV. It is hoped that the findings from this thesis are able to reflect the women’s voices and provide the opportunity for their problems to surface for appropriate attention by the relevant bodies.

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  • Radical Development: the developmental consequences of oxidative stress in zebrafish

    Newman, Trent (2015)

    Doctoral thesis
    University of Otago

    Oxidative stress, an imbalance in the cellular redox systems, could be a major influence on organism development. To investigate this possibility I carried out basic research into the antioxidant systems in the zebrafish developmental model. Of interest were ways of measuring stress, ways of inducing stress, the molecular pathways involved, and the developmental consequences for the zebrafish. Peroxiredoxin 3 (Prdx3), the protein responsible for peroxide reduction in the mitochondia, was investigated as an indicator of oxidative stress in zebrafish. The custom antibody used in this study was capable of detecting recombinant zebrafish Prdx3 in both reduced and oxidized states. In zebrafish protein extracts the oxidized dimer ran at 37 kDa while the reduced monomer ran at 23 kDa. In addition, there was also a 15 kDa small band detected in zebrafish extracts that might represent a Prdx3 cleavage product. Immunodetection of Prdx3 redox state in zebrafish protein extracts has potential as a way of measuring the level of mitochondrial oxidative stress in vivo. Several approaches were taken to characterise the functional role of Prdx3 in the developing zebrafish embryo. Insight was gained from in situ hybridisation which showed the prdx3 transcript to be expressed in the developing haematopoietic system. Knockdown of Prdx3 in zebrafish could have allowed the function of Prdx3 to be tested in zebrafish. Unfortunately, no knockdown of Prdx3 was observed in zebrafish embryos following morpholino injection. To this end custom TALENs were constructed capable of targeting the prdx3 locus but a mutant line has not yet been established. The level of oxidative stress during embryogenesis is a largely unexplored influence on adult phenotype and subsequent generations. To induce oxidative stress in the embryo, the chemical auranofin (AFN) was used to inhibit antioxidant defences. Static embryonic exposure to AFN resulted in developmental defects, including cerebral haemorrhaging at high doses and jaw malformation at lower doses. Oxidative stress was increased in embryos exposed to AFN, as evident by the DNA damage resulting from the 5 μM dose and the increased redox state observed with the 1 μM dose. Embryos generated a transcriptional response as early as 1 dpf after AFN exposure beginning at 6 hpf. The most responsive transcripts were prdx1 and gstp1 which in response to 5 μM AFN were increased over 3 and 7 fold by 1 dpf, respectively. To investigate the long-term consequences of oxidative stress, embryos exposed to the low 0.5 μM AFN dose between 6 and 24 hpf were raised to adulthood. Both cohorts 1 and 2 showed lower odds of breeding success following the AFN treatment. Within this AFN treatment group the breeding success was lower in outcrosses of treated females. Fertilization rate was also decreased in incrosses of treated fish suggesting an effect on both males and females. Males from the treatment arms had a trend towards less motile sperm, potentially contributing to the reduced fertilization rate. There was no difference in the incidence of developmental defects in the offspring from the cohort treatment arms. Research into the mechanisms of environmentally-induced phenotypic change, and its transmission between generations, requires models in which to do so. This study contributes a basis for undertaking longitudinal cohort studies in the zebrafish. In addition, the findings support the idea that the environmental conditions during development can have long-term effects on adult health. This thesis will serve as a useful reference for hypothesis generation and the design of future studies aiming to investigate environmental effects on development and inheritance in the zebrafish model.

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  • A hierarchy of symbols : Samoan religious symbolism in New Zealand

    Duncan, Betty Kathleen (1994)

    Doctoral thesis
    University of Otago

    viii, 263 leaves :ill. (some col.), col. map ; 30 cm. Includes bibliographical references. University of Otago department: Religious Studies

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